drivers/input/keyboard/gpio_keys.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for keys on GPIO lines capable of generating interrupts.
   4  *
   5  * Copyright 2005 Phil Blundell
   6  * Copyright 2010, 2011 David Jander <david@protonic.nl>
   7  */
   8
   9 #include <linux/module.h>
  10
  11 #include <linux/init.h>
  12 #include <linux/fs.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <linux/sched.h>
  16 #include <linux/pm.h>
  17 #include <linux/slab.h>
  18 #include <linux/sysctl.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/delay.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/input.h>
  23 #include <linux/gpio_keys.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/gpio.h>
  26 #include <linux/gpio/consumer.h>
  27 #include <linux/of.h>
  28 #include <linux/of_irq.h>
  29 #include <linux/spinlock.h>
  30 #include <dt-bindings/input/gpio-keys.h>
  31
  32 struct gpio_button_data {
  33         const struct gpio_keys_button *button;
  34         struct input_dev *input;
  35         struct gpio_desc *gpiod;
  36
  37         unsigned short *code;
  38
  39         struct timer_list release_timer;
  40         unsigned int release_delay;     /* in msecs, for IRQ-only buttons */
  41
  42         struct delayed_work work;
  43         unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
  44
  45         unsigned int irq;
  46         unsigned int wakeup_trigger_type;
  47         spinlock_t lock;
  48         bool disabled;
  49         bool key_pressed;
  50         bool suspended;
  51 };
  52
  53 struct gpio_keys_drvdata {
  54         const struct gpio_keys_platform_data *pdata;
  55         struct input_dev *input;
  56         struct mutex disable_lock;
  57         unsigned short *keymap;
  58         struct gpio_button_data data[];
  59 };
  60
  61 /*
  62  * SYSFS interface for enabling/disabling keys and switches:
  63  *
  64  * There are 4 attributes under /sys/devices/platform/gpio-keys/
  65  *      keys [ro]              - bitmap of keys (EV_KEY) which can be
  66  *                               disabled
  67  *      switches [ro]          - bitmap of switches (EV_SW) which can be
  68  *                               disabled
  69  *      disabled_keys [rw]     - bitmap of keys currently disabled
  70  *      disabled_switches [rw] - bitmap of switches currently disabled
  71  *
  72  * Userland can change these values and hence disable event generation
  73  * for each key (or switch). Disabling a key means its interrupt line
  74  * is disabled.
  75  *
  76  * For example, if we have following switches set up as gpio-keys:
  77  *      SW_DOCK = 5
  78  *      SW_CAMERA_LENS_COVER = 9
  79  *      SW_KEYPAD_SLIDE = 10
  80  *      SW_FRONT_PROXIMITY = 11
  81  * This is read from switches:
  82  *      11-9,5
  83  * Next we want to disable proximity (11) and dock (5), we write:
  84  *      11,5
  85  * to file disabled_switches. Now proximity and dock IRQs are disabled.
  86  * This can be verified by reading the file disabled_switches:
  87  *      11,5
  88  * If we now want to enable proximity (11) switch we write:
  89  *      5
  90  * to disabled_switches.
  91  *
  92  * We can disable only those keys which don't allow sharing the irq.
  93  */
  94
  95 /**
  96  * get_n_events_by_type() - returns maximum number of events per @type
  97  * @type: type of button (%EV_KEY, %EV_SW)
  98  *
  99  * Return value of this function can be used to allocate bitmap
 100  * large enough to hold all bits for given type.
 101  */
 102 static int get_n_events_by_type(int type)
 103 {
 104         BUG_ON(type != EV_SW && type != EV_KEY);
 105
 106         return (type == EV_KEY) ? KEY_CNT : SW_CNT;
 107 }
 108
 109 /**
 110  * get_bm_events_by_type() - returns bitmap of supported events per @type
 111  * @input: input device from which bitmap is retrieved
 112  * @type: type of button (%EV_KEY, %EV_SW)
 113  *
 114  * Return value of this function can be used to allocate bitmap
 115  * large enough to hold all bits for given type.
