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 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  * get_bm_events_by_type() - returns bitmap of supported events per @type
108  * @input: input device from which bitmap is retrieved
109  * @type: type of button (%EV_KEY, %EV_SW)
110  *
111  * Return value of this function can be used to allocate bitmap
112  * large enough to hold all bits for given type.
113  */
114 static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
115 						  int type)
116 {
117 	BUG_ON(type != EV_SW && type != EV_KEY);
118 
119 	return (type == EV_KEY) ? dev->keybit : dev->swbit;
120 }
121 
122 /**
123  * gpio_keys_disable_button() - disables given GPIO button
124  * @bdata: button data for button to be disabled
125  *
126  * Disables button pointed by @bdata. This is done by masking
127  * IRQ line. After this function is called, button won't generate
128  * input events anymore. Note that one can only disable buttons
129  * that don't share IRQs.
130  *
131  * Make sure that @bdata->disable_lock is locked when entering
132  * this function to avoid races when concurrent threads are
133  * disabling buttons at the same time.
134  */
135 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
136 {
137 	if (!bdata->disabled) {
138 		/*
139 		 * Disable IRQ and associated timer/work structure.
140 		 */
141 		disable_irq(bdata->irq);
142 
143 		if (gpio_is_valid(bdata->button->gpio))
144 			cancel_delayed_work_sync(&bdata->work);
145 		else
146 			del_timer_sync(&bdata->release_timer);
147 
148 		bdata->disabled = true;
149 	}
150 }
151 
152 /**
153  * gpio_keys_enable_button() - enables given GPIO button
154  * @bdata: button data for button to be disabled
155  *
156  * Enables given button pointed by @bdata.
157  *
158  * Make sure that @bdata->disable_lock is locked when entering
159  * this function to avoid races with concurrent threads trying
160  * to enable the same button at the same time.
161  */
162 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
163 {
164 	if (bdata->disabled) {
165 		enable_irq(bdata->irq);
166 		bdata->disabled = false;
167 	}
168 }
169 
170 /**
171  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
172  * @ddata: pointer to drvdata
173  * @buf: buffer where stringified bitmap is written
174  * @type: button type (%EV_KEY, %EV_SW)
175  * @only_disabled: does caller want only those buttons that are
176  *                 currently disabled or all buttons that can be
177  *                 disabled
178  *
179  * This function writes buttons that can be disabled to @buf. If
180  * @only_disabled is true, then @buf contains only those buttons
181  * that are currently disabled. Returns 0 on success or negative
182  * errno on failure.
183  */
184 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
185 					  char *buf, unsigned int type,
186 					  bool only_disabled)
187 {
188 	int n_events = get_n_events_by_type(type);
189 	unsigned long *bits;
190 	ssize_t ret;
191 	int i;
192 
193 	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
194 	if (!bits)
195 		return -ENOMEM;
196 
197 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
198 		struct gpio_button_data *bdata = &ddata->data[i];
199 
200 		if (bdata->button->type != type)
201 			continue;
202 
203 		if (only_disabled && !bdata->disabled)
204 			continue;
205 
206 		__set_bit(bdata->button->code, bits);
207 	}
208 
209 	ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
210 	buf[ret++] = '\n';
211 	buf[ret] = '\0';
212 
213 	kfree(bits);
214 
215 	return ret;
216 }
217 
218 /**
219  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
220  * @ddata: pointer to drvdata
221  * @buf: buffer from userspace that contains stringified bitmap
222  * @type: button type (%EV_KEY, %EV_SW)
223  *
224  * This function parses stringified bitmap from @buf and disables/enables
225  * GPIO buttons accordingly. Returns 0 on success and negative error
226  * on failure.
