drivers/input/keyboard/gpio

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
get_n_events_by_type
get_bm_events_by_type
gpio_keys_disable_button
gpio_keys_enable_button
gpio_keys_attr_show_helper
gpio_keys_attr_store_helper
gpio_keys_gpio_report_event
gpio_keys_gpio_work_func
gpio_keys_gpio_isr
gpio_keys_irq_timer
gpio_keys_irq_isr
gpio_keys_quiesce_key
gpio_keys_setup_key
gpio_keys_report_state
gpio_keys_open
gpio_keys_close
gpio_keys_get_devtree_pdata
gpio_keys_probe
gpio_keys_button_enable_wakeup
gpio_keys_button_disable_wakeup
gpio_keys_enable_wakeup
gpio_keys_disable_wakeup
gpio_keys_suspend
gpio_keys_resume
gpio_keys_shutdown
gpio_keys_init
gpio_keys_exit
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for keys on GPIO lines capable of generating interrupts.
   4  *
   5  * Copyright 2005 Phil Blundell
   6  * Copyright 2010, 2011 David Jander <david@protonic.nl>
   7  */
   8 
   9 #include <linux/module.h>
  10 
  11 #include <linux/init.h>
  12 #include <linux/fs.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <linux/sched.h>
  16 #include <linux/pm.h>
  17 #include <linux/slab.h>
  18 #include <linux/sysctl.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/delay.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/input.h>
  23 #include <linux/gpio_keys.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/gpio.h>
  26 #include <linux/gpio/consumer.h>
  27 #include <linux/of.h>
  28 #include <linux/of_irq.h>
  29 #include <linux/spinlock.h>
  30 #include <dt-bindings/input/gpio-keys.h>
  31 
  32 struct gpio_button_data {
  33         const struct gpio_keys_button *button;
  34         struct input_dev *input;
  35         struct gpio_desc *gpiod;
  36 
  37         unsigned short *code;
  38 
  39         struct timer_list release_timer;
  40         unsigned int release_delay;     /* in msecs, for IRQ-only buttons */
  41 
  42         struct delayed_work work;
  43         unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
  44 
  45         unsigned int irq;
  46         unsigned int wakeup_trigger_type;
  47         spinlock_t lock;
  48         bool disabled;
  49         bool key_pressed;
  50         bool suspended;
  51 };
  52 
  53 struct gpio_keys_drvdata {
  54         const struct gpio_keys_platform_data *pdata;
  55         struct input_dev *input;
  56         struct mutex disable_lock;
  57         unsigned short *keymap;
  58         struct gpio_button_data data[0];
  59 };
  60 
  61 /*
  62  * SYSFS interface for enabling/disabling keys and switches:
  63  *
  64  * There are 4 attributes under /sys/devices/platform/gpio-keys/
  65  *      keys [ro]              - bitmap of keys (EV_KEY) which can be
  66  *                               disabled
  67  *      switches [ro]          - bitmap of switches (EV_SW) which can be
  68  *                               disabled
  69  *      disabled_keys [rw]     - bitmap of keys currently disabled
  70  *      disabled_switches [rw] - bitmap of switches currently disabled
  71  *
  72  * Userland can change these values and hence disable event generation
  73  * for each key (or switch). Disabling a key means its interrupt line
  74  * is disabled.
  75  *
  76  * For example, if we have following switches set up as gpio-keys:
  77  *      SW_DOCK = 5
  78  *      SW_CAMERA_LENS_COVER = 9
  79  *      SW_KEYPAD_SLIDE = 10
  80  *      SW_FRONT_PROXIMITY = 11
  81  * This is read from switches:
  82  *      11-9,5
  83  * Next we want to disable proximity (11) and dock (5), we write:
  84  *      11,5
  85  * to file disabled_switches. Now proximity and dock IRQs are disabled.
  86  * This can be verified by reading the file disabled_switches:
  87  *      11,5
  88  * If we now want to enable proximity (11) switch we write:
  89  *      5
  90  * to disabled_switches.
  91  *
  92  * We can disable only those keys which don't allow sharing the irq.
  93  */
  94 
  95 /**
  96  * get_n_events_by_type() - returns maximum number of events per @type
  97  * @type: type of button (%EV_KEY, %EV_SW)
  98  *
  99  * Return value of this function can be used to allocate bitmap
 100  * large enough to hold all bits for given type.
