drivers/input/keyboard/gpio_keys.c

   1 /*
   2  * Driver for keys on GPIO lines capable of generating interrupts.
   3  *
   4  * Copyright 2005 Phil Blundell
   5  * Copyright 2010, 2011 David Jander <david@protonic.nl>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13
  14 #include <linux/init.h>
  15 #include <linux/fs.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/irq.h>
  18 #include <linux/sched.h>
  19 #include <linux/pm.h>
  20 #include <linux/slab.h>
  21 #include <linux/sysctl.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/delay.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/input.h>
  26 #include <linux/gpio_keys.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/gpio.h>
  29 #include <linux/gpio/consumer.h>
  30 #include <linux/of.h>
  31 #include <linux/of_irq.h>
  32 #include <linux/spinlock.h>
  33
  34 struct gpio_button_data {
  35         const struct gpio_keys_button *button;
  36         struct input_dev *input;
  37         struct gpio_desc *gpiod;
  38
  39         unsigned short *code;
  40
  41         struct timer_list release_timer;
  42         unsigned int release_delay;     /* in msecs, for IRQ-only buttons */
  43
  44         struct delayed_work work;
  45         unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
  46
  47         unsigned int irq;
  48         spinlock_t lock;
  49         bool disabled;
  50         bool key_pressed;
  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 = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), 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         kfree(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 = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), 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         kfree(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 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                 pm_stay_awake(bdata->input->dev.parent);
 401
 402         mod_delayed_work(system_wq,
 403                          &bdata->work,
 404                          msecs_to_jiffies(bdata->software_debounce));
 405
 406         return IRQ_HANDLED;
 407 }
 408
 409 static void gpio_keys_irq_timer(unsigned long _data)
 410 {
 411         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
 412         struct input_dev *input = bdata->input;
 413         unsigned long flags;
 414
 415         spin_lock_irqsave(&bdata->lock, flags);
 416         if (bdata->key_pressed) {
 417                 input_event(input, EV_KEY, *bdata->code, 0);
 418                 input_sync(input);
 419                 bdata->key_pressed = false;
 420         }
 421         spin_unlock_irqrestore(&bdata->lock, flags);
 422 }
 423
 424 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
 425 {
 426         struct gpio_button_data *bdata = dev_id;
 427         struct input_dev *input = bdata->input;
 428         unsigned long flags;
 429
 430         BUG_ON(irq != bdata->irq);
 431
 432         spin_lock_irqsave(&bdata->lock, flags);
 433
 434         if (!bdata->key_pressed) {
 435                 if (bdata->button->wakeup)
 436                         pm_wakeup_event(bdata->input->dev.parent, 0);
 437
 438                 input_event(input, EV_KEY, *bdata->code, 1);
 439                 input_sync(input);
 440
 441                 if (!bdata->release_delay) {
 442                         input_event(input, EV_KEY, *bdata->code, 0);
 443                         input_sync(input);
 444                         goto out;
 445                 }
 446
 447                 bdata->key_pressed = true;
 448         }
 449
 450         if (bdata->release_delay)
 451                 mod_timer(&bdata->release_timer,
 452                         jiffies + msecs_to_jiffies(bdata->release_delay));
 453 out:
 454         spin_unlock_irqrestore(&bdata->lock, flags);
 455         return IRQ_HANDLED;
 456 }
 457
 458 static void gpio_keys_quiesce_key(void *data)
 459 {
 460         struct gpio_button_data *bdata = data;
 461
 462         if (bdata->gpiod)
 463                 cancel_delayed_work_sync(&bdata->work);
 464         else
 465                 del_timer_sync(&bdata->release_timer);
 466 }
 467
 468 static int gpio_keys_setup_key(struct platform_device *pdev,
 469                                 struct input_dev *input,
 470                                 struct gpio_keys_drvdata *ddata,
 471                                 const struct gpio_keys_button *button,
 472                                 int idx,
 473                                 struct fwnode_handle *child)
 474 {
 475         const char *desc = button->desc ? button->desc : "gpio_keys";
 476         struct device *dev = &pdev->dev;
 477         struct gpio_button_data *bdata = &ddata->data[idx];
 478         irq_handler_t isr;
 479         unsigned long irqflags;
 480         int irq;
 481         int error;
 482
 483         bdata->input = input;
 484         bdata->button = button;
 485         spin_lock_init(&bdata->lock);
 486
 487         if (child) {
 488                 bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL,
 489                                                                 child,
 490                                                                 GPIOD_IN,
 491                                                                 desc);
 492                 if (IS_ERR(bdata->gpiod)) {
 493                         error = PTR_ERR(bdata->gpiod);
 494                         if (error == -ENOENT) {
 495                                 /*
 496                                  * GPIO is optional, we may be dealing with
 497                                  * purely interrupt-driven setup.
