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/of.h>
  30 #include <linux/of_platform.h>
  31 #include <linux/of_gpio.h>
  32 #include <linux/of_irq.h>
  33 #include <linux/spinlock.h>
  34
  35 struct gpio_button_data {
  36         const struct gpio_keys_button *button;
  37         struct input_dev *input;
  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         spinlock_t lock;
  47         bool disabled;
  48         bool key_pressed;
  49 };
  50
  51 struct gpio_keys_drvdata {
  52         const struct gpio_keys_platform_data *pdata;
  53         struct input_dev *input;
  54         struct mutex disable_lock;
  55         struct gpio_button_data data[0];
  56 };
  57
  58 /*
  59  * SYSFS interface for enabling/disabling keys and switches:
  60  *
  61  * There are 4 attributes under /sys/devices/platform/gpio-keys/
  62  *      keys [ro]              - bitmap of keys (EV_KEY) which can be
  63  *                               disabled
  64  *      switches [ro]          - bitmap of switches (EV_SW) which can be
  65  *                               disabled
  66  *      disabled_keys [rw]     - bitmap of keys currently disabled
  67  *      disabled_switches [rw] - bitmap of switches currently disabled
  68  *
  69  * Userland can change these values and hence disable event generation
  70  * for each key (or switch). Disabling a key means its interrupt line
  71  * is disabled.
  72  *
  73  * For example, if we have following switches set up as gpio-keys:
  74  *      SW_DOCK = 5
  75  *      SW_CAMERA_LENS_COVER = 9
  76  *      SW_KEYPAD_SLIDE = 10
  77  *      SW_FRONT_PROXIMITY = 11
  78  * This is read from switches:
  79  *      11-9,5
  80  * Next we want to disable proximity (11) and dock (5), we write:
  81  *      11,5
  82  * to file disabled_switches. Now proximity and dock IRQs are disabled.
  83  * This can be verified by reading the file disabled_switches:
  84  *      11,5
  85  * If we now want to enable proximity (11) switch we write:
  86  *      5
  87  * to disabled_switches.
  88  *
  89  * We can disable only those keys which don't allow sharing the irq.
  90  */
  91
  92 /**
  93  * get_n_events_by_type() - returns maximum number of events per @type
  94  * @type: type of button (%EV_KEY, %EV_SW)
  95  *
  96  * Return value of this function can be used to allocate bitmap
  97  * large enough to hold all bits for given type.
  98  */
  99 static int get_n_events_by_type(int type)
 100 {
 101         BUG_ON(type != EV_SW && type != EV_KEY);
 102
 103         return (type == EV_KEY) ? KEY_CNT : SW_CNT;
 104 }
 105
 106 /**
 107  * get_bm_events_by_type() - returns bitmap of supported events per @type
 108  * @input: input device from which bitmap is retrieved
 109  * @type: type of button (%EV_KEY, %EV_SW)
 110  *
 111  * Return value of this function can be used to allocate bitmap
 112  * large enough to hold all bits for given type.
 113  */
 114 static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
 115                                                   int type)
 116 {
 117         BUG_ON(type != EV_SW && type != EV_KEY);
 118
 119         return (type == EV_KEY) ? dev->keybit : dev->swbit;
 120 }
 121
 122 /**
 123  * gpio_keys_disable_button() - disables given GPIO button
 124  * @bdata: button data for button to be disabled
 125  *
 126  * Disables button pointed by @bdata. This is done by masking
 127  * IRQ line. After this function is called, button won't generate
 128  * input events anymore. Note that one can only disable buttons
 129  * that don't share IRQs.
 130  *
 131  * Make sure that @bdata->disable_lock is locked when entering
 132  * this function to avoid races when concurrent threads are
 133  * disabling buttons at the same time.
 134  */
 135 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
 136 {
 137         if (!bdata->disabled) {
 138                 /*
 139                  * Disable IRQ and associated timer/work structure.
