root/drivers/gpio/gpiolib.c

DEFINITIONS

1. desc_set_label
2. gpio_to_desc
3. gpiochip_get_desc
4. desc_to_gpio
5. gpiod_to_chip
6. gpiochip_find_base
7. gpiod_get_direction
8. gpiodev_add_to_list
9. gpio_name_to_desc
10. gpiochip_set_desc_names
11. gpiochip_allocate_mask
12. gpiochip_alloc_valid_mask
13. gpiochip_init_valid_mask
14. gpiochip_free_valid_mask
15. gpiochip_line_is_valid
16. linehandle_ioctl
17. linehandle_ioctl_compat
18. linehandle_release
19. linehandle_create
20. lineevent_poll
21. lineevent_read
22. lineevent_release
23. lineevent_ioctl
24. lineevent_ioctl_compat
25. lineevent_irq_thread
26. lineevent_irq_handler
27. lineevent_create
28. gpio_ioctl
29. gpio_ioctl_compat
30. gpio_chrdev_open
31. gpio_chrdev_release
32. gpiodevice_release
33. gpiochip_setup_dev
34. gpiochip_machine_hog
35. machine_gpiochip_add
36. gpiochip_setup_devs
37. gpiochip_add_data_with_key
38. gpiochip_get_data
39. gpiochip_remove
40. devm_gpio_chip_release
41. devm_gpiochip_add_data
42. gpiochip_find
43. gpiochip_match_name
44. find_chip_by_name
45. gpiochip_irqchip_init_hw
46. gpiochip_irqchip_init_valid_mask
47. gpiochip_irqchip_free_valid_mask
48. gpiochip_irqchip_irq_valid
49. gpiochip_set_cascaded_irqchip
50. gpiochip_set_chained_irqchip
51. gpiochip_set_nested_irqchip
52. gpiochip_set_hierarchical_irqchip
53. gpiochip_hierarchy_irq_domain_translate
54. gpiochip_hierarchy_irq_domain_alloc
55. gpiochip_child_offset_to_irq_noop
56. gpiochip_hierarchy_setup_domain_ops
57. gpiochip_hierarchy_add_domain
58. gpiochip_hierarchy_is_hierarchical
59. gpiochip_populate_parent_fwspec_twocell
60. gpiochip_populate_parent_fwspec_fourcell
61. gpiochip_hierarchy_add_domain
62. gpiochip_hierarchy_is_hierarchical
63. gpiochip_irq_map
64. gpiochip_irq_unmap
65. gpiochip_irq_domain_activate
66. gpiochip_irq_domain_deactivate
67. gpiochip_to_irq
68. gpiochip_irq_reqres
69. gpiochip_irq_relres
70. gpiochip_irq_enable
71. gpiochip_irq_disable
72. gpiochip_set_irq_hooks
73. gpiochip_add_irqchip
74. gpiochip_irqchip_remove
75. gpiochip_irqchip_add_key
76. gpiochip_add_irqchip
77. gpiochip_irqchip_remove
78. gpiochip_irqchip_init_hw
79. gpiochip_irqchip_init_valid_mask
80. gpiochip_irqchip_free_valid_mask
81. gpiochip_generic_request
82. gpiochip_generic_free
83. gpiochip_generic_config
84. gpiochip_add_pingroup_range
85. gpiochip_add_pin_range
86. gpiochip_remove_pin_ranges
87. gpiod_request_commit
88. validate_desc
89. gpiod_request
90. gpiod_free_commit
91. gpiod_free
92. gpiochip_is_requested
93. gpiochip_request_own_desc
94. gpiochip_free_own_desc
95. gpio_set_config
96. gpiod_direction_input
97. gpiod_direction_output_raw_commit
98. gpiod_direction_output_raw
99. gpiod_direction_output
100. gpiod_set_debounce
101. gpiod_set_transitory
102. gpiod_is_active_low
103. gpiod_toggle_active_low
104. gpiod_get_raw_value_commit
105. gpio_chip_get_multiple
106. gpiod_get_array_value_complex
107. gpiod_get_raw_value
108. gpiod_get_value
109. gpiod_get_raw_array_value
110. gpiod_get_array_value
111. gpio_set_open_drain_value_commit
112. gpio_set_open_source_value_commit
113. gpiod_set_raw_value_commit
114. gpio_chip_set_multiple
115. gpiod_set_array_value_complex
116. gpiod_set_raw_value
117. gpiod_set_value_nocheck
118. gpiod_set_value
119. gpiod_set_raw_array_value
120. gpiod_set_array_value
121. gpiod_cansleep
122. gpiod_set_consumer_name
123. gpiod_to_irq
124. gpiochip_lock_as_irq
125. gpiochip_unlock_as_irq
126. gpiochip_disable_irq
127. gpiochip_enable_irq
128. gpiochip_line_is_irq
129. gpiochip_reqres_irq
130. gpiochip_relres_irq
131. gpiochip_line_is_open_drain
132. gpiochip_line_is_open_source
133. gpiochip_line_is_persistent
134. gpiod_get_raw_value_cansleep
135. gpiod_get_value_cansleep
136. gpiod_get_raw_array_value_cansleep
137. gpiod_get_array_value_cansleep
138. gpiod_set_raw_value_cansleep
139. gpiod_set_value_cansleep
140. gpiod_set_raw_array_value_cansleep
141. gpiod_add_lookup_tables
142. gpiod_set_array_value_cansleep
143. gpiod_add_lookup_table
144. gpiod_remove_lookup_table
145. gpiod_add_hogs
146. gpiod_find_lookup_table
147. gpiod_find
148. platform_gpio_count
149. gpiod_count
150. gpiod_get
151. gpiod_get_optional
152. gpiod_configure_flags
153. gpiod_get_index
154. fwnode_get_named_gpiod
155. gpiod_get_index_optional
156. gpiod_hog
157. gpiochip_free_hogs
158. gpiod_get_array
159. gpiod_get_array_optional
160. gpiod_put
161. gpiod_put_array
162. gpiolib_dev_init
163. gpiolib_dbg_show
164. gpiolib_seq_start
165. gpiolib_seq_next
166. gpiolib_seq_stop
167. gpiolib_seq_show
168. gpiolib_open
169. gpiolib_debugfs_init

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/bitmap.h>
   3 #include <linux/kernel.h>
   4 #include <linux/module.h>
   5 #include <linux/interrupt.h>
   6 #include <linux/irq.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/list.h>
   9 #include <linux/device.h>
  10 #include <linux/err.h>
  11 #include <linux/debugfs.h>
  12 #include <linux/seq_file.h>
  13 #include <linux/gpio.h>
  14 #include <linux/idr.h>
  15 #include <linux/slab.h>
  16 #include <linux/acpi.h>
  17 #include <linux/gpio/driver.h>
  18 #include <linux/gpio/machine.h>
  19 #include <linux/pinctrl/consumer.h>
  20 #include <linux/cdev.h>
  21 #include <linux/fs.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/compat.h>
  24 #include <linux/anon_inodes.h>
  25 #include <linux/file.h>
  26 #include <linux/kfifo.h>
  27 #include <linux/poll.h>
  28 #include <linux/timekeeping.h>
  29 #include <uapi/linux/gpio.h>
  30 
  31 #include "gpiolib.h"
  32 #include "gpiolib-of.h"
  33 #include "gpiolib-acpi.h"
  34 
  35 #define CREATE_TRACE_POINTS
  36 #include <trace/events/gpio.h>
  37 
  38 /* Implementation infrastructure for GPIO interfaces.
  39  *
  40  * The GPIO programming interface allows for inlining speed-critical
  41  * get/set operations for common cases, so that access to SOC-integrated
  42  * GPIOs can sometimes cost only an instruction or two per bit.
  43  */
  44 
  45 
  46 /* When debugging, extend minimal trust to callers and platform code.
  47  * Also emit diagnostic messages that may help initial bringup, when
  48  * board setup or driver bugs are most common.
  49  *
  50  * Otherwise, minimize overhead in what may be bitbanging codepaths.
  51  */
  52 #ifdef  DEBUG
  53 #define extra_checks    1
  54 #else
  55 #define extra_checks    0
  56 #endif
  57 
  58 /* Device and char device-related information */
  59 static DEFINE_IDA(gpio_ida);
  60 static dev_t gpio_devt;
  61 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
  62 static struct bus_type gpio_bus_type = {
  63         .name = "gpio",
  64 };
  65 
  66 /*
  67  * Number of GPIOs to use for the fast path in set array
  68  */
  69 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
  70 
  71 /* gpio_lock prevents conflicts during gpio_desc[] table updates.
  72  * While any GPIO is requested, its gpio_chip is not removable;
  73  * each GPIO's "requested" flag serves as a lock and refcount.
  74  */
  75 DEFINE_SPINLOCK(gpio_lock);
  76 
  77 static DEFINE_MUTEX(gpio_lookup_lock);
  78 static LIST_HEAD(gpio_lookup_list);
  79 LIST_HEAD(gpio_devices);
  80 
  81 static DEFINE_MUTEX(gpio_machine_hogs_mutex);
  82 static LIST_HEAD(gpio_machine_hogs);
  83 
  84 static void gpiochip_free_hogs(struct gpio_chip *chip);
  85 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
  86                                 struct lock_class_key *lock_key,
  87                                 struct lock_class_key *request_key);
  88 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
  89 static int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip);
  90 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
  91 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
  92 
  93 static bool gpiolib_initialized;
  94 
  95 static inline void desc_set_label(struct gpio_desc *d, const char *label)
  96 {
  97         d->label = label;
  98 }
  99 
 100 /**
 101  * gpio_to_desc - Convert a GPIO number to its descriptor
 102  * @gpio: global GPIO number
 103  *
 104  * Returns:
 105  * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
 106  * with the given number exists in the system.
 107  */
 108 struct gpio_desc *gpio_to_desc(unsigned gpio)
 109 {
 110         struct gpio_device *gdev;
 111         unsigned long flags;
 112 
 113         spin_lock_irqsave(&gpio_lock, flags);
 114 
 115         list_for_each_entry(gdev, &gpio_devices, list) {
 116                 if (gdev->base <= gpio &&
 117                     gdev->base + gdev->ngpio > gpio) {
 118                         spin_unlock_irqrestore(&gpio_lock, flags);
 119                         return &gdev->descs[gpio - gdev->base];
 120                 }
 121         }
 122 
 123         spin_unlock_irqrestore(&gpio_lock, flags);
 124 
 125         if (!gpio_is_valid(gpio))
 126                 WARN(1, "invalid GPIO %d\n", gpio);
 127 
 128         return NULL;
 129 }
 130 EXPORT_SYMBOL_GPL(gpio_to_desc);
 131 
 132 /**
 133  * gpiochip_get_desc - get the GPIO descriptor corresponding to the given
 134  *                     hardware number for this chip
 135  * @chip: GPIO chip
 136  * @hwnum: hardware number of the GPIO for this chip
 137  *
 138  * Returns:
 139  * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
 140  * in the given chip for the specified hardware number.
 141  */
 142 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
 143                                     u16 hwnum)
 144 {
 145         struct gpio_device *gdev = chip->gpiodev;
 146 
 147         if (hwnum >= gdev->ngpio)
 148                 return ERR_PTR(-EINVAL);
 149 
 150         return &gdev->descs[hwnum];
 151 }
 152 
 153 /**
 154  * desc_to_gpio - convert a GPIO descriptor to the integer namespace
 155  * @desc: GPIO descriptor
 156  *
 157  * This should disappear in the future but is needed since we still
 158  * use GPIO numbers for error messages and sysfs nodes.
 159  *
 160  * Returns:
 161  * The global GPIO number for the GPIO specified by its descriptor.
 162  */
 163 int desc_to_gpio(const struct gpio_desc *desc)
 164 {
 165         return desc->gdev->base + (desc - &desc->gdev->descs[0]);
 166 }
 167 EXPORT_SYMBOL_GPL(desc_to_gpio);
 168 
 169 
 170 /**
 171  * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
 172  * @desc:       descriptor to return the chip of
 173  */
 174 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 175 {
 176         if (!desc || !desc->gdev)
 177                 return NULL;
 178         return desc->gdev->chip;
 179 }
 180 EXPORT_SYMBOL_GPL(gpiod_to_chip);
 181 
 182 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */
 183 static int gpiochip_find_base(int ngpio)
 184 {
 185         struct gpio_device *gdev;
 186         int base = ARCH_NR_GPIOS - ngpio;
 187 
 188         list_for_each_entry_reverse(gdev, &gpio_devices, list) {
 189                 /* found a free space? */
 190                 if (gdev->base + gdev->ngpio <= base)
 191                         break;
 192                 else
 193                         /* nope, check the space right before the chip */
 194                         base = gdev->base - ngpio;
 195         }
 196 
 197         if (gpio_is_valid(base)) {
 198                 pr_debug("%s: found new base at %d\n", __func__, base);
 199                 return base;
 200         } else {
 201                 pr_err("%s: cannot find free range\n", __func__);
 202                 return -ENOSPC;
 203         }
 204 }
 205 
 206 /**
 207  * gpiod_get_direction - return the current direction of a GPIO
 208  * @desc:       GPIO to get the direction of
 209  *
 210  * Returns 0 for output, 1 for input, or an error code in case of error.
 211  *
 212  * This function may sleep if gpiod_cansleep() is true.
 213  */
 214 int gpiod_get_direction(struct gpio_desc *desc)
 215 {
 216         struct gpio_chip *chip;
 217         unsigned offset;
 218         int ret;
 219 
 220         chip = gpiod_to_chip(desc);
 221         offset = gpio_chip_hwgpio(desc);
 222 
 223         /*
 224          * Open drain emulation using input mode may incorrectly report
 225          * input here, fix that up.
 226          */
 227         if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) &&
 228             test_bit(FLAG_IS_OUT, &desc->flags))
 229                 return 0;
 230 
 231         if (!chip->get_direction)
 232                 return -ENOTSUPP;
 233 
 234         ret = chip->get_direction(chip, offset);
 235         if (ret > 0) {
 236                 /* GPIOF_DIR_IN, or other positive */
 237                 ret = 1;
 238                 clear_bit(FLAG_IS_OUT, &desc->flags);
 239         }
 240         if (ret == 0) {
 241                 /* GPIOF_DIR_OUT */
 242                 set_bit(FLAG_IS_OUT, &desc->flags);
 243         }
 244         return ret;
 245 }
 246 EXPORT_SYMBOL_GPL(gpiod_get_direction);
 247 
 248 /*
 249  * Add a new chip to the global chips list, keeping the list of chips sorted
 250  * by range(means [base, base + ngpio - 1]) order.
 251  *
 252  * Return -EBUSY if the new chip overlaps with some other chip's integer
 253  * space.
 254  */
 255 static int gpiodev_add_to_list(struct gpio_device *gdev)
 256 {
 257         struct gpio_device *prev, *next;
 258 
 259         if (list_empty(&gpio_devices)) {
 260                 /* initial entry in list */
 261                 list_add_tail(&gdev->list, &gpio_devices);
 262                 return 0;
 263         }
 264 
 265         next = list_entry(gpio_devices.next, struct gpio_device, list);
 266         if (gdev->base + gdev->ngpio <= next->base) {
 267                 /* add before first entry */
 268                 list_add(&gdev->list, &gpio_devices);
 269                 return 0;
 270         }
 271 
 272         prev = list_entry(gpio_devices.prev, struct gpio_device, list);
 273         if (prev->base + prev->ngpio <= gdev->base) {
 274                 /* add behind last entry */
 275                 list_add_tail(&gdev->list, &gpio_devices);
 276                 return 0;
 277         }
 278 
 279         list_for_each_entry_safe(prev, next, &gpio_devices, list) {
 280                 /* at the end of the list */
 281                 if (&next->list == &gpio_devices)
 282                         break;
 283 
 284                 /* add between prev and next */
 285                 if (prev->base + prev->ngpio <= gdev->base
 286                                 && gdev->base + gdev->ngpio <= next->base) {
 287                         list_add(&gdev->list, &prev->list);
 288                         return 0;
 289                 }
 290         }
 291 
 292         dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
 293         return -EBUSY;
 294 }
 295 
 296 /*
 297  * Convert a GPIO name to its descriptor
 298  */
 299 static struct gpio_desc *gpio_name_to_desc(const char * const name)
 300 {
 301         struct gpio_device *gdev;
 302         unsigned long flags;
 303 
 304         spin_lock_irqsave(&gpio_lock, flags);
 305 
 306         list_for_each_entry(gdev, &gpio_devices, list) {
 307                 int i;
 308 
 309                 for (i = 0; i != gdev->ngpio; ++i) {
 310                         struct gpio_desc *desc = &gdev->descs[i];
 311 
 312                         if (!desc->name || !name)
 313                                 continue;
 314 
 315                         if (!strcmp(desc->name, name)) {
 316                                 spin_unlock_irqrestore(&gpio_lock, flags);
 317                                 return desc;
 318                         }
 319                 }
 320         }
 321 
 322         spin_unlock_irqrestore(&gpio_lock, flags);
 323 
 324         return NULL;
 325 }
 326 
 327 /*
 328  * Takes the names from gc->names and checks if they are all unique. If they
 329  * are, they are assigned to their gpio descriptors.
 330  *
 331  * Warning if one of the names is already used for a different GPIO.
 332  */
 333 static int gpiochip_set_desc_names(struct gpio_chip *gc)
 334 {
 335         struct gpio_device *gdev = gc->gpiodev;
 336         int i;
 337 
 338         if (!gc->names)
 339                 return 0;
 340 
 341         /* First check all names if they are unique */
 342         for (i = 0; i != gc->ngpio; ++i) {
 343                 struct gpio_desc *gpio;
 344 
 345                 gpio = gpio_name_to_desc(gc->names[i]);
 346                 if (gpio)
 347                         dev_warn(&gdev->dev,
 348                                  "Detected name collision for GPIO name '%s'\n",
 349                                  gc->names[i]);
 350         }
 351 
 352         /* Then add all names to the GPIO descriptors */
 353         for (i = 0; i != gc->ngpio; ++i)
 354                 gdev->descs[i].name = gc->names[i];
 355 
 356         return 0;
 357 }
 358 
 359 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip)
 360 {
 361         unsigned long *p;
 362 
 363         p = bitmap_alloc(chip->ngpio, GFP_KERNEL);
 364         if (!p)
 365                 return NULL;
 366 
 367         /* Assume by default all GPIOs are valid */
 368         bitmap_fill(p, chip->ngpio);
 369 
 370         return p;
 371 }
 372 
 373 static int gpiochip_alloc_valid_mask(struct gpio_chip *gc)
 374 {
 375         if (!(of_gpio_need_valid_mask(gc) || gc->init_valid_mask))
 376                 return 0;
 377 
 378         gc->valid_mask = gpiochip_allocate_mask(gc);
 379         if (!gc->valid_mask)
 380                 return -ENOMEM;
 381 
 382         return 0;
 383 }
 384 
 385 static int gpiochip_init_valid_mask(struct gpio_chip *gc)
 386 {
 387         if (gc->init_valid_mask)
 388                 return gc->init_valid_mask(gc,
 389                                            gc->valid_mask,
 390                                            gc->ngpio);
 391 
 392         return 0;
 393 }
 394 
 395 static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip)
 396 {
 397         bitmap_free(gpiochip->valid_mask);
 398         gpiochip->valid_mask = NULL;
 399 }
 400 
 401 bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip,
 402                                 unsigned int offset)
 403 {
 404         /* No mask means all valid */
 405         if (likely(!gpiochip->valid_mask))
 406                 return true;
 407         return test_bit(offset, gpiochip->valid_mask);
 408 }
 409 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
 410 
 411 /*
 412  * GPIO line handle management
 413  */
 414 
 415 /**
 416  * struct linehandle_state - contains the state of a userspace handle
 417  * @gdev: the GPIO device the handle pertains to
 418  * @label: consumer label used to tag descriptors
 419  * @descs: the GPIO descriptors held by this handle
 420  * @numdescs: the number of descriptors held in the descs array
 421  */
 422 struct linehandle_state {
 423         struct gpio_device *gdev;
 424         const char *label;
 425         struct gpio_desc *descs[GPIOHANDLES_MAX];
 426         u32 numdescs;
 427 };
 428 
 429 #define GPIOHANDLE_REQUEST_VALID_FLAGS \
 430         (GPIOHANDLE_REQUEST_INPUT | \
 431         GPIOHANDLE_REQUEST_OUTPUT | \
 432         GPIOHANDLE_REQUEST_ACTIVE_LOW | \
 433         GPIOHANDLE_REQUEST_OPEN_DRAIN | \
 434         GPIOHANDLE_REQUEST_OPEN_SOURCE)
 435 
 436 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
 437                              unsigned long arg)
 438 {
 439         struct linehandle_state *lh = filep->private_data;
 440         void __user *ip = (void __user *)arg;
 441         struct gpiohandle_data ghd;
 442         DECLARE_BITMAP(vals, GPIOHANDLES_MAX);
 443         int i;
 444 
 445         if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
 446                 /* NOTE: It's ok to read values of output lines. */
 447                 int ret = gpiod_get_array_value_complex(false,
 448                                                         true,
 449                                                         lh->numdescs,
 450                                                         lh->descs,
 451                                                         NULL,
 452                                                         vals);
 453                 if (ret)
 454                         return ret;
 455 
 456                 memset(&ghd, 0, sizeof(ghd));
 457                 for (i = 0; i < lh->numdescs; i++)
 458                         ghd.values[i] = test_bit(i, vals);
 459 
 460                 if (copy_to_user(ip, &ghd, sizeof(ghd)))
 461                         return -EFAULT;
 462 
 463                 return 0;
 464         } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
 465                 /*
 466                  * All line descriptors were created at once with the same
 467                  * flags so just check if the first one is really output.
