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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for keys on GPIO lines capable of generating interrupts.
4 *
5 * Copyright 2005 Phil Blundell
6 * Copyright 2010, 2011 David Jander <david@protonic.nl>
7 */
8
9#include <linux/module.h>
10
11#include <linux/hrtimer.h>
12#include <linux/init.h>
13#include <linux/fs.h>
14#include <linux/interrupt.h>
15#include <linux/irq.h>
16#include <linux/sched.h>
17#include <linux/pm.h>
18#include <linux/slab.h>
19#include <linux/sysctl.h>
20#include <linux/proc_fs.h>
21#include <linux/delay.h>
22#include <linux/platform_device.h>
23#include <linux/input.h>
24#include <linux/gpio_keys.h>
25#include <linux/workqueue.h>
26#include <linux/gpio.h>
27#include <linux/gpio/consumer.h>
28#include <linux/of.h>
29#include <linux/of_irq.h>
30#include <linux/spinlock.h>
31#include <dt-bindings/input/gpio-keys.h>
32
33struct gpio_button_data {
34 const struct gpio_keys_button *button;
35 struct input_dev *input;
36 struct gpio_desc *gpiod;
37
38 unsigned short *code;
39
40 struct hrtimer release_timer;
41 unsigned int release_delay; /* in msecs, for IRQ-only buttons */
42
43 struct delayed_work work;
44 struct hrtimer debounce_timer;
45 unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
46
47 unsigned int irq;
48 unsigned int wakeirq;
49 unsigned int wakeup_trigger_type;
50
51 spinlock_t lock;
52 bool disabled;
53 bool key_pressed;
54 bool suspended;
55 bool debounce_use_hrtimer;
56};
57
58struct gpio_keys_drvdata {
59 const struct gpio_keys_platform_data *pdata;
60 struct input_dev *input;
61 struct mutex disable_lock;
62 unsigned short *keymap;
63 struct gpio_button_data data[];
64};
65
66/*
67 * SYSFS interface for enabling/disabling keys and switches:
68 *
69 * There are 4 attributes under /sys/devices/platform/gpio-keys/
70 * keys [ro] - bitmap of keys (EV_KEY) which can be
71 * disabled
72 * switches [ro] - bitmap of switches (EV_SW) which can be
73 * disabled
74 * disabled_keys [rw] - bitmap of keys currently disabled
75 * disabled_switches [rw] - bitmap of switches currently disabled
76 *
77 * Userland can change these values and hence disable event generation
78 * for each key (or switch). Disabling a key means its interrupt line
79 * is disabled.
80 *
81 * For example, if we have following switches set up as gpio-keys:
82 * SW_DOCK = 5
83 * SW_CAMERA_LENS_COVER = 9
84 * SW_KEYPAD_SLIDE = 10
85 * SW_FRONT_PROXIMITY = 11
86 * This is read from switches:
87 * 11-9,5
88 * Next we want to disable proximity (11) and dock (5), we write:
89 * 11,5
90 * to file disabled_switches. Now proximity and dock IRQs are disabled.
91 * This can be verified by reading the file disabled_switches:
92 * 11,5
93 * If we now want to enable proximity (11) switch we write:
94 * 5
95 * to disabled_switches.
96 *
97 * We can disable only those keys which don't allow sharing the irq.
98 */
99
100/**
101 * get_n_events_by_type() - returns maximum number of events per @type
102 * @type: type of button (%EV_KEY, %EV_SW)
103 *
104 * Return value of this function can be used to allocate bitmap
105 * large enough to hold all bits for given type.
106 */
107static int get_n_events_by_type(int type)
108{
109 BUG_ON(type != EV_SW && type != EV_KEY);
110
111 return (type == EV_KEY) ? KEY_CNT : SW_CNT;
112}
113
114/**
115 * get_bm_events_by_type() - returns bitmap of supported events per @type
116 * @dev: input device from which bitmap is retrieved
117 * @type: type of button (%EV_KEY, %EV_SW)
118 *
119 * Return value of this function can be used to allocate bitmap
120 * large enough to hold all bits for given type.
121 */
122static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
123 int type)
124{
125 BUG_ON(type != EV_SW && type != EV_KEY);
126
127 return (type == EV_KEY) ? dev->keybit : dev->swbit;
128}
129
130static void gpio_keys_quiesce_key(void *data)
131{
132 struct gpio_button_data *bdata = data;
133
134 if (!bdata->gpiod)
135 hrtimer_cancel(&bdata->release_timer);
136 else if (bdata->debounce_use_hrtimer)
137 hrtimer_cancel(&bdata->debounce_timer);
138 else
139 cancel_delayed_work_sync(&bdata->work);
140}
141
142/**
143 * gpio_keys_disable_button() - disables given GPIO button
144 * @bdata: button data for button to be disabled
145 *
146 * Disables button pointed by @bdata. This is done by masking
147 * IRQ line. After this function is called, button won't generate
148 * input events anymore. Note that one can only disable buttons
149 * that don't share IRQs.
150 *
151 * Make sure that @bdata->disable_lock is locked when entering
152 * this function to avoid races when concurrent threads are
153 * disabling buttons at the same time.
154 */
155static void gpio_keys_disable_button(struct gpio_button_data *bdata)
156{
157 if (!bdata->disabled) {
158 /*
159 * Disable IRQ and associated timer/work structure.
160 */
161 disable_irq(bdata->irq);
162 gpio_keys_quiesce_key(bdata);
163 bdata->disabled = true;
164 }
165}
166
167/**
168 * gpio_keys_enable_button() - enables given GPIO button
169 * @bdata: button data for button to be disabled
170 *
171 * Enables given button pointed by @bdata.
172 *
173 * Make sure that @bdata->disable_lock is locked when entering
174 * this function to avoid races with concurrent threads trying
175 * to enable the same button at the same time.
176 */
177static void gpio_keys_enable_button(struct gpio_button_data *bdata)
178{
179 if (bdata->disabled) {
180 enable_irq(bdata->irq);
181 bdata->disabled = false;
182 }
183}
184
185/**
186 * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
187 * @ddata: pointer to drvdata
188 * @buf: buffer where stringified bitmap is written
189 * @type: button type (%EV_KEY, %EV_SW)
190 * @only_disabled: does caller want only those buttons that are
191 * currently disabled or all buttons that can be
192 * disabled
193 *
194 * This function writes buttons that can be disabled to @buf. If
195 * @only_disabled is true, then @buf contains only those buttons
196 * that are currently disabled. Returns 0 on success or negative
197 * errno on failure.