 116  */
 117 static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
 118                                                   int type)
 119 {
 120         BUG_ON(type != EV_SW && type != EV_KEY);
 121
 122         return (type == EV_KEY) ? dev->keybit : dev->swbit;
 123 }
 124
 125 /**
 126  * gpio_keys_disable_button() - disables given GPIO button
 127  * @bdata: button data for button to be disabled
 128  *
 129  * Disables button pointed by @bdata. This is done by masking
 130  * IRQ line. After this function is called, button won't generate
 131  * input events anymore. Note that one can only disable buttons
 132  * that don't share IRQs.
 133  *
 134  * Make sure that @bdata->disable_lock is locked when entering
 135  * this function to avoid races when concurrent threads are
 136  * disabling buttons at the same time.
 137  */
 138 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
 139 {
 140         if (!bdata->disabled) {
 141                 /*
 142                  * Disable IRQ and associated timer/work structure.
 143                  */
 144                 disable_irq(bdata->irq);
 145
 146                 if (bdata->gpiod)
 147                         cancel_delayed_work_sync(&bdata->work);
 148                 else
 149                         del_timer_sync(&bdata->release_timer);
 150
 151                 bdata->disabled = true;
 152         }
 153 }
 154
 155 /**
 156  * gpio_keys_enable_button() - enables given GPIO button
 157  * @bdata: button data for button to be disabled
 158  *
 159  * Enables given button pointed by @bdata.
 160  *
 161  * Make sure that @bdata->disable_lock is locked when entering
 162  * this function to avoid races with concurrent threads trying
 163  * to enable the same button at the same time.
 164  */
 165 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
 166 {
 167         if (bdata->disabled) {
 168                 enable_irq(bdata->irq);
 169                 bdata->disabled = false;
 170         }
 171 }
 172
 173 /**
 174  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
 175  * @ddata: pointer to drvdata
 176  * @buf: buffer where stringified bitmap is written
 177  * @type: button type (%EV_KEY, %EV_SW)
 178  * @only_disabled: does caller want only those buttons that are
 179  *                 currently disabled or all buttons that can be
 180  *                 disabled
 181  *
 182  * This function writes buttons that can be disabled to @buf. If
 183  * @only_disabled is true, then @buf contains only those buttons
 184  * that are currently disabled. Returns 0 on success or negative
 185  * errno on failure.
 186  */
 187 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
 188                                           char *buf, unsigned int type,
 189                                           bool only_disabled)
 190 {
 191         int n_events = get_n_events_by_type(type);
 192         unsigned long *bits;
 193         ssize_t ret;
 194         int i;
 195
 196         bits = bitmap_zalloc(n_events, GFP_KERNEL);
 197         if (!bits)
 198                 return -ENOMEM;
 199
 200         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 201                 struct gpio_button_data *bdata = &ddata->data[i];
 202
 203                 if (bdata->button->type != type)
 204                         continue;
 205
 206                 if (only_disabled && !bdata->disabled)
 207                         continue;
 208
 209                 __set_bit(*bdata->code, bits);
 210         }
 211
 212         ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
 213         buf[ret++] = '\n';
 214         buf[ret] = '\0';
 215
 216         bitmap_free(bits);
 217
 218         return ret;
 219 }
 220
 221 /**
 222  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
 223  * @ddata: pointer to drvdata
 224  * @buf: buffer from userspace that contains stringified bitmap
 225  * @type: button type (%EV_KEY, %EV_SW)
 226  *
 227  * This function parses stringified bitmap from @buf and disables/enables
 228  * GPIO buttons accordingly. Returns 0 on success and negative error
 229  * on failure.