 468                  */
 469                 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags))
 470                         return -EPERM;
 471 
 472                 if (copy_from_user(&ghd, ip, sizeof(ghd)))
 473                         return -EFAULT;
 474 
 475                 /* Clamp all values to [0,1] */
 476                 for (i = 0; i < lh->numdescs; i++)
 477                         __assign_bit(i, vals, ghd.values[i]);
 478 
 479                 /* Reuse the array setting function */
 480                 return gpiod_set_array_value_complex(false,
 481                                               true,
 482                                               lh->numdescs,
 483                                               lh->descs,
 484                                               NULL,
 485                                               vals);
 486         }
 487         return -EINVAL;
 488 }
 489 
 490 #ifdef CONFIG_COMPAT
 491 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
 492                              unsigned long arg)
 493 {
 494         return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
 495 }
 496 #endif
 497 
 498 static int linehandle_release(struct inode *inode, struct file *filep)
 499 {
 500         struct linehandle_state *lh = filep->private_data;
 501         struct gpio_device *gdev = lh->gdev;
 502         int i;
 503 
 504         for (i = 0; i < lh->numdescs; i++)
 505                 gpiod_free(lh->descs[i]);
 506         kfree(lh->label);
 507         kfree(lh);
 508         put_device(&gdev->dev);
 509         return 0;
 510 }
 511 
 512 static const struct file_operations linehandle_fileops = {
 513         .release = linehandle_release,
 514         .owner = THIS_MODULE,
 515         .llseek = noop_llseek,
 516         .unlocked_ioctl = linehandle_ioctl,
 517 #ifdef CONFIG_COMPAT
 518         .compat_ioctl = linehandle_ioctl_compat,
 519 #endif
 520 };
 521 
 522 static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 523 {
 524         struct gpiohandle_request handlereq;
 525         struct linehandle_state *lh;
 526         struct file *file;
 527         int fd, i, count = 0, ret;
 528         u32 lflags;
 529 
 530         if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
 531                 return -EFAULT;
 532         if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
 533                 return -EINVAL;
 534 
 535         lflags = handlereq.flags;
 536 
 537         /* Return an error if an unknown flag is set */
 538         if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
 539                 return -EINVAL;
 540 
 541         /*
 542          * Do not allow both INPUT & OUTPUT flags to be set as they are
 543          * contradictory.
 544          */
 545         if ((lflags & GPIOHANDLE_REQUEST_INPUT) &&
 546             (lflags & GPIOHANDLE_REQUEST_OUTPUT))
 547                 return -EINVAL;
 548 
 549         /*
 550          * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
 551          * the hardware actually supports enabling both at the same time the
 552          * electrical result would be disastrous.
 553          */
 554         if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
 555             (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
 556                 return -EINVAL;
 557 
 558         /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
 559         if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
 560             ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
 561              (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
 562                 return -EINVAL;
 563 
 564         lh = kzalloc(sizeof(*lh), GFP_KERNEL);
 565         if (!lh)
 566                 return -ENOMEM;
 567         lh->gdev = gdev;
 568         get_device(&gdev->dev);
 569 
 570         /* Make sure this is terminated */
 571         handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
 572         if (strlen(handlereq.consumer_label)) {
 573                 lh->label = kstrdup(handlereq.consumer_label,
 574                                     GFP_KERNEL);
 575                 if (!lh->label) {
 576                         ret = -ENOMEM;
 577                         goto out_free_lh;
 578                 }
 579         }
 580 
 581         /* Request each GPIO */
 582         for (i = 0; i < handlereq.lines; i++) {
 583                 u32 offset = handlereq.lineoffsets[i];
 584                 struct gpio_desc *desc;
 585 
 586                 if (offset >= gdev->ngpio) {
 587                         ret = -EINVAL;
 588                         goto out_free_descs;
 589                 }
 590 
 591                 desc = &gdev->descs[offset];
 592                 ret = gpiod_request(desc, lh->label);
 593                 if (ret)
 594                         goto out_free_descs;
 595                 lh->descs[i] = desc;
 596                 count = i + 1;
 597 
 598                 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
 599                         set_bit(FLAG_ACTIVE_LOW, &desc->flags);
 600                 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
 601                         set_bit(FLAG_OPEN_DRAIN, &desc->flags);
 602                 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
 603                         set_bit(FLAG_OPEN_SOURCE, &desc->flags);
 604 
 605                 ret = gpiod_set_transitory(desc, false);
 606                 if (ret < 0)
 607                         goto out_free_descs;
 608 
 609                 /*
 610                  * Lines have to be requested explicitly for input
 611                  * or output, else the line will be treated "as is".
 612                  */
 613                 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
 614                         int val = !!handlereq.default_values[i];
 615 
 616                         ret = gpiod_direction_output(desc, val);
 617                         if (ret)
 618                                 goto out_free_descs;
 619                 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
 620                         ret = gpiod_direction_input(desc);
 621                         if (ret)
 622                                 goto out_free_descs;
 623                 }
 624                 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
 625                         offset);
 626         }
 627         /* Let i point at the last handle */
 628         i--;
 629         lh->numdescs = handlereq.lines;
 630 
 631         fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
 632         if (fd < 0) {
 633                 ret = fd;
 634                 goto out_free_descs;
 635         }
 636 
 637         file = anon_inode_getfile("gpio-linehandle",
 638                                   &linehandle_fileops,
 639                                   lh,
 640                                   O_RDONLY | O_CLOEXEC);
 641         if (IS_ERR(file)) {
 642                 ret = PTR_ERR(file);
 643                 goto out_put_unused_fd;
 644         }
 645 
 646         handlereq.fd = fd;
 647         if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
 648                 /*
 649                  * fput() will trigger the release() callback, so do not go onto
 650                  * the regular error cleanup path here.
 651                  */
 652                 fput(file);
 653                 put_unused_fd(fd);
 654                 return -EFAULT;
 655         }
 656 
 657         fd_install(fd, file);
 658 
 659         dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
 660                 lh->numdescs);
 661 
 662         return 0;
 663 
 664 out_put_unused_fd:
 665         put_unused_fd(fd);
 666 out_free_descs:
 667         for (i = 0; i < count; i++)
 668                 gpiod_free(lh->descs[i]);
 669         kfree(lh->label);
 670 out_free_lh:
 671         kfree(lh);
 672         put_device(&gdev->dev);
 673         return ret;
 674 }
 675 
 676 /*
 677  * GPIO line event management
 678  */
 679 
 680 /**
 681  * struct lineevent_state - contains the state of a userspace event
 682  * @gdev: the GPIO device the event pertains to
 683  * @label: consumer label used to tag descriptors
 684  * @desc: the GPIO descriptor held by this event
 685  * @eflags: the event flags this line was requested with
 686  * @irq: the interrupt that trigger in response to events on this GPIO
 687  * @wait: wait queue that handles blocking reads of events
 688  * @events: KFIFO for the GPIO events
 689  * @read_lock: mutex lock to protect reads from colliding with adding
 690  * new events to the FIFO
 691  * @timestamp: cache for the timestamp storing it between hardirq
 692  * and IRQ thread, used to bring the timestamp close to the actual
 693  * event
 694  */
 695 struct lineevent_state {
 696         struct gpio_device *gdev;
 697         const char *label;
 698         struct gpio_desc *desc;
 699         u32 eflags;
 700         int irq;
 701         wait_queue_head_t wait;
 702         DECLARE_KFIFO(events, struct gpioevent_data, 16);
 703         struct mutex read_lock;
 704         u64 timestamp;
 705 };
 706 
 707 #define GPIOEVENT_REQUEST_VALID_FLAGS \
 708         (GPIOEVENT_REQUEST_RISING_EDGE | \
 709         GPIOEVENT_REQUEST_FALLING_EDGE)
 710 
 711 static __poll_t lineevent_poll(struct file *filep,
 712                                    struct poll_table_struct *wait)
 713 {
 714         struct lineevent_state *le = filep->private_data;
 715         __poll_t events = 0;
 716 
 717         poll_wait(filep, &le->wait, wait);
 718 
 719         if (!kfifo_is_empty(&le->events))
 720                 events = EPOLLIN | EPOLLRDNORM;
 721 
 722         return events;
 723 }
 724 
 725 
 726 static ssize_t lineevent_read(struct file *filep,
 727                               char __user *buf,
 728                               size_t count,
 729                               loff_t *f_ps)
 730 {
 731         struct lineevent_state *le = filep->private_data;
 732         unsigned int copied;
 733         int ret;
 734 
 735         if (count < sizeof(struct gpioevent_data))
 736                 return -EINVAL;
 737 
 738         do {
 739                 if (kfifo_is_empty(&le->events)) {
 740                         if (filep->f_flags & O_NONBLOCK)
 741                                 return -EAGAIN;
 742 
 743                         ret = wait_event_interruptible(le->wait,
 744                                         !kfifo_is_empty(&le->events));
 745                         if (ret)
 746                                 return ret;
 747                 }
 748 
 749                 if (mutex_lock_interruptible(&le->read_lock))
 750                         return -ERESTARTSYS;
 751                 ret = kfifo_to_user(&le->events, buf, count, &copied);
 752                 mutex_unlock(&le->read_lock);
 753 
 754                 if (ret)
 755                         return ret;
 756 
 757                 /*
 758                  * If we couldn't read anything from the fifo (a different
 759                  * thread might have been faster) we either return -EAGAIN if
 760                  * the file descriptor is non-blocking, otherwise we go back to
 761                  * sleep and wait for more data to arrive.
 762                  */
 763                 if (copied == 0 && (filep->f_flags & O_NONBLOCK))
 764                         return -EAGAIN;
 765 
 766         } while (copied == 0);
 767 
 768         return copied;
 769 }
 770 
 771 static int lineevent_release(struct inode *inode, struct file *filep)
 772 {
 773         struct lineevent_state *le = filep->private_data;
 774         struct gpio_device *gdev = le->gdev;
 775 
 776         free_irq(le->irq, le);
 777         gpiod_free(le->desc);
 778         kfree(le->label);
 779         kfree(le);
 780         put_device(&gdev->dev);
 781         return 0;
 782 }
 783 
 784 static long lineevent_ioctl(struct file *filep, unsigned int cmd,
 785                             unsigned long arg)
 786 {
 787         struct lineevent_state *le = filep->private_data;
 788         void __user *ip = (void __user *)arg;
 789         struct gpiohandle_data ghd;
 790 
 791         /*
 792          * We can get the value for an event line but not set it,
 793          * because it is input by definition.
 794          */
 795         if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
 796                 int val;
 797 
 798                 memset(&ghd, 0, sizeof(ghd));
 799 
 800                 val = gpiod_get_value_cansleep(le->desc);
 801                 if (val < 0)
 802                         return val;
 803                 ghd.values[0] = val;
 804 
 805                 if (copy_to_user(ip, &ghd, sizeof(ghd)))
 806                         return -EFAULT;
 807 
 808                 return 0;
 809         }
 810         return -EINVAL;
 811 }
 812 
 813 #ifdef CONFIG_COMPAT
 814 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
 815                                    unsigned long arg)
 816 {
 817         return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
 818 }
 819 #endif
 820 
 821 static const struct file_operations lineevent_fileops = {
 822         .release = lineevent_release,
 823         .read = lineevent_read,
 824         .poll = lineevent_poll,
 825         .owner = THIS_MODULE,
 826         .llseek = noop_llseek,
 827         .unlocked_ioctl = lineevent_ioctl,
 828 #ifdef CONFIG_COMPAT
 829         .compat_ioctl = lineevent_ioctl_compat,
 830 #endif
 831 };
 832 
 833 static irqreturn_t lineevent_irq_thread(int irq, void *p)
 834 {
 835         struct lineevent_state *le = p;
 836         struct gpioevent_data ge;
 837         int ret;
 838 
 839         /* Do not leak kernel stack to userspace */
 840         memset(&ge, 0, sizeof(ge));
 841 
 842         /*
 843          * We may be running from a nested threaded interrupt in which case
 844          * we didn't get the timestamp from lineevent_irq_handler().
 845          */
 846         if (!le->timestamp)
 847                 ge.timestamp = ktime_get_real_ns();
 848         else
 849                 ge.timestamp = le->timestamp;
 850 
 851         if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
 852             && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
 853                 int level = gpiod_get_value_cansleep(le->desc);
 854                 if (level)
 855                         /* Emit low-to-high event */
 856                         ge.id = GPIOEVENT_EVENT_RISING_EDGE;
 857                 else
 858                         /* Emit high-to-low event */
 859                         ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
 860         } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) {
 861                 /* Emit low-to-high event */
 862                 ge.id = GPIOEVENT_EVENT_RISING_EDGE;
 863         } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
 864                 /* Emit high-to-low event */
 865                 ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
 866         } else {
 867                 return IRQ_NONE;
 868         }
 869 
 870         ret = kfifo_put(&le->events, ge);
 871         if (ret)
 872                 wake_up_poll(&le->wait, EPOLLIN);
 873 
 874         return IRQ_HANDLED;
 875 }
 876 
 877 static irqreturn_t lineevent_irq_handler(int irq, void *p)
 878 {
 879         struct lineevent_state *le = p;
 880 
 881         /*
 882          * Just store the timestamp in hardirq context so we get it as
 883          * close in time as possible to the actual event.
 884          */
 885         le->timestamp = ktime_get_real_ns();
 886 
 887         return IRQ_WAKE_THREAD;
 888 }
 889 
 890 static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 891 {
 892         struct gpioevent_request eventreq;
 893         struct lineevent_state *le;
 894         struct gpio_desc *desc;
 895         struct file *file;
 896         u32 offset;
 897         u32 lflags;
 898         u32 eflags;
 899         int fd;
 900         int ret;
 901         int irqflags = 0;
 902 
 903         if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
 904                 return -EFAULT;
 905 
 906         le = kzalloc(sizeof(*le), GFP_KERNEL);
 907         if (!le)
 908                 return -ENOMEM;
 909         le->gdev = gdev;
 910         get_device(&gdev->dev);
 911 
 912         /* Make sure this is terminated */
 913         eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
 914         if (strlen(eventreq.consumer_label)) {
 915                 le->label = kstrdup(eventreq.consumer_label,
 916                                     GFP_KERNEL);
 917                 if (!le->label) {
 918                         ret = -ENOMEM;
 919                         goto out_free_le;
 920                 }
 921         }
 922 
 923         offset = eventreq.lineoffset;
 924         lflags = eventreq.handleflags;
 925         eflags = eventreq.eventflags;
 926 
 927         if (offset >= gdev->ngpio) {
 928                 ret = -EINVAL;
 929                 goto out_free_label;
 930         }
 931 
 932         /* Return an error if a unknown flag is set */
 933         if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
 934             (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
 935                 ret = -EINVAL;
 936                 goto out_free_label;
 937         }
 938 
 939         /* This is just wrong: we don't look for events on output lines */
 940         if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
 941             (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
 942             (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
 943                 ret = -EINVAL;
 944                 goto out_free_label;
 945         }
 946 
 947         desc = &gdev->descs[offset];
 948         ret = gpiod_request(desc, le->label);
 949         if (ret)
 950                 goto out_free_label;
 951         le->desc = desc;
 952         le->eflags = eflags;
 953 
 954         if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
 955                 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
 956 
 957         ret = gpiod_direction_input(desc);
 958         if (ret)
 959                 goto out_free_desc;
 960 
 961         le->irq = gpiod_to_irq(desc);
 962         if (le->irq <= 0) {
 963                 ret = -ENODEV;
 964                 goto out_free_desc;
 965         }
 966 
 967         if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
 968                 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
 969                         IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
 970         if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
 971                 irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
 972                         IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
 973         irqflags |= IRQF_ONESHOT;
 974 
 975         INIT_KFIFO(le->events);
 976         init_waitqueue_head(&le->wait);
 977         mutex_init(&le->read_lock);
 978 
 979         /* Request a thread to read the events */
 980         ret = request_threaded_irq(le->irq,
 981                         lineevent_irq_handler,
 982                         lineevent_irq_thread,
 983                         irqflags,
 984                         le->label,
 985                         le);
 986         if (ret)
 987                 goto out_free_desc;
 988 
 989         fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
 990         if (fd < 0) {
 991                 ret = fd;
 992                 goto out_free_irq;
 993         }
 994 
 995         file = anon_inode_getfile("gpio-event",
 996                                   &lineevent_fileops,
 997                                   le,
 998                                   O_RDONLY | O_CLOEXEC);
 999         if (IS_ERR(file)) {
1000                 ret = PTR_ERR(file);
1001                 goto out_put_unused_fd;
1002         }
1003 
1004         eventreq.fd = fd;
1005         if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
1006                 /*
1007                  * fput() will trigger the release() callback, so do not go onto
1008                  * the regular error cleanup path here.
1009                  */
1010                 fput(file);
1011                 put_unused_fd(fd);
1012                 return -EFAULT;
1013         }
1014 
1015         fd_install(fd, file);
1016 
1017         return 0;
1018 
1019 out_put_unused_fd:
1020         put_unused_fd(fd);
1021 out_free_irq:
1022         free_irq(le->irq, le);
1023 out_free_desc:
1024         gpiod_free(le->desc);
1025 out_free_label:
1026         kfree(le->label);
1027 out_free_le:
1028         kfree(le);
1029         put_device(&gdev->dev);
1030         return ret;
1031 }
1032 
1033 /*
1034  * gpio_ioctl() - ioctl handler for the GPIO chardev
1035  */
1036 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1037 {
1038         struct gpio_device *gdev = filp->private_data;
1039         struct gpio_chip *chip = gdev->chip;
1040         void __user *ip = (void __user *)arg;
1041 
1042         /* We fail any subsequent ioctl():s when the chip is gone */
1043         if (!chip)
1044                 return -ENODEV;
1045 
1046         /* Fill in the struct and pass to userspace */
1047         if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
1048                 struct gpiochip_info chipinfo;
1049 
1050                 memset(&chipinfo, 0, sizeof(chipinfo));
1051 
1052                 strncpy(chipinfo.name, dev_name(&gdev->dev),
1053                         sizeof(chipinfo.name));
1054                 chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
1055                 strncpy(chipinfo.label, gdev->label,
1056                         sizeof(chipinfo.label));
1057                 chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
1058                 chipinfo.lines = gdev->ngpio;
1059                 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
1060                         return -EFAULT;
1061                 return 0;
1062         } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
1063                 struct gpioline_info lineinfo;
1064                 struct gpio_desc *desc;
1065 
1066                 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
1067                         return -EFAULT;
1068                 if (lineinfo.line_offset >= gdev->ngpio)
1069                         return -EINVAL;
1070 
1071                 desc = &gdev->descs[lineinfo.line_offset];
1072                 if (desc->name) {
1073                         strncpy(lineinfo.name, desc->name,
1074                                 sizeof(lineinfo.name));
1075                         lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
1076                 } else {
1077                         lineinfo.name[0] = '\0';
1078                 }
1079                 if (desc->label) {
1080                         strncpy(lineinfo.consumer, desc->label,
1081                                 sizeof(lineinfo.consumer));
1082                         lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
1083                 } else {
1084                         lineinfo.consumer[0] = '\0';
1085                 }
1086 
1087                 /*
1088                  * Userspace only need to know that the kernel is using
1089                  * this GPIO so it can't use it.
