drivers/input/keyboard/gpio_keys.c

   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
 355 static const struct attribute_group gpio_keys_attr_group = {
 356         .attrs = gpio_keys_attrs,
 357 };
 358
 359 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
 360 {
 361         const struct gpio_keys_button *button = bdata->button;
 362         struct input_dev *input = bdata->input;
 363         unsigned int type = button->type ?: EV_KEY;
 364         int state;
 365
 366         state = gpiod_get_value_cansleep(bdata->gpiod);
 367         if (state < 0) {
 368                 dev_err(input->dev.parent,
 369                         "failed to get gpio state: %d\n", state);
 370                 return;
 371         }
 372
 373         if (type == EV_ABS) {
 374                 if (state)
 375                         input_event(input, type, button->code, button->value);
 376         } else {
 377                 input_event(input, type, *bdata->code, state);
 378         }
 379         input_sync(input);
 380 }
 381
 382 static void gpio_keys_gpio_work_func(struct work_struct *work)
 383 {
 384         struct gpio_button_data *bdata =
 385                 container_of(work, struct gpio_button_data, work.work);
 386
 387         gpio_keys_gpio_report_event(bdata);
 388
 389         if (bdata->button->wakeup)
 390                 pm_relax(bdata->input->dev.parent);
 391 }
 392
 393 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
 394 {
 395         struct gpio_button_data *bdata = dev_id;
 396
 397         BUG_ON(irq != bdata->irq);
 398
 399         if (bdata->button->wakeup) {
 400                 const struct gpio_keys_button *button = bdata->button;
 401
 402                 pm_stay_awake(bdata->input->dev.parent);
 403                 if (bdata->suspended  &&
 404                     (button->type == 0 || button->type == EV_KEY)) {
 405                         /*
 406                          * Simulate wakeup key press in case the key has
 407                          * already released by the time we got interrupt
 408                          * handler to run.
 409                          */
 410                         input_report_key(bdata->input, button->code, 1);
 411                 }
 412         }
 413
 414         mod_delayed_work(system_wq,
 415                          &bdata->work,
 416                          msecs_to_jiffies(bdata->software_debounce));
 417
 418         return IRQ_HANDLED;
 419 }
 420
 421 static void gpio_keys_irq_timer(struct timer_list *t)
 422 {
 423         struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
 424         struct input_dev *input = bdata->input;
 425         unsigned long flags;
 426
 427         spin_lock_irqsave(&bdata->lock, flags);
 428         if (bdata->key_pressed) {
 429                 input_event(input, EV_KEY, *bdata->code, 0);
 430                 input_sync(input);
 431                 bdata->key_pressed = false;
 432         }
 433         spin_unlock_irqrestore(&bdata->lock, flags);
 434 }
 435
 436 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
 437 {
 438         struct gpio_button_data *bdata = dev_id;
 439         struct input_dev *input = bdata->input;
 440         unsigned long flags;
 441
 442         BUG_ON(irq != bdata->irq);
 443
 444         spin_lock_irqsave(&bdata->lock, flags);
 445
 446         if (!bdata->key_pressed) {
 447                 if (bdata->button->wakeup)
 448                         pm_wakeup_event(bdata->input->dev.parent, 0);
 449
 450                 input_event(input, EV_KEY, *bdata->code, 1);
 451                 input_sync(input);
 452
 453                 if (!bdata->release_delay) {
 454                         input_event(input, EV_KEY, *bdata->code, 0);
 455                         input_sync(input);
 456                         goto out;
 457                 }
 458
 459                 bdata->key_pressed = true;
 460         }
 461
 462         if (bdata->release_delay)
 463                 mod_timer(&bdata->release_timer,
 464                         jiffies + msecs_to_jiffies(bdata->release_delay));
 465 out:
 466         spin_unlock_irqrestore(&bdata->lock, flags);
 467         return IRQ_HANDLED;
 468 }
 469
 470 static void gpio_keys_quiesce_key(void *data)
 471 {
 472         struct gpio_button_data *bdata = data;
 473
 474         if (bdata->gpiod)
 475                 cancel_delayed_work_sync(&bdata->work);
 476         else
 477                 del_timer_sync(&bdata->release_timer);
 478 }
 479
 480 static int gpio_keys_setup_key(struct platform_device *pdev,
 481                                 struct input_dev *input,
 482                                 struct gpio_keys_drvdata *ddata,
 483                                 const struct gpio_keys_button *button,
 484                                 int idx,
 485                                 struct fwnode_handle *child)
 486 {
 487         const char *desc = button->desc ? button->desc : "gpio_keys";
 488         struct device *dev = &pdev->dev;
 489         struct gpio_button_data *bdata = &ddata->data[idx];
 490         irq_handler_t isr;
 491         unsigned long irqflags;
 492         int irq;
 493         int error;
 494
 495         bdata->input = input;
 496         bdata->button = button;
 497         spin_lock_init(&bdata->lock);
 498
 499         if (child) {
 500                 bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL,
 501                                                                 child,
 502                                                                 GPIOD_IN,
 503                                                                 desc);
 504                 if (IS_ERR(bdata->gpiod)) {
 505                         error = PTR_ERR(bdata->gpiod);
 506                         if (error == -ENOENT) {
 507                                 /*
 508                                  * GPIO is optional, we may be dealing with
 509                                  * purely interrupt-driven setup.
