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 int gpio_keys_setup_key(struct platform_device *pdev,
428 				struct input_dev *input,
429 				struct gpio_button_data *bdata,
430 				const struct gpio_keys_button *button)
431 {
432 	const char *desc = button->desc ? button->desc : "gpio_keys";
433 	struct device *dev = &pdev->dev;
434 	irq_handler_t isr;
435 	unsigned long irqflags;
436 	int irq, error;
437 
438 	bdata->input = input;
439 	bdata->button = button;
440 	spin_lock_init(&bdata->lock);
441 
442 	if (gpio_is_valid(button->gpio)) {
443 
444 		error = gpio_request_one(button->gpio, GPIOF_IN, desc);
445 		if (error < 0) {
446 			dev_err(dev, "Failed to request GPIO %d, error %d\n",
447 				button->gpio, error);
448 			return error;
449 		}
450 
451 		if (button->debounce_interval) {
452 			error = gpio_set_debounce(button->gpio,
453 					button->debounce_interval * 1000);
454 			/* use timer if gpiolib doesn't provide debounce */
455 			if (error < 0)
456 				bdata->timer_debounce =
457 						button->debounce_interval;
458 		}
459 
460 		irq = gpio_to_irq(button->gpio);
461 		if (irq < 0) {
462 			error = irq;
463 			dev_err(dev,
464 				"Unable to get irq number for GPIO %d, error %d\n",
465 				button->gpio, error);
466 			goto fail;
467 		}
468 		bdata->irq = irq;
469 
470 		INIT_WORK(&bdata->work, gpio_keys_gpio_work_func);
471 		setup_timer(&bdata->timer,
472 			    gpio_keys_gpio_timer, (unsigned long)bdata);
473 
474 		isr = gpio_keys_gpio_isr;
475 		irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
476 
477 	} else {
478 		if (!button->irq) {
479 			dev_err(dev, "No IRQ specified\n");
480 			return -EINVAL;
481 		}
482 		bdata->irq = button->irq;
483 
484 		if (button->type && button->type != EV_KEY) {
485 			dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
486 			return -EINVAL;
487 		}
488 
489 		bdata->timer_debounce = button->debounce_interval;
490 		setup_timer(&bdata->timer,
491 			    gpio_keys_irq_timer, (unsigned long)bdata);
492 
493 		isr = gpio_keys_irq_isr;
494 		irqflags = 0;
495 	}
496 
497 	input_set_capability(input, button->type ?: EV_KEY, button->code);
498 
499 	/*
500 	 * If platform has specified that the button can be disabled,
501 	 * we don't want it to share the interrupt line.
502 	 */
503 	if (!button->can_disable)
504 		irqflags |= IRQF_SHARED;
505 
506 	error = request_any_context_irq(bdata->irq, isr, irqflags, desc, bdata);
507 	if (error < 0) {
508 		dev_err(dev, "Unable to claim irq %d; error %d\n",
509 			bdata->irq, error);
510 		goto fail;
511 	}
512 
513 	return 0;
514 
515 fail:
516 	if (gpio_is_valid(button->gpio))
517 		gpio_free(button->gpio);
518 
519 	return error;
520 }
521 
522 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
523 {
524 	struct input_dev *input = ddata->input;
525 	int i;
526 
527 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
528 		struct gpio_button_data *bdata = &ddata->data[i];
529 		if (gpio_is_valid(bdata->button->gpio))
530 			gpio_keys_gpio_report_event(bdata);
531 	}
532 	input_sync(input);
533 }
534 
535 static int gpio_keys_open(struct input_dev *input)
536 {
537 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
538 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
539 	int error;
540 
541 	if (pdata->enable) {
542 		error = pdata->enable(input->dev.parent);
543 		if (error)
544 			return error;
545 	}
546 
547 	/* Report current state of buttons that are connected to GPIOs */
548 	gpio_keys_report_state(ddata);
549 
550 	return 0;
551 }
552 
553 static void gpio_keys_close(struct input_dev *input)
554 {
555 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
556 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
557 
558 	if (pdata->disable)
559 		pdata->disable(input->dev.parent);
560 }
561 
562 /*
563  * Handlers for alternative sources of platform_data
564  */
565 
566 #ifdef CONFIG_OF
567 /*
568  * Translate OpenFirmware node properties into platform_data
569  */
570 static struct gpio_keys_platform_data *
571 gpio_keys_get_devtree_pdata(struct device *dev)
572 {
