package/kernel/gpio-button-hotplug/src/gpio-button-hotplug.c

   1 /*
   2  *  GPIO Button Hotplug driver
   3  *
   4  *  Copyright (C) 2012 Felix Fietkau <nbd@nbd.name>
   5  *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
   6  *
   7  *  Based on the diag.c - GPIO interface driver for Broadcom boards
   8  *    Copyright (C) 2006 Mike Baker <mbm@openwrt.org>,
   9  *    Copyright (C) 2006-2007 Felix Fietkau <nbd@nbd.name>
  10  *    Copyright (C) 2008 Andy Boyett <agb@openwrt.org>
  11  *
  12  *  This program is free software; you can redistribute it and/or modify it
  13  *  under the terms of the GNU General Public License version 2 as published
  14  *  by the Free Software Foundation.
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/version.h>
  19 #include <linux/kmod.h>
  20
  21 #include <linux/workqueue.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/netlink.h>
  24 #include <linux/kobject.h>
  25 #include <linux/input.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/of_gpio.h>
  29 #include <linux/of_irq.h>
  30 #include <linux/gpio_keys.h>
  31 #include <linux/gpio/consumer.h>
  32
  33 #define BH_SKB_SIZE     2048
  34
  35 #define DRV_NAME        "gpio-keys"
  36 #define PFX     DRV_NAME ": "
  37
  38 struct bh_priv {
  39         unsigned long           seen;
  40 };
  41
  42 struct bh_event {
  43         const char              *name;
  44         unsigned int            type;
  45         char                    *action;
  46         unsigned long           seen;
  47
  48         struct sk_buff          *skb;
  49         struct work_struct      work;
  50 };
  51
  52 struct bh_map {
  53         unsigned int    code;
  54         const char      *name;
  55 };
  56
  57 struct gpio_keys_button_data {
  58         struct delayed_work work;
  59         struct bh_priv bh;
  60         int last_state;
  61         int count;
  62         int threshold;
  63         int can_sleep;
  64         int irq;
  65         unsigned int software_debounce;
  66         struct gpio_desc *gpiod;
  67         const struct gpio_keys_button *b;
  68 };
  69
  70 extern u64 uevent_next_seqnum(void);
  71
  72 #define BH_MAP(_code, _name)            \
  73         {                               \
  74                 .code = (_code),        \
  75                 .name = (_name),        \
  76         }
  77
  78 static struct bh_map button_map[] = {
  79         BH_MAP(BTN_0,                   "BTN_0"),
  80         BH_MAP(BTN_1,                   "BTN_1"),
  81         BH_MAP(BTN_2,                   "BTN_2"),
  82         BH_MAP(BTN_3,                   "BTN_3"),
  83         BH_MAP(BTN_4,                   "BTN_4"),
  84         BH_MAP(BTN_5,                   "BTN_5"),
  85         BH_MAP(BTN_6,                   "BTN_6"),
  86         BH_MAP(BTN_7,                   "BTN_7"),
  87         BH_MAP(BTN_8,                   "BTN_8"),
  88         BH_MAP(BTN_9,                   "BTN_9"),
  89         BH_MAP(KEY_BRIGHTNESS_ZERO,     "brightness_zero"),
  90         BH_MAP(KEY_CONFIG,              "config"),
  91         BH_MAP(KEY_COPY,                "copy"),
  92         BH_MAP(KEY_EJECTCD,             "eject"),
  93         BH_MAP(KEY_HELP,                "help"),
  94         BH_MAP(KEY_LIGHTS_TOGGLE,       "lights_toggle"),
  95         BH_MAP(KEY_PHONE,               "phone"),
  96         BH_MAP(KEY_POWER,               "power"),
  97         BH_MAP(KEY_POWER2,              "reboot"),
  98         BH_MAP(KEY_RESTART,             "reset"),
  99         BH_MAP(KEY_RFKILL,              "rfkill"),
 100         BH_MAP(KEY_VIDEO,               "video"),
 101         BH_MAP(KEY_WIMAX,               "wwan"),
 102         BH_MAP(KEY_WLAN,                "wlan"),
 103         BH_MAP(KEY_WPS_BUTTON,          "wps"),
 104 };
 105
 106 /* -------------------------------------------------------------------------*/
 107
 108 static __printf(3, 4)
 109 int bh_event_add_var(struct bh_event *event, int argv, const char *format, ...)