 498                                  */
 499                                 bdata->gpiod = NULL;
 500                         } else {
 501                                 if (error != -EPROBE_DEFER)
 502                                         dev_err(dev, "failed to get gpio: %d\n",
 503                                                 error);
 504                                 return error;
 505                         }
 506                 }
 507         } else if (gpio_is_valid(button->gpio)) {
 508                 /*
 509                  * Legacy GPIO number, so request the GPIO here and
 510                  * convert it to descriptor.
 511                  */
 512                 unsigned flags = GPIOF_IN;
 513
 514                 if (button->active_low)
 515                         flags |= GPIOF_ACTIVE_LOW;
 516
 517                 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
 518                 if (error < 0) {
 519                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
 520                                 button->gpio, error);
 521                         return error;
 522                 }
 523
 524                 bdata->gpiod = gpio_to_desc(button->gpio);
 525                 if (!bdata->gpiod)
 526                         return -EINVAL;
 527         }
 528
 529         if (bdata->gpiod) {
 530                 if (button->debounce_interval) {
 531                         error = gpiod_set_debounce(bdata->gpiod,
 532                                         button->debounce_interval * 1000);
 533                         /* use timer if gpiolib doesn't provide debounce */
 534                         if (error < 0)
 535                                 bdata->software_debounce =
 536                                                 button->debounce_interval;
 537                 }
 538
 539                 if (button->irq) {
 540                         bdata->irq = button->irq;
 541                 } else {
 542                         irq = gpiod_to_irq(bdata->gpiod);
 543                         if (irq < 0) {
 544                                 error = irq;
 545                                 dev_err(dev,
 546                                         "Unable to get irq number for GPIO %d, error %d\n",
 547                                         button->gpio, error);
 548                                 return error;
 549                         }
 550                         bdata->irq = irq;
 551                 }
 552
 553                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
 554
 555                 isr = gpio_keys_gpio_isr;
 556                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 557
 558         } else {
 559                 if (!button->irq) {
 560                         dev_err(dev, "Found button without gpio or irq\n");
 561                         return -EINVAL;
 562                 }
 563
 564                 bdata->irq = button->irq;
 565
 566                 if (button->type && button->type != EV_KEY) {
 567                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 568                         return -EINVAL;
 569                 }
 570
 571                 bdata->release_delay = button->debounce_interval;
 572                 setup_timer(&bdata->release_timer,
 573                             gpio_keys_irq_timer, (unsigned long)bdata);
 574
 575                 isr = gpio_keys_irq_isr;
 576                 irqflags = 0;
 577         }
 578
 579         bdata->code = &ddata->keymap[idx];
 580         *bdata->code = button->code;
 581         input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
 582
 583         /*
 584          * Install custom action to cancel release timer and
 585          * workqueue item.
 586          */
 587         error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
 588         if (error) {
 589                 dev_err(dev, "failed to register quiesce action, error: %d\n",
 590                         error);
 591                 return error;
 592         }
 593
 594         /*
 595          * If platform has specified that the button can be disabled,
 596          * we don't want it to share the interrupt line.