1090                  */
1091                 lineinfo.flags = 0;
1092                 if (test_bit(FLAG_REQUESTED, &desc->flags) ||
1093                     test_bit(FLAG_IS_HOGGED, &desc->flags) ||
1094                     test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
1095                     test_bit(FLAG_EXPORT, &desc->flags) ||
1096                     test_bit(FLAG_SYSFS, &desc->flags) ||
1097                     !pinctrl_gpio_can_use_line(chip->base + lineinfo.line_offset))
1098                         lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
1099                 if (test_bit(FLAG_IS_OUT, &desc->flags))
1100                         lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
1101                 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
1102                         lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
1103                 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
1104                         lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
1105                                            GPIOLINE_FLAG_IS_OUT);
1106                 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
1107                         lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
1108                                            GPIOLINE_FLAG_IS_OUT);
1109 
1110                 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
1111                         return -EFAULT;
1112                 return 0;
1113         } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
1114                 return linehandle_create(gdev, ip);
1115         } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
1116                 return lineevent_create(gdev, ip);
1117         }
1118         return -EINVAL;
1119 }
1120 
1121 #ifdef CONFIG_COMPAT
1122 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
1123                               unsigned long arg)
1124 {
1125         return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
1126 }
1127 #endif
1128 
1129 /**
1130  * gpio_chrdev_open() - open the chardev for ioctl operations
1131  * @inode: inode for this chardev
1132  * @filp: file struct for storing private data
1133  * Returns 0 on success
1134  */
1135 static int gpio_chrdev_open(struct inode *inode, struct file *filp)
1136 {
1137         struct gpio_device *gdev = container_of(inode->i_cdev,
1138                                               struct gpio_device, chrdev);
1139 
1140         /* Fail on open if the backing gpiochip is gone */
1141         if (!gdev->chip)
1142                 return -ENODEV;
1143         get_device(&gdev->dev);
1144         filp->private_data = gdev;
1145 
1146         return nonseekable_open(inode, filp);
1147 }
1148 
1149 /**
1150  * gpio_chrdev_release() - close chardev after ioctl operations
1151  * @inode: inode for this chardev
1152  * @filp: file struct for storing private data
1153  * Returns 0 on success
1154  */
1155 static int gpio_chrdev_release(struct inode *inode, struct file *filp)
1156 {
1157         struct gpio_device *gdev = container_of(inode->i_cdev,
1158                                               struct gpio_device, chrdev);
1159 
1160         put_device(&gdev->dev);
1161         return 0;
1162 }
1163 
1164 
1165 static const struct file_operations gpio_fileops = {
1166         .release = gpio_chrdev_release,
1167         .open = gpio_chrdev_open,
1168         .owner = THIS_MODULE,
1169         .llseek = no_llseek,
1170         .unlocked_ioctl = gpio_ioctl,
1171 #ifdef CONFIG_COMPAT
1172         .compat_ioctl = gpio_ioctl_compat,
1173 #endif
1174 };
1175 
1176 static void gpiodevice_release(struct device *dev)
1177 {
1178         struct gpio_device *gdev = dev_get_drvdata(dev);
1179 
1180         list_del(&gdev->list);
1181         ida_simple_remove(&gpio_ida, gdev->id);
1182         kfree_const(gdev->label);
1183         kfree(gdev->descs);
1184         kfree(gdev);
1185 }
1186 
1187 static int gpiochip_setup_dev(struct gpio_device *gdev)
1188 {
1189         int ret;
1190 
1191         cdev_init(&gdev->chrdev, &gpio_fileops);
1192         gdev->chrdev.owner = THIS_MODULE;
1193         gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
1194 
1195         ret = cdev_device_add(&gdev->chrdev, &gdev->dev);
1196         if (ret)
1197                 return ret;
1198 
1199         chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
1200                  MAJOR(gpio_devt), gdev->id);
1201 
1202         ret = gpiochip_sysfs_register(gdev);
1203         if (ret)
1204                 goto err_remove_device;
1205 
1206         /* From this point, the .release() function cleans up gpio_device */
1207         gdev->dev.release = gpiodevice_release;
1208         pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
1209                  __func__, gdev->base, gdev->base + gdev->ngpio - 1,
1210                  dev_name(&gdev->dev), gdev->chip->label ? : "generic");
1211 
1212         return 0;
1213 
1214 err_remove_device:
1215         cdev_device_del(&gdev->chrdev, &gdev->dev);
1216         return ret;
1217 }
1218 
1219 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog)
1220 {
1221         struct gpio_desc *desc;
1222         int rv;
1223 
1224         desc = gpiochip_get_desc(chip, hog->chip_hwnum);
1225         if (IS_ERR(desc)) {
1226                 pr_err("%s: unable to get GPIO desc: %ld\n",
1227                        __func__, PTR_ERR(desc));
1228                 return;
1229         }
1230 
1231         if (test_bit(FLAG_IS_HOGGED, &desc->flags))
1232                 return;
1233 
1234         rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
1235         if (rv)
1236                 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n",
1237                        __func__, chip->label, hog->chip_hwnum, rv);
1238 }
1239 
1240 static void machine_gpiochip_add(struct gpio_chip *chip)
1241 {
1242         struct gpiod_hog *hog;
1243 
1244         mutex_lock(&gpio_machine_hogs_mutex);
1245 
1246         list_for_each_entry(hog, &gpio_machine_hogs, list) {
1247                 if (!strcmp(chip->label, hog->chip_label))
1248                         gpiochip_machine_hog(chip, hog);
1249         }
1250 
1251         mutex_unlock(&gpio_machine_hogs_mutex);
1252 }
1253 
1254 static void gpiochip_setup_devs(void)
1255 {
1256         struct gpio_device *gdev;
1257         int ret;
1258 
1259         list_for_each_entry(gdev, &gpio_devices, list) {
1260                 ret = gpiochip_setup_dev(gdev);
1261                 if (ret)
1262                         pr_err("%s: Failed to initialize gpio device (%d)\n",
1263                                dev_name(&gdev->dev), ret);
1264         }
1265 }
1266 
1267 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
1268                                struct lock_class_key *lock_key,
1269                                struct lock_class_key *request_key)
1270 {
1271         unsigned long   flags;
1272         int             ret = 0;
1273         unsigned        i;
1274         int             base = chip->base;
1275         struct gpio_device *gdev;
1276 
1277         /*
1278          * First: allocate and populate the internal stat container, and
1279          * set up the struct device.
1280          */
1281         gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
1282         if (!gdev)
1283                 return -ENOMEM;
1284         gdev->dev.bus = &gpio_bus_type;
1285         gdev->chip = chip;
1286         chip->gpiodev = gdev;
1287         if (chip->parent) {
1288                 gdev->dev.parent = chip->parent;
1289                 gdev->dev.of_node = chip->parent->of_node;
1290         }
1291 
1292 #ifdef CONFIG_OF_GPIO
1293         /* If the gpiochip has an assigned OF node this takes precedence */
1294         if (chip->of_node)
1295                 gdev->dev.of_node = chip->of_node;
1296         else
1297                 chip->of_node = gdev->dev.of_node;
1298 #endif
1299 
1300         gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
1301         if (gdev->id < 0) {
1302                 ret = gdev->id;
1303                 goto err_free_gdev;
1304         }
1305         dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
1306         device_initialize(&gdev->dev);
1307         dev_set_drvdata(&gdev->dev, gdev);
1308         if (chip->parent && chip->parent->driver)
1309                 gdev->owner = chip->parent->driver->owner;
1310         else if (chip->owner)
1311                 /* TODO: remove chip->owner */
1312                 gdev->owner = chip->owner;
1313         else
1314                 gdev->owner = THIS_MODULE;
1315 
1316         gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
1317         if (!gdev->descs) {
1318                 ret = -ENOMEM;
1319                 goto err_free_ida;
1320         }
1321 
1322         if (chip->ngpio == 0) {
1323                 chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
1324                 ret = -EINVAL;
1325                 goto err_free_descs;
1326         }
1327 
1328         if (chip->ngpio > FASTPATH_NGPIO)
1329                 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n",
1330                 chip->ngpio, FASTPATH_NGPIO);
1331 
1332         gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
1333         if (!gdev->label) {
1334                 ret = -ENOMEM;
1335                 goto err_free_descs;
1336         }
1337 
1338         gdev->ngpio = chip->ngpio;
1339         gdev->data = data;
1340 
1341         spin_lock_irqsave(&gpio_lock, flags);
1342 
1343         /*
1344          * TODO: this allocates a Linux GPIO number base in the global
1345          * GPIO numberspace for this chip. In the long run we want to
1346          * get *rid* of this numberspace and use only descriptors, but
1347          * it may be a pipe dream. It will not happen before we get rid
1348          * of the sysfs interface anyways.
1349          */
1350         if (base < 0) {
1351                 base = gpiochip_find_base(chip->ngpio);
1352                 if (base < 0) {
1353                         ret = base;
1354                         spin_unlock_irqrestore(&gpio_lock, flags);
1355                         goto err_free_label;
1356                 }
1357                 /*
1358                  * TODO: it should not be necessary to reflect the assigned
1359                  * base outside of the GPIO subsystem. Go over drivers and
1360                  * see if anyone makes use of this, else drop this and assign
1361                  * a poison instead.
1362                  */
1363                 chip->base = base;
1364         }
1365         gdev->base = base;
1366 
1367         ret = gpiodev_add_to_list(gdev);
1368         if (ret) {
1369                 spin_unlock_irqrestore(&gpio_lock, flags);
1370                 goto err_free_label;
1371         }
1372 
1373         spin_unlock_irqrestore(&gpio_lock, flags);
1374 
1375         for (i = 0; i < chip->ngpio; i++)
1376                 gdev->descs[i].gdev = gdev;
1377 
1378 #ifdef CONFIG_PINCTRL
1379         INIT_LIST_HEAD(&gdev->pin_ranges);
1380 #endif
1381 
1382         ret = gpiochip_set_desc_names(chip);
1383         if (ret)
1384                 goto err_remove_from_list;
1385 
1386         ret = gpiochip_alloc_valid_mask(chip);
1387         if (ret)
1388                 goto err_remove_from_list;
1389 
1390         ret = of_gpiochip_add(chip);
1391         if (ret)
1392                 goto err_free_gpiochip_mask;
1393 
1394         ret = gpiochip_init_valid_mask(chip);
1395         if (ret)
1396                 goto err_remove_of_chip;
1397 
1398         for (i = 0; i < chip->ngpio; i++) {
1399                 struct gpio_desc *desc = &gdev->descs[i];
1400 
1401                 if (chip->get_direction && gpiochip_line_is_valid(chip, i)) {
1402                         if (!chip->get_direction(chip, i))
1403                                 set_bit(FLAG_IS_OUT, &desc->flags);
1404                         else
1405                                 clear_bit(FLAG_IS_OUT, &desc->flags);
1406                 } else {
1407                         if (!chip->direction_input)
1408                                 set_bit(FLAG_IS_OUT, &desc->flags);
1409                         else
1410                                 clear_bit(FLAG_IS_OUT, &desc->flags);
1411                 }
1412         }
1413 
1414         acpi_gpiochip_add(chip);
1415 
1416         machine_gpiochip_add(chip);
1417 
1418         ret = gpiochip_irqchip_init_hw(chip);
1419         if (ret)
1420                 goto err_remove_acpi_chip;
1421 
1422         ret = gpiochip_irqchip_init_valid_mask(chip);
1423         if (ret)
1424                 goto err_remove_acpi_chip;
1425 
1426         ret = gpiochip_add_irqchip(chip, lock_key, request_key);
1427         if (ret)
1428                 goto err_remove_irqchip_mask;
1429 
1430         /*
1431          * By first adding the chardev, and then adding the device,
1432          * we get a device node entry in sysfs under
1433          * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
1434          * coldplug of device nodes and other udev business.
1435          * We can do this only if gpiolib has been initialized.
1436          * Otherwise, defer until later.
1437          */
1438         if (gpiolib_initialized) {
1439                 ret = gpiochip_setup_dev(gdev);
1440                 if (ret)
1441                         goto err_remove_irqchip;
1442         }
1443         return 0;
1444 
1445 err_remove_irqchip:
1446         gpiochip_irqchip_remove(chip);
1447 err_remove_irqchip_mask:
1448         gpiochip_irqchip_free_valid_mask(chip);
1449 err_remove_acpi_chip:
1450         acpi_gpiochip_remove(chip);
1451 err_remove_of_chip:
1452         gpiochip_free_hogs(chip);
1453         of_gpiochip_remove(chip);
1454 err_free_gpiochip_mask:
1455         gpiochip_remove_pin_ranges(chip);
1456         gpiochip_free_valid_mask(chip);
1457 err_remove_from_list:
1458         spin_lock_irqsave(&gpio_lock, flags);
1459         list_del(&gdev->list);
1460         spin_unlock_irqrestore(&gpio_lock, flags);
1461 err_free_label:
1462         kfree_const(gdev->label);
1463 err_free_descs:
1464         kfree(gdev->descs);
1465 err_free_ida:
1466         ida_simple_remove(&gpio_ida, gdev->id);
1467 err_free_gdev:
1468         /* failures here can mean systems won't boot... */
1469         pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
1470                gdev->base, gdev->base + gdev->ngpio - 1,
1471                chip->label ? : "generic", ret);
1472         kfree(gdev);
1473         return ret;
1474 }
1475 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
1476 
1477 /**
1478  * gpiochip_get_data() - get per-subdriver data for the chip
1479  * @chip: GPIO chip
1480  *
1481  * Returns:
1482  * The per-subdriver data for the chip.
1483  */
1484 void *gpiochip_get_data(struct gpio_chip *chip)
1485 {
1486         return chip->gpiodev->data;
1487 }
1488 EXPORT_SYMBOL_GPL(gpiochip_get_data);
1489 
1490 /**
1491  * gpiochip_remove() - unregister a gpio_chip
1492  * @chip: the chip to unregister
1493  *
1494  * A gpio_chip with any GPIOs still requested may not be removed.
1495  */
1496 void gpiochip_remove(struct gpio_chip *chip)
1497 {
1498         struct gpio_device *gdev = chip->gpiodev;
1499         struct gpio_desc *desc;
1500         unsigned long   flags;
1501         unsigned        i;
1502         bool            requested = false;
1503 
1504         /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
1505         gpiochip_sysfs_unregister(gdev);
1506         gpiochip_free_hogs(chip);
1507         /* Numb the device, cancelling all outstanding operations */
1508         gdev->chip = NULL;
1509         gpiochip_irqchip_remove(chip);
1510         acpi_gpiochip_remove(chip);
1511         of_gpiochip_remove(chip);
1512         gpiochip_remove_pin_ranges(chip);
1513         gpiochip_free_valid_mask(chip);
1514         /*
1515          * We accept no more calls into the driver from this point, so
1516          * NULL the driver data pointer
1517          */
1518         gdev->data = NULL;
1519 
1520         spin_lock_irqsave(&gpio_lock, flags);
1521         for (i = 0; i < gdev->ngpio; i++) {
1522                 desc = &gdev->descs[i];
1523                 if (test_bit(FLAG_REQUESTED, &desc->flags))
1524                         requested = true;
1525         }
1526         spin_unlock_irqrestore(&gpio_lock, flags);
1527 
1528         if (requested)
1529                 dev_crit(&gdev->dev,
1530                          "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
1531 
1532         /*
1533          * The gpiochip side puts its use of the device to rest here:
1534          * if there are no userspace clients, the chardev and device will
1535          * be removed, else it will be dangling until the last user is
1536          * gone.
1537          */
1538         cdev_device_del(&gdev->chrdev, &gdev->dev);
1539         put_device(&gdev->dev);
1540 }
1541 EXPORT_SYMBOL_GPL(gpiochip_remove);
1542 
1543 static void devm_gpio_chip_release(struct device *dev, void *res)
1544 {
1545         struct gpio_chip *chip = *(struct gpio_chip **)res;
1546 
1547         gpiochip_remove(chip);
1548 }
1549 
1550 /**
1551  * devm_gpiochip_add_data() - Resource manager gpiochip_add_data()
1552  * @dev: pointer to the device that gpio_chip belongs to.
1553  * @chip: the chip to register, with chip->base initialized
1554  * @data: driver-private data associated with this chip
1555  *
1556  * Context: potentially before irqs will work
1557  *
1558  * The gpio chip automatically be released when the device is unbound.
1559  *
1560  * Returns:
1561  * A negative errno if the chip can't be registered, such as because the
1562  * chip->base is invalid or already associated with a different chip.
1563  * Otherwise it returns zero as a success code.
1564  */
1565 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
1566                            void *data)
1567 {
1568         struct gpio_chip **ptr;
1569         int ret;
1570 
1571         ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
1572                              GFP_KERNEL);
1573         if (!ptr)
1574                 return -ENOMEM;
1575 
1576         ret = gpiochip_add_data(chip, data);
1577         if (ret < 0) {
1578                 devres_free(ptr);
1579                 return ret;
1580         }
1581 
1582         *ptr = chip;
1583         devres_add(dev, ptr);
1584 
1585         return 0;
1586 }
1587 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
1588 
1589 /**
1590  * gpiochip_find() - iterator for locating a specific gpio_chip
1591  * @data: data to pass to match function
1592  * @match: Callback function to check gpio_chip
1593  *
1594  * Similar to bus_find_device.  It returns a reference to a gpio_chip as
1595  * determined by a user supplied @match callback.  The callback should return
1596  * 0 if the device doesn't match and non-zero if it does.  If the callback is
1597  * non-zero, this function will return to the caller and not iterate over any
1598  * more gpio_chips.
1599  */
1600 struct gpio_chip *gpiochip_find(void *data,
1601                                 int (*match)(struct gpio_chip *chip,
1602                                              void *data))
1603 {
1604         struct gpio_device *gdev;
1605         struct gpio_chip *chip = NULL;
1606         unsigned long flags;
1607 
1608         spin_lock_irqsave(&gpio_lock, flags);
1609         list_for_each_entry(gdev, &gpio_devices, list)
1610                 if (gdev->chip && match(gdev->chip, data)) {
1611                         chip = gdev->chip;
1612                         break;
1613                 }
1614 
1615         spin_unlock_irqrestore(&gpio_lock, flags);
1616 
1617         return chip;
1618 }
1619 EXPORT_SYMBOL_GPL(gpiochip_find);
1620 
1621 static int gpiochip_match_name(struct gpio_chip *chip, void *data)
1622 {
1623         const char *name = data;
1624 
1625         return !strcmp(chip->label, name);
1626 }
1627 
1628 static struct gpio_chip *find_chip_by_name(const char *name)
1629 {
1630         return gpiochip_find((void *)name, gpiochip_match_name);
1631 }
1632 
1633 #ifdef CONFIG_GPIOLIB_IRQCHIP
1634 
1635 /*
1636  * The following is irqchip helper code for gpiochips.
1637  */
1638 
1639 static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
1640 {
1641         struct gpio_irq_chip *girq = &gc->irq;
1642 
1643         if (!girq->init_hw)
1644                 return 0;
1645 
1646         return girq->init_hw(gc);
1647 }
1648 
1649 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
1650 {
1651         struct gpio_irq_chip *girq = &gc->irq;
1652 
1653         if (!girq->init_valid_mask)
1654                 return 0;
1655 
1656         girq->valid_mask = gpiochip_allocate_mask(gc);
1657         if (!girq->valid_mask)
1658                 return -ENOMEM;
1659 
1660         girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
1661 
1662         return 0;
1663 }
1664 
1665 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
1666 {
1667         bitmap_free(gpiochip->irq.valid_mask);
1668         gpiochip->irq.valid_mask = NULL;
1669 }
1670 
1671 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
1672                                 unsigned int offset)
1673 {
1674         if (!gpiochip_line_is_valid(gpiochip, offset))
1675                 return false;
1676         /* No mask means all valid */
1677         if (likely(!gpiochip->irq.valid_mask))
1678                 return true;
1679         return test_bit(offset, gpiochip->irq.valid_mask);
1680 }
1681 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid);
1682 
1683 /**
1684  * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
1685  * @gc: the gpiochip to set the irqchip chain to
1686  * @parent_irq: the irq number corresponding to the parent IRQ for this
1687  * chained irqchip
1688  * @parent_handler: the parent interrupt handler for the accumulated IRQ
1689  * coming out of the gpiochip. If the interrupt is nested rather than
1690  * cascaded, pass NULL in this handler argument
1691  */
1692 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gc,
1693                                           unsigned int parent_irq,
1694                                           irq_flow_handler_t parent_handler)
1695 {
1696         struct gpio_irq_chip *girq = &gc->irq;
1697         struct device *dev = &gc->gpiodev->dev;
1698 
1699         if (!girq->domain) {
1700                 chip_err(gc, "called %s before setting up irqchip\n",
1701                          __func__);
1702                 return;
1703         }
1704 
1705         if (parent_handler) {
1706                 if (gc->can_sleep) {
1707                         chip_err(gc,
1708                                  "you cannot have chained interrupts on a chip that may sleep\n");
1709                         return;
1710                 }
1711                 girq->parents = devm_kcalloc(dev, 1,
1712                                              sizeof(*girq->parents),
1713                                              GFP_KERNEL);
1714                 if (!girq->parents) {
1715                         chip_err(gc, "out of memory allocating parent IRQ\n");
1716                         return;
1717                 }
1718                 girq->parents[0] = parent_irq;
1719                 girq->num_parents = 1;
1720                 /*
1721                  * The parent irqchip is already using the chip_data for this
1722                  * irqchip, so our callbacks simply use the handler_data.
1723                  */
1724                 irq_set_chained_handler_and_data(parent_irq, parent_handler,
1725                                                  gc);
1726         }
1727 }
1728 
1729 /**
1730  * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
1731  * @gpiochip: the gpiochip to set the irqchip chain to
1732  * @irqchip: the irqchip to chain to the gpiochip
1733  * @parent_irq: the irq number corresponding to the parent IRQ for this
1734  * chained irqchip
1735  * @parent_handler: the parent interrupt handler for the accumulated IRQ
1736  * coming out of the gpiochip.
1737  */
1738 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
1739                                   struct irq_chip *irqchip,
1740                                   unsigned int parent_irq,
1741                                   irq_flow_handler_t parent_handler)
1742 {
1743         if (gpiochip->irq.threaded) {
1744                 chip_err(gpiochip, "tried to chain a threaded gpiochip\n");
1745                 return;
1746         }
1747 
1748         gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler);
1749 }
1750 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
1751 
1752 /**
1753  * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
1754  * @gpiochip: the gpiochip to set the irqchip nested handler to
1755  * @irqchip: the irqchip to nest to the gpiochip
1756  * @parent_irq: the irq number corresponding to the parent IRQ for this
1757  * nested irqchip
1758  */
1759 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
1760                                  struct irq_chip *irqchip,
1761                                  unsigned int parent_irq)
1762 {
1763         gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL);
1764 }
1765 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
1766 
1767 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
1768 
1769 /**
1770  * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
1771  * to a gpiochip
1772  * @gc: the gpiochip to set the irqchip hierarchical handler to
1773  * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
1774  * will then percolate up to the parent
1775  */
1776 static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
1777                                               struct irq_chip *irqchip)
1778 {
1779         /* DT will deal with mapping each IRQ as we go along */
1780         if (is_of_node(gc->irq.fwnode))
1781                 return;
1782 
1783         /*
1784          * This is for legacy and boardfile "irqchip" fwnodes: allocate
1785          * irqs upfront instead of dynamically since we don't have the
1786          * dynamic type of allocation that hardware description languages
1787          * provide. Once all GPIO drivers using board files are gone from
1788          * the kernel we can delete this code, but for a transitional period
1789          * it is necessary to keep this around.
1790          */
1791         if (is_fwnode_irqchip(gc->irq.fwnode)) {
1792                 int i;
1793                 int ret;
1794 
1795                 for (i = 0; i < gc->ngpio; i++) {
1796                         struct irq_fwspec fwspec;
1797                         unsigned int parent_hwirq;
1798                         unsigned int parent_type;
1799                         struct gpio_irq_chip *girq = &gc->irq;
1800 
1801                         /*
1802                          * We call the child to parent translation function
1803                          * only to check if the child IRQ is valid or not.
1804                          * Just pick the rising edge type here as that is what
1805                          * we likely need to support.
