drivers/input/keyboard/gpio_keys.c

   1 /*
   2  * Driver for keys on GPIO lines capable of generating interrupts.
   3  *
   4  * Copyright 2005 Phil Blundell
   5  * Copyright 2010, 2011 David Jander <david@protonic.nl>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13
  14 #include <linux/init.h>
  15 #include <linux/fs.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/irq.h>
  18 #include <linux/sched.h>
  19 #include <linux/pm.h>
  20 #include <linux/slab.h>
  21 #include <linux/sysctl.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/delay.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/input.h>
  26 #include <linux/gpio_keys.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/gpio.h>
  29 #include <linux/gpio/consumer.h>
  30 #include <linux/of.h>
  31 #include <linux/of_irq.h>
  32 #include <linux/spinlock.h>
  33 #include <dt-bindings/input/gpio-keys.h>
  34
  35 struct gpio_button_data {
  36         const struct gpio_keys_button *button;
  37         struct input_dev *input;
  38         struct gpio_desc *gpiod;
  39
  40         unsigned short *code;
  41
  42         struct timer_list release_timer;
  43         unsigned int release_delay;     /* in msecs, for IRQ-only buttons */
  44
  45         struct delayed_work work;
  46         unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
  47
  48         unsigned int irq;
  49         unsigned int wakeup_trigger_type;
  50         spinlock_t lock;
  51         bool disabled;
  52         bool key_pressed;
  53         bool suspended;
  54 };
  55
  56 struct gpio_keys_drvdata {
  57         const struct gpio_keys_platform_data *pdata;
  58         struct input_dev *input;
  59         struct mutex disable_lock;
  60         unsigned short *keymap;
  61         struct gpio_button_data data[0];
  62 };
  63
  64 /*
  65  * SYSFS interface for enabling/disabling keys and switches:
  66  *
  67  * There are 4 attributes under /sys/devices/platform/gpio-keys/
  68  *      keys [ro]              - bitmap of keys (EV_KEY) which can be
  69  *                               disabled
  70  *      switches [ro]          - bitmap of switches (EV_SW) which can be
  71  *                               disabled
  72  *      disabled_keys [rw]     - bitmap of keys currently disabled
  73  *      disabled_switches [rw] - bitmap of switches currently disabled
  74  *
  75  * Userland can change these values and hence disable event generation
  76  * for each key (or switch). Disabling a key means its interrupt line
  77  * is disabled.
  78  *
  79  * For example, if we have following switches set up as gpio-keys:
  80  *      SW_DOCK = 5
  81  *      SW_CAMERA_LENS_COVER = 9
  82  *      SW_KEYPAD_SLIDE = 10
  83  *      SW_FRONT_PROXIMITY = 11
  84  * This is read from switches:
  85  *      11-9,5
  86  * Next we want to disable proximity (11) and dock (5), we write:
  87  *      11,5
  88  * to file disabled_switches. Now proximity and dock IRQs are disabled.
  89  * This can be verified by reading the file disabled_switches:
  90  *      11,5
  91  * If we now want to enable proximity (11) switch we write:
  92  *      5
  93  * to disabled_switches.
  94  *
  95  * We can disable only those keys which don't allow sharing the irq.
  96  */
  97
  98 /**
  99  * get_n_events_by_type() - returns maximum number of events per @type
 100  * @type: type of button (%EV_KEY, %EV_SW)
 101  *
 102  * Return value of this function can be used to allocate bitmap
 103  * large enough to hold all bits for given type.
 104  */
 105 static int get_n_events_by_type(int type)
 106 {
 107         BUG_ON(type != EV_SW && type != EV_KEY);
 108
 109         return (type == EV_KEY) ? KEY_CNT : SW_CNT;
 110 }
 111
 112 /**
 113  * get_bm_events_by_type() - returns bitmap of supported events per @type
 114  * @input: input device from which bitmap is retrieved
 115  * @type: type of button (%EV_KEY, %EV_SW)
 116  *
 117  * Return value of this function can be used to allocate bitmap
 118  * large enough to hold all bits for given type.