 230  */
 231 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 232                                            const char *buf, unsigned int type)
 233 {
 234         int n_events = get_n_events_by_type(type);
 235         const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
 236         unsigned long *bits;
 237         ssize_t error;
 238         int i;
 239
 240         bits = bitmap_zalloc(n_events, GFP_KERNEL);
 241         if (!bits)
 242                 return -ENOMEM;
 243
 244         error = bitmap_parselist(buf, bits, n_events);
 245         if (error)
 246                 goto out;
 247
 248         /* First validate */
 249         if (!bitmap_subset(bits, bitmap, n_events)) {
 250                 error = -EINVAL;
 251                 goto out;
 252         }
 253
 254         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 255                 struct gpio_button_data *bdata = &ddata->data[i];
 256
 257                 if (bdata->button->type != type)
 258                         continue;
 259
 260                 if (test_bit(*bdata->code, bits) &&
 261                     !bdata->button->can_disable) {
 262                         error = -EINVAL;
 263                         goto out;
 264                 }
 265         }
 266
 267         mutex_lock(&ddata->disable_lock);
 268
 269         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 270                 struct gpio_button_data *bdata = &ddata->data[i];
 271
 272                 if (bdata->button->type != type)
 273                         continue;
 274
 275                 if (test_bit(*bdata->code, bits))
 276                         gpio_keys_disable_button(bdata);
 277                 else
 278                         gpio_keys_enable_button(bdata);
 279         }
 280
 281         mutex_unlock(&ddata->disable_lock);
 282
 283 out:
 284         bitmap_free(bits);
 285         return error;
 286 }
 287
 288 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
 289 static ssize_t gpio_keys_show_##name(struct device *dev,                \
 290                                      struct device_attribute *attr,     \
 291                                      char *buf)                         \
 292 {                                                                       \
 293         struct platform_device *pdev = to_platform_device(dev);         \
 294         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 295                                                                         \
 296         return gpio_keys_attr_show_helper(ddata, buf,                   \
 297                                           type, only_disabled);         \
 298 }
 299
 300 ATTR_SHOW_FN(keys, EV_KEY, false);
 301 ATTR_SHOW_FN(switches, EV_SW, false);
 302 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
 303 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
 304
 305 /*
 306  * ATTRIBUTES:
 307  *
 308  * /sys/devices/platform/gpio-keys/keys [ro]
 309  * /sys/devices/platform/gpio-keys/switches [ro]
 310  */
 311 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
 312 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
 313
 314 #define ATTR_STORE_FN(name, type)                                       \
 315 static ssize_t gpio_keys_store_##name(struct device *dev,               \
 316                                       struct device_attribute *attr,    \
 317                                       const char *buf,                  \
 318                                       size_t count)                     \
 319 {                                                                       \
 320         struct platform_device *pdev = to_platform_device(dev);         \
 321         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
 322         ssize_t error;                                                  \
 323                                                                         \
 324         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
 325         if (error)                                                      \
 326                 return error;                                           \
 327                                                                         \
 328         return count;                                                   \
 329 }
 330
 331 ATTR_STORE_FN(disabled_keys, EV_KEY);
 332 ATTR_STORE_FN(disabled_switches, EV_SW);
 333
 334 /*
 335  * ATTRIBUTES:
 336  *
 337  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
 338  * /sys/devices/platform/gpio-keys/disables_switches [rw]
 339  */
 340 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
 341                    gpio_keys_show_disabled_keys,
 342                    gpio_keys_store_disabled_keys);
 343 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
 344                    gpio_keys_show_disabled_switches,
 345                    gpio_keys_store_disabled_switches);
 346
 347 static struct attribute *gpio_keys_attrs[] = {
 348         &dev_attr_keys.attr,
 349         &dev_attr_switches.attr,
 350         &dev_attr_disabled_keys.attr,
 351         &dev_attr_disabled_switches.attr,
 352         NULL,
 353 };
 354 ATTRIBUTE_GROUPS(gpio_keys);
 355
 356 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
 357 {
 358         const struct gpio_keys_button *button = bdata->button;
 359         struct input_dev *input = bdata->input;
 360         unsigned int type = button->type ?: EV_KEY;
 361         int state;
 362
 363         state = gpiod_get_value_cansleep(bdata->gpiod);
 364         if (state < 0) {
 365                 dev_err(input->dev.parent,
 366                         "failed to get gpio state: %d\n", state);
 367                 return;
 368         }
 369
 370         if (type == EV_ABS) {
 371                 if (state)
 372                         input_event(input, type, button->code, button->value);
 373         } else {
 374                 input_event(input, type, *bdata->code, state);
 375         }
 376         input_sync(input);
 377 }
 378
 379 static void gpio_keys_gpio_work_func(struct work_struct *work)
 380 {
 381         struct gpio_button_data *bdata =
 382                 container_of(work, struct gpio_button_data, work.work);
 383
 384         gpio_keys_gpio_report_event(bdata);
 385
 386         if (bdata->button->wakeup)
 387                 pm_relax(bdata->input->dev.parent);
 388 }
 389
 390 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
 391 {
 392         struct gpio_button_data *bdata = dev_id;
 393
 394         BUG_ON(irq != bdata->irq);
 395
 396         if (bdata->button->wakeup) {
 397                 const struct gpio_keys_button *button = bdata->button;
 398
 399                 pm_stay_awake(bdata->input->dev.parent);
 400                 if (bdata->suspended  &&
 401                     (button->type == 0 || button->type == EV_KEY)) {
 402                         /*
 403                          * Simulate wakeup key press in case the key has
 404                          * already released by the time we got interrupt
 405                          * handler to run.