1806                          */
1807                         ret = girq->child_to_parent_hwirq(gc, i,
1808                                                           IRQ_TYPE_EDGE_RISING,
1809                                                           &parent_hwirq,
1810                                                           &parent_type);
1811                         if (ret) {
1812                                 chip_err(gc, "skip set-up on hwirq %d\n",
1813                                          i);
1814                                 continue;
1815                         }
1816 
1817                         fwspec.fwnode = gc->irq.fwnode;
1818                         /* This is the hwirq for the GPIO line side of things */
1819                         fwspec.param[0] = girq->child_offset_to_irq(gc, i);
1820                         /* Just pick something */
1821                         fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
1822                         fwspec.param_count = 2;
1823                         ret = __irq_domain_alloc_irqs(gc->irq.domain,
1824                                                       /* just pick something */
1825                                                       -1,
1826                                                       1,
1827                                                       NUMA_NO_NODE,
1828                                                       &fwspec,
1829                                                       false,
1830                                                       NULL);
1831                         if (ret < 0) {
1832                                 chip_err(gc,
1833                                          "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
1834                                          i, parent_hwirq,
1835                                          ret);
1836                         }
1837                 }
1838         }
1839 
1840         chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
1841 
1842         return;
1843 }
1844 
1845 static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
1846                                                    struct irq_fwspec *fwspec,
1847                                                    unsigned long *hwirq,
1848                                                    unsigned int *type)
1849 {
1850         /* We support standard DT translation */
1851         if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
1852                 return irq_domain_translate_twocell(d, fwspec, hwirq, type);
1853         }
1854 
1855         /* This is for board files and others not using DT */
1856         if (is_fwnode_irqchip(fwspec->fwnode)) {
1857                 int ret;
1858 
1859                 ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
1860                 if (ret)
1861                         return ret;
1862                 WARN_ON(*type == IRQ_TYPE_NONE);
1863                 return 0;
1864         }
1865         return -EINVAL;
1866 }
1867 
1868 static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
1869                                                unsigned int irq,
1870                                                unsigned int nr_irqs,
1871                                                void *data)
1872 {
1873         struct gpio_chip *gc = d->host_data;
1874         irq_hw_number_t hwirq;
1875         unsigned int type = IRQ_TYPE_NONE;
1876         struct irq_fwspec *fwspec = data;
1877         struct irq_fwspec parent_fwspec;
1878         unsigned int parent_hwirq;
1879         unsigned int parent_type;
1880         struct gpio_irq_chip *girq = &gc->irq;
1881         int ret;
1882 
1883         /*
1884          * The nr_irqs parameter is always one except for PCI multi-MSI
1885          * so this should not happen.
1886          */
1887         WARN_ON(nr_irqs != 1);
1888 
1889         ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
1890         if (ret)
1891                 return ret;
1892 
1893         chip_info(gc, "allocate IRQ %d, hwirq %lu\n", irq,  hwirq);
1894 
1895         ret = girq->child_to_parent_hwirq(gc, hwirq, type,
1896                                           &parent_hwirq, &parent_type);
1897         if (ret) {
1898                 chip_err(gc, "can't look up hwirq %lu\n", hwirq);
1899                 return ret;
1900         }
1901         chip_info(gc, "found parent hwirq %u\n", parent_hwirq);
1902 
1903         /*
1904          * We set handle_bad_irq because the .set_type() should
1905          * always be invoked and set the right type of handler.
1906          */
1907         irq_domain_set_info(d,
1908                             irq,
1909                             hwirq,
1910                             gc->irq.chip,
1911                             gc,
1912                             girq->handler,
1913                             NULL, NULL);
1914         irq_set_probe(irq);
1915 
1916         /*
1917          * Create a IRQ fwspec to send up to the parent irqdomain:
1918          * specify the hwirq we address on the parent and tie it
1919          * all together up the chain.
1920          */
1921         parent_fwspec.fwnode = d->parent->fwnode;
1922         /* This parent only handles asserted level IRQs */
1923         girq->populate_parent_fwspec(gc, &parent_fwspec, parent_hwirq,
1924                                      parent_type);
1925         chip_info(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
1926                   irq, parent_hwirq);
1927         irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
1928         ret = irq_domain_alloc_irqs_parent(d, irq, 1, &parent_fwspec);
1929         if (ret)
1930                 chip_err(gc,
1931                          "failed to allocate parent hwirq %d for hwirq %lu\n",
1932                          parent_hwirq, hwirq);
1933 
1934         return ret;
1935 }
1936 
1937 static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *chip,
1938                                                       unsigned int offset)
1939 {
1940         return offset;
1941 }
1942 
1943 static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
1944 {
1945         ops->activate = gpiochip_irq_domain_activate;
1946         ops->deactivate = gpiochip_irq_domain_deactivate;
1947         ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
1948         ops->free = irq_domain_free_irqs_common;
1949 
1950         /*
1951          * We only allow overriding the translate() function for
1952          * hierarchical chips, and this should only be done if the user
1953          * really need something other than 1:1 translation.
1954          */
1955         if (!ops->translate)
1956                 ops->translate = gpiochip_hierarchy_irq_domain_translate;
1957 }
1958 
1959 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
1960 {
1961         if (!gc->irq.child_to_parent_hwirq ||
1962             !gc->irq.fwnode) {
1963                 chip_err(gc, "missing irqdomain vital data\n");
1964                 return -EINVAL;
1965         }
1966 
1967         if (!gc->irq.child_offset_to_irq)
1968                 gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
1969 
1970         if (!gc->irq.populate_parent_fwspec)
1971                 gc->irq.populate_parent_fwspec =
1972                         gpiochip_populate_parent_fwspec_twocell;
1973 
1974         gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
1975 
1976         gc->irq.domain = irq_domain_create_hierarchy(
1977                 gc->irq.parent_domain,
1978                 0,
1979                 gc->ngpio,
1980                 gc->irq.fwnode,
1981                 &gc->irq.child_irq_domain_ops,
1982                 gc);
1983 
1984         if (!gc->irq.domain)
1985                 return -ENOMEM;
1986 
1987         gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
1988 
1989         return 0;
1990 }
1991 
1992 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
1993 {
1994         return !!gc->irq.parent_domain;
1995 }
1996 
1997 void gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *chip,
1998                                              struct irq_fwspec *fwspec,
1999                                              unsigned int parent_hwirq,
2000                                              unsigned int parent_type)
2001 {
2002         fwspec->param_count = 2;
2003         fwspec->param[0] = parent_hwirq;
2004         fwspec->param[1] = parent_type;
2005 }
2006 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
2007 
2008 void gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *chip,
2009                                               struct irq_fwspec *fwspec,
2010                                               unsigned int parent_hwirq,
2011                                               unsigned int parent_type)
2012 {
2013         fwspec->param_count = 4;
2014         fwspec->param[0] = 0;
2015         fwspec->param[1] = parent_hwirq;
2016         fwspec->param[2] = 0;
2017         fwspec->param[3] = parent_type;
2018 }
2019 EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
2020 
2021 #else
2022 
2023 static int gpiochip_hierarchy_add_domain(struct gpio_chip *gc)
2024 {
2025         return -EINVAL;
2026 }
2027 
2028 static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
2029 {
2030         return false;
2031 }
2032 
2033 #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
2034 
2035 /**
2036  * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
2037  * @d: the irqdomain used by this irqchip
2038  * @irq: the global irq number used by this GPIO irqchip irq
2039  * @hwirq: the local IRQ/GPIO line offset on this gpiochip
2040  *
2041  * This function will set up the mapping for a certain IRQ line on a
2042  * gpiochip by assigning the gpiochip as chip data, and using the irqchip
2043  * stored inside the gpiochip.
2044  */
2045 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
2046                      irq_hw_number_t hwirq)
2047 {
2048         struct gpio_chip *chip = d->host_data;
2049         int ret = 0;
2050 
2051         if (!gpiochip_irqchip_irq_valid(chip, hwirq))
2052                 return -ENXIO;
2053 
2054         irq_set_chip_data(irq, chip);
2055         /*
2056          * This lock class tells lockdep that GPIO irqs are in a different
2057          * category than their parents, so it won't report false recursion.
2058          */
2059         irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key);
2060         irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler);
2061         /* Chips that use nested thread handlers have them marked */
2062         if (chip->irq.threaded)
2063                 irq_set_nested_thread(irq, 1);
2064         irq_set_noprobe(irq);
2065 
2066         if (chip->irq.num_parents == 1)
2067                 ret = irq_set_parent(irq, chip->irq.parents[0]);
2068         else if (chip->irq.map)
2069                 ret = irq_set_parent(irq, chip->irq.map[hwirq]);
2070 
2071         if (ret < 0)
2072                 return ret;
2073 
2074         /*
2075          * No set-up of the hardware will happen if IRQ_TYPE_NONE
2076          * is passed as default type.
2077          */
2078         if (chip->irq.default_type != IRQ_TYPE_NONE)
2079                 irq_set_irq_type(irq, chip->irq.default_type);
2080 
2081         return 0;
2082 }
2083 EXPORT_SYMBOL_GPL(gpiochip_irq_map);
2084 
2085 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
2086 {
2087         struct gpio_chip *chip = d->host_data;
2088 
2089         if (chip->irq.threaded)
2090                 irq_set_nested_thread(irq, 0);
2091         irq_set_chip_and_handler(irq, NULL, NULL);
2092         irq_set_chip_data(irq, NULL);
2093 }
2094 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap);
2095 
2096 static const struct irq_domain_ops gpiochip_domain_ops = {
2097         .map    = gpiochip_irq_map,
2098         .unmap  = gpiochip_irq_unmap,
2099         /* Virtually all GPIO irqchips are twocell:ed */
2100         .xlate  = irq_domain_xlate_twocell,
2101 };
2102 
2103 /*
2104  * TODO: move these activate/deactivate in under the hierarchicial
2105  * irqchip implementation as static once SPMI and SSBI (all external
2106  * users) are phased over.
2107  */
2108 /**
2109  * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
2110  * @domain: The IRQ domain used by this IRQ chip
2111  * @data: Outermost irq_data associated with the IRQ
2112  * @reserve: If set, only reserve an interrupt vector instead of assigning one
2113  *
2114  * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
2115  * used as the activate function for the &struct irq_domain_ops. The host_data
2116  * for the IRQ domain must be the &struct gpio_chip.
2117  */
2118 int gpiochip_irq_domain_activate(struct irq_domain *domain,
2119                                  struct irq_data *data, bool reserve)
2120 {
2121         struct gpio_chip *chip = domain->host_data;
2122 
2123         return gpiochip_lock_as_irq(chip, data->hwirq);
2124 }
2125 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate);
2126 
2127 /**
2128  * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
2129  * @domain: The IRQ domain used by this IRQ chip
2130  * @data: Outermost irq_data associated with the IRQ
2131  *
2132  * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
2133  * be used as the deactivate function for the &struct irq_domain_ops. The
2134  * host_data for the IRQ domain must be the &struct gpio_chip.
2135  */
2136 void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
2137                                     struct irq_data *data)
2138 {
2139         struct gpio_chip *chip = domain->host_data;
2140 
2141         return gpiochip_unlock_as_irq(chip, data->hwirq);
2142 }
2143 EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate);
2144 
2145 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
2146 {
2147         struct irq_domain *domain = chip->irq.domain;
2148 
2149         if (!gpiochip_irqchip_irq_valid(chip, offset))
2150                 return -ENXIO;
2151 
2152 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
2153         if (irq_domain_is_hierarchy(domain)) {
2154                 struct irq_fwspec spec;
2155 
2156                 spec.fwnode = domain->fwnode;
2157                 spec.param_count = 2;
2158                 spec.param[0] = chip->irq.child_offset_to_irq(chip, offset);
2159                 spec.param[1] = IRQ_TYPE_NONE;
2160 
2161                 return irq_create_fwspec_mapping(&spec);
2162         }
2163 #endif
2164 
2165         return irq_create_mapping(domain, offset);
2166 }
2167 
2168 static int gpiochip_irq_reqres(struct irq_data *d)
2169 {
2170         struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2171 
2172         return gpiochip_reqres_irq(chip, d->hwirq);
2173 }
2174 
2175 static void gpiochip_irq_relres(struct irq_data *d)
2176 {
2177         struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2178 
2179         gpiochip_relres_irq(chip, d->hwirq);
2180 }
2181 
2182 static void gpiochip_irq_enable(struct irq_data *d)
2183 {
2184         struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2185 
2186         gpiochip_enable_irq(chip, d->hwirq);
2187         if (chip->irq.irq_enable)
2188                 chip->irq.irq_enable(d);
2189         else
2190                 chip->irq.chip->irq_unmask(d);
2191 }
2192 
2193 static void gpiochip_irq_disable(struct irq_data *d)
2194 {
2195         struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
2196 
2197         /*
2198          * Since we override .irq_disable() we need to mimic the
2199          * behaviour of __irq_disable() in irq/chip.c.
2200          * First call .irq_disable() if it exists, else mimic the
2201          * behaviour of mask_irq() which calls .irq_mask() if
2202          * it exists.
2203          */
2204         if (chip->irq.irq_disable)
2205                 chip->irq.irq_disable(d);
2206         else if (chip->irq.chip->irq_mask)
2207                 chip->irq.chip->irq_mask(d);
2208         gpiochip_disable_irq(chip, d->hwirq);
2209 }
2210 
2211 static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip)
2212 {
2213         struct irq_chip *irqchip = gpiochip->irq.chip;
2214 
2215         if (!irqchip->irq_request_resources &&
2216             !irqchip->irq_release_resources) {
2217                 irqchip->irq_request_resources = gpiochip_irq_reqres;
2218                 irqchip->irq_release_resources = gpiochip_irq_relres;
2219         }
2220         if (WARN_ON(gpiochip->irq.irq_enable))
2221                 return;
2222         /* Check if the irqchip already has this hook... */
2223         if (irqchip->irq_enable == gpiochip_irq_enable) {
2224                 /*
2225                  * ...and if so, give a gentle warning that this is bad
2226                  * practice.
2227                  */
2228                 chip_info(gpiochip,
2229                           "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
2230                 return;
2231         }
2232         gpiochip->irq.irq_enable = irqchip->irq_enable;
2233         gpiochip->irq.irq_disable = irqchip->irq_disable;
2234         irqchip->irq_enable = gpiochip_irq_enable;
2235         irqchip->irq_disable = gpiochip_irq_disable;
2236 }
2237 
2238 /**
2239  * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
2240  * @gpiochip: the GPIO chip to add the IRQ chip to
2241  * @lock_key: lockdep class for IRQ lock
2242  * @request_key: lockdep class for IRQ request
2243  */
2244 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2245                                 struct lock_class_key *lock_key,
2246                                 struct lock_class_key *request_key)
2247 {
2248         struct irq_chip *irqchip = gpiochip->irq.chip;
2249         const struct irq_domain_ops *ops = NULL;
2250         struct device_node *np;
2251         unsigned int type;
2252         unsigned int i;
2253 
2254         if (!irqchip)
2255                 return 0;
2256 
2257         if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {
2258                 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n");
2259                 return -EINVAL;
2260         }
2261 
2262         np = gpiochip->gpiodev->dev.of_node;
2263         type = gpiochip->irq.default_type;
2264 
2265         /*
2266          * Specifying a default trigger is a terrible idea if DT or ACPI is
2267          * used to configure the interrupts, as you may end up with
2268          * conflicting triggers. Tell the user, and reset to NONE.
2269          */
2270         if (WARN(np && type != IRQ_TYPE_NONE,
2271                  "%s: Ignoring %u default trigger\n", np->full_name, type))
2272                 type = IRQ_TYPE_NONE;
2273 
2274         if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2275                 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2276                                  "Ignoring %u default trigger\n", type);
2277                 type = IRQ_TYPE_NONE;
2278         }
2279 
2280         gpiochip->to_irq = gpiochip_to_irq;
2281         gpiochip->irq.default_type = type;
2282         gpiochip->irq.lock_key = lock_key;
2283         gpiochip->irq.request_key = request_key;
2284 
2285         /* If a parent irqdomain is provided, let's build a hierarchy */
2286         if (gpiochip_hierarchy_is_hierarchical(gpiochip)) {
2287                 int ret = gpiochip_hierarchy_add_domain(gpiochip);
2288                 if (ret)
2289                         return ret;
2290         } else {
2291                 /* Some drivers provide custom irqdomain ops */
2292                 if (gpiochip->irq.domain_ops)
2293                         ops = gpiochip->irq.domain_ops;
2294 
2295                 if (!ops)
2296                         ops = &gpiochip_domain_ops;
2297                 gpiochip->irq.domain = irq_domain_add_simple(np,
2298                         gpiochip->ngpio,
2299                         gpiochip->irq.first,
2300                         ops, gpiochip);
2301                 if (!gpiochip->irq.domain)
2302                         return -EINVAL;
2303         }
2304 
2305         if (gpiochip->irq.parent_handler) {
2306                 void *data = gpiochip->irq.parent_handler_data ?: gpiochip;
2307 
2308                 for (i = 0; i < gpiochip->irq.num_parents; i++) {
2309                         /*
2310                          * The parent IRQ chip is already using the chip_data
2311                          * for this IRQ chip, so our callbacks simply use the
2312                          * handler_data.
2313                          */
2314                         irq_set_chained_handler_and_data(gpiochip->irq.parents[i],
2315                                                          gpiochip->irq.parent_handler,
2316                                                          data);
2317                 }
2318         }
2319 
2320         gpiochip_set_irq_hooks(gpiochip);
2321 
2322         acpi_gpiochip_request_interrupts(gpiochip);
2323 
2324         return 0;
2325 }
2326 
2327 /**
2328  * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
2329  * @gpiochip: the gpiochip to remove the irqchip from
2330  *
2331  * This is called only from gpiochip_remove()
2332  */
2333 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
2334 {
2335         struct irq_chip *irqchip = gpiochip->irq.chip;
2336         unsigned int offset;
2337 
2338         acpi_gpiochip_free_interrupts(gpiochip);
2339 
2340         if (irqchip && gpiochip->irq.parent_handler) {
2341                 struct gpio_irq_chip *irq = &gpiochip->irq;
2342                 unsigned int i;
2343 
2344                 for (i = 0; i < irq->num_parents; i++)
2345                         irq_set_chained_handler_and_data(irq->parents[i],
2346                                                          NULL, NULL);
2347         }
2348 
2349         /* Remove all IRQ mappings and delete the domain */
2350         if (gpiochip->irq.domain) {
2351                 unsigned int irq;
2352 
2353                 for (offset = 0; offset < gpiochip->ngpio; offset++) {
2354                         if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
2355                                 continue;
2356 
2357                         irq = irq_find_mapping(gpiochip->irq.domain, offset);
2358                         irq_dispose_mapping(irq);
2359                 }
2360 
2361                 irq_domain_remove(gpiochip->irq.domain);
2362         }
2363 
2364         if (irqchip) {
2365                 if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
2366                         irqchip->irq_request_resources = NULL;
2367                         irqchip->irq_release_resources = NULL;
2368                 }
2369                 if (irqchip->irq_enable == gpiochip_irq_enable) {
2370                         irqchip->irq_enable = gpiochip->irq.irq_enable;
2371                         irqchip->irq_disable = gpiochip->irq.irq_disable;
2372                 }
2373         }
2374         gpiochip->irq.irq_enable = NULL;
2375         gpiochip->irq.irq_disable = NULL;
2376         gpiochip->irq.chip = NULL;
2377 
2378         gpiochip_irqchip_free_valid_mask(gpiochip);
2379 }
2380 
2381 /**
2382  * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
2383  * @gpiochip: the gpiochip to add the irqchip to
2384  * @irqchip: the irqchip to add to the gpiochip
2385  * @first_irq: if not dynamically assigned, the base (first) IRQ to
2386  * allocate gpiochip irqs from
2387  * @handler: the irq handler to use (often a predefined irq core function)
2388  * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
2389  * to have the core avoid setting up any default type in the hardware.
2390  * @threaded: whether this irqchip uses a nested thread handler
2391  * @lock_key: lockdep class for IRQ lock
2392  * @request_key: lockdep class for IRQ request
2393  *
2394  * This function closely associates a certain irqchip with a certain
2395  * gpiochip, providing an irq domain to translate the local IRQs to
2396  * global irqs in the gpiolib core, and making sure that the gpiochip
2397  * is passed as chip data to all related functions. Driver callbacks
2398  * need to use gpiochip_get_data() to get their local state containers back
2399  * from the gpiochip passed as chip data. An irqdomain will be stored
2400  * in the gpiochip that shall be used by the driver to handle IRQ number
2401  * translation. The gpiochip will need to be initialized and registered
2402  * before calling this function.
2403  *
2404  * This function will handle two cell:ed simple IRQs and assumes all
2405  * the pins on the gpiochip can generate a unique IRQ. Everything else
2406  * need to be open coded.
2407  */
2408 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
2409                              struct irq_chip *irqchip,
2410                              unsigned int first_irq,
2411                              irq_flow_handler_t handler,
2412                              unsigned int type,
2413                              bool threaded,
2414                              struct lock_class_key *lock_key,
2415                              struct lock_class_key *request_key)
2416 {
2417         struct device_node *of_node;
2418 
2419         if (!gpiochip || !irqchip)
2420                 return -EINVAL;
2421 
2422         if (!gpiochip->parent) {
2423                 pr_err("missing gpiochip .dev parent pointer\n");
2424                 return -EINVAL;
2425         }
2426         gpiochip->irq.threaded = threaded;
2427         of_node = gpiochip->parent->of_node;
2428 #ifdef CONFIG_OF_GPIO
2429         /*
2430          * If the gpiochip has an assigned OF node this takes precedence
2431          * FIXME: get rid of this and use gpiochip->parent->of_node
2432          * everywhere
2433          */
2434         if (gpiochip->of_node)
2435                 of_node = gpiochip->of_node;
2436 #endif
2437         /*
2438          * Specifying a default trigger is a terrible idea if DT or ACPI is
2439          * used to configure the interrupts, as you may end-up with
2440          * conflicting triggers. Tell the user, and reset to NONE.