198 */
199static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
200 char *buf, unsigned int type,
201 bool only_disabled)
202{
203 int n_events = get_n_events_by_type(type);
204 unsigned long *bits;
205 ssize_t ret;
206 int i;
207
208 bits = bitmap_zalloc(n_events, GFP_KERNEL);
209 if (!bits)
210 return -ENOMEM;
211
212 for (i = 0; i < ddata->pdata->nbuttons; i++) {
213 struct gpio_button_data *bdata = &ddata->data[i];
214
215 if (bdata->button->type != type)
216 continue;
217
218 if (only_disabled && !bdata->disabled)
219 continue;
220
221 __set_bit(*bdata->code, bits);
222 }
223
224 ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
225 buf[ret++] = '\n';
226 buf[ret] = '\0';
227
228 bitmap_free(bits);
229
230 return ret;
231}
232
233/**
234 * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
235 * @ddata: pointer to drvdata
236 * @buf: buffer from userspace that contains stringified bitmap
237 * @type: button type (%EV_KEY, %EV_SW)
238 *
239 * This function parses stringified bitmap from @buf and disables/enables
240 * GPIO buttons accordingly. Returns 0 on success and negative error
241 * on failure.
242 */
243static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
244 const char *buf, unsigned int type)
245{
246 int n_events = get_n_events_by_type(type);
247 const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
248 ssize_t error;
249 int i;
250
251 unsigned long *bits __free(bitmap) = bitmap_alloc(n_events, GFP_KERNEL);
252 if (!bits)
253 return -ENOMEM;
254
255 error = bitmap_parselist(buf, bits, n_events);
256 if (error)
257 return error;
258
259 /* First validate */
260 if (!bitmap_subset(bits, bitmap, n_events))
261 return -EINVAL;
262
263 for (i = 0; i < ddata->pdata->nbuttons; i++) {
264 struct gpio_button_data *bdata = &ddata->data[i];
265
266 if (bdata->button->type != type)
267 continue;
268
269 if (test_bit(*bdata->code, bits) &&
270 !bdata->button->can_disable) {
271 return -EINVAL;
272 }
273 }
274
275 guard(mutex)(&ddata->disable_lock);
276
277 for (i = 0; i < ddata->pdata->nbuttons; i++) {
278 struct gpio_button_data *bdata = &ddata->data[i];
279
280 if (bdata->button->type != type)
281 continue;
282
283 if (test_bit(*bdata->code, bits))
284 gpio_keys_disable_button(bdata);
285 else
286 gpio_keys_enable_button(bdata);
287 }
288
289 return 0;
290}
291
292#define ATTR_SHOW_FN(name, type, only_disabled) \
293static ssize_t gpio_keys_show_##name(struct device *dev, \
294 struct device_attribute *attr, \
295 char *buf) \
296{ \
297 struct platform_device *pdev = to_platform_device(dev); \
298 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
299 \
300 return gpio_keys_attr_show_helper(ddata, buf, \
301 type, only_disabled); \
302}
303
304ATTR_SHOW_FN(keys, EV_KEY, false);
305ATTR_SHOW_FN(switches, EV_SW, false);
306ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
307ATTR_SHOW_FN(disabled_switches, EV_SW, true);
308
309/*
310 * ATTRIBUTES:
311 *
312 * /sys/devices/platform/gpio-keys/keys [ro]
313 * /sys/devices/platform/gpio-keys/switches [ro]
314 */
315static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
316static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
317
318#define ATTR_STORE_FN(name, type) \
319static ssize_t gpio_keys_store_##name(struct device *dev, \
320 struct device_attribute *attr, \
321 const char *buf, \
322 size_t count) \
323{ \
324 struct platform_device *pdev = to_platform_device(dev); \
325 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
326 ssize_t error; \
327 \
328 error = gpio_keys_attr_store_helper(ddata, buf, type); \
329 if (error) \
330 return error; \
331 \
332 return count; \
333}
334
335ATTR_STORE_FN(disabled_keys, EV_KEY);
336ATTR_STORE_FN(disabled_switches, EV_SW);
337
338/*
339 * ATTRIBUTES:
340 *
341 * /sys/devices/platform/gpio-keys/disabled_keys [rw]
342 * /sys/devices/platform/gpio-keys/disables_switches [rw]
343 */
344static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
345 gpio_keys_show_disabled_keys,
346 gpio_keys_store_disabled_keys);
347static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
348 gpio_keys_show_disabled_switches,
349 gpio_keys_store_disabled_switches);
350
351static struct attribute *gpio_keys_attrs[] = {
352 &dev_attr_keys.attr,
353 &dev_attr_switches.attr,
354 &dev_attr_disabled_keys.attr,
355 &dev_attr_disabled_switches.attr,
356 NULL,
357};
358ATTRIBUTE_GROUPS(gpio_keys);
359
360static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
361{
362 const struct gpio_keys_button *button = bdata->button;
363 struct input_dev *input = bdata->input;
364 unsigned int type = button->type ?: EV_KEY;
365 int state;
366
367 state = bdata->debounce_use_hrtimer ?
368 gpiod_get_value(bdata->gpiod) :
369 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}
383
384static void gpio_keys_debounce_event(struct gpio_button_data *bdata)
385{
386 gpio_keys_gpio_report_event(bdata);
387 input_sync(bdata->input);
388
389 if (bdata->button->wakeup)
390 pm_relax(bdata->input->dev.parent);
391}
392
393static void gpio_keys_gpio_work_func(struct work_struct *work)
394{
395 struct gpio_button_data *bdata =
396 container_of(work, struct gpio_button_data, work.work);
397
398 gpio_keys_debounce_event(bdata);
399}
400
401static enum hrtimer_restart gpio_keys_debounce_timer(struct hrtimer *t)
402{
403 struct gpio_button_data *bdata =
404 container_of(t, struct gpio_button_data, debounce_timer);
405
406 gpio_keys_debounce_event(bdata);
407
408 return HRTIMER_NORESTART;
409}
410
411static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
412{
413 struct gpio_button_data *bdata = dev_id;
414
415 BUG_ON(irq != bdata->irq);
416
417 if (bdata->button->wakeup) {
418 const struct gpio_keys_button *button = bdata->button;
419
420 pm_stay_awake(bdata->input->dev.parent);
421 if (bdata->suspended &&
422 (button->type == 0 || button->type == EV_KEY)) {
423 /*
424 * Simulate wakeup key press in case the key has
425 * already released by the time we got interrupt
426 * handler to run.
