root/include/linux/leds.h

INCLUDED FROM

DEFINITIONS

1. led_classdev_register
2. devm_led_classdev_register
3. led_sysfs_is_disabled
4. led_set_trigger_data
5. led_get_trigger_data
6. led_trigger_register_simple
7. led_trigger_unregister_simple
8. led_trigger_event
9. led_trigger_blink
10. led_trigger_blink_oneshot
11. led_trigger_set_default
12. led_trigger_set
13. led_trigger_remove
14. led_set_trigger_data
15. led_get_trigger_data
16. ledtrig_disk_activity
17. ledtrig_mtd_activity
18. ledtrig_flash_ctrl
19. ledtrig_torch_ctrl
20. gpio_led_register_device
21. ledtrig_cpu
22. led_classdev_notify_brightness_hw_changed
23. ledtrig_audio_get
24. ledtrig_audio_set

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Driver model for leds and led triggers
   4  *
   5  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
   6  * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
   7  */
   8 #ifndef __LINUX_LEDS_H_INCLUDED
   9 #define __LINUX_LEDS_H_INCLUDED
  10 
  11 #include <dt-bindings/leds/common.h>
  12 #include <linux/device.h>
  13 #include <linux/kernfs.h>
  14 #include <linux/list.h>
  15 #include <linux/mutex.h>
  16 #include <linux/rwsem.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/timer.h>
  19 #include <linux/workqueue.h>
  20 
  21 struct device;
  22 struct led_pattern;
  23 /*
  24  * LED Core
  25  */
  26 
  27 enum led_brightness {
  28         LED_OFF         = 0,
  29         LED_ON          = 1,
  30         LED_HALF        = 127,
  31         LED_FULL        = 255,
  32 };
  33 
  34 struct led_init_data {
  35         /* device fwnode handle */
  36         struct fwnode_handle *fwnode;
  37         /*
  38          * default <color:function> tuple, for backward compatibility
  39          * with in-driver hard-coded LED names used as a fallback when
  40          * DT "label" property is absent; it should be set to NULL
  41          * in new LED class drivers.
  42          */
  43         const char *default_label;
  44         /*
  45          * string to be used for devicename section of LED class device
  46          * either for label based LED name composition path or for fwnode
  47          * based when devname_mandatory is true
  48          */
  49         const char *devicename;
  50         /*
  51          * indicates if LED name should always comprise devicename section;
  52          * only LEDs exposed by drivers of hot-pluggable devices should
  53          * set it to true
  54          */
  55         bool devname_mandatory;
  56 };
  57 
  58 struct led_classdev {
  59         const char              *name;
  60         enum led_brightness      brightness;
  61         enum led_brightness      max_brightness;
  62         int                      flags;
  63 
  64         /* Lower 16 bits reflect status */
  65 #define LED_SUSPENDED           BIT(0)
  66 #define LED_UNREGISTERING       BIT(1)
  67         /* Upper 16 bits reflect control information */
  68 #define LED_CORE_SUSPENDRESUME  BIT(16)
  69 #define LED_SYSFS_DISABLE       BIT(17)
  70 #define LED_DEV_CAP_FLASH       BIT(18)
  71 #define LED_HW_PLUGGABLE        BIT(19)
  72 #define LED_PANIC_INDICATOR     BIT(20)
  73 #define LED_BRIGHT_HW_CHANGED   BIT(21)
  74 #define LED_RETAIN_AT_SHUTDOWN  BIT(22)
  75 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
  76 
  77         /* set_brightness_work / blink_timer flags, atomic, private. */
  78         unsigned long           work_flags;
  79 
  80 #define LED_BLINK_SW                    0
  81 #define LED_BLINK_ONESHOT               1
  82 #define LED_BLINK_ONESHOT_STOP          2
  83 #define LED_BLINK_INVERT                3
  84 #define LED_BLINK_BRIGHTNESS_CHANGE     4
  85 #define LED_BLINK_DISABLE               5
  86 
  87         /* Set LED brightness level
  88          * Must not sleep. Use brightness_set_blocking for drivers
  89          * that can sleep while setting brightness.
  90          */
  91         void            (*brightness_set)(struct led_classdev *led_cdev,
  92                                           enum led_brightness brightness);
  93         /*
  94          * Set LED brightness level immediately - it can block the caller for
  95          * the time required for accessing a LED device register.
