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_platform.h>
30 #include <linux/of_gpio.h>
31 #include <linux/spinlock.h>
32 
33 struct gpio_button_data {
34 	const struct gpio_keys_button *button;
35 	struct input_dev *input;
36 	struct timer_list timer;
37 	struct work_struct work;
38 	unsigned int timer_debounce;	/* in msecs */
39 	unsigned int irq;
40 	spinlock_t lock;
41 	bool disabled;
42 	bool key_pressed;
43 };
44 
45 struct gpio_keys_drvdata {
46 	const struct gpio_keys_platform_data *pdata;
47 	struct input_dev *input;
48 	struct mutex disable_lock;
49 	struct gpio_button_data data[0];
50 };
51 
52 /*
53  * SYSFS interface for enabling/disabling keys and switches:
54  *
55  * There are 4 attributes under /sys/devices/platform/gpio-keys/
56  *	keys [ro]              - bitmap of keys (EV_KEY) which can be
57  *	                         disabled
58  *	switches [ro]          - bitmap of switches (EV_SW) which can be
59  *	                         disabled
60  *	disabled_keys [rw]     - bitmap of keys currently disabled
61  *	disabled_switches [rw] - bitmap of switches currently disabled
62  *
63  * Userland can change these values and hence disable event generation
64  * for each key (or switch). Disabling a key means its interrupt line
65  * is disabled.
66  *
67  * For example, if we have following switches set up as gpio-keys:
68  *	SW_DOCK = 5
69  *	SW_CAMERA_LENS_COVER = 9
70  *	SW_KEYPAD_SLIDE = 10
71  *	SW_FRONT_PROXIMITY = 11
72  * This is read from switches:
73  *	11-9,5
74  * Next we want to disable proximity (11) and dock (5), we write:
75  *	11,5
76  * to file disabled_switches. Now proximity and dock IRQs are disabled.
77  * This can be verified by reading the file disabled_switches:
78  *	11,5
79  * If we now want to enable proximity (11) switch we write:
80  *	5
81  * to disabled_switches.
82  *
83  * We can disable only those keys which don't allow sharing the irq.
84  */
85 
86 /**
87  * get_n_events_by_type() - returns maximum number of events per @type
88  * @type: type of button (%EV_KEY, %EV_SW)
89  *
90  * Return value of this function can be used to allocate bitmap
91  * large enough to hold all bits for given type.
92  */
93 static inline int get_n_events_by_type(int type)
94 {
95 	BUG_ON(type != EV_SW && type != EV_KEY);
96 
97 	return (type == EV_KEY) ? KEY_CNT : SW_CNT;
98 }
99 
100 /**
101  * gpio_keys_disable_button() - disables given GPIO button
102  * @bdata: button data for button to be disabled
103  *
104  * Disables button pointed by @bdata. This is done by masking
105  * IRQ line. After this function is called, button won't generate
106  * input events anymore. Note that one can only disable buttons
107  * that don't share IRQs.
108  *
109  * Make sure that @bdata->disable_lock is locked when entering
110  * this function to avoid races when concurrent threads are
111  * disabling buttons at the same time.
112  */
113 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
114 {
115 	if (!bdata->disabled) {
116 		/*
117 		 * Disable IRQ and possible debouncing timer.
118 		 */
119 		disable_irq(bdata->irq);
120 		if (bdata->timer_debounce)
121 			del_timer_sync(&bdata->timer);
122 
123 		bdata->disabled = true;
124 	}
125 }
126 
127 /**
128  * gpio_keys_enable_button() - enables given GPIO button
129  * @bdata: button data for button to be disabled
130  *
131  * Enables given button pointed by @bdata.
132  *
133  * Make sure that @bdata->disable_lock is locked when entering
134  * this function to avoid races with concurrent threads trying
135  * to enable the same button at the same time.
136  */
137 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
138 {
139 	if (bdata->disabled) {
140 		enable_irq(bdata->irq);
141 		bdata->disabled = false;
142 	}
143 }
144 
145 /**
146  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
147  * @ddata: pointer to drvdata
148  * @buf: buffer where stringified bitmap is written
149  * @type: button type (%EV_KEY, %EV_SW)
150  * @only_disabled: does caller want only those buttons that are
151  *                 currently disabled or all buttons that can be
152  *                 disabled
153  *
154  * This function writes buttons that can be disabled to @buf. If
155  * @only_disabled is true, then @buf contains only those buttons
156  * that are currently disabled. Returns 0 on success or negative
157  * errno on failure.