427 */
428 input_report_key(bdata->input, button->code, 1);
429 }
430 }
431
432 if (bdata->debounce_use_hrtimer) {
433 hrtimer_start(&bdata->debounce_timer,
434 ms_to_ktime(bdata->software_debounce),
435 HRTIMER_MODE_REL);
436 } else {
437 mod_delayed_work(system_wq,
438 &bdata->work,
439 msecs_to_jiffies(bdata->software_debounce));
440 }
441
442 return IRQ_HANDLED;
443}
444
445static enum hrtimer_restart gpio_keys_irq_timer(struct hrtimer *t)
446{
447 struct gpio_button_data *bdata = container_of(t,
448 struct gpio_button_data,
449 release_timer);
450 struct input_dev *input = bdata->input;
451
452 if (bdata->key_pressed) {
453 input_report_key(input, *bdata->code, 0);
454 input_sync(input);
455 bdata->key_pressed = false;
456 }
457
458 return HRTIMER_NORESTART;
459}
460
461static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
462{
463 struct gpio_button_data *bdata = dev_id;
464 struct input_dev *input = bdata->input;
465
466 BUG_ON(irq != bdata->irq);
467
468 guard(spinlock_irqsave)(&bdata->lock);
469
470 if (!bdata->key_pressed) {
471 if (bdata->button->wakeup)
472 pm_wakeup_event(bdata->input->dev.parent, 0);
473
474 input_report_key(input, *bdata->code, 1);
475 input_sync(input);
476
477 if (!bdata->release_delay) {
478 input_report_key(input, *bdata->code, 0);
479 input_sync(input);
480 goto out;
481 }
482
483 bdata->key_pressed = true;
484 }
485
486 if (bdata->release_delay)
487 hrtimer_start(&bdata->release_timer,
488 ms_to_ktime(bdata->release_delay),
489 HRTIMER_MODE_REL_HARD);
490out:
491 return IRQ_HANDLED;
492}
493
494static int gpio_keys_setup_key(struct platform_device *pdev,
495 struct input_dev *input,
496 struct gpio_keys_drvdata *ddata,
497 const struct gpio_keys_button *button,
498 int idx,
499 struct fwnode_handle *child)
500{
501 const char *desc = button->desc ? button->desc : "gpio_keys";
502 struct device *dev = &pdev->dev;
503 struct gpio_button_data *bdata = &ddata->data[idx];
504 irq_handler_t isr;
505 unsigned long irqflags;
506 const char *wakedesc;
507 int irq;
508 int error;
509
510 bdata->input = input;
511 bdata->button = button;
512 spin_lock_init(&bdata->lock);
513
514 if (child) {
515 bdata->gpiod = devm_fwnode_gpiod_get(dev, child,
516 NULL, GPIOD_IN, desc);
517 if (IS_ERR(bdata->gpiod)) {
518 error = PTR_ERR(bdata->gpiod);
519 if (error != -ENOENT)
520 return dev_err_probe(dev, error,
521 "failed to get gpio\n");
522
523 /*
524 * GPIO is optional, we may be dealing with
525 * purely interrupt-driven setup.
526 */
527 bdata->gpiod = NULL;
528 }
529 } else if (gpio_is_valid(button->gpio)) {
530 /*
531 * Legacy GPIO number, so request the GPIO here and
532 * convert it to descriptor.
533 */
534 error = devm_gpio_request_one(dev, button->gpio, GPIOF_IN, desc);
535 if (error < 0) {
536 dev_err(dev, "Failed to request GPIO %d, error %d\n",
537 button->gpio, error);
538 return error;
539 }
540
541 bdata->gpiod = gpio_to_desc(button->gpio);
542 if (!bdata->gpiod)
543 return -EINVAL;
544
545 if (button->active_low ^ gpiod_is_active_low(bdata->gpiod))
546 gpiod_toggle_active_low(bdata->gpiod);
547 }
548
549 if (bdata->gpiod) {
550 bool active_low = gpiod_is_active_low(bdata->gpiod);
551
552 if (button->debounce_interval) {
553 error = gpiod_set_debounce(bdata->gpiod,
554 button->debounce_interval * 1000);
555 /* use timer if gpiolib doesn't provide debounce */
556 if (error < 0)
557 bdata->software_debounce =
558 button->debounce_interval;
559
560 /*
561 * If reading the GPIO won't sleep, we can use a
562 * hrtimer instead of a standard timer for the software
563 * debounce, to reduce the latency as much as possible.
564 */
565 bdata->debounce_use_hrtimer =
566 !gpiod_cansleep(bdata->gpiod);
567 }
568
569 /*
570 * If an interrupt was specified, use it instead of the gpio
571 * interrupt and use the gpio for reading the state. A separate
572 * interrupt may be used as the main button interrupt for
573 * runtime PM to detect events also in deeper idle states. If a
574 * dedicated wakeirq is used for system suspend only, see below
575 * for bdata->wakeirq setup.
576 */
577 if (button->irq) {
578 bdata->irq = button->irq;
579 } else {
580 irq = gpiod_to_irq(bdata->gpiod);
581 if (irq < 0) {
582 error = irq;
583 dev_err_probe(dev, error,
584 "Unable to get irq number for GPIO %d\n",
585 button->gpio);
586 return error;
587 }
588 bdata->irq = irq;
589 }
590
591 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
592
593 hrtimer_init(&bdata->debounce_timer,
594 CLOCK_REALTIME, HRTIMER_MODE_REL);
595 bdata->debounce_timer.function = gpio_keys_debounce_timer;
596
597 isr = gpio_keys_gpio_isr;
598 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
599
600 switch (button->wakeup_event_action) {
601 case EV_ACT_ASSERTED:
602 bdata->wakeup_trigger_type = active_low ?
603 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
604 break;
605 case EV_ACT_DEASSERTED:
606 bdata->wakeup_trigger_type = active_low ?
607 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
608 break;
609 case EV_ACT_ANY:
610 default:
611 /*
612 * For other cases, we are OK letting suspend/resume
613 * not reconfigure the trigger type.
