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/gpio/consumer.h>
30 #include <linux/of.h>
31 #include <linux/of_irq.h>
32 #include <linux/spinlock.h>
33 #include <dt-bindings/input/gpio-keys.h>
34 
35 struct gpio_button_data {
36 	const struct gpio_keys_button *button;
37 	struct input_dev *input;
38 	struct gpio_desc *gpiod;
39 
40 	unsigned short *code;
41 
42 	struct timer_list release_timer;
43 	unsigned int release_delay;	/* in msecs, for IRQ-only buttons */
44 
45 	struct delayed_work work;
46 	unsigned int software_debounce;	/* in msecs, for GPIO-driven buttons */
47 
48 	unsigned int irq;
49 	unsigned int wakeup_trigger_type;
50 	spinlock_t lock;
51 	bool disabled;
52 	bool key_pressed;
53 	bool suspended;
54 };
55 
56 struct gpio_keys_drvdata {
57 	const struct gpio_keys_platform_data *pdata;
58 	struct input_dev *input;
59 	struct mutex disable_lock;
60 	unsigned short *keymap;
61 	struct gpio_button_data data[0];
62 };
63 
64 /*
65  * SYSFS interface for enabling/disabling keys and switches:
66  *
67  * There are 4 attributes under /sys/devices/platform/gpio-keys/
68  *	keys [ro]              - bitmap of keys (EV_KEY) which can be
69  *	                         disabled
70  *	switches [ro]          - bitmap of switches (EV_SW) which can be
71  *	                         disabled
72  *	disabled_keys [rw]     - bitmap of keys currently disabled
73  *	disabled_switches [rw] - bitmap of switches currently disabled
74  *
75  * Userland can change these values and hence disable event generation
76  * for each key (or switch). Disabling a key means its interrupt line
77  * is disabled.
78  *
79  * For example, if we have following switches set up as gpio-keys:
80  *	SW_DOCK = 5
81  *	SW_CAMERA_LENS_COVER = 9
82  *	SW_KEYPAD_SLIDE = 10
83  *	SW_FRONT_PROXIMITY = 11
84  * This is read from switches:
85  *	11-9,5
86  * Next we want to disable proximity (11) and dock (5), we write:
87  *	11,5
88  * to file disabled_switches. Now proximity and dock IRQs are disabled.
89  * This can be verified by reading the file disabled_switches:
90  *	11,5
91  * If we now want to enable proximity (11) switch we write:
92  *	5
93  * to disabled_switches.
94  *
95  * We can disable only those keys which don't allow sharing the irq.
96  */
97 
98 /**
99  * get_n_events_by_type() - returns maximum number of events per @type
100  * @type: type of button (%EV_KEY, %EV_SW)
101  *
102  * Return value of this function can be used to allocate bitmap
103  * large enough to hold all bits for given type.
104  */
105 static int get_n_events_by_type(int type)
106 {
107 	BUG_ON(type != EV_SW && type != EV_KEY);
108 
109 	return (type == EV_KEY) ? KEY_CNT : SW_CNT;
110 }
111 
112 /**
113  * get_bm_events_by_type() - returns bitmap of supported events per @type
114  * @input: input device from which bitmap is retrieved
115  * @type: type of button (%EV_KEY, %EV_SW)
116  *
117  * Return value of this function can be used to allocate bitmap
118  * large enough to hold all bits for given type.
119  */
120 static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
121 						  int type)
122 {
123 	BUG_ON(type != EV_SW && type != EV_KEY);
124 
125 	return (type == EV_KEY) ? dev->keybit : dev->swbit;
126 }
127 
128 /**
129  * gpio_keys_disable_button() - disables given GPIO button
130  * @bdata: button data for button to be disabled
131  *
132  * Disables button pointed by @bdata. This is done by masking
133  * IRQ line. After this function is called, button won't generate
134  * input events anymore. Note that one can only disable buttons
135  * that don't share IRQs.
136  *
137  * Make sure that @bdata->disable_lock is locked when entering
138  * this function to avoid races when concurrent threads are
139  * disabling buttons at the same time.