 406                          */
 407                         input_report_key(bdata->input, button->code, 1);
 408                 }
 409         }
 410
 411         mod_delayed_work(system_wq,
 412                          &bdata->work,
 413                          msecs_to_jiffies(bdata->software_debounce));
 414
 415         return IRQ_HANDLED;
 416 }
 417
 418 static void gpio_keys_irq_timer(struct timer_list *t)
 419 {
 420         struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
 421         struct input_dev *input = bdata->input;
 422         unsigned long flags;
 423
 424         spin_lock_irqsave(&bdata->lock, flags);
 425         if (bdata->key_pressed) {
 426                 input_event(input, EV_KEY, *bdata->code, 0);
 427                 input_sync(input);
 428                 bdata->key_pressed = false;
 429         }
 430         spin_unlock_irqrestore(&bdata->lock, flags);
 431 }
 432
 433 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
 434 {
 435         struct gpio_button_data *bdata = dev_id;
 436         struct input_dev *input = bdata->input;
 437         unsigned long flags;
 438
 439         BUG_ON(irq != bdata->irq);
 440
 441         spin_lock_irqsave(&bdata->lock, flags);
 442
 443         if (!bdata->key_pressed) {
 444                 if (bdata->button->wakeup)
 445                         pm_wakeup_event(bdata->input->dev.parent, 0);
 446
 447                 input_event(input, EV_KEY, *bdata->code, 1);
 448                 input_sync(input);
 449
 450                 if (!bdata->release_delay) {
 451                         input_event(input, EV_KEY, *bdata->code, 0);
 452                         input_sync(input);
 453                         goto out;
 454                 }
 455
 456                 bdata->key_pressed = true;
 457         }
 458
 459         if (bdata->release_delay)
 460                 mod_timer(&bdata->release_timer,
 461                         jiffies + msecs_to_jiffies(bdata->release_delay));
 462 out:
 463         spin_unlock_irqrestore(&bdata->lock, flags);
 464         return IRQ_HANDLED;
 465 }
 466
 467 static void gpio_keys_quiesce_key(void *data)
 468 {
 469         struct gpio_button_data *bdata = data;
 470
 471         if (bdata->gpiod)
 472                 cancel_delayed_work_sync(&bdata->work);
 473         else
 474                 del_timer_sync(&bdata->release_timer);
 475 }
 476
 477 static int gpio_keys_setup_key(struct platform_device *pdev,
 478                                 struct input_dev *input,
 479                                 struct gpio_keys_drvdata *ddata,
 480                                 const struct gpio_keys_button *button,
 481                                 int idx,
 482                                 struct fwnode_handle *child)
 483 {
 484         const char *desc = button->desc ? button->desc : "gpio_keys";
 485         struct device *dev = &pdev->dev;
 486         struct gpio_button_data *bdata = &ddata->data[idx];
 487         irq_handler_t isr;
 488         unsigned long irqflags;
 489         int irq;
 490         int error;
 491
 492         bdata->input = input;
 493         bdata->button = button;
 494         spin_lock_init(&bdata->lock);
 495
 496         if (child) {
 497                 bdata->gpiod = devm_fwnode_gpiod_get(dev, child,
 498                                                      NULL, GPIOD_IN, desc);
 499                 if (IS_ERR(bdata->gpiod)) {
 500                         error = PTR_ERR(bdata->gpiod);
 501                         if (error == -ENOENT) {
 502                                 /*
 503                                  * GPIO is optional, we may be dealing with
 504                                  * purely interrupt-driven setup.