614 */
615 break;
616 }
617 } else {
618 if (!button->irq) {
619 dev_err(dev, "Found button without gpio or irq\n");
620 return -EINVAL;
621 }
622
623 bdata->irq = button->irq;
624
625 if (button->type && button->type != EV_KEY) {
626 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
627 return -EINVAL;
628 }
629
630 bdata->release_delay = button->debounce_interval;
631 hrtimer_init(&bdata->release_timer,
632 CLOCK_REALTIME, HRTIMER_MODE_REL_HARD);
633 bdata->release_timer.function = gpio_keys_irq_timer;
634
635 isr = gpio_keys_irq_isr;
636 irqflags = 0;
637
638 /*
639 * For IRQ buttons, there is no interrupt for release.
640 * So we don't need to reconfigure the trigger type for wakeup.
641 */
642 }
643
644 bdata->code = &ddata->keymap[idx];
645 *bdata->code = button->code;
646 input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
647
648 /*
649 * Install custom action to cancel release timer and
650 * workqueue item.
651 */
652 error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
653 if (error) {
654 dev_err(dev, "failed to register quiesce action, error: %d\n",
655 error);
656 return error;
657 }
658
659 /*
660 * If platform has specified that the button can be disabled,
661 * we don't want it to share the interrupt line.
662 */
663 if (!button->can_disable)
664 irqflags |= IRQF_SHARED;
665
666 error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
667 desc, bdata);
668 if (error < 0) {
669 dev_err(dev, "Unable to claim irq %d; error %d\n",
670 bdata->irq, error);
671 return error;
672 }
673
674 if (!button->wakeirq)
675 return 0;
676
677 /* Use :wakeup suffix like drivers/base/power/wakeirq.c does */
678 wakedesc = devm_kasprintf(dev, GFP_KERNEL, "%s:wakeup", desc);
679 if (!wakedesc)
680 return -ENOMEM;
681
682 bdata->wakeirq = button->wakeirq;
683 irqflags |= IRQF_NO_SUSPEND;
684
685 /*
686 * Wakeirq shares the handler with the main interrupt, it's only
687 * active during system suspend. See gpio_keys_button_enable_wakeup()
688 * and gpio_keys_button_disable_wakeup().
689 */
690 error = devm_request_any_context_irq(dev, bdata->wakeirq, isr,
691 irqflags, wakedesc, bdata);
692 if (error < 0) {
693 dev_err(dev, "Unable to claim wakeirq %d; error %d\n",
694 bdata->irq, error);
695 return error;
696 }
697
698 /*
699 * Disable wakeirq until suspend. IRQF_NO_AUTOEN won't work if
700 * IRQF_SHARED was set based on !button->can_disable.
701 */
702 disable_irq(bdata->wakeirq);
703
704 return 0;
705}
706
707static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
708{
709 struct input_dev *input = ddata->input;
710 int i;
711
712 for (i = 0; i < ddata->pdata->nbuttons; i++) {
713 struct gpio_button_data *bdata = &ddata->data[i];
714 if (bdata->gpiod)
715 gpio_keys_gpio_report_event(bdata);
716 }
717 input_sync(input);
718}
719
720static int gpio_keys_open(struct input_dev *input)
721{
722 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
723 const struct gpio_keys_platform_data *pdata = ddata->pdata;
724 int error;
725
726 if (pdata->enable) {
727 error = pdata->enable(input->dev.parent);
728 if (error)
729 return error;
730 }
731
732 /* Report current state of buttons that are connected to GPIOs */
733 gpio_keys_report_state(ddata);
734
735 return 0;
736}
737
738static void gpio_keys_close(struct input_dev *input)
739{
740 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
741 const struct gpio_keys_platform_data *pdata = ddata->pdata;
742
743 if (pdata->disable)
744 pdata->disable(input->dev.parent);
745}
746
747/*
748 * Handlers for alternative sources of platform_data
749 */
750
751/*
752 * Translate properties into platform_data
753 */
754static struct gpio_keys_platform_data *
755gpio_keys_get_devtree_pdata(struct device *dev)
756{
757 struct gpio_keys_platform_data *pdata;
758 struct gpio_keys_button *button;
759 int nbuttons, irq;
760
761 nbuttons = device_get_child_node_count(dev);
762 if (nbuttons == 0)
763 return ERR_PTR(-ENODEV);
764
765 pdata = devm_kzalloc(dev,
766 sizeof(*pdata) + nbuttons * sizeof(*button),
767 GFP_KERNEL);
768 if (!pdata)
769 return ERR_PTR(-ENOMEM);
770
771 button = (struct gpio_keys_button *)(pdata + 1);
772
773 pdata->buttons = button;
774 pdata->nbuttons = nbuttons;
775
776 pdata->rep = device_property_read_bool(dev, "autorepeat");
777
778 device_property_read_string(dev, "label", &pdata->name);
779
780 device_for_each_child_node_scoped(dev, child) {
781 if (is_of_node(child)) {
782 irq = of_irq_get_byname(to_of_node(child), "irq");
783 if (irq > 0)
784 button->irq = irq;
785
786 irq = of_irq_get_byname(to_of_node(child), "wakeup");
787 if (irq > 0)
788 button->wakeirq = irq;
789
790 if (!button->irq && !button->wakeirq)
791 button->irq =
792 irq_of_parse_and_map(to_of_node(child), 0);
793 }
794
795 if (fwnode_property_read_u32(child, "linux,code",
796 &button->code)) {
797 dev_err(dev, "Button without keycode\n");
798 return ERR_PTR(-EINVAL);
799 }
800
801 fwnode_property_read_string(child, "label", &button->desc);
802
803 if (fwnode_property_read_u32(child, "linux,input-type",
804 &button->type))
805 button->type = EV_KEY;
806
807 fwnode_property_read_u32(child, "linux,input-value",
808 (u32 *)&button->value);
809
810 button->wakeup =
811 fwnode_property_read_bool(child, "wakeup-source") ||
812 /* legacy name */
813 fwnode_property_read_bool(child, "gpio-key,wakeup");
814
815 fwnode_property_read_u32(child, "wakeup-event-action",
816 &button->wakeup_event_action);
817
818 button->can_disable =
819 fwnode_property_read_bool(child, "linux,can-disable");
820
821 if (fwnode_property_read_u32(child, "debounce-interval",
822 &button->debounce_interval))
823 button->debounce_interval = 5;
824
825 button++;
826 }
827
828 return pdata;
829}
830
831static const struct of_device_id gpio_keys_of_match[] = {
832 { .compatible = "gpio-keys", },
833 { },
834};
835MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
836
837static int gpio_keys_probe(struct platform_device *pdev)
838{
839 struct device *dev = &pdev->dev;
840 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
841 struct fwnode_handle *child = NULL;
842 struct gpio_keys_drvdata *ddata;
