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_platform.h>
  30 #include <linux/of_gpio.h>
  31 #include <linux/spinlock.h>
  32
  33 struct gpio_button_data {
  34         const struct gpio_keys_button *button;
  35         struct input_dev *input;
  36         struct timer_list timer;
  37         struct work_struct work;
  38         unsigned int timer_debounce;    /* in msecs */
  39         unsigned int irq;
  40         spinlock_t lock;
  41         bool disabled;
  42         bool key_pressed;
  43 };
  44
  45 struct gpio_keys_drvdata {
  46         const struct gpio_keys_platform_data *pdata;
  47         struct input_dev *input;
  48         struct mutex disable_lock;
  49         struct gpio_button_data data[0];
  50 };
  51
  52 /*
  53  * SYSFS interface for enabling/disabling keys and switches:
  54  *
  55  * There are 4 attributes under /sys/devices/platform/gpio-keys/
  56  *      keys [ro]              - bitmap of keys (EV_KEY) which can be
  57  *                               disabled
  58  *      switches [ro]          - bitmap of switches (EV_SW) which can be
  59  *                               disabled
  60  *      disabled_keys [rw]     - bitmap of keys currently disabled
  61  *      disabled_switches [rw] - bitmap of switches currently disabled
  62  *
  63  * Userland can change these values and hence disable event generation
  64  * for each key (or switch). Disabling a key means its interrupt line
  65  * is disabled.
  66  *
  67  * For example, if we have following switches set up as gpio-keys:
  68  *      SW_DOCK = 5
  69  *      SW_CAMERA_LENS_COVER = 9
  70  *      SW_KEYPAD_SLIDE = 10
  71  *      SW_FRONT_PROXIMITY = 11
  72  * This is read from switches:
  73  *      11-9,5
  74  * Next we want to disable proximity (11) and dock (5), we write:
  75  *      11,5
  76  * to file disabled_switches. Now proximity and dock IRQs are disabled.
  77  * This can be verified by reading the file disabled_switches:
  78  *      11,5
  79  * If we now want to enable proximity (11) switch we write:
  80  *      5
  81  * to disabled_switches.
  82  *
  83  * We can disable only those keys which don't allow sharing the irq.
  84  */
  85
  86 /**
  87  * get_n_events_by_type() - returns maximum number of events per @type
  88  * @type: type of button (%EV_KEY, %EV_SW)
  89  *
  90  * Return value of this function can be used to allocate bitmap
  91  * large enough to hold all bits for given type.
  92  */
  93 static inline int get_n_events_by_type(int type)
  94 {
  95         BUG_ON(type != EV_SW && type != EV_KEY);
  96
  97         return (type == EV_KEY) ? KEY_CNT : SW_CNT;
  98 }
  99
 100 /**
 101  * gpio_keys_disable_button() - disables given GPIO button
 102  * @bdata: button data for button to be disabled
 103  *
 104  * Disables button pointed by @bdata. This is done by masking
 105  * IRQ line. After this function is called, button won't generate
 106  * input events anymore. Note that one can only disable buttons
 107  * that don't share IRQs.
 108  *
 109  * Make sure that @bdata->disable_lock is locked when entering
 110  * this function to avoid races when concurrent threads are
 111  * disabling buttons at the same time.
 112  */
 113 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
 114 {
 115         if (!bdata->disabled) {
 116                 /*
 117                  * Disable IRQ and possible debouncing timer.
 118                  */
 119                 disable_irq(bdata->irq);
 120                 if (bdata->timer_debounce)
 121                         del_timer_sync(&bdata->timer);
 122
 123                 bdata->disabled = true;
 124         }
 125 }
 126
 127 /**
 128  * gpio_keys_enable_button() - enables given GPIO button
 129  * @bdata: button data for button to be disabled
 130  *
 131  * Enables given button pointed by @bdata.