 140                  */
 141                 disable_irq(bdata->irq);
 142
 143                 if (gpio_is_valid(bdata->button->gpio))
 144                         cancel_delayed_work_sync(&bdata->work);
 145                 else
 146                         del_timer_sync(&bdata->release_timer);
 147
 148                 bdata->disabled = true;
 149         }
 150 }
 151
 152 /**
 153  * gpio_keys_enable_button() - enables given GPIO button
 154  * @bdata: button data for button to be disabled
 155  *
 156  * Enables given button pointed by @bdata.
 157  *
 158  * Make sure that @bdata->disable_lock is locked when entering
 159  * this function to avoid races with concurrent threads trying
 160  * to enable the same button at the same time.
 161  */
 162 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
 163 {
 164         if (bdata->disabled) {
 165                 enable_irq(bdata->irq);
 166                 bdata->disabled = false;
 167         }
 168 }
 169
 170 /**
 171  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
 172  * @ddata: pointer to drvdata
 173  * @buf: buffer where stringified bitmap is written
 174  * @type: button type (%EV_KEY, %EV_SW)
 175  * @only_disabled: does caller want only those buttons that are
 176  *                 currently disabled or all buttons that can be
 177  *                 disabled
 178  *
 179  * This function writes buttons that can be disabled to @buf. If
 180  * @only_disabled is true, then @buf contains only those buttons
 181  * that are currently disabled. Returns 0 on success or negative
 182  * errno on failure.
 183  */
 184 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
 185                                           char *buf, unsigned int type,
 186                                           bool only_disabled)
 187 {
 188         int n_events = get_n_events_by_type(type);
 189         unsigned long *bits;
 190         ssize_t ret;
 191         int i;
 192
 193         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
 194         if (!bits)
 195                 return -ENOMEM;
 196
 197         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 198                 struct gpio_button_data *bdata = &ddata->data[i];
 199
 200                 if (bdata->button->type != type)
 201                         continue;
 202
 203                 if (only_disabled && !bdata->disabled)
 204                         continue;
 205
 206                 __set_bit(bdata->button->code, bits);
 207         }
 208
 209         ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
 210         buf[ret++] = '\n';
 211         buf[ret] = '\0';
 212
 213         kfree(bits);
 214
 215         return ret;
 216 }
 217
 218 /**
 219  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
 220  * @ddata: pointer to drvdata
 221  * @buf: buffer from userspace that contains stringified bitmap
 222  * @type: button type (%EV_KEY, %EV_SW)
 223  *
 224  * This function parses stringified bitmap from @buf and disables/enables
 225  * GPIO buttons accordingly. Returns 0 on success and negative error
 226  * on failure.
 227  */
 228 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 229                                            const char *buf, unsigned int type)
 230 {
 231         int n_events = get_n_events_by_type(type);
 232         const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
 233         unsigned long *bits;
 234         ssize_t error;
 235         int i;
 236
 237         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
 238         if (!bits)
 239                 return -ENOMEM;
 240
 241         error = bitmap_parselist(buf, bits, n_events);
 242         if (error)
 243                 goto out;
 244
 245         /* First validate */
 246         if (!bitmap_subset(bits, bitmap, n_events)) {
 247                 error = -EINVAL;
 248                 goto out;
 249         }
 250
 251         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 252                 struct gpio_button_data *bdata = &ddata->data[i];
 253
 254                 if (bdata->button->type != type)
 255                         continue;
 256
 257                 if (test_bit(bdata->button->code, bits) &&
 258                     !bdata->button->can_disable) {
 259                         error = -EINVAL;
 260                         goto out;
 261                 }
 262         }
 263
 264         mutex_lock(&ddata->disable_lock);
 265
 266         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 267                 struct gpio_button_data *bdata = &ddata->data[i];
 268
 269                 if (bdata->button->type != type)
 270                         continue;
 271
 272                 if (test_bit(bdata->button->code, bits))
 273                         gpio_keys_disable_button(bdata);
 274                 else
 275                         gpio_keys_enable_button(bdata);
 276         }
 277
 278         mutex_unlock(&ddata->disable_lock);
 279
 280 out:
 281         kfree(bits);
 282         return error;
 283 }
 284
 285 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