843 struct input_dev *input;
844 int i, error;
845 int wakeup = 0;
846
847 if (!pdata) {
848 pdata = gpio_keys_get_devtree_pdata(dev);
849 if (IS_ERR(pdata))
850 return PTR_ERR(pdata);
851 }
852
853 ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
854 GFP_KERNEL);
855 if (!ddata) {
856 dev_err(dev, "failed to allocate state\n");
857 return -ENOMEM;
858 }
859
860 ddata->keymap = devm_kcalloc(dev,
861 pdata->nbuttons, sizeof(ddata->keymap[0]),
862 GFP_KERNEL);
863 if (!ddata->keymap)
864 return -ENOMEM;
865
866 input = devm_input_allocate_device(dev);
867 if (!input) {
868 dev_err(dev, "failed to allocate input device\n");
869 return -ENOMEM;
870 }
871
872 ddata->pdata = pdata;
873 ddata->input = input;
874 mutex_init(&ddata->disable_lock);
875
876 platform_set_drvdata(pdev, ddata);
877 input_set_drvdata(input, ddata);
878
879 input->name = pdata->name ? : pdev->name;
880 input->phys = "gpio-keys/input0";
881 input->dev.parent = dev;
882 input->open = gpio_keys_open;
883 input->close = gpio_keys_close;
884
885 input->id.bustype = BUS_HOST;
886 input->id.vendor = 0x0001;
887 input->id.product = 0x0001;
888 input->id.version = 0x0100;
889
890 input->keycode = ddata->keymap;
891 input->keycodesize = sizeof(ddata->keymap[0]);
892 input->keycodemax = pdata->nbuttons;
893
894 /* Enable auto repeat feature of Linux input subsystem */
895 if (pdata->rep)
896 __set_bit(EV_REP, input->evbit);
897
898 for (i = 0; i < pdata->nbuttons; i++) {
899 const struct gpio_keys_button *button = &pdata->buttons[i];
900
901 if (!dev_get_platdata(dev)) {
902 child = device_get_next_child_node(dev, child);
903 if (!child) {
904 dev_err(dev,
905 "missing child device node for entry %d\n",
906 i);
907 return -EINVAL;
908 }
909 }
910
911 error = gpio_keys_setup_key(pdev, input, ddata,
912 button, i, child);
913 if (error) {
914 fwnode_handle_put(child);
915 return error;
916 }
917
918 if (button->wakeup)
919 wakeup = 1;
920 }
921
922 fwnode_handle_put(child);
923
924 error = input_register_device(input);
925 if (error) {
926 dev_err(dev, "Unable to register input device, error: %d\n",
927 error);
928 return error;
929 }
930
931 device_init_wakeup(dev, wakeup);
932
933 return 0;
934}
935
936static int __maybe_unused
937gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
938{
939 int error;
940
941 error = enable_irq_wake(bdata->irq);
942 if (error) {
943 dev_err(bdata->input->dev.parent,
944 "failed to configure IRQ %d as wakeup source: %d\n",
945 bdata->irq, error);
946 return error;
947 }
948
949 if (bdata->wakeup_trigger_type) {
950 error = irq_set_irq_type(bdata->irq,
951 bdata->wakeup_trigger_type);
952 if (error) {
953 dev_err(bdata->input->dev.parent,
954 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
955 bdata->wakeup_trigger_type, bdata->irq, error);
956 disable_irq_wake(bdata->irq);
957 return error;
958 }
959 }
960
961 if (bdata->wakeirq) {
962 enable_irq(bdata->wakeirq);
963 disable_irq(bdata->irq);
964 }
965
966 return 0;
967}
968
969static void __maybe_unused
970gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
971{
972 int error;
973
974 if (bdata->wakeirq) {
975 enable_irq(bdata->irq);
976 disable_irq(bdata->wakeirq);
977 }
978
979 /*
980 * The trigger type is always both edges for gpio-based keys and we do
981 * not support changing wakeup trigger for interrupt-based keys.
982 */
983 if (bdata->wakeup_trigger_type) {
984 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
985 if (error)
986 dev_warn(bdata->input->dev.parent,
987 "failed to restore interrupt trigger for IRQ %d: %d\n",
988 bdata->irq, error);
989 }
990
991 error = disable_irq_wake(bdata->irq);
992 if (error)
993 dev_warn(bdata->input->dev.parent,
994 "failed to disable IRQ %d as wake source: %d\n",
995 bdata->irq, error);
996}
997
998static int __maybe_unused
999gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
1000{
1001 struct gpio_button_data *bdata;
1002 int error;
1003 int i;
1004
1005 for (i = 0; i < ddata->pdata->nbuttons; i++) {
1006 bdata = &ddata->data[i];
1007 if (bdata->button->wakeup) {
1008 error = gpio_keys_button_enable_wakeup(bdata);
1009 if (error)
1010 goto err_out;
1011 }
1012 bdata->suspended = true;
1013 }
1014
1015 return 0;
1016
1017err_out:
1018 while (i--) {
1019 bdata = &ddata->data[i];
1020 if (bdata->button->wakeup)
1021 gpio_keys_button_disable_wakeup(bdata);
1022 bdata->suspended = false;
1023 }
1024
1025 return error;
1026}
1027
1028static void __maybe_unused
1029gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
1030{
1031 struct gpio_button_data *bdata;
1032 int i;
1033
1034 for (i = 0; i < ddata->pdata->nbuttons; i++) {
1035 bdata = &ddata->data[i];
1036 bdata->suspended = false;
1037 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
1038 gpio_keys_button_disable_wakeup(bdata);
1039 }
1040}
1041
1042static int gpio_keys_suspend(struct device *dev)
1043{
1044 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
1045 struct input_dev *input = ddata->input;
1046 int error;
1047
1048 if (device_may_wakeup(dev)) {
1049 error = gpio_keys_enable_wakeup(ddata);
1050 if (error)
1051 return error;
1052 } else {
1053 guard(mutex)(&input->mutex);
1054
1055 if (input_device_enabled(input))
1056 gpio_keys_close(input);
1057 }
1058
1059 return 0;
1060}
1061
1062static int gpio_keys_resume(struct device *dev)
1063{
1064 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
1065 struct input_dev *input = ddata->input;
1066 int error;
1067
1068 if (device_may_wakeup(dev)) {
1069 gpio_keys_disable_wakeup(ddata);
1070 } else {
1071 guard(mutex)(&input->mutex);
1072
1073 if (input_device_enabled(input)) {
1074 error = gpio_keys_open(input);
1075 if (error)
1076 return error;
1077 }
1078 }
1079
1080 gpio_keys_report_state(ddata);
1081 return 0;
1082}
1083
1084static DEFINE_SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1085
1086static void gpio_keys_shutdown(struct platform_device *pdev)
1087{
1088 int ret;
1089
1090 ret = gpio_keys_suspend(&pdev->dev);
1091 if (ret)
1092 dev_err(&pdev->dev, "failed to shutdown\n");
1093}
1094
1095static struct platform_driver gpio_keys_device_driver = {
