Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4

Linux/drivers/input/keyboard/gpio_keys.c

  1 /*
  2  * Driver for keys on GPIO lines capable of generating interrupts.
  3  *
  4  * Copyright 2005 Phil Blundell
  5  * Copyright 2010, 2011 David Jander <david@protonic.nl>
  6  *
  7  * This program is free software; you can redistribute it and/or modify
  8  * it under the terms of the GNU General Public License version 2 as
  9  * published by the Free Software Foundation.
 10  */
 11 
 12 #include <linux/module.h>
 13 
 14 #include <linux/init.h>
 15 #include <linux/fs.h>
 16 #include <linux/interrupt.h>
 17 #include <linux/irq.h>
 18 #include <linux/sched.h>
 19 #include <linux/pm.h>
 20 #include <linux/slab.h>
 21 #include <linux/sysctl.h>
 22 #include <linux/proc_fs.h>
 23 #include <linux/delay.h>
 24 #include <linux/platform_device.h>
 25 #include <linux/input.h>
 26 #include <linux/gpio_keys.h>
 27 #include <linux/workqueue.h>
 28 #include <linux/gpio.h>
 29 #include <linux/of.h>
 30 #include <linux/of_platform.h>
 31 #include <linux/of_gpio.h>
 32 #include <linux/of_irq.h>
 33 #include <linux/spinlock.h>
 34 
 35 struct gpio_button_data {
 36         const struct gpio_keys_button *button;
 37         struct input_dev *input;
 38 
 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         spinlock_t lock;
 47         bool disabled;
 48         bool key_pressed;
 49 };
 50 
 51 struct gpio_keys_drvdata {
 52         const struct gpio_keys_platform_data *pdata;
 53         struct input_dev *input;
 54         struct mutex disable_lock;
 55         struct gpio_button_data data[0];
 56 };
 57 
 58 /*
 59  * SYSFS interface for enabling/disabling keys and switches:
 60  *
 61  * There are 4 attributes under /sys/devices/platform/gpio-keys/
 62  *      keys [ro]              - bitmap of keys (EV_KEY) which can be
 63  *                               disabled
 64  *      switches [ro]          - bitmap of switches (EV_SW) which can be
 65  *                               disabled
 66  *      disabled_keys [rw]     - bitmap of keys currently disabled
 67  *      disabled_switches [rw] - bitmap of switches currently disabled
 68  *
 69  * Userland can change these values and hence disable event generation
 70  * for each key (or switch). Disabling a key means its interrupt line
 71  * is disabled.
 72  *
 73  * For example, if we have following switches set up as gpio-keys:
 74  *      SW_DOCK = 5
 75  *      SW_CAMERA_LENS_COVER = 9
 76  *      SW_KEYPAD_SLIDE = 10
 77  *      SW_FRONT_PROXIMITY = 11
 78  * This is read from switches:
 79  *      11-9,5
 80  * Next we want to disable proximity (11) and dock (5), we write:
 81  *      11,5
 82  * to file disabled_switches. Now proximity and dock IRQs are disabled.
 83  * This can be verified by reading the file disabled_switches:
 84  *      11,5
 85  * If we now want to enable proximity (11) switch we write:
 86  *      5
 87  * to disabled_switches.
 88  *
 89  * We can disable only those keys which don't allow sharing the irq.
 90  */
 91 
 92 /**
 93  * get_n_events_by_type() - returns maximum number of events per @type
 94  * @type: type of button (%EV_KEY, %EV_SW)
 95  *
 96  * Return value of this function can be used to allocate bitmap
 97  * large enough to hold all bits for given type.
 98  */
 99 static inline int get_n_events_by_type(int type)
100 {
101         BUG_ON(type != EV_SW && type != EV_KEY);
102 
103         return (type == EV_KEY) ? KEY_CNT : SW_CNT;
104 }
105 
106 /**
107  * gpio_keys_disable_button() - disables given GPIO button
108  * @bdata: button data for button to be disabled
109  *
110  * Disables button pointed by @bdata. This is done by masking
111  * IRQ line. After this function is called, button won't generate
112  * input events anymore. Note that one can only disable buttons
113  * that don't share IRQs.