 510                                  */
 511                                 bdata->gpiod = NULL;
 512                         } else {
 513                                 if (error != -EPROBE_DEFER)
 514                                         dev_err(dev, "failed to get gpio: %d\n",
 515                                                 error);
 516                                 return error;
 517                         }
 518                 }
 519         } else if (gpio_is_valid(button->gpio)) {
 520                 /*
 521                  * Legacy GPIO number, so request the GPIO here and
 522                  * convert it to descriptor.
 523                  */
 524                 unsigned flags = GPIOF_IN;
 525
 526                 if (button->active_low)
 527                         flags |= GPIOF_ACTIVE_LOW;
 528
 529                 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
 530                 if (error < 0) {
 531                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
 532                                 button->gpio, error);
 533                         return error;
 534                 }
 535
 536                 bdata->gpiod = gpio_to_desc(button->gpio);
 537                 if (!bdata->gpiod)
 538                         return -EINVAL;
 539         }
 540
 541         if (bdata->gpiod) {
 542                 bool active_low = gpiod_is_active_low(bdata->gpiod);
 543
 544                 if (button->debounce_interval) {
 545                         error = gpiod_set_debounce(bdata->gpiod,
 546                                         button->debounce_interval * 1000);
 547                         /* use timer if gpiolib doesn't provide debounce */
 548                         if (error < 0)
 549                                 bdata->software_debounce =
 550                                                 button->debounce_interval;
 551                 }
 552
 553                 if (button->irq) {
 554                         bdata->irq = button->irq;
 555                 } else {
 556                         irq = gpiod_to_irq(bdata->gpiod);
 557                         if (irq < 0) {
 558                                 error = irq;
 559                                 dev_err(dev,
 560                                         "Unable to get irq number for GPIO %d, error %d\n",
 561                                         button->gpio, error);
 562                                 return error;
 563                         }
 564                         bdata->irq = irq;
 565                 }
 566
 567                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
 568
 569                 isr = gpio_keys_gpio_isr;
 570                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 571
 572                 switch (button->wakeup_event_action) {
 573                 case EV_ACT_ASSERTED:
 574                         bdata->wakeup_trigger_type = active_low ?
 575                                 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
 576                         break;
 577                 case EV_ACT_DEASSERTED:
 578                         bdata->wakeup_trigger_type = active_low ?
 579                                 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
 580                         break;
 581                 case EV_ACT_ANY:
 582                         /* fall through */
 583                 default:
 584                         /*
 585                          * For other cases, we are OK letting suspend/resume
 586                          * not reconfigure the trigger type.
 587                          */
 588                         break;
 589                 }
 590         } else {
 591                 if (!button->irq) {
 592                         dev_err(dev, "Found button without gpio or irq\n");
 593                         return -EINVAL;
 594                 }
 595
 596                 bdata->irq = button->irq;
 597
 598                 if (button->type && button->type != EV_KEY) {
 599                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 600                         return -EINVAL;
 601                 }
 602
 603                 bdata->release_delay = button->debounce_interval;
 604                 timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
 605
 606                 isr = gpio_keys_irq_isr;
 607                 irqflags = 0;
 608
 609                 /*
 610                  * For IRQ buttons, there is no interrupt for release.
 611                  * So we don't need to reconfigure the trigger type for wakeup.