1096 .probe = gpio_keys_probe,
1097 .shutdown = gpio_keys_shutdown,
1098 .driver = {
1099 .name = "gpio-keys",
1100 .pm = pm_sleep_ptr(&gpio_keys_pm_ops),
1101 .of_match_table = gpio_keys_of_match,
1102 .dev_groups = gpio_keys_groups,
1103 }
1104};
1105
1106static int __init gpio_keys_init(void)
1107{
1108 return platform_driver_register(&gpio_keys_device_driver);
1109}
1110
1111static void __exit gpio_keys_exit(void)
1112{
1113 platform_driver_unregister(&gpio_keys_device_driver);
1114}
1115
1116late_initcall(gpio_keys_init);
1117module_exit(gpio_keys_exit);
1118
1119MODULE_LICENSE("GPL");
1120MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1121MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1122MODULE_ALIAS("platform:gpio-keys");
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
34struct gpio_button_data {
35 const struct gpio_keys_button *button;
36 struct input_dev *input;
37 struct gpio_desc *gpiod;
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
51struct 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 */
99static 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 */
114static 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 */
135static 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 (bdata->gpiod)
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 */
162static 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 */
184static 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 */
228static 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
280out:
281 kfree(bits);
282 return error;
283}
284
285#define ATTR_SHOW_FN(name, type, only_disabled) \
286static 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
297ATTR_SHOW_FN(keys, EV_KEY, false);
298ATTR_SHOW_FN(switches, EV_SW, false);
299ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
300ATTR_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 */
308static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
309static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
310
311#define ATTR_STORE_FN(name, type) \
312static 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
328ATTR_STORE_FN(disabled_keys, EV_KEY);
329ATTR_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 */
337static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
338 gpio_keys_show_disabled_keys,
339 gpio_keys_store_disabled_keys);
340static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
341 gpio_keys_show_disabled_switches,
342 gpio_keys_store_disabled_switches);
343
344static 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
352static struct attribute_group gpio_keys_attr_group = {
353 .attrs = gpio_keys_attrs,
354};
355
356static 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;
362
363 state = gpiod_get_value_cansleep(bdata->gpiod);
364 if (state < 0) {
365 dev_err(input->dev.parent,
366 "failed to get gpio state: %d\n", state);
367 return;
368 }
369
370 if (type == EV_ABS) {
371 if (state)
372 input_event(input, type, button->code, button->value);
373 } else {
374 input_event(input, type, button->code, state);
375 }
376 input_sync(input);
377}
378
379static void gpio_keys_gpio_work_func(struct work_struct *work)
380{
381 struct gpio_button_data *bdata =
382 container_of(work, struct gpio_button_data, work.work);
383
384 gpio_keys_gpio_report_event(bdata);
385
386 if (bdata->button->wakeup)
387 pm_relax(bdata->input->dev.parent);
388}
389
390static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
391{
392 struct gpio_button_data *bdata = dev_id;
393
394 BUG_ON(irq != bdata->irq);
395
396 if (bdata->button->wakeup)
397 pm_stay_awake(bdata->input->dev.parent);
398
399 mod_delayed_work(system_wq,
400 &bdata->work,
401 msecs_to_jiffies(bdata->software_debounce));
402
403 return IRQ_HANDLED;
404}
405
406static void gpio_keys_irq_timer(unsigned long _data)
407{
408 struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
409 struct input_dev *input = bdata->input;
410 unsigned long flags;
411
412 spin_lock_irqsave(&bdata->lock, flags);
413 if (bdata->key_pressed) {
414 input_event(input, EV_KEY, bdata->button->code, 0);
415 input_sync(input);
416 bdata->key_pressed = false;
417 }
418 spin_unlock_irqrestore(&bdata->lock, flags);
419}
420
421static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
422{
423 struct gpio_button_data *bdata = dev_id;
424 const struct gpio_keys_button *button = bdata->button;
425 struct input_dev *input = bdata->input;
426 unsigned long flags;
427
428 BUG_ON(irq != bdata->irq);
429
430 spin_lock_irqsave(&bdata->lock, flags);
431
432 if (!bdata->key_pressed) {
433 if (bdata->button->wakeup)
434 pm_wakeup_event(bdata->input->dev.parent, 0);
435
436 input_event(input, EV_KEY, button->code, 1);
437 input_sync(input);
438
439 if (!bdata->release_delay) {
440 input_event(input, EV_KEY, button->code, 0);
441 input_sync(input);
442 goto out;
443 }
444
445 bdata->key_pressed = true;
446 }
447
448 if (bdata->release_delay)
449 mod_timer(&bdata->release_timer,
450 jiffies + msecs_to_jiffies(bdata->release_delay));
451out:
452 spin_unlock_irqrestore(&bdata->lock, flags);
453 return IRQ_HANDLED;
454}
455
456static void gpio_keys_quiesce_key(void *data)
457{
458 struct gpio_button_data *bdata = data;
459
460 if (bdata->gpiod)
461 cancel_delayed_work_sync(&bdata->work);
462 else
463 del_timer_sync(&bdata->release_timer);
464}
465
466static int gpio_keys_setup_key(struct platform_device *pdev,
467 struct input_dev *input,
468 struct gpio_button_data *bdata,
469 const struct gpio_keys_button *button,
470 struct fwnode_handle *child)
471{
472 const char *desc = button->desc ? button->desc : "gpio_keys";
473 struct device *dev = &pdev->dev;
474 irq_handler_t isr;
475 unsigned long irqflags;
476 int irq;
477 int error;
478
479 bdata->input = input;
480 bdata->button = button;
481 spin_lock_init(&bdata->lock);
482
483 if (child) {
484 bdata->gpiod = devm_get_gpiod_from_child(dev, NULL, child);
485 if (IS_ERR(bdata->gpiod)) {
486 error = PTR_ERR(bdata->gpiod);
487 if (error == -ENOENT) {
488 /*
489 * GPIO is optional, we may be dealing with
490 * purely interrupt-driven setup.
