Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 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

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         mutex_lock(&ddata->disable_lock);
243 
244         for (i = 0; i < ddata->pdata->nbuttons; i++) {
245                 struct gpio_button_data *bdata = &ddata->data[i];
246 
247                 if (bdata->button->type != type)
248                         continue;
249 
250                 if (test_bit(bdata->button->code, bits))
251                         gpio_keys_disable_button(bdata);
252                 else
253                         gpio_keys_enable_button(bdata);
254         }
255 
256         mutex_unlock(&ddata->disable_lock);
257 
258 out:
259         kfree(bits);
260         return error;
261 }
262 
263 #define ATTR_SHOW_FN(name, type, only_disabled)                         \
264 static ssize_t gpio_keys_show_##name(struct device *dev,                \
265                                      struct device_attribute *attr,     \
266                                      char *buf)                         \
267 {                                                                       \
268         struct platform_device *pdev = to_platform_device(dev);         \
269         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
270                                                                         \
271         return gpio_keys_attr_show_helper(ddata, buf,                   \
272                                           type, only_disabled);         \
273 }
274 
275 ATTR_SHOW_FN(keys, EV_KEY, false);
276 ATTR_SHOW_FN(switches, EV_SW, false);
277 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
278 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
279 
280 /*
281  * ATTRIBUTES:
282  *
283  * /sys/devices/platform/gpio-keys/keys [ro]
284  * /sys/devices/platform/gpio-keys/switches [ro]
285  */
286 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
287 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
288 
289 #define ATTR_STORE_FN(name, type)                                       \
290 static ssize_t gpio_keys_store_##name(struct device *dev,               \
291                                       struct device_attribute *attr,    \
292                                       const char *buf,                  \
293                                       size_t count)                     \
294 {                                                                       \
295         struct platform_device *pdev = to_platform_device(dev);         \
296         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);   \
297         ssize_t error;                                                  \
298                                                                         \
299         error = gpio_keys_attr_store_helper(ddata, buf, type);          \
300         if (error)                                                      \
301                 return error;                                           \
302                                                                         \
303         return count;                                                   \
304 }
305 
306 ATTR_STORE_FN(disabled_keys, EV_KEY);
307 ATTR_STORE_FN(disabled_switches, EV_SW);
308 
309 /*
310  * ATTRIBUTES:
311  *
312  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
313  * /sys/devices/platform/gpio-keys/disables_switches [rw]
314  */
315 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
316                    gpio_keys_show_disabled_keys,
317                    gpio_keys_store_disabled_keys);
318 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
319                    gpio_keys_show_disabled_switches,
320                    gpio_keys_store_disabled_switches);
321 
322 static struct attribute *gpio_keys_attrs[] = {
323         &dev_attr_keys.attr,
324         &dev_attr_switches.attr,
325         &dev_attr_disabled_keys.attr,
326         &dev_attr_disabled_switches.attr,
327         NULL,
328 };
329 
330 static struct attribute_group gpio_keys_attr_group = {
331         .attrs = gpio_keys_attrs,
332 };
333 
334 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
335 {
336         const struct gpio_keys_button *button = bdata->button;
337         struct input_dev *input = bdata->input;
338         unsigned int type = button->type ?: EV_KEY;
339         int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
340 
341         if (type == EV_ABS) {
342                 if (state)
343                         input_event(input, type, button->code, button->value);
344         } else {
345                 input_event(input, type, button->code, !!state);
346         }
347         input_sync(input);
348 }
349 
350 static void gpio_keys_gpio_work_func(struct work_struct *work)
351 {
352         struct gpio_button_data *bdata =
353                 container_of(work, struct gpio_button_data, work.work);
354 
355         gpio_keys_gpio_report_event(bdata);
356 
357         if (bdata->button->wakeup)
358                 pm_relax(bdata->input->dev.parent);
359 }
360 
361 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
362 {
363         struct gpio_button_data *bdata = dev_id;
364 
365         BUG_ON(irq != bdata->irq);
366 
367         if (bdata->button->wakeup)
368                 pm_stay_awake(bdata->input->dev.parent);
369 
370         mod_delayed_work(system_wq,
371                          &bdata->work,
372                          msecs_to_jiffies(bdata->software_debounce));
373 
374         return IRQ_HANDLED;
375 }
376 
377 static void gpio_keys_irq_timer(unsigned long _data)
378 {
379         struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
380         struct input_dev *input = bdata->input;
