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/spinlock.h>
33 
34 struct gpio_button_data {
35 	const struct gpio_keys_button *button;
36 	struct input_dev *input;
37 	struct timer_list timer;
38 	struct work_struct work;
39 	unsigned int timer_debounce;	/* in msecs */
40 	unsigned int irq;
41 	spinlock_t lock;
42 	bool disabled;
43 	bool key_pressed;
44 };
45 
46 struct gpio_keys_drvdata {
47 	const struct gpio_keys_platform_data *pdata;
48 	struct input_dev *input;
49 	struct mutex disable_lock;
50 	struct gpio_button_data data[0];
51 };
52 
53 /*
54  * SYSFS interface for enabling/disabling keys and switches:
55  *
56  * There are 4 attributes under /sys/devices/platform/gpio-keys/
57  *	keys [ro]              - bitmap of keys (EV_KEY) which can be
58  *	                         disabled
59  *	switches [ro]          - bitmap of switches (EV_SW) which can be
60  *	                         disabled
61  *	disabled_keys [rw]     - bitmap of keys currently disabled
62  *	disabled_switches [rw] - bitmap of switches currently disabled
63  *
64  * Userland can change these values and hence disable event generation
65  * for each key (or switch). Disabling a key means its interrupt line
66  * is disabled.
67  *
68  * For example, if we have following switches set up as gpio-keys:
69  *	SW_DOCK = 5
70  *	SW_CAMERA_LENS_COVER = 9
71  *	SW_KEYPAD_SLIDE = 10
72  *	SW_FRONT_PROXIMITY = 11
73  * This is read from switches:
74  *	11-9,5
75  * Next we want to disable proximity (11) and dock (5), we write:
76  *	11,5
77  * to file disabled_switches. Now proximity and dock IRQs are disabled.
78  * This can be verified by reading the file disabled_switches:
79  *	11,5
80  * If we now want to enable proximity (11) switch we write:
81  *	5
82  * to disabled_switches.
83  *
84  * We can disable only those keys which don't allow sharing the irq.
85  */
86 
87 /**
88  * get_n_events_by_type() - returns maximum number of events per @type
89  * @type: type of button (%EV_KEY, %EV_SW)
90  *
91  * Return value of this function can be used to allocate bitmap
92  * large enough to hold all bits for given type.
93  */
94 static inline int get_n_events_by_type(int type)
95 {
96 	BUG_ON(type != EV_SW && type != EV_KEY);
97 
98 	return (type == EV_KEY) ? KEY_CNT : SW_CNT;
99 }
100 
101 /**
102  * gpio_keys_disable_button() - disables given GPIO button
103  * @bdata: button data for button to be disabled
104  *
105  * Disables button pointed by @bdata. This is done by masking
106  * IRQ line. After this function is called, button won't generate
107  * input events anymore. Note that one can only disable buttons
108  * that don't share IRQs.
109  *
110  * Make sure that @bdata->disable_lock is locked when entering
111  * this function to avoid races when concurrent threads are
112  * disabling buttons at the same time.
113  */
114 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
115 {
116 	if (!bdata->disabled) {
117 		/*
118 		 * Disable IRQ and possible debouncing timer.
119 		 */
120 		disable_irq(bdata->irq);
121 		if (bdata->timer_debounce)
122 			del_timer_sync(&bdata->timer);
123 
124 		bdata->disabled = true;
125 	}
126 }
127 
128 /**
129  * gpio_keys_enable_button() - enables given GPIO button
130  * @bdata: button data for button to be disabled
131  *
132  * Enables given button pointed by @bdata.
133  *
134  * Make sure that @bdata->disable_lock is locked when entering
135  * this function to avoid races with concurrent threads trying
136  * to enable the same button at the same time.
137  */
138 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
139 {
140 	if (bdata->disabled) {
141 		enable_irq(bdata->irq);
142 		bdata->disabled = false;
143 	}
144 }
145 
146 /**
147  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
148  * @ddata: pointer to drvdata
149  * @buf: buffer where stringified bitmap is written
150  * @type: button type (%EV_KEY, %EV_SW)
151  * @only_disabled: does caller want only those buttons that are
152  *                 currently disabled or all buttons that can be
153  *                 disabled
154  *
155  * This function writes buttons that can be disabled to @buf. If
156  * @only_disabled is true, then @buf contains only those buttons
157  * that are currently disabled. Returns 0 on success or negative
158  * errno on failure.