 612                  */
 613         }
 614
 615         bdata->code = &ddata->keymap[idx];
 616         *bdata->code = button->code;
 617         input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
 618
 619         /*
 620          * Install custom action to cancel release timer and
 621          * workqueue item.
 622          */
 623         error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
 624         if (error) {
 625                 dev_err(dev, "failed to register quiesce action, error: %d\n",
 626                         error);
 627                 return error;
 628         }
 629
 630         /*
 631          * If platform has specified that the button can be disabled,
 632          * we don't want it to share the interrupt line.
 633          */
 634         if (!button->can_disable)
 635                 irqflags |= IRQF_SHARED;
 636
 637         error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
 638                                              desc, bdata);
 639         if (error < 0) {
 640                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 641                         bdata->irq, error);
 642                 return error;
 643         }
 644
 645         return 0;
 646 }
 647
 648 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 649 {
 650         struct input_dev *input = ddata->input;
 651         int i;
 652
 653         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 654                 struct gpio_button_data *bdata = &ddata->data[i];
 655                 if (bdata->gpiod)
 656                         gpio_keys_gpio_report_event(bdata);
 657         }
 658         input_sync(input);
 659 }
 660
 661 static int gpio_keys_open(struct input_dev *input)
 662 {
 663         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 664         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 665         int error;
 666
 667         if (pdata->enable) {
 668                 error = pdata->enable(input->dev.parent);
 669                 if (error)
 670                         return error;
 671         }
 672
 673         /* Report current state of buttons that are connected to GPIOs */
 674         gpio_keys_report_state(ddata);
 675
 676         return 0;
 677 }
 678
 679 static void gpio_keys_close(struct input_dev *input)
 680 {
 681         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 682         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 683
 684         if (pdata->disable)
 685                 pdata->disable(input->dev.parent);
 686 }
 687
 688 /*
 689  * Handlers for alternative sources of platform_data
 690  */
 691
 692 /*
 693  * Translate properties into platform_data
 694  */
 695 static struct gpio_keys_platform_data *
 696 gpio_keys_get_devtree_pdata(struct device *dev)
 697 {
 698         struct gpio_keys_platform_data *pdata;
 699         struct gpio_keys_button *button;
 700         struct fwnode_handle *child;
 701         int nbuttons;
 702
 703         nbuttons = device_get_child_node_count(dev);
 704         if (nbuttons == 0)
 705                 return ERR_PTR(-ENODEV);
 706
 707         pdata = devm_kzalloc(dev,
 708                              sizeof(*pdata) + nbuttons * sizeof(*button),
 709                              GFP_KERNEL);
 710         if (!pdata)
 711                 return ERR_PTR(-ENOMEM);
 712
 713         button = (struct gpio_keys_button *)(pdata + 1);
 714
 715         pdata->buttons = button;
 716         pdata->nbuttons = nbuttons;
 717
 718         pdata->rep = device_property_read_bool(dev, "autorepeat");
 719
 720         device_property_read_string(dev, "label", &pdata->name);
 721
 722         device_for_each_child_node(dev, child) {
 723                 if (is_of_node(child))
 724                         button->irq =
 725                                 irq_of_parse_and_map(to_of_node(child), 0);
 726
 727                 if (fwnode_property_read_u32(child, "linux,code",
 728                                              &button->code)) {
 729                         dev_err(dev, "Button without keycode\n");
 730                         fwnode_handle_put(child);
 731                         return ERR_PTR(-EINVAL);
 732                 }
 733
 734                 fwnode_property_read_string(child, "label", &button->desc);
 735
 736                 if (fwnode_property_read_u32(child, "linux,input-type",
 737                                              &button->type))
 738                         button->type = EV_KEY;
 739
 740                 button->wakeup =
 741                         fwnode_property_read_bool(child, "wakeup-source") ||
 742                         /* legacy name */
 743                         fwnode_property_read_bool(child, "gpio-key,wakeup");
 744
 745                 fwnode_property_read_u32(child, "wakeup-event-action",
 746                                          &button->wakeup_event_action);
 747
 748                 button->can_disable =
 749                         fwnode_property_read_bool(child, "linux,can-disable");
 750
 751                 if (fwnode_property_read_u32(child, "debounce-interval",
 752                                          &button->debounce_interval))
 753                         button->debounce_interval = 5;
 754
 755                 button++;
 756         }
 757
 758         return pdata;
 759 }
 760
 761 static const struct of_device_id gpio_keys_of_match[] = {