 132  *
 133  * Make sure that @bdata->disable_lock is locked when entering
 134  * this function to avoid races with concurrent threads trying
 135  * to enable the same button at the same time.
 136  */
 137 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
 138 {
 139         if (bdata->disabled) {
 140                 enable_irq(bdata->irq);
 141                 bdata->disabled = false;
 142         }
 143 }
 144
 145 /**
 146  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
 147  * @ddata: pointer to drvdata
 148  * @buf: buffer where stringified bitmap is written
 149  * @type: button type (%EV_KEY, %EV_SW)
 150  * @only_disabled: does caller want only those buttons that are
 151  *                 currently disabled or all buttons that can be
 152  *                 disabled
 153  *
 154  * This function writes buttons that can be disabled to @buf. If
 155  * @only_disabled is true, then @buf contains only those buttons
 156  * that are currently disabled. Returns 0 on success or negative
 157  * errno on failure.
 158  */
 159 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
 160                                           char *buf, unsigned int type,
 161                                           bool only_disabled)
 162 {
 163         int n_events = get_n_events_by_type(type);
 164         unsigned long *bits;
 165         ssize_t ret;
 166         int i;
 167
 168         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
 169         if (!bits)
 170                 return -ENOMEM;
 171
 172         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 173                 struct gpio_button_data *bdata = &ddata->data[i];
 174
 175                 if (bdata->button->type != type)
 176                         continue;
 177
 178                 if (only_disabled && !bdata->disabled)
 179                         continue;
 180
 181                 __set_bit(bdata->button->code, bits);
 182         }
 183
 184         ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
 185         buf[ret++] = '\n';
 186         buf[ret] = '\0';
 187
 188         kfree(bits);
 189
 190         return ret;
 191 }
 192
 193 /**
 194  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
 195  * @ddata: pointer to drvdata
 196  * @buf: buffer from userspace that contains stringified bitmap
 197  * @type: button type (%EV_KEY, %EV_SW)
 198  *
 199  * This function parses stringified bitmap from @buf and disables/enables
 200  * GPIO buttons accordingly. Returns 0 on success and negative error
 201  * on failure.
 202  */
 203 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 204                                            const char *buf, unsigned int type)
 205 {
 206         int n_events = get_n_events_by_type(type);
 207         unsigned long *bits;
 208         ssize_t error;
 209         int i;
 210
 211         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
 212         if (!bits)
 213                 return -ENOMEM;
 214
 215         error = bitmap_parselist(buf, bits, n_events);
 216         if (error)
 217                 goto out;
 218
 219         /* First validate */
 220         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 221                 struct gpio_button_data *bdata = &ddata->data[i];
 222
 223                 if (bdata->button->type != type)
 224                         continue;
 225
 226                 if (test_bit(bdata->button->code, bits) &&
 227                     !bdata->button->can_disable) {
 228                         error = -EINVAL;
 229                         goto out;
 230                 }
 231         }
 232
 233         mutex_lock(&ddata->disable_lock);
 234
 235         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 236                 struct gpio_button_data *bdata = &ddata->data[i];
 237
 238                 if (bdata->button->type != type)
 239                         continue;
 240
 241                 if (test_bit(bdata->button->code, bits))
 242                         gpio_keys_disable_button(bdata);
 243                 else
 244                         gpio_keys_enable_button(bdata);
 245         }
 246
 247         mutex_unlock(&ddata->disable_lock);
 248
 249 out:
 250         kfree(bits);
 251         return error;
 252 }
 253
 254 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
 255 static ssize_t gpio_keys_show_##name(struct device *dev,                \
 256                                      struct device_attribute *attr,     \
 257                                      char *buf)                         \
 258 {                                                                       \
 259         struct platform_device *pdev = to_platform_device(dev);         \
 260         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 261                                                                         \