227  */
228 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
229 					   const char *buf, unsigned int type)
230 {
231 	int n_events = get_n_events_by_type(type);
232 	const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
233 	unsigned long *bits;
234 	ssize_t error;
235 	int i;
236 
237 	bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
238 	if (!bits)
239 		return -ENOMEM;
240 
241 	error = bitmap_parselist(buf, bits, n_events);
242 	if (error)
243 		goto out;
244 
245 	/* First validate */
246 	if (!bitmap_subset(bits, bitmap, n_events)) {
247 		error = -EINVAL;
248 		goto out;
249 	}
250 
251 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
252 		struct gpio_button_data *bdata = &ddata->data[i];
253 
254 		if (bdata->button->type != type)
255 			continue;
256 
257 		if (test_bit(bdata->button->code, bits) &&
258 		    !bdata->button->can_disable) {
259 			error = -EINVAL;
260 			goto out;
261 		}
262 	}
263 
264 	mutex_lock(&ddata->disable_lock);
265 
266 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
267 		struct gpio_button_data *bdata = &ddata->data[i];
268 
269 		if (bdata->button->type != type)
270 			continue;
271 
272 		if (test_bit(bdata->button->code, bits))
273 			gpio_keys_disable_button(bdata);
274 		else
275 			gpio_keys_enable_button(bdata);
276 	}
277 
278 	mutex_unlock(&ddata->disable_lock);
279 
280 out:
281 	kfree(bits);
282 	return error;
283 }
284 
285 #define ATTR_SHOW_FN(name, type, only_disabled)				\
286 static ssize_t gpio_keys_show_##name(struct device *dev,		\
287 				     struct device_attribute *attr,	\
288 				     char *buf)				\
289 {									\
290 	struct platform_device *pdev = to_platform_device(dev);		\
291 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
292 									\
293 	return gpio_keys_attr_show_helper(ddata, buf,			\
294 					  type, only_disabled);		\
295 }
296 
297 ATTR_SHOW_FN(keys, EV_KEY, false);
298 ATTR_SHOW_FN(switches, EV_SW, false);
299 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
300 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
301 
302 /*
303  * ATTRIBUTES:
304  *
305  * /sys/devices/platform/gpio-keys/keys [ro]
306  * /sys/devices/platform/gpio-keys/switches [ro]
307  */
308 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
309 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
310 
311 #define ATTR_STORE_FN(name, type)					\
312 static ssize_t gpio_keys_store_##name(struct device *dev,		\
313 				      struct device_attribute *attr,	\
314 				      const char *buf,			\
315 				      size_t count)			\
316 {									\
317 	struct platform_device *pdev = to_platform_device(dev);		\
318 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
319 	ssize_t error;							\
320 									\
321 	error = gpio_keys_attr_store_helper(ddata, buf, type);		\
322 	if (error)							\
323 		return error;						\
324 									\
325 	return count;							\
326 }
327 
328 ATTR_STORE_FN(disabled_keys, EV_KEY);
329 ATTR_STORE_FN(disabled_switches, EV_SW);
330 
331 /*
332  * ATTRIBUTES:
333  *
334  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
335  * /sys/devices/platform/gpio-keys/disables_switches [rw]
336  */
337 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
338 		   gpio_keys_show_disabled_keys,
339 		   gpio_keys_store_disabled_keys);
340 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
341 		   gpio_keys_show_disabled_switches,
342 		   gpio_keys_store_disabled_switches);
343 
344 static struct attribute *gpio_keys_attrs[] = {
345 	&dev_attr_keys.attr,
346 	&dev_attr_switches.attr,
347 	&dev_attr_disabled_keys.attr,
348 	&dev_attr_disabled_switches.attr,
349 	NULL,
350 };
351 
352 static struct attribute_group gpio_keys_attr_group = {