381         unsigned long flags;
382 
383         spin_lock_irqsave(&bdata->lock, flags);
384         if (bdata->key_pressed) {
385                 input_event(input, EV_KEY, bdata->button->code, 0);
386                 input_sync(input);
387                 bdata->key_pressed = false;
388         }
389         spin_unlock_irqrestore(&bdata->lock, flags);
390 }
391 
392 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
393 {
394         struct gpio_button_data *bdata = dev_id;
395         const struct gpio_keys_button *button = bdata->button;
396         struct input_dev *input = bdata->input;
397         unsigned long flags;
398 
399         BUG_ON(irq != bdata->irq);
400 
401         spin_lock_irqsave(&bdata->lock, flags);
402 
403         if (!bdata->key_pressed) {
404                 if (bdata->button->wakeup)
405                         pm_wakeup_event(bdata->input->dev.parent, 0);
406 
407                 input_event(input, EV_KEY, button->code, 1);
408                 input_sync(input);
409 
410                 if (!bdata->release_delay) {
411                         input_event(input, EV_KEY, button->code, 0);
412                         input_sync(input);
413                         goto out;
414                 }
415 
416                 bdata->key_pressed = true;
417         }
418 
419         if (bdata->release_delay)
420                 mod_timer(&bdata->release_timer,
421                         jiffies + msecs_to_jiffies(bdata->release_delay));
422 out:
423         spin_unlock_irqrestore(&bdata->lock, flags);
424         return IRQ_HANDLED;
425 }
426 
427 static void gpio_keys_quiesce_key(void *data)
428 {
429         struct gpio_button_data *bdata = data;
430 
431         if (gpio_is_valid(bdata->button->gpio))
432                 cancel_delayed_work_sync(&bdata->work);
433         else
434                 del_timer_sync(&bdata->release_timer);
435 }
436 
437 static int gpio_keys_setup_key(struct platform_device *pdev,
438                                 struct input_dev *input,
439                                 struct gpio_button_data *bdata,
440                                 const struct gpio_keys_button *button)
441 {
442         const char *desc = button->desc ? button->desc : "gpio_keys";
443         struct device *dev = &pdev->dev;
444         irq_handler_t isr;
445         unsigned long irqflags;
446         int irq;
447         int error;
448 
449         bdata->input = input;
450         bdata->button = button;
451         spin_lock_init(&bdata->lock);
452 
453         if (gpio_is_valid(button->gpio)) {
454 
455                 error = devm_gpio_request_one(&pdev->dev, button->gpio,
456                                               GPIOF_IN, desc);
457                 if (error < 0) {
458                         dev_err(dev, "Failed to request GPIO %d, error %d\n",
459                                 button->gpio, error);
460                         return error;
461                 }
462 
463                 if (button->debounce_interval) {
464                         error = gpio_set_debounce(button->gpio,
465                                         button->debounce_interval * 1000);
466                         /* use timer if gpiolib doesn't provide debounce */
467                         if (error < 0)
468                                 bdata->software_debounce =
469                                                 button->debounce_interval;
470                 }
471 
472                 if (button->irq) {
473                         bdata->irq = button->irq;
474                 } else {
475                         irq = gpio_to_irq(button->gpio);
476                         if (irq < 0) {
477                                 error = irq;
478                                 dev_err(dev,
479                                         "Unable to get irq number for GPIO %d, error %d\n",
480                                         button->gpio, error);
481                                 return error;
482                         }
483                         bdata->irq = irq;
484                 }
485 
486                 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
487 
488                 isr = gpio_keys_gpio_isr;
489                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
490 
491         } else {
492                 if (!button->irq) {
493                         dev_err(dev, "No IRQ specified\n");
494                         return -EINVAL;
495                 }
496                 bdata->irq = button->irq;
497 
498                 if (button->type && button->type != EV_KEY) {
499                         dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
500                         return -EINVAL;
501                 }
502 
503                 bdata->release_delay = button->debounce_interval;
504                 setup_timer(&bdata->release_timer,
505                             gpio_keys_irq_timer, (unsigned long)bdata);
506 
507                 isr = gpio_keys_irq_isr;
508                 irqflags = 0;
509         }
510 
511         input_set_capability(input, button->type ?: EV_KEY, button->code);
512 
513         /*
514          * Install custom action to cancel release timer and
515          * workqueue item.
516          */
517         error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
518         if (error) {
519                 dev_err(&pdev->dev,
520                         "failed to register quiesce action, error: %d\n",
521                         error);
522                 return error;
523         }
524 
525         /*
526          * If platform has specified that the button can be disabled,
527          * we don't want it to share the interrupt line.