158  */
159 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
160 					  char *buf, unsigned int type,
161 					  bool only_disabled)
162 {
163 	int n_events = get_n_events_by_type(type);
164 	unsigned long *bits;
165 	ssize_t ret;
166 	int i;
167 
168 	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
169 	if (!bits)
170 		return -ENOMEM;
171 
172 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
173 		struct gpio_button_data *bdata = &ddata->data[i];
174 
175 		if (bdata->button->type != type)
176 			continue;
177 
178 		if (only_disabled && !bdata->disabled)
179 			continue;
180 
181 		__set_bit(bdata->button->code, bits);
182 	}
183 
184 	ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
185 	buf[ret++] = '\n';
186 	buf[ret] = '\0';
187 
188 	kfree(bits);
189 
190 	return ret;
191 }
192 
193 /**
194  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
195  * @ddata: pointer to drvdata
196  * @buf: buffer from userspace that contains stringified bitmap
197  * @type: button type (%EV_KEY, %EV_SW)
198  *
199  * This function parses stringified bitmap from @buf and disables/enables
200  * GPIO buttons accordingly. Returns 0 on success and negative error
201  * on failure.
202  */
203 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
204 					   const char *buf, unsigned int type)
205 {
206 	int n_events = get_n_events_by_type(type);
207 	unsigned long *bits;
208 	ssize_t error;
209 	int i;
210 
211 	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
212 	if (!bits)
213 		return -ENOMEM;
214 
215 	error = bitmap_parselist(buf, bits, n_events);
216 	if (error)
217 		goto out;
218 
219 	/* First validate */
220 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
221 		struct gpio_button_data *bdata = &ddata->data[i];
222 
223 		if (bdata->button->type != type)
224 			continue;
225 
226 		if (test_bit(bdata->button->code, bits) &&
227 		    !bdata->button->can_disable) {
228 			error = -EINVAL;
229 			goto out;
230 		}
231 	}
232 
233 	mutex_lock(&ddata->disable_lock);
234 
235 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
236 		struct gpio_button_data *bdata = &ddata->data[i];
237 
238 		if (bdata->button->type != type)
239 			continue;
240 
241 		if (test_bit(bdata->button->code, bits))
242 			gpio_keys_disable_button(bdata);
243 		else
244 			gpio_keys_enable_button(bdata);
245 	}
246 
247 	mutex_unlock(&ddata->disable_lock);
248 
249 out:
250 	kfree(bits);
251 	return error;
252 }
253 
254 #define ATTR_SHOW_FN(name, type, only_disabled)				\
255 static ssize_t gpio_keys_show_##name(struct device *dev,		\
256 				     struct device_attribute *attr,	\
257 				     char *buf)				\
258 {									\
259 	struct platform_device *pdev = to_platform_device(dev);		\
260 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
261 									\
262 	return gpio_keys_attr_show_helper(ddata, buf,			\
263 					  type, only_disabled);		\
264 }
265 
266 ATTR_SHOW_FN(keys, EV_KEY, false);
267 ATTR_SHOW_FN(switches, EV_SW, false);
268 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
269 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
270 
271 /*
272  * ATTRIBUTES:
273  *
274  * /sys/devices/platform/gpio-keys/keys [ro]
275  * /sys/devices/platform/gpio-keys/switches [ro]
276  */
277 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
278 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
279 
280 #define ATTR_STORE_FN(name, type)					\
281 static ssize_t gpio_keys_store_##name(struct device *dev,		\
282 				      struct device_attribute *attr,	\
283 				      const char *buf,			\
284 				      size_t count)			\
285 {									\
286 	struct platform_device *pdev = to_platform_device(dev);		\
287 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
288 	ssize_t error;							\
289 									\
290 	error = gpio_keys_attr_store_helper(ddata, buf, type);		\