 101  */
 102 static int get_n_events_by_type(int type)
 103 {
 104         BUG_ON(type != EV_SW && type != EV_KEY);
 105 
 106         return (type == EV_KEY) ? KEY_CNT : SW_CNT;
 107 }
 108 
 109 /**
 110  * get_bm_events_by_type() - returns bitmap of supported events per @type
 111  * @input: input device from which bitmap is retrieved
 112  * @type: type of button (%EV_KEY, %EV_SW)
 113  *
 114  * Return value of this function can be used to allocate bitmap
 115  * large enough to hold all bits for given type.
 116  */
 117 static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
 118                                                   int type)
 119 {
 120         BUG_ON(type != EV_SW && type != EV_KEY);
 121 
 122         return (type == EV_KEY) ? dev->keybit : dev->swbit;
 123 }
 124 
 125 /**
 126  * gpio_keys_disable_button() - disables given GPIO button
 127  * @bdata: button data for button to be disabled
 128  *
 129  * Disables button pointed by @bdata. This is done by masking
 130  * IRQ line. After this function is called, button won't generate
 131  * input events anymore. Note that one can only disable buttons
 132  * that don't share IRQs.
 133  *
 134  * Make sure that @bdata->disable_lock is locked when entering
 135  * this function to avoid races when concurrent threads are
 136  * disabling buttons at the same time.
 137  */
 138 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
 139 {
 140         if (!bdata->disabled) {
 141                 /*
 142                  * Disable IRQ and associated timer/work structure.
 143                  */
 144                 disable_irq(bdata->irq);
 145 
 146                 if (bdata->gpiod)
 147                         cancel_delayed_work_sync(&bdata->work);
 148                 else
 149                         del_timer_sync(&bdata->release_timer);
 150 
 151                 bdata->disabled = true;
 152         }
 153 }
 154 
 155 /**
 156  * gpio_keys_enable_button() - enables given GPIO button
 157  * @bdata: button data for button to be disabled
 158  *
 159  * Enables given button pointed by @bdata.
 160  *
 161  * Make sure that @bdata->disable_lock is locked when entering
 162  * this function to avoid races with concurrent threads trying
 163  * to enable the same button at the same time.
 164  */
 165 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
 166 {
 167         if (bdata->disabled) {
 168                 enable_irq(bdata->irq);
 169                 bdata->disabled = false;
 170         }
 171 }
 172 
 173 /**
 174  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
 175  * @ddata: pointer to drvdata
 176  * @buf: buffer where stringified bitmap is written
 177  * @type: button type (%EV_KEY, %EV_SW)
 178  * @only_disabled: does caller want only those buttons that are
 179  *                 currently disabled or all buttons that can be
 180  *                 disabled
 181  *
 182  * This function writes buttons that can be disabled to @buf. If
 183  * @only_disabled is true, then @buf contains only those buttons
 184  * that are currently disabled. Returns 0 on success or negative
 185  * errno on failure.
 186  */
 187 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
 188                                           char *buf, unsigned int type,
 189                                           bool only_disabled)
 190 {
 191         int n_events = get_n_events_by_type(type);
 192         unsigned long *bits;
 193         ssize_t ret;
 194         int i;
 195 
 196         bits = bitmap_zalloc(n_events, GFP_KERNEL);
 197         if (!bits)
 198                 return -ENOMEM;
 199 
 200         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 201                 struct gpio_button_data *bdata = &ddata->data[i];
 202 
 203                 if (bdata->button->type != type)
 204                         continue;
 205 
 206                 if (only_disabled && !bdata->disabled)
 207                         continue;
 208 
 209                 __set_bit(*bdata->code, bits);
 210         }
 211 
 212         ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
 213         buf[ret++] = '\n';
 214         buf[ret] = '\0';
 215 
 216         bitmap_free(bits);
 217 
 218         return ret;
 219 }
 220 
 221 /**
 222  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
 223  * @ddata: pointer to drvdata
 224  * @buf: buffer from userspace that contains stringified bitmap
 225  * @type: button type (%EV_KEY, %EV_SW)
 226  *
 227  * This function parses stringified bitmap from @buf and disables/enables
 228  * GPIO buttons accordingly. Returns 0 on success and negative error
 229  * on failure.