  96          */
  97         int (*brightness_set_blocking)(struct led_classdev *led_cdev,
  98                                        enum led_brightness brightness);
  99         /* Get LED brightness level */
 100         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
 101 
 102         /*
 103          * Activate hardware accelerated blink, delays are in milliseconds
 104          * and if both are zero then a sensible default should be chosen.
 105          * The call should adjust the timings in that case and if it can't
 106          * match the values specified exactly.
 107          * Deactivate blinking again when the brightness is set to LED_OFF
 108          * via the brightness_set() callback.
 109          */
 110         int             (*blink_set)(struct led_classdev *led_cdev,
 111                                      unsigned long *delay_on,
 112                                      unsigned long *delay_off);
 113 
 114         int (*pattern_set)(struct led_classdev *led_cdev,
 115                            struct led_pattern *pattern, u32 len, int repeat);
 116         int (*pattern_clear)(struct led_classdev *led_cdev);
 117 
 118         struct device           *dev;
 119         const struct attribute_group    **groups;
 120 
 121         struct list_head         node;                  /* LED Device list */
 122         const char              *default_trigger;       /* Trigger to use */
 123 
 124         unsigned long            blink_delay_on, blink_delay_off;
 125         struct timer_list        blink_timer;
 126         int                      blink_brightness;
 127         int                      new_blink_brightness;
 128         void                    (*flash_resume)(struct led_classdev *led_cdev);
 129 
 130         struct work_struct      set_brightness_work;
 131         int                     delayed_set_value;
 132 
 133 #ifdef CONFIG_LEDS_TRIGGERS
 134         /* Protects the trigger data below */
 135         struct rw_semaphore      trigger_lock;
 136 
 137         struct led_trigger      *trigger;
 138         struct list_head         trig_list;
 139         void                    *trigger_data;
 140         /* true if activated - deactivate routine uses it to do cleanup */
 141         bool                    activated;
 142 #endif
 143 
 144 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 145         int                      brightness_hw_changed;
 146         struct kernfs_node      *brightness_hw_changed_kn;
 147 #endif
 148 
 149         /* Ensures consistent access to the LED Flash Class device */
 150         struct mutex            led_access;
 151 };
 152 
 153 /**
 154  * led_classdev_register_ext - register a new object of LED class with
 155  *                             init data
 156  * @parent: LED controller device this LED is driven by
 157  * @led_cdev: the led_classdev structure for this device
 158  * @init_data: the LED class device initialization data
 159  *
 160  * Register a new object of LED class, with name derived from init_data.
 161  *
 162  * Returns: 0 on success or negative error value on failure
 163  */
 164 extern int led_classdev_register_ext(struct device *parent,
 165                                      struct led_classdev *led_cdev,
 166                                      struct led_init_data *init_data);
 167 
 168 /**
 169  * led_classdev_register - register a new object of LED class
 170  * @parent: LED controller device this LED is driven by
 171  * @led_cdev: the led_classdev structure for this device
 172  *
 173  * Register a new object of LED class, with name derived from the name property
 174  * of passed led_cdev argument.
 175  *
 176  * Returns: 0 on success or negative error value on failure
 177  */
 178 static inline int led_classdev_register(struct device *parent,
 179                                         struct led_classdev *led_cdev)
 180 {
 181         return led_classdev_register_ext(parent, led_cdev, NULL);
 182 }
 183 
 184 extern int devm_led_classdev_register_ext(struct device *parent,
 185                                           struct led_classdev *led_cdev,
 186                                           struct led_init_data *init_data);
 187 
 188 static inline int devm_led_classdev_register(struct device *parent,
 189                                              struct led_classdev *led_cdev)
 190 {
 191         return devm_led_classdev_register_ext(parent, led_cdev, NULL);
 192 }
 193 extern void led_classdev_unregister(struct led_classdev *led_cdev);
 194 extern void devm_led_classdev_unregister(struct device *parent,
 195                                          struct led_classdev *led_cdev);
 196 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 197 extern void led_classdev_resume(struct led_classdev *led_cdev);
 198 
 199 /**
 200  * led_blink_set - set blinking with software fallback
 201  * @led_cdev: the LED to start blinking
 202  * @delay_on: the time it should be on (in ms)
 203  * @delay_off: the time it should ble off (in ms)
 204  *
 205  * This function makes the LED blink, attempting to use the
 206  * hardware acceleration if possible, but falling back to
 207  * software blinking if there is no hardware blinking or if
 208  * the LED refuses the passed values.
 209  *
 210  * Note that if software blinking is active, simply calling
 211  * led_cdev->brightness_set() will not stop the blinking,
 212  * use led_classdev_brightness_set() instead.