114  *
115  * Make sure that @bdata->disable_lock is locked when entering
116  * this function to avoid races when concurrent threads are
117  * disabling buttons at the same time.
118  */
119 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
120 {
121         if (!bdata->disabled) {
122                 /*
123                  * Disable IRQ and associated timer/work structure.
124                  */
125                 disable_irq(bdata->irq);
126 
127                 if (gpio_is_valid(bdata->button->gpio))
128                         cancel_delayed_work_sync(&bdata->work);
129                 else
130                         del_timer_sync(&bdata->release_timer);
131 
132                 bdata->disabled = true;
133         }
134 }
135 
136 /**
137  * gpio_keys_enable_button() - enables given GPIO button
138  * @bdata: button data for button to be disabled
139  *
140  * Enables given button pointed by @bdata.
141  *
142  * Make sure that @bdata->disable_lock is locked when entering
143  * this function to avoid races with concurrent threads trying
144  * to enable the same button at the same time.
145  */
146 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
147 {
148         if (bdata->disabled) {
149                 enable_irq(bdata->irq);
150                 bdata->disabled = false;
151         }
152 }
153 
154 /**
155  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
156  * @ddata: pointer to drvdata
157  * @buf: buffer where stringified bitmap is written
158  * @type: button type (%EV_KEY, %EV_SW)
159  * @only_disabled: does caller want only those buttons that are
160  *                 currently disabled or all buttons that can be
161  *                 disabled
162  *
163  * This function writes buttons that can be disabled to @buf. If
164  * @only_disabled is true, then @buf contains only those buttons
165  * that are currently disabled. Returns 0 on success or negative
166  * errno on failure.
167  */
168 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
169                                           char *buf, unsigned int type,
170                                           bool only_disabled)
171 {
172         int n_events = get_n_events_by_type(type);
173         unsigned long *bits;
174         ssize_t ret;
175         int i;
176 
177         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
178         if (!bits)
179                 return -ENOMEM;
180 
181         for (i = 0; i < ddata->pdata->nbuttons; i++) {
182                 struct gpio_button_data *bdata = &ddata->data[i];
183 
184                 if (bdata->button->type != type)
185                         continue;
186 
187                 if (only_disabled && !bdata->disabled)
188                         continue;
189 
190                 __set_bit(bdata->button->code, bits);
191         }
192 
193         ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
194         buf[ret++] = '\n';
195         buf[ret] = '\0';
196 
197         kfree(bits);
198 
199         return ret;
200 }
201 
202 /**
203  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
204  * @ddata: pointer to drvdata
205  * @buf: buffer from userspace that contains stringified bitmap
206  * @type: button type (%EV_KEY, %EV_SW)
207  *
208  * This function parses stringified bitmap from @buf and disables/enables
209  * GPIO buttons accordingly. Returns 0 on success and negative error
210  * on failure.