 505                                  */
 506                                 bdata->gpiod = NULL;
 507                         } else {
 508                                 if (error != -EPROBE_DEFER)
 509                                         dev_err(dev, "failed to get gpio: %d\n",
 510                                                 error);
 511                                 return error;
 512                         }
 513                 }
 514         } else if (gpio_is_valid(button->gpio)) {
 515                 /*
 516                  * Legacy GPIO number, so request the GPIO here and
 517                  * convert it to descriptor.
 518                  */
 519                 unsigned flags = GPIOF_IN;
 520
 521                 if (button->active_low)
 522                         flags |= GPIOF_ACTIVE_LOW;
 523
 524                 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
 525                 if (error < 0) {
 526                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
 527                                 button->gpio, error);
 528                         return error;
 529                 }
 530
 531                 bdata->gpiod = gpio_to_desc(button->gpio);
 532                 if (!bdata->gpiod)
 533                         return -EINVAL;
 534         }
 535
 536         if (bdata->gpiod) {
 537                 bool active_low = gpiod_is_active_low(bdata->gpiod);
 538
 539                 if (button->debounce_interval) {
 540                         error = gpiod_set_debounce(bdata->gpiod,
 541                                         button->debounce_interval * 1000);
 542                         /* use timer if gpiolib doesn't provide debounce */
 543                         if (error < 0)
 544                                 bdata->software_debounce =
 545                                                 button->debounce_interval;
 546                 }
 547
 548                 if (button->irq) {
 549                         bdata->irq = button->irq;
 550                 } else {
 551                         irq = gpiod_to_irq(bdata->gpiod);
 552                         if (irq < 0) {
 553                                 error = irq;
 554                                 dev_err(dev,
 555                                         "Unable to get irq number for GPIO %d, error %d\n",
 556                                         button->gpio, error);
 557                                 return error;
 558                         }
 559                         bdata->irq = irq;
 560                 }
 561
 562                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
 563
 564                 isr = gpio_keys_gpio_isr;
 565                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 566
 567                 switch (button->wakeup_event_action) {
 568                 case EV_ACT_ASSERTED:
 569                         bdata->wakeup_trigger_type = active_low ?
 570                                 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
 571                         break;
 572                 case EV_ACT_DEASSERTED:
 573                         bdata->wakeup_trigger_type = active_low ?
 574                                 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
 575                         break;
 576                 case EV_ACT_ANY:
 577                         /* fall through */
 578                 default:
 579                         /*
 580                          * For other cases, we are OK letting suspend/resume
 581                          * not reconfigure the trigger type.
 582                          */
 583                         break;
 584                 }
 585         } else {
 586                 if (!button->irq) {
 587                         dev_err(dev, "Found button without gpio or irq\n");
 588                         return -EINVAL;
 589                 }
 590
 591                 bdata->irq = button->irq;
 592
 593                 if (button->type && button->type != EV_KEY) {
 594                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 595                         return -EINVAL;
 596                 }
 597
 598                 bdata->release_delay = button->debounce_interval;
 599                 timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
 600
 601                 isr = gpio_keys_irq_isr;
 602                 irqflags = 0;
 603
 604                 /*
 605                  * For IRQ buttons, there is no interrupt for release.
 606                  * So we don't need to reconfigure the trigger type for wakeup.
 607                  */
 608         }
 609
 610         bdata->code = &ddata->keymap[idx];
 611         *bdata->code = button->code;
 612         input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
 613
 614         /*
 615          * Install custom action to cancel release timer and
 616          * workqueue item.
 617          */
 618         error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
 619         if (error) {
 620                 dev_err(dev, "failed to register quiesce action, error: %d\n",
 621                         error);
 622                 return error;
 623         }
 624
 625         /*
 626          * If platform has specified that the button can be disabled,
 627          * we don't want it to share the interrupt line.