491 */
492 bdata->gpiod = NULL;
493 } else {
494 if (error != -EPROBE_DEFER)
495 dev_err(dev, "failed to get gpio: %d\n",
496 error);
497 return error;
498 }
499 } else {
500 error = gpiod_direction_input(bdata->gpiod);
501 if (error) {
502 dev_err(dev, "Failed to configure GPIO %d as input: %d\n",
503 desc_to_gpio(bdata->gpiod), error);
504 return error;
505 }
506 }
507 } else if (gpio_is_valid(button->gpio)) {
508 /*
509 * Legacy GPIO number, so request the GPIO here and
510 * convert it to descriptor.
511 */
512 unsigned flags = GPIOF_IN;
513
514 if (button->active_low)
515 flags |= GPIOF_ACTIVE_LOW;
516
517 error = devm_gpio_request_one(&pdev->dev, button->gpio, flags,
518 desc);
519 if (error < 0) {
520 dev_err(dev, "Failed to request GPIO %d, error %d\n",
521 button->gpio, error);
522 return error;
523 }
524
525 bdata->gpiod = gpio_to_desc(button->gpio);
526 if (!bdata->gpiod)
527 return -EINVAL;
528 }
529
530 if (bdata->gpiod) {
531 if (button->debounce_interval) {
532 error = gpiod_set_debounce(bdata->gpiod,
533 button->debounce_interval * 1000);
534 /* use timer if gpiolib doesn't provide debounce */
535 if (error < 0)
536 bdata->software_debounce =
537 button->debounce_interval;
538 }
539
540 if (button->irq) {
541 bdata->irq = button->irq;
542 } else {
543 irq = gpiod_to_irq(bdata->gpiod);
544 if (irq < 0) {
545 error = irq;
546 dev_err(dev,
547 "Unable to get irq number for GPIO %d, error %d\n",
548 button->gpio, error);
549 return error;
550 }
551 bdata->irq = irq;
552 }
553
554 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
555
556 isr = gpio_keys_gpio_isr;
557 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
558
559 } else {
560 if (!button->irq) {
561 dev_err(dev, "Found button without gpio or irq\n");
562 return -EINVAL;
563 }
564
565 bdata->irq = button->irq;
566
567 if (button->type && button->type != EV_KEY) {
568 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
569 return -EINVAL;
570 }
571
572 bdata->release_delay = button->debounce_interval;
573 setup_timer(&bdata->release_timer,
574 gpio_keys_irq_timer, (unsigned long)bdata);
575
576 isr = gpio_keys_irq_isr;
577 irqflags = 0;
578 }
579
580 input_set_capability(input, button->type ?: EV_KEY, button->code);
581
582 /*
583 * Install custom action to cancel release timer and
584 * workqueue item.
585 */
586 error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
587 if (error) {
588 dev_err(&pdev->dev,
589 "failed to register quiesce action, error: %d\n",
590 error);
591 return error;
592 }
593
594 /*
595 * If platform has specified that the button can be disabled,
596 * we don't want it to share the interrupt line.
597 */
598 if (!button->can_disable)
599 irqflags |= IRQF_SHARED;
600
601 error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
602 isr, irqflags, desc, bdata);
603 if (error < 0) {
604 dev_err(dev, "Unable to claim irq %d; error %d\n",
605 bdata->irq, error);
606 return error;
607 }
608
609 return 0;
610}
611
612static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
613{
614 struct input_dev *input = ddata->input;
615 int i;
616
617 for (i = 0; i < ddata->pdata->nbuttons; i++) {
618 struct gpio_button_data *bdata = &ddata->data[i];
619 if (bdata->gpiod)
620 gpio_keys_gpio_report_event(bdata);
621 }
622 input_sync(input);
623}
624
625static int gpio_keys_open(struct input_dev *input)
626{
627 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
628 const struct gpio_keys_platform_data *pdata = ddata->pdata;
629 int error;
630
631 if (pdata->enable) {
632 error = pdata->enable(input->dev.parent);
633 if (error)
634 return error;
635 }
636
637 /* Report current state of buttons that are connected to GPIOs */
638 gpio_keys_report_state(ddata);
639
640 return 0;
641}
642
643static void gpio_keys_close(struct input_dev *input)
644{
645 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
646 const struct gpio_keys_platform_data *pdata = ddata->pdata;
647
648 if (pdata->disable)
649 pdata->disable(input->dev.parent);
650}
651
652/*
653 * Handlers for alternative sources of platform_data
654 */
655
656/*
657 * Translate properties into platform_data
658 */
659static struct gpio_keys_platform_data *
660gpio_keys_get_devtree_pdata(struct device *dev)
661{
662 struct gpio_keys_platform_data *pdata;
663 struct gpio_keys_button *button;
664 struct fwnode_handle *child;
665 int nbuttons;
666
667 nbuttons = device_get_child_node_count(dev);
668 if (nbuttons == 0)
669 return ERR_PTR(-ENODEV);
670
671 pdata = devm_kzalloc(dev,
672 sizeof(*pdata) + nbuttons * sizeof(*button),
673 GFP_KERNEL);
674 if (!pdata)
675 return ERR_PTR(-ENOMEM);
676
677 button = (struct gpio_keys_button *)(pdata + 1);
678
679 pdata->buttons = button;
680 pdata->nbuttons = nbuttons;
681
682 pdata->rep = device_property_read_bool(dev, "autorepeat");
683
684 device_property_read_string(dev, "label", &pdata->name);
685
686 device_for_each_child_node(dev, child) {
687 if (is_of_node(child))
688 button->irq =
689 irq_of_parse_and_map(to_of_node(child), 0);
690
691 if (fwnode_property_read_u32(child, "linux,code",
692 &button->code)) {
693 dev_err(dev, "Button without keycode\n");
694 fwnode_handle_put(child);
695 return ERR_PTR(-EINVAL);
696 }
697
698 fwnode_property_read_string(child, "label", &button->desc);
699
700 if (fwnode_property_read_u32(child, "linux,input-type",