 230  */
 231 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 232                                            const char *buf, unsigned int type)
 233 {
 234         int n_events = get_n_events_by_type(type);
 235         const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
 236         unsigned long *bits;
 237         ssize_t error;
 238         int i;
 239 
 240         bits = bitmap_zalloc(n_events, GFP_KERNEL);
 241         if (!bits)
 242                 return -ENOMEM;
 243 
 244         error = bitmap_parselist(buf, bits, n_events);
 245         if (error)
 246                 goto out;
 247 
 248         /* First validate */
 249         if (!bitmap_subset(bits, bitmap, n_events)) {
 250                 error = -EINVAL;
 251                 goto out;
 252         }
 253 
 254         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 255                 struct gpio_button_data *bdata = &ddata->data[i];
 256 
 257                 if (bdata->button->type != type)
 258                         continue;
 259 
 260                 if (test_bit(*bdata->code, bits) &&
 261                     !bdata->button->can_disable) {
 262                         error = -EINVAL;
 263                         goto out;
 264                 }
 265         }
 266 
 267         mutex_lock(&ddata->disable_lock);
 268 
 269         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 270                 struct gpio_button_data *bdata = &ddata->data[i];
 271 
 272                 if (bdata->button->type != type)
 273                         continue;
 274 
 275                 if (test_bit(*bdata->code, bits))
 276                         gpio_keys_disable_button(bdata);
 277                 else
 278                         gpio_keys_enable_button(bdata);
 279         }
 280 
 281         mutex_unlock(&ddata->disable_lock);
 282 
 283 out:
 284         bitmap_free(bits);
 285         return error;
 286 }
 287 
 288 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
 289 static ssize_t gpio_keys_show_##name(struct device *dev,                \
 290                                      struct device_attribute *attr,     \
 291                                      char *buf)                         \
 292 {                                                                       \
 293         struct platform_device *pdev = to_platform_device(dev);         \
 294         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 295                                                                         \
 296         return gpio_keys_attr_show_helper(ddata, buf,                   \
 297                                           type, only_disabled);         \
 298 }
 299 
 300 ATTR_SHOW_FN(keys, EV_KEY, false);
 301 ATTR_SHOW_FN(switches, EV_SW, false);
 302 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
 303 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
 304 
 305 /*
 306  * ATTRIBUTES:
 307  *
 308  * /sys/devices/platform/gpio-keys/keys [ro]
 309  * /sys/devices/platform/gpio-keys/switches [ro]
 310  */
 311 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
 312 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
 313 
 314 #define ATTR_STORE_FN(name, type)                                       \
 315 static ssize_t gpio_keys_store_##name(struct device *dev,               \
 316                                       struct device_attribute *attr,    \
 317                                       const char *buf,                  \
 318                                       size_t count)                     \
 319 {                                                                       \
 320         struct platform_device *pdev = to_platform_device(dev);         \
 321         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 322         ssize_t error;                                                  \
 323                                                                         \
 324         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
 325         if (error)                                                      \
 326                 return error;                                           \
 327                                                                         \
 328         return count;                                                   \
 329 }
 330 
 331 ATTR_STORE_FN(disabled_keys, EV_KEY);
 332 ATTR_STORE_FN(disabled_switches, EV_SW);
 333 
 334 /*
 335  * ATTRIBUTES:
 336  *
 337  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
 338  * /sys/devices/platform/gpio-keys/disables_switches [rw]
 339  */
 340 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
 341                    gpio_keys_show_disabled_keys,
 342                    gpio_keys_store_disabled_keys);
 343 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
 344                    gpio_keys_show_disabled_switches,
 345                    gpio_keys_store_disabled_switches);
 346 
 347 static struct attribute *gpio_keys_attrs[] = {
 348         &dev_attr_keys.attr,
 349         &dev_attr_switches.attr,
 350         &dev_attr_disabled_keys.attr,
 351         &dev_attr_disabled_switches.attr,
 352         NULL,
 353 };
 354 ATTRIBUTE_GROUPS(gpio_keys);
 355 
 356 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
 357 {
 358         const struct gpio_keys_button *button = bdata->button;
 359         struct input_dev *input = bdata->input;
 360         unsigned int type = button->type ?: EV_KEY;
 361         int state;
 362 