 628          */
 629         if (!button->can_disable)
 630                 irqflags |= IRQF_SHARED;
 631
 632         error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
 633                                              desc, bdata);
 634         if (error < 0) {
 635                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 636                         bdata->irq, error);
 637                 return error;
 638         }
 639
 640         return 0;
 641 }
 642
 643 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 644 {
 645         struct input_dev *input = ddata->input;
 646         int i;
 647
 648         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 649                 struct gpio_button_data *bdata = &ddata->data[i];
 650                 if (bdata->gpiod)
 651                         gpio_keys_gpio_report_event(bdata);
 652         }
 653         input_sync(input);
 654 }
 655
 656 static int gpio_keys_open(struct input_dev *input)
 657 {
 658         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 659         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 660         int error;
 661
 662         if (pdata->enable) {
 663                 error = pdata->enable(input->dev.parent);
 664                 if (error)
 665                         return error;
 666         }
 667
 668         /* Report current state of buttons that are connected to GPIOs */
 669         gpio_keys_report_state(ddata);
 670
 671         return 0;
 672 }
 673
 674 static void gpio_keys_close(struct input_dev *input)
 675 {
 676         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 677         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 678
 679         if (pdata->disable)
 680                 pdata->disable(input->dev.parent);
 681 }
 682
 683 /*
 684  * Handlers for alternative sources of platform_data
 685  */
 686
 687 /*
 688  * Translate properties into platform_data
 689  */
 690 static struct gpio_keys_platform_data *
 691 gpio_keys_get_devtree_pdata(struct device *dev)
 692 {
 693         struct gpio_keys_platform_data *pdata;
 694         struct gpio_keys_button *button;
 695         struct fwnode_handle *child;
 696         int nbuttons;
 697
 698         nbuttons = device_get_child_node_count(dev);
 699         if (nbuttons == 0)
 700                 return ERR_PTR(-ENODEV);
 701
 702         pdata = devm_kzalloc(dev,
 703                              sizeof(*pdata) + nbuttons * sizeof(*button),
 704                              GFP_KERNEL);
 705         if (!pdata)
 706                 return ERR_PTR(-ENOMEM);
 707
 708         button = (struct gpio_keys_button *)(pdata + 1);
 709
 710         pdata->buttons = button;
 711         pdata->nbuttons = nbuttons;
 712
 713         pdata->rep = device_property_read_bool(dev, "autorepeat");
 714
 715         device_property_read_string(dev, "label", &pdata->name);
 716
 717         device_for_each_child_node(dev, child) {
 718                 if (is_of_node(child))
 719                         button->irq =
 720                                 irq_of_parse_and_map(to_of_node(child), 0);
 721
 722                 if (fwnode_property_read_u32(child, "linux,code",
 723                                              &button->code)) {
 724                         dev_err(dev, "Button without keycode\n");
 725                         fwnode_handle_put(child);
 726                         return ERR_PTR(-EINVAL);
 727                 }
 728
 729                 fwnode_property_read_string(child, "label", &button->desc);
 730
 731                 if (fwnode_property_read_u32(child, "linux,input-type",
 732                                              &button->type))
 733                         button->type = EV_KEY;
 734
 735                 button->wakeup =
 736                         fwnode_property_read_bool(child, "wakeup-source") ||
 737                         /* legacy name */
 738                         fwnode_property_read_bool(child, "gpio-key,wakeup");
 739
 740                 fwnode_property_read_u32(child, "wakeup-event-action",
 741                                          &button->wakeup_event_action);
 742
 743                 button->can_disable =
 744                         fwnode_property_read_bool(child, "linux,can-disable");
 745
 746                 if (fwnode_property_read_u32(child, "debounce-interval",
 747                                          &button->debounce_interval))
 748                         button->debounce_interval = 5;
 749
 750                 button++;
 751         }
 752
 753         return pdata;
 754 }
 755
 756 static const struct of_device_id gpio_keys_of_match[] = {
 757         { .compatible = "gpio-keys", },
 758         { },
 759 };
 760 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 761
 762 static int gpio_keys_probe(struct platform_device *pdev)
 763 {
 764         struct device *dev = &pdev->dev;