 213  */
 214 extern void led_blink_set(struct led_classdev *led_cdev,
 215                           unsigned long *delay_on,
 216                           unsigned long *delay_off);
 217 /**
 218  * led_blink_set_oneshot - do a oneshot software blink
 219  * @led_cdev: the LED to start blinking
 220  * @delay_on: the time it should be on (in ms)
 221  * @delay_off: the time it should ble off (in ms)
 222  * @invert: blink off, then on, leaving the led on
 223  *
 224  * This function makes the LED blink one time for delay_on +
 225  * delay_off time, ignoring the request if another one-shot
 226  * blink is already in progress.
 227  *
 228  * If invert is set, led blinks for delay_off first, then for
 229  * delay_on and leave the led on after the on-off cycle.
 230  */
 231 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 232                                   unsigned long *delay_on,
 233                                   unsigned long *delay_off,
 234                                   int invert);
 235 /**
 236  * led_set_brightness - set LED brightness
 237  * @led_cdev: the LED to set
 238  * @brightness: the brightness to set it to
 239  *
 240  * Set an LED's brightness, and, if necessary, cancel the
 241  * software blink timer that implements blinking when the
 242  * hardware doesn't. This function is guaranteed not to sleep.
 243  */
 244 extern void led_set_brightness(struct led_classdev *led_cdev,
 245                                enum led_brightness brightness);
 246 
 247 /**
 248  * led_set_brightness_sync - set LED brightness synchronously
 249  * @led_cdev: the LED to set
 250  * @value: the brightness to set it to
 251  *
 252  * Set an LED's brightness immediately. This function will block
 253  * the caller for the time required for accessing device registers,
 254  * and it can sleep.
 255  *
 256  * Returns: 0 on success or negative error value on failure
 257  */
 258 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
 259                                    enum led_brightness value);
 260 
 261 /**
 262  * led_update_brightness - update LED brightness
 263  * @led_cdev: the LED to query
 264  *
 265  * Get an LED's current brightness and update led_cdev->brightness
 266  * member with the obtained value.
 267  *
 268  * Returns: 0 on success or negative error value on failure
 269  */
 270 extern int led_update_brightness(struct led_classdev *led_cdev);
 271 
 272 /**
 273  * led_get_default_pattern - return default pattern
 274  *
 275  * @led_cdev: the LED to get default pattern for
 276  * @size:     pointer for storing the number of elements in returned array,
 277  *            modified only if return != NULL
 278  *
 279  * Return:    Allocated array of integers with default pattern from device tree
 280  *            or NULL.  Caller is responsible for kfree().
 281  */
 282 extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
 283                                     unsigned int *size);
 284 
 285 /**
 286  * led_sysfs_disable - disable LED sysfs interface
 287  * @led_cdev: the LED to set
 288  *
 289  * Disable the led_cdev's sysfs interface.
 290  */
 291 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 292 
 293 /**
 294  * led_sysfs_enable - enable LED sysfs interface
 295  * @led_cdev: the LED to set
 296  *
 297  * Enable the led_cdev's sysfs interface.
 298  */
 299 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 300 
 301 /**
 302  * led_compose_name - compose LED class device name
 303  * @dev: LED controller device object
 304  * @init_data: the LED class device initialization data
 305  * @led_classdev_name: composed LED class device name
 306  *
 307  * Create LED class device name basing on the provided init_data argument.
 308  * The name can have <devicename:color:function> or <color:function>.
 309  * form, depending on the init_data configuration.
 310  *
 311  * Returns: 0 on success or negative error value on failure
 312  */
 313 extern int led_compose_name(struct device *dev, struct led_init_data *init_data,
 314                             char *led_classdev_name);
 315 
 316 /**
 317  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 318  * @led_cdev: the LED to query
 319  *
 320  * Returns: true if the led_cdev's sysfs interface is disabled.