528          */
529         if (!button->can_disable)
530                 irqflags |= IRQF_SHARED;
531 
532         error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
533                                              isr, irqflags, desc, bdata);
534         if (error < 0) {
535                 dev_err(dev, "Unable to claim irq %d; error %d\n",
536                         bdata->irq, error);
537                 return error;
538         }
539 
540         return 0;
541 }
542 
543 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
544 {
545         struct input_dev *input = ddata->input;
546         int i;
547 
548         for (i = 0; i < ddata->pdata->nbuttons; i++) {
549                 struct gpio_button_data *bdata = &ddata->data[i];
550                 if (gpio_is_valid(bdata->button->gpio))
551                         gpio_keys_gpio_report_event(bdata);
552         }
553         input_sync(input);
554 }
555 
556 static int gpio_keys_open(struct input_dev *input)
557 {
558         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
559         const struct gpio_keys_platform_data *pdata = ddata->pdata;
560         int error;
561 
562         if (pdata->enable) {
563                 error = pdata->enable(input->dev.parent);
564                 if (error)
565                         return error;
566         }
567 
568         /* Report current state of buttons that are connected to GPIOs */
569         gpio_keys_report_state(ddata);
570 
571         return 0;
572 }
573 
574 static void gpio_keys_close(struct input_dev *input)
575 {
576         struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
577         const struct gpio_keys_platform_data *pdata = ddata->pdata;
578 
579         if (pdata->disable)
580                 pdata->disable(input->dev.parent);
581 }
582 
583 /*
584  * Handlers for alternative sources of platform_data
585  */
586 
587 #ifdef CONFIG_OF
588 /*
589  * Translate OpenFirmware node properties into platform_data
590  */
591 static struct gpio_keys_platform_data *
592 gpio_keys_get_devtree_pdata(struct device *dev)
593 {
594         struct device_node *node, *pp;
595         struct gpio_keys_platform_data *pdata;
596         struct gpio_keys_button *button;
597         int error;
598         int nbuttons;
599         int i;
600 
601         node = dev->of_node;
602         if (!node)
603                 return ERR_PTR(-ENODEV);
604 
605         nbuttons = of_get_child_count(node);
606         if (nbuttons == 0)
607                 return ERR_PTR(-ENODEV);
608 
609         pdata = devm_kzalloc(dev,
610                              sizeof(*pdata) + nbuttons * sizeof(*button),
611                              GFP_KERNEL);
612         if (!pdata)
613                 return ERR_PTR(-ENOMEM);
614 
615         pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
616         pdata->nbuttons = nbuttons;
617 
618         pdata->rep = !!of_get_property(node, "autorepeat", NULL);
619 
620         i = 0;
621         for_each_child_of_node(node, pp) {
622                 enum of_gpio_flags flags;
623 
624                 button = &pdata->buttons[i++];
625 
626                 button->gpio = of_get_gpio_flags(pp, 0, &flags);
627                 if (button->gpio < 0) {
628                         error = button->gpio;
629                         if (error != -ENOENT) {
630                                 if (error != -EPROBE_DEFER)
631                                         dev_err(dev,
632                                                 "Failed to get gpio flags, error: %d\n",
633                                                 error);
634                                 return ERR_PTR(error);
635                         }
636                 } else {
637                         button->active_low = flags & OF_GPIO_ACTIVE_LOW;
638                 }
639 
640                 button->irq = irq_of_parse_and_map(pp, 0);
641 
642                 if (!gpio_is_valid(button->gpio) && !button->irq) {
643                         dev_err(dev, "Found button without gpios or irqs\n");
644                         return ERR_PTR(-EINVAL);
645                 }
646 
647                 if (of_property_read_u32(pp, "linux,code", &button->code)) {
648                         dev_err(dev, "Button without keycode: 0x%x\n",
649                                 button->gpio);
650                         return ERR_PTR(-EINVAL);
651                 }
652 
653                 button->desc = of_get_property(pp, "label", NULL);
654 
655                 if (of_property_read_u32(pp, "linux,input-type", &button->type))
656                         button->type = EV_KEY;
657 
658                 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
659 
660                 button->can_disable = !!of_get_property(pp, "linux,can-disable", NULL);
661 
662                 if (of_property_read_u32(pp, "debounce-interval",
663                                          &button->debounce_interval))
664                         button->debounce_interval = 5;
665         }
666 
667         if (pdata->nbuttons == 0)
668                 return ERR_PTR(-EINVAL);
669 
670         return pdata;
671 }
672 
673 static const struct of_device_id gpio_keys_of_match[] = {
674         { .compatible = "gpio-keys", },
675         { },
676 };
677 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
678 
679 #else
680 
681 static inline struct gpio_keys_platform_data *
682 gpio_keys_get_devtree_pdata(struct device *dev)
683 {
684         return ERR_PTR(-ENODEV);
685 }
686 
687 #endif
688 
689 static int gpio_keys_probe(struct platform_device *pdev)
690 {
691         struct device *dev = &pdev->dev;
692         const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
693         struct gpio_keys_drvdata *ddata;