 119  */
 120 static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
 121                                                   int type)
 122 {
 123         BUG_ON(type != EV_SW && type != EV_KEY);
 124
 125         return (type == EV_KEY) ? dev->keybit : dev->swbit;
 126 }
 127
 128 /**
 129  * gpio_keys_disable_button() - disables given GPIO button
 130  * @bdata: button data for button to be disabled
 131  *
 132  * Disables button pointed by @bdata. This is done by masking
 133  * IRQ line. After this function is called, button won't generate
 134  * input events anymore. Note that one can only disable buttons
 135  * that don't share IRQs.
 136  *
 137  * Make sure that @bdata->disable_lock is locked when entering
 138  * this function to avoid races when concurrent threads are
 139  * disabling buttons at the same time.
 140  */
 141 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
 142 {
 143         if (!bdata->disabled) {
 144                 /*
 145                  * Disable IRQ and associated timer/work structure.
 146                  */
 147                 disable_irq(bdata->irq);
 148
 149                 if (bdata->gpiod)
 150                         cancel_delayed_work_sync(&bdata->work);
 151                 else
 152                         del_timer_sync(&bdata->release_timer);
 153
 154                 bdata->disabled = true;
 155         }
 156 }
 157
 158 /**
 159  * gpio_keys_enable_button() - enables given GPIO button
 160  * @bdata: button data for button to be disabled
 161  *
 162  * Enables given button pointed by @bdata.
 163  *
 164  * Make sure that @bdata->disable_lock is locked when entering
 165  * this function to avoid races with concurrent threads trying
 166  * to enable the same button at the same time.
 167  */
 168 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
 169 {
 170         if (bdata->disabled) {
 171                 enable_irq(bdata->irq);
 172                 bdata->disabled = false;
 173         }
 174 }
 175
 176 /**
 177  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
 178  * @ddata: pointer to drvdata
 179  * @buf: buffer where stringified bitmap is written
 180  * @type: button type (%EV_KEY, %EV_SW)
 181  * @only_disabled: does caller want only those buttons that are
 182  *                 currently disabled or all buttons that can be
 183  *                 disabled
 184  *
 185  * This function writes buttons that can be disabled to @buf. If
 186  * @only_disabled is true, then @buf contains only those buttons
 187  * that are currently disabled. Returns 0 on success or negative
 188  * errno on failure.
 189  */
 190 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
 191                                           char *buf, unsigned int type,
 192                                           bool only_disabled)
 193 {
 194         int n_events = get_n_events_by_type(type);
 195         unsigned long *bits;
 196         ssize_t ret;
 197         int i;
 198
 199         bits = bitmap_zalloc(n_events, GFP_KERNEL);
 200         if (!bits)
 201                 return -ENOMEM;
 202
 203         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 204                 struct gpio_button_data *bdata = &ddata->data[i];
 205
 206                 if (bdata->button->type != type)
 207                         continue;
 208
 209                 if (only_disabled && !bdata->disabled)
 210                         continue;
 211
 212                 __set_bit(*bdata->code, bits);
 213         }
 214
 215         ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
 216         buf[ret++] = '\n';
 217         buf[ret] = '\0';
 218
 219         bitmap_free(bits);
 220
 221         return ret;
 222 }
 223
 224 /**
 225  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
 226  * @ddata: pointer to drvdata
 227  * @buf: buffer from userspace that contains stringified bitmap
 228  * @type: button type (%EV_KEY, %EV_SW)
 229  *
 230  * This function parses stringified bitmap from @buf and disables/enables
 231  * GPIO buttons accordingly. Returns 0 on success and negative error
 232  * on failure.
