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  * @dev: 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                 default:
 578                         /*
 579                          * For other cases, we are OK letting suspend/resume
 580                          * not reconfigure the trigger type.
 581                          */
 582                         break;
 583                 }
 584         } else {
 585                 if (!button->irq) {
 586                         dev_err(dev, "Found button without gpio or irq\n");
 587                         return -EINVAL;
 588                 }
 589
 590                 bdata->irq = button->irq;
 591
 592                 if (button->type && button->type != EV_KEY) {
 593                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
 594                         return -EINVAL;
 595                 }
 596
 597                 bdata->release_delay = button->debounce_interval;
 598                 timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
 599
 600                 isr = gpio_keys_irq_isr;
 601                 irqflags = 0;
 602
 603                 /*
 604                  * For IRQ buttons, there is no interrupt for release.
 605                  * So we don't need to reconfigure the trigger type for wakeup.
 606                  */
 607         }
 608
 609         bdata->code = &ddata->keymap[idx];
 610         *bdata->code = button->code;
 611         input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
 612
 613         /*
 614          * Install custom action to cancel release timer and
 615          * workqueue item.
 616          */
 617         error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
 618         if (error) {
 619                 dev_err(dev, "failed to register quiesce action, error: %d\n",
 620                         error);
 621                 return error;
 622         }
 623
 624         /*
 625          * If platform has specified that the button can be disabled,
 626          * we don't want it to share the interrupt line.
 627          */
 628         if (!button->can_disable)
 629                 irqflags |= IRQF_SHARED;
 630
 631         error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
 632                                              desc, bdata);
 633         if (error < 0) {
 634                 dev_err(dev, "Unable to claim irq %d; error %d\n",
 635                         bdata->irq, error);
 636                 return error;
 637         }
 638
 639         return 0;
 640 }
 641
 642 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
 643 {
 644         struct input_dev *input = ddata->input;
 645         int i;
 646
 647         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 648                 struct gpio_button_data *bdata = &ddata->data[i];
 649                 if (bdata->gpiod)
 650                         gpio_keys_gpio_report_event(bdata);
 651         }
 652         input_sync(input);
 653 }
 654
 655 static int gpio_keys_open(struct input_dev *input)
 656 {
 657         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 658         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 659         int error;
 660
 661         if (pdata->enable) {
 662                 error = pdata->enable(input->dev.parent);
 663                 if (error)
 664                         return error;
 665         }
 666
 667         /* Report current state of buttons that are connected to GPIOs */
 668         gpio_keys_report_state(ddata);
 669
 670         return 0;
 671 }
 672
 673 static void gpio_keys_close(struct input_dev *input)
 674 {
 675         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
 676         const struct gpio_keys_platform_data *pdata = ddata->pdata;
 677
 678         if (pdata->disable)
 679                 pdata->disable(input->dev.parent);
 680 }
 681
 682 /*
 683  * Handlers for alternative sources of platform_data
 684  */
 685
 686 /*
 687  * Translate properties into platform_data
 688  */
 689 static struct gpio_keys_platform_data *
 690 gpio_keys_get_devtree_pdata(struct device *dev)
 691 {
 692         struct gpio_keys_platform_data *pdata;
 693         struct gpio_keys_button *button;
 694         struct fwnode_handle *child;
 695         int nbuttons;
 696
 697         nbuttons = device_get_child_node_count(dev);
 698         if (nbuttons == 0)
 699                 return ERR_PTR(-ENODEV);
 700
 701         pdata = devm_kzalloc(dev,
 702                              sizeof(*pdata) + nbuttons * sizeof(*button),
 703                              GFP_KERNEL);
 704         if (!pdata)
 705                 return ERR_PTR(-ENOMEM);
 706
 707         button = (struct gpio_keys_button *)(pdata + 1);
 708
 709         pdata->buttons = button;
 710         pdata->nbuttons = nbuttons;
 711
 712         pdata->rep = device_property_read_bool(dev, "autorepeat");
 713
 714         device_property_read_string(dev, "label", &pdata->name);
 715
 716         device_for_each_child_node(dev, child) {
 717                 if (is_of_node(child))
 718                         button->irq =
 719                                 irq_of_parse_and_map(to_of_node(child), 0);
 720
 721                 if (fwnode_property_read_u32(child, "linux,code",
 722                                              &button->code)) {
 723                         dev_err(dev, "Button without keycode\n");
 724                         fwnode_handle_put(child);
 725                         return ERR_PTR(-EINVAL);
 726                 }
 727
 728                 fwnode_property_read_string(child, "label", &button->desc);
 729
 730                 if (fwnode_property_read_u32(child, "linux,input-type",
 731                                              &button->type))
 732                         button->type = EV_KEY;
 733
 734                 button->wakeup =
 735                         fwnode_property_read_bool(child, "wakeup-source") ||