159  */
160 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
161 					  char *buf, unsigned int type,
162 					  bool only_disabled)
163 {
164 	int n_events = get_n_events_by_type(type);
165 	unsigned long *bits;
166 	ssize_t ret;
167 	int i;
168 
169 	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
170 	if (!bits)
171 		return -ENOMEM;
172 
173 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
174 		struct gpio_button_data *bdata = &ddata->data[i];
175 
176 		if (bdata->button->type != type)
177 			continue;
178 
179 		if (only_disabled && !bdata->disabled)
180 			continue;
181 
182 		__set_bit(bdata->button->code, bits);
183 	}
184 
185 	ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
186 	buf[ret++] = '\n';
187 	buf[ret] = '\0';
188 
189 	kfree(bits);
190 
191 	return ret;
192 }
193 
194 /**
195  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
196  * @ddata: pointer to drvdata
197  * @buf: buffer from userspace that contains stringified bitmap
198  * @type: button type (%EV_KEY, %EV_SW)
199  *
200  * This function parses stringified bitmap from @buf and disables/enables
201  * GPIO buttons accordingly. Returns 0 on success and negative error
202  * on failure.
203  */
204 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
205 					   const char *buf, unsigned int type)
206 {
207 	int n_events = get_n_events_by_type(type);
208 	unsigned long *bits;
209 	ssize_t error;
210 	int i;
211 
212 	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
213 	if (!bits)
214 		return -ENOMEM;
215 
216 	error = bitmap_parselist(buf, bits, n_events);
217 	if (error)
218 		goto out;
219 
220 	/* First validate */
221 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
222 		struct gpio_button_data *bdata = &ddata->data[i];
223 
224 		if (bdata->button->type != type)
225 			continue;
226 
227 		if (test_bit(bdata->button->code, bits) &&
228 		    !bdata->button->can_disable) {
229 			error = -EINVAL;
230 			goto out;
231 		}
232 	}
233 
234 	mutex_lock(&ddata->disable_lock);
235 
236 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
237 		struct gpio_button_data *bdata = &ddata->data[i];
238 
239 		if (bdata->button->type != type)
240 			continue;
241 
242 		if (test_bit(bdata->button->code, bits))
243 			gpio_keys_disable_button(bdata);
244 		else
245 			gpio_keys_enable_button(bdata);
246 	}
247 
248 	mutex_unlock(&ddata->disable_lock);
249 
250 out:
251 	kfree(bits);
252 	return error;
253 }
254 
255 #define ATTR_SHOW_FN(name, type, only_disabled)				\
256 static ssize_t gpio_keys_show_##name(struct device *dev,		\
257 				     struct device_attribute *attr,	\
258 				     char *buf)				\
259 {									\
260 	struct platform_device *pdev = to_platform_device(dev);		\
261 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
262 									\
263 	return gpio_keys_attr_show_helper(ddata, buf,			\
264 					  type, only_disabled);		\
265 }
266 
267 ATTR_SHOW_FN(keys, EV_KEY, false);
268 ATTR_SHOW_FN(switches, EV_SW, false);
269 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
270 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
271 
272 /*
273  * ATTRIBUTES:
274  *
275  * /sys/devices/platform/gpio-keys/keys [ro]
276  * /sys/devices/platform/gpio-keys/switches [ro]
277  */
278 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
279 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
280 
281 #define ATTR_STORE_FN(name, type)					\
282 static ssize_t gpio_keys_store_##name(struct device *dev,		\
283 				      struct device_attribute *attr,	\
284 				      const char *buf,			\
285 				      size_t count)			\
286 {									\
287 	struct platform_device *pdev = to_platform_device(dev);		\
288 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
289 	ssize_t error;							\
290 									\
291 	error = gpio_keys_attr_store_helper(ddata, buf, type);		\
292 	if (error)							\
293 		return error;						\
294 									\
295 	return count;							\
296 }
297 
298 ATTR_STORE_FN(disabled_keys, EV_KEY);
299 ATTR_STORE_FN(disabled_switches, EV_SW);
300 
301 /*
302  * ATTRIBUTES:
303  *
304  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