140  */
141 static void gpio_keys_disable_button(struct gpio_button_data *bdata)
142 {
143 	if (!bdata->disabled) {
144 		/*
145 		 * Disable IRQ and associated timer/work structure.
146 		 */
147 		disable_irq(bdata->irq);
148 
149 		if (bdata->gpiod)
150 			cancel_delayed_work_sync(&bdata->work);
151 		else
152 			del_timer_sync(&bdata->release_timer);
153 
154 		bdata->disabled = true;
155 	}
156 }
157 
158 /**
159  * gpio_keys_enable_button() - enables given GPIO button
160  * @bdata: button data for button to be disabled
161  *
162  * Enables given button pointed by @bdata.
163  *
164  * Make sure that @bdata->disable_lock is locked when entering
165  * this function to avoid races with concurrent threads trying
166  * to enable the same button at the same time.
167  */
168 static void gpio_keys_enable_button(struct gpio_button_data *bdata)
169 {
170 	if (bdata->disabled) {
171 		enable_irq(bdata->irq);
172 		bdata->disabled = false;
173 	}
174 }
175 
176 /**
177  * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
178  * @ddata: pointer to drvdata
179  * @buf: buffer where stringified bitmap is written
180  * @type: button type (%EV_KEY, %EV_SW)
181  * @only_disabled: does caller want only those buttons that are
182  *                 currently disabled or all buttons that can be
183  *                 disabled
184  *
185  * This function writes buttons that can be disabled to @buf. If
186  * @only_disabled is true, then @buf contains only those buttons
187  * that are currently disabled. Returns 0 on success or negative
188  * errno on failure.
189  */
190 static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
191 					  char *buf, unsigned int type,
192 					  bool only_disabled)
193 {
194 	int n_events = get_n_events_by_type(type);
195 	unsigned long *bits;
196 	ssize_t ret;
197 	int i;
198 
199 	bits = bitmap_zalloc(n_events, GFP_KERNEL);
200 	if (!bits)
201 		return -ENOMEM;
202 
203 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
204 		struct gpio_button_data *bdata = &ddata->data[i];
205 
206 		if (bdata->button->type != type)
207 			continue;
208 
209 		if (only_disabled && !bdata->disabled)
210 			continue;
211 
212 		__set_bit(*bdata->code, bits);
213 	}
214 
215 	ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
216 	buf[ret++] = '\n';
217 	buf[ret] = '\0';
218 
219 	bitmap_free(bits);
220 
221 	return ret;
222 }
223 
224 /**
225  * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
226  * @ddata: pointer to drvdata
227  * @buf: buffer from userspace that contains stringified bitmap
228  * @type: button type (%EV_KEY, %EV_SW)
229  *
230  * This function parses stringified bitmap from @buf and disables/enables
231  * GPIO buttons accordingly. Returns 0 on success and negative error
232  * on failure.