 110 {
 111         static char buf[128];
 112         char *s;
 113         va_list args;
 114         int len;
 115
 116         if (argv)
 117                 return 0;
 118
 119         va_start(args, format);
 120         len = vsnprintf(buf, sizeof(buf), format, args);
 121         va_end(args);
 122
 123         if (len >= sizeof(buf)) {
 124                 WARN(1, "buffer size too small");
 125                 return -ENOMEM;
 126         }
 127
 128         s = skb_put(event->skb, len + 1);
 129         strcpy(s, buf);
 130
 131         pr_debug(PFX "added variable '%s'\n", s);
 132
 133         return 0;
 134 }
 135
 136 static int button_hotplug_fill_event(struct bh_event *event)
 137 {
 138         int ret;
 139
 140         ret = bh_event_add_var(event, 0, "HOME=%s", "/");
 141         if (ret)
 142                 return ret;
 143
 144         ret = bh_event_add_var(event, 0, "PATH=%s",
 145                                         "/sbin:/bin:/usr/sbin:/usr/bin");
 146         if (ret)
 147                 return ret;
 148
 149         ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
 150         if (ret)
 151                 return ret;
 152
 153         ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
 154         if (ret)
 155                 return ret;
 156
 157         ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
 158         if (ret)
 159                 return ret;
 160
 161         if (event->type == EV_SW) {
 162                 ret = bh_event_add_var(event, 0, "TYPE=%s", "switch");
 163                 if (ret)
 164                         return ret;
 165         }
 166
 167         ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
 168         if (ret)
 169                 return ret;
 170
 171         ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
 172
 173         return ret;
 174 }
 175
 176 static void button_hotplug_work(struct work_struct *work)
 177 {
 178         struct bh_event *event = container_of(work, struct bh_event, work);
 179         int ret = 0;
 180
 181         event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
 182         if (!event->skb)
 183                 goto out_free_event;
 184
 185         ret = bh_event_add_var(event, 0, "%s@", event->action);
 186         if (ret)
 187                 goto out_free_skb;
 188
 189         ret = button_hotplug_fill_event(event);
 190         if (ret)
 191                 goto out_free_skb;
 192
 193         NETLINK_CB(event->skb).dst_group = 1;
 194         broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
 195
 196  out_free_skb:
 197         if (ret) {
 198                 pr_err(PFX "work error %d\n", ret);
 199                 kfree_skb(event->skb);
 200         }
 201  out_free_event:
 202         kfree(event);
 203 }
 204
 205 static int button_hotplug_create_event(const char *name, unsigned int type,
 206                 unsigned long seen, int pressed)
 207 {
 208         struct bh_event *event;
 209
 210         pr_debug(PFX "create event, name=%s, seen=%lu, pressed=%d\n",
 211                  name, seen, pressed);
 212
 213         event = kzalloc(sizeof(*event), GFP_KERNEL);
 214         if (!event)
 215                 return -ENOMEM;
 216
 217         event->name = name;
 218         event->type = type;
 219         event->seen = seen;
 220         event->action = pressed ? "pressed" : "released";
 221
 222         INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
 223         schedule_work(&event->work);
 224
 225         return 0;
 226 }
 227
 228 /* -------------------------------------------------------------------------*/
 229
 230 static int button_get_index(unsigned int code)
 231 {
 232         int i;
 233
 234         for (i = 0; i < ARRAY_SIZE(button_map); i++)
 235                 if (button_map[i].code == code)
 236                         return i;
 237
 238         return -1;
 239 }
 240
 241 static void button_hotplug_event(struct gpio_keys_button_data *data,
 242                            unsigned int type, int value)
 243 {
 244         struct bh_priv *priv = &data->bh;
 245         unsigned long seen = jiffies;
 246         int btn;
 247
 248         pr_debug(PFX "event type=%u, code=%u, value=%d\n", type, data->b->code, value);
 249
 250         if ((type != EV_KEY) && (type != EV_SW))