2441          */
2442         if (WARN(of_node && type != IRQ_TYPE_NONE,
2443                  "%pOF: Ignoring %d default trigger\n", of_node, type))
2444                 type = IRQ_TYPE_NONE;
2445         if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
2446                 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
2447                                  "Ignoring %d default trigger\n", type);
2448                 type = IRQ_TYPE_NONE;
2449         }
2450 
2451         gpiochip->irq.chip = irqchip;
2452         gpiochip->irq.handler = handler;
2453         gpiochip->irq.default_type = type;
2454         gpiochip->to_irq = gpiochip_to_irq;
2455         gpiochip->irq.lock_key = lock_key;
2456         gpiochip->irq.request_key = request_key;
2457         gpiochip->irq.domain = irq_domain_add_simple(of_node,
2458                                         gpiochip->ngpio, first_irq,
2459                                         &gpiochip_domain_ops, gpiochip);
2460         if (!gpiochip->irq.domain) {
2461                 gpiochip->irq.chip = NULL;
2462                 return -EINVAL;
2463         }
2464 
2465         gpiochip_set_irq_hooks(gpiochip);
2466 
2467         acpi_gpiochip_request_interrupts(gpiochip);
2468 
2469         return 0;
2470 }
2471 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
2472 
2473 #else /* CONFIG_GPIOLIB_IRQCHIP */
2474 
2475 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
2476                                        struct lock_class_key *lock_key,
2477                                        struct lock_class_key *request_key)
2478 {
2479         return 0;
2480 }
2481 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
2482 
2483 static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip)
2484 {
2485         return 0;
2486 }
2487 
2488 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
2489 {
2490         return 0;
2491 }
2492 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
2493 { }
2494 
2495 #endif /* CONFIG_GPIOLIB_IRQCHIP */
2496 
2497 /**
2498  * gpiochip_generic_request() - request the gpio function for a pin
2499  * @chip: the gpiochip owning the GPIO
2500  * @offset: the offset of the GPIO to request for GPIO function
2501  */
2502 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
2503 {
2504         return pinctrl_gpio_request(chip->gpiodev->base + offset);
2505 }
2506 EXPORT_SYMBOL_GPL(gpiochip_generic_request);
2507 
2508 /**
2509  * gpiochip_generic_free() - free the gpio function from a pin
2510  * @chip: the gpiochip to request the gpio function for
2511  * @offset: the offset of the GPIO to free from GPIO function
2512  */
2513 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
2514 {
2515         pinctrl_gpio_free(chip->gpiodev->base + offset);
2516 }
2517 EXPORT_SYMBOL_GPL(gpiochip_generic_free);
2518 
2519 /**
2520  * gpiochip_generic_config() - apply configuration for a pin
2521  * @chip: the gpiochip owning the GPIO
2522  * @offset: the offset of the GPIO to apply the configuration
2523  * @config: the configuration to be applied
2524  */
2525 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
2526                             unsigned long config)
2527 {
2528         return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
2529 }
2530 EXPORT_SYMBOL_GPL(gpiochip_generic_config);
2531 
2532 #ifdef CONFIG_PINCTRL
2533 
2534 /**
2535  * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
2536  * @chip: the gpiochip to add the range for
2537  * @pctldev: the pin controller to map to
2538  * @gpio_offset: the start offset in the current gpio_chip number space
2539  * @pin_group: name of the pin group inside the pin controller
2540  *
2541  * Calling this function directly from a DeviceTree-supported
2542  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2543  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2544  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2545  */
2546 int gpiochip_add_pingroup_range(struct gpio_chip *chip,
2547                         struct pinctrl_dev *pctldev,
2548                         unsigned int gpio_offset, const char *pin_group)
2549 {
2550         struct gpio_pin_range *pin_range;
2551         struct gpio_device *gdev = chip->gpiodev;
2552         int ret;
2553 
2554         pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2555         if (!pin_range) {
2556                 chip_err(chip, "failed to allocate pin ranges\n");
2557                 return -ENOMEM;
2558         }
2559 
2560         /* Use local offset as range ID */
2561         pin_range->range.id = gpio_offset;
2562         pin_range->range.gc = chip;
2563         pin_range->range.name = chip->label;
2564         pin_range->range.base = gdev->base + gpio_offset;
2565         pin_range->pctldev = pctldev;
2566 
2567         ret = pinctrl_get_group_pins(pctldev, pin_group,
2568                                         &pin_range->range.pins,
2569                                         &pin_range->range.npins);
2570         if (ret < 0) {
2571                 kfree(pin_range);
2572                 return ret;
2573         }
2574 
2575         pinctrl_add_gpio_range(pctldev, &pin_range->range);
2576 
2577         chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
2578                  gpio_offset, gpio_offset + pin_range->range.npins - 1,
2579                  pinctrl_dev_get_devname(pctldev), pin_group);
2580 
2581         list_add_tail(&pin_range->node, &gdev->pin_ranges);
2582 
2583         return 0;
2584 }
2585 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
2586 
2587 /**
2588  * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
2589  * @chip: the gpiochip to add the range for
2590  * @pinctl_name: the dev_name() of the pin controller to map to
2591  * @gpio_offset: the start offset in the current gpio_chip number space
2592  * @pin_offset: the start offset in the pin controller number space
2593  * @npins: the number of pins from the offset of each pin space (GPIO and
2594  *      pin controller) to accumulate in this range
2595  *
2596  * Returns:
2597  * 0 on success, or a negative error-code on failure.
2598  *
2599  * Calling this function directly from a DeviceTree-supported
2600  * pinctrl driver is DEPRECATED. Please see Section 2.1 of
2601  * Documentation/devicetree/bindings/gpio/gpio.txt on how to
2602  * bind pinctrl and gpio drivers via the "gpio-ranges" property.
2603  */
2604 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
2605                            unsigned int gpio_offset, unsigned int pin_offset,
2606                            unsigned int npins)
2607 {
2608         struct gpio_pin_range *pin_range;
2609         struct gpio_device *gdev = chip->gpiodev;
2610         int ret;
2611 
2612         pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
2613         if (!pin_range) {
2614                 chip_err(chip, "failed to allocate pin ranges\n");
2615                 return -ENOMEM;
2616         }
2617 
2618         /* Use local offset as range ID */
2619         pin_range->range.id = gpio_offset;
2620         pin_range->range.gc = chip;
2621         pin_range->range.name = chip->label;
2622         pin_range->range.base = gdev->base + gpio_offset;
2623         pin_range->range.pin_base = pin_offset;
2624         pin_range->range.npins = npins;
2625         pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
2626                         &pin_range->range);
2627         if (IS_ERR(pin_range->pctldev)) {
2628                 ret = PTR_ERR(pin_range->pctldev);
2629                 chip_err(chip, "could not create pin range\n");
2630                 kfree(pin_range);
2631                 return ret;
2632         }
2633         chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
2634                  gpio_offset, gpio_offset + npins - 1,
2635                  pinctl_name,
2636                  pin_offset, pin_offset + npins - 1);
2637 
2638         list_add_tail(&pin_range->node, &gdev->pin_ranges);
2639 
2640         return 0;
2641 }
2642 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
2643 
2644 /**
2645  * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
2646  * @chip: the chip to remove all the mappings for
2647  */
2648 void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
2649 {
2650         struct gpio_pin_range *pin_range, *tmp;
2651         struct gpio_device *gdev = chip->gpiodev;
2652 
2653         list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
2654                 list_del(&pin_range->node);
2655                 pinctrl_remove_gpio_range(pin_range->pctldev,
2656                                 &pin_range->range);
2657                 kfree(pin_range);
2658         }
2659 }
2660 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
2661 
2662 #endif /* CONFIG_PINCTRL */
2663 
2664 /* These "optional" allocation calls help prevent drivers from stomping
2665  * on each other, and help provide better diagnostics in debugfs.
2666  * They're called even less than the "set direction" calls.
2667  */
2668 static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
2669 {
2670         struct gpio_chip        *chip = desc->gdev->chip;
2671         int                     ret;
2672         unsigned long           flags;
2673         unsigned                offset;
2674 
2675         if (label) {
2676                 label = kstrdup_const(label, GFP_KERNEL);
2677                 if (!label)
2678                         return -ENOMEM;
2679         }
2680 
2681         spin_lock_irqsave(&gpio_lock, flags);
2682 
2683         /* NOTE:  gpio_request() can be called in early boot,
2684          * before IRQs are enabled, for non-sleeping (SOC) GPIOs.
2685          */
2686 
2687         if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
2688                 desc_set_label(desc, label ? : "?");
2689                 ret = 0;
2690         } else {
2691                 kfree_const(label);
2692                 ret = -EBUSY;
2693                 goto done;
2694         }
2695 
2696         if (chip->request) {
2697                 /* chip->request may sleep */
2698                 spin_unlock_irqrestore(&gpio_lock, flags);
2699                 offset = gpio_chip_hwgpio(desc);
2700                 if (gpiochip_line_is_valid(chip, offset))
2701                         ret = chip->request(chip, offset);
2702                 else
2703                         ret = -EINVAL;
2704                 spin_lock_irqsave(&gpio_lock, flags);
2705 
2706                 if (ret < 0) {
2707                         desc_set_label(desc, NULL);
2708                         kfree_const(label);
2709                         clear_bit(FLAG_REQUESTED, &desc->flags);
2710                         goto done;
2711                 }
2712         }
2713         if (chip->get_direction) {
2714                 /* chip->get_direction may sleep */
2715                 spin_unlock_irqrestore(&gpio_lock, flags);
2716                 gpiod_get_direction(desc);
2717                 spin_lock_irqsave(&gpio_lock, flags);
2718         }
2719 done:
2720         spin_unlock_irqrestore(&gpio_lock, flags);
2721         return ret;
2722 }
2723 
2724 /*
2725  * This descriptor validation needs to be inserted verbatim into each
2726  * function taking a descriptor, so we need to use a preprocessor
2727  * macro to avoid endless duplication. If the desc is NULL it is an
2728  * optional GPIO and calls should just bail out.
2729  */
2730 static int validate_desc(const struct gpio_desc *desc, const char *func)
2731 {
2732         if (!desc)
2733                 return 0;
2734         if (IS_ERR(desc)) {
2735                 pr_warn("%s: invalid GPIO (errorpointer)\n", func);
2736                 return PTR_ERR(desc);
2737         }
2738         if (!desc->gdev) {
2739                 pr_warn("%s: invalid GPIO (no device)\n", func);
2740                 return -EINVAL;
2741         }
2742         if (!desc->gdev->chip) {
2743                 dev_warn(&desc->gdev->dev,
2744                          "%s: backing chip is gone\n", func);
2745                 return 0;
2746         }
2747         return 1;
2748 }
2749 
2750 #define VALIDATE_DESC(desc) do { \
2751         int __valid = validate_desc(desc, __func__); \
2752         if (__valid <= 0) \
2753                 return __valid; \
2754         } while (0)
2755 
2756 #define VALIDATE_DESC_VOID(desc) do { \
2757         int __valid = validate_desc(desc, __func__); \
2758         if (__valid <= 0) \
2759                 return; \
2760         } while (0)
2761 
2762 int gpiod_request(struct gpio_desc *desc, const char *label)
2763 {
2764         int ret = -EPROBE_DEFER;
2765         struct gpio_device *gdev;
2766 
2767         VALIDATE_DESC(desc);
2768         gdev = desc->gdev;
2769 
2770         if (try_module_get(gdev->owner)) {
2771                 ret = gpiod_request_commit(desc, label);
2772                 if (ret < 0)
2773                         module_put(gdev->owner);
2774                 else
2775                         get_device(&gdev->dev);
2776         }
2777 
2778         if (ret)
2779                 gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
2780 
2781         return ret;
2782 }
2783 
2784 static bool gpiod_free_commit(struct gpio_desc *desc)
2785 {
2786         bool                    ret = false;
2787         unsigned long           flags;
2788         struct gpio_chip        *chip;
2789 
2790         might_sleep();
2791 
2792         gpiod_unexport(desc);
2793 
2794         spin_lock_irqsave(&gpio_lock, flags);
2795 
2796         chip = desc->gdev->chip;
2797         if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
2798                 if (chip->free) {
2799                         spin_unlock_irqrestore(&gpio_lock, flags);
2800                         might_sleep_if(chip->can_sleep);
2801                         chip->free(chip, gpio_chip_hwgpio(desc));
2802                         spin_lock_irqsave(&gpio_lock, flags);
2803                 }
2804                 kfree_const(desc->label);
2805                 desc_set_label(desc, NULL);
2806                 clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
2807                 clear_bit(FLAG_REQUESTED, &desc->flags);
2808                 clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
2809                 clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
2810                 clear_bit(FLAG_IS_HOGGED, &desc->flags);
2811                 ret = true;
2812         }
2813 
2814         spin_unlock_irqrestore(&gpio_lock, flags);
2815         return ret;
2816 }
2817 
2818 void gpiod_free(struct gpio_desc *desc)
2819 {
2820         if (desc && desc->gdev && gpiod_free_commit(desc)) {
2821                 module_put(desc->gdev->owner);
2822                 put_device(&desc->gdev->dev);
2823         } else {
2824                 WARN_ON(extra_checks);
2825         }
2826 }
2827 
2828 /**
2829  * gpiochip_is_requested - return string iff signal was requested
2830  * @chip: controller managing the signal
2831  * @offset: of signal within controller's 0..(ngpio - 1) range
2832  *
2833  * Returns NULL if the GPIO is not currently requested, else a string.
2834  * The string returned is the label passed to gpio_request(); if none has been
2835  * passed it is a meaningless, non-NULL constant.
2836  *
2837  * This function is for use by GPIO controller drivers.  The label can
2838  * help with diagnostics, and knowing that the signal is used as a GPIO
2839  * can help avoid accidentally multiplexing it to another controller.
2840  */
2841 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
2842 {
2843         struct gpio_desc *desc;
2844 
2845         if (offset >= chip->ngpio)
2846                 return NULL;
2847 
2848         desc = &chip->gpiodev->descs[offset];
2849 
2850         if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
2851                 return NULL;
2852         return desc->label;
2853 }
2854 EXPORT_SYMBOL_GPL(gpiochip_is_requested);
2855 
2856 /**
2857  * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
2858  * @chip: GPIO chip
2859  * @hwnum: hardware number of the GPIO for which to request the descriptor
2860  * @label: label for the GPIO
2861  * @lflags: lookup flags for this GPIO or 0 if default, this can be used to
2862  * specify things like line inversion semantics with the machine flags
2863  * such as GPIO_OUT_LOW
2864  * @dflags: descriptor request flags for this GPIO or 0 if default, this
2865  * can be used to specify consumer semantics such as open drain
2866  *
2867  * Function allows GPIO chip drivers to request and use their own GPIO
2868  * descriptors via gpiolib API. Difference to gpiod_request() is that this
2869  * function will not increase reference count of the GPIO chip module. This
2870  * allows the GPIO chip module to be unloaded as needed (we assume that the
2871  * GPIO chip driver handles freeing the GPIOs it has requested).
2872  *
2873  * Returns:
2874  * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
2875  * code on failure.
2876  */
2877 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
2878                                             const char *label,
2879                                             enum gpio_lookup_flags lflags,
2880                                             enum gpiod_flags dflags)
2881 {
2882         struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
2883         int ret;
2884 
2885         if (IS_ERR(desc)) {
2886                 chip_err(chip, "failed to get GPIO descriptor\n");
2887                 return desc;
2888         }
2889 
2890         ret = gpiod_request_commit(desc, label);
2891         if (ret < 0)
2892                 return ERR_PTR(ret);
2893 
2894         ret = gpiod_configure_flags(desc, label, lflags, dflags);
2895         if (ret) {
2896                 chip_err(chip, "setup of own GPIO %s failed\n", label);
2897                 gpiod_free_commit(desc);
2898                 return ERR_PTR(ret);
2899         }
2900 
2901         return desc;
2902 }
2903 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
2904 
2905 /**
2906  * gpiochip_free_own_desc - Free GPIO requested by the chip driver
2907  * @desc: GPIO descriptor to free
2908  *
2909  * Function frees the given GPIO requested previously with
2910  * gpiochip_request_own_desc().
2911  */
2912 void gpiochip_free_own_desc(struct gpio_desc *desc)
2913 {
2914         if (desc)
2915                 gpiod_free_commit(desc);
2916 }
2917 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
2918 
2919 /*
2920  * Drivers MUST set GPIO direction before making get/set calls.  In
2921  * some cases this is done in early boot, before IRQs are enabled.
2922  *
2923  * As a rule these aren't called more than once (except for drivers
2924  * using the open-drain emulation idiom) so these are natural places
2925  * to accumulate extra debugging checks.  Note that we can't (yet)
2926  * rely on gpio_request() having been called beforehand.
2927  */
2928 
2929 static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
2930                            enum pin_config_param mode)
2931 {
2932         unsigned long config;
2933         unsigned arg;
2934 
2935         switch (mode) {
2936         case PIN_CONFIG_BIAS_PULL_DOWN:
2937         case PIN_CONFIG_BIAS_PULL_UP:
2938                 arg = 1;
2939                 break;
2940 
2941         default:
2942                 arg = 0;
2943         }
2944 
2945         config = PIN_CONF_PACKED(mode, arg);
2946         return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
2947 }
2948 
2949 /**
2950  * gpiod_direction_input - set the GPIO direction to input
2951  * @desc:       GPIO to set to input
2952  *
2953  * Set the direction of the passed GPIO to input, such as gpiod_get_value() can
2954  * be called safely on it.
2955  *
2956  * Return 0 in case of success, else an error code.
2957  */
2958 int gpiod_direction_input(struct gpio_desc *desc)
2959 {
2960         struct gpio_chip        *chip;
2961         int                     ret = 0;
2962 
2963         VALIDATE_DESC(desc);
2964         chip = desc->gdev->chip;
2965 
2966         /*
2967          * It is legal to have no .get() and .direction_input() specified if
2968          * the chip is output-only, but you can't specify .direction_input()
2969          * and not support the .get() operation, that doesn't make sense.
2970          */
2971         if (!chip->get && chip->direction_input) {
2972                 gpiod_warn(desc,
2973                            "%s: missing get() but have direction_input()\n",
2974                            __func__);
2975                 return -EIO;
2976         }
2977 
2978         /*
2979          * If we have a .direction_input() callback, things are simple,
2980          * just call it. Else we are some input-only chip so try to check the
2981          * direction (if .get_direction() is supported) else we silently
2982          * assume we are in input mode after this.
2983          */
2984         if (chip->direction_input) {
2985                 ret = chip->direction_input(chip, gpio_chip_hwgpio(desc));
2986         } else if (chip->get_direction &&
2987                   (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) {
2988                 gpiod_warn(desc,
2989                            "%s: missing direction_input() operation and line is output\n",
2990                            __func__);
2991                 return -EIO;
2992         }
2993         if (ret == 0)
2994                 clear_bit(FLAG_IS_OUT, &desc->flags);
2995 
2996         if (test_bit(FLAG_PULL_UP, &desc->flags))
2997                 gpio_set_config(chip, gpio_chip_hwgpio(desc),
2998                                 PIN_CONFIG_BIAS_PULL_UP);
2999         else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
3000                 gpio_set_config(chip, gpio_chip_hwgpio(desc),
3001                                 PIN_CONFIG_BIAS_PULL_DOWN);
3002 
3003         trace_gpio_direction(desc_to_gpio(desc), 1, ret);
3004 
3005         return ret;
3006 }
3007 EXPORT_SYMBOL_GPL(gpiod_direction_input);
3008 
3009 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
3010 {
3011         struct gpio_chip *gc = desc->gdev->chip;
3012         int val = !!value;
3013         int ret = 0;
3014 
3015         /*
3016          * It's OK not to specify .direction_output() if the gpiochip is
3017          * output-only, but if there is then not even a .set() operation it
3018          * is pretty tricky to drive the output line.
3019          */
3020         if (!gc->set && !gc->direction_output) {
3021                 gpiod_warn(desc,
3022                            "%s: missing set() and direction_output() operations\n",
3023                            __func__);
3024                 return -EIO;
3025         }
3026 
3027         if (gc->direction_output) {
3028                 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
3029         } else {
3030                 /* Check that we are in output mode if we can */
3031                 if (gc->get_direction &&
3032                     gc->get_direction(gc, gpio_chip_hwgpio(desc))) {
3033                         gpiod_warn(desc,
3034                                 "%s: missing direction_output() operation\n",
3035                                 __func__);
3036                         return -EIO;
3037                 }
3038                 /*
3039                  * If we can't actively set the direction, we are some
3040                  * output-only chip, so just drive the output as desired.
3041                  */
3042                 gc->set(gc, gpio_chip_hwgpio(desc), val);
3043         }
3044 
3045         if (!ret)
3046                 set_bit(FLAG_IS_OUT, &desc->flags);
3047         trace_gpio_value(desc_to_gpio(desc), 0, val);
3048         trace_gpio_direction(desc_to_gpio(desc), 0, ret);
3049         return ret;
3050 }
3051 
3052 /**
3053  * gpiod_direction_output_raw - set the GPIO direction to output
3054  * @desc:       GPIO to set to output
3055  * @value:      initial output value of the GPIO
3056  *
3057  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
3058  * be called safely on it. The initial value of the output must be specified
3059  * as raw value on the physical line without regard for the ACTIVE_LOW status.
3060  *
3061  * Return 0 in case of success, else an error code.
3062  */
3063 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
3064 {
3065         VALIDATE_DESC(desc);
3066         return gpiod_direction_output_raw_commit(desc, value);
3067 }
3068 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
3069 
3070 /**
3071  * gpiod_direction_output - set the GPIO direction to output
3072  * @desc:       GPIO to set to output
3073  * @value:      initial output value of the GPIO
3074  *
3075  * Set the direction of the passed GPIO to output, such as gpiod_set_value() can
3076  * be called safely on it. The initial value of the output must be specified
3077  * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
3078  * account.
3079  *
3080  * Return 0 in case of success, else an error code.