233  */
234 static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
235 					   const char *buf, unsigned int type)
236 {
237 	int n_events = get_n_events_by_type(type);
238 	const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
239 	unsigned long *bits;
240 	ssize_t error;
241 	int i;
242 
243 	bits = bitmap_zalloc(n_events, GFP_KERNEL);
244 	if (!bits)
245 		return -ENOMEM;
246 
247 	error = bitmap_parselist(buf, bits, n_events);
248 	if (error)
249 		goto out;
250 
251 	/* First validate */
252 	if (!bitmap_subset(bits, bitmap, n_events)) {
253 		error = -EINVAL;
254 		goto out;
255 	}
256 
257 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
258 		struct gpio_button_data *bdata = &ddata->data[i];
259 
260 		if (bdata->button->type != type)
261 			continue;
262 
263 		if (test_bit(*bdata->code, bits) &&
264 		    !bdata->button->can_disable) {
265 			error = -EINVAL;
266 			goto out;
267 		}
268 	}
269 
270 	mutex_lock(&ddata->disable_lock);
271 
272 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
273 		struct gpio_button_data *bdata = &ddata->data[i];
274 
275 		if (bdata->button->type != type)
276 			continue;
277 
278 		if (test_bit(*bdata->code, bits))
279 			gpio_keys_disable_button(bdata);
280 		else
281 			gpio_keys_enable_button(bdata);
282 	}
283 
284 	mutex_unlock(&ddata->disable_lock);
285 
286 out:
287 	bitmap_free(bits);
288 	return error;
289 }
290 
291 #define ATTR_SHOW_FN(name, type, only_disabled)				\
292 static ssize_t gpio_keys_show_##name(struct device *dev,		\
293 				     struct device_attribute *attr,	\
294 				     char *buf)				\
295 {									\
296 	struct platform_device *pdev = to_platform_device(dev);		\
297 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
298 									\
299 	return gpio_keys_attr_show_helper(ddata, buf,			\
300 					  type, only_disabled);		\
301 }
302 
303 ATTR_SHOW_FN(keys, EV_KEY, false);
304 ATTR_SHOW_FN(switches, EV_SW, false);
305 ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
306 ATTR_SHOW_FN(disabled_switches, EV_SW, true);
307 
308 /*
309  * ATTRIBUTES:
310  *
311  * /sys/devices/platform/gpio-keys/keys [ro]
312  * /sys/devices/platform/gpio-keys/switches [ro]
313  */
314 static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
315 static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
316 
317 #define ATTR_STORE_FN(name, type)					\
318 static ssize_t gpio_keys_store_##name(struct device *dev,		\
319 				      struct device_attribute *attr,	\
320 				      const char *buf,			\
321 				      size_t count)			\
322 {									\
323 	struct platform_device *pdev = to_platform_device(dev);		\
324 	struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);	\
325 	ssize_t error;							\
326 									\
327 	error = gpio_keys_attr_store_helper(ddata, buf, type);		\
328 	if (error)							\
329 		return error;						\
330 									\
331 	return count;							\
332 }
333 
334 ATTR_STORE_FN(disabled_keys, EV_KEY);
335 ATTR_STORE_FN(disabled_switches, EV_SW);
336 
337 /*
338  * ATTRIBUTES:
339  *
340  * /sys/devices/platform/gpio-keys/disabled_keys [rw]
341  * /sys/devices/platform/gpio-keys/disables_switches [rw]
342  */
343 static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
344 		   gpio_keys_show_disabled_keys,
345 		   gpio_keys_store_disabled_keys);
346 static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
347 		   gpio_keys_show_disabled_switches,
348 		   gpio_keys_store_disabled_switches);
349 
350 static struct attribute *gpio_keys_attrs[] = {
351 	&dev_attr_keys.attr,
352 	&dev_attr_switches.attr,
353 	&dev_attr_disabled_keys.attr,
354 	&dev_attr_disabled_switches.attr,
355 	NULL,
356 };
357 
358 static const struct attribute_group gpio_keys_attr_group = {
359 	.attrs = gpio_keys_attrs,
360 };
361 
362 static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
363 {
364 	const struct gpio_keys_button *button = bdata->button;
365 	struct input_dev *input = bdata->input;
366 	unsigned int type = button->type ?: EV_KEY;
367 	int state;
368 
369 	state = gpiod_get_value_cansleep(bdata->gpiod);
370 	if (state < 0) {
371 		dev_err(input->dev.parent,
372 			"failed to get gpio state: %d\n", state);
373 		return;
374 	}
375 
376 	if (type == EV_ABS) {
377 		if (state)
378 			input_event(input, type, button->code, button->value);
379 	} else {
380 		input_event(input, type, *bdata->code, state);
381 	}
382 	input_sync(input);
383 }
384 
385 static void gpio_keys_gpio_work_func(struct work_struct *work)
386 {
387 	struct gpio_button_data *bdata =
388 		container_of(work, struct gpio_button_data, work.work);
389 
390 	gpio_keys_gpio_report_event(bdata);
391 
392 	if (bdata->button->wakeup)
393 		pm_relax(bdata->input->dev.parent);
394 }
395 
396 static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
397 {
398 	struct gpio_button_data *bdata = dev_id;
399 
400 	BUG_ON(irq != bdata->irq);
401 
402 	if (bdata->button->wakeup) {
403 		const struct gpio_keys_button *button = bdata->button;
404 
405 		pm_stay_awake(bdata->input->dev.parent);
406 		if (bdata->suspended  &&
407 		    (button->type == 0 || button->type == EV_KEY)) {
408 			/*
409 			 * Simulate wakeup key press in case the key has
410 			 * already released by the time we got interrupt
411 			 * handler to run.