701 &button->type))
702 button->type = EV_KEY;
703
704 button->wakeup =
705 fwnode_property_read_bool(child, "wakeup-source") ||
706 /* legacy name */
707 fwnode_property_read_bool(child, "gpio-key,wakeup");
708
709 button->can_disable =
710 fwnode_property_read_bool(child, "linux,can-disable");
711
712 if (fwnode_property_read_u32(child, "debounce-interval",
713 &button->debounce_interval))
714 button->debounce_interval = 5;
715
716 button++;
717 }
718
719 return pdata;
720}
721
722static const struct of_device_id gpio_keys_of_match[] = {
723 { .compatible = "gpio-keys", },
724 { },
725};
726MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
727
728static int gpio_keys_probe(struct platform_device *pdev)
729{
730 struct device *dev = &pdev->dev;
731 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
732 struct fwnode_handle *child = NULL;
733 struct gpio_keys_drvdata *ddata;
734 struct input_dev *input;
735 size_t size;
736 int i, error;
737 int wakeup = 0;
738
739 if (!pdata) {
740 pdata = gpio_keys_get_devtree_pdata(dev);
741 if (IS_ERR(pdata))
742 return PTR_ERR(pdata);
743 }
744
745 size = sizeof(struct gpio_keys_drvdata) +
746 pdata->nbuttons * sizeof(struct gpio_button_data);
747 ddata = devm_kzalloc(dev, size, GFP_KERNEL);
748 if (!ddata) {
749 dev_err(dev, "failed to allocate state\n");
750 return -ENOMEM;
751 }
752
753 input = devm_input_allocate_device(dev);
754 if (!input) {
755 dev_err(dev, "failed to allocate input device\n");
756 return -ENOMEM;
757 }
758
759 ddata->pdata = pdata;
760 ddata->input = input;
761 mutex_init(&ddata->disable_lock);
762
763 platform_set_drvdata(pdev, ddata);
764 input_set_drvdata(input, ddata);
765
766 input->name = pdata->name ? : pdev->name;
767 input->phys = "gpio-keys/input0";
768 input->dev.parent = &pdev->dev;
769 input->open = gpio_keys_open;
770 input->close = gpio_keys_close;
771
772 input->id.bustype = BUS_HOST;
773 input->id.vendor = 0x0001;
774 input->id.product = 0x0001;
775 input->id.version = 0x0100;
776
777 /* Enable auto repeat feature of Linux input subsystem */
778 if (pdata->rep)
779 __set_bit(EV_REP, input->evbit);
780
781 for (i = 0; i < pdata->nbuttons; i++) {
782 const struct gpio_keys_button *button = &pdata->buttons[i];
783 struct gpio_button_data *bdata = &ddata->data[i];
784
785 if (!dev_get_platdata(dev)) {
786 child = device_get_next_child_node(&pdev->dev, child);
787 if (!child) {
788 dev_err(&pdev->dev,
789 "missing child device node for entry %d\n",
790 i);
791 return -EINVAL;
792 }
793 }
794
795 error = gpio_keys_setup_key(pdev, input, bdata, button, child);
796 if (error) {
797 fwnode_handle_put(child);
798 return error;
799 }
800
801 if (button->wakeup)
802 wakeup = 1;
803 }
804
805 fwnode_handle_put(child);
806
807 error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
808 if (error) {
809 dev_err(dev, "Unable to export keys/switches, error: %d\n",
810 error);
811 return error;
812 }
813
814 error = input_register_device(input);
815 if (error) {
816 dev_err(dev, "Unable to register input device, error: %d\n",
817 error);
818 goto err_remove_group;
819 }
820
821 device_init_wakeup(&pdev->dev, wakeup);
822
823 return 0;
824
825err_remove_group:
826 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
827 return error;
828}
829
830static int gpio_keys_remove(struct platform_device *pdev)
831{
832 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
833
834 device_init_wakeup(&pdev->dev, 0);
835
836 return 0;
837}
838
839static int __maybe_unused gpio_keys_suspend(struct device *dev)
840{
841 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
842 struct input_dev *input = ddata->input;
843 int i;
844
845 if (device_may_wakeup(dev)) {
846 for (i = 0; i < ddata->pdata->nbuttons; i++) {
847 struct gpio_button_data *bdata = &ddata->data[i];
848 if (bdata->button->wakeup)
849 enable_irq_wake(bdata->irq);
850 }
851 } else {
852 mutex_lock(&input->mutex);
853 if (input->users)
854 gpio_keys_close(input);
855 mutex_unlock(&input->mutex);
856 }
857
858 return 0;
859}
860
861static int __maybe_unused gpio_keys_resume(struct device *dev)
862{
863 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
864 struct input_dev *input = ddata->input;
865 int error = 0;
866 int i;
867
868 if (device_may_wakeup(dev)) {
869 for (i = 0; i < ddata->pdata->nbuttons; i++) {
870 struct gpio_button_data *bdata = &ddata->data[i];
871 if (bdata->button->wakeup)
872 disable_irq_wake(bdata->irq);
873 }
874 } else {
875 mutex_lock(&input->mutex);
876 if (input->users)
877 error = gpio_keys_open(input);
878 mutex_unlock(&input->mutex);
879 }
880
881 if (error)
882 return error;
883
884 gpio_keys_report_state(ddata);
885 return 0;
886}
887
888static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
889
890static struct platform_driver gpio_keys_device_driver = {
891 .probe = gpio_keys_probe,
892 .remove = gpio_keys_remove,
893 .driver = {
894 .name = "gpio-keys",
895 .pm = &gpio_keys_pm_ops,
896 .of_match_table = gpio_keys_of_match,
897 }
898};
899
900static int __init gpio_keys_init(void)
901{
902 return platform_driver_register(&gpio_keys_device_driver);
903}
904
905static void __exit gpio_keys_exit(void)
906{
907 platform_driver_unregister(&gpio_keys_device_driver);
908}
909
910late_initcall(gpio_keys_init);
911module_exit(gpio_keys_