 233  */
 234 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 235                                            const char *buf, unsigned int type)
 236 {
 237         int n_events = get_n_events_by_type(type);
 238         const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
 239         unsigned long *bits;
 240         ssize_t error;
 241         int i;
 242
 243         bits = bitmap_zalloc(n_events, GFP_KERNEL);
 244         if (!bits)
 245                 return -ENOMEM;
 246
 247         error = bitmap_parselist(buf, bits, n_events);
 248         if (error)
 249                 goto out;
 250
 251         /* First validate */
 252         if (!bitmap_subset(bits, bitmap, n_events)) {
 253                 error = -EINVAL;
 254                 goto out;
 255         }
 256
 257         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 258                 struct gpio_button_data *bdata = &ddata->data[i];
 259
 260                 if (bdata->button->type != type)
 261                         continue;
 262
 263                 if (test_bit(*bdata->code, bits) &&
 264                     !bdata->button->can_disable) {
 265                         error = -EINVAL;
 266                         goto out;
 267                 }
 268         }
 269
 270         mutex_lock(&ddata->disable_lock);
 271
 272         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 273                 struct gpio_button_data *bdata = &ddata->data[i];
 274
 275                 if (bdata->button->type != type)
 276                         continue;
 277
 278                 if (test_bit(*bdata->code, bits))
 279                         gpio_keys_disable_button(bdata);
 280                 else
 281                         gpio_keys_enable_button(bdata);
 282         }
 283
 284         mutex_unlock(&ddata->disable_lock);
 285
 286 out:
 287         bitmap_free(bits);
 288         return error;
 289 }
 290
 291 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
 292 static ssize_t gpio_keys_show_##name(struct device *dev,                \
 293                                      struct device_attribute *attr,     \
 294                                      char *buf)                         \
 295 {                                                                       \
 296         struct platform_device *pdev = to_platform_device(dev);         \
 297         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 298                                                                         \
 299         return gpio_keys_attr_show_helper(ddata, buf,                   \
 300                                           type, only_disabled);         \
 301 }
 302
 303 ATTR_SHOW_FN(keys, EV_KEY, false);
 304 ATTR_SHOW_FN(switches, EV_SW, false);
 305 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
 306 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
 307
 308 /*
 309  * ATTRIBUTES:
 310  *
 311  * /sys/devices/platform/gpio-keys/keys [ro]
 312  * /sys/devices/platform/gpio-keys/switches [ro]
 313  */
 314 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
 315 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
 316
 317 #define ATTR_STORE_FN(name, type)                                       \
 318 static ssize_t gpio_keys_store_##name(struct device *dev,               \
 319                                       struct device_attribute *attr,    \
 320                                       const char *buf,                  \
 321                                       size_t count)                     \
 322 {                                                                       \
 323         struct platform_device *pdev = to_platform_device(dev);         \
 324         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 325         ssize_t error;                                                  \
 326                                                                         \
 327         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
 328         if (error)                                                      \
 329                 return error;                                           \
 330                                                                         \
 331         return count;                                                   \
 332 }
 333
 334 ATTR_STORE_FN(disabled_keys, EV_KEY);
 335 ATTR_STORE_FN(disabled_switches, EV_SW);
 336
 337 /*
 338  * ATTRIBUTES:
 339  *
 340  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
 341  * /sys/devices/platform/gpio-keys/disables_switches [rw]
 342  */
 343 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
 344                    gpio_keys_show_disabled_keys,
 345                    gpio_keys_store_disabled_keys);
 346 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
 347                    gpio_keys_show_disabled_switches,
 348                    gpio_keys_store_disabled_switches);
 349
 350 static struct attribute *gpio_keys_attrs[] = {
 351         &dev_attr_keys.attr,
 352         &dev_attr_switches.attr,
 353         &dev_attr_disabled_keys.attr,
 354         &dev_attr_disabled_switches.attr,
 355         NULL,
 356 };
 357
 358 static const struct attribute_group gpio_keys_attr_group = {
 359         .attrs = gpio_keys_attrs,
 360 };
 361
 362 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
 363 {
 364         const struct gpio_keys_button *button = bdata->button;
 365         struct input_dev *input = bdata->input;
 366         unsigned int type = button->type ?: EV_KEY;
 367         int state;
 368
 369         state = gpiod_get_value_cansleep(bdata->gpiod);
 370         if (state < 0) {
 371                 dev_err(input->dev.parent,
 372                         "failed to get gpio state: %d\n", state);
 373                 return;
 374         }
 375
 376         if (type == EV_ABS) {
 377                 if (state)
 378                         input_event(input, type, button->code, button->value);
 379         } else {
 380                 input_event(input, type, *bdata->code, state);
 381         }
 382         input_sync(input);
 383 }
 384
 385 static void gpio_keys_gpio_work_func(struct work_struct *work)
 386 {
 387         struct gpio_button_data *bdata =
 388                 container_of(work, struct gpio_button_data, work.work);
 389
 390         gpio_keys_gpio_report_event(bdata);
 391
 392         if (bdata->button->wakeup)
 393                 pm_relax(bdata->input->dev.parent);
 394 }
 395
 396 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
 397 {
 398         struct gpio_button_data *bdata = dev_id;
 399
 400         BUG_ON(irq != bdata->irq);
 401
 402         if (bdata->button->wakeup) {
 403                 const struct gpio_keys_button *button = bdata->button;
 404
 405                 pm_stay_awake(bdata->input->dev.parent);
 406                 if (bdata->suspended  &&
 407                     (button->type == 0 || button->type == EV_KEY)) {
 408                         /*
 409                          * Simulate wakeup key press in case the key has
 410                          * already released by the time we got interrupt
 411                          * handler to run.