412 			 */
413 			input_report_key(bdata->input, button->code, 1);
414 		}
415 	}
416 
417 	mod_delayed_work(system_wq,
418 			 &bdata->work,
419 			 msecs_to_jiffies(bdata->software_debounce));
420 
421 	return IRQ_HANDLED;
422 }
423 
424 static void gpio_keys_irq_timer(struct timer_list *t)
425 {
426 	struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
427 	struct input_dev *input = bdata->input;
428 	unsigned long flags;
429 
430 	spin_lock_irqsave(&bdata->lock, flags);
431 	if (bdata->key_pressed) {
432 		input_event(input, EV_KEY, *bdata->code, 0);
433 		input_sync(input);
434 		bdata->key_pressed = false;
435 	}
436 	spin_unlock_irqrestore(&bdata->lock, flags);
437 }
438 
439 static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
440 {
441 	struct gpio_button_data *bdata = dev_id;
442 	struct input_dev *input = bdata->input;
443 	unsigned long flags;
444 
445 	BUG_ON(irq != bdata->irq);
446 
447 	spin_lock_irqsave(&bdata->lock, flags);
448 
449 	if (!bdata->key_pressed) {
450 		if (bdata->button->wakeup)
451 			pm_wakeup_event(bdata->input->dev.parent, 0);
452 
453 		input_event(input, EV_KEY, *bdata->code, 1);
454 		input_sync(input);
455 
456 		if (!bdata->release_delay) {
457 			input_event(input, EV_KEY, *bdata->code, 0);
458 			input_sync(input);
459 			goto out;
460 		}
461 
462 		bdata->key_pressed = true;
463 	}
464 
465 	if (bdata->release_delay)
466 		mod_timer(&bdata->release_timer,
467 			jiffies + msecs_to_jiffies(bdata->release_delay));
468 out:
469 	spin_unlock_irqrestore(&bdata->lock, flags);
470 	return IRQ_HANDLED;
471 }
472 
473 static void gpio_keys_quiesce_key(void *data)
474 {
475 	struct gpio_button_data *bdata = data;
476 
477 	if (bdata->gpiod)
478 		cancel_delayed_work_sync(&bdata->work);
479 	else
480 		del_timer_sync(&bdata->release_timer);
481 }
482 
483 static int gpio_keys_setup_key(struct platform_device *pdev,
484 				struct input_dev *input,
485 				struct gpio_keys_drvdata *ddata,
486 				const struct gpio_keys_button *button,
487 				int idx,
488 				struct fwnode_handle *child)
489 {
490 	const char *desc = button->desc ? button->desc : "gpio_keys";
491 	struct device *dev = &pdev->dev;
492 	struct gpio_button_data *bdata = &ddata->data[idx];
493 	irq_handler_t isr;
494 	unsigned long irqflags;
495 	int irq;
496 	int error;
497 
498 	bdata->input = input;
499 	bdata->button = button;
500 	spin_lock_init(&bdata->lock);
501 
502 	if (child) {
503 		bdata->gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL,
504 								child,
505 								GPIOD_IN,
506 								desc);
507 		if (IS_ERR(bdata->gpiod)) {
508 			error = PTR_ERR(bdata->gpiod);
509 			if (error == -ENOENT) {
510 				/*
511 				 * GPIO is optional, we may be dealing with
512 				 * purely interrupt-driven setup.