 736                         /* legacy name */
 737                         fwnode_property_read_bool(child, "gpio-key,wakeup");
 738
 739                 fwnode_property_read_u32(child, "wakeup-event-action",
 740                                          &button->wakeup_event_action);
 741
 742                 button->can_disable =
 743                         fwnode_property_read_bool(child, "linux,can-disable");
 744
 745                 if (fwnode_property_read_u32(child, "debounce-interval",
 746                                          &button->debounce_interval))
 747                         button->debounce_interval = 5;
 748
 749                 button++;
 750         }
 751
 752         return pdata;
 753 }
 754
 755 static const struct of_device_id gpio_keys_of_match[] = {
 756         { .compatible = "gpio-keys", },
 757         { },
 758 };
 759 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 760
 761 static int gpio_keys_probe(struct platform_device *pdev)
 762 {
 763         struct device *dev = &pdev->dev;
 764         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
 765         struct fwnode_handle *child = NULL;
 766         struct gpio_keys_drvdata *ddata;
 767         struct input_dev *input;
 768         int i, error;
 769         int wakeup = 0;
 770
 771         if (!pdata) {
 772                 pdata = gpio_keys_get_devtree_pdata(dev);
 773                 if (IS_ERR(pdata))
 774                         return PTR_ERR(pdata);
 775         }
 776
 777         ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
 778                              GFP_KERNEL);
 779         if (!ddata) {
 780                 dev_err(dev, "failed to allocate state\n");
 781                 return -ENOMEM;
 782         }
 783
 784         ddata->keymap = devm_kcalloc(dev,
 785                                      pdata->nbuttons, sizeof(ddata->keymap[0]),
 786                                      GFP_KERNEL);
 787         if (!ddata->keymap)
 788                 return -ENOMEM;
 789
 790         input = devm_input_allocate_device(dev);
 791         if (!input) {
 792                 dev_err(dev, "failed to allocate input device\n");
 793                 return -ENOMEM;
 794         }
 795
 796         ddata->pdata = pdata;
 797         ddata->input = input;
 798         mutex_init(&ddata->disable_lock);
 799
 800         platform_set_drvdata(pdev, ddata);
 801         input_set_drvdata(input, ddata);
 802
 803         input->name = pdata->name ? : pdev->name;
 804         input->phys = "gpio-keys/input0";
 805         input->dev.parent = dev;
 806         input->open = gpio_keys_open;
 807         input->close = gpio_keys_close;
 808
 809         input->id.bustype = BUS_HOST;
 810         input->id.vendor = 0x0001;
 811         input->id.product = 0x0001;
 812         input->id.version = 0x0100;
 813
 814         input->keycode = ddata->keymap;
 815         input->keycodesize = sizeof(ddata->keymap[0]);
 816         input->keycodemax = pdata->nbuttons;
 817
 818         /* Enable auto repeat feature of Linux input subsystem */
 819         if (pdata->rep)
 820                 __set_bit(EV_REP, input->evbit);
 821
 822         for (i = 0; i < pdata->nbuttons; i++) {
 823                 const struct gpio_keys_button *button = &pdata->buttons[i];
 824
 825                 if (!dev_get_platdata(dev)) {
 826                         child = device_get_next_child_node(dev, child);
 827                         if (!child) {
 828                                 dev_err(dev,
 829                                         "missing child device node for entry %d\n",
 830                                         i);
 831                                 return -EINVAL;
 832                         }
 833                 }
 834
 835                 error = gpio_keys_setup_key(pdev, input, ddata,
 836                                             button, i, child);
 837                 if (error) {
 838                         fwnode_handle_put(child);
 839                         return error;
 840                 }
 841
 842                 if (button->wakeup)
 843                         wakeup = 1;
 844         }
 845
 846         fwnode_handle_put(child);
 847
 848         error = input_register_device(input);
 849         if (error) {
 850                 dev_err(dev, "Unable to register input device, error: %d\n",
 851                         error);
 852                 return error;
 853         }
 854
 855         device_init_wakeup(dev, wakeup);
 856
 857         return 0;
 858 }
 859
 860 static int __maybe_unused
 861 gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
 862 {
 863         int error;
 864
 865         error = enable_irq_wake(bdata->irq);
 866         if (error) {
 867                 dev_err(bdata->input->dev.parent,
 868                         "failed to configure IRQ %d as wakeup source: %d\n",
 869                         bdata->irq, error);
 870                 return error;
 871         }
 872
 873         if (bdata->wakeup_trigger_type) {
 874                 error = irq_set_irq_type(bdata->irq,
 875                                          bdata->wakeup_trigger_type);
 876                 if (error) {
 877                         dev_err(bdata->input->dev.parent,
 878                                 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
 879                                 bdata->wakeup_trigger_type, bdata->irq, error);
 880                         disable_irq_wake(bdata->irq);
 881                         return error;
 882                 }
 883         }
 884
 885         return 0;
 886 }
 887
 888 static void __maybe_unused
 889 gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
 890 {
 891         int error;
 892
 893         /*
 894          * The trigger type is always both edges for gpio-based keys and we do
 895          * not support changing wakeup trigger for interrupt-based keys.