291 	if (error)							\
292 		return error;						\
293 									\
294 	return count;							\
295 }
296 
297 ATTR_STORE_FN(disabled_keys, EV_KEY);
298 ATTR_STORE_FN(disabled_switches, EV_SW);
299 
300 /*
301  * ATTRIBUTES:
302  *
303  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
304  * /sys/devices/platform/gpio-keys/disables_switches [rw]
305  */
306 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
307 		   gpio_keys_show_disabled_keys,
308 		   gpio_keys_store_disabled_keys);
309 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
310 		   gpio_keys_show_disabled_switches,
311 		   gpio_keys_store_disabled_switches);
312 
313 static struct attribute *gpio_keys_attrs[] = {
314 	&dev_attr_keys.attr,
315 	&dev_attr_switches.attr,
316 	&dev_attr_disabled_keys.attr,
317 	&dev_attr_disabled_switches.attr,
318 	NULL,
319 };
320 
321 static struct attribute_group gpio_keys_attr_group = {
322 	.attrs = gpio_keys_attrs,
323 };
324 
325 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
326 {
327 	const struct gpio_keys_button *button = bdata->button;
328 	struct input_dev *input = bdata->input;
329 	unsigned int type = button->type ?: EV_KEY;
330 	int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
331 
332 	if (type == EV_ABS) {
333 		if (state)
334 			input_event(input, type, button->code, button->value);
335 	} else {
336 		input_event(input, type, button->code, !!state);
337 	}
338 	input_sync(input);
339 }
340 
341 static void gpio_keys_gpio_work_func(struct work_struct *work)
342 {
343 	struct gpio_button_data *bdata =
344 		container_of(work, struct gpio_button_data, work);
345 
346 	gpio_keys_gpio_report_event(bdata);
347 
348 	if (bdata->button->wakeup)
349 		pm_relax(bdata->input->dev.parent);
350 }
351 
352 static void gpio_keys_gpio_timer(unsigned long _data)
353 {
354 	struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
355 
356 	schedule_work(&bdata->work);
357 }
358 
359 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
360 {
361 	struct gpio_button_data *bdata = dev_id;
362 
363 	BUG_ON(irq != bdata->irq);
364 
365 	if (bdata->button->wakeup)
366 		pm_stay_awake(bdata->input->dev.parent);
367 	if (bdata->timer_debounce)
368 		mod_timer(&bdata->timer,
369 			jiffies + msecs_to_jiffies(bdata->timer_debounce));
370 	else
371 		schedule_work(&bdata->work);
372 
373 	return IRQ_HANDLED;
374 }
375 
376 static void gpio_keys_irq_timer(unsigned long _data)
377 {
378 	struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
379 	struct input_dev *input = bdata->input;
380 	unsigned long flags;
381 
382 	spin_lock_irqsave(&bdata->lock, flags);
383 	if (bdata->key_pressed) {
384 		input_event(input, EV_KEY, bdata->button->code, 0);
385 		input_sync(input);
386 		bdata->key_pressed = false;
387 	}
388 	spin_unlock_irqrestore(&bdata->lock, flags);
389 }
390 
391 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
392 {
393 	struct gpio_button_data *bdata = dev_id;
394 	const struct gpio_keys_button *button = bdata->button;
395 	struct input_dev *input = bdata->input;
396 	unsigned long flags;
397 
398 	BUG_ON(irq != bdata->irq);
399 
400 	spin_lock_irqsave(&bdata->lock, flags);
401 
402 	if (!bdata->key_pressed) {
403 		if (bdata->button->wakeup)
404 			pm_wakeup_event(bdata->input->dev.parent, 0);
405 
406 		input_event(input, EV_KEY, button->code, 1);
407 		input_sync(input);
408 
409 		if (!bdata->timer_debounce) {
410 			input_event(input, EV_KEY, button->code, 0);
411 			input_sync(input);
412 			goto out;
413 		}
414 
415 		bdata->key_pressed = true;
416 	}
417 
418 	if (bdata->timer_debounce)
419 		mod_timer(&bdata->timer,
420 			jiffies + msecs_to_jiffies(bdata->timer_debounce));
421 out:
422 	spin_unlock_irqrestore(&bdata->lock, flags);
423 	return IRQ_HANDLED;
424 }
425 
426 static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