305  * /sys/devices/platform/gpio-keys/disables_switches [rw]
306  */
307 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
308 		   gpio_keys_show_disabled_keys,
309 		   gpio_keys_store_disabled_keys);
310 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
311 		   gpio_keys_show_disabled_switches,
312 		   gpio_keys_store_disabled_switches);
313 
314 static struct attribute *gpio_keys_attrs[] = {
315 	&dev_attr_keys.attr,
316 	&dev_attr_switches.attr,
317 	&dev_attr_disabled_keys.attr,
318 	&dev_attr_disabled_switches.attr,
319 	NULL,
320 };
321 
322 static struct attribute_group gpio_keys_attr_group = {
323 	.attrs = gpio_keys_attrs,
324 };
325 
326 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
327 {
328 	const struct gpio_keys_button *button = bdata->button;
329 	struct input_dev *input = bdata->input;
330 	unsigned int type = button->type ?: EV_KEY;
331 	int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
332 
333 	if (type == EV_ABS) {
334 		if (state)
335 			input_event(input, type, button->code, button->value);
336 	} else {
337 		input_event(input, type, button->code, !!state);
338 	}
339 	input_sync(input);
340 }
341 
342 static void gpio_keys_gpio_work_func(struct work_struct *work)
343 {
344 	struct gpio_button_data *bdata =
345 		container_of(work, struct gpio_button_data, work);
346 
347 	gpio_keys_gpio_report_event(bdata);
348 
349 	if (bdata->button->wakeup)
350 		pm_relax(bdata->input->dev.parent);
351 }
352 
353 static void gpio_keys_gpio_timer(unsigned long _data)
354 {
355 	struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
356 
357 	schedule_work(&bdata->work);
358 }
359 
360 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
361 {
362 	struct gpio_button_data *bdata = dev_id;
363 
364 	BUG_ON(irq != bdata->irq);
365 
366 	if (bdata->button->wakeup)
367 		pm_stay_awake(bdata->input->dev.parent);
368 	if (bdata->timer_debounce)
369 		mod_timer(&bdata->timer,
370 			jiffies + msecs_to_jiffies(bdata->timer_debounce));
371 	else
372 		schedule_work(&bdata->work);
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->timer_debounce) {
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->timer_debounce)
420 		mod_timer(&bdata->timer,
421 			jiffies + msecs_to_jiffies(bdata->timer_debounce));
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 (bdata->timer_debounce)
432 		del_timer_sync(&bdata->timer);
433 
434 	cancel_work_sync(&bdata->work);
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->timer_debounce =
469 						button->debounce_interval;
470 		}
471 
472 		irq = gpio_to_irq(button->gpio);
473 		if (irq < 0) {
474 			error = irq;
475 			dev_err(dev,
476 				"Unable to get irq number for GPIO %d, error %d\n",
477 				button->gpio, error);
478 			return error;
479 		}
480 		bdata->irq = irq;
481 
482 		INIT_WORK(&bdata->work, gpio_keys_gpio_work_func);
483 		setup_timer(&bdata->timer,
484 			    gpio_keys_gpio_timer, (unsigned long)bdata);
485 
486 		isr = gpio_keys_gpio_isr;
487 		irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
488 
489 	} else {
490 		if (!button->irq) {
491 			dev_err(dev, "No IRQ specified\n");
492 			return -EINVAL;
493 		}
494 		bdata->irq = button->irq;
495 
496 		if (button->type && button->type != EV_KEY) {
497 			dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
498 			return -EINVAL;
499 		}
500 
501 		bdata->timer_debounce = button->debounce_interval;
502 		setup_timer(&bdata->timer,
503 			    gpio_keys_irq_timer, (unsigned long)bdata);
504 
505 		isr = gpio_keys_irq_isr;
506 		irqflags = 0;
507 	}
508 
509 	input_set_capability(input, button->type ?: EV_KEY, button->code);
510 
511 	/*
512 	 * Install custom action to cancel debounce timer and
513 	 * workqueue item.
514 	 */
515 	error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
516 	if (error) {
517 		dev_err(&pdev->dev,
518 			"failed to register quiesce action, error: %d\n",
519 			error);
520 		return error;
521 	}
522 
523 	/*
524 	 * If platform has specified that the button can be disabled,
525 	 * we don't want it to share the interrupt line.