 412                          */
 413                         input_report_key(bdata->input, button->code, 1);
 414                 }
 415         }
 416
 417         mod_delayed_work(system_wq,
 418                          &bdata->work,
 419                          msecs_to_jiffies(bdata->software_debounce));
 420
 421         return IRQ_HANDLED;
 422 }
 423
 424 static void gpio_keys_irq_timer(struct timer_list *t)
 425 {
 426         struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
 427         struct input_dev *input = bdata->input;
 428         unsigned long flags;
 429
 430         spin_lock_irqsave(&bdata->lock, flags);
 431         if (bdata->key_pressed) {
 432                 input_event(input, EV_KEY, *bdata->code, 0);
 433                 input_sync(input);
 434                 bdata->key_pressed = false;
 435         }
 436         spin_unlock_irqrestore(&bdata->lock, flags);
 437 }
 438
 439 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
 440 {
 441         struct gpio_button_data *bdata = dev_id;
 442         struct input_dev *input = bdata->input;
 443         unsigned long flags;
 444
 445         BUG_ON(irq != bdata->irq);
 446
 447         spin_lock_irqsave(&bdata->lock, flags);
 448
 449         if (!bdata->key_pressed) {
 450                 if (bdata->button->wakeup)
 451                         pm_wakeup_event(bdata->input->dev.parent, 0);
 452
 453                 input_event(input, EV_KEY, *bdata->code, 1);
 454                 input_sync(input);
 455
 456                 if (!bdata->release_delay) {
 457                         input_event(input, EV_KEY, *bdata->code, 0);
 458                         input_sync(input);
 459                         goto out;
 460                 }
 461
 462                 bdata->key_pressed = true;
 463         }
 464
 465         if (bdata->release_delay)
 466                 mod_timer(&bdata->release_timer,
 467                         jiffies + msecs_to_jiffies(bdata->release_delay));
 468 out:
 469         spin_unlock_irqrestore(&bdata->lock, flags);
 470         return IRQ_HANDLED;
 471 }
 472
 473 static void gpio_keys_quiesce_key(void *data)
 474 {
 475         struct gpio_button_data *bdata = data;
 476
 477         if (bdata->gpiod)
 478                 cancel_delayed_work_sync(&bdata->work);
 479         else
 480                 del_timer_sync(&bdata->release_timer);
 481 }
 482
 483 static int gpio_keys_setup_key(struct platform_device *pdev,
 484                                 struct input_dev *input,
 485                                 struct gpio_keys_drvdata *ddata,
 486                                 const struct gpio_keys_button *button,
 487                                 int idx,
 488                                 struct fwnode_handle *child)
 489 {
 490         const char *desc = button->desc ? button->desc : "gpio_keys";
 491         struct device *dev = &pdev->dev;
 492         struct gpio_button_data *bdata = &ddata->data[idx];
 493         irq_handler_t isr;
 494         unsigned long irqflags;
 495         int irq;
 496         int error;
 497
 498         bdata->input = input;
 499         bdata->button = button;
 500         spin_lock_init(&bdata->lock);
 501
 502         if (child) {
 503                 bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL,
 504                                                                 child,
 505                                                                 GPIOD_IN,
 506                                                                 desc);
 507                 if (IS_ERR(bdata->gpiod)) {
 508                         error = PTR_ERR(bdata->gpiod);
 509                         if (error == -ENOENT) {
 510                                 /*
 511                                  * GPIO is optional, we may be dealing with
 512                                  * purely interrupt-driven setup.