427 					 struct input_dev *input,
428 					 struct gpio_button_data *bdata,
429 					 const struct gpio_keys_button *button)
430 {
431 	const char *desc = button->desc ? button->desc : "gpio_keys";
432 	struct device *dev = &pdev->dev;
433 	irq_handler_t isr;
434 	unsigned long irqflags;
435 	int irq, error;
436 
437 	bdata->input = input;
438 	bdata->button = button;
439 	spin_lock_init(&bdata->lock);
440 
441 	if (gpio_is_valid(button->gpio)) {
442 
443 		error = gpio_request(button->gpio, desc);
444 		if (error < 0) {
445 			dev_err(dev, "Failed to request GPIO %d, error %d\n",
446 				button->gpio, error);
447 			return error;
448 		}
449 
450 		error = gpio_direction_input(button->gpio);
451 		if (error < 0) {
452 			dev_err(dev,
453 				"Failed to configure direction for GPIO %d, error %d\n",
454 				button->gpio, error);
455 			goto fail;
456 		}
457 
458 		if (button->debounce_interval) {
459 			error = gpio_set_debounce(button->gpio,
460 					button->debounce_interval * 1000);
461 			/* use timer if gpiolib doesn't provide debounce */
462 			if (error < 0)
463 				bdata->timer_debounce =
464 						button->debounce_interval;
465 		}
466 
467 		irq = gpio_to_irq(button->gpio);
468 		if (irq < 0) {
469 			error = irq;
470 			dev_err(dev,
471 				"Unable to get irq number for GPIO %d, error %d\n",
472 				button->gpio, error);
473 			goto fail;
474 		}
475 		bdata->irq = irq;
476 
477 		INIT_WORK(&bdata->work, gpio_keys_gpio_work_func);
478 		setup_timer(&bdata->timer,
479 			    gpio_keys_gpio_timer, (unsigned long)bdata);
480 
481 		isr = gpio_keys_gpio_isr;
482 		irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
483 
484 	} else {
485 		if (!button->irq) {
486 			dev_err(dev, "No IRQ specified\n");
487 			return -EINVAL;
488 		}
489 		bdata->irq = button->irq;
490 
491 		if (button->type && button->type != EV_KEY) {
492 			dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
493 			return -EINVAL;
494 		}
495 
496 		bdata->timer_debounce = button->debounce_interval;
497 		setup_timer(&bdata->timer,
498 			    gpio_keys_irq_timer, (unsigned long)bdata);
499 
500 		isr = gpio_keys_irq_isr;
501 		irqflags = 0;
502 	}
503 
504 	input_set_capability(input, button->type ?: EV_KEY, button->code);
505 
506 	/*
507 	 * If platform has specified that the button can be disabled,
508 	 * we don't want it to share the interrupt line.
509 	 */
510 	if (!button->can_disable)
511 		irqflags |= IRQF_SHARED;
512 
513 	error = request_any_context_irq(bdata->irq, isr, irqflags, desc, bdata);
514 	if (error < 0) {
515 		dev_err(dev, "Unable to claim irq %d; error %d\n",
516 			bdata->irq, error);
517 		goto fail;
518 	}
519 
520 	return 0;
521 
522 fail:
523 	if (gpio_is_valid(button->gpio))
524 		gpio_free(button->gpio);
525 
526 	return error;
527 }
528 
529 static int gpio_keys_open(struct input_dev *input)
530 {
531 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
532 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
533 
534 	return pdata->enable ? pdata->enable(input->dev.parent) : 0;
535 }
536 
537 static void gpio_keys_close(struct input_dev *input)
538 {
539 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
540 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
541 
542 	if (pdata->disable)
543 		pdata->disable(input->dev.parent);
544 }
545 
546 /*
547  * Handlers for alternative sources of platform_data
548  */
549 
550 #ifdef CONFIG_OF
551 /*
552  * Translate OpenFirmware node properties into platform_data
553  */
554 static struct gpio_keys_platform_data * __devinit
555 gpio_keys_get_devtree_pdata(struct device *dev)
556 {
557 	struct device_node *node, *pp;
558 	struct gpio_keys_platform_data *pdata;
559 	struct gpio_keys_button *button;
560 	int error;
561 	int nbuttons;
562 	int i;
563 
564 	node = dev->of_node;
565 	if (!node) {