 363         state = gpiod_get_value_cansleep(bdata->gpiod);
 364         if (state < 0) {
 365                 dev_err(input->dev.parent,
 366                         "failed to get gpio state: %d\n", state);
 367                 return;
 368         }
 369 
 370         if (type == EV_ABS) {
 371                 if (state)
 372                         input_event(input, type, button->code, button->value);
 373         } else {
 374                 input_event(input, type, *bdata->code, state);
 375         }
 376         input_sync(input);
 377 }
 378 
 379 static void gpio_keys_gpio_work_func(struct work_struct *work)
 380 {
 381         struct gpio_button_data *bdata =
 382                 container_of(work, struct gpio_button_data, work.work);
 383 
 384         gpio_keys_gpio_report_event(bdata);
 385 
 386         if (bdata->button->wakeup)
 387                 pm_relax(bdata->input->dev.parent);
 388 }
 389 
 390 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
 391 {
 392         struct gpio_button_data *bdata = dev_id;
 393 
 394         BUG_ON(irq != bdata->irq);
 395 
 396         if (bdata->button->wakeup) {
 397                 const struct gpio_keys_button *button = bdata->button;
 398 
 399                 pm_stay_awake(bdata->input->dev.parent);
 400                 if (bdata->suspended  &&
 401                     (button->type == 0 || button->type == EV_KEY)) {
 402                         /*
 403                          * Simulate wakeup key press in case the key has
 404                          * already released by the time we got interrupt
 405                          * handler to run.
 406                          */
 407                         input_report_key(bdata->input, button->code, 1);
 408                 }
 409         }
 410 
 411         mod_delayed_work(system_wq,
 412                          &bdata->work,
 413                          msecs_to_jiffies(bdata->software_debounce));
 414 
 415         return IRQ_HANDLED;
 416 }
 417 
 418 static void gpio_keys_irq_timer(struct timer_list *t)
 419 {
 420         struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
 421         struct input_dev *input = bdata->input;
 422         unsigned long flags;
 423 
 424         spin_lock_irqsave(&bdata->lock, flags);
 425         if (bdata->key_pressed) {
 426                 input_event(input, EV_KEY, *bdata->code, 0);
 427                 input_sync(input);
 428                 bdata->key_pressed = false;
 429         }
 430         spin_unlock_irqrestore(&bdata->lock, flags);
 431 }
 432 
 433 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
 434 {
 435         struct gpio_button_data *bdata = dev_id;
 436         struct input_dev *input = bdata->input;
 437         unsigned long flags;
 438 
 439         BUG_ON(irq != bdata->irq);
 440 
 441         spin_lock_irqsave(&bdata->lock, flags);
 442 
 443         if (!bdata->key_pressed) {
 444                 if (bdata->button->wakeup)
 445                         pm_wakeup_event(bdata->input->dev.parent, 0);
 446 
 447                 input_event(input, EV_KEY, *bdata->code, 1);
 448                 input_sync(input);
 449 
 450                 if (!bdata->release_delay) {
 451                         input_event(input, EV_KEY, *bdata->code, 0);
 452                         input_sync(input);
 453                         goto out;
 454                 }
 455 
 456                 bdata->key_pressed = true;
 457         }
 458 
 459         if (bdata->release_delay)
 460                 mod_timer(&bdata->release_timer,
 461                         jiffies + msecs_to_jiffies(bdata->release_delay));
 462 out:
 463         spin_unlock_irqrestore(&bdata->lock, flags);
 464         return IRQ_HANDLED;
 465 }
 466 
 467 static void gpio_keys_quiesce_key(void *data)
 468 {
 469         struct gpio_button_data *bdata = data;
 470 
 471         if (bdata->gpiod)
 472                 cancel_delayed_work_sync(&bdata->work);
 473         else
 474                 del_timer_sync(&bdata->release_timer);
 475 }
 476 
 477 static int gpio_keys_setup_key(struct platform_device *pdev,
 478                                 struct input_dev *input,
 479                                 struct gpio_keys_drvdata *ddata,
 480                                 const struct gpio_keys_button *button,
 481                                 int idx,
 482                                 struct fwnode_handle *child)
 483 {
 484         const char *desc = button->desc ? button->desc : "gpio_keys";
 485         struct device *dev = &pdev->dev;
 486         struct gpio_button_data *bdata = &ddata->data[idx];
 487         irq_handler_t isr;
 488         unsigned long irqflags;
 489         int irq;
 490         int error;
 491 
 492         bdata->input = input;
 493         bdata->button = button;
 494         spin_lock_init(&bdata->lock);
 495 
 496         if (child) {
 497                 bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL,
 498                                                                 child,
 499                                                                 GPIOD_IN,
 500                                                                 desc);
 501                 if (IS_ERR(bdata->gpiod)) {
 502                         error = PTR_ERR(bdata->gpiod);
 503                         if (error == -ENOENT) {
 504                                 /*
 505                                  * GPIO is optional, we may be dealing with
 506                                  * purely interrupt-driven setup.