 262         return gpio_keys_attr_show_helper(ddata, buf,                   \
 263                                           type, only_disabled);         \
 264 }
 265
 266 ATTR_SHOW_FN(keys, EV_KEY, false);
 267 ATTR_SHOW_FN(switches, EV_SW, false);
 268 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
 269 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
 270
 271 /*
 272  * ATTRIBUTES:
 273  *
 274  * /sys/devices/platform/gpio-keys/keys [ro]
 275  * /sys/devices/platform/gpio-keys/switches [ro]
 276  */
 277 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
 278 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
 279
 280 #define ATTR_STORE_FN(name, type)                                       \
 281 static ssize_t gpio_keys_store_##name(struct device *dev,               \
 282                                       struct device_attribute *attr,    \
 283                                       const char *buf,                  \
 284                                       size_t count)                     \
 285 {                                                                       \
 286         struct platform_device *pdev = to_platform_device(dev);         \
 287         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 288         ssize_t error;                                                  \
 289                                                                         \
 290         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
 291         if (error)                                                      \
 292                 return error;                                           \
 293                                                                         \
 294         return count;                                                   \
 295 }
 296
 297 ATTR_STORE_FN(disabled_keys, EV_KEY);
 298 ATTR_STORE_FN(disabled_switches, EV_SW);
 299
 300 /*
 301  * ATTRIBUTES:
 302  *
 303  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
 304  * /sys/devices/platform/gpio-keys/disables_switches [rw]
 305  */
 306 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
 307                    gpio_keys_show_disabled_keys,
 308                    gpio_keys_store_disabled_keys);
 309 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
 310                    gpio_keys_show_disabled_switches,
 311                    gpio_keys_store_disabled_switches);
 312
 313 static struct attribute *gpio_keys_attrs[] = {
 314         &dev_attr_keys.attr,
 315         &dev_attr_switches.attr,
 316         &dev_attr_disabled_keys.attr,
 317         &dev_attr_disabled_switches.attr,
 318         NULL,
 319 };
 320
 321 static struct attribute_group gpio_keys_attr_group = {
 322         .attrs = gpio_keys_attrs,
 323 };
 324
 325 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
 326 {
 327         const struct gpio_keys_button *button = bdata->button;
 328         struct input_dev *input = bdata->input;
 329         unsigned int type = button->type ?: EV_KEY;
 330         int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
 331
 332         if (type == EV_ABS) {
 333                 if (state)
 334                         input_event(input, type, button->code, button->value);
 335         } else {
 336                 input_event(input, type, button->code, !!state);
 337         }
 338         input_sync(input);
 339 }
 340
 341 static void gpio_keys_gpio_work_func(struct work_struct *work)
 342 {
 343         struct gpio_button_data *bdata =
 344                 container_of(work, struct gpio_button_data, work);
 345
 346         gpio_keys_gpio_report_event(bdata);
 347
 348         if (bdata->button->wakeup)
 349                 pm_relax(bdata->input->dev.parent);
 350 }
 351
 352 static void gpio_keys_gpio_timer(unsigned long _data)
 353 {
 354         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
 355
 356         schedule_work(&bdata->work);
 357 }
 358
 359 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
 360 {
 361         struct gpio_button_data *bdata = dev_id;
 362
 363         BUG_ON(irq != bdata->irq);
 364
 365         if (bdata->button->wakeup)
 366                 pm_stay_awake(bdata->input->dev.parent);
 367         if (bdata->timer_debounce)
 368                 mod_timer(&bdata->timer,
 369                         jiffies + msecs_to_jiffies(bdata->timer_debounce));
 370         else
 371                 schedule_work(&bdata->work);
 372
 373         return IRQ_HANDLED;
 374 }
 375
 376 static void gpio_keys_irq_timer(unsigned long _data)
 377 {
 378         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
 379         struct input_dev *input = bdata->input;
 380         unsigned long flags;
 381