211  */
212 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
213                                            const char *buf, unsigned int type)
214 {
215         int n_events = get_n_events_by_type(type);
216         unsigned long *bits;
217         ssize_t error;
218         int i;
219 
220         bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
221         if (!bits)
222                 return -ENOMEM;
223 
224         error = bitmap_parselist(buf, bits, n_events);
225         if (error)
226                 goto out;
227 
228         /* First validate */
229         for (i = 0; i < ddata->pdata->nbuttons; i++) {
230                 struct gpio_button_data *bdata = &ddata->data[i];
231 
232                 if (bdata->button->type != type)
233                         continue;
234 
235                 if (test_bit(bdata->button->code, bits) &&
236                     !bdata->button->can_disable) {
237                         error = -EINVAL;
238                         goto out;
239                 }
240         }
241 
242         if (i == ddata->pdata->nbuttons) {
243                 error = -EINVAL;
244                 goto out;
245         }
246 
247         mutex_lock(&ddata->disable_lock);
248 
249         for (i = 0; i < ddata->pdata->nbuttons; i++) {
250                 struct gpio_button_data *bdata = &ddata->data[i];
251 
252                 if (bdata->button->type != type)
253                         continue;
254 
255                 if (test_bit(bdata->button->code, bits))
256                         gpio_keys_disable_button(bdata);
257                 else
258                         gpio_keys_enable_button(bdata);
259         }
260 
261         mutex_unlock(&ddata->disable_lock);
262 
263 out:
264         kfree(bits);
265         return error;
266 }
267 
268 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
269 static ssize_t gpio_keys_show_##name(struct device *dev,                \
270                                      struct device_attribute *attr,     \
271                                      char *buf)                         \
272 {                                                                       \
273         struct platform_device *pdev = to_platform_device(dev);         \
274         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
275                                                                         \
276         return gpio_keys_attr_show_helper(ddata, buf,                   \
277                                           type, only_disabled);         \
278 }
279 
280 ATTR_SHOW_FN(keys, EV_KEY, false);
281 ATTR_SHOW_FN(switches, EV_SW, false);
282 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
283 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
284 
285 /*
286  * ATTRIBUTES:
287  *
288  * /sys/devices/platform/gpio-keys/keys [ro]
289  * /sys/devices/platform/gpio-keys/switches [ro]
290  */
291 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
292 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
293 
294 #define ATTR_STORE_FN(name, type)                                       \
295 static ssize_t gpio_keys_store_##name(struct device *dev,               \
296                                       struct device_attribute *attr,    \
297                                       const char *buf,                  \
298                                       size_t count)                     \
299 {                                                                       \
300         struct platform_device *pdev = to_platform_device(dev);         \
301         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
302         ssize_t error;                                                  \
303                                                                         \
304         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
305         if (error)                                                      \
306                 return error;                                           \
307                                                                         \
308         return count;                                                   \
309 }
310 
311 ATTR_STORE_FN(disabled_keys, EV_KEY);
312 ATTR_STORE_FN(disabled_switches, EV_SW);
313 
314 /*
315  * ATTRIBUTES:
316  *
317  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
318  * /sys/devices/platform/gpio-keys/disables_switches [rw]
319  */
320 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
321                    gpio_keys_show_disabled_keys,
322                    gpio_keys_store_disabled_keys);
323 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
324                    gpio_keys_show_disabled_switches,
325                    gpio_keys_store_disabled_switches);
326 
327 static struct attribute *gpio_keys_attrs[] = {
328         &dev_attr_keys.attr,
329         &dev_attr_switches.attr,
330         &dev_attr_disabled_keys.attr,
331         &dev_attr_disabled_switches.attr,
332         NULL,
333 };
334 
335 static struct attribute_group gpio_keys_attr_group = {
336         .attrs = gpio_keys_attrs,
337 };
338 
339 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
340 {
341         const struct gpio_keys_button *button = bdata->button;
342         struct input_dev *input = bdata->input;
343         unsigned int type = button->type ?: EV_KEY;
344         int state = gpio_get_value_cansleep(button->gpio);
345 
346         if (state < 0) {
347                 dev_err(input->dev.parent, "failed to get gpio state\n");
348                 return;
349         }
350 
351         state = (state ? 1 : 0) ^ button->active_low;
352         if (type == EV_ABS) {
353                 if (state)
354                         input_event(input, type, button->code, button->value);
355         } else {
356                 input_event(input, type, button->code, !!state);
357         }
358         input_sync(input);
359 }
360 
361 static void gpio_keys_gpio_work_func(struct work_struct *work)
362 {
363         struct gpio_button_data *bdata =
364                 container_of(work, struct gpio_button_data, work.work);