526 	 */
527 	if (!button->can_disable)
528 		irqflags |= IRQF_SHARED;
529 
530 	error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
531 					     isr, irqflags, desc, bdata);
532 	if (error < 0) {
533 		dev_err(dev, "Unable to claim irq %d; error %d\n",
534 			bdata->irq, error);
535 		return error;
536 	}
537 
538 	return 0;
539 }
540 
541 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
542 {
543 	struct input_dev *input = ddata->input;
544 	int i;
545 
546 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
547 		struct gpio_button_data *bdata = &ddata->data[i];
548 		if (gpio_is_valid(bdata->button->gpio))
549 			gpio_keys_gpio_report_event(bdata);
550 	}
551 	input_sync(input);
552 }
553 
554 static int gpio_keys_open(struct input_dev *input)
555 {
556 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
557 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
558 	int error;
559 
560 	if (pdata->enable) {
561 		error = pdata->enable(input->dev.parent);
562 		if (error)
563 			return error;
564 	}
565 
566 	/* Report current state of buttons that are connected to GPIOs */
567 	gpio_keys_report_state(ddata);
568 
569 	return 0;
570 }
571 
572 static void gpio_keys_close(struct input_dev *input)
573 {
574 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
575 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
576 
577 	if (pdata->disable)
578 		pdata->disable(input->dev.parent);
579 }
580 
581 /*
582  * Handlers for alternative sources of platform_data
583  */
584 
585 #ifdef CONFIG_OF
586 /*
587  * Translate OpenFirmware node properties into platform_data
588  */
589 static struct gpio_keys_platform_data *
590 gpio_keys_get_devtree_pdata(struct device *dev)
591 {
592 	struct device_node *node, *pp;
593 	struct gpio_keys_platform_data *pdata;
594 	struct gpio_keys_button *button;
595 	int error;
596 	int nbuttons;
597 	int i;
598 
599 	node = dev->of_node;
600 	if (!node)
601 		return ERR_PTR(-ENODEV);
602 
603 	nbuttons = of_get_child_count(node);
604 	if (nbuttons == 0)
605 		return ERR_PTR(-ENODEV);
606 
607 	pdata = devm_kzalloc(dev,
608 			     sizeof(*pdata) + nbuttons * sizeof(*button),
609 			     GFP_KERNEL);
610 	if (!pdata)
611 		return ERR_PTR(-ENOMEM);
612 
613 	pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
614 	pdata->nbuttons = nbuttons;
615 
616 	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
617 
618 	i = 0;
619 	for_each_child_of_node(node, pp) {
620 		int gpio;
621 		enum of_gpio_flags flags;
622 
623 		if (!of_find_property(pp, "gpios", NULL)) {
624 			pdata->nbuttons--;
625 			dev_warn(dev, "Found button without gpios\n");
626 			continue;
627 		}
628 
629 		gpio = of_get_gpio_flags(pp, 0, &flags);
630 		if (gpio < 0) {
631 			error = gpio;
632 			if (error != -EPROBE_DEFER)
633 				dev_err(dev,
634 					"Failed to get gpio flags, error: %d\n",
635 					error);
636 			return ERR_PTR(error);
637 		}
638 
639 		button = &pdata->buttons[i++];
640 
641 		button->gpio = gpio;
642 		button->active_low = flags & OF_GPIO_ACTIVE_LOW;
643 
644 		if (of_property_read_u32(pp, "linux,code", &button->code)) {
645 			dev_err(dev, "Button without keycode: 0x%x\n",
646 				button->gpio);
647 			return ERR_PTR(-EINVAL);
648 		}
649 
650 		button->desc = of_get_property(pp, "label", NULL);
651 
652 		if (of_property_read_u32(pp, "linux,input-type", &button->type))
653 			button->type = EV_KEY;
654 
655 		button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
656 
657 		if (of_property_read_u32(pp, "debounce-interval",
658 					 &button->debounce_interval))
659 			button->debounce_interval = 5;
660 	}
661 
662 	if (pdata->nbuttons == 0)
663 		return ERR_PTR(-EINVAL);
664 
665 	return pdata;
666 }
667 
668 static const struct of_device_id gpio_keys_of_match[] = {
669 	{ .compatible = "gpio-keys", },
670 	{ },
671 };
672 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
673 
674 #else
675 
676 static inline struct gpio_keys_platform_data *
677 gpio_keys_get_devtree_pdata(struct device *dev)
678 {
679 	return ERR_PTR(-ENODEV);
680 }
681 
682 #endif
683 
684 static int gpio_keys_probe(struct platform_device *pdev)
685 {
686 	struct device *dev = &pdev->dev;
687 	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
688 	struct gpio_keys_drvdata *ddata;
689 	struct input_dev *input;
690 	size_t size;
691 	int i, error;
692 	int wakeup = 0;
693 
694 	if (!pdata) {
695 		pdata = gpio_keys_get_devtree_pdata(dev);