 507                                  */
 508                                 bdata->gpiod = NULL;
 509                         } else {
 510                                 if (error != -EPROBE_DEFER)
 511                                         dev_err(dev, "failed to get gpio: %d\n",
 512                                                 error);
 513                                 return error;
 514                         }
 515                 }
 516         } else if (gpio_is_valid(button->gpio)) {
 517                 /*
 518                  * Legacy GPIO number, so request the GPIO here and
 519                  * convert it to descriptor.
 520                  */
 521                 unsigned flags = GPIOF_IN;
 522 
 523                 if (button->active_low)
 524                         flags |= GPIOF_ACTIVE_LOW;
 525 
 526                 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
 527                 if (error < 0) {
 528                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
 529                                 button->gpio, error);
 530                         return error;
 531                 }
 532 
 533                 bdata->gpiod = gpio_to_desc(button->gpio);
 534                 if (!bdata->gpiod)
 535                         return -EINVAL;
 536         }
 537 
 538         if (bdata->gpiod) {
 539                 bool active_low = gpiod_is_active_low(bdata->gpiod);
 540 
 541                 if (button->debounce_interval) {
 542                         error = gpiod_set_debounce(bdata->gpiod,
 543                                         button->debounce_interval * 1000);
 544                         /* use timer if gpiolib doesn't provide debounce */
 545                         if (error < 0)
 546                                 bdata->software_debounce =
 547                                                 button->debounce_interval;
 548                 }
 549 
 550                 if (button->irq) {
 551                         bdata->irq = button->irq;
 552                 } else {
 553                         irq = gpiod_to_irq(bdata->gpiod);
 554                         if (irq < 0) {
 555                                 error = irq;
 556                                 dev_err(dev,
 557                                         "Unable to get irq number for GPIO %d, error %d\n",
 558                                         button->gpio, error);
 559                                 return error;
 560                         }
 561                         bdata->irq = irq;
 562                 }
 563 
 564                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
 565 
 566                 isr = gpio_keys_gpio_isr;
 567                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 568 
 569                 switch (button->wakeup_event_action) {
 570                 case EV_ACT_ASSERTED:
 571                         bdata->wakeup_trigger_type = active_low ?
 572                                 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
 573                         break;
 574                 case EV_ACT_DEASSERTED:
 575                         bdata->wakeup_trigger_type = active_low ?
 576                                 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
 577                         break;
 578                 case EV_ACT_ANY:
 579                         /* fall through */
 580                 default:
 581                         /*
 582                          * For other cases, we are OK letting suspend/resume
 583                          * not reconfigure the trigger type.
 584                          */
 585                         break;
 586                 }
 587         } else {
 588                 if (!button->irq) {
 589                         dev_err(dev, "Found button without gpio or irq\n");
 590                         return -EINVAL;
 591                 }
 592 
 593                 bdata->irq = button->irq;
 594 
 595                 if (button->type && button->type != EV_KEY) {
 596                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 597                         return -EINVAL;
 598                 }
 599 
 600                 bdata->release_delay = button->debounce_interval;
 601                 timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
 602 
 603                 isr = gpio_keys_irq_isr;
 604                 irqflags = 0;
 605 
 606                 /*
 607                  * For IRQ buttons, there is no interrupt for release.
 608                  * So we don't need to reconfigure the trigger type for wakeup.
 609                  */
 610         }
 611 
 612         bdata->code = &ddata->keymap[idx];
 613         *bdata->code = button->code;
 614         input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
 615 
 616         /*
 617          * Install custom action to cancel release timer and
 618          * workqueue item.
 619          */
 620         error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
 621         if (error) {
 622                 dev_err(dev, "failed to register quiesce action, error: %d\n",
 623                         error);
 624                 return error;
 625         }
 626 
 627         /*
 628          * If platform has specified that the button can be disabled,
 629          * we don't want it to share the interrupt line.