365 
366         gpio_keys_gpio_report_event(bdata);
367 
368         if (bdata->button->wakeup)
369                 pm_relax(bdata->input->dev.parent);
370 }
371 
372 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
373 {
374         struct gpio_button_data *bdata = dev_id;
375 
376         BUG_ON(irq != bdata->irq);
377 
378         if (bdata->button->wakeup)
379                 pm_stay_awake(bdata->input->dev.parent);
380 
381         mod_delayed_work(system_wq,
382                          &bdata->work,
383                          msecs_to_jiffies(bdata->software_debounce));
384 
385         return IRQ_HANDLED;
386 }
387 
388 static void gpio_keys_irq_timer(unsigned long _data)
389 {
390         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
391         struct input_dev *input = bdata->input;
392         unsigned long flags;
393 
394         spin_lock_irqsave(&bdata->lock, flags);
395         if (bdata->key_pressed) {
396                 input_event(input, EV_KEY, bdata->button->code, 0);
397                 input_sync(input);
398                 bdata->key_pressed = false;
399         }
400         spin_unlock_irqrestore(&bdata->lock, flags);
401 }
402 
403 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
404 {
405         struct gpio_button_data *bdata = dev_id;
406         const struct gpio_keys_button *button = bdata->button;
407         struct input_dev *input = bdata->input;
408         unsigned long flags;
409 
410         BUG_ON(irq != bdata->irq);
411 
412         spin_lock_irqsave(&bdata->lock, flags);
413 
414         if (!bdata->key_pressed) {
415                 if (bdata->button->wakeup)
416                         pm_wakeup_event(bdata->input->dev.parent, 0);
417 
418                 input_event(input, EV_KEY, button->code, 1);
419                 input_sync(input);
420 
421                 if (!bdata->release_delay) {
422                         input_event(input, EV_KEY, button->code, 0);
423                         input_sync(input);
424                         goto out;
425                 }
426 
427                 bdata->key_pressed = true;
428         }
429 
430         if (bdata->release_delay)
431                 mod_timer(&bdata->release_timer,
432                         jiffies + msecs_to_jiffies(bdata->release_delay));
433 out:
434         spin_unlock_irqrestore(&bdata->lock, flags);
435         return IRQ_HANDLED;
436 }
437 
438 static void gpio_keys_quiesce_key(void *data)
439 {
440         struct gpio_button_data *bdata = data;
441 
442         if (gpio_is_valid(bdata->button->gpio))
443                 cancel_delayed_work_sync(&bdata->work);
444         else
445                 del_timer_sync(&bdata->release_timer);
446 }
447 
448 static int gpio_keys_setup_key(struct platform_device *pdev,
449                                 struct input_dev *input,
450                                 struct gpio_button_data *bdata,
451                                 const struct gpio_keys_button *button)
452 {
453         const char *desc = button->desc ? button->desc : "gpio_keys";
454         struct device *dev = &pdev->dev;
455         irq_handler_t isr;
456         unsigned long irqflags;
457         int irq;
458         int error;
459 
460         bdata->input = input;
461         bdata->button = button;
462         spin_lock_init(&bdata->lock);
463 
464         if (gpio_is_valid(button->gpio)) {
465 
466                 error = devm_gpio_request_one(&pdev->dev, button->gpio,
467                                               GPIOF_IN, desc);
468                 if (error < 0) {
469                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
470                                 button->gpio, error);
471                         return error;
472                 }
473 
474                 if (button->debounce_interval) {
475                         error = gpio_set_debounce(button->gpio,
476                                         button->debounce_interval * 1000);
477                         /* use timer if gpiolib doesn't provide debounce */
478                         if (error < 0)
479                                 bdata->software_debounce =
480                                                 button->debounce_interval;
481                 }
482 
483                 if (button->irq) {
484                         bdata->irq = button->irq;
485                 } else {
486                         irq = gpio_to_irq(button->gpio);
487                         if (irq < 0) {
488                                 error = irq;
489                                 dev_err(dev,
490                                         "Unable to get irq number for GPIO %d, error %d\n",
491                                         button->gpio, error);
492                                 return error;
493                         }
494                         bdata->irq = irq;
495                 }
496 
497                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
498 
499                 isr = gpio_keys_gpio_isr;
500                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
501 
502         } else {
503                 if (!button->irq) {
504                         dev_err(dev, "No IRQ specified\n");
505                         return -EINVAL;
506                 }
507                 bdata->irq = button->irq;
508 
509                 if (button->type && button->type != EV_KEY) {
510                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
511                         return -EINVAL;
512                 }
513 
514                 bdata->release_delay = button->debounce_interval;
515                 setup_timer(&bdata->release_timer,
516                             gpio_keys_irq_timer, (unsigned long)bdata);
517 
518                 isr = gpio_keys_irq_isr;
519                 irqflags = 0;
520         }
521 
522         input_set_capability(input, button->type ?: EV_KEY, button->code);
523 
524         /*
525          * Install custom action to cancel release timer and
526          * workqueue item.