3081  */
3082 int gpiod_direction_output(struct gpio_desc *desc, int value)
3083 {
3084         struct gpio_chip *gc;
3085         int ret;
3086 
3087         VALIDATE_DESC(desc);
3088         if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3089                 value = !value;
3090         else
3091                 value = !!value;
3092 
3093         /* GPIOs used for enabled IRQs shall not be set as output */
3094         if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) &&
3095             test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) {
3096                 gpiod_err(desc,
3097                           "%s: tried to set a GPIO tied to an IRQ as output\n",
3098                           __func__);
3099                 return -EIO;
3100         }
3101 
3102         gc = desc->gdev->chip;
3103         if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3104                 /* First see if we can enable open drain in hardware */
3105                 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
3106                                       PIN_CONFIG_DRIVE_OPEN_DRAIN);
3107                 if (!ret)
3108                         goto set_output_value;
3109                 /* Emulate open drain by not actively driving the line high */
3110                 if (value) {
3111                         ret = gpiod_direction_input(desc);
3112                         goto set_output_flag;
3113                 }
3114         }
3115         else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
3116                 ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
3117                                       PIN_CONFIG_DRIVE_OPEN_SOURCE);
3118                 if (!ret)
3119                         goto set_output_value;
3120                 /* Emulate open source by not actively driving the line low */
3121                 if (!value) {
3122                         ret = gpiod_direction_input(desc);
3123                         goto set_output_flag;
3124                 }
3125         } else {
3126                 gpio_set_config(gc, gpio_chip_hwgpio(desc),
3127                                 PIN_CONFIG_DRIVE_PUSH_PULL);
3128         }
3129 
3130 set_output_value:
3131         return gpiod_direction_output_raw_commit(desc, value);
3132 
3133 set_output_flag:
3134         /*
3135          * When emulating open-source or open-drain functionalities by not
3136          * actively driving the line (setting mode to input) we still need to
3137          * set the IS_OUT flag or otherwise we won't be able to set the line
3138          * value anymore.
3139          */
3140         if (ret == 0)
3141                 set_bit(FLAG_IS_OUT, &desc->flags);
3142         return ret;
3143 }
3144 EXPORT_SYMBOL_GPL(gpiod_direction_output);
3145 
3146 /**
3147  * gpiod_set_debounce - sets @debounce time for a GPIO
3148  * @desc: descriptor of the GPIO for which to set debounce time
3149  * @debounce: debounce time in microseconds
3150  *
3151  * Returns:
3152  * 0 on success, %-ENOTSUPP if the controller doesn't support setting the
3153  * debounce time.
3154  */
3155 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
3156 {
3157         struct gpio_chip        *chip;
3158         unsigned long           config;
3159 
3160         VALIDATE_DESC(desc);
3161         chip = desc->gdev->chip;
3162         if (!chip->set || !chip->set_config) {
3163                 gpiod_dbg(desc,
3164                           "%s: missing set() or set_config() operations\n",
3165                           __func__);
3166                 return -ENOTSUPP;
3167         }
3168 
3169         config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
3170         return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
3171 }
3172 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
3173 
3174 /**
3175  * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
3176  * @desc: descriptor of the GPIO for which to configure persistence
3177  * @transitory: True to lose state on suspend or reset, false for persistence
3178  *
3179  * Returns:
3180  * 0 on success, otherwise a negative error code.
3181  */
3182 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
3183 {
3184         struct gpio_chip *chip;
3185         unsigned long packed;
3186         int gpio;
3187         int rc;
3188 
3189         VALIDATE_DESC(desc);
3190         /*
3191          * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
3192          * persistence state.
3193          */
3194         if (transitory)
3195                 set_bit(FLAG_TRANSITORY, &desc->flags);
3196         else
3197                 clear_bit(FLAG_TRANSITORY, &desc->flags);
3198 
3199         /* If the driver supports it, set the persistence state now */
3200         chip = desc->gdev->chip;
3201         if (!chip->set_config)
3202                 return 0;
3203 
3204         packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
3205                                           !transitory);
3206         gpio = gpio_chip_hwgpio(desc);
3207         rc = chip->set_config(chip, gpio, packed);
3208         if (rc == -ENOTSUPP) {
3209                 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
3210                                 gpio);
3211                 return 0;
3212         }
3213 
3214         return rc;
3215 }
3216 EXPORT_SYMBOL_GPL(gpiod_set_transitory);
3217 
3218 /**
3219  * gpiod_is_active_low - test whether a GPIO is active-low or not
3220  * @desc: the gpio descriptor to test
3221  *
3222  * Returns 1 if the GPIO is active-low, 0 otherwise.
3223  */
3224 int gpiod_is_active_low(const struct gpio_desc *desc)
3225 {
3226         VALIDATE_DESC(desc);
3227         return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
3228 }
3229 EXPORT_SYMBOL_GPL(gpiod_is_active_low);
3230 
3231 /**
3232  * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
3233  * @desc: the gpio descriptor to change
3234  */
3235 void gpiod_toggle_active_low(struct gpio_desc *desc)
3236 {
3237         VALIDATE_DESC_VOID(desc);
3238         change_bit(FLAG_ACTIVE_LOW, &desc->flags);
3239 }
3240 EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
3241 
3242 /* I/O calls are only valid after configuration completed; the relevant
3243  * "is this a valid GPIO" error checks should already have been done.
3244  *
3245  * "Get" operations are often inlinable as reading a pin value register,
3246  * and masking the relevant bit in that register.
3247  *
3248  * When "set" operations are inlinable, they involve writing that mask to
3249  * one register to set a low value, or a different register to set it high.
3250  * Otherwise locking is needed, so there may be little value to inlining.
3251  *
3252  *------------------------------------------------------------------------
3253  *
3254  * IMPORTANT!!!  The hot paths -- get/set value -- assume that callers
3255  * have requested the GPIO.  That can include implicit requesting by
3256  * a direction setting call.  Marking a gpio as requested locks its chip
3257  * in memory, guaranteeing that these table lookups need no more locking
3258  * and that gpiochip_remove() will fail.
3259  *
3260  * REVISIT when debugging, consider adding some instrumentation to ensure
3261  * that the GPIO was actually requested.
3262  */
3263 
3264 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
3265 {
3266         struct gpio_chip        *chip;
3267         int offset;
3268         int value;
3269 
3270         chip = desc->gdev->chip;
3271         offset = gpio_chip_hwgpio(desc);
3272         value = chip->get ? chip->get(chip, offset) : -EIO;
3273         value = value < 0 ? value : !!value;
3274         trace_gpio_value(desc_to_gpio(desc), 1, value);
3275         return value;
3276 }
3277 
3278 static int gpio_chip_get_multiple(struct gpio_chip *chip,
3279                                   unsigned long *mask, unsigned long *bits)
3280 {
3281         if (chip->get_multiple) {
3282                 return chip->get_multiple(chip, mask, bits);
3283         } else if (chip->get) {
3284                 int i, value;
3285 
3286                 for_each_set_bit(i, mask, chip->ngpio) {
3287                         value = chip->get(chip, i);
3288                         if (value < 0)
3289                                 return value;
3290                         __assign_bit(i, bits, value);
3291                 }
3292                 return 0;
3293         }
3294         return -EIO;
3295 }
3296 
3297 int gpiod_get_array_value_complex(bool raw, bool can_sleep,
3298                                   unsigned int array_size,
3299                                   struct gpio_desc **desc_array,
3300                                   struct gpio_array *array_info,
3301                                   unsigned long *value_bitmap)
3302 {
3303         int ret, i = 0;
3304 
3305         /*
3306          * Validate array_info against desc_array and its size.
3307          * It should immediately follow desc_array if both
3308          * have been obtained from the same gpiod_get_array() call.
3309          */
3310         if (array_info && array_info->desc == desc_array &&
3311             array_size <= array_info->size &&
3312             (void *)array_info == desc_array + array_info->size) {
3313                 if (!can_sleep)
3314                         WARN_ON(array_info->chip->can_sleep);
3315 
3316                 ret = gpio_chip_get_multiple(array_info->chip,
3317                                              array_info->get_mask,
3318                                              value_bitmap);
3319                 if (ret)
3320                         return ret;
3321 
3322                 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3323                         bitmap_xor(value_bitmap, value_bitmap,
3324                                    array_info->invert_mask, array_size);
3325 
3326                 if (bitmap_full(array_info->get_mask, array_size))
3327                         return 0;
3328 
3329                 i = find_first_zero_bit(array_info->get_mask, array_size);
3330         } else {
3331                 array_info = NULL;
3332         }
3333 
3334         while (i < array_size) {
3335                 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3336                 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3337                 unsigned long *mask, *bits;
3338                 int first, j, ret;
3339 
3340                 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3341                         mask = fastpath;
3342                 } else {
3343                         mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3344                                            sizeof(*mask),
3345                                            can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3346                         if (!mask)
3347                                 return -ENOMEM;
3348                 }
3349 
3350                 bits = mask + BITS_TO_LONGS(chip->ngpio);
3351                 bitmap_zero(mask, chip->ngpio);
3352 
3353                 if (!can_sleep)
3354                         WARN_ON(chip->can_sleep);
3355 
3356                 /* collect all inputs belonging to the same chip */
3357                 first = i;
3358                 do {
3359                         const struct gpio_desc *desc = desc_array[i];
3360                         int hwgpio = gpio_chip_hwgpio(desc);
3361 
3362                         __set_bit(hwgpio, mask);
3363                         i++;
3364 
3365                         if (array_info)
3366                                 i = find_next_zero_bit(array_info->get_mask,
3367                                                        array_size, i);
3368                 } while ((i < array_size) &&
3369                          (desc_array[i]->gdev->chip == chip));
3370 
3371                 ret = gpio_chip_get_multiple(chip, mask, bits);
3372                 if (ret) {
3373                         if (mask != fastpath)
3374                                 kfree(mask);
3375                         return ret;
3376                 }
3377 
3378                 for (j = first; j < i; ) {
3379                         const struct gpio_desc *desc = desc_array[j];
3380                         int hwgpio = gpio_chip_hwgpio(desc);
3381                         int value = test_bit(hwgpio, bits);
3382 
3383                         if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3384                                 value = !value;
3385                         __assign_bit(j, value_bitmap, value);
3386                         trace_gpio_value(desc_to_gpio(desc), 1, value);
3387                         j++;
3388 
3389                         if (array_info)
3390                                 j = find_next_zero_bit(array_info->get_mask, i,
3391                                                        j);
3392                 }
3393 
3394                 if (mask != fastpath)
3395                         kfree(mask);
3396         }
3397         return 0;
3398 }
3399 
3400 /**
3401  * gpiod_get_raw_value() - return a gpio's raw value
3402  * @desc: gpio whose value will be returned
3403  *
3404  * Return the GPIO's raw value, i.e. the value of the physical line disregarding
3405  * its ACTIVE_LOW status, or negative errno on failure.
3406  *
3407  * This function can be called from contexts where we cannot sleep, and will
3408  * complain if the GPIO chip functions potentially sleep.
3409  */
3410 int gpiod_get_raw_value(const struct gpio_desc *desc)
3411 {
3412         VALIDATE_DESC(desc);
3413         /* Should be using gpiod_get_raw_value_cansleep() */
3414         WARN_ON(desc->gdev->chip->can_sleep);
3415         return gpiod_get_raw_value_commit(desc);
3416 }
3417 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
3418 
3419 /**
3420  * gpiod_get_value() - return a gpio's value
3421  * @desc: gpio whose value will be returned
3422  *
3423  * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
3424  * account, or negative errno on failure.
3425  *
3426  * This function can be called from contexts where we cannot sleep, and will
3427  * complain if the GPIO chip functions potentially sleep.
3428  */
3429 int gpiod_get_value(const struct gpio_desc *desc)
3430 {
3431         int value;
3432 
3433         VALIDATE_DESC(desc);
3434         /* Should be using gpiod_get_value_cansleep() */
3435         WARN_ON(desc->gdev->chip->can_sleep);
3436 
3437         value = gpiod_get_raw_value_commit(desc);
3438         if (value < 0)
3439                 return value;
3440 
3441         if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3442                 value = !value;
3443 
3444         return value;
3445 }
3446 EXPORT_SYMBOL_GPL(gpiod_get_value);
3447 
3448 /**
3449  * gpiod_get_raw_array_value() - read raw values from an array of GPIOs
3450  * @array_size: number of elements in the descriptor array / value bitmap
3451  * @desc_array: array of GPIO descriptors whose values will be read
3452  * @array_info: information on applicability of fast bitmap processing path
3453  * @value_bitmap: bitmap to store the read values
3454  *
3455  * Read the raw values of the GPIOs, i.e. the values of the physical lines
3456  * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
3457  * else an error code.
3458  *
3459  * This function can be called from contexts where we cannot sleep,
3460  * and it will complain if the GPIO chip functions potentially sleep.
3461  */
3462 int gpiod_get_raw_array_value(unsigned int array_size,
3463                               struct gpio_desc **desc_array,
3464                               struct gpio_array *array_info,
3465                               unsigned long *value_bitmap)
3466 {
3467         if (!desc_array)
3468                 return -EINVAL;
3469         return gpiod_get_array_value_complex(true, false, array_size,
3470                                              desc_array, array_info,
3471                                              value_bitmap);
3472 }
3473 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
3474 
3475 /**
3476  * gpiod_get_array_value() - read values from an array of GPIOs
3477  * @array_size: number of elements in the descriptor array / value bitmap
3478  * @desc_array: array of GPIO descriptors whose values will be read
3479  * @array_info: information on applicability of fast bitmap processing path
3480  * @value_bitmap: bitmap to store the read values
3481  *
3482  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3483  * into account.  Return 0 in case of success, else an error code.
3484  *
3485  * This function can be called from contexts where we cannot sleep,
3486  * and it will complain if the GPIO chip functions potentially sleep.
3487  */
3488 int gpiod_get_array_value(unsigned int array_size,
3489                           struct gpio_desc **desc_array,
3490                           struct gpio_array *array_info,
3491                           unsigned long *value_bitmap)
3492 {
3493         if (!desc_array)
3494                 return -EINVAL;
3495         return gpiod_get_array_value_complex(false, false, array_size,
3496                                              desc_array, array_info,
3497                                              value_bitmap);
3498 }
3499 EXPORT_SYMBOL_GPL(gpiod_get_array_value);
3500 
3501 /*
3502  *  gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
3503  * @desc: gpio descriptor whose state need to be set.
3504  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3505  */
3506 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
3507 {
3508         int ret = 0;
3509         struct gpio_chip *chip = desc->gdev->chip;
3510         int offset = gpio_chip_hwgpio(desc);
3511 
3512         if (value) {
3513                 ret = chip->direction_input(chip, offset);
3514         } else {
3515                 ret = chip->direction_output(chip, offset, 0);
3516                 if (!ret)
3517                         set_bit(FLAG_IS_OUT, &desc->flags);
3518         }
3519         trace_gpio_direction(desc_to_gpio(desc), value, ret);
3520         if (ret < 0)
3521                 gpiod_err(desc,
3522                           "%s: Error in set_value for open drain err %d\n",
3523                           __func__, ret);
3524 }
3525 
3526 /*
3527  *  _gpio_set_open_source_value() - Set the open source gpio's value.
3528  * @desc: gpio descriptor whose state need to be set.
3529  * @value: Non-zero for setting it HIGH otherwise it will set to LOW.
3530  */
3531 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
3532 {
3533         int ret = 0;
3534         struct gpio_chip *chip = desc->gdev->chip;
3535         int offset = gpio_chip_hwgpio(desc);
3536 
3537         if (value) {
3538                 ret = chip->direction_output(chip, offset, 1);
3539                 if (!ret)
3540                         set_bit(FLAG_IS_OUT, &desc->flags);
3541         } else {
3542                 ret = chip->direction_input(chip, offset);
3543         }
3544         trace_gpio_direction(desc_to_gpio(desc), !value, ret);
3545         if (ret < 0)
3546                 gpiod_err(desc,
3547                           "%s: Error in set_value for open source err %d\n",
3548                           __func__, ret);
3549 }
3550 
3551 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
3552 {
3553         struct gpio_chip        *chip;
3554 
3555         chip = desc->gdev->chip;
3556         trace_gpio_value(desc_to_gpio(desc), 0, value);
3557         chip->set(chip, gpio_chip_hwgpio(desc), value);
3558 }
3559 
3560 /*
3561  * set multiple outputs on the same chip;
3562  * use the chip's set_multiple function if available;
3563  * otherwise set the outputs sequentially;
3564  * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
3565  *        defines which outputs are to be changed
3566  * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
3567  *        defines the values the outputs specified by mask are to be set to
3568  */
3569 static void gpio_chip_set_multiple(struct gpio_chip *chip,
3570                                    unsigned long *mask, unsigned long *bits)
3571 {
3572         if (chip->set_multiple) {
3573                 chip->set_multiple(chip, mask, bits);
3574         } else {
3575                 unsigned int i;
3576 
3577                 /* set outputs if the corresponding mask bit is set */
3578                 for_each_set_bit(i, mask, chip->ngpio)
3579                         chip->set(chip, i, test_bit(i, bits));
3580         }
3581 }
3582 
3583 int gpiod_set_array_value_complex(bool raw, bool can_sleep,
3584                                   unsigned int array_size,
3585                                   struct gpio_desc **desc_array,
3586                                   struct gpio_array *array_info,
3587                                   unsigned long *value_bitmap)
3588 {
3589         int i = 0;
3590 
3591         /*
3592          * Validate array_info against desc_array and its size.
3593          * It should immediately follow desc_array if both
3594          * have been obtained from the same gpiod_get_array() call.
3595          */
3596         if (array_info && array_info->desc == desc_array &&
3597             array_size <= array_info->size &&
3598             (void *)array_info == desc_array + array_info->size) {
3599                 if (!can_sleep)
3600                         WARN_ON(array_info->chip->can_sleep);
3601 
3602                 if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
3603                         bitmap_xor(value_bitmap, value_bitmap,
3604                                    array_info->invert_mask, array_size);
3605 
3606                 gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
3607                                        value_bitmap);
3608 
3609                 if (bitmap_full(array_info->set_mask, array_size))
3610                         return 0;
3611 
3612                 i = find_first_zero_bit(array_info->set_mask, array_size);
3613         } else {
3614                 array_info = NULL;
3615         }
3616 
3617         while (i < array_size) {
3618                 struct gpio_chip *chip = desc_array[i]->gdev->chip;
3619                 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)];
3620                 unsigned long *mask, *bits;
3621                 int count = 0;
3622 
3623                 if (likely(chip->ngpio <= FASTPATH_NGPIO)) {
3624                         mask = fastpath;
3625                 } else {
3626                         mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio),
3627                                            sizeof(*mask),
3628                                            can_sleep ? GFP_KERNEL : GFP_ATOMIC);
3629                         if (!mask)
3630                                 return -ENOMEM;
3631                 }
3632 
3633                 bits = mask + BITS_TO_LONGS(chip->ngpio);
3634                 bitmap_zero(mask, chip->ngpio);
3635 
3636                 if (!can_sleep)
3637                         WARN_ON(chip->can_sleep);
3638 
3639                 do {
3640                         struct gpio_desc *desc = desc_array[i];
3641                         int hwgpio = gpio_chip_hwgpio(desc);
3642                         int value = test_bit(i, value_bitmap);
3643 
3644                         /*
3645                          * Pins applicable for fast input but not for
3646                          * fast output processing may have been already
3647                          * inverted inside the fast path, skip them.
3648                          */
3649                         if (!raw && !(array_info &&
3650                             test_bit(i, array_info->invert_mask)) &&
3651                             test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3652                                 value = !value;
3653                         trace_gpio_value(desc_to_gpio(desc), 0, value);
3654                         /*
3655                          * collect all normal outputs belonging to the same chip
3656                          * open drain and open source outputs are set individually
3657                          */
3658                         if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
3659                                 gpio_set_open_drain_value_commit(desc, value);
3660                         } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
3661                                 gpio_set_open_source_value_commit(desc, value);
3662                         } else {
3663                                 __set_bit(hwgpio, mask);
3664                                 if (value)
3665                                         __set_bit(hwgpio, bits);
3666                                 else
3667                                         __clear_bit(hwgpio, bits);
3668                                 count++;
3669                         }
3670                         i++;
3671 
3672                         if (array_info)
3673                                 i = find_next_zero_bit(array_info->set_mask,
3674                                                        array_size, i);
3675                 } while ((i < array_size) &&
3676                          (desc_array[i]->gdev->chip == chip));
3677                 /* push collected bits to outputs */
3678                 if (count != 0)
3679                         gpio_chip_set_multiple(chip, mask, bits);
3680 
3681                 if (mask != fastpath)
3682                         kfree(mask);
3683         }
3684         return 0;
3685 }
3686 
3687 /**
3688  * gpiod_set_raw_value() - assign a gpio's raw value
3689  * @desc: gpio whose value will be assigned
3690  * @value: value to assign
3691  *
3692  * Set the raw value of the GPIO, i.e. the value of its physical line without
3693  * regard for its ACTIVE_LOW status.
3694  *
3695  * This function can be called from contexts where we cannot sleep, and will
3696  * complain if the GPIO chip functions potentially sleep.
3697  */
3698 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
3699 {
3700         VALIDATE_DESC_VOID(desc);
3701         /* Should be using gpiod_set_raw_value_cansleep() */
3702         WARN_ON(desc->gdev->chip->can_sleep);
3703         gpiod_set_raw_value_commit(desc, value);
3704 }
3705 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
3706 
3707 /**
3708  * gpiod_set_value_nocheck() - set a GPIO line value without checking
3709  * @desc: the descriptor to set the value on
3710  * @value: value to set
3711  *
3712  * This sets the value of a GPIO line backing a descriptor, applying
3713  * different semantic quirks like active low and open drain/source
3714  * handling.
3715  */
3716 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
3717 {
3718         if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
3719                 value = !value;
3720         if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
3721                 gpio_set_open_drain_value_commit(desc, value);
3722         else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
3723                 gpio_set_open_source_value_commit(desc, value);
3724         else
3725                 gpiod_set_raw_value_commit(desc, value);
3726 }
3727 
3728 /**
3729  * gpiod_set_value() - assign a gpio's value
3730  * @desc: gpio whose value will be assigned
3731  * @value: value to assign
3732  *
3733  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
3734  * OPEN_DRAIN and OPEN_SOURCE flags into account.
3735  *
3736  * This function can be called from contexts where we cannot sleep, and will
3737  * complain if the GPIO chip functions potentially sleep.