573 	struct device_node *node, *pp;
574 	struct gpio_keys_platform_data *pdata;
575 	struct gpio_keys_button *button;
576 	int error;
577 	int nbuttons;
578 	int i;
579 
580 	node = dev->of_node;
581 	if (!node) {
582 		error = -ENODEV;
583 		goto err_out;
584 	}
585 
586 	nbuttons = of_get_child_count(node);
587 	if (nbuttons == 0) {
588 		error = -ENODEV;
589 		goto err_out;
590 	}
591 
592 	pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
593 			GFP_KERNEL);
594 	if (!pdata) {
595 		error = -ENOMEM;
596 		goto err_out;
597 	}
598 
599 	pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
600 	pdata->nbuttons = nbuttons;
601 
602 	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
603 
604 	i = 0;
605 	for_each_child_of_node(node, pp) {
606 		int gpio;
607 		enum of_gpio_flags flags;
608 
609 		if (!of_find_property(pp, "gpios", NULL)) {
610 			pdata->nbuttons--;
611 			dev_warn(dev, "Found button without gpios\n");
612 			continue;
613 		}
614 
615 		gpio = of_get_gpio_flags(pp, 0, &flags);
616 		if (gpio < 0) {
617 			error = gpio;
618 			if (error != -EPROBE_DEFER)
619 				dev_err(dev,
620 					"Failed to get gpio flags, error: %d\n",
621 					error);
622 			goto err_free_pdata;
623 		}
624 
625 		button = &pdata->buttons[i++];
626 
627 		button->gpio = gpio;
628 		button->active_low = flags & OF_GPIO_ACTIVE_LOW;
629 
630 		if (of_property_read_u32(pp, "linux,code", &button->code)) {
631 			dev_err(dev, "Button without keycode: 0x%x\n",
632 				button->gpio);
633 			error = -EINVAL;
634 			goto err_free_pdata;
635 		}
636 
637 		button->desc = of_get_property(pp, "label", NULL);
638 
639 		if (of_property_read_u32(pp, "linux,input-type", &button->type))
640 			button->type = EV_KEY;
641 
642 		button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
643 
644 		if (of_property_read_u32(pp, "debounce-interval",
645 					 &button->debounce_interval))
646 			button->debounce_interval = 5;
647 	}
648 
649 	if (pdata->nbuttons == 0) {
650 		error = -EINVAL;
651 		goto err_free_pdata;
652 	}
653 
654 	return pdata;
655 
656 err_free_pdata:
657 	kfree(pdata);
658 err_out:
659 	return ERR_PTR(error);
660 }
661 
662 static struct of_device_id gpio_keys_of_match[] = {
663 	{ .compatible = "gpio-keys", },
664 	{ },
665 };
666 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
667 
668 #else
669 
670 static inline struct gpio_keys_platform_data *
671 gpio_keys_get_devtree_pdata(struct device *dev)
672 {
673 	return ERR_PTR(-ENODEV);
674 }
675 
676 #endif
677 
678 static void gpio_remove_key(struct gpio_button_data *bdata)
679 {
680 	free_irq(bdata->irq, bdata);
681 	if (bdata->timer_debounce)
682 		del_timer_sync(&bdata->timer);
683 	cancel_work_sync(&bdata->work);
684 	if (gpio_is_valid(bdata->button->gpio))
685 		gpio_free(bdata->button->gpio);
686 }
687 
688 static int gpio_keys_probe(struct platform_device *pdev)
689 {
690 	struct device *dev = &pdev->dev;
691 	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
692 	struct gpio_keys_drvdata *ddata;
693 	struct input_dev *input;
694 	int i, error;
695 	int wakeup = 0;
696 
697 	if (!pdata) {
698 		pdata = gpio_keys_get_devtree_pdata(dev);
699 		if (IS_ERR(pdata))
700 			return PTR_ERR(pdata);
701 	}
702 
703 	ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
704 			pdata->nbuttons * sizeof(struct gpio_button_data),
705 			GFP_KERNEL);
706 	input = input_allocate_device();
707 	if (!ddata || !input) {
708 		dev_err(dev, "failed to allocate state\n");
709 		error = -ENOMEM;
710 		goto fail1;
711 	}
712 
713 	ddata->pdata = pdata;
714 	ddata->input = input;
715 	mutex_init(&ddata->disable_lock);
716 
717 	platform_set_drvdata(pdev, ddata);
718 	input_set_drvdata(input, ddata);
719 
720 	input->name = pdata->name ? : pdev->name;
721 	input->phys = "gpio-keys/input0";
722 	input->dev.parent = &pdev->dev;
723 	input->open = gpio_keys_open;
724 	input->close = gpio_keys_close;
725 
726 	input->id.bustype = BUS_HOST;
727 	input->id.vendor = 0x0001;
728 	input->id.product = 0x0001;
729 	input->id.version = 0x0100;
730 