 286 static ssize_t gpio_keys_show_##name(struct device *dev,                \
 287                                      struct device_attribute *attr,     \
 288                                      char *buf)                         \
 289 {                                                                       \
 290         struct platform_device *pdev = to_platform_device(dev);         \
 291         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 292                                                                         \
 293         return gpio_keys_attr_show_helper(ddata, buf,                   \
 294                                           type, only_disabled);         \
 295 }
 296
 297 ATTR_SHOW_FN(keys, EV_KEY, false);
 298 ATTR_SHOW_FN(switches, EV_SW, false);
 299 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
 300 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
 301
 302 /*
 303  * ATTRIBUTES:
 304  *
 305  * /sys/devices/platform/gpio-keys/keys [ro]
 306  * /sys/devices/platform/gpio-keys/switches [ro]
 307  */
 308 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
 309 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
 310
 311 #define ATTR_STORE_FN(name, type)                                       \
 312 static ssize_t gpio_keys_store_##name(struct device *dev,               \
 313                                       struct device_attribute *attr,    \
 314                                       const char *buf,                  \
 315                                       size_t count)                     \
 316 {                                                                       \
 317         struct platform_device *pdev = to_platform_device(dev);         \
 318         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 319         ssize_t error;                                                  \
 320                                                                         \
 321         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
 322         if (error)                                                      \
 323                 return error;                                           \
 324                                                                         \
 325         return count;                                                   \
 326 }
 327
 328 ATTR_STORE_FN(disabled_keys, EV_KEY);
 329 ATTR_STORE_FN(disabled_switches, EV_SW);
 330
 331 /*
 332  * ATTRIBUTES:
 333  *
 334  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
 335  * /sys/devices/platform/gpio-keys/disables_switches [rw]
 336  */
 337 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
 338                    gpio_keys_show_disabled_keys,
 339                    gpio_keys_store_disabled_keys);
 340 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
 341                    gpio_keys_show_disabled_switches,
 342                    gpio_keys_store_disabled_switches);
 343
 344 static struct attribute *gpio_keys_attrs[] = {
 345         &dev_attr_keys.attr,
 346         &dev_attr_switches.attr,
 347         &dev_attr_disabled_keys.attr,
 348         &dev_attr_disabled_switches.attr,
 349         NULL,
 350 };
 351
 352 static struct attribute_group gpio_keys_attr_group = {
 353         .attrs = gpio_keys_attrs,
 354 };
 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 = gpio_get_value_cansleep(button->gpio);
 362
 363         if (state < 0) {
 364                 dev_err(input->dev.parent, "failed to get gpio state\n");
 365                 return;
 366         }
 367
 368         state = (state ? 1 : 0) ^ button->active_low;
 369         if (type == EV_ABS) {
 370                 if (state)
 371                         input_event(input, type, button->code, button->value);
 372         } else {
 373                 input_event(input, type, button->code, !!state);
 374         }
 375         input_sync(input);
 376 }
 377
 378 static void gpio_keys_gpio_work_func(struct work_struct *work)
 379 {
 380         struct gpio_button_data *bdata =
 381                 container_of(work, struct gpio_button_data, work.work);
 382
 383         gpio_keys_gpio_report_event(bdata);
 384
 385         if (bdata->button->wakeup)
 386                 pm_relax(bdata->input->dev.parent);
 387 }
 388
 389 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
 390 {
 391         struct gpio_button_data *bdata = dev_id;
 392
 393         BUG_ON(irq != bdata->irq);
 394
 395         if (bdata->button->wakeup)
 396                 pm_stay_awake(bdata->input->dev.parent);
 397
 398         mod_delayed_work(system_wq,
 399                          &bdata->work,
 400                          msecs_to_jiffies(bdata->software_debounce));
 401
 402         return IRQ_HANDLED;
 403 }
 404
 405 static void gpio_keys_irq_timer(unsigned long _data)
 406 {
 407         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
 408         struct input_dev *input = bdata->input;
 409         unsigned long flags;
 410
 411         spin_lock_irqsave(&bdata->lock, flags);
 412         if (bdata->key_pressed) {
 413                 input_event(input, EV_KEY, bdata->button->code, 0);