 251                 return;
 252
 253         btn = button_get_index(data->b->code);
 254         if (btn < 0)
 255                 return;
 256
 257         if (priv->seen == 0)
 258                 priv->seen = seen;
 259
 260         button_hotplug_create_event(button_map[btn].name, type,
 261                         (seen - priv->seen) / HZ, value);
 262         priv->seen = seen;
 263 }
 264
 265 struct gpio_keys_button_dev {
 266         int polled;
 267         struct delayed_work work;
 268
 269         struct device *dev;
 270         struct gpio_keys_platform_data *pdata;
 271         struct gpio_keys_button_data data[0];
 272 };
 273
 274 static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
 275 {
 276         int val;
 277
 278         if (bdata->can_sleep)
 279                 val = !!gpio_get_value_cansleep(bdata->b->gpio);
 280         else
 281                 val = !!gpio_get_value(bdata->b->gpio);
 282
 283         return val ^ bdata->b->active_low;
 284 }
 285
 286 static void gpio_keys_polled_check_state(struct gpio_keys_button_data *bdata)
 287 {
 288         int state = gpio_button_get_value(bdata);
 289
 290         if (state != bdata->last_state) {
 291                 unsigned int type = bdata->b->type ?: EV_KEY;
 292
 293                 if (bdata->count < bdata->threshold) {
 294                         bdata->count++;
 295                         return;
 296                 }
 297
 298                 if (bdata->last_state != -1 || type == EV_SW)
 299                         button_hotplug_event(bdata, type, state);
 300
 301                 bdata->last_state = state;
 302         }
 303
 304         bdata->count = 0;
 305 }
 306
 307 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
 308 {
 309         struct gpio_keys_platform_data *pdata = bdev->pdata;
 310         unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
 311
 312         if (delay >= HZ)
 313                 delay = round_jiffies_relative(delay);
 314         schedule_delayed_work(&bdev->work, delay);
 315 }
 316
 317 static void gpio_keys_polled_poll(struct work_struct *work)
 318 {
 319         struct gpio_keys_button_dev *bdev =
 320                 container_of(work, struct gpio_keys_button_dev, work.work);
 321         int i;
 322
 323         for (i = 0; i < bdev->pdata->nbuttons; i++) {
 324                 struct gpio_keys_button_data *bdata = &bdev->data[i];
 325                 gpio_keys_polled_check_state(bdata);
 326         }
 327         gpio_keys_polled_queue_work(bdev);
 328 }
 329
 330 static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev)
 331 {
 332         struct gpio_keys_platform_data *pdata = bdev->pdata;
 333
 334         cancel_delayed_work_sync(&bdev->work);
 335
 336         if (pdata->disable)
 337                 pdata->disable(bdev->dev);
 338 }
 339
 340 static void gpio_keys_irq_work_func(struct work_struct *work)
 341 {
 342         struct gpio_keys_button_data *bdata = container_of(work,
 343                 struct gpio_keys_button_data, work.work);
 344
 345         button_hotplug_event(bdata, bdata->b->type ?: EV_KEY,
 346                              gpio_button_get_value(bdata));
 347 }
 348
 349 static irqreturn_t button_handle_irq(int irq, void *_bdata)
 350 {
 351         struct gpio_keys_button_data *bdata =
 352                 (struct gpio_keys_button_data *) _bdata;
 353
 354         schedule_delayed_work(&bdata->work,
 355                               msecs_to_jiffies(bdata->software_debounce));
 356
 357         return IRQ_HANDLED;
 358 }
 359
 360 #ifdef CONFIG_OF
 361 static struct gpio_keys_platform_data *
 362 gpio_keys_get_devtree_pdata(struct device *dev)
 363 {
 364         struct device_node *node, *pp;
 365         struct gpio_keys_platform_data *pdata;
 366         struct gpio_keys_button *button;
 367         int error;
 368         int nbuttons;
 369         int i = 0;
 370
 371         node = dev->of_node;
 372         if (!node)
 373                 return NULL;
 374
 375         nbuttons = of_get_child_count(node);
 376         if (nbuttons == 0)
 377                 return NULL;
 378
 379         pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * (sizeof *button),
 380                 GFP_KERNEL);
 381         if (!pdata) {
 382                 error = -ENOMEM;
 383                 goto err_out;