 382         spin_lock_irqsave(&bdata->lock, flags);
 383         if (bdata->key_pressed) {
 384                 input_event(input, EV_KEY, bdata->button->code, 0);
 385                 input_sync(input);
 386                 bdata->key_pressed = false;
 387         }
 388         spin_unlock_irqrestore(&bdata->lock, flags);
 389 }
 390
 391 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
 392 {
 393         struct gpio_button_data *bdata = dev_id;
 394         const struct gpio_keys_button *button = bdata->button;
 395         struct input_dev *input = bdata->input;
 396         unsigned long flags;
 397
 398         BUG_ON(irq != bdata->irq);
 399
 400         spin_lock_irqsave(&bdata->lock, flags);
 401
 402         if (!bdata->key_pressed) {
 403                 if (bdata->button->wakeup)
 404                         pm_wakeup_event(bdata->input->dev.parent, 0);
 405
 406                 input_event(input, EV_KEY, button->code, 1);
 407                 input_sync(input);
 408
 409                 if (!bdata->timer_debounce) {
 410                         input_event(input, EV_KEY, button->code, 0);
 411                         input_sync(input);
 412                         goto out;
 413                 }
 414
 415                 bdata->key_pressed = true;
 416         }
 417
 418         if (bdata->timer_debounce)
 419                 mod_timer(&bdata->timer,
 420                         jiffies + msecs_to_jiffies(bdata->timer_debounce));
 421 out:
 422         spin_unlock_irqrestore(&bdata->lock, flags);
 423         return IRQ_HANDLED;
 424 }
 425
 426 static int gpio_keys_setup_key(struct platform_device *pdev,
 427                                 struct input_dev *input,
 428                                 struct gpio_button_data *bdata,
 429                                 const struct gpio_keys_button *button)
 430 {
 431         const char *desc = button->desc ? button->desc : "gpio_keys";
 432         struct device *dev = &pdev->dev;
 433         irq_handler_t isr;
 434         unsigned long irqflags;
 435         int irq, error;
 436
 437         bdata->input = input;
 438         bdata->button = button;
 439         spin_lock_init(&bdata->lock);
 440
 441         if (gpio_is_valid(button->gpio)) {
 442
 443                 error = gpio_request_one(button->gpio, GPIOF_IN, desc);
 444                 if (error < 0) {
 445                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
 446                                 button->gpio, error);
 447                         return error;
 448                 }
 449
 450                 if (button->debounce_interval) {
 451                         error = gpio_set_debounce(button->gpio,
 452                                         button->debounce_interval * 1000);
 453                         /* use timer if gpiolib doesn't provide debounce */
 454                         if (error < 0)
 455                                 bdata->timer_debounce =
 456                                                 button->debounce_interval;
 457                 }
 458
 459                 irq = gpio_to_irq(button->gpio);
 460                 if (irq < 0) {
 461                         error = irq;
 462                         dev_err(dev,
 463                                 "Unable to get irq number for GPIO %d, error %d\n",
 464                                 button->gpio, error);
 465                         goto fail;
 466                 }
 467                 bdata->irq = irq;
 468
 469                 INIT_WORK(&bdata->work, gpio_keys_gpio_work_func);
 470                 setup_timer(&bdata->timer,
 471                             gpio_keys_gpio_timer, (unsigned long)bdata);
 472
 473                 isr = gpio_keys_gpio_isr;
 474                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 475
 476         } else {
 477                 if (!button->irq) {
 478                         dev_err(dev, "No IRQ specified\n");
 479                         return -EINVAL;
 480                 }
 481                 bdata->irq = button->irq;
 482
 483                 if (button->type && button->type != EV_KEY) {
 484                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 485                         return -EINVAL;
 486                 }
 487
 488                 bdata->timer_debounce = button->debounce_interval;
 489                 setup_timer(&bdata->timer,
 490                             gpio_keys_irq_timer, (unsigned long)bdata);
 491
 492                 isr = gpio_keys_irq_isr;
 493                 irqflags = 0;
 494         }
 495
 496         input_set_capability(input, button->type ?: EV_KEY, button->code);
 497
 498         /*
 499          * If platform has specified that the button can be disabled,
 500          * we don't want it to share the interrupt line.