 321  */
 322 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 323 {
 324         return led_cdev->flags & LED_SYSFS_DISABLE;
 325 }
 326 
 327 /*
 328  * LED Triggers
 329  */
 330 /* Registration functions for simple triggers */
 331 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 332 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 333 
 334 #ifdef CONFIG_LEDS_TRIGGERS
 335 
 336 #define TRIG_NAME_MAX 50
 337 
 338 struct led_trigger {
 339         /* Trigger Properties */
 340         const char       *name;
 341         int             (*activate)(struct led_classdev *led_cdev);
 342         void            (*deactivate)(struct led_classdev *led_cdev);
 343 
 344         /* LEDs under control by this trigger (for simple triggers) */
 345         rwlock_t          leddev_list_lock;
 346         struct list_head  led_cdevs;
 347 
 348         /* Link to next registered trigger */
 349         struct list_head  next_trig;
 350 
 351         const struct attribute_group **groups;
 352 };
 353 
 354 /*
 355  * Currently the attributes in struct led_trigger::groups are added directly to
 356  * the LED device. As this might change in the future, the following
 357  * macros abstract getting the LED device and its trigger_data from the dev
 358  * parameter passed to the attribute accessor functions.
 359  */
 360 #define led_trigger_get_led(dev)        ((struct led_classdev *)dev_get_drvdata((dev)))
 361 #define led_trigger_get_drvdata(dev)    (led_get_trigger_data(led_trigger_get_led(dev)))
 362 
 363 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 364                         const char *buf, size_t count);
 365 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 366                         char *buf);
 367 
 368 /* Registration functions for complex triggers */
 369 extern int led_trigger_register(struct led_trigger *trigger);
 370 extern void led_trigger_unregister(struct led_trigger *trigger);
 371 extern int devm_led_trigger_register(struct device *dev,
 372                                      struct led_trigger *trigger);
 373 
 374 extern void led_trigger_register_simple(const char *name,
 375                                 struct led_trigger **trigger);
 376 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 377 extern void led_trigger_event(struct led_trigger *trigger,
 378                                 enum led_brightness event);
 379 extern void led_trigger_blink(struct led_trigger *trigger,
 380                               unsigned long *delay_on,
 381                               unsigned long *delay_off);
 382 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 383                                       unsigned long *delay_on,
 384                                       unsigned long *delay_off,
 385                                       int invert);
 386 extern void led_trigger_set_default(struct led_classdev *led_cdev);
 387 extern int led_trigger_set(struct led_classdev *led_cdev,
 388                            struct led_trigger *trigger);
 389 extern void led_trigger_remove(struct led_classdev *led_cdev);
 390 
 391 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
 392                                         void *trigger_data)
 393 {
 394         led_cdev->trigger_data = trigger_data;
 395 }
 396 
 397 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 398 {
 399         return led_cdev->trigger_data;
 400 }
 401 
 402 /**
 403  * led_trigger_rename_static - rename a trigger
 404  * @name: the new trigger name
 405  * @trig: the LED trigger to rename
 406  *
 407  * Change a LED trigger name by copying the string passed in
 408  * name into current trigger name, which MUST be large
 409  * enough for the new string.
 410  *
 411  * Note that name must NOT point to the same string used
 412  * during LED registration, as that could lead to races.
 413  *
 414  * This is meant to be used on triggers with statically
 415  * allocated name.
 416  */
 417 extern void led_trigger_rename_static(const char *name,
 418                                       struct led_trigger *trig);
 419 
 420 #define module_led_trigger(__led_trigger) \
 421         module_driver(__led_trigger, led_trigger_register, \
 422                       led_trigger_unregister)
 423 
 424 #else
 425 
 426 /* Trigger has no members */
 427 struct led_trigger {};
 428 
 429 /* Trigger inline empty functions */
 430 static inline void led_trigger_register_simple(const char *name,
 431                                         struct led_trigger **trigger) {}
 432 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 433 static inline void led_trigger_event(struct led_trigger *trigger,
 434                                 enum led_brightness event) {}
 435 static inline void led_trigger_blink(struct led_trigger *trigger,
 436                                       unsigned long *delay_on,
 437                                       unsigned long *delay_off) {}
 438 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 439                                       unsigned long *delay_on,
 440                                       unsigned long *delay_off,
 441                                       int invert) {}
 442 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 443 static inline int led_trigger_set(struct led_classdev *led_cdev,
 444                                   struct led_trigger *trigger)
 445 {
 446         return 0;
 447 }
 448 
 449 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 450 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
 451 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 452 {
 453         return NULL;
 454 }
 455 
 456 #endif /* CONFIG_LEDS_TRIGGERS */
 457 
 458 /* Trigger specific functions */
 459 #ifdef CONFIG_LEDS_TRIGGER_DISK
 460 extern void ledtrig_disk_activity(bool write);
 461 #else
 462 static inline void ledtrig_disk_activity(bool write) {}
 463 #endif
 464 
 465 #ifdef CONFIG_LEDS_TRIGGER_MTD
 466 extern void ledtrig_mtd_activity(void);
 467 #else
 468 static inline void ledtrig_mtd_activity(void) {}
 469 #endif
 470 
 471 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 472 extern void ledtrig_flash_ctrl(bool on);
 473 extern void ledtrig_torch_ctrl(bool on);
 474 #else
 475 static inline void ledtrig_flash_ctrl(bool on) {}
 476 static inline void ledtrig_torch_ctrl(bool on) {}
 477 #endif
 478 
 479 /*
 480  * Generic LED platform data for describing LED names and default triggers.