731 	/* Enable auto repeat feature of Linux input subsystem */
732 	if (pdata->rep)
733 		__set_bit(EV_REP, input->evbit);
734 
735 	for (i = 0; i < pdata->nbuttons; i++) {
736 		const struct gpio_keys_button *button = &pdata->buttons[i];
737 		struct gpio_button_data *bdata = &ddata->data[i];
738 
739 		error = gpio_keys_setup_key(pdev, input, bdata, button);
740 		if (error)
741 			goto fail2;
742 
743 		if (button->wakeup)
744 			wakeup = 1;
745 	}
746 
747 	error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
748 	if (error) {
749 		dev_err(dev, "Unable to export keys/switches, error: %d\n",
750 			error);
751 		goto fail2;
752 	}
753 
754 	error = input_register_device(input);
755 	if (error) {
756 		dev_err(dev, "Unable to register input device, error: %d\n",
757 			error);
758 		goto fail3;
759 	}
760 
761 	device_init_wakeup(&pdev->dev, wakeup);
762 
763 	return 0;
764 
765  fail3:
766 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
767  fail2:
768 	while (--i >= 0)
769 		gpio_remove_key(&ddata->data[i]);
770 
771  fail1:
772 	input_free_device(input);
773 	kfree(ddata);
774 	/* If we have no platform data, we allocated pdata dynamically. */
775 	if (!dev_get_platdata(&pdev->dev))
776 		kfree(pdata);
777 
778 	return error;
779 }
780 
781 static int gpio_keys_remove(struct platform_device *pdev)
782 {
783 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
784 	struct input_dev *input = ddata->input;
785 	int i;
786 
787 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
788 
789 	device_init_wakeup(&pdev->dev, 0);
790 
791 	for (i = 0; i < ddata->pdata->nbuttons; i++)
792 		gpio_remove_key(&ddata->data[i]);
793 
794 	input_unregister_device(input);
795 
796 	/* If we have no platform data, we allocated pdata dynamically. */
797 	if (!dev_get_platdata(&pdev->dev))
798 		kfree(ddata->pdata);
799 
800 	kfree(ddata);
801 
802 	return 0;
803 }
804 
805 #ifdef CONFIG_PM_SLEEP
806 static int gpio_keys_suspend(struct device *dev)
807 {
808 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
809 	struct input_dev *input = ddata->input;
810 	int i;
811 
812 	if (device_may_wakeup(dev)) {
813 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
814 			struct gpio_button_data *bdata = &ddata->data[i];
815 			if (bdata->button->wakeup)
816 				enable_irq_wake(bdata->irq);
817 		}
818 	} else {
819 		mutex_lock(&input->mutex);
820 		if (input->users)
821 			gpio_keys_close(input);
822 		mutex_unlock(&input->mutex);
823 	}
824 
825 	return 0;
826 }
827 
828 static int gpio_keys_resume(struct device *dev)
829 {
830 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
831 	struct input_dev *input = ddata->input;
832 	int error = 0;
833 	int i;
834 
835 	if (device_may_wakeup(dev)) {
836 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
837 			struct gpio_button_data *bdata = &ddata->data[i];
838 			if (bdata->button->wakeup)
839 				disable_irq_wake(bdata->irq);
840 		}
841 	} else {
842 		mutex_lock(&input->mutex);
843 		if (input->users)
844 			error = gpio_keys_open(input);
845 		mutex_unlock(&input->mutex);
846 	}
847 
848 	if (error)
849 		return error;
850 
851 	gpio_keys_report_state(ddata);
852 	return 0;
853 }
854 #endif
855 
856 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
857 
858 static struct platform_driver gpio_keys_device_driver = {
859 	.probe		= gpio_keys_probe,
860 	.remove		= gpio_keys_remove,
861 	.driver		= {
862 		.name	= "gpio-keys",
863 		.owner	= THIS_MODULE,
864 		.pm	= &gpio_keys_pm_ops,
865 		.of_match_table = of_match_ptr(gpio_keys_of_match),
866 	}
867 };
868 
869 static int __init gpio_keys_init(void)
870 {
871 	return platform_driver_register(&gpio_keys_device_driver);
872 }
873 
874 static void __exit gpio_keys_exit(void)
875 {
876 	platform_driver_unregister(&gpio_keys_device_driver);
877 }
878 
879 late_initcall(gpio_keys_init);
880 module_exit(gpio_keys_exit);
881 
882 MODULE_LICENSE("GPL");
883 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
884 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
885 MODULE_ALIAS("platform:gpio-keys");
886