 501          */
 502         if (!button->can_disable)
 503                 irqflags |= IRQF_SHARED;
 504
 505         error = request_any_context_irq(bdata->irq, isr, irqflags, desc, bdata);
 506         if (error < 0) {
 507                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 508                         bdata->irq, error);
 509                 goto fail;
 510         }
 511
 512         return 0;
 513
 514 fail:
 515         if (gpio_is_valid(button->gpio))
 516                 gpio_free(button->gpio);
 517
 518         return error;
 519 }
 520
 521 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 522 {
 523         struct input_dev *input = ddata->input;
 524         int i;
 525
 526         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 527                 struct gpio_button_data *bdata = &ddata->data[i];
 528                 if (gpio_is_valid(bdata->button->gpio))
 529                         gpio_keys_gpio_report_event(bdata);
 530         }
 531         input_sync(input);
 532 }
 533
 534 static int gpio_keys_open(struct input_dev *input)
 535 {
 536         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 537         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 538         int error;
 539
 540         if (pdata->enable) {
 541                 error = pdata->enable(input->dev.parent);
 542                 if (error)
 543                         return error;
 544         }
 545
 546         /* Report current state of buttons that are connected to GPIOs */
 547         gpio_keys_report_state(ddata);
 548
 549         return 0;
 550 }
 551
 552 static void gpio_keys_close(struct input_dev *input)
 553 {
 554         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 555         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 556
 557         if (pdata->disable)
 558                 pdata->disable(input->dev.parent);
 559 }
 560
 561 /*
 562  * Handlers for alternative sources of platform_data
 563  */
 564
 565 #ifdef CONFIG_OF
 566 /*
 567  * Translate OpenFirmware node properties into platform_data
 568  */
 569 static struct gpio_keys_platform_data *
 570 gpio_keys_get_devtree_pdata(struct device *dev)
 571 {
 572         struct device_node *node, *pp;
 573         struct gpio_keys_platform_data *pdata;
 574         struct gpio_keys_button *button;
 575         int error;
 576         int nbuttons;
 577         int i;
 578
 579         node = dev->of_node;
 580         if (!node) {
 581                 error = -ENODEV;
 582                 goto err_out;
 583         }
 584
 585         nbuttons = of_get_child_count(node);
 586         if (nbuttons == 0) {
 587                 error = -ENODEV;
 588                 goto err_out;
 589         }
 590
 591         pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
 592                         GFP_KERNEL);
 593         if (!pdata) {
 594                 error = -ENOMEM;
 595                 goto err_out;
 596         }
 597
 598         pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
 599         pdata->nbuttons = nbuttons;
 600
 601         pdata->rep = !!of_get_property(node, "autorepeat", NULL);
 602
 603         i = 0;
 604         for_each_child_of_node(node, pp) {
 605                 int gpio;
 606                 enum of_gpio_flags flags;
 607
 608                 if (!of_find_property(pp, "gpios", NULL)) {
 609                         pdata->nbuttons--;
 610                         dev_warn(dev, "Found button without gpios\n");
 611                         continue;
 612                 }
 613
 614                 gpio = of_get_gpio_flags(pp, 0, &flags);
 615                 if (gpio < 0) {
 616                         error = gpio;
 617                         if (error != -EPROBE_DEFER)
 618                                 dev_err(dev,
 619                                         "Failed to get gpio flags, error: %d\n",
 620                                         error);
 621                         goto err_free_pdata;
 622                 }
 623
 624                 button = &pdata->buttons[i++];
 625
 626                 button->gpio = gpio;
 627                 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
 628
 629                 if (of_property_read_u32(pp, "linux,code", &button->code)) {