527          */
528         error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
529         if (error) {
530                 dev_err(&pdev->dev,
531                         "failed to register quiesce action, error: %d\n",
532                         error);
533                 return error;
534         }
535 
536         /*
537          * If platform has specified that the button can be disabled,
538          * we don't want it to share the interrupt line.
539          */
540         if (!button->can_disable)
541                 irqflags |= IRQF_SHARED;
542 
543         error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
544                                              isr, irqflags, desc, bdata);
545         if (error < 0) {
546                 dev_err(dev, "Unable to claim irq %d; error %d\n",
547                         bdata->irq, error);
548                 return error;
549         }
550 
551         return 0;
552 }
553 
554 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
555 {
556         struct input_dev *input = ddata->input;
557         int i;
558 
559         for (i = 0; i < ddata->pdata->nbuttons; i++) {
560                 struct gpio_button_data *bdata = &ddata->data[i];
561                 if (gpio_is_valid(bdata->button->gpio))
562                         gpio_keys_gpio_report_event(bdata);
563         }
564         input_sync(input);
565 }
566 
567 static int gpio_keys_open(struct input_dev *input)
568 {
569         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
570         const struct gpio_keys_platform_data *pdata = ddata->pdata;
571         int error;
572 
573         if (pdata->enable) {
574                 error = pdata->enable(input->dev.parent);
575                 if (error)
576                         return error;
577         }
578 
579         /* Report current state of buttons that are connected to GPIOs */
580         gpio_keys_report_state(ddata);
581 
582         return 0;
583 }
584 
585 static void gpio_keys_close(struct input_dev *input)
586 {
587         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
588         const struct gpio_keys_platform_data *pdata = ddata->pdata;
589 
590         if (pdata->disable)
591                 pdata->disable(input->dev.parent);
592 }
593 
594 /*
595  * Handlers for alternative sources of platform_data
596  */
597 
598 #ifdef CONFIG_OF
599 /*
600  * Translate OpenFirmware node properties into platform_data
601  */
602 static struct gpio_keys_platform_data *
603 gpio_keys_get_devtree_pdata(struct device *dev)
604 {
605         struct device_node *node, *pp;
606         struct gpio_keys_platform_data *pdata;
607         struct gpio_keys_button *button;
608         int error;
609         int nbuttons;
610         int i;
611 
612         node = dev->of_node;
613         if (!node)
614                 return ERR_PTR(-ENODEV);
615 
616         nbuttons = of_get_child_count(node);
617         if (nbuttons == 0)
618                 return ERR_PTR(-ENODEV);
619 
620         pdata = devm_kzalloc(dev,
621                              sizeof(*pdata) + nbuttons * sizeof(*button),
622                              GFP_KERNEL);
623         if (!pdata)
624                 return ERR_PTR(-ENOMEM);
625 
626         pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
627         pdata->nbuttons = nbuttons;
628 
629         pdata->rep = !!of_get_property(node, "autorepeat", NULL);
630 
631         i = 0;
632         for_each_child_of_node(node, pp) {
633                 enum of_gpio_flags flags;
634 
635                 button = &pdata->buttons[i++];
636 
637                 button->gpio = of_get_gpio_flags(pp, 0, &flags);
638                 if (button->gpio < 0) {
639                         error = button->gpio;
640                         if (error != -ENOENT) {
641                                 if (error != -EPROBE_DEFER)
642                                         dev_err(dev,
643                                                 "Failed to get gpio flags, error: %d\n",
644                                                 error);