 384         }
 385
 386         pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
 387         pdata->nbuttons = nbuttons;
 388
 389         pdata->rep = !!of_get_property(node, "autorepeat", NULL);
 390         of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
 391
 392         for_each_child_of_node(node, pp) {
 393                 enum of_gpio_flags flags;
 394
 395                 if (!of_find_property(pp, "gpios", NULL)) {
 396                         pdata->nbuttons--;
 397                         dev_warn(dev, "Found button without gpios\n");
 398                         continue;
 399                 }
 400
 401                 button = (struct gpio_keys_button *)(&pdata->buttons[i++]);
 402
 403                 button->irq = irq_of_parse_and_map(pp, 0);
 404
 405                 button->gpio = of_get_gpio_flags(pp, 0, &flags);
 406                 if (button->gpio < 0) {
 407                         error = button->gpio;
 408                         if (error != -ENOENT) {
 409                                 if (error != -EPROBE_DEFER)
 410                                         dev_err(dev,
 411                                                 "Failed to get gpio flags, error: %d\n",
 412                                                 error);
 413                                 return ERR_PTR(error);
 414                         }
 415                 } else {
 416                         button->active_low = flags & OF_GPIO_ACTIVE_LOW;
 417                 }
 418
 419                 if (of_property_read_u32(pp, "linux,code", &button->code)) {
 420                         dev_err(dev, "Button without keycode: 0x%x\n",
 421                                 button->gpio);
 422                         error = -EINVAL;
 423                         goto err_out;
 424                 }
 425
 426                 button->desc = of_get_property(pp, "label", NULL);
 427
 428                 if (of_property_read_u32(pp, "linux,input-type", &button->type))
 429                         button->type = EV_KEY;
 430
 431                 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
 432
 433                 if (of_property_read_u32(pp, "debounce-interval",
 434                                         &button->debounce_interval))
 435                         button->debounce_interval = 5;
 436         }
 437
 438         if (pdata->nbuttons == 0) {
 439                 error = -EINVAL;
 440                 goto err_out;
 441         }
 442
 443         return pdata;
 444
 445 err_out:
 446         return ERR_PTR(error);
 447 }
 448
 449 static struct of_device_id gpio_keys_of_match[] = {
 450         { .compatible = "gpio-keys", },
 451         { },
 452 };
 453 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 454
 455 static struct of_device_id gpio_keys_polled_of_match[] = {
 456         { .compatible = "gpio-keys-polled", },
 457         { },
 458 };
 459 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
 460
 461 #else
 462
 463 static inline struct gpio_keys_platform_data *
 464 gpio_keys_get_devtree_pdata(struct device *dev)
 465 {
 466         return NULL;
 467 }
 468 #endif
 469
 470 static int gpio_keys_button_probe(struct platform_device *pdev,
 471                 struct gpio_keys_button_dev **_bdev, int polled)
 472 {
 473         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 474         struct device *dev = &pdev->dev;
 475         struct gpio_keys_button_dev *bdev;
 476         struct gpio_keys_button *buttons;
 477         int error;
 478         int i;
 479
 480         if (!pdata) {
 481                 pdata = gpio_keys_get_devtree_pdata(dev);
 482                 if (IS_ERR(pdata))
 483                         return PTR_ERR(pdata);
 484                 if (!pdata) {
 485                         dev_err(dev, "missing platform data\n");
 486                         return -EINVAL;
 487                 }
 488         }
 489
 490         if (polled && !pdata->poll_interval) {
 491                 dev_err(dev, "missing poll_interval value\n");
 492                 return -EINVAL;
 493         }
 494
 495         buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button),
 496                        GFP_KERNEL);
 497         if (!buttons) {
 498                 dev_err(dev, "no memory for button data\n");