513 				 */
514 				bdata->gpiod = NULL;
515 			} else {
516 				if (error != -EPROBE_DEFER)
517 					dev_err(dev, "failed to get gpio: %d\n",
518 						error);
519 				return error;
520 			}
521 		}
522 	} else if (gpio_is_valid(button->gpio)) {
523 		/*
524 		 * Legacy GPIO number, so request the GPIO here and
525 		 * convert it to descriptor.
526 		 */
527 		unsigned flags = GPIOF_IN;
528 
529 		if (button->active_low)
530 			flags |= GPIOF_ACTIVE_LOW;
531 
532 		error = devm_gpio_request_one(dev, button->gpio, flags, desc);
533 		if (error < 0) {
534 			dev_err(dev, "Failed to request GPIO %d, error %d\n",
535 				button->gpio, error);
536 			return error;
537 		}
538 
539 		bdata->gpiod = gpio_to_desc(button->gpio);
540 		if (!bdata->gpiod)
541 			return -EINVAL;
542 	}
543 
544 	if (bdata->gpiod) {
545 		bool active_low = gpiod_is_active_low(bdata->gpiod);
546 
547 		if (button->debounce_interval) {
548 			error = gpiod_set_debounce(bdata->gpiod,
549 					button->debounce_interval * 1000);
550 			/* use timer if gpiolib doesn't provide debounce */
551 			if (error < 0)
552 				bdata->software_debounce =
553 						button->debounce_interval;
554 		}
555 
556 		if (button->irq) {
557 			bdata->irq = button->irq;
558 		} else {
559 			irq = gpiod_to_irq(bdata->gpiod);
560 			if (irq < 0) {
561 				error = irq;
562 				dev_err(dev,
563 					"Unable to get irq number for GPIO %d, error %d\n",
564 					button->gpio, error);
565 				return error;
566 			}
567 			bdata->irq = irq;
568 		}
569 
570 		INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
571 
572 		isr = gpio_keys_gpio_isr;
573 		irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
574 
575 		switch (button->wakeup_event_action) {
576 		case EV_ACT_ASSERTED:
577 			bdata->wakeup_trigger_type = active_low ?
578 				IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
579 			break;
580 		case EV_ACT_DEASSERTED:
581 			bdata->wakeup_trigger_type = active_low ?
582 				IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
583 			break;
584 		case EV_ACT_ANY:
585 			/* fall through */
586 		default:
587 			/*
588 			 * For other cases, we are OK letting suspend/resume
589 			 * not reconfigure the trigger type.
590 			 */
591 			break;
592 		}
593 	} else {
594 		if (!button->irq) {
595 			dev_err(dev, "Found button without gpio or irq\n");
596 			return -EINVAL;
597 		}
598 
599 		bdata->irq = button->irq;
600 
601 		if (button->type && button->type != EV_KEY) {
602 			dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
603 			return -EINVAL;
604 		}
605 
606 		bdata->release_delay = button->debounce_interval;
607 		timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
608 
609 		isr = gpio_keys_irq_isr;
610 		irqflags = 0;
611 
612 		/*
613 		 * For IRQ buttons, there is no interrupt for release.
614 		 * So we don't need to reconfigure the trigger type for wakeup.
615 		 */
616 	}
617 
618 	bdata->code = &ddata->keymap[idx];
619 	*bdata->code = button->code;
620 	input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
621 
622 	/*
623 	 * Install custom action to cancel release timer and
624 	 * workqueue item.
625 	 */
626 	error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
627 	if (error) {
628 		dev_err(dev, "failed to register quiesce action, error: %d\n",
629 			error);
630 		return error;
631 	}
632 
633 	/*
634 	 * If platform has specified that the button can be disabled,
635 	 * we don't want it to share the interrupt line.