696 		if (IS_ERR(pdata))
697 			return PTR_ERR(pdata);
698 	}
699 
700 	size = sizeof(struct gpio_keys_drvdata) +
701 			pdata->nbuttons * sizeof(struct gpio_button_data);
702 	ddata = devm_kzalloc(dev, size, GFP_KERNEL);
703 	if (!ddata) {
704 		dev_err(dev, "failed to allocate state\n");
705 		return -ENOMEM;
706 	}
707 
708 	input = devm_input_allocate_device(dev);
709 	if (!input) {
710 		dev_err(dev, "failed to allocate input device\n");
711 		return -ENOMEM;
712 	}
713 
714 	ddata->pdata = pdata;
715 	ddata->input = input;
716 	mutex_init(&ddata->disable_lock);
717 
718 	platform_set_drvdata(pdev, ddata);
719 	input_set_drvdata(input, ddata);
720 
721 	input->name = pdata->name ? : pdev->name;
722 	input->phys = "gpio-keys/input0";
723 	input->dev.parent = &pdev->dev;
724 	input->open = gpio_keys_open;
725 	input->close = gpio_keys_close;
726 
727 	input->id.bustype = BUS_HOST;
728 	input->id.vendor = 0x0001;
729 	input->id.product = 0x0001;
730 	input->id.version = 0x0100;
731 
732 	/* Enable auto repeat feature of Linux input subsystem */
733 	if (pdata->rep)
734 		__set_bit(EV_REP, input->evbit);
735 
736 	for (i = 0; i < pdata->nbuttons; i++) {
737 		const struct gpio_keys_button *button = &pdata->buttons[i];
738 		struct gpio_button_data *bdata = &ddata->data[i];
739 
740 		error = gpio_keys_setup_key(pdev, input, bdata, button);
741 		if (error)
742 			return error;
743 
744 		if (button->wakeup)
745 			wakeup = 1;
746 	}
747 
748 	error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
749 	if (error) {
750 		dev_err(dev, "Unable to export keys/switches, error: %d\n",
751 			error);
752 		return error;
753 	}
754 
755 	error = input_register_device(input);
756 	if (error) {
757 		dev_err(dev, "Unable to register input device, error: %d\n",
758 			error);
759 		goto err_remove_group;
760 	}
761 
762 	device_init_wakeup(&pdev->dev, wakeup);
763 
764 	return 0;
765 
766 err_remove_group:
767 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
768 	return error;
769 }
770 
771 static int gpio_keys_remove(struct platform_device *pdev)
772 {
773 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
774 
775 	device_init_wakeup(&pdev->dev, 0);
776 
777 	return 0;
778 }
779 
780 #ifdef CONFIG_PM_SLEEP
781 static int gpio_keys_suspend(struct device *dev)
782 {
783 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
784 	struct input_dev *input = ddata->input;
785 	int i;
786 
787 	if (device_may_wakeup(dev)) {
788 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
789 			struct gpio_button_data *bdata = &ddata->data[i];
790 			if (bdata->button->wakeup)
791 				enable_irq_wake(bdata->irq);
792 		}
793 	} else {
794 		mutex_lock(&input->mutex);
795 		if (input->users)
796 			gpio_keys_close(input);
797 		mutex_unlock(&input->mutex);
798 	}
799 
800 	return 0;
801 }
802 
803 static int gpio_keys_resume(struct device *dev)
804 {
805 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
806 	struct input_dev *input = ddata->input;
807 	int error = 0;
808 	int i;
809 
810 	if (device_may_wakeup(dev)) {
811 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
812 			struct gpio_button_data *bdata = &ddata->data[i];
813 			if (bdata->button->wakeup)
814 				disable_irq_wake(bdata->irq);
815 		}
816 	} else {
817 		mutex_lock(&input->mutex);
818 		if (input->users)
819 			error = gpio_keys_open(input);
820 		mutex_unlock(&input->mutex);
821 	}
822 
823 	if (error)
824 		return error;
825 
826 	gpio_keys_report_state(ddata);
827 	return 0;
828 }
829 #endif
830 
831 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
832 
833 static struct platform_driver gpio_keys_device_driver = {
834 	.probe		= gpio_keys_probe,
835 	.remove		= gpio_keys_remove,
836 	.driver		= {
837 		.name	= "gpio-keys",
838 		.owner	= THIS_MODULE,
839 		.pm	= &gpio_keys_pm_ops,
840 		.of_match_table = of_match_ptr(gpio_keys_of_match),
841 	}
842 };
843 
844 static int __init gpio_keys_init(void)
845 {
846 	return platform_driver_register(&gpio_keys_device_driver);
847 }
848 
849 static void __exit gpio_keys_exit(void)
850 {
851 	platform_driver_unregister(&gpio_keys_device_driver);
852 }
853 
854 late_initcall(gpio_keys_init);
855 module_exit(gpio_keys_exit);
856 
857 MODULE_LICENSE("GPL");
858 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
859 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
860 MODULE_ALIAS("platform:gpio-keys");
861