353 	.attrs = gpio_keys_attrs,
354 };
355 
356 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
357 {
358 	const struct gpio_keys_button *button = bdata->button;
359 	struct input_dev *input = bdata->input;
360 	unsigned int type = button->type ?: EV_KEY;
361 	int state = gpio_get_value_cansleep(button->gpio);
362 
363 	if (state < 0) {
364 		dev_err(input->dev.parent, "failed to get gpio state\n");
365 		return;
366 	}
367 
368 	state = (state ? 1 : 0) ^ button->active_low;
369 	if (type == EV_ABS) {
370 		if (state)
371 			input_event(input, type, button->code, button->value);
372 	} else {
373 		input_event(input, type, button->code, !!state);
374 	}
375 	input_sync(input);
376 }
377 
378 static void gpio_keys_gpio_work_func(struct work_struct *work)
379 {
380 	struct gpio_button_data *bdata =
381 		container_of(work, struct gpio_button_data, work.work);
382 
383 	gpio_keys_gpio_report_event(bdata);
384 
385 	if (bdata->button->wakeup)
386 		pm_relax(bdata->input->dev.parent);
387 }
388 
389 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
390 {
391 	struct gpio_button_data *bdata = dev_id;
392 
393 	BUG_ON(irq != bdata->irq);
394 
395 	if (bdata->button->wakeup)
396 		pm_stay_awake(bdata->input->dev.parent);
397 
398 	mod_delayed_work(system_wq,
399 			 &bdata->work,
400 			 msecs_to_jiffies(bdata->software_debounce));
401 
402 	return IRQ_HANDLED;
403 }
404 
405 static void gpio_keys_irq_timer(unsigned long _data)
406 {
407 	struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
408 	struct input_dev *input = bdata->input;
409 	unsigned long flags;
410 
411 	spin_lock_irqsave(&bdata->lock, flags);
412 	if (bdata->key_pressed) {
413 		input_event(input, EV_KEY, bdata->button->code, 0);
414 		input_sync(input);
415 		bdata->key_pressed = false;
416 	}
417 	spin_unlock_irqrestore(&bdata->lock, flags);
418 }
419 
420 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
421 {
422 	struct gpio_button_data *bdata = dev_id;
423 	const struct gpio_keys_button *button = bdata->button;
424 	struct input_dev *input = bdata->input;
425 	unsigned long flags;
426 
427 	BUG_ON(irq != bdata->irq);
428 
429 	spin_lock_irqsave(&bdata->lock, flags);
430 
431 	if (!bdata->key_pressed) {
432 		if (bdata->button->wakeup)
433 			pm_wakeup_event(bdata->input->dev.parent, 0);
434 
435 		input_event(input, EV_KEY, button->code, 1);
436 		input_sync(input);
437 
438 		if (!bdata->release_delay) {
439 			input_event(input, EV_KEY, button->code, 0);
440 			input_sync(input);
441 			goto out;
442 		}
443 
444 		bdata->key_pressed = true;
445 	}
446 
447 	if (bdata->release_delay)
448 		mod_timer(&bdata->release_timer,
449 			jiffies + msecs_to_jiffies(bdata->release_delay));
450 out:
451 	spin_unlock_irqrestore(&bdata->lock, flags);
452 	return IRQ_HANDLED;
453 }
454 
455 static void gpio_keys_quiesce_key(void *data)
456 {
457 	struct gpio_button_data *bdata = data;
458 
459 	if (gpio_is_valid(bdata->button->gpio))
460 		cancel_delayed_work_sync(&bdata->work);
461 	else
462 		del_timer_sync(&bdata->release_timer);
463 }
464 
465 static int gpio_keys_setup_key(struct platform_device *pdev,
466 				struct input_dev *input,
467 				struct gpio_button_data *bdata,
468 				const struct gpio_keys_button *button)
469 {
470 	const char *desc = button->desc ? button->desc : "gpio_keys";
471 	struct device *dev = &pdev->dev;
472 	irq_handler_t isr;
473 	unsigned long irqflags;
474 	int irq;
475 	int error;
476 
477 	bdata->input = input;
478 	bdata->button = button;
479 	spin_lock_init(&bdata->lock);
480 
481 	if (gpio_is_valid(button->gpio)) {
482 
483 		error = devm_gpio_request_one(&pdev->dev, button->gpio,
484 					      GPIOF_IN, desc);
485 		if (error < 0) {