636 	 */
637 	if (!button->can_disable)
638 		irqflags |= IRQF_SHARED;
639 
640 	error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
641 					     desc, bdata);
642 	if (error < 0) {
643 		dev_err(dev, "Unable to claim irq %d; error %d\n",
644 			bdata->irq, error);
645 		return error;
646 	}
647 
648 	return 0;
649 }
650 
651 static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
652 {
653 	struct input_dev *input = ddata->input;
654 	int i;
655 
656 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
657 		struct gpio_button_data *bdata = &ddata->data[i];
658 		if (bdata->gpiod)
659 			gpio_keys_gpio_report_event(bdata);
660 	}
661 	input_sync(input);
662 }
663 
664 static int gpio_keys_open(struct input_dev *input)
665 {
666 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
667 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
668 	int error;
669 
670 	if (pdata->enable) {
671 		error = pdata->enable(input->dev.parent);
672 		if (error)
673 			return error;
674 	}
675 
676 	/* Report current state of buttons that are connected to GPIOs */
677 	gpio_keys_report_state(ddata);
678 
679 	return 0;
680 }
681 
682 static void gpio_keys_close(struct input_dev *input)
683 {
684 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
685 	const struct gpio_keys_platform_data *pdata = ddata->pdata;
686 
687 	if (pdata->disable)
688 		pdata->disable(input->dev.parent);
689 }
690 
691 /*
692  * Handlers for alternative sources of platform_data
693  */
694 
695 /*
696  * Translate properties into platform_data
697  */
698 static struct gpio_keys_platform_data *
699 gpio_keys_get_devtree_pdata(struct device *dev)
700 {
701 	struct gpio_keys_platform_data *pdata;
702 	struct gpio_keys_button *button;
703 	struct fwnode_handle *child;
704 	int nbuttons;
705 
706 	nbuttons = device_get_child_node_count(dev);
707 	if (nbuttons == 0)
708 		return ERR_PTR(-ENODEV);
709 
710 	pdata = devm_kzalloc(dev,
711 			     sizeof(*pdata) + nbuttons * sizeof(*button),
712 			     GFP_KERNEL);
713 	if (!pdata)
714 		return ERR_PTR(-ENOMEM);
715 
716 	button = (struct gpio_keys_button *)(pdata + 1);
717 
718 	pdata->buttons = button;
719 	pdata->nbuttons = nbuttons;
720 
721 	pdata->rep = device_property_read_bool(dev, "autorepeat");
722 
723 	device_property_read_string(dev, "label", &pdata->name);
724 
725 	device_for_each_child_node(dev, child) {
726 		if (is_of_node(child))
727 			button->irq =
728 				irq_of_parse_and_map(to_of_node(child), 0);
729 
730 		if (fwnode_property_read_u32(child, "linux,code",
731 					     &button->code)) {
732 			dev_err(dev, "Button without keycode\n");
733 			fwnode_handle_put(child);
734 			return ERR_PTR(-EINVAL);
735 		}
736 
737 		fwnode_property_read_string(child, "label", &button->desc);
738 
739 		if (fwnode_property_read_u32(child, "linux,input-type",
740 					     &button->type))
741 			button->type = EV_KEY;
742 
743 		button->wakeup =
744 			fwnode_property_read_bool(child, "wakeup-source") ||
745 			/* legacy name */
746 			fwnode_property_read_bool(child, "gpio-key,wakeup");
747 
748 		fwnode_property_read_u32(child, "wakeup-event-action",
749 					 &button->wakeup_event_action);
750 
751 		button->can_disable =
752 			fwnode_property_read_bool(child, "linux,can-disable");
753 
754 		if (fwnode_property_read_u32(child, "debounce-interval",
755 					 &button->debounce_interval))
756 			button->debounce_interval = 5;
757 
758 		button++;
759 	}
760 
761 	return pdata;
762 }
763 
764 static const struct of_device_id gpio_keys_of_match[] = {
765 	{ .compatible = "gpio-keys", },
766 	{ },
767 };
768 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
769 
770 static int gpio_keys_probe(struct platform_device *pdev)
771 {
772 	struct device *dev = &pdev->dev;