 896          */
 897         if (bdata->wakeup_trigger_type) {
 898                 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
 899                 if (error)
 900                         dev_warn(bdata->input->dev.parent,
 901                                  "failed to restore interrupt trigger for IRQ %d: %d\n",
 902                                  bdata->irq, error);
 903         }
 904
 905         error = disable_irq_wake(bdata->irq);
 906         if (error)
 907                 dev_warn(bdata->input->dev.parent,
 908                          "failed to disable IRQ %d as wake source: %d\n",
 909                          bdata->irq, error);
 910 }
 911
 912 static int __maybe_unused
 913 gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
 914 {
 915         struct gpio_button_data *bdata;
 916         int error;
 917         int i;
 918
 919         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 920                 bdata = &ddata->data[i];
 921                 if (bdata->button->wakeup) {
 922                         error = gpio_keys_button_enable_wakeup(bdata);
 923                         if (error)
 924                                 goto err_out;
 925                 }
 926                 bdata->suspended = true;
 927         }
 928
 929         return 0;
 930
 931 err_out:
 932         while (i--) {
 933                 bdata = &ddata->data[i];
 934                 if (bdata->button->wakeup)
 935                         gpio_keys_button_disable_wakeup(bdata);
 936                 bdata->suspended = false;
 937         }
 938
 939         return error;
 940 }
 941
 942 static void __maybe_unused
 943 gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
 944 {
 945         struct gpio_button_data *bdata;
 946         int i;
 947
 948         for (i = 0; i < ddata->pdata->nbuttons; i++) {
 949                 bdata = &ddata->data[i];
 950                 bdata->suspended = false;
 951                 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
 952                         gpio_keys_button_disable_wakeup(bdata);
 953         }
 954 }
 955
 956 static int __maybe_unused gpio_keys_suspend(struct device *dev)
 957 {
 958         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 959         struct input_dev *input = ddata->input;
 960         int error;
 961
 962         if (device_may_wakeup(dev)) {
 963                 error = gpio_keys_enable_wakeup(ddata);
 964                 if (error)
 965                         return error;
 966         } else {
 967                 mutex_lock(&input->mutex);
 968                 if (input_device_enabled(input))
 969                         gpio_keys_close(input);
 970                 mutex_unlock(&input->mutex);
 971         }
 972
 973         return 0;
 974 }
 975
 976 static int __maybe_unused gpio_keys_resume(struct device *dev)
 977 {
 978         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 979         struct input_dev *input = ddata->input;
 980         int error = 0;
 981
 982         if (device_may_wakeup(dev)) {
 983                 gpio_keys_disable_wakeup(ddata);
 984         } else {
 985                 mutex_lock(&input->mutex);
 986                 if (input_device_enabled(input))
 987                         error = gpio_keys_open(input);
 988                 mutex_unlock(&input->mutex);
 989         }
 990
 991         if (error)
 992                 return error;
 993
 994         gpio_keys_report_state(ddata);
 995         return 0;
 996 }
 997
 998 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
 999
1000 static void gpio_keys_shutdown(struct platform_device *pdev)
1001 {
1002         int ret;
1003
1004         ret = gpio_keys_suspend(&pdev->dev);
1005         if (ret)
1006                 dev_err(&pdev->dev, "failed to shutdown\n");
1007 }
1008
1009 static struct platform_driver gpio_keys_device_driver = {
1010         .probe          = gpio_keys_probe,
1011         .shutdown       = gpio_keys_shutdown,
1012         .driver         = {
1013                 .name   = "gpio-keys",
1014                 .pm     = &gpio_keys_pm_ops,
1015                 .of_match_table = gpio_keys_of_match,
1016                 .dev_groups     = gpio_keys_groups,
1017         }
1018 };
1019
1020 static int __init gpio_keys_init(void)
1021 {
1022         return platform_driver_register(&gpio_keys_device_driver);
1023 }
1024
1025 static void __exit gpio_keys_exit(void)
1026 {
1027         platform_driver_unregister(&gpio_keys_device_driver);
1028 }
1029
1030 late_initcall(gpio_keys_init);
1031 module_exit(gpio_keys_exit);
1032
1033 MODULE_LICENSE("GPL");
1034 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1035 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1036 MODULE_ALIAS("platform:gpio-keys");