486 			dev_err(dev, "Failed to request GPIO %d, error %d\n",
487 				button->gpio, error);
488 			return error;
489 		}
490 
491 		if (button->debounce_interval) {
492 			error = gpio_set_debounce(button->gpio,
493 					button->debounce_interval * 1000);
494 			/* use timer if gpiolib doesn't provide debounce */
495 			if (error < 0)
496 				bdata->software_debounce =
497 						button->debounce_interval;
498 		}
499 
500 		if (button->irq) {
501 			bdata->irq = button->irq;
502 		} else {
503 			irq = gpio_to_irq(button->gpio);
504 			if (irq < 0) {
505 				error = irq;
506 				dev_err(dev,
507 					"Unable to get irq number for GPIO %d, error %d\n",
508 					button->gpio, error);
509 				return error;
510 			}
511 			bdata->irq = irq;
512 		}
513 
514 		INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
515 
516 		isr = gpio_keys_gpio_isr;
517 		irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
518 
519 	} else {
520 		if (!button->irq) {
521 			dev_err(dev, "No IRQ specified\n");
522 			return -EINVAL;
523 		}
524 		bdata->irq = button->irq;
525 
526 		if (button->type && button->type != EV_KEY) {
527 			dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
528 			return -EINVAL;
529 		}
530 
531 		bdata->release_delay = button->debounce_interval;
532 		setup_timer(&bdata->release_timer,
533 			    gpio_keys_irq_timer, (unsigned long)bdata);
534 
535 		isr = gpio_keys_irq_isr;
536 		irqflags = 0;
537 	}
538 
539 	input_set_capability(input, button->type ?: EV_KEY, button->code);
540 
541 	/*
542 	 * Install custom action to cancel release timer and
543 	 * workqueue item.
544 	 */
545 	error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
546 	if (error) {
547 		dev_err(&pdev->dev,
548 			"failed to register quiesce action, error: %d\n",
549 			error);
550 		return error;
551 	}
552 
553 	/*
554 	 * If platform has specified that the button can be disabled,
555 	 * we don't want it to share the interrupt line.
556 	 */
557 	if (!button->can_disable)
558 		irqflags |= IRQF_SHARED;
559 
560 	error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
561 					     isr, irqflags, desc, bdata);
562 	if (error < 0) {
563 		dev_err(dev, "Unable to claim irq %d; error %d\n",
564 			bdata->irq, error);
565 		return error;
566 	}
567 
568 	return 0;
569 }
570 
571 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
572 {
573 	struct input_dev *input = ddata->input;
574 	int i;
575 
576 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
577 		struct gpio_button_data *bdata = &ddata->data[i];
578 		if (gpio_is_valid(bdata->button->gpio))
579 			gpio_keys_gpio_report_event(bdata);
580 	}
581 	input_sync(input);
582 }
583 
584 static int gpio_keys_open(struct input_dev *input)
585 {
586 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
587 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
588 	int error;
589 
590 	if (pdata->enable) {
591 		error = pdata->enable(input->dev.parent);
592 		if (error)
593 			return error;
594 	}
595 
596 	/* Report current state of buttons that are connected to GPIOs */
597 	gpio_keys_report_state(ddata);
598 
599 	return 0;
600 }
601 
602 static void gpio_keys_close(struct input_dev *input)
603 {
604 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
605 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
606 
607 	if (pdata->disable)
608 		pdata->disable(input->dev.parent);
609 }
610 
611 /*
612  * Handlers for alternative sources of platform_data
613  */
614 
615 #ifdef CONFIG_OF
616 /*
617  * Translate OpenFirmware node properties into platform_data
618  */
619 static struct gpio_keys_platform_data *
620 gpio_keys_get_devtree_pdata(struct device *dev)
621 {
622 	struct device_node *node, *pp;