773 	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
774 	struct fwnode_handle *child = NULL;
775 	struct gpio_keys_drvdata *ddata;
776 	struct input_dev *input;
777 	size_t size;
778 	int i, error;
779 	int wakeup = 0;
780 
781 	if (!pdata) {
782 		pdata = gpio_keys_get_devtree_pdata(dev);
783 		if (IS_ERR(pdata))
784 			return PTR_ERR(pdata);
785 	}
786 
787 	size = sizeof(struct gpio_keys_drvdata) +
788 			pdata->nbuttons * sizeof(struct gpio_button_data);
789 	ddata = devm_kzalloc(dev, size, GFP_KERNEL);
790 	if (!ddata) {
791 		dev_err(dev, "failed to allocate state\n");
792 		return -ENOMEM;
793 	}
794 
795 	ddata->keymap = devm_kcalloc(dev,
796 				     pdata->nbuttons, sizeof(ddata->keymap[0]),
797 				     GFP_KERNEL);
798 	if (!ddata->keymap)
799 		return -ENOMEM;
800 
801 	input = devm_input_allocate_device(dev);
802 	if (!input) {
803 		dev_err(dev, "failed to allocate input device\n");
804 		return -ENOMEM;
805 	}
806 
807 	ddata->pdata = pdata;
808 	ddata->input = input;
809 	mutex_init(&ddata->disable_lock);
810 
811 	platform_set_drvdata(pdev, ddata);
812 	input_set_drvdata(input, ddata);
813 
814 	input->name = pdata->name ? : pdev->name;
815 	input->phys = "gpio-keys/input0";
816 	input->dev.parent = dev;
817 	input->open = gpio_keys_open;
818 	input->close = gpio_keys_close;
819 
820 	input->id.bustype = BUS_HOST;
821 	input->id.vendor = 0x0001;
822 	input->id.product = 0x0001;
823 	input->id.version = 0x0100;
824 
825 	input->keycode = ddata->keymap;
826 	input->keycodesize = sizeof(ddata->keymap[0]);
827 	input->keycodemax = pdata->nbuttons;
828 
829 	/* Enable auto repeat feature of Linux input subsystem */
830 	if (pdata->rep)
831 		__set_bit(EV_REP, input->evbit);
832 
833 	for (i = 0; i < pdata->nbuttons; i++) {
834 		const struct gpio_keys_button *button = &pdata->buttons[i];
835 
836 		if (!dev_get_platdata(dev)) {
837 			child = device_get_next_child_node(dev, child);
838 			if (!child) {
839 				dev_err(dev,
840 					"missing child device node for entry %d\n",
841 					i);
842 				return -EINVAL;
843 			}
844 		}
845 
846 		error = gpio_keys_setup_key(pdev, input, ddata,
847 					    button, i, child);
848 		if (error) {
849 			fwnode_handle_put(child);
850 			return error;
851 		}
852 
853 		if (button->wakeup)
854 			wakeup = 1;
855 	}
856 
857 	fwnode_handle_put(child);
858 
859 	error = devm_device_add_group(dev, &gpio_keys_attr_group);
860 	if (error) {
861 		dev_err(dev, "Unable to export keys/switches, error: %d\n",
862 			error);
863 		return error;
864 	}
865 
866 	error = input_register_device(input);
867 	if (error) {
868 		dev_err(dev, "Unable to register input device, error: %d\n",
869 			error);
870 		return error;
871 	}
872 
873 	device_init_wakeup(dev, wakeup);
874 
875 	return 0;
876 }
877 
878 static int __maybe_unused
879 gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
880 {
881 	int error;
882 
883 	error = enable_irq_wake(bdata->irq);
884 	if (error) {
885 		dev_err(bdata->input->dev.parent,
886 			"failed to configure IRQ %d as wakeup source: %d\n",
887 			bdata->irq, error);
888 		return error;
889 	}
890 
891 	if (bdata->wakeup_trigger_type) {
892 		error = irq_set_irq_type(bdata->irq,
893 					 bdata->wakeup_trigger_type);
894 		if (error) {
895 			dev_err(bdata->input->dev.parent,
896 				"failed to set wakeup trigger %08x for IRQ %d: %d\n",
897 				bdata->wakeup_trigger_type, bdata->irq, error);
898 			disable_irq_wake(bdata->irq);
899 			return error;
900 		}
901 	}
902 
903 	return 0;
904 }
905 
906 static void __maybe_unused
907 gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
908 {
909 	int error;
910 
911 	/*
912 	 * The trigger type is always both edges for gpio-based keys and we do
913 	 * not support changing wakeup trigger for interrupt-based keys.