 630                         dev_err(dev, "Button without keycode: 0x%x\n",
 631                                 button->gpio);
 632                         error = -EINVAL;
 633                         goto err_free_pdata;
 634                 }
 635
 636                 button->desc = of_get_property(pp, "label", NULL);
 637
 638                 if (of_property_read_u32(pp, "linux,input-type", &button->type))
 639                         button->type = EV_KEY;
 640
 641                 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
 642
 643                 if (of_property_read_u32(pp, "debounce-interval",
 644                                          &button->debounce_interval))
 645                         button->debounce_interval = 5;
 646         }
 647
 648         if (pdata->nbuttons == 0) {
 649                 error = -EINVAL;
 650                 goto err_free_pdata;
 651         }
 652
 653         return pdata;
 654
 655 err_free_pdata:
 656         kfree(pdata);
 657 err_out:
 658         return ERR_PTR(error);
 659 }
 660
 661 static struct of_device_id gpio_keys_of_match[] = {
 662         { .compatible = "gpio-keys", },
 663         { },
 664 };
 665 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 666
 667 #else
 668
 669 static inline struct gpio_keys_platform_data *
 670 gpio_keys_get_devtree_pdata(struct device *dev)
 671 {
 672         return ERR_PTR(-ENODEV);
 673 }
 674
 675 #endif
 676
 677 static void gpio_remove_key(struct gpio_button_data *bdata)
 678 {
 679         free_irq(bdata->irq, bdata);
 680         if (bdata->timer_debounce)
 681                 del_timer_sync(&bdata->timer);
 682         cancel_work_sync(&bdata->work);
 683         if (gpio_is_valid(bdata->button->gpio))
 684                 gpio_free(bdata->button->gpio);
 685 }
 686
 687 static int gpio_keys_probe(struct platform_device *pdev)
 688 {
 689         struct device *dev = &pdev->dev;
 690         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 691         struct gpio_keys_drvdata *ddata;
 692         struct input_dev *input;
 693         int i, error;
 694         int wakeup = 0;
 695
 696         if (!pdata) {
 697                 pdata = gpio_keys_get_devtree_pdata(dev);
 698                 if (IS_ERR(pdata))
 699                         return PTR_ERR(pdata);
 700         }
 701
 702         ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
 703                         pdata->nbuttons * sizeof(struct gpio_button_data),
 704                         GFP_KERNEL);
 705         input = input_allocate_device();
 706         if (!ddata || !input) {
 707                 dev_err(dev, "failed to allocate state\n");
 708                 error = -ENOMEM;
 709                 goto fail1;
 710         }
 711
 712         ddata->pdata = pdata;
 713         ddata->input = input;
 714         mutex_init(&ddata->disable_lock);
 715
 716         platform_set_drvdata(pdev, ddata);
 717         input_set_drvdata(input, ddata);
 718
 719         input->name = pdata->name ? : pdev->name;
 720         input->phys = "gpio-keys/input0";
 721         input->dev.parent = &pdev->dev;
 722         input->open = gpio_keys_open;
 723         input->close = gpio_keys_close;
 724
 725         input->id.bustype = BUS_HOST;
 726         input->id.vendor = 0x0001;
 727         input->id.product = 0x0001;
 728         input->id.version = 0x0100;
 729
 730         /* Enable auto repeat feature of Linux input subsystem */
 731         if (pdata->rep)
 732                 __set_bit(EV_REP, input->evbit);
 733
 734         for (i = 0; i < pdata->nbuttons; i++) {
 735                 const struct gpio_keys_button *button = &pdata->buttons[i];
 736                 struct gpio_button_data *bdata = &ddata->data[i];
 737
 738                 error = gpio_keys_setup_key(pdev, input, bdata, button);
 739                 if (error)
 740                         goto fail2;
 741
 742                 if (button->wakeup)
 743                         wakeup = 1;
 744         }
 745
 746         error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 747         if (error) {
 748                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
 749                         error);
 750                 goto fail2;
 751         }
 752
 753         error = input_register_device(input);
 754         if (error) {