623 	struct gpio_keys_platform_data *pdata;
624 	struct gpio_keys_button *button;
625 	int error;
626 	int nbuttons;
627 	int i;
628 
629 	node = dev->of_node;
630 	if (!node)
631 		return ERR_PTR(-ENODEV);
632 
633 	nbuttons = of_get_available_child_count(node);
634 	if (nbuttons == 0)
635 		return ERR_PTR(-ENODEV);
636 
637 	pdata = devm_kzalloc(dev,
638 			     sizeof(*pdata) + nbuttons * sizeof(*button),
639 			     GFP_KERNEL);
640 	if (!pdata)
641 		return ERR_PTR(-ENOMEM);
642 
643 	pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
644 	pdata->nbuttons = nbuttons;
645 
646 	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
647 
648 	of_property_read_string(node, "label", &pdata->name);
649 
650 	i = 0;
651 	for_each_available_child_of_node(node, pp) {
652 		enum of_gpio_flags flags;
653 
654 		button = &pdata->buttons[i++];
655 
656 		button->gpio = of_get_gpio_flags(pp, 0, &flags);
657 		if (button->gpio < 0) {
658 			error = button->gpio;
659 			if (error != -ENOENT) {
660 				if (error != -EPROBE_DEFER)
661 					dev_err(dev,
662 						"Failed to get gpio flags, error: %d\n",
663 						error);
664 				return ERR_PTR(error);
665 			}
666 		} else {
667 			button->active_low = flags & OF_GPIO_ACTIVE_LOW;
668 		}
669 
670 		button->irq = irq_of_parse_and_map(pp, 0);
671 
672 		if (!gpio_is_valid(button->gpio) && !button->irq) {
673 			dev_err(dev, "Found button without gpios or irqs\n");
674 			return ERR_PTR(-EINVAL);
675 		}
676 
677 		if (of_property_read_u32(pp, "linux,code", &button->code)) {
678 			dev_err(dev, "Button without keycode: 0x%x\n",
679 				button->gpio);
680 			return ERR_PTR(-EINVAL);
681 		}
682 
683 		button->desc = of_get_property(pp, "label", NULL);
684 
685 		if (of_property_read_u32(pp, "linux,input-type", &button->type))
686 			button->type = EV_KEY;
687 
688 		button->wakeup = of_property_read_bool(pp, "wakeup-source") ||
689 				 /* legacy name */
690 				 of_property_read_bool(pp, "gpio-key,wakeup");
691 
692 		button->can_disable = !!of_get_property(pp, "linux,can-disable", NULL);
693 
694 		if (of_property_read_u32(pp, "debounce-interval",
695 					 &button->debounce_interval))
696 			button->debounce_interval = 5;
697 	}
698 
699 	if (pdata->nbuttons == 0)
700 		return ERR_PTR(-EINVAL);
701 
702 	return pdata;
703 }
704 
705 static const struct of_device_id gpio_keys_of_match[] = {
706 	{ .compatible = "gpio-keys", },
707 	{ },
708 };
709 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
710 
711 #else
712 
713 static inline struct gpio_keys_platform_data *
714 gpio_keys_get_devtree_pdata(struct device *dev)
715 {
716 	return ERR_PTR(-ENODEV);
717 }
718 
719 #endif
720 
721 static int gpio_keys_probe(struct platform_device *pdev)
722 {
723 	struct device *dev = &pdev->dev;
724 	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
725 	struct gpio_keys_drvdata *ddata;
726 	struct input_dev *input;
727 	size_t size;
728 	int i, error;
729 	int wakeup = 0;
730 
731 	if (!pdata) {
732 		pdata = gpio_keys_get_devtree_pdata(dev);
733 		if (IS_ERR(pdata))
734 			return PTR_ERR(pdata);
735 	}
736 
737 	size = sizeof(struct gpio_keys_drvdata) +
738 			pdata->nbuttons * sizeof(struct gpio_button_data);
739 	ddata = devm_kzalloc(dev, size, GFP_KERNEL);
740 	if (!ddata) {
741 		dev_err(dev, "failed to allocate state\n");
742 		return -ENOMEM;
743 	}
744 
745 	input = devm_input_allocate_device(dev);
746 	if (!input) {
747 		dev_err(dev, "failed to allocate input device\n");
748 		return -ENOMEM;
749 	}
750 
751 	ddata->pdata = pdata;
752 	ddata->input = input;
753 	mutex_init(&ddata->disable_lock);
754 
755 	platform_set_drvdata(pdev, ddata);
756 	input_set_drvdata(input, ddata);
757 