 499                 return -ENOMEM;
 500         }
 501         memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button));
 502
 503         bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) +
 504                        pdata->nbuttons * sizeof(struct gpio_keys_button_data),
 505                        GFP_KERNEL);
 506         if (!bdev) {
 507                 dev_err(dev, "no memory for private data\n");
 508                 return -ENOMEM;
 509         }
 510
 511         bdev->polled = polled;
 512
 513         for (i = 0; i < pdata->nbuttons; i++) {
 514                 struct gpio_keys_button *button = &buttons[i];
 515                 struct gpio_keys_button_data *bdata = &bdev->data[i];
 516                 unsigned int gpio = button->gpio;
 517
 518                 if (button->wakeup) {
 519                         dev_err(dev, DRV_NAME "does not support wakeup\n");
 520                         return -EINVAL;
 521                 }
 522
 523                 error = devm_gpio_request(dev, gpio,
 524                                      button->desc ? button->desc : DRV_NAME);
 525                 if (error) {
 526                         dev_err(dev, "unable to claim gpio %u, err=%d\n",
 527                                 gpio, error);
 528                         return error;
 529                 }
 530                 bdata->gpiod = gpio_to_desc(gpio);
 531                 if (!bdata->gpiod)
 532                         return -EINVAL;
 533
 534                 error = gpio_direction_input(gpio);
 535                 if (error) {
 536                         dev_err(dev,
 537                                 "unable to set direction on gpio %u, err=%d\n",
 538                                 gpio, error);
 539                         return error;
 540                 }
 541
 542                 bdata->can_sleep = gpio_cansleep(gpio);
 543                 bdata->last_state = -1;
 544
 545                 if (bdev->polled) {
 546                         bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
 547                                                         pdata->poll_interval);
 548                 } else {
 549                         bdata->threshold = 1;
 550
 551                         if (button->debounce_interval) {
 552                                 error = gpiod_set_debounce(bdata->gpiod,
 553                                         button->debounce_interval * 1000);
 554                                 /*
 555                                  * use timer if gpiolib doesn't provide
 556                                  * debounce.
 557                                  */
 558                                 if (error < 0) {
 559                                         bdata->software_debounce =
 560                                                 button->debounce_interval;
 561                                 }
 562                         }
 563                 }
 564
 565                 bdata->b = &pdata->buttons[i];
 566         }
 567
 568         bdev->dev = &pdev->dev;
 569         bdev->pdata = pdata;
 570         platform_set_drvdata(pdev, bdev);
 571
 572         *_bdev = bdev;
 573
 574         return 0;
 575 }
 576
 577 static int gpio_keys_probe(struct platform_device *pdev)
 578 {
 579         struct gpio_keys_platform_data *pdata;
 580         struct gpio_keys_button_dev *bdev;
 581         int ret, i;
 582
 583
 584         ret = gpio_keys_button_probe(pdev, &bdev, 0);
 585
 586         if (ret)
 587                 return ret;
 588
 589         pdata = bdev->pdata;
 590         for (i = 0; i < pdata->nbuttons; i++) {
 591                 const struct gpio_keys_button *button = &pdata->buttons[i];
 592                 struct gpio_keys_button_data *bdata = &bdev->data[i];
 593                 unsigned long irqflags = IRQF_ONESHOT;
 594
 595                 if (!button->irq) {
 596                         bdata->irq = gpio_to_irq(button->gpio);
 597
 598                         if (bdata->irq < 0) {
 599                                 dev_err(&pdev->dev, "failed to get irq for gpio:%d\n",
 600                                         button->gpio);
 601                                 continue;
 602                         }
 603
 604                         irqflags |= IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 605                 } else {