 513                                  */
 514                                 bdata->gpiod = NULL;
 515                         } else {
 516                                 if (error != -EPROBE_DEFER)
 517                                         dev_err(dev, "failed to get gpio: %d\n",
 518                                                 error);
 519                                 return error;
 520                         }
 521                 }
 522         } else if (gpio_is_valid(button->gpio)) {
 523                 /*
 524                  * Legacy GPIO number, so request the GPIO here and
 525                  * convert it to descriptor.
 526                  */
 527                 unsigned flags = GPIOF_IN;
 528
 529                 if (button->active_low)
 530                         flags |= GPIOF_ACTIVE_LOW;
 531
 532                 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
 533                 if (error < 0) {
 534                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
 535                                 button->gpio, error);
 536                         return error;
 537                 }
 538
 539                 bdata->gpiod = gpio_to_desc(button->gpio);
 540                 if (!bdata->gpiod)
 541                         return -EINVAL;
 542         }
 543
 544         if (bdata->gpiod) {
 545                 bool active_low = gpiod_is_active_low(bdata->gpiod);
 546
 547                 if (button->debounce_interval) {
 548                         error = gpiod_set_debounce(bdata->gpiod,
 549                                         button->debounce_interval * 1000);
 550                         /* use timer if gpiolib doesn't provide debounce */
 551                         if (error < 0)
 552                                 bdata->software_debounce =
 553                                                 button->debounce_interval;
 554                 }
 555
 556                 if (button->irq) {
 557                         bdata->irq = button->irq;
 558                 } else {
 559                         irq = gpiod_to_irq(bdata->gpiod);
 560                         if (irq < 0) {
 561                                 error = irq;
 562                                 dev_err(dev,
 563                                         "Unable to get irq number for GPIO %d, error %d\n",
 564                                         button->gpio, error);
 565                                 return error;
 566                         }
 567                         bdata->irq = irq;
 568                 }
 569
 570                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
 571
 572                 isr = gpio_keys_gpio_isr;
 573                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 574
 575                 switch (button->wakeup_event_action) {
 576                 case EV_ACT_ASSERTED:
 577                         bdata->wakeup_trigger_type = active_low ?
 578                                 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
 579                         break;
 580                 case EV_ACT_DEASSERTED:
 581                         bdata->wakeup_trigger_type = active_low ?
 582                                 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
 583                         break;
 584                 case EV_ACT_ANY:
 585                         /* fall through */
 586                 default:
 587                         /*
 588                          * For other cases, we are OK letting suspend/resume
 589                          * not reconfigure the trigger type.
 590                          */
 591                         break;
 592                 }
 593         } else {
 594                 if (!button->irq) {
 595                         dev_err(dev, "Found button without gpio or irq\n");
 596                         return -EINVAL;
 597                 }
 598
 599                 bdata->irq = button->irq;
 600
 601                 if (button->type && button->type != EV_KEY) {
 602                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 603                         return -EINVAL;
 604                 }
 605
 606                 bdata->release_delay = button->debounce_interval;
 607                 timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
 608
 609                 isr = gpio_keys_irq_isr;
 610                 irqflags = 0;
 611
 612                 /*
 613                  * For IRQ buttons, there is no interrupt for release.
 614                  * So we don't need to reconfigure the trigger type for wakeup.
 615                  */
 616         }
 617
 618         bdata->code = &ddata->keymap[idx];
 619         *bdata->code = button->code;
 620         input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
 621
 622         /*
 623          * Install custom action to cancel release timer and
 624          * workqueue item.
 625          */
 626         error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
 627         if (error) {
 628                 dev_err(dev, "failed to register quiesce action, error: %d\n",
 629                         error);
 630                 return error;
 631         }
 632
 633         /*
 634          * If platform has specified that the button can be disabled,
 635          * we don't want it to share the interrupt line.