 414                 input_sync(input);
 415                 bdata->key_pressed = false;
 416         }
 417         spin_unlock_irqrestore(&bdata->lock, flags);
 418 }
 419
 420 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
 421 {
 422         struct gpio_button_data *bdata = dev_id;
 423         const struct gpio_keys_button *button = bdata->button;
 424         struct input_dev *input = bdata->input;
 425         unsigned long flags;
 426
 427         BUG_ON(irq != bdata->irq);
 428
 429         spin_lock_irqsave(&bdata->lock, flags);
 430
 431         if (!bdata->key_pressed) {
 432                 if (bdata->button->wakeup)
 433                         pm_wakeup_event(bdata->input->dev.parent, 0);
 434
 435                 input_event(input, EV_KEY, button->code, 1);
 436                 input_sync(input);
 437
 438                 if (!bdata->release_delay) {
 439                         input_event(input, EV_KEY, button->code, 0);
 440                         input_sync(input);
 441                         goto out;
 442                 }
 443
 444                 bdata->key_pressed = true;
 445         }
 446
 447         if (bdata->release_delay)
 448                 mod_timer(&bdata->release_timer,
 449                         jiffies + msecs_to_jiffies(bdata->release_delay));
 450 out:
 451         spin_unlock_irqrestore(&bdata->lock, flags);
 452         return IRQ_HANDLED;
 453 }
 454
 455 static void gpio_keys_quiesce_key(void *data)
 456 {
 457         struct gpio_button_data *bdata = data;
 458
 459         if (gpio_is_valid(bdata->button->gpio))
 460                 cancel_delayed_work_sync(&bdata->work);
 461         else
 462                 del_timer_sync(&bdata->release_timer);
 463 }
 464
 465 static int gpio_keys_setup_key(struct platform_device *pdev,
 466                                 struct input_dev *input,
 467                                 struct gpio_button_data *bdata,
 468                                 const struct gpio_keys_button *button)
 469 {
 470         const char *desc = button->desc ? button->desc : "gpio_keys";
 471         struct device *dev = &pdev->dev;
 472         irq_handler_t isr;
 473         unsigned long irqflags;
 474         int irq;
 475         int error;
 476
 477         bdata->input = input;
 478         bdata->button = button;
 479         spin_lock_init(&bdata->lock);
 480
 481         if (gpio_is_valid(button->gpio)) {
 482
 483                 error = devm_gpio_request_one(&pdev->dev, button->gpio,
 484                                               GPIOF_IN, desc);
 485                 if (error < 0) {
 486                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
 487                                 button->gpio, error);
 488                         return error;
 489                 }
 490
 491                 if (button->debounce_interval) {
 492                         error = gpio_set_debounce(button->gpio,
 493                                         button->debounce_interval * 1000);
 494                         /* use timer if gpiolib doesn't provide debounce */
 495                         if (error < 0)
 496                                 bdata->software_debounce =
 497                                                 button->debounce_interval;
 498                 }
 499
 500                 if (button->irq) {
 501                         bdata->irq = button->irq;
 502                 } else {
 503                         irq = gpio_to_irq(button->gpio);
 504                         if (irq < 0) {
 505                                 error = irq;
 506                                 dev_err(dev,
 507                                         "Unable to get irq number for GPIO %d, error %d\n",
 508                                         button->gpio, error);
 509                                 return error;
 510                         }
 511                         bdata->irq = irq;
 512                 }
 513
 514                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
 515
 516                 isr = gpio_keys_gpio_isr;
 517                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 518
 519         } else {
 520                 if (!button->irq) {
 521                         dev_err(dev, "No IRQ specified\n");
 522                         return -EINVAL;
 523                 }
 524                 bdata->irq = button->irq;
 525
 526                 if (button->type && button->type != EV_KEY) {
 527                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 528                         return -EINVAL;
 529                 }
 530
 531                 bdata->release_delay = button->debounce_interval;
 532                 setup_timer(&bdata->release_timer,
 533                             gpio_keys_irq_timer, (unsigned long)bdata);
 534
 535                 isr = gpio_keys_irq_isr;
 536                 irqflags = 0;
 537         }
 538
 539         input_set_capability(input, button->type ?: EV_KEY, button->code);
 540
 541         /*
 542          * Install custom action to cancel release timer and
 543          * workqueue item.