3738  */
3739 void gpiod_set_value(struct gpio_desc *desc, int value)
3740 {
3741         VALIDATE_DESC_VOID(desc);
3742         /* Should be using gpiod_set_value_cansleep() */
3743         WARN_ON(desc->gdev->chip->can_sleep);
3744         gpiod_set_value_nocheck(desc, value);
3745 }
3746 EXPORT_SYMBOL_GPL(gpiod_set_value);
3747 
3748 /**
3749  * gpiod_set_raw_array_value() - assign values to an array of GPIOs
3750  * @array_size: number of elements in the descriptor array / value bitmap
3751  * @desc_array: array of GPIO descriptors whose values will be assigned
3752  * @array_info: information on applicability of fast bitmap processing path
3753  * @value_bitmap: bitmap of values to assign
3754  *
3755  * Set the raw values of the GPIOs, i.e. the values of the physical lines
3756  * without regard for their ACTIVE_LOW status.
3757  *
3758  * This function can be called from contexts where we cannot sleep, and will
3759  * complain if the GPIO chip functions potentially sleep.
3760  */
3761 int gpiod_set_raw_array_value(unsigned int array_size,
3762                               struct gpio_desc **desc_array,
3763                               struct gpio_array *array_info,
3764                               unsigned long *value_bitmap)
3765 {
3766         if (!desc_array)
3767                 return -EINVAL;
3768         return gpiod_set_array_value_complex(true, false, array_size,
3769                                         desc_array, array_info, value_bitmap);
3770 }
3771 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
3772 
3773 /**
3774  * gpiod_set_array_value() - assign values to an array of GPIOs
3775  * @array_size: number of elements in the descriptor array / value bitmap
3776  * @desc_array: array of GPIO descriptors whose values will be assigned
3777  * @array_info: information on applicability of fast bitmap processing path
3778  * @value_bitmap: bitmap of values to assign
3779  *
3780  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
3781  * into account.
3782  *
3783  * This function can be called from contexts where we cannot sleep, and will
3784  * complain if the GPIO chip functions potentially sleep.
3785  */
3786 int gpiod_set_array_value(unsigned int array_size,
3787                           struct gpio_desc **desc_array,
3788                           struct gpio_array *array_info,
3789                           unsigned long *value_bitmap)
3790 {
3791         if (!desc_array)
3792                 return -EINVAL;
3793         return gpiod_set_array_value_complex(false, false, array_size,
3794                                              desc_array, array_info,
3795                                              value_bitmap);
3796 }
3797 EXPORT_SYMBOL_GPL(gpiod_set_array_value);
3798 
3799 /**
3800  * gpiod_cansleep() - report whether gpio value access may sleep
3801  * @desc: gpio to check
3802  *
3803  */
3804 int gpiod_cansleep(const struct gpio_desc *desc)
3805 {
3806         VALIDATE_DESC(desc);
3807         return desc->gdev->chip->can_sleep;
3808 }
3809 EXPORT_SYMBOL_GPL(gpiod_cansleep);
3810 
3811 /**
3812  * gpiod_set_consumer_name() - set the consumer name for the descriptor
3813  * @desc: gpio to set the consumer name on
3814  * @name: the new consumer name
3815  */
3816 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
3817 {
3818         VALIDATE_DESC(desc);
3819         if (name) {
3820                 name = kstrdup_const(name, GFP_KERNEL);
3821                 if (!name)
3822                         return -ENOMEM;
3823         }
3824 
3825         kfree_const(desc->label);
3826         desc_set_label(desc, name);
3827 
3828         return 0;
3829 }
3830 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
3831 
3832 /**
3833  * gpiod_to_irq() - return the IRQ corresponding to a GPIO
3834  * @desc: gpio whose IRQ will be returned (already requested)
3835  *
3836  * Return the IRQ corresponding to the passed GPIO, or an error code in case of
3837  * error.
3838  */
3839 int gpiod_to_irq(const struct gpio_desc *desc)
3840 {
3841         struct gpio_chip *chip;
3842         int offset;
3843 
3844         /*
3845          * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
3846          * requires this function to not return zero on an invalid descriptor
3847          * but rather a negative error number.
3848          */
3849         if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
3850                 return -EINVAL;
3851 
3852         chip = desc->gdev->chip;
3853         offset = gpio_chip_hwgpio(desc);
3854         if (chip->to_irq) {
3855                 int retirq = chip->to_irq(chip, offset);
3856 
3857                 /* Zero means NO_IRQ */
3858                 if (!retirq)
3859                         return -ENXIO;
3860 
3861                 return retirq;
3862         }
3863         return -ENXIO;
3864 }
3865 EXPORT_SYMBOL_GPL(gpiod_to_irq);
3866 
3867 /**
3868  * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
3869  * @chip: the chip the GPIO to lock belongs to
3870  * @offset: the offset of the GPIO to lock as IRQ
3871  *
3872  * This is used directly by GPIO drivers that want to lock down
3873  * a certain GPIO line to be used for IRQs.
3874  */
3875 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
3876 {
3877         struct gpio_desc *desc;
3878 
3879         desc = gpiochip_get_desc(chip, offset);
3880         if (IS_ERR(desc))
3881                 return PTR_ERR(desc);
3882 
3883         /*
3884          * If it's fast: flush the direction setting if something changed
3885          * behind our back
3886          */
3887         if (!chip->can_sleep && chip->get_direction) {
3888                 int dir = gpiod_get_direction(desc);
3889 
3890                 if (dir < 0) {
3891                         chip_err(chip, "%s: cannot get GPIO direction\n",
3892                                  __func__);
3893                         return dir;
3894                 }
3895         }
3896 
3897         /* To be valid for IRQ the line needs to be input or open drain */
3898         if (test_bit(FLAG_IS_OUT, &desc->flags) &&
3899             !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
3900                 chip_err(chip,
3901                          "%s: tried to flag a GPIO set as output for IRQ\n",
3902                          __func__);
3903                 return -EIO;
3904         }
3905 
3906         set_bit(FLAG_USED_AS_IRQ, &desc->flags);
3907         set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3908 
3909         /*
3910          * If the consumer has not set up a label (such as when the
3911          * IRQ is referenced from .to_irq()) we set up a label here
3912          * so it is clear this is used as an interrupt.
3913          */
3914         if (!desc->label)
3915                 desc_set_label(desc, "interrupt");
3916 
3917         return 0;
3918 }
3919 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
3920 
3921 /**
3922  * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
3923  * @chip: the chip the GPIO to lock belongs to
3924  * @offset: the offset of the GPIO to lock as IRQ
3925  *
3926  * This is used directly by GPIO drivers that want to indicate
3927  * that a certain GPIO is no longer used exclusively for IRQ.
3928  */
3929 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
3930 {
3931         struct gpio_desc *desc;
3932 
3933         desc = gpiochip_get_desc(chip, offset);
3934         if (IS_ERR(desc))
3935                 return;
3936 
3937         clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
3938         clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3939 
3940         /* If we only had this marking, erase it */
3941         if (desc->label && !strcmp(desc->label, "interrupt"))
3942                 desc_set_label(desc, NULL);
3943 }
3944 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
3945 
3946 void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
3947 {
3948         struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3949 
3950         if (!IS_ERR(desc) &&
3951             !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
3952                 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3953 }
3954 EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
3955 
3956 void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset)
3957 {
3958         struct gpio_desc *desc = gpiochip_get_desc(chip, offset);
3959 
3960         if (!IS_ERR(desc) &&
3961             !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
3962                 /*
3963                  * We must not be output when using IRQ UNLESS we are
3964                  * open drain.
3965                  */
3966                 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
3967                         !test_bit(FLAG_OPEN_DRAIN, &desc->flags));
3968                 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
3969         }
3970 }
3971 EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
3972 
3973 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
3974 {
3975         if (offset >= chip->ngpio)
3976                 return false;
3977 
3978         return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
3979 }
3980 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
3981 
3982 int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset)
3983 {
3984         int ret;
3985 
3986         if (!try_module_get(chip->gpiodev->owner))
3987                 return -ENODEV;
3988 
3989         ret = gpiochip_lock_as_irq(chip, offset);
3990         if (ret) {
3991                 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset);
3992                 module_put(chip->gpiodev->owner);
3993                 return ret;
3994         }
3995         return 0;
3996 }
3997 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
3998 
3999 void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset)
4000 {
4001         gpiochip_unlock_as_irq(chip, offset);
4002         module_put(chip->gpiodev->owner);
4003 }
4004 EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
4005 
4006 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
4007 {
4008         if (offset >= chip->ngpio)
4009                 return false;
4010 
4011         return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
4012 }
4013 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
4014 
4015 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
4016 {
4017         if (offset >= chip->ngpio)
4018                 return false;
4019 
4020         return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags);
4021 }
4022 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
4023 
4024 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
4025 {
4026         if (offset >= chip->ngpio)
4027                 return false;
4028 
4029         return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags);
4030 }
4031 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
4032 
4033 /**
4034  * gpiod_get_raw_value_cansleep() - return a gpio's raw value
4035  * @desc: gpio whose value will be returned
4036  *
4037  * Return the GPIO's raw value, i.e. the value of the physical line disregarding
4038  * its ACTIVE_LOW status, or negative errno on failure.
4039  *
4040  * This function is to be called from contexts that can sleep.
4041  */
4042 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
4043 {
4044         might_sleep_if(extra_checks);
4045         VALIDATE_DESC(desc);
4046         return gpiod_get_raw_value_commit(desc);
4047 }
4048 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
4049 
4050 /**
4051  * gpiod_get_value_cansleep() - return a gpio's value
4052  * @desc: gpio whose value will be returned
4053  *
4054  * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
4055  * account, or negative errno on failure.
4056  *
4057  * This function is to be called from contexts that can sleep.
4058  */
4059 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
4060 {
4061         int value;
4062 
4063         might_sleep_if(extra_checks);
4064         VALIDATE_DESC(desc);
4065         value = gpiod_get_raw_value_commit(desc);
4066         if (value < 0)
4067                 return value;
4068 
4069         if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
4070                 value = !value;
4071 
4072         return value;
4073 }
4074 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
4075 
4076 /**
4077  * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
4078  * @array_size: number of elements in the descriptor array / value bitmap
4079  * @desc_array: array of GPIO descriptors whose values will be read
4080  * @array_info: information on applicability of fast bitmap processing path
4081  * @value_bitmap: bitmap to store the read values
4082  *
4083  * Read the raw values of the GPIOs, i.e. the values of the physical lines
4084  * without regard for their ACTIVE_LOW status.  Return 0 in case of success,
4085  * else an error code.
4086  *
4087  * This function is to be called from contexts that can sleep.
4088  */
4089 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
4090                                        struct gpio_desc **desc_array,
4091                                        struct gpio_array *array_info,
4092                                        unsigned long *value_bitmap)
4093 {
4094         might_sleep_if(extra_checks);
4095         if (!desc_array)
4096                 return -EINVAL;
4097         return gpiod_get_array_value_complex(true, true, array_size,
4098                                              desc_array, array_info,
4099                                              value_bitmap);
4100 }
4101 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
4102 
4103 /**
4104  * gpiod_get_array_value_cansleep() - read values from an array of GPIOs
4105  * @array_size: number of elements in the descriptor array / value bitmap
4106  * @desc_array: array of GPIO descriptors whose values will be read
4107  * @array_info: information on applicability of fast bitmap processing path
4108  * @value_bitmap: bitmap to store the read values
4109  *
4110  * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4111  * into account.  Return 0 in case of success, else an error code.
4112  *
4113  * This function is to be called from contexts that can sleep.
4114  */
4115 int gpiod_get_array_value_cansleep(unsigned int array_size,
4116                                    struct gpio_desc **desc_array,
4117                                    struct gpio_array *array_info,
4118                                    unsigned long *value_bitmap)
4119 {
4120         might_sleep_if(extra_checks);
4121         if (!desc_array)
4122                 return -EINVAL;
4123         return gpiod_get_array_value_complex(false, true, array_size,
4124                                              desc_array, array_info,
4125                                              value_bitmap);
4126 }
4127 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
4128 
4129 /**
4130  * gpiod_set_raw_value_cansleep() - assign a gpio's raw value
4131  * @desc: gpio whose value will be assigned
4132  * @value: value to assign
4133  *
4134  * Set the raw value of the GPIO, i.e. the value of its physical line without
4135  * regard for its ACTIVE_LOW status.
4136  *
4137  * This function is to be called from contexts that can sleep.
4138  */
4139 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
4140 {
4141         might_sleep_if(extra_checks);
4142         VALIDATE_DESC_VOID(desc);
4143         gpiod_set_raw_value_commit(desc, value);
4144 }
4145 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
4146 
4147 /**
4148  * gpiod_set_value_cansleep() - assign a gpio's value
4149  * @desc: gpio whose value will be assigned
4150  * @value: value to assign
4151  *
4152  * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
4153  * account
4154  *
4155  * This function is to be called from contexts that can sleep.
4156  */
4157 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
4158 {
4159         might_sleep_if(extra_checks);
4160         VALIDATE_DESC_VOID(desc);
4161         gpiod_set_value_nocheck(desc, value);
4162 }
4163 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
4164 
4165 /**
4166  * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
4167  * @array_size: number of elements in the descriptor array / value bitmap
4168  * @desc_array: array of GPIO descriptors whose values will be assigned
4169  * @array_info: information on applicability of fast bitmap processing path
4170  * @value_bitmap: bitmap of values to assign
4171  *
4172  * Set the raw values of the GPIOs, i.e. the values of the physical lines
4173  * without regard for their ACTIVE_LOW status.
4174  *
4175  * This function is to be called from contexts that can sleep.
4176  */
4177 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
4178                                        struct gpio_desc **desc_array,
4179                                        struct gpio_array *array_info,
4180                                        unsigned long *value_bitmap)
4181 {
4182         might_sleep_if(extra_checks);
4183         if (!desc_array)
4184                 return -EINVAL;
4185         return gpiod_set_array_value_complex(true, true, array_size, desc_array,
4186                                       array_info, value_bitmap);
4187 }
4188 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
4189 
4190 /**
4191  * gpiod_add_lookup_tables() - register GPIO device consumers
4192  * @tables: list of tables of consumers to register
4193  * @n: number of tables in the list
4194  */
4195 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
4196 {
4197         unsigned int i;
4198 
4199         mutex_lock(&gpio_lookup_lock);
4200 
4201         for (i = 0; i < n; i++)
4202                 list_add_tail(&tables[i]->list, &gpio_lookup_list);
4203 
4204         mutex_unlock(&gpio_lookup_lock);
4205 }
4206 
4207 /**
4208  * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
4209  * @array_size: number of elements in the descriptor array / value bitmap
4210  * @desc_array: array of GPIO descriptors whose values will be assigned
4211  * @array_info: information on applicability of fast bitmap processing path
4212  * @value_bitmap: bitmap of values to assign
4213  *
4214  * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
4215  * into account.
4216  *
4217  * This function is to be called from contexts that can sleep.
4218  */
4219 int gpiod_set_array_value_cansleep(unsigned int array_size,
4220                                    struct gpio_desc **desc_array,
4221                                    struct gpio_array *array_info,
4222                                    unsigned long *value_bitmap)
4223 {
4224         might_sleep_if(extra_checks);
4225         if (!desc_array)
4226                 return -EINVAL;
4227         return gpiod_set_array_value_complex(false, true, array_size,
4228                                              desc_array, array_info,
4229                                              value_bitmap);
4230 }
4231 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
4232 
4233 /**
4234  * gpiod_add_lookup_table() - register GPIO device consumers
4235  * @table: table of consumers to register
4236  */
4237 void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
4238 {
4239         mutex_lock(&gpio_lookup_lock);
4240 
4241         list_add_tail(&table->list, &gpio_lookup_list);
4242 
4243         mutex_unlock(&gpio_lookup_lock);
4244 }
4245 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
4246 
4247 /**
4248  * gpiod_remove_lookup_table() - unregister GPIO device consumers
4249  * @table: table of consumers to unregister
4250  */
4251 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
4252 {
4253         mutex_lock(&gpio_lookup_lock);
4254 
4255         list_del(&table->list);
4256 
4257         mutex_unlock(&gpio_lookup_lock);
4258 }
4259 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
4260 
4261 /**
4262  * gpiod_add_hogs() - register a set of GPIO hogs from machine code
4263  * @hogs: table of gpio hog entries with a zeroed sentinel at the end
4264  */
4265 void gpiod_add_hogs(struct gpiod_hog *hogs)
4266 {
4267         struct gpio_chip *chip;
4268         struct gpiod_hog *hog;
4269 
4270         mutex_lock(&gpio_machine_hogs_mutex);
4271 
4272         for (hog = &hogs[0]; hog->chip_label; hog++) {
4273                 list_add_tail(&hog->list, &gpio_machine_hogs);
4274 
4275                 /*
4276                  * The chip may have been registered earlier, so check if it
4277                  * exists and, if so, try to hog the line now.
4278                  */
4279                 chip = find_chip_by_name(hog->chip_label);
4280                 if (chip)
4281                         gpiochip_machine_hog(chip, hog);
4282         }
4283 
4284         mutex_unlock(&gpio_machine_hogs_mutex);
4285 }
4286 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
4287 
4288 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
4289 {
4290         const char *dev_id = dev ? dev_name(dev) : NULL;
4291         struct gpiod_lookup_table *table;
4292 
4293         mutex_lock(&gpio_lookup_lock);
4294 
4295         list_for_each_entry(table, &gpio_lookup_list, list) {
4296                 if (table->dev_id && dev_id) {
4297                         /*
4298                          * Valid strings on both ends, must be identical to have
4299                          * a match
4300                          */
4301                         if (!strcmp(table->dev_id, dev_id))
4302                                 goto found;
4303                 } else {
4304                         /*
4305                          * One of the pointers is NULL, so both must be to have
4306                          * a match
4307                          */
4308                         if (dev_id == table->dev_id)
4309                                 goto found;
4310                 }
4311         }
4312         table = NULL;
4313 
4314 found:
4315         mutex_unlock(&gpio_lookup_lock);
4316         return table;
4317 }
4318 
4319 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
4320                                     unsigned int idx, unsigned long *flags)
4321 {
4322         struct gpio_desc *desc = ERR_PTR(-ENOENT);
4323         struct gpiod_lookup_table *table;
4324         struct gpiod_lookup *p;
4325 
4326         table = gpiod_find_lookup_table(dev);
4327         if (!table)
4328                 return desc;
4329 
4330         for (p = &table->table[0]; p->chip_label; p++) {
4331                 struct gpio_chip *chip;
4332 
4333                 /* idx must always match exactly */
4334                 if (p->idx != idx)
4335                         continue;
4336 
4337                 /* If the lookup entry has a con_id, require exact match */
4338                 if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
4339                         continue;
4340 
4341                 chip = find_chip_by_name(p->chip_label);
4342 
4343                 if (!chip) {
4344                         /*
4345                          * As the lookup table indicates a chip with
4346                          * p->chip_label should exist, assume it may
4347                          * still appear later and let the interested
4348                          * consumer be probed again or let the Deferred
4349                          * Probe infrastructure handle the error.
4350                          */
4351                         dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
4352                                  p->chip_label);
4353                         return ERR_PTR(-EPROBE_DEFER);
4354                 }
4355 
4356                 if (chip->ngpio <= p->chip_hwnum) {
4357                         dev_err(dev,
4358                                 "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
4359                                 idx, p->chip_hwnum, chip->ngpio - 1,
4360                                 chip->label);
4361                         return ERR_PTR(-EINVAL);
4362                 }
4363 
4364                 desc = gpiochip_get_desc(chip, p->chip_hwnum);
4365                 *flags = p->flags;
4366 
4367                 return desc;
4368         }
4369 
4370         return desc;
4371 }
4372 
4373 static int platform_gpio_count(struct device *dev, const char *con_id)
4374 {
4375         struct gpiod_lookup_table *table;
4376         struct gpiod_lookup *p;
4377         unsigned int count = 0;
4378 
4379         table = gpiod_find_lookup_table(dev);
4380         if (!table)
4381                 return -ENOENT;
4382 
4383         for (p = &table->table[0]; p->chip_label; p++) {
4384                 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
4385                     (!con_id && !p->con_id))
4386                         count++;
4387         }
4388         if (!count)
4389                 return -ENOENT;
4390 
4391         return count;
4392 }
4393 
4394 /**
4395  * gpiod_count - return the number of GPIOs associated with a device / function
4396  *              or -ENOENT if no GPIO has been assigned to the requested function
4397  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
4398  * @con_id:     function within the GPIO consumer
4399  */
4400 int gpiod_count(struct device *dev, const char *con_id)
4401 {
4402         int count = -ENOENT;
4403 
4404         if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node)
4405                 count = of_gpio_get_count(dev, con_id);
4406         else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev))
4407                 count = acpi_gpio_count(dev, con_id);
4408 
4409         if (count < 0)
4410                 count = platform_gpio_count(dev, con_id);
4411 
4412         return count;
4413 }
4414 EXPORT_SYMBOL_GPL(gpiod_count);
4415 
4416 /**
4417  * gpiod_get - obtain a GPIO for a given GPIO function
4418  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
4419  * @con_id:     function within the GPIO consumer
4420  * @flags:      optional GPIO initialization flags
4421  *
4422  * Return the GPIO descriptor corresponding to the function con_id of device
4423  * dev, -ENOENT if no GPIO has been assigned to the requested function, or
4424  * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
4425  */
4426 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
4427                                          enum gpiod_flags flags)
4428 {
4429         return gpiod_get_index(dev, con_id, 0, flags);
4430 }
4431 EXPORT_SYMBOL_GPL(gpiod_get);
4432 
4433 /**
4434  * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
4435  * @dev: GPIO consumer, can be NULL for system-global GPIOs
4436  * @con_id: function within the GPIO consumer
4437  * @flags: optional GPIO initialization flags
4438  *
4439  * This is equivalent to gpiod_get(), except that when no GPIO was assigned to
4440  * the requested function it will return NULL. This is convenient for drivers
4441  * that need to handle optional GPIOs.