 762         { .compatible = "gpio-keys", },
 763         { },
 764 };
 765 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 766
 767 static int gpio_keys_probe(struct platform_device *pdev)
 768 {
 769         struct device *dev = &pdev->dev;
 770         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 771         struct fwnode_handle *child = NULL;
 772         struct gpio_keys_drvdata *ddata;
 773         struct input_dev *input;
 774         int i, error;
 775         int wakeup = 0;
 776
 777         if (!pdata) {
 778                 pdata = gpio_keys_get_devtree_pdata(dev);
 779                 if (IS_ERR(pdata))
 780                         return PTR_ERR(pdata);
 781         }
 782
 783         ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
 784                              GFP_KERNEL);
 785         if (!ddata) {
 786                 dev_err(dev, "failed to allocate state\n");
 787                 return -ENOMEM;
 788         }
 789
 790         ddata->keymap = devm_kcalloc(dev,
 791                                      pdata->nbuttons, sizeof(ddata->keymap[0]),
 792                                      GFP_KERNEL);
 793         if (!ddata->keymap)
 794                 return -ENOMEM;
 795
 796         input = devm_input_allocate_device(dev);
 797         if (!input) {
 798                 dev_err(dev, "failed to allocate input device\n");
 799                 return -ENOMEM;
 800         }
 801
 802         ddata->pdata = pdata;
 803         ddata->input = input;
 804         mutex_init(&ddata->disable_lock);
 805
 806         platform_set_drvdata(pdev, ddata);
 807         input_set_drvdata(input, ddata);
 808
 809         input->name = pdata->name ? : pdev->name;
 810         input->phys = "gpio-keys/input0";
 811         input->dev.parent = dev;
 812         input->open = gpio_keys_open;
 813         input->close = gpio_keys_close;
 814
 815         input->id.bustype = BUS_HOST;
 816         input->id.vendor = 0x0001;
 817         input->id.product = 0x0001;
 818         input->id.version = 0x0100;
 819
 820         input->keycode = ddata->keymap;
 821         input->keycodesize = sizeof(ddata->keymap[0]);
 822         input->keycodemax = pdata->nbuttons;
 823
 824         /* Enable auto repeat feature of Linux input subsystem */
 825         if (pdata->rep)
 826                 __set_bit(EV_REP, input->evbit);
 827
 828         for (i = 0; i < pdata->nbuttons; i++) {
 829                 const struct gpio_keys_button *button = &pdata->buttons[i];
 830
 831                 if (!dev_get_platdata(dev)) {
 832                         child = device_get_next_child_node(dev, child);
 833                         if (!child) {
 834                                 dev_err(dev,
 835                                         "missing child device node for entry %d\n",
 836                                         i);
 837                                 return -EINVAL;
 838                         }
 839                 }
 840
 841                 error = gpio_keys_setup_key(pdev, input, ddata,
 842                                             button, i, child);
 843                 if (error) {
 844                         fwnode_handle_put(child);
 845                         return error;
 846                 }
 847
 848                 if (button->wakeup)
 849                         wakeup = 1;
 850         }
 851
 852         fwnode_handle_put(child);
 853
 854         error = devm_device_add_group(dev, &gpio_keys_attr_group);
 855         if (error) {
 856                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
 857                         error);
 858                 return error;
 859         }
 860
 861         error = input_register_device(input);
 862         if (error) {
 863                 dev_err(dev, "Unable to register input device, error: %d\n",
 864                         error);
 865                 return error;
 866         }
 867
 868         device_init_wakeup(dev, wakeup);
 869
 870         return 0;
 871 }
 872
 873 static int __maybe_unused
 874 gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
 875 {
 876         int error;
 877
 878         error = enable_irq_wake(bdata->irq);
 879         if (error) {
 880                 dev_err(bdata->input->dev.parent,
 881                         "failed to configure IRQ %d as wakeup source: %d\n",
 882                         bdata->irq, error);
 883                 return error;
 884         }
 885
 886         if (bdata->wakeup_trigger_type) {
 887                 error = irq_set_irq_type(bdata->irq,
 888                                          bdata->wakeup_trigger_type);
 889                 if (error) {
 890                         dev_err(bdata->input->dev.parent,
 891                                 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
 892                                 bdata->wakeup_trigger_type, bdata->irq, error);
 893                         disable_irq_wake(bdata->irq);
 894                         return error;
 895                 }
 896         }
 897
 898         return 0;
 899 }
 900
 901 static void __maybe_unused
 902 gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
 903 {
 904         int error;
 905
 906         /*
 907          * The trigger type is always both edges for gpio-based keys and we do
 908          * not support changing wakeup trigger for interrupt-based keys.