 544          */
 545         error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
 546         if (error) {
 547                 dev_err(&pdev->dev,
 548                         "failed to register quiesce action, error: %d\n",
 549                         error);
 550                 return error;
 551         }
 552
 553         /*
 554          * If platform has specified that the button can be disabled,
 555          * we don't want it to share the interrupt line.
 556          */
 557         if (!button->can_disable)
 558                 irqflags |= IRQF_SHARED;
 559
 560         error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
 561                                              isr, irqflags, desc, bdata);
 562         if (error < 0) {
 563                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 564                         bdata->irq, error);
 565                 return error;
 566         }
 567
 568         return 0;
 569 }
 570
 571 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 572 {
 573         struct input_dev *input = ddata->input;
 574         int i;
 575
 576         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 577                 struct gpio_button_data *bdata = &ddata->data[i];
 578                 if (gpio_is_valid(bdata->button->gpio))
 579                         gpio_keys_gpio_report_event(bdata);
 580         }
 581         input_sync(input);
 582 }
 583
 584 static int gpio_keys_open(struct input_dev *input)
 585 {
 586         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 587         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 588         int error;
 589
 590         if (pdata->enable) {
 591                 error = pdata->enable(input->dev.parent);
 592                 if (error)
 593                         return error;
 594         }
 595
 596         /* Report current state of buttons that are connected to GPIOs */
 597         gpio_keys_report_state(ddata);
 598
 599         return 0;
 600 }
 601
 602 static void gpio_keys_close(struct input_dev *input)
 603 {
 604         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 605         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 606
 607         if (pdata->disable)
 608                 pdata->disable(input->dev.parent);
 609 }
 610
 611 /*
 612  * Handlers for alternative sources of platform_data
 613  */
 614
 615 #ifdef CONFIG_OF
 616 /*
 617  * Translate OpenFirmware node properties into platform_data
 618  */
 619 static struct gpio_keys_platform_data *
 620 gpio_keys_get_devtree_pdata(struct device *dev)
 621 {
 622         struct device_node *node, *pp;
 623         struct gpio_keys_platform_data *pdata;
 624         struct gpio_keys_button *button;
 625         int error;
 626         int nbuttons;
 627         int i;
 628
 629         node = dev->of_node;
 630         if (!node)
 631                 return ERR_PTR(-ENODEV);
 632
 633         nbuttons = of_get_available_child_count(node);
 634         if (nbuttons == 0)
 635                 return ERR_PTR(-ENODEV);
 636
 637         pdata = devm_kzalloc(dev,
 638                              sizeof(*pdata) + nbuttons * sizeof(*button),
 639                              GFP_KERNEL);
 640         if (!pdata)
 641                 return ERR_PTR(-ENOMEM);
 642
 643         pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
 644         pdata->nbuttons = nbuttons;
 645
 646         pdata->rep = !!of_get_property(node, "autorepeat", NULL);
 647
 648         of_property_read_string(node, "label", &pdata->name);
 649
 650         i = 0;
 651         for_each_available_child_of_node(node, pp) {
 652                 enum of_gpio_flags flags;
 653
 654                 button = &pdata->buttons[i++];
 655
 656                 button->gpio = of_get_gpio_flags(pp, 0, &flags);
 657                 if (button->gpio < 0) {
 658                         error = button->gpio;
 659                         if (error != -ENOENT) {
 660                                 if (error != -EPROBE_DEFER)
 661                                         dev_err(dev,
 662                                                 "Failed to get gpio flags, error: %d\n",