 636          */
 637         if (!button->can_disable)
 638                 irqflags |= IRQF_SHARED;
 639
 640         error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
 641                                              desc, bdata);
 642         if (error < 0) {
 643                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 644                         bdata->irq, error);
 645                 return error;
 646         }
 647
 648         return 0;
 649 }
 650
 651 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 652 {
 653         struct input_dev *input = ddata->input;
 654         int i;
 655
 656         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 657                 struct gpio_button_data *bdata = &ddata->data[i];
 658                 if (bdata->gpiod)
 659                         gpio_keys_gpio_report_event(bdata);
 660         }
 661         input_sync(input);
 662 }
 663
 664 static int gpio_keys_open(struct input_dev *input)
 665 {
 666         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 667         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 668         int error;
 669
 670         if (pdata->enable) {
 671                 error = pdata->enable(input->dev.parent);
 672                 if (error)
 673                         return error;
 674         }
 675
 676         /* Report current state of buttons that are connected to GPIOs */
 677         gpio_keys_report_state(ddata);
 678
 679         return 0;
 680 }
 681
 682 static void gpio_keys_close(struct input_dev *input)
 683 {
 684         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 685         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 686
 687         if (pdata->disable)
 688                 pdata->disable(input->dev.parent);
 689 }
 690
 691 /*
 692  * Handlers for alternative sources of platform_data
 693  */
 694
 695 /*
 696  * Translate properties into platform_data
 697  */
 698 static struct gpio_keys_platform_data *
 699 gpio_keys_get_devtree_pdata(struct device *dev)
 700 {
 701         struct gpio_keys_platform_data *pdata;
 702         struct gpio_keys_button *button;
 703         struct fwnode_handle *child;
 704         int nbuttons;
 705
 706         nbuttons = device_get_child_node_count(dev);
 707         if (nbuttons == 0)
 708                 return ERR_PTR(-ENODEV);
 709
 710         pdata = devm_kzalloc(dev,
 711                              sizeof(*pdata) + nbuttons * sizeof(*button),
 712                              GFP_KERNEL);
 713         if (!pdata)
 714                 return ERR_PTR(-ENOMEM);
 715
 716         button = (struct gpio_keys_button *)(pdata + 1);
 717
 718         pdata->buttons = button;
 719         pdata->nbuttons = nbuttons;
 720
 721         pdata->rep = device_property_read_bool(dev, "autorepeat");
 722
 723         device_property_read_string(dev, "label", &pdata->name);
 724
 725         device_for_each_child_node(dev, child) {
 726                 if (is_of_node(child))
 727                         button->irq =
 728                                 irq_of_parse_and_map(to_of_node(child), 0);
 729
 730                 if (fwnode_property_read_u32(child, "linux,code",
 731                                              &button->code)) {
 732                         dev_err(dev, "Button without keycode\n");
 733                         fwnode_handle_put(child);
 734                         return ERR_PTR(-EINVAL);
 735                 }
 736
 737                 fwnode_property_read_string(child, "label", &button->desc);
 738
 739                 if (fwnode_property_read_u32(child, "linux,input-type",
 740                                              &button->type))
 741                         button->type = EV_KEY;
 742
 743                 button->wakeup =
 744                         fwnode_property_read_bool(child, "wakeup-source") ||
 745                         /* legacy name */
 746                         fwnode_property_read_bool(child, "gpio-key,wakeup");
 747
 748                 fwnode_property_read_u32(child, "wakeup-event-action",
 749                                          &button->wakeup_event_action);
 750
 751                 button->can_disable =
 752                         fwnode_property_read_bool(child, "linux,can-disable");
 753
 754                 if (fwnode_property_read_u32(child, "debounce-interval",
 755                                          &button->debounce_interval))
 756                         button->debounce_interval = 5;
 757
 758                 button++;
 759         }
 760
 761         return pdata;
 762 }
 763
 764 static const struct of_device_id gpio_keys_of_match[] = {
 765         { .compatible = "gpio-keys", },
 766         { },
 767 };
 768 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 769
 770 static int gpio_keys_probe(struct platform_device *pdev)
 771 {
 772         struct device *dev = &pdev->dev;
 773         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 774         struct fwnode_handle *child = NULL;
 775         struct gpio_keys_drvdata *ddata;