 481  */
 482 struct led_info {
 483         const char      *name;
 484         const char      *default_trigger;
 485         int             flags;
 486 };
 487 
 488 struct led_platform_data {
 489         int             num_leds;
 490         struct led_info *leds;
 491 };
 492 
 493 struct led_properties {
 494         u32             color;
 495         bool            color_present;
 496         const char      *function;
 497         u32             func_enum;
 498         bool            func_enum_present;
 499         const char      *label;
 500 };
 501 
 502 struct gpio_desc;
 503 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 504                                 unsigned long *delay_on,
 505                                 unsigned long *delay_off);
 506 
 507 /* For the leds-gpio driver */
 508 struct gpio_led {
 509         const char *name;
 510         const char *default_trigger;
 511         unsigned        gpio;
 512         unsigned        active_low : 1;
 513         unsigned        retain_state_suspended : 1;
 514         unsigned        panic_indicator : 1;
 515         unsigned        default_state : 2;
 516         unsigned        retain_state_shutdown : 1;
 517         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 518         struct gpio_desc *gpiod;
 519 };
 520 #define LEDS_GPIO_DEFSTATE_OFF          0
 521 #define LEDS_GPIO_DEFSTATE_ON           1
 522 #define LEDS_GPIO_DEFSTATE_KEEP         2
 523 
 524 struct gpio_led_platform_data {
 525         int             num_leds;
 526         const struct gpio_led *leds;
 527 
 528 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 529 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 530 #define GPIO_LED_BLINK          2       /* Please, blink */
 531         gpio_blink_set_t        gpio_blink_set;
 532 };
 533 
 534 #ifdef CONFIG_NEW_LEDS
 535 struct platform_device *gpio_led_register_device(
 536                 int id, const struct gpio_led_platform_data *pdata);
 537 #else
 538 static inline struct platform_device *gpio_led_register_device(
 539                 int id, const struct gpio_led_platform_data *pdata)
 540 {
 541         return 0;
 542 }
 543 #endif
 544 
 545 enum cpu_led_event {
 546         CPU_LED_IDLE_START,     /* CPU enters idle */
 547         CPU_LED_IDLE_END,       /* CPU idle ends */
 548         CPU_LED_START,          /* Machine starts, especially resume */
 549         CPU_LED_STOP,           /* Machine stops, especially suspend */
 550         CPU_LED_HALTED,         /* Machine shutdown */
 551 };
 552 #ifdef CONFIG_LEDS_TRIGGER_CPU
 553 extern void ledtrig_cpu(enum cpu_led_event evt);
 554 #else
 555 static inline void ledtrig_cpu(enum cpu_led_event evt)
 556 {
 557         return;
 558 }
 559 #endif
 560 
 561 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 562 extern void led_classdev_notify_brightness_hw_changed(
 563         struct led_classdev *led_cdev, enum led_brightness brightness);
 564 #else
 565 static inline void led_classdev_notify_brightness_hw_changed(
 566         struct led_classdev *led_cdev, enum led_brightness brightness) { }
 567 #endif
 568 
 569 /**
 570  * struct led_pattern - pattern interval settings
 571  * @delta_t: pattern interval delay, in milliseconds
 572  * @brightness: pattern interval brightness
 573  */
 574 struct led_pattern {
 575         u32 delta_t;
 576         int brightness;
 577 };
 578 
 579 enum led_audio {
 580         LED_AUDIO_MUTE,         /* master mute LED */
 581         LED_AUDIO_MICMUTE,      /* mic mute LED */
 582         NUM_AUDIO_LEDS
 583 };
 584 
 585 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
 586 enum led_brightness ledtrig_audio_get(enum led_audio type);
 587 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
 588 #else
 589 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
 590 {
 591         return LED_OFF;
 592 }
 593 static inline void ledtrig_audio_set(enum led_audio type,
 594                                      enum led_brightness state)
 595 {
 596 }
 597 #endif
 598 
 599 #endif          /* __LINUX_LEDS_H_INCLUDED */