 663                                                 error);
 664                                 return ERR_PTR(error);
 665                         }
 666                 } else {
 667                         button->active_low = flags & OF_GPIO_ACTIVE_LOW;
 668                 }
 669
 670                 button->irq = irq_of_parse_and_map(pp, 0);
 671
 672                 if (!gpio_is_valid(button->gpio) && !button->irq) {
 673                         dev_err(dev, "Found button without gpios or irqs\n");
 674                         return ERR_PTR(-EINVAL);
 675                 }
 676
 677                 if (of_property_read_u32(pp, "linux,code", &button->code)) {
 678                         dev_err(dev, "Button without keycode: 0x%x\n",
 679                                 button->gpio);
 680                         return ERR_PTR(-EINVAL);
 681                 }
 682
 683                 button->desc = of_get_property(pp, "label", NULL);
 684
 685                 if (of_property_read_u32(pp, "linux,input-type", &button->type))
 686                         button->type = EV_KEY;
 687
 688                 button->wakeup = of_property_read_bool(pp, "wakeup-source") ||
 689                                  /* legacy name */
 690                                  of_property_read_bool(pp, "gpio-key,wakeup");
 691
 692                 button->can_disable = !!of_get_property(pp, "linux,can-disable", NULL);
 693
 694                 if (of_property_read_u32(pp, "debounce-interval",
 695                                          &button->debounce_interval))
 696                         button->debounce_interval = 5;
 697         }
 698
 699         if (pdata->nbuttons == 0)
 700                 return ERR_PTR(-EINVAL);
 701
 702         return pdata;
 703 }
 704
 705 static const struct of_device_id gpio_keys_of_match[] = {
 706         { .compatible = "gpio-keys", },
 707         { },
 708 };
 709 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 710
 711 #else
 712
 713 static inline struct gpio_keys_platform_data *
 714 gpio_keys_get_devtree_pdata(struct device *dev)
 715 {
 716         return ERR_PTR(-ENODEV);
 717 }
 718
 719 #endif
 720
 721 static int gpio_keys_probe(struct platform_device *pdev)
 722 {
 723         struct device *dev = &pdev->dev;
 724         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 725         struct gpio_keys_drvdata *ddata;
 726         struct input_dev *input;
 727         size_t size;
 728         int i, error;
 729         int wakeup = 0;
 730
 731         if (!pdata) {
 732                 pdata = gpio_keys_get_devtree_pdata(dev);
 733                 if (IS_ERR(pdata))
 734                         return PTR_ERR(pdata);
 735         }
 736
 737         size = sizeof(struct gpio_keys_drvdata) +
 738                         pdata->nbuttons * sizeof(struct gpio_button_data);
 739         ddata = devm_kzalloc(dev, size, GFP_KERNEL);
 740         if (!ddata) {
 741                 dev_err(dev, "failed to allocate state\n");
 742                 return -ENOMEM;
 743         }
 744
 745         input = devm_input_allocate_device(dev);
 746         if (!input) {
 747                 dev_err(dev, "failed to allocate input device\n");
 748                 return -ENOMEM;
 749         }
 750
 751         ddata->pdata = pdata;
 752         ddata->input = input;
 753         mutex_init(&ddata->disable_lock);
 754
 755         platform_set_drvdata(pdev, ddata);
 756         input_set_drvdata(input, ddata);
 757
 758         input->name = pdata->name ? : pdev->name;
 759         input->phys = "gpio-keys/input0";
 760         input->dev.parent = &pdev->dev;
 761         input->open = gpio_keys_open;
 762         input->close = gpio_keys_close;
 763
 764         input->id.bustype = BUS_HOST;
 765         input->id.vendor = 0x0001;
 766         input->id.product = 0x0001;
 767         input->id.version = 0x0100;
 768
 769         /* Enable auto repeat feature of Linux input subsystem */
 770         if (pdata->rep)
 771                 __set_bit(EV_REP, input->evbit);
 772
 773         for (i = 0; i < pdata->nbuttons; i++) {