4442  */
4443 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
4444                                                   const char *con_id,
4445                                                   enum gpiod_flags flags)
4446 {
4447         return gpiod_get_index_optional(dev, con_id, 0, flags);
4448 }
4449 EXPORT_SYMBOL_GPL(gpiod_get_optional);
4450 
4451 
4452 /**
4453  * gpiod_configure_flags - helper function to configure a given GPIO
4454  * @desc:       gpio whose value will be assigned
4455  * @con_id:     function within the GPIO consumer
4456  * @lflags:     bitmask of gpio_lookup_flags GPIO_* values - returned from
4457  *              of_find_gpio() or of_get_gpio_hog()
4458  * @dflags:     gpiod_flags - optional GPIO initialization flags
4459  *
4460  * Return 0 on success, -ENOENT if no GPIO has been assigned to the
4461  * requested function and/or index, or another IS_ERR() code if an error
4462  * occurred while trying to acquire the GPIO.
4463  */
4464 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
4465                 unsigned long lflags, enum gpiod_flags dflags)
4466 {
4467         int ret;
4468 
4469         if (lflags & GPIO_ACTIVE_LOW)
4470                 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
4471 
4472         if (lflags & GPIO_OPEN_DRAIN)
4473                 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4474         else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
4475                 /*
4476                  * This enforces open drain mode from the consumer side.
4477                  * This is necessary for some busses like I2C, but the lookup
4478                  * should *REALLY* have specified them as open drain in the
4479                  * first place, so print a little warning here.
4480                  */
4481                 set_bit(FLAG_OPEN_DRAIN, &desc->flags);
4482                 gpiod_warn(desc,
4483                            "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
4484         }
4485 
4486         if (lflags & GPIO_OPEN_SOURCE)
4487                 set_bit(FLAG_OPEN_SOURCE, &desc->flags);
4488 
4489         if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
4490                 gpiod_err(desc,
4491                           "both pull-up and pull-down enabled, invalid configuration\n");
4492                 return -EINVAL;
4493         }
4494 
4495         if (lflags & GPIO_PULL_UP)
4496                 set_bit(FLAG_PULL_UP, &desc->flags);
4497         else if (lflags & GPIO_PULL_DOWN)
4498                 set_bit(FLAG_PULL_DOWN, &desc->flags);
4499 
4500         ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
4501         if (ret < 0)
4502                 return ret;
4503 
4504         /* No particular flag request, return here... */
4505         if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
4506                 pr_debug("no flags found for %s\n", con_id);
4507                 return 0;
4508         }
4509 
4510         /* Process flags */
4511         if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
4512                 ret = gpiod_direction_output(desc,
4513                                 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
4514         else
4515                 ret = gpiod_direction_input(desc);
4516 
4517         return ret;
4518 }
4519 
4520 /**
4521  * gpiod_get_index - obtain a GPIO from a multi-index GPIO function
4522  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
4523  * @con_id:     function within the GPIO consumer
4524  * @idx:        index of the GPIO to obtain in the consumer
4525  * @flags:      optional GPIO initialization flags
4526  *
4527  * This variant of gpiod_get() allows to access GPIOs other than the first
4528  * defined one for functions that define several GPIOs.
4529  *
4530  * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
4531  * requested function and/or index, or another IS_ERR() code if an error
4532  * occurred while trying to acquire the GPIO.
4533  */
4534 struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
4535                                                const char *con_id,
4536                                                unsigned int idx,
4537                                                enum gpiod_flags flags)
4538 {
4539         unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4540         struct gpio_desc *desc = NULL;
4541         int ret;
4542         /* Maybe we have a device name, maybe not */
4543         const char *devname = dev ? dev_name(dev) : "?";
4544 
4545         dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
4546 
4547         if (dev) {
4548                 /* Using device tree? */
4549                 if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
4550                         dev_dbg(dev, "using device tree for GPIO lookup\n");
4551                         desc = of_find_gpio(dev, con_id, idx, &lookupflags);
4552                 } else if (ACPI_COMPANION(dev)) {
4553                         dev_dbg(dev, "using ACPI for GPIO lookup\n");
4554                         desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags);
4555                 }
4556         }
4557 
4558         /*
4559          * Either we are not using DT or ACPI, or their lookup did not return
4560          * a result. In that case, use platform lookup as a fallback.
4561          */
4562         if (!desc || desc == ERR_PTR(-ENOENT)) {
4563                 dev_dbg(dev, "using lookup tables for GPIO lookup\n");
4564                 desc = gpiod_find(dev, con_id, idx, &lookupflags);
4565         }
4566 
4567         if (IS_ERR(desc)) {
4568                 dev_dbg(dev, "No GPIO consumer %s found\n", con_id);
4569                 return desc;
4570         }
4571 
4572         /*
4573          * If a connection label was passed use that, else attempt to use
4574          * the device name as label
4575          */
4576         ret = gpiod_request(desc, con_id ? con_id : devname);
4577         if (ret < 0) {
4578                 if (ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
4579                         /*
4580                          * This happens when there are several consumers for
4581                          * the same GPIO line: we just return here without
4582                          * further initialization. It is a bit if a hack.
4583                          * This is necessary to support fixed regulators.
4584                          *
4585                          * FIXME: Make this more sane and safe.
4586                          */
4587                         dev_info(dev, "nonexclusive access to GPIO for %s\n",
4588                                  con_id ? con_id : devname);
4589                         return desc;
4590                 } else {
4591                         return ERR_PTR(ret);
4592                 }
4593         }
4594 
4595         ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
4596         if (ret < 0) {
4597                 dev_dbg(dev, "setup of GPIO %s failed\n", con_id);
4598                 gpiod_put(desc);
4599                 return ERR_PTR(ret);
4600         }
4601 
4602         return desc;
4603 }
4604 EXPORT_SYMBOL_GPL(gpiod_get_index);
4605 
4606 /**
4607  * fwnode_get_named_gpiod - obtain a GPIO from firmware node
4608  * @fwnode:     handle of the firmware node
4609  * @propname:   name of the firmware property representing the GPIO
4610  * @index:      index of the GPIO to obtain for the consumer
4611  * @dflags:     GPIO initialization flags
4612  * @label:      label to attach to the requested GPIO
4613  *
4614  * This function can be used for drivers that get their configuration
4615  * from opaque firmware.
4616  *
4617  * The function properly finds the corresponding GPIO using whatever is the
4618  * underlying firmware interface and then makes sure that the GPIO
4619  * descriptor is requested before it is returned to the caller.
4620  *
4621  * Returns:
4622  * On successful request the GPIO pin is configured in accordance with
4623  * provided @dflags.
4624  *
4625  * In case of error an ERR_PTR() is returned.
4626  */
4627 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
4628                                          const char *propname, int index,
4629                                          enum gpiod_flags dflags,
4630                                          const char *label)
4631 {
4632         unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
4633         struct gpio_desc *desc = ERR_PTR(-ENODEV);
4634         int ret;
4635 
4636         if (!fwnode)
4637                 return ERR_PTR(-EINVAL);
4638 
4639         if (is_of_node(fwnode)) {
4640                 desc = gpiod_get_from_of_node(to_of_node(fwnode),
4641                                               propname, index,
4642                                               dflags,
4643                                               label);
4644                 return desc;
4645         } else if (is_acpi_node(fwnode)) {
4646                 struct acpi_gpio_info info;
4647 
4648                 desc = acpi_node_get_gpiod(fwnode, propname, index, &info);
4649                 if (IS_ERR(desc))
4650                         return desc;
4651 
4652                 acpi_gpio_update_gpiod_flags(&dflags, &info);
4653                 acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
4654         }
4655 
4656         /* Currently only ACPI takes this path */
4657         ret = gpiod_request(desc, label);
4658         if (ret)
4659                 return ERR_PTR(ret);
4660 
4661         ret = gpiod_configure_flags(desc, propname, lflags, dflags);
4662         if (ret < 0) {
4663                 gpiod_put(desc);
4664                 return ERR_PTR(ret);
4665         }
4666 
4667         return desc;
4668 }
4669 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
4670 
4671 /**
4672  * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
4673  *                            function
4674  * @dev: GPIO consumer, can be NULL for system-global GPIOs
4675  * @con_id: function within the GPIO consumer
4676  * @index: index of the GPIO to obtain in the consumer
4677  * @flags: optional GPIO initialization flags
4678  *
4679  * This is equivalent to gpiod_get_index(), except that when no GPIO with the
4680  * specified index was assigned to the requested function it will return NULL.
4681  * This is convenient for drivers that need to handle optional GPIOs.
4682  */
4683 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
4684                                                         const char *con_id,
4685                                                         unsigned int index,
4686                                                         enum gpiod_flags flags)
4687 {
4688         struct gpio_desc *desc;
4689 
4690         desc = gpiod_get_index(dev, con_id, index, flags);
4691         if (IS_ERR(desc)) {
4692                 if (PTR_ERR(desc) == -ENOENT)
4693                         return NULL;
4694         }
4695 
4696         return desc;
4697 }
4698 EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
4699 
4700 /**
4701  * gpiod_hog - Hog the specified GPIO desc given the provided flags
4702  * @desc:       gpio whose value will be assigned
4703  * @name:       gpio line name
4704  * @lflags:     bitmask of gpio_lookup_flags GPIO_* values - returned from
4705  *              of_find_gpio() or of_get_gpio_hog()
4706  * @dflags:     gpiod_flags - optional GPIO initialization flags
4707  */
4708 int gpiod_hog(struct gpio_desc *desc, const char *name,
4709               unsigned long lflags, enum gpiod_flags dflags)
4710 {
4711         struct gpio_chip *chip;
4712         struct gpio_desc *local_desc;
4713         int hwnum;
4714         int ret;
4715 
4716         chip = gpiod_to_chip(desc);
4717         hwnum = gpio_chip_hwgpio(desc);
4718 
4719         local_desc = gpiochip_request_own_desc(chip, hwnum, name,
4720                                                lflags, dflags);
4721         if (IS_ERR(local_desc)) {
4722                 ret = PTR_ERR(local_desc);
4723                 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
4724                        name, chip->label, hwnum, ret);
4725                 return ret;
4726         }
4727 
4728         /* Mark GPIO as hogged so it can be identified and removed later */
4729         set_bit(FLAG_IS_HOGGED, &desc->flags);
4730 
4731         pr_info("GPIO line %d (%s) hogged as %s%s\n",
4732                 desc_to_gpio(desc), name,
4733                 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
4734                 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ?
4735                   (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":"");
4736 
4737         return 0;
4738 }
4739 
4740 /**
4741  * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
4742  * @chip:       gpio chip to act on
4743  */
4744 static void gpiochip_free_hogs(struct gpio_chip *chip)
4745 {
4746         int id;
4747 
4748         for (id = 0; id < chip->ngpio; id++) {
4749                 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags))
4750                         gpiochip_free_own_desc(&chip->gpiodev->descs[id]);
4751         }
4752 }
4753 
4754 /**
4755  * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
4756  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
4757  * @con_id:     function within the GPIO consumer
4758  * @flags:      optional GPIO initialization flags
4759  *
4760  * This function acquires all the GPIOs defined under a given function.
4761  *
4762  * Return a struct gpio_descs containing an array of descriptors, -ENOENT if
4763  * no GPIO has been assigned to the requested function, or another IS_ERR()
4764  * code if an error occurred while trying to acquire the GPIOs.
4765  */
4766 struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
4767                                                 const char *con_id,
4768                                                 enum gpiod_flags flags)
4769 {
4770         struct gpio_desc *desc;
4771         struct gpio_descs *descs;
4772         struct gpio_array *array_info = NULL;
4773         struct gpio_chip *chip;
4774         int count, bitmap_size;
4775 
4776         count = gpiod_count(dev, con_id);
4777         if (count < 0)
4778                 return ERR_PTR(count);
4779 
4780         descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL);
4781         if (!descs)
4782                 return ERR_PTR(-ENOMEM);
4783 
4784         for (descs->ndescs = 0; descs->ndescs < count; ) {
4785                 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
4786                 if (IS_ERR(desc)) {
4787                         gpiod_put_array(descs);
4788                         return ERR_CAST(desc);
4789                 }
4790 
4791                 descs->desc[descs->ndescs] = desc;
4792 
4793                 chip = gpiod_to_chip(desc);
4794                 /*
4795                  * If pin hardware number of array member 0 is also 0, select
4796                  * its chip as a candidate for fast bitmap processing path.
4797                  */
4798                 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
4799                         struct gpio_descs *array;
4800 
4801                         bitmap_size = BITS_TO_LONGS(chip->ngpio > count ?
4802                                                     chip->ngpio : count);
4803 
4804                         array = kzalloc(struct_size(descs, desc, count) +
4805                                         struct_size(array_info, invert_mask,
4806                                         3 * bitmap_size), GFP_KERNEL);
4807                         if (!array) {
4808                                 gpiod_put_array(descs);
4809                                 return ERR_PTR(-ENOMEM);
4810                         }
4811 
4812                         memcpy(array, descs,
4813                                struct_size(descs, desc, descs->ndescs + 1));
4814                         kfree(descs);
4815 
4816                         descs = array;
4817                         array_info = (void *)(descs->desc + count);
4818                         array_info->get_mask = array_info->invert_mask +
4819                                                   bitmap_size;
4820                         array_info->set_mask = array_info->get_mask +
4821                                                   bitmap_size;
4822 
4823                         array_info->desc = descs->desc;
4824                         array_info->size = count;
4825                         array_info->chip = chip;
4826                         bitmap_set(array_info->get_mask, descs->ndescs,
4827                                    count - descs->ndescs);
4828                         bitmap_set(array_info->set_mask, descs->ndescs,
4829                                    count - descs->ndescs);
4830                         descs->info = array_info;
4831                 }
4832                 /* Unmark array members which don't belong to the 'fast' chip */
4833                 if (array_info && array_info->chip != chip) {
4834                         __clear_bit(descs->ndescs, array_info->get_mask);
4835                         __clear_bit(descs->ndescs, array_info->set_mask);
4836                 }
4837                 /*
4838                  * Detect array members which belong to the 'fast' chip
4839                  * but their pins are not in hardware order.
4840                  */
4841                 else if (array_info &&
4842                            gpio_chip_hwgpio(desc) != descs->ndescs) {
4843                         /*
4844                          * Don't use fast path if all array members processed so
4845                          * far belong to the same chip as this one but its pin
4846                          * hardware number is different from its array index.
4847                          */
4848                         if (bitmap_full(array_info->get_mask, descs->ndescs)) {
4849                                 array_info = NULL;
4850                         } else {
4851                                 __clear_bit(descs->ndescs,
4852                                             array_info->get_mask);
4853                                 __clear_bit(descs->ndescs,
4854                                             array_info->set_mask);
4855                         }
4856                 } else if (array_info) {
4857                         /* Exclude open drain or open source from fast output */
4858                         if (gpiochip_line_is_open_drain(chip, descs->ndescs) ||
4859                             gpiochip_line_is_open_source(chip, descs->ndescs))
4860                                 __clear_bit(descs->ndescs,
4861                                             array_info->set_mask);
4862                         /* Identify 'fast' pins which require invertion */
4863                         if (gpiod_is_active_low(desc))
4864                                 __set_bit(descs->ndescs,
4865                                           array_info->invert_mask);
4866                 }
4867 
4868                 descs->ndescs++;
4869         }
4870         if (array_info)
4871                 dev_dbg(dev,
4872                         "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
4873                         array_info->chip->label, array_info->size,
4874                         *array_info->get_mask, *array_info->set_mask,
4875                         *array_info->invert_mask);
4876         return descs;
4877 }
4878 EXPORT_SYMBOL_GPL(gpiod_get_array);
4879 
4880 /**
4881  * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
4882  *                            function
4883  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
4884  * @con_id:     function within the GPIO consumer
4885  * @flags:      optional GPIO initialization flags
4886  *
4887  * This is equivalent to gpiod_get_array(), except that when no GPIO was
4888  * assigned to the requested function it will return NULL.
4889  */
4890 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
4891                                                         const char *con_id,
4892                                                         enum gpiod_flags flags)
4893 {
4894         struct gpio_descs *descs;
4895 
4896         descs = gpiod_get_array(dev, con_id, flags);
4897         if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT))
4898                 return NULL;
4899 
4900         return descs;
4901 }
4902 EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
4903 
4904 /**
4905  * gpiod_put - dispose of a GPIO descriptor
4906  * @desc:       GPIO descriptor to dispose of
4907  *
4908  * No descriptor can be used after gpiod_put() has been called on it.
4909  */
4910 void gpiod_put(struct gpio_desc *desc)
4911 {
4912         if (desc)
4913                 gpiod_free(desc);
4914 }
4915 EXPORT_SYMBOL_GPL(gpiod_put);
4916 
4917 /**
4918  * gpiod_put_array - dispose of multiple GPIO descriptors
4919  * @descs:      struct gpio_descs containing an array of descriptors
4920  */
4921 void gpiod_put_array(struct gpio_descs *descs)
4922 {
4923         unsigned int i;
4924 
4925         for (i = 0; i < descs->ndescs; i++)
4926                 gpiod_put(descs->desc[i]);
4927 
4928         kfree(descs);
4929 }
4930 EXPORT_SYMBOL_GPL(gpiod_put_array);
4931 
4932 static int __init gpiolib_dev_init(void)
4933 {
4934         int ret;
4935 
4936         /* Register GPIO sysfs bus */
4937         ret = bus_register(&gpio_bus_type);
4938         if (ret < 0) {
4939                 pr_err("gpiolib: could not register GPIO bus type\n");
4940                 return ret;
4941         }
4942 
4943         ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
4944         if (ret < 0) {
4945                 pr_err("gpiolib: failed to allocate char dev region\n");
4946                 bus_unregister(&gpio_bus_type);
4947         } else {
4948                 gpiolib_initialized = true;
4949                 gpiochip_setup_devs();
4950         }
4951         return ret;
4952 }
4953 core_initcall(gpiolib_dev_init);
4954 
4955 #ifdef CONFIG_DEBUG_FS
4956 
4957 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
4958 {
4959         unsigned                i;
4960         struct gpio_chip        *chip = gdev->chip;
4961         unsigned                gpio = gdev->base;
4962         struct gpio_desc        *gdesc = &gdev->descs[0];
4963         bool                    is_out;
4964         bool                    is_irq;
4965         bool                    active_low;
4966 
4967         for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) {
4968                 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) {
4969                         if (gdesc->name) {
4970                                 seq_printf(s, " gpio-%-3d (%-20.20s)\n",
4971                                            gpio, gdesc->name);
4972                         }
4973                         continue;
4974                 }
4975 
4976                 gpiod_get_direction(gdesc);
4977                 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
4978                 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
4979                 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags);
4980                 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s",
4981                         gpio, gdesc->name ? gdesc->name : "", gdesc->label,
4982                         is_out ? "out" : "in ",
4983                         chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "?  ",
4984                         is_irq ? "IRQ " : "",
4985                         active_low ? "ACTIVE LOW" : "");
4986                 seq_printf(s, "\n");
4987         }
4988 }
4989 
4990 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
4991 {
4992         unsigned long flags;
4993         struct gpio_device *gdev = NULL;
4994         loff_t index = *pos;
4995 
4996         s->private = "";
4997 
4998         spin_lock_irqsave(&gpio_lock, flags);
4999         list_for_each_entry(gdev, &gpio_devices, list)
5000                 if (index-- == 0) {
5001                         spin_unlock_irqrestore(&gpio_lock, flags);
5002                         return gdev;
5003                 }
5004         spin_unlock_irqrestore(&gpio_lock, flags);
5005 
5006         return NULL;
5007 }
5008 
5009 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
5010 {
5011         unsigned long flags;
5012         struct gpio_device *gdev = v;
5013         void *ret = NULL;
5014 
5015         spin_lock_irqsave(&gpio_lock, flags);
5016         if (list_is_last(&gdev->list, &gpio_devices))
5017                 ret = NULL;
5018         else
5019                 ret = list_entry(gdev->list.next, struct gpio_device, list);
5020         spin_unlock_irqrestore(&gpio_lock, flags);
5021 
5022         s->private = "\n";
5023         ++*pos;
5024 
5025         return ret;
5026 }
5027 
5028 static void gpiolib_seq_stop(struct seq_file *s, void *v)
5029 {
5030 }
5031 
5032 static int gpiolib_seq_show(struct seq_file *s, void *v)
5033 {
5034         struct gpio_device *gdev = v;
5035         struct gpio_chip *chip = gdev->chip;
5036         struct device *parent;
5037 
5038         if (!chip) {
5039                 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
5040                            dev_name(&gdev->dev));
5041                 return 0;
5042         }
5043 
5044         seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
5045                    dev_name(&gdev->dev),
5046                    gdev->base, gdev->base + gdev->ngpio - 1);
5047         parent = chip->parent;
5048         if (parent)
5049                 seq_printf(s, ", parent: %s/%s",
5050                            parent->bus ? parent->bus->name : "no-bus",
5051                            dev_name(parent));
5052         if (chip->label)
5053                 seq_printf(s, ", %s", chip->label);
5054         if (chip->can_sleep)
5055                 seq_printf(s, ", can sleep");
5056         seq_printf(s, ":\n");
5057 
5058         if (chip->dbg_show)
5059                 chip->dbg_show(s, chip);
5060         else
5061                 gpiolib_dbg_show(s, gdev);
5062 
5063         return 0;
5064 }
5065 
5066 static const struct seq_operations gpiolib_seq_ops = {
5067         .start = gpiolib_seq_start,
5068         .next = gpiolib_seq_next,
5069         .stop = gpiolib_seq_stop,
5070         .show = gpiolib_seq_show,
5071 };
5072 
5073 static int gpiolib_open(struct inode *inode, struct file *file)
5074 {
5075         return seq_open(file, &gpiolib_seq_ops);
5076 }
5077 
5078 static const struct file_operations gpiolib_operations = {
5079         .owner          = THIS_MODULE,
5080         .open           = gpiolib_open,
5081         .read           = seq_read,
5082         .llseek         = seq_lseek,
5083         .release        = seq_release,
5084 };
5085 
5086 static int __init gpiolib_debugfs_init(void)
5087 {
5088         /* /sys/kernel/debug/gpio */
5089         debugfs_create_file("gpio", S_IFREG | S_IRUGO, NULL, NULL,
5090                             &gpiolib_operations);
5091         return 0;
5092 }
5093 subsys_initcall(gpiolib_debugfs_init);
5094 
5095 #endif  /* DEBUG_FS */