 909          */
 910         if (bdata->wakeup_trigger_type) {
 911                 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
 912                 if (error)
 913                         dev_warn(bdata->input->dev.parent,
 914                                  "failed to restore interrupt trigger for IRQ %d: %d\n",
 915                                  bdata->irq, error);
 916         }
 917
 918         error = disable_irq_wake(bdata->irq);
 919         if (error)
 920                 dev_warn(bdata->input->dev.parent,
 921                          "failed to disable IRQ %d as wake source: %d\n",
 922                          bdata->irq, error);
 923 }
 924
 925 static int __maybe_unused
 926 gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
 927 {
 928         struct gpio_button_data *bdata;
 929         int error;
 930         int i;
 931
 932         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 933                 bdata = &ddata->data[i];
 934                 if (bdata->button->wakeup) {
 935                         error = gpio_keys_button_enable_wakeup(bdata);
 936                         if (error)
 937                                 goto err_out;
 938                 }
 939                 bdata->suspended = true;
 940         }
 941
 942         return 0;
 943
 944 err_out:
 945         while (i--) {
 946                 bdata = &ddata->data[i];
 947                 if (bdata->button->wakeup)
 948                         gpio_keys_button_disable_wakeup(bdata);
 949                 bdata->suspended = false;
 950         }
 951
 952         return error;
 953 }
 954
 955 static void __maybe_unused
 956 gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
 957 {
 958         struct gpio_button_data *bdata;
 959         int i;
 960
 961         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 962                 bdata = &ddata->data[i];
 963                 bdata->suspended = false;
 964                 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
 965                         gpio_keys_button_disable_wakeup(bdata);
 966         }
 967 }
 968
 969 static int __maybe_unused gpio_keys_suspend(struct device *dev)
 970 {
 971         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 972         struct input_dev *input = ddata->input;
 973         int error;
 974
 975         if (device_may_wakeup(dev)) {
 976                 error = gpio_keys_enable_wakeup(ddata);
 977                 if (error)
 978                         return error;
 979         } else {
 980                 mutex_lock(&input->mutex);
 981                 if (input->users)
 982                         gpio_keys_close(input);
 983                 mutex_unlock(&input->mutex);
 984         }
 985
 986         return 0;
 987 }
 988
 989 static int __maybe_unused gpio_keys_resume(struct device *dev)
 990 {
 991         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 992         struct input_dev *input = ddata->input;
 993         int error = 0;
 994
 995         if (device_may_wakeup(dev)) {
 996                 gpio_keys_disable_wakeup(ddata);
 997         } else {
 998                 mutex_lock(&input->mutex);
 999                 if (input->users)
1000                         error = gpio_keys_open(input);
1001                 mutex_unlock(&input->mutex);
1002         }
1003
1004         if (error)
1005                 return error;
1006
1007         gpio_keys_report_state(ddata);
1008         return 0;
1009 }
1010
1011 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1012
1013 static void gpio_keys_shutdown(struct platform_device *pdev)
1014 {
1015         int ret;
1016
1017         ret = gpio_keys_suspend(&pdev->dev);
1018         if (ret)
1019                 dev_err(&pdev->dev, "failed to shutdown\n");
1020 }
1021
1022 static struct platform_driver gpio_keys_device_driver = {
1023         .probe          = gpio_keys_probe,
1024         .shutdown       = gpio_keys_shutdown,
1025         .driver         = {
1026                 .name   = "gpio-keys",
1027                 .pm     = &gpio_keys_pm_ops,
1028                 .of_match_table = gpio_keys_of_match,
1029         }
1030 };
1031
1032 static int __init gpio_keys_init(void)
1033 {
1034         return platform_driver_register(&gpio_keys_device_driver);
1035 }
1036
1037 static void __exit gpio_keys_exit(void)
1038 {
1039         platform_driver_unregister(&gpio_keys_device_driver);
1040 }
1041
1042 late_initcall(gpio_keys_init);
1043 module_exit(gpio_keys_exit);
1044
1045 MODULE_LICENSE("GPL");
1046 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1047 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1048 MODULE_ALIAS("platform:gpio-keys");