566 		error = -ENODEV;
567 		goto err_out;
568 	}
569 
570 	nbuttons = of_get_child_count(node);
571 	if (nbuttons == 0) {
572 		error = -ENODEV;
573 		goto err_out;
574 	}
575 
576 	pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
577 			GFP_KERNEL);
578 	if (!pdata) {
579 		error = -ENOMEM;
580 		goto err_out;
581 	}
582 
583 	pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
584 	pdata->nbuttons = nbuttons;
585 
586 	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
587 
588 	i = 0;
589 	for_each_child_of_node(node, pp) {
590 		enum of_gpio_flags flags;
591 
592 		if (!of_find_property(pp, "gpios", NULL)) {
593 			pdata->nbuttons--;
594 			dev_warn(dev, "Found button without gpios\n");
595 			continue;
596 		}
597 
598 		button = &pdata->buttons[i++];
599 
600 		button->gpio = of_get_gpio_flags(pp, 0, &flags);
601 		button->active_low = flags & OF_GPIO_ACTIVE_LOW;
602 
603 		if (of_property_read_u32(pp, "linux,code", &button->code)) {
604 			dev_err(dev, "Button without keycode: 0x%x\n",
605 				button->gpio);
606 			error = -EINVAL;
607 			goto err_free_pdata;
608 		}
609 
610 		button->desc = of_get_property(pp, "label", NULL);
611 
612 		if (of_property_read_u32(pp, "linux,input-type", &button->type))
613 			button->type = EV_KEY;
614 
615 		button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
616 
617 		if (of_property_read_u32(pp, "debounce-interval",
618 					 &button->debounce_interval))
619 			button->debounce_interval = 5;
620 	}
621 
622 	if (pdata->nbuttons == 0) {
623 		error = -EINVAL;
624 		goto err_free_pdata;
625 	}
626 
627 	return pdata;
628 
629 err_free_pdata:
630 	kfree(pdata);
631 err_out:
632 	return ERR_PTR(error);
633 }
634 
635 static struct of_device_id gpio_keys_of_match[] = {
636 	{ .compatible = "gpio-keys", },
637 	{ },
638 };
639 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
640 
641 #else
642 
643 static inline struct gpio_keys_platform_data *
644 gpio_keys_get_devtree_pdata(struct device *dev)
645 {
646 	return ERR_PTR(-ENODEV);
647 }
648 
649 #endif
650 
651 static void gpio_remove_key(struct gpio_button_data *bdata)
652 {
653 	free_irq(bdata->irq, bdata);
654 	if (bdata->timer_debounce)
655 		del_timer_sync(&bdata->timer);
656 	cancel_work_sync(&bdata->work);
657 	if (gpio_is_valid(bdata->button->gpio))
658 		gpio_free(bdata->button->gpio);
659 }
660 
661 static int __devinit gpio_keys_probe(struct platform_device *pdev)
662 {
663 	struct device *dev = &pdev->dev;
664 	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
665 	struct gpio_keys_drvdata *ddata;
666 	struct input_dev *input;
667 	int i, error;
668 	int wakeup = 0;
669 
670 	if (!pdata) {
671 		pdata = gpio_keys_get_devtree_pdata(dev);
672 		if (IS_ERR(pdata))
673 			return PTR_ERR(pdata);
674 	}
675 
676 	ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
677 			pdata->nbuttons * sizeof(struct gpio_button_data),
678 			GFP_KERNEL);
679 	input = input_allocate_device();
680 	if (!ddata || !input) {
681 		dev_err(dev, "failed to allocate state\n");
682 		error = -ENOMEM;
683 		goto fail1;
684 	}
685 
686 	ddata->pdata = pdata;
687 	ddata->input = input;
688 	mutex_init(&ddata->disable_lock);
689 
690 	platform_set_drvdata(pdev, ddata);
691 	input_set_drvdata(input, ddata);
692 
693 	input->name = pdata->name ? : pdev->name;
694 	input->phys = "gpio-keys/input0";
695 	input->dev.parent = &pdev->dev;
696 	input->open = gpio_keys_open;
697 	input->close = gpio_keys_close;
698 
699 	input->id.bustype = BUS_HOST;
700 	input->id.vendor = 0x0001;
701 	input->id.product = 0x0001;
702 	input->id.version = 0x0100;
703 
704 	/* Enable auto repeat feature of Linux input subsystem */
705 	if (pdata->rep)
706 		__set_bit(EV_REP, input->evbit);
707 
708 	for (i = 0; i < pdata->nbuttons; i++) {
709 		const struct gpio_keys_button *button = &pdata->buttons[i];