914 	 */
915 	if (bdata->wakeup_trigger_type) {
916 		error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
917 		if (error)
918 			dev_warn(bdata->input->dev.parent,
919 				 "failed to restore interrupt trigger for IRQ %d: %d\n",
920 				 bdata->irq, error);
921 	}
922 
923 	error = disable_irq_wake(bdata->irq);
924 	if (error)
925 		dev_warn(bdata->input->dev.parent,
926 			 "failed to disable IRQ %d as wake source: %d\n",
927 			 bdata->irq, error);
928 }
929 
930 static int __maybe_unused
931 gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
932 {
933 	struct gpio_button_data *bdata;
934 	int error;
935 	int i;
936 
937 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
938 		bdata = &ddata->data[i];
939 		if (bdata->button->wakeup) {
940 			error = gpio_keys_button_enable_wakeup(bdata);
941 			if (error)
942 				goto err_out;
943 		}
944 		bdata->suspended = true;
945 	}
946 
947 	return 0;
948 
949 err_out:
950 	while (i--) {
951 		bdata = &ddata->data[i];
952 		if (bdata->button->wakeup)
953 			gpio_keys_button_disable_wakeup(bdata);
954 		bdata->suspended = false;
955 	}
956 
957 	return error;
958 }
959 
960 static void __maybe_unused
961 gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
962 {
963 	struct gpio_button_data *bdata;
964 	int i;
965 
966 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
967 		bdata = &ddata->data[i];
968 		bdata->suspended = false;
969 		if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
970 			gpio_keys_button_disable_wakeup(bdata);
971 	}
972 }
973 
974 static int __maybe_unused gpio_keys_suspend(struct device *dev)
975 {
976 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
977 	struct input_dev *input = ddata->input;
978 	int error;
979 
980 	if (device_may_wakeup(dev)) {
981 		error = gpio_keys_enable_wakeup(ddata);
982 		if (error)
983 			return error;
984 	} else {
985 		mutex_lock(&input->mutex);
986 		if (input->users)
987 			gpio_keys_close(input);
988 		mutex_unlock(&input->mutex);
989 	}
990 
991 	return 0;
992 }
993 
994 static int __maybe_unused gpio_keys_resume(struct device *dev)
995 {
996 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
997 	struct input_dev *input = ddata->input;
998 	int error = 0;
999 
1000 	if (device_may_wakeup(dev)) {
1001 		gpio_keys_disable_wakeup(ddata);
1002 	} else {
1003 		mutex_lock(&input->mutex);
1004 		if (input->users)
1005 			error = gpio_keys_open(input);
1006 		mutex_unlock(&input->mutex);
1007 	}
1008 
1009 	if (error)
1010 		return error;
1011 
1012 	gpio_keys_report_state(ddata);
1013 	return 0;
1014 }
1015 
1016 static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1017 
1018 static struct platform_driver gpio_keys_device_driver = {
1019 	.probe		= gpio_keys_probe,
1020 	.driver		= {
1021 		.name	= "gpio-keys",
1022 		.pm	= &gpio_keys_pm_ops,
1023 		.of_match_table = gpio_keys_of_match,
1024 	}
1025 };
1026 
1027 static int __init gpio_keys_init(void)
1028 {
1029 	return platform_driver_register(&gpio_keys_device_driver);
1030 }
1031 
1032 static void __exit gpio_keys_exit(void)
1033 {
1034 	platform_driver_unregister(&gpio_keys_device_driver);
1035 }
1036 
1037 late_initcall(gpio_keys_init);
1038 module_exit(gpio_keys_exit);
1039 
1040 MODULE_LICENSE("GPL");
1041 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1042 MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1043 MODULE_ALIAS("platform:gpio-keys");
1044