645                                 return ERR_PTR(error);
646                         }
647                 } else {
648                         button->active_low = flags & OF_GPIO_ACTIVE_LOW;
649                 }
650 
651                 button->irq = irq_of_parse_and_map(pp, 0);
652 
653                 if (!gpio_is_valid(button->gpio) && !button->irq) {
654                         dev_err(dev, "Found button without gpios or irqs\n");
655                         return ERR_PTR(-EINVAL);
656                 }
657 
658                 if (of_property_read_u32(pp, "linux,code", &button->code)) {
659                         dev_err(dev, "Button without keycode: 0x%x\n",
660                                 button->gpio);
661                         return ERR_PTR(-EINVAL);
662                 }
663 
664                 button->desc = of_get_property(pp, "label", NULL);
665 
666                 if (of_property_read_u32(pp, "linux,input-type", &button->type))
667                         button->type = EV_KEY;
668 
669                 button->wakeup = of_property_read_bool(pp, "wakeup-source") ||
670                                  /* legacy name */
671                                  of_property_read_bool(pp, "gpio-key,wakeup");
672 
673                 button->can_disable = !!of_get_property(pp, "linux,can-disable", NULL);
674 
675                 if (of_property_read_u32(pp, "debounce-interval",
676                                          &button->debounce_interval))
677                         button->debounce_interval = 5;
678         }
679 
680         if (pdata->nbuttons == 0)
681                 return ERR_PTR(-EINVAL);
682 
683         return pdata;
684 }
685 
686 static const struct of_device_id gpio_keys_of_match[] = {
687         { .compatible = "gpio-keys", },
688         { },
689 };
690 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
691 
692 #else
693 
694 static inline struct gpio_keys_platform_data *
695 gpio_keys_get_devtree_pdata(struct device *dev)
696 {
697         return ERR_PTR(-ENODEV);
698 }
699 
700 #endif
701 
702 static int gpio_keys_probe(struct platform_device *pdev)
703 {
704         struct device *dev = &pdev->dev;
705         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
706         struct gpio_keys_drvdata *ddata;
707         struct input_dev *input;
708         size_t size;
709         int i, error;
710         int wakeup = 0;
711 
712         if (!pdata) {
713                 pdata = gpio_keys_get_devtree_pdata(dev);
714                 if (IS_ERR(pdata))
715                         return PTR_ERR(pdata);
716         }
717 
718         size = sizeof(struct gpio_keys_drvdata) +
719                         pdata->nbuttons * sizeof(struct gpio_button_data);
720         ddata = devm_kzalloc(dev, size, GFP_KERNEL);
721         if (!ddata) {
722                 dev_err(dev, "failed to allocate state\n");
723                 return -ENOMEM;
724         }
725 
726         input = devm_input_allocate_device(dev);
727         if (!input) {
728                 dev_err(dev, "failed to allocate input device\n");
729                 return -ENOMEM;
730         }
731 
732         ddata->pdata = pdata;
733         ddata->input = input;
734         mutex_init(&ddata->disable_lock);
735 
736         platform_set_drvdata(pdev, ddata);
737         input_set_drvdata(input, ddata);
738 
739         input->name = pdata->name ? : pdev->name;
740         input->phys = "gpio-keys/input0";
741         input->dev.parent = &pdev->dev;
742         input->open = gpio_keys_open;
743         input->close = gpio_keys_close;
744 
745         input->id.bustype = BUS_HOST;
746         input->id.vendor = 0x0001;
747         input->id.product = 0x0001;
748         input->id.version = 0x0100;
749 
750         /* Enable auto repeat feature of Linux input subsystem */
751         if (pdata->rep)
752                 __set_bit(EV_REP, input->evbit);
753 
754         for (i = 0; i < pdata->nbuttons; i++) {
755                 const struct gpio_keys_button *button = &pdata->buttons[i];