 597          */
 598         if (!button->can_disable)
 599                 irqflags |= IRQF_SHARED;
 600
 601         error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
 602                                              desc, bdata);
 603         if (error < 0) {
 604                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 605                         bdata->irq, error);
 606                 return error;
 607         }
 608
 609         return 0;
 610 }
 611
 612 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 613 {
 614         struct input_dev *input = ddata->input;
 615         int i;
 616
 617         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 618                 struct gpio_button_data *bdata = &ddata->data[i];
 619                 if (bdata->gpiod)
 620                         gpio_keys_gpio_report_event(bdata);
 621         }
 622         input_sync(input);
 623 }
 624
 625 static int gpio_keys_open(struct input_dev *input)
 626 {
 627         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 628         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 629         int error;
 630
 631         if (pdata->enable) {
 632                 error = pdata->enable(input->dev.parent);
 633                 if (error)
 634                         return error;
 635         }
 636
 637         /* Report current state of buttons that are connected to GPIOs */
 638         gpio_keys_report_state(ddata);
 639
 640         return 0;
 641 }
 642
 643 static void gpio_keys_close(struct input_dev *input)
 644 {
 645         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 646         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 647
 648         if (pdata->disable)
 649                 pdata->disable(input->dev.parent);
 650 }
 651
 652 /*
 653  * Handlers for alternative sources of platform_data
 654  */
 655
 656 /*
 657  * Translate properties into platform_data
 658  */
 659 static struct gpio_keys_platform_data *
 660 gpio_keys_get_devtree_pdata(struct device *dev)
 661 {
 662         struct gpio_keys_platform_data *pdata;
 663         struct gpio_keys_button *button;
 664         struct fwnode_handle *child;
 665         int nbuttons;
 666
 667         nbuttons = device_get_child_node_count(dev);
 668         if (nbuttons == 0)
 669                 return ERR_PTR(-ENODEV);
 670
 671         pdata = devm_kzalloc(dev,
 672                              sizeof(*pdata) + nbuttons * sizeof(*button),
 673                              GFP_KERNEL);
 674         if (!pdata)
 675                 return ERR_PTR(-ENOMEM);
 676
 677         button = (struct gpio_keys_button *)(pdata + 1);
 678
 679         pdata->buttons = button;
 680         pdata->nbuttons = nbuttons;
 681
 682         pdata->rep = device_property_read_bool(dev, "autorepeat");
 683
 684         device_property_read_string(dev, "label", &pdata->name);
 685
 686         device_for_each_child_node(dev, child) {
 687                 if (is_of_node(child))
 688                         button->irq =
 689                                 irq_of_parse_and_map(to_of_node(child), 0);
 690
 691                 if (fwnode_property_read_u32(child, "linux,code",
 692                                              &button->code)) {
 693                         dev_err(dev, "Button without keycode\n");
 694                         fwnode_handle_put(child);
 695                         return ERR_PTR(-EINVAL);
 696                 }
 697
 698                 fwnode_property_read_string(child, "label", &button->desc);
 699
 700                 if (fwnode_property_read_u32(child, "linux,input-type",
 701                                              &button->type))
 702                         button->type = EV_KEY;
 703
 704                 button->wakeup =
 705                         fwnode_property_read_bool(child, "wakeup-source") ||
 706                         /* legacy name */
 707                         fwnode_property_read_bool(child, "gpio-key,wakeup");
 708
 709                 button->can_disable =
 710                         fwnode_property_read_bool(child, "linux,can-disable");
 711
 712                 if (fwnode_property_read_u32(child, "debounce-interval",
 713                                          &button->debounce_interval))
 714                         button->debounce_interval = 5;
 715
 716                 button++;
 717         }
 718
 719         return pdata;
 720 }
 721
 722 static const struct of_device_id gpio_keys_of_match[] = {
 723         { .compatible = "gpio-keys", },
 724         { },
 725 };
 726 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 727
 728 static int gpio_keys_probe(struct platform_device *pdev)
 729 {
 730         struct device *dev = &pdev->dev;
 731         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 732         struct fwnode_handle *child = NULL;
 733         struct gpio_keys_drvdata *ddata;
 734         struct input_dev *input;
 735         size_t size;
 736         int i, error;
 737         int wakeup = 0;
 738
 739         if (!pdata) {
 740                 pdata = gpio_keys_get_devtree_pdata(dev);
 741                 if (IS_ERR(pdata))
 742                         return PTR_ERR(pdata);
 743         }
 744
 745         size = sizeof(struct gpio_keys_drvdata) +
 746                         pdata->nbuttons * sizeof(struct gpio_button_data);
 747         ddata = devm_kzalloc(dev, size, GFP_KERNEL);
 748         if (!ddata) {
 749                 dev_err(dev, "failed to allocate state\n");
 750                 return -ENOMEM;
 751         }
 752
 753         ddata->keymap = devm_kcalloc(dev,
 754                                      pdata->nbuttons, sizeof(ddata->keymap[0]),
 755                                      GFP_KERNEL);
 756         if (!ddata->keymap)
 757                 return -ENOMEM;
 758