758 	input->name = pdata->name ? : pdev->name;
759 	input->phys = "gpio-keys/input0";
760 	input->dev.parent = &pdev->dev;
761 	input->open = gpio_keys_open;
762 	input->close = gpio_keys_close;
763 
764 	input->id.bustype = BUS_HOST;
765 	input->id.vendor = 0x0001;
766 	input->id.product = 0x0001;
767 	input->id.version = 0x0100;
768 
769 	/* Enable auto repeat feature of Linux input subsystem */
770 	if (pdata->rep)
771 		__set_bit(EV_REP, input->evbit);
772 
773 	for (i = 0; i < pdata->nbuttons; i++) {
774 		const struct gpio_keys_button *button = &pdata->buttons[i];
775 		struct gpio_button_data *bdata = &ddata->data[i];
776 
777 		error = gpio_keys_setup_key(pdev, input, bdata, button);
778 		if (error)
779 			return error;
780 
781 		if (button->wakeup)
782 			wakeup = 1;
783 	}
784 
785 	error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
786 	if (error) {
787 		dev_err(dev, "Unable to export keys/switches, error: %d\n",
788 			error);
789 		return error;
790 	}
791 
792 	error = input_register_device(input);
793 	if (error) {
794 		dev_err(dev, "Unable to register input device, error: %d\n",
795 			error);
796 		goto err_remove_group;
797 	}
798 
799 	device_init_wakeup(&pdev->dev, wakeup);
800 
801 	return 0;
802 
803 err_remove_group:
804 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
805 	return error;
806 }
807 
808 static int gpio_keys_remove(struct platform_device *pdev)
809 {
810 	sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
811 
812 	device_init_wakeup(&pdev->dev, 0);
813 
814 	return 0;
815 }
816 
817 #ifdef CONFIG_PM_SLEEP
818 static int gpio_keys_suspend(struct device *dev)
819 {
820 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
821 	struct input_dev *input = ddata->input;
822 	int i;
823 
824 	if (device_may_wakeup(dev)) {
825 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
826 			struct gpio_button_data *bdata = &ddata->data[i];
827 			if (bdata->button->wakeup)
828 				enable_irq_wake(bdata->irq);
829 		}
830 	} else {
831 		mutex_lock(&input->mutex);
832 		if (input->users)
833 			gpio_keys_close(input);
834 		mutex_unlock(&input->mutex);
835 	}
836 
837 	return 0;
838 }
839 
840 static int gpio_keys_resume(struct device *dev)
841 {
842 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
843 	struct input_dev *input = ddata->input;
844 	int error = 0;
845 	int i;
846 
847 	if (device_may_wakeup(dev)) {
848 		for (i = 0; i < ddata->pdata->nbuttons; i++) {
849 			struct gpio_button_data *bdata = &ddata->data[i];
850 			if (bdata->button->wakeup)
851 				disable_irq_wake(bdata->irq);
852 		}
853 	} else {
854 		mutex_lock(&input->mutex);
855 		if (input->users)
856 			error = gpio_keys_open(input);
857 		mutex_unlock(&input->mutex);
858 	}
859 
860 	if (error)
861 		return error;
862 
863 	gpio_keys_report_state(ddata);
864 	return 0;
865 }
866 #endif
867 
868 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
869 
870 static struct platform_driver gpio_keys_device_driver = {
871 	.probe		= gpio_keys_probe,
872 	.remove		= gpio_keys_remove,
873 	.driver		= {
874 		.name	= "gpio-keys",
875 		.pm	= &gpio_keys_pm_ops,
876 		.of_match_table = of_match_ptr(gpio_keys_of_match),
877 	}
878 };
879 
880 static int __init gpio_keys_init(void)
881 {
882 	return platform_driver_register(&gpio_keys_device_driver);
883 }
884 
885 static void __exit gpio_keys_exit(void)
886 {
887 	platform_driver_unregister(&gpio_keys_device_driver);
888 }
889 
890 late_initcall(gpio_keys_init);
891 module_exit(gpio_keys_exit);
892 
893 MODULE_LICENSE("GPL");
894 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
895 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
896 MODULE_ALIAS("platform:gpio-keys");
897