756                 struct gpio_button_data *bdata = &ddata->data[i];
757 
758                 error = gpio_keys_setup_key(pdev, input, bdata, button);
759                 if (error)
760                         return error;
761 
762                 if (button->wakeup)
763                         wakeup = 1;
764         }
765 
766         error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
767         if (error) {
768                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
769                         error);
770                 return error;
771         }
772 
773         error = input_register_device(input);
774         if (error) {
775                 dev_err(dev, "Unable to register input device, error: %d\n",
776                         error);
777                 goto err_remove_group;
778         }
779 
780         device_init_wakeup(&pdev->dev, wakeup);
781 
782         return 0;
783 
784 err_remove_group:
785         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
786         return error;
787 }
788 
789 static int gpio_keys_remove(struct platform_device *pdev)
790 {
791         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
792 
793         device_init_wakeup(&pdev->dev, 0);
794 
795         return 0;
796 }
797 
798 #ifdef CONFIG_PM_SLEEP
799 static int gpio_keys_suspend(struct device *dev)
800 {
801         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
802         struct input_dev *input = ddata->input;
803         int i;
804 
805         if (device_may_wakeup(dev)) {
806                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
807                         struct gpio_button_data *bdata = &ddata->data[i];
808                         if (bdata->button->wakeup)
809                                 enable_irq_wake(bdata->irq);
810                 }
811         } else {
812                 mutex_lock(&input->mutex);
813                 if (input->users)
814                         gpio_keys_close(input);
815                 mutex_unlock(&input->mutex);
816         }
817 
818         return 0;
819 }
820 
821 static int gpio_keys_resume(struct device *dev)
822 {
823         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
824         struct input_dev *input = ddata->input;
825         int error = 0;
826         int i;
827 
828         if (device_may_wakeup(dev)) {
829                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
830                         struct gpio_button_data *bdata = &ddata->data[i];
831                         if (bdata->button->wakeup)
832                                 disable_irq_wake(bdata->irq);
833                 }
834         } else {
835                 mutex_lock(&input->mutex);
836                 if (input->users)
837                         error = gpio_keys_open(input);
838                 mutex_unlock(&input->mutex);
839         }
840 
841         if (error)
842                 return error;
843 
844         gpio_keys_report_state(ddata);
845         return 0;
846 }
847 #endif
848 
849 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
850 
851 static struct platform_driver gpio_keys_device_driver = {
852         .probe          = gpio_keys_probe,
853         .remove         = gpio_keys_remove,
854         .driver         = {
855                 .name   = "gpio-keys",
856                 .pm     = &gpio_keys_pm_ops,
857                 .of_match_table = of_match_ptr(gpio_keys_of_match),
858         }
859 };
860 
861 static int __init gpio_keys_init(void)
862 {
863         return platform_driver_register(&gpio_keys_device_driver);
864 }
865 
866 static void __exit gpio_keys_exit(void)
867 {
868         platform_driver_unregister(&gpio_keys_device_driver);
869 }
870 
871 late_initcall(gpio_keys_init);
872 module_exit(gpio_keys_exit);
873 
874 MODULE_LICENSE("GPL");
875 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
876 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
877 MODULE_ALIAS("platform:gpio-keys");
878 

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