 759         input = devm_input_allocate_device(dev);
 760         if (!input) {
 761                 dev_err(dev, "failed to allocate input device\n");
 762                 return -ENOMEM;
 763         }
 764
 765         ddata->pdata = pdata;
 766         ddata->input = input;
 767         mutex_init(&ddata->disable_lock);
 768
 769         platform_set_drvdata(pdev, ddata);
 770         input_set_drvdata(input, ddata);
 771
 772         input->name = pdata->name ? : pdev->name;
 773         input->phys = "gpio-keys/input0";
 774         input->dev.parent = dev;
 775         input->open = gpio_keys_open;
 776         input->close = gpio_keys_close;
 777
 778         input->id.bustype = BUS_HOST;
 779         input->id.vendor = 0x0001;
 780         input->id.product = 0x0001;
 781         input->id.version = 0x0100;
 782
 783         input->keycode = ddata->keymap;
 784         input->keycodesize = sizeof(ddata->keymap[0]);
 785         input->keycodemax = pdata->nbuttons;
 786
 787         /* Enable auto repeat feature of Linux input subsystem */
 788         if (pdata->rep)
 789                 __set_bit(EV_REP, input->evbit);
 790
 791         for (i = 0; i < pdata->nbuttons; i++) {
 792                 const struct gpio_keys_button *button = &pdata->buttons[i];
 793
 794                 if (!dev_get_platdata(dev)) {
 795                         child = device_get_next_child_node(dev, child);
 796                         if (!child) {
 797                                 dev_err(dev,
 798                                         "missing child device node for entry %d\n",
 799                                         i);
 800                                 return -EINVAL;
 801                         }
 802                 }
 803
 804                 error = gpio_keys_setup_key(pdev, input, ddata,
 805                                             button, i, child);
 806                 if (error) {
 807                         fwnode_handle_put(child);
 808                         return error;
 809                 }
 810
 811                 if (button->wakeup)
 812                         wakeup = 1;
 813         }
 814
 815         fwnode_handle_put(child);
 816
 817         error = sysfs_create_group(&dev->kobj, &gpio_keys_attr_group);
 818         if (error) {
 819                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
 820                         error);
 821                 return error;
 822         }
 823
 824         error = input_register_device(input);
 825         if (error) {
 826                 dev_err(dev, "Unable to register input device, error: %d\n",
 827                         error);
 828                 goto err_remove_group;
 829         }
 830
 831         device_init_wakeup(dev, wakeup);
 832
 833         return 0;
 834
 835 err_remove_group:
 836         sysfs_remove_group(&dev->kobj, &gpio_keys_attr_group);
 837         return error;
 838 }
 839
 840 static int gpio_keys_remove(struct platform_device *pdev)
 841 {
 842         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 843
 844         return 0;
 845 }
 846
 847 static int __maybe_unused gpio_keys_suspend(struct device *dev)
 848 {
 849         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 850         struct input_dev *input = ddata->input;
 851         int i;
 852
 853         if (device_may_wakeup(dev)) {
 854                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
 855                         struct gpio_button_data *bdata = &ddata->data[i];
 856                         if (bdata->button->wakeup)
 857                                 enable_irq_wake(bdata->irq);
 858                 }
 859         } else {
 860                 mutex_lock(&input->mutex);
 861                 if (input->users)
 862                         gpio_keys_close(input);
 863                 mutex_unlock(&input->mutex);
 864         }
 865
 866         return 0;
 867 }
 868
 869 static int __maybe_unused gpio_keys_resume(struct device *dev)
 870 {
 871         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 872         struct input_dev *input = ddata->input;
 873         int error = 0;
 874         int i;
 875
 876         if (device_may_wakeup(dev)) {
 877                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
 878                         struct gpio_button_data *bdata = &ddata->data[i];
 879                         if (bdata->button->wakeup)
 880                                 disable_irq_wake(bdata->irq);
 881                 }
 882         } else {
 883                 mutex_lock(&input->mutex);
 884                 if (input->users)
 885                         error = gpio_keys_open(input);
 886                 mutex_unlock(&input->mutex);
 887         }
 888
 889         if (error)
 890                 return error;
 891
 892         gpio_keys_report_state(ddata);
 893         return 0;
 894 }
 895
 896 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
 897
 898 static struct platform_driver gpio_keys_device_driver = {
 899         .probe          = gpio_keys_probe,
 900         .remove         = gpio_keys_remove,
 901         .driver         = {
 902                 .name   = "gpio-keys",
 903                 .pm     = &gpio_keys_pm_ops,
 904                 .of_match_table = gpio_keys_of_match,
 905         }
 906 };
 907
 908 static int __init gpio_keys_init(void)
 909 {
 910         return platform_driver_register(&gpio_keys_device_driver);
 911 }
 912
 913 static void __exit gpio_keys_exit(void)
 914 {
 915         platform_driver_unregister(&gpio_keys_device_driver);
 916 }
 917
 918 late_initcall(gpio_keys_init);
 919 module_exit(gpio_keys_exit);
 920
 921 MODULE_LICENSE("GPL");
 922 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 923 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
 924 MODULE_ALIAS("platform:gpio-keys");