 765         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 766         struct fwnode_handle *child = NULL;
 767         struct gpio_keys_drvdata *ddata;
 768         struct input_dev *input;
 769         int i, error;
 770         int wakeup = 0;
 771
 772         if (!pdata) {
 773                 pdata = gpio_keys_get_devtree_pdata(dev);
 774                 if (IS_ERR(pdata))
 775                         return PTR_ERR(pdata);
 776         }
 777
 778         ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
 779                              GFP_KERNEL);
 780         if (!ddata) {
 781                 dev_err(dev, "failed to allocate state\n");
 782                 return -ENOMEM;
 783         }
 784
 785         ddata->keymap = devm_kcalloc(dev,
 786                                      pdata->nbuttons, sizeof(ddata->keymap[0]),
 787                                      GFP_KERNEL);
 788         if (!ddata->keymap)
 789                 return -ENOMEM;
 790
 791         input = devm_input_allocate_device(dev);
 792         if (!input) {
 793                 dev_err(dev, "failed to allocate input device\n");
 794                 return -ENOMEM;
 795         }
 796
 797         ddata->pdata = pdata;
 798         ddata->input = input;
 799         mutex_init(&ddata->disable_lock);
 800
 801         platform_set_drvdata(pdev, ddata);
 802         input_set_drvdata(input, ddata);
 803
 804         input->name = pdata->name ? : pdev->name;
 805         input->phys = "gpio-keys/input0";
 806         input->dev.parent = dev;
 807         input->open = gpio_keys_open;
 808         input->close = gpio_keys_close;
 809
 810         input->id.bustype = BUS_HOST;
 811         input->id.vendor = 0x0001;
 812         input->id.product = 0x0001;
 813         input->id.version = 0x0100;
 814
 815         input->keycode = ddata->keymap;
 816         input->keycodesize = sizeof(ddata->keymap[0]);
 817         input->keycodemax = pdata->nbuttons;
 818
 819         /* Enable auto repeat feature of Linux input subsystem */
 820         if (pdata->rep)
 821                 __set_bit(EV_REP, input->evbit);
 822
 823         for (i = 0; i < pdata->nbuttons; i++) {
 824                 const struct gpio_keys_button *button = &pdata->buttons[i];
 825
 826                 if (!dev_get_platdata(dev)) {
 827                         child = device_get_next_child_node(dev, child);
 828                         if (!child) {
 829                                 dev_err(dev,
 830                                         "missing child device node for entry %d\n",
 831                                         i);
 832                                 return -EINVAL;
 833                         }
 834                 }
 835
 836                 error = gpio_keys_setup_key(pdev, input, ddata,
 837                                             button, i, child);
 838                 if (error) {
 839                         fwnode_handle_put(child);
 840                         return error;
 841                 }
 842
 843                 if (button->wakeup)
 844                         wakeup = 1;
 845         }
 846
 847         fwnode_handle_put(child);
 848
 849         error = input_register_device(input);
 850         if (error) {
 851                 dev_err(dev, "Unable to register input device, error: %d\n",
 852                         error);
 853                 return error;
 854         }
 855
 856         device_init_wakeup(dev, wakeup);
 857
 858         return 0;
 859 }
 860
 861 static int __maybe_unused
 862 gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
 863 {
 864         int error;
 865
 866         error = enable_irq_wake(bdata->irq);
 867         if (error) {
 868                 dev_err(bdata->input->dev.parent,
 869                         "failed to configure IRQ %d as wakeup source: %d\n",
 870                         bdata->irq, error);
 871                 return error;
 872         }
 873
 874         if (bdata->wakeup_trigger_type) {
 875                 error = irq_set_irq_type(bdata->irq,
 876                                          bdata->wakeup_trigger_type);
 877                 if (error) {
 878                         dev_err(bdata->input->dev.parent,
 879                                 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
 880                                 bdata->wakeup_trigger_type, bdata->irq, error);
 881                         disable_irq_wake(bdata->irq);
 882                         return error;
 883                 }
 884         }
 885
 886         return 0;
 887 }
 888
 889 static void __maybe_unused
 890 gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
 891 {
 892         int error;
 893
 894         /*
 895          * The trigger type is always both edges for gpio-based keys and we do
 896          * not support changing wakeup trigger for interrupt-based keys.