 776         struct input_dev *input;
 777         size_t size;
 778         int i, error;
 779         int wakeup = 0;
 780
 781         if (!pdata) {
 782                 pdata = gpio_keys_get_devtree_pdata(dev);
 783                 if (IS_ERR(pdata))
 784                         return PTR_ERR(pdata);
 785         }
 786
 787         size = sizeof(struct gpio_keys_drvdata) +
 788                         pdata->nbuttons * sizeof(struct gpio_button_data);
 789         ddata = devm_kzalloc(dev, size, GFP_KERNEL);
 790         if (!ddata) {
 791                 dev_err(dev, "failed to allocate state\n");
 792                 return -ENOMEM;
 793         }
 794
 795         ddata->keymap = devm_kcalloc(dev,
 796                                      pdata->nbuttons, sizeof(ddata->keymap[0]),
 797                                      GFP_KERNEL);
 798         if (!ddata->keymap)
 799                 return -ENOMEM;
 800
 801         input = devm_input_allocate_device(dev);
 802         if (!input) {
 803                 dev_err(dev, "failed to allocate input device\n");
 804                 return -ENOMEM;
 805         }
 806
 807         ddata->pdata = pdata;
 808         ddata->input = input;
 809         mutex_init(&ddata->disable_lock);
 810
 811         platform_set_drvdata(pdev, ddata);
 812         input_set_drvdata(input, ddata);
 813
 814         input->name = pdata->name ? : pdev->name;
 815         input->phys = "gpio-keys/input0";
 816         input->dev.parent = dev;
 817         input->open = gpio_keys_open;
 818         input->close = gpio_keys_close;
 819
 820         input->id.bustype = BUS_HOST;
 821         input->id.vendor = 0x0001;
 822         input->id.product = 0x0001;
 823         input->id.version = 0x0100;
 824
 825         input->keycode = ddata->keymap;
 826         input->keycodesize = sizeof(ddata->keymap[0]);
 827         input->keycodemax = pdata->nbuttons;
 828
 829         /* Enable auto repeat feature of Linux input subsystem */
 830         if (pdata->rep)
 831                 __set_bit(EV_REP, input->evbit);
 832
 833         for (i = 0; i < pdata->nbuttons; i++) {
 834                 const struct gpio_keys_button *button = &pdata->buttons[i];
 835
 836                 if (!dev_get_platdata(dev)) {
 837                         child = device_get_next_child_node(dev, child);
 838                         if (!child) {
 839                                 dev_err(dev,
 840                                         "missing child device node for entry %d\n",
 841                                         i);
 842                                 return -EINVAL;
 843                         }
 844                 }
 845
 846                 error = gpio_keys_setup_key(pdev, input, ddata,
 847                                             button, i, child);
 848                 if (error) {
 849                         fwnode_handle_put(child);
 850                         return error;
 851                 }
 852
 853                 if (button->wakeup)
 854                         wakeup = 1;
 855         }
 856
 857         fwnode_handle_put(child);
 858
 859         error = devm_device_add_group(dev, &gpio_keys_attr_group);
 860         if (error) {
 861                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
 862                         error);
 863                 return error;
 864         }
 865
 866         error = input_register_device(input);
 867         if (error) {
 868                 dev_err(dev, "Unable to register input device, error: %d\n",
 869                         error);
 870                 return error;
 871         }
 872
 873         device_init_wakeup(dev, wakeup);
 874
 875         return 0;
 876 }
 877
 878 static int __maybe_unused
 879 gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
 880 {
 881         int error;
 882
 883         error = enable_irq_wake(bdata->irq);
 884         if (error) {
 885                 dev_err(bdata->input->dev.parent,
 886                         "failed to configure IRQ %d as wakeup source: %d\n",
 887                         bdata->irq, error);
 888                 return error;
 889         }
 890
 891         if (bdata->wakeup_trigger_type) {
 892                 error = irq_set_irq_type(bdata->irq,
 893                                          bdata->wakeup_trigger_type);
 894                 if (error) {
 895                         dev_err(bdata->input->dev.parent,
 896                                 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
 897                                 bdata->wakeup_trigger_type, bdata->irq, error);
 898                         disable_irq_wake(bdata->irq);
 899                         return error;
 900                 }
 901         }
 902
 903         return 0;
 904 }
 905
 906 static void __maybe_unused
 907 gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
 908 {
 909         int error;
 910
 911         /*
 912          * The trigger type is always both edges for gpio-based keys and we do
 913          * not support changing wakeup trigger for interrupt-based keys.
