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