 897          */
 898         if (bdata->wakeup_trigger_type) {
 899                 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
 900                 if (error)
 901                         dev_warn(bdata->input->dev.parent,
 902                                  "failed to restore interrupt trigger for IRQ %d: %d\n",
 903                                  bdata->irq, error);
 904         }
 905
 906         error = disable_irq_wake(bdata->irq);
 907         if (error)
 908                 dev_warn(bdata->input->dev.parent,
 909                          "failed to disable IRQ %d as wake source: %d\n",
 910                          bdata->irq, error);
 911 }
 912
 913 static int __maybe_unused
 914 gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
 915 {
 916         struct gpio_button_data *bdata;
 917         int error;
 918         int i;
 919
 920         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 921                 bdata = &ddata->data[i];
 922                 if (bdata->button->wakeup) {
 923                         error = gpio_keys_button_enable_wakeup(bdata);
 924                         if (error)
 925                                 goto err_out;
 926                 }
 927                 bdata->suspended = true;
 928         }
 929
 930         return 0;
 931
 932 err_out:
 933         while (i--) {
 934                 bdata = &ddata->data[i];
 935                 if (bdata->button->wakeup)
 936                         gpio_keys_button_disable_wakeup(bdata);
 937                 bdata->suspended = false;
 938         }
 939
 940         return error;
 941 }
 942
 943 static void __maybe_unused
 944 gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
 945 {
 946         struct gpio_button_data *bdata;
 947         int i;
 948
 949         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 950                 bdata = &ddata->data[i];
 951                 bdata->suspended = false;
 952                 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
 953                         gpio_keys_button_disable_wakeup(bdata);
 954         }
 955 }
 956
 957 static int __maybe_unused gpio_keys_suspend(struct device *dev)
 958 {
 959         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 960         struct input_dev *input = ddata->input;
 961         int error;
 962
 963         if (device_may_wakeup(dev)) {
 964                 error = gpio_keys_enable_wakeup(ddata);
 965                 if (error)
 966                         return error;
 967         } else {
 968                 mutex_lock(&input->mutex);
 969                 if (input->users)
 970                         gpio_keys_close(input);
 971                 mutex_unlock(&input->mutex);
 972         }
 973
 974         return 0;
 975 }
 976
 977 static int __maybe_unused gpio_keys_resume(struct device *dev)
 978 {
 979         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 980         struct input_dev *input = ddata->input;
 981         int error = 0;
 982
 983         if (device_may_wakeup(dev)) {
 984                 gpio_keys_disable_wakeup(ddata);
 985         } else {
 986                 mutex_lock(&input->mutex);
 987                 if (input->users)
 988                         error = gpio_keys_open(input);
 989                 mutex_unlock(&input->mutex);
 990         }
 991
 992         if (error)
 993                 return error;
 994
 995         gpio_keys_report_state(ddata);
 996         return 0;
 997 }
 998
 999 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1000
1001 static void gpio_keys_shutdown(struct platform_device *pdev)
1002 {
1003         int ret;
1004
1005         ret = gpio_keys_suspend(&pdev->dev);
1006         if (ret)
1007                 dev_err(&pdev->dev, "failed to shutdown\n");
1008 }
1009
1010 static struct platform_driver gpio_keys_device_driver = {
1011         .probe          = gpio_keys_probe,
1012         .shutdown       = gpio_keys_shutdown,
1013         .driver         = {
1014                 .name   = "gpio-keys",
1015                 .pm     = &gpio_keys_pm_ops,
1016                 .of_match_table = gpio_keys_of_match,
1017                 .dev_groups     = gpio_keys_groups,
1018         }
1019 };
1020
1021 static int __init gpio_keys_init(void)
1022 {
1023         return platform_driver_register(&gpio_keys_device_driver);
1024 }
1025
1026 static void __exit gpio_keys_exit(void)
1027 {
1028         platform_driver_unregister(&gpio_keys_device_driver);
1029 }
1030
1031 late_initcall(gpio_keys_init);
1032 module_exit(gpio_keys_exit);
1033
1034 MODULE_LICENSE("GPL");
1035 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1036 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1037 MODULE_ALIAS("platform:gpio-keys");