 755                 dev_err(dev, "Unable to register input device, error: %d\n",
 756                         error);
 757                 goto fail3;
 758         }
 759
 760         device_init_wakeup(&pdev->dev, wakeup);
 761
 762         return 0;
 763
 764  fail3:
 765         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 766  fail2:
 767         while (--i >= 0)
 768                 gpio_remove_key(&ddata->data[i]);
 769
 770         platform_set_drvdata(pdev, NULL);
 771  fail1:
 772         input_free_device(input);
 773         kfree(ddata);
 774         /* If we have no platform data, we allocated pdata dynamically. */
 775         if (!dev_get_platdata(&pdev->dev))
 776                 kfree(pdata);
 777
 778         return error;
 779 }
 780
 781 static int gpio_keys_remove(struct platform_device *pdev)
 782 {
 783         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
 784         struct input_dev *input = ddata->input;
 785         int i;
 786
 787         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 788
 789         device_init_wakeup(&pdev->dev, 0);
 790
 791         for (i = 0; i < ddata->pdata->nbuttons; i++)
 792                 gpio_remove_key(&ddata->data[i]);
 793
 794         input_unregister_device(input);
 795
 796         /* If we have no platform data, we allocated pdata dynamically. */
 797         if (!dev_get_platdata(&pdev->dev))
 798                 kfree(ddata->pdata);
 799
 800         kfree(ddata);
 801
 802         return 0;
 803 }
 804
 805 #ifdef CONFIG_PM_SLEEP
 806 static int gpio_keys_suspend(struct device *dev)
 807 {
 808         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 809         struct input_dev *input = ddata->input;
 810         int i;
 811
 812         if (device_may_wakeup(dev)) {
 813                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
 814                         struct gpio_button_data *bdata = &ddata->data[i];
 815                         if (bdata->button->wakeup)
 816                                 enable_irq_wake(bdata->irq);
 817                 }
 818         } else {
 819                 mutex_lock(&input->mutex);
 820                 if (input->users)
 821                         gpio_keys_close(input);
 822                 mutex_unlock(&input->mutex);
 823         }
 824
 825         return 0;
 826 }
 827
 828 static int gpio_keys_resume(struct device *dev)
 829 {
 830         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 831         struct input_dev *input = ddata->input;
 832         int error = 0;
 833         int i;
 834
 835         if (device_may_wakeup(dev)) {
 836                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
 837                         struct gpio_button_data *bdata = &ddata->data[i];
 838                         if (bdata->button->wakeup)
 839                                 disable_irq_wake(bdata->irq);
 840                 }
 841         } else {
 842                 mutex_lock(&input->mutex);
 843                 if (input->users)
 844                         error = gpio_keys_open(input);
 845                 mutex_unlock(&input->mutex);
 846         }
 847
 848         if (error)
 849                 return error;
 850
 851         gpio_keys_report_state(ddata);
 852         return 0;
 853 }
 854 #endif
 855
 856 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
 857
 858 static struct platform_driver gpio_keys_device_driver = {
 859         .probe          = gpio_keys_probe,
 860         .remove         = gpio_keys_remove,
 861         .driver         = {
 862                 .name   = "gpio-keys",
 863                 .owner  = THIS_MODULE,
 864                 .pm     = &gpio_keys_pm_ops,
 865                 .of_match_table = of_match_ptr(gpio_keys_of_match),
 866         }
 867 };
 868
 869 static int __init gpio_keys_init(void)
 870 {
 871         return platform_driver_register(&gpio_keys_device_driver);
 872 }
 873
 874 static void __exit gpio_keys_exit(void)
 875 {
 876         platform_driver_unregister(&gpio_keys_device_driver);
 877 }
 878
 879 late_initcall(gpio_keys_init);
 880 module_exit(gpio_keys_exit);
 881
 882 MODULE_LICENSE("GPL");
 883 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 884 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
 885 MODULE_ALIAS("platform:gpio-keys");