694         struct input_dev *input;
695         size_t size;
696         int i, error;
697         int wakeup = 0;
698 
699         if (!pdata) {
700                 pdata = gpio_keys_get_devtree_pdata(dev);
701                 if (IS_ERR(pdata))
702                         return PTR_ERR(pdata);
703         }
704 
705         size = sizeof(struct gpio_keys_drvdata) +
706                         pdata->nbuttons * sizeof(struct gpio_button_data);
707         ddata = devm_kzalloc(dev, size, GFP_KERNEL);
708         if (!ddata) {
709                 dev_err(dev, "failed to allocate state\n");
710                 return -ENOMEM;
711         }
712 
713         input = devm_input_allocate_device(dev);
714         if (!input) {
715                 dev_err(dev, "failed to allocate input device\n");
716                 return -ENOMEM;
717         }
718 
719         ddata->pdata = pdata;
720         ddata->input = input;
721         mutex_init(&ddata->disable_lock);
722 
723         platform_set_drvdata(pdev, ddata);
724         input_set_drvdata(input, ddata);
725 
726         input->name = pdata->name ? : pdev->name;
727         input->phys = "gpio-keys/input0";
728         input->dev.parent = &pdev->dev;
729         input->open = gpio_keys_open;
730         input->close = gpio_keys_close;
731 
732         input->id.bustype = BUS_HOST;
733         input->id.vendor = 0x0001;
734         input->id.product = 0x0001;
735         input->id.version = 0x0100;
736 
737         /* Enable auto repeat feature of Linux input subsystem */
738         if (pdata->rep)
739                 __set_bit(EV_REP, input->evbit);
740 
741         for (i = 0; i < pdata->nbuttons; i++) {
742                 const struct gpio_keys_button *button = &pdata->buttons[i];
743                 struct gpio_button_data *bdata = &ddata->data[i];
744 
745                 error = gpio_keys_setup_key(pdev, input, bdata, button);
746                 if (error)
747                         return error;
748 
749                 if (button->wakeup)
750                         wakeup = 1;
751         }
752 
753         error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
754         if (error) {
755                 dev_err(dev, "Unable to export keys/switches, error: %d\n",
756                         error);
757                 return error;
758         }
759 
760         error = input_register_device(input);
761         if (error) {
762                 dev_err(dev, "Unable to register input device, error: %d\n",
763                         error);
764                 goto err_remove_group;
765         }
766 
767         device_init_wakeup(&pdev->dev, wakeup);
768 
769         return 0;
770 
771 err_remove_group:
772         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
773         return error;
774 }
775 
776 static int gpio_keys_remove(struct platform_device *pdev)
777 {
778         sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
779 
780         device_init_wakeup(&pdev->dev, 0);
781 
782         return 0;
783 }
784 
785 #ifdef CONFIG_PM_SLEEP
786 static int gpio_keys_suspend(struct device *dev)
787 {
788         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
789         struct input_dev *input = ddata->input;
790         int i;
791 
792         if (device_may_wakeup(dev)) {
793                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
794                         struct gpio_button_data *bdata = &ddata->data[i];
795                         if (bdata->button->wakeup)
796                                 enable_irq_wake(bdata->irq);
797                 }
798         } else {
799                 mutex_lock(&input->mutex);
800                 if (input->users)
801                         gpio_keys_close(input);
802                 mutex_unlock(&input->mutex);
803         }
804 
805         return 0;
806 }
807 
808 static int gpio_keys_resume(struct device *dev)
809 {
810         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
811         struct input_dev *input = ddata->input;
812         int error = 0;
813         int i;
814 
815         if (device_may_wakeup(dev)) {
816                 for (i = 0; i < ddata->pdata->nbuttons; i++) {
817                         struct gpio_button_data *bdata = &ddata->data[i];
818                         if (bdata->button->wakeup)
819                                 disable_irq_wake(bdata->irq);
820                 }
821         } else {
822                 mutex_lock(&input->mutex);
823                 if (input->users)
824                         error = gpio_keys_open(input);
825                 mutex_unlock(&input->mutex);
826         }
827 
828         if (error)
829                 return error;
830 
831         gpio_keys_report_state(ddata);
832         return 0;
833 }
834 #endif
835 
836 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
837 
838 static struct platform_driver gpio_keys_device_driver = {
839         .probe          = gpio_keys_probe,
840         .remove         = gpio_keys_remove,
841         .driver         = {
842                 .name   = "gpio-keys",
843                 .pm     = &gpio_keys_pm_ops,
844                 .of_match_table = of_match_ptr(gpio_keys_of_match),
845         }
846 };
847 
848 static int __init gpio_keys_init(void)
849 {
850         return platform_driver_register(&gpio_keys_device_driver);
851 }
852 
853 static void __exit gpio_keys_exit(void)
854 {
855         platform_driver_unregister(&gpio_keys_device_driver);
856 }
857 
858 late_initcall(gpio_keys_init);
859 module_exit(gpio_keys_exit);
860 
861 MODULE_LICENSE("GPL");
862 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
863 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
864 MODULE_ALIAS("platform:gpio-keys");
865 

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