 630          */
 631         if (!button->can_disable)
 632                 irqflags |= IRQF_SHARED;
 633 
 634         error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
 635                                              desc, bdata);
 636         if (error < 0) {
 637                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 638                         bdata->irq, error);
 639                 return error;
 640         }
 641 
 642         return 0;
 643 }
 644 
 645 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 646 {
 647         struct input_dev *input = ddata->input;
 648         int i;
 649 
 650         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 651                 struct gpio_button_data *bdata = &ddata->data[i];
 652                 if (bdata->gpiod)
 653                         gpio_keys_gpio_report_event(bdata);
 654         }
 655         input_sync(input);
 656 }
 657 
 658 static int gpio_keys_open(struct input_dev *input)
 659 {
 660         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 661         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 662         int error;
 663 
 664         if (pdata->enable) {
 665                 error = pdata->enable(input->dev.parent);
 666                 if (error)
 667                         return error;
 668         }
 669 
 670         /* Report current state of buttons that are connected to GPIOs */
 671         gpio_keys_report_state(ddata);
 672 
 673         return 0;
 674 }
 675 
 676 static void gpio_keys_close(struct input_dev *input)
 677 {
 678         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 679         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 680 
 681         if (pdata->disable)
 682                 pdata->disable(input->dev.parent);
 683 }
 684 
 685 /*
 686  * Handlers for alternative sources of platform_data
 687  */
 688 
 689 /*
 690  * Translate properties into platform_data
 691  */
 692 static struct gpio_keys_platform_data *
 693 gpio_keys_get_devtree_pdata(struct device *dev)
 694 {
 695         struct gpio_keys_platform_data *pdata;
 696         struct gpio_keys_button *button;
 697         struct fwnode_handle *child;
 698         int nbuttons;
 699 
 700         nbuttons = device_get_child_node_count(dev);
 701         if (nbuttons == 0)
 702                 return ERR_PTR(-ENODEV);
 703 
 704         pdata = devm_kzalloc(dev,
 705                              sizeof(*pdata) + nbuttons * sizeof(*button),
 706                              GFP_KERNEL);
 707         if (!pdata)
 708                 return ERR_PTR(-ENOMEM);
 709 
 710         button = (struct gpio_keys_button *)(pdata + 1);
 711 
 712         pdata->buttons = button;
 713         pdata->nbuttons = nbuttons;
 714 
 715         pdata->rep = device_property_read_bool(dev, "autorepeat");
 716 
 717         device_property_read_string(dev, "label", &pdata->name);
 718 
 719         device_for_each_child_node(dev, child) {
 720                 if (is_of_node(child))
 721                         button->irq =
 722                                 irq_of_parse_and_map(to_of_node(child), 0);
 723 
 724                 if (fwnode_property_read_u32(child, "linux,code",
 725                                              &button->code)) {
 726                         dev_err(dev, "Button without keycode\n");
 727                         fwnode_handle_put(child);
 728                         return ERR_PTR(-EINVAL);
 729                 }
 730 
 731                 fwnode_property_read_string(child, "label", &button->desc);
 732 
 733                 if (fwnode_property_read_u32(child, "linux,input-type",
 734                                              &button->type))
 735                         button->type = EV_KEY;
 736 
 737                 button->wakeup =
 738                         fwnode_property_read_bool(child, "wakeup-source") ||
 739                         /* legacy name */
 740                         fwnode_property_read_bool(child, "gpio-key,wakeup");
 741 
 742                 fwnode_property_read_u32(child, "wakeup-event-action",
 743                                          &button->wakeup_event_action);
 744 
 745                 button->can_disable =
 746                         fwnode_property_read_bool(child, "linux,can-disable");
 747 
 748                 if (fwnode_property_read_u32(child, "debounce-interval",
 749                                          &button->debounce_interval))
 750                         button->debounce_interval = 5;
 751 
 752                 button++;
 753         }
 754 
 755         return pdata;
 756 }
 757 
 758 static const struct of_device_id gpio_keys_of_match[] = {
 759         { .compatible = "gpio-keys", },
 760         { },
 761 };
 762 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 763 
 764 static int gpio_keys_probe(struct platform_device *pdev)
 765 {
 766         struct device *dev = &pdev->dev;