710 		struct gpio_button_data *bdata = &ddata->data[i];
711 
712 		error = gpio_keys_setup_key(pdev, input, bdata, button);
713 		if (error)
714 			goto fail2;
715 
716 		if (button->wakeup)
717 			wakeup = 1;
718 	}
719 
720 	error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
721 	if (error) {
722 		dev_err(dev, "Unable to export keys/switches, error: %d\n",
723 			error);
724 		goto fail2;
725 	}
726 
727 	error = input_register_device(input);
728 	if (error) {
729 		dev_err(dev, "Unable to register input device, error: %d\n",
730 			error);
731 		goto fail3;
732 	}
733 
734 	/* get current state of buttons that are connected to GPIOs */
735 	for (i = 0; i < pdata->nbuttons; i++) {
736 		struct gpio_button_data *bdata = &ddata->data[i];
737 		if (gpio_is_valid(bdata->button->gpio))
738 			gpio_keys_gpio_report_event(bdata);
739 	}
740 	input_sync(input);
741 
742 	device_init_wakeup(&pdev->dev, wakeup);
743 
744 	return 0;
745 
746  fail3:
747 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
748  fail2:
749 	while (--i >= 0)
750 		gpio_remove_key(&ddata->data[i]);
751 
752 	platform_set_drvdata(pdev, NULL);
753  fail1:
754 	input_free_device(input);
755 	kfree(ddata);
756 	/* If we have no platform data, we allocated pdata dynamically. */
757 	if (!dev_get_platdata(&pdev->dev))
758 		kfree(pdata);
759 
760 	return error;
761 }
762 
763 static int __devexit gpio_keys_remove(struct platform_device *pdev)
764 {
765 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
766 	struct input_dev *input = ddata->input;
767 	int i;
768 
769 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
770 
771 	device_init_wakeup(&pdev->dev, 0);
772 
773 	for (i = 0; i < ddata->pdata->nbuttons; i++)
774 		gpio_remove_key(&ddata->data[i]);
775 
776 	input_unregister_device(input);
777 
778 	/* If we have no platform data, we allocated pdata dynamically. */
779 	if (!dev_get_platdata(&pdev->dev))
780 		kfree(ddata->pdata);
781 
782 	kfree(ddata);
783 
784 	return 0;
785 }
786 
787 #ifdef CONFIG_PM_SLEEP
788 static int gpio_keys_suspend(struct device *dev)
789 {
790 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
791 	int i;
792 
793 	if (device_may_wakeup(dev)) {
794 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
795 			struct gpio_button_data *bdata = &ddata->data[i];
796 			if (bdata->button->wakeup)
797 				enable_irq_wake(bdata->irq);
798 		}
799 	}
800 
801 	return 0;
802 }
803 
804 static int gpio_keys_resume(struct device *dev)
805 {
806 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
807 	int i;
808 
809 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
810 		struct gpio_button_data *bdata = &ddata->data[i];
811 		if (bdata->button->wakeup && device_may_wakeup(dev))
812 			disable_irq_wake(bdata->irq);
813 
814 		if (gpio_is_valid(bdata->button->gpio))
815 			gpio_keys_gpio_report_event(bdata);
816 	}
817 	input_sync(ddata->input);
818 
819 	return 0;
820 }
821 #endif
822 
823 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
824 
825 static struct platform_driver gpio_keys_device_driver = {
826 	.probe		= gpio_keys_probe,
827 	.remove		= __devexit_p(gpio_keys_remove),
828 	.driver		= {
829 		.name	= "gpio-keys",
830 		.owner	= THIS_MODULE,
831 		.pm	= &gpio_keys_pm_ops,
832 		.of_match_table = of_match_ptr(gpio_keys_of_match),
833 	}
834 };
835 
836 static int __init gpio_keys_init(void)
837 {
838 	return platform_driver_register(&gpio_keys_device_driver);
839 }
840 
841 static void __exit gpio_keys_exit(void)
842 {
843 	platform_driver_unregister(&gpio_keys_device_driver);
844 }
845 
846 late_initcall(gpio_keys_init);
847 module_exit(gpio_keys_exit);
848 
849 MODULE_LICENSE("GPL");
850 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
851 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
852 MODULE_ALIAS("platform:gpio-keys");
853