 774                 const struct gpio_keys_button *button = &pdata->buttons[i];
 775                 struct gpio_button_data *bdata = &ddata->data[i];
 776
 777                 error = gpio_keys_setup_key(pdev, input, bdata, button);
 778                 if (error)
 779                         return error;
 780
 781                 if (button->wakeup)
 782                         wakeup = 1;
 783         }
 784
 785         error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 786         if (error) {
 787                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
 788                         error);
 789                 return error;
 790         }
 791
 792         error = input_register_device(input);
 793         if (error) {
 794                 dev_err(dev, "Unable to register input device, error: %d\n",
 795                         error);
 796                 goto err_remove_group;
 797         }
 798
 799         device_init_wakeup(&pdev->dev, wakeup);
 800
 801         return 0;
 802
 803 err_remove_group:
 804         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 805         return error;
 806 }
 807
 808 static int gpio_keys_remove(struct platform_device *pdev)
 809 {
 810         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 811
 812         device_init_wakeup(&pdev->dev, 0);
 813
 814         return 0;
 815 }
 816
 817 #ifdef CONFIG_PM_SLEEP
 818 static int gpio_keys_suspend(struct device *dev)
 819 {
 820         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 821         struct input_dev *input = ddata->input;
 822         int i;
 823
 824         if (device_may_wakeup(dev)) {
 825                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
 826                         struct gpio_button_data *bdata = &ddata->data[i];
 827                         if (bdata->button->wakeup)
 828                                 enable_irq_wake(bdata->irq);
 829                 }
 830         } else {
 831                 mutex_lock(&input->mutex);
 832                 if (input->users)
 833                         gpio_keys_close(input);
 834                 mutex_unlock(&input->mutex);
 835         }
 836
 837         return 0;
 838 }
 839
 840 static int gpio_keys_resume(struct device *dev)
 841 {
 842         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 843         struct input_dev *input = ddata->input;
 844         int error = 0;
 845         int i;
 846
 847         if (device_may_wakeup(dev)) {
 848                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
 849                         struct gpio_button_data *bdata = &ddata->data[i];
 850                         if (bdata->button->wakeup)
 851                                 disable_irq_wake(bdata->irq);
 852                 }
 853         } else {
 854                 mutex_lock(&input->mutex);
 855                 if (input->users)
 856                         error = gpio_keys_open(input);
 857                 mutex_unlock(&input->mutex);
 858         }
 859
 860         if (error)
 861                 return error;
 862
 863         gpio_keys_report_state(ddata);
 864         return 0;
 865 }
 866 #endif
 867
 868 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
 869
 870 static struct platform_driver gpio_keys_device_driver = {
 871         .probe          = gpio_keys_probe,
 872         .remove         = gpio_keys_remove,
 873         .driver         = {
 874                 .name   = "gpio-keys",
 875                 .pm     = &gpio_keys_pm_ops,
 876                 .of_match_table = of_match_ptr(gpio_keys_of_match),
 877         }
 878 };
 879
 880 static int __init gpio_keys_init(void)
 881 {
 882         return platform_driver_register(&gpio_keys_device_driver);
 883 }
 884
 885 static void __exit gpio_keys_exit(void)
 886 {
 887         platform_driver_unregister(&gpio_keys_device_driver);
 888 }
 889
 890 late_initcall(gpio_keys_init);
 891 module_exit(gpio_keys_exit);
 892
 893 MODULE_LICENSE("GPL");
 894 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 895 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
 896 MODULE_ALIAS("platform:gpio-keys");