 767         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 768         struct fwnode_handle *child = NULL;
 769         struct gpio_keys_drvdata *ddata;
 770         struct input_dev *input;
 771         int i, error;
 772         int wakeup = 0;
 773 
 774         if (!pdata) {
 775                 pdata = gpio_keys_get_devtree_pdata(dev);
 776                 if (IS_ERR(pdata))
 777                         return PTR_ERR(pdata);
 778         }
 779 
 780         ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
 781                              GFP_KERNEL);
 782         if (!ddata) {
 783                 dev_err(dev, "failed to allocate state\n");
 784                 return -ENOMEM;
 785         }
 786 
 787         ddata->keymap = devm_kcalloc(dev,
 788                                      pdata->nbuttons, sizeof(ddata->keymap[0]),
 789                                      GFP_KERNEL);
 790         if (!ddata->keymap)
 791                 return -ENOMEM;
 792 
 793         input = devm_input_allocate_device(dev);
 794         if (!input) {
 795                 dev_err(dev, "failed to allocate input device\n");
 796                 return -ENOMEM;
 797         }
 798 
 799         ddata->pdata = pdata;
 800         ddata->input = input;
 801         mutex_init(&ddata->disable_lock);
 802 
 803         platform_set_drvdata(pdev, ddata);
 804         input_set_drvdata(input, ddata);
 805 
 806         input->name = pdata->name ? : pdev->name;
 807         input->phys = "gpio-keys/input0";
 808         input->dev.parent = dev;
 809         input->open = gpio_keys_open;
 810         input->close = gpio_keys_close;
 811 
 812         input->id.bustype = BUS_HOST;
 813         input->id.vendor = 0x0001;
 814         input->id.product = 0x0001;
 815         input->id.version = 0x0100;
 816 
 817         input->keycode = ddata->keymap;
 818         input->keycodesize = sizeof(ddata->keymap[0]);
 819         input->keycodemax = pdata->nbuttons;
 820 
 821         /* Enable auto repeat feature of Linux input subsystem */
 822         if (pdata->rep)
 823                 __set_bit(EV_REP, input->evbit);
 824 
 825         for (i = 0; i < pdata->nbuttons; i++) {
 826                 const struct gpio_keys_button *button = &pdata->buttons[i];
 827 
 828                 if (!dev_get_platdata(dev)) {
 829                         child = device_get_next_child_node(dev, child);
 830                         if (!child) {
 831                                 dev_err(dev,
 832                                         "missing child device node for entry %d\n",
 833                                         i);
 834                                 return -EINVAL;
 835                         }
 836                 }
 837 
 838                 error = gpio_keys_setup_key(pdev, input, ddata,
 839                                             button, i, child);
 840                 if (error) {
 841                         fwnode_handle_put(child);
 842                         return error;
 843                 }
 844 
 845                 if (button->wakeup)
 846                         wakeup = 1;
 847         }
 848 
 849         fwnode_handle_put(child);
 850 
 851         error = input_register_device(input);
 852         if (error) {
 853                 dev_err(dev, "Unable to register input device, error: %d\n",
 854                         error);
 855                 return error;
 856         }
 857 
 858         device_init_wakeup(dev, wakeup);
 859 
 860         return 0;
 861 }
 862 
 863 static int __maybe_unused
 864 gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
 865 {
 866         int error;
 867 
 868         error = enable_irq_wake(bdata->irq);
 869         if (error) {
 870                 dev_err(bdata->input->dev.parent,
 871                         "failed to configure IRQ %d as wakeup source: %d\n",
 872                         bdata->irq, error);
 873                 return error;
 874         }
 875 
 876         if (bdata->wakeup_trigger_type) {
 877                 error = irq_set_irq_type(bdata->irq,
 878                                          bdata->wakeup_trigger_type);
 879                 if (error) {
 880                         dev_err(bdata->input->dev.parent,
 881                                 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
 882                                 bdata->wakeup_trigger_type, bdata->irq, error);
 883                         disable_irq_wake(bdata->irq);
 884                         return error;
 885                 }
 886         }
 887 
 888         return 0;
 889 }
 890 
 891 static void __maybe_unused
 892 gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
 893 {
 894         int error;
 895 
 896         /*
 897          * The trigger type is always both edges for gpio-based keys and we do
 898          * not support changing wakeup trigger for interrupt-based keys.