 606                         bdata->irq = button->irq;
 607                 }
 608
 609                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_irq_work_func);
 610
 611                 ret = devm_request_threaded_irq(&pdev->dev,
 612                         bdata->irq, NULL, button_handle_irq,
 613                         irqflags, dev_name(&pdev->dev), bdata);
 614
 615                 if (ret < 0) {
 616                         bdata->irq = 0;
 617                         dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n",
 618                                 bdata->irq, button->gpio);
 619                         continue;
 620                 } else {
 621                         dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n",
 622                                 button->gpio, bdata->irq);
 623                 }
 624
 625                 if (bdata->b->type == EV_SW)
 626                         button_hotplug_event(bdata, EV_SW, gpio_button_get_value(bdata));
 627         }
 628
 629         return 0;
 630 }
 631
 632 static int gpio_keys_polled_probe(struct platform_device *pdev)
 633 {
 634         struct gpio_keys_platform_data *pdata;
 635         struct gpio_keys_button_dev *bdev;
 636         int ret;
 637         int i;
 638
 639         ret = gpio_keys_button_probe(pdev, &bdev, 1);
 640
 641         if (ret)
 642                 return ret;
 643
 644         INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
 645
 646         pdata = bdev->pdata;
 647
 648         if (pdata->enable)
 649                 pdata->enable(bdev->dev);
 650
 651         for (i = 0; i < pdata->nbuttons; i++)
 652                 gpio_keys_polled_check_state(&bdev->data[i]);
 653
 654         gpio_keys_polled_queue_work(bdev);
 655
 656         return ret;
 657 }
 658
 659 static void gpio_keys_irq_close(struct gpio_keys_button_dev *bdev)
 660 {
 661         struct gpio_keys_platform_data *pdata = bdev->pdata;
 662         size_t i;
 663
 664         for (i = 0; i < pdata->nbuttons; i++) {
 665                 struct gpio_keys_button_data *bdata = &bdev->data[i];
 666
 667                 disable_irq(bdata->irq);
 668                 cancel_delayed_work_sync(&bdata->work);
 669         }
 670 }
 671
 672 static int gpio_keys_remove(struct platform_device *pdev)
 673 {
 674         struct gpio_keys_button_dev *bdev = platform_get_drvdata(pdev);
 675
 676         platform_set_drvdata(pdev, NULL);
 677
 678         if (bdev->polled)
 679                 gpio_keys_polled_close(bdev);
 680         else
 681                 gpio_keys_irq_close(bdev);
 682
 683         return 0;
 684 }
 685
 686 static struct platform_driver gpio_keys_driver = {
 687         .probe  = gpio_keys_probe,
 688         .remove = gpio_keys_remove,
 689         .driver = {
 690                 .name   = "gpio-keys",
 691                 .owner  = THIS_MODULE,
 692                 .of_match_table = of_match_ptr(gpio_keys_of_match),
 693         },
 694 };
 695
 696 static struct platform_driver gpio_keys_polled_driver = {
 697         .probe  = gpio_keys_polled_probe,
 698         .remove = gpio_keys_remove,
 699         .driver = {
 700                 .name   = "gpio-keys-polled",
 701                 .owner  = THIS_MODULE,
 702                 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
 703         },
 704 };
 705
 706 static int __init gpio_button_init(void)
 707 {
 708         int ret;
 709
 710         ret = platform_driver_register(&gpio_keys_driver);
 711         if (ret)
 712                 return ret;
 713
 714         ret = platform_driver_register(&gpio_keys_polled_driver);
 715         if (ret)
 716                 platform_driver_unregister(&gpio_keys_driver);
 717
 718         return ret;
 719 }
 720
 721 static void __exit gpio_button_exit(void)
 722 {
 723         platform_driver_unregister(&gpio_keys_driver);
 724         platform_driver_unregister(&gpio_keys_polled_driver);
 725 }
 726
 727 module_init(gpio_button_init);
 728 module_exit(gpio_button_exit);
 729
 730 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
 731 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
 732 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
 733 MODULE_LICENSE("GPL v2");
 734 MODULE_ALIAS("platform:" DRV_NAME);