 914          */
 915         if (bdata->wakeup_trigger_type) {
 916                 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
 917                 if (error)
 918                         dev_warn(bdata->input->dev.parent,
 919                                  "failed to restore interrupt trigger for IRQ %d: %d\n",
 920                                  bdata->irq, error);
 921         }
 922
 923         error = disable_irq_wake(bdata->irq);
 924         if (error)
 925                 dev_warn(bdata->input->dev.parent,
 926                          "failed to disable IRQ %d as wake source: %d\n",
 927                          bdata->irq, error);
 928 }
 929
 930 static int __maybe_unused
 931 gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
 932 {
 933         struct gpio_button_data *bdata;
 934         int error;
 935         int i;
 936
 937         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 938                 bdata = &ddata->data[i];
 939                 if (bdata->button->wakeup) {
 940                         error = gpio_keys_button_enable_wakeup(bdata);
 941                         if (error)
 942                                 goto err_out;
 943                 }
 944                 bdata->suspended = true;
 945         }
 946
 947         return 0;
 948
 949 err_out:
 950         while (i--) {
 951                 bdata = &ddata->data[i];
 952                 if (bdata->button->wakeup)
 953                         gpio_keys_button_disable_wakeup(bdata);
 954                 bdata->suspended = false;
 955         }
 956
 957         return error;
 958 }
 959
 960 static void __maybe_unused
 961 gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
 962 {
 963         struct gpio_button_data *bdata;
 964         int i;
 965
 966         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 967                 bdata = &ddata->data[i];
 968                 bdata->suspended = false;
 969                 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
 970                         gpio_keys_button_disable_wakeup(bdata);
 971         }
 972 }
 973
 974 static int __maybe_unused gpio_keys_suspend(struct device *dev)
 975 {
 976         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 977         struct input_dev *input = ddata->input;
 978         int error;
 979
 980         if (device_may_wakeup(dev)) {
 981                 error = gpio_keys_enable_wakeup(ddata);
 982                 if (error)
 983                         return error;
 984         } else {
 985                 mutex_lock(&input->mutex);
 986                 if (input->users)
 987                         gpio_keys_close(input);
 988                 mutex_unlock(&input->mutex);
 989         }
 990
 991         return 0;
 992 }
 993
 994 static int __maybe_unused gpio_keys_resume(struct device *dev)
 995 {
 996         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 997         struct input_dev *input = ddata->input;
 998         int error = 0;
 999
1000         if (device_may_wakeup(dev)) {
1001                 gpio_keys_disable_wakeup(ddata);
1002         } else {
1003                 mutex_lock(&input->mutex);
1004                 if (input->users)
1005                         error = gpio_keys_open(input);
1006                 mutex_unlock(&input->mutex);
1007         }
1008
1009         if (error)
1010                 return error;
1011
1012         gpio_keys_report_state(ddata);
1013         return 0;
1014 }
1015
1016 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1017
1018 static struct platform_driver gpio_keys_device_driver = {
1019         .probe          = gpio_keys_probe,
1020         .driver         = {
1021                 .name   = "gpio-keys",
1022                 .pm     = &gpio_keys_pm_ops,
1023                 .of_match_table = gpio_keys_of_match,
1024         }
1025 };
1026
1027 static int __init gpio_keys_init(void)
1028 {
1029         return platform_driver_register(&gpio_keys_device_driver);
1030 }
1031
1032 static void __exit gpio_keys_exit(void)
1033 {
1034         platform_driver_unregister(&gpio_keys_device_driver);
1035 }
1036
1037 late_initcall(gpio_keys_init);
1038 module_exit(gpio_keys_exit);
1039
1040 MODULE_LICENSE("GPL");
1041 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1042 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1043 MODULE_ALIAS("platform:gpio-keys");