 899          */
 900         if (bdata->wakeup_trigger_type) {
 901                 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
 902                 if (error)
 903                         dev_warn(bdata->input->dev.parent,
 904                                  "failed to restore interrupt trigger for IRQ %d: %d\n",
 905                                  bdata->irq, error);
 906         }
 907 
 908         error = disable_irq_wake(bdata->irq);
 909         if (error)
 910                 dev_warn(bdata->input->dev.parent,
 911                          "failed to disable IRQ %d as wake source: %d\n",
 912                          bdata->irq, error);
 913 }
 914 
 915 static int __maybe_unused
 916 gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
 917 {
 918         struct gpio_button_data *bdata;
 919         int error;
 920         int i;
 921 
 922         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 923                 bdata = &ddata->data[i];
 924                 if (bdata->button->wakeup) {
 925                         error = gpio_keys_button_enable_wakeup(bdata);
 926                         if (error)
 927                                 goto err_out;
 928                 }
 929                 bdata->suspended = true;
 930         }
 931 
 932         return 0;
 933 
 934 err_out:
 935         while (i--) {
 936                 bdata = &ddata->data[i];
 937                 if (bdata->button->wakeup)
 938                         gpio_keys_button_disable_wakeup(bdata);
 939                 bdata->suspended = false;
 940         }
 941 
 942         return error;
 943 }
 944 
 945 static void __maybe_unused
 946 gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
 947 {
 948         struct gpio_button_data *bdata;
 949         int i;
 950 
 951         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 952                 bdata = &ddata->data[i];
 953                 bdata->suspended = false;
 954                 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
 955                         gpio_keys_button_disable_wakeup(bdata);
 956         }
 957 }
 958 
 959 static int __maybe_unused gpio_keys_suspend(struct device *dev)
 960 {
 961         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 962         struct input_dev *input = ddata->input;
 963         int error;
 964 
 965         if (device_may_wakeup(dev)) {
 966                 error = gpio_keys_enable_wakeup(ddata);
 967                 if (error)
 968                         return error;
 969         } else {
 970                 mutex_lock(&input->mutex);
 971                 if (input->users)
 972                         gpio_keys_close(input);
 973                 mutex_unlock(&input->mutex);
 974         }
 975 
 976         return 0;
 977 }
 978 
 979 static int __maybe_unused gpio_keys_resume(struct device *dev)
 980 {
 981         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 982         struct input_dev *input = ddata->input;
 983         int error = 0;
 984 
 985         if (device_may_wakeup(dev)) {
 986                 gpio_keys_disable_wakeup(ddata);
 987         } else {
 988                 mutex_lock(&input->mutex);
 989                 if (input->users)
 990                         error = gpio_keys_open(input);
 991                 mutex_unlock(&input->mutex);
 992         }
 993 
 994         if (error)
 995                 return error;
 996 
 997         gpio_keys_report_state(ddata);
 998         return 0;
 999 }
1000 
1001 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1002 
1003 static void gpio_keys_shutdown(struct platform_device *pdev)
1004 {
1005         int ret;
1006 
1007         ret = gpio_keys_suspend(&pdev->dev);
1008         if (ret)
1009                 dev_err(&pdev->dev, "failed to shutdown\n");
1010 }
1011 
1012 static struct platform_driver gpio_keys_device_driver = {
1013         .probe          = gpio_keys_probe,
1014         .shutdown       = gpio_keys_shutdown,
1015         .driver         = {
1016                 .name   = "gpio-keys",
1017                 .pm     = &gpio_keys_pm_ops,
1018                 .of_match_table = gpio_keys_of_match,
1019                 .dev_groups     = gpio_keys_groups,
1020         }
1021 };
1022 
1023 static int __init gpio_keys_init(void)
1024 {
1025         return platform_driver_register(&gpio_keys_device_driver);
1026 }
1027 
1028 static void __exit gpio_keys_exit(void)
1029 {
1030         platform_driver_unregister(&gpio_keys_device_driver);
1031 }
1032 
1033 late_initcall(gpio_keys_init);
1034 module_exit(gpio_keys_exit);
1035 
1036 MODULE_LICENSE("GPL");
1037 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1038 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1039 MODULE_ALIAS("platform:gpio-keys");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/input/keyboard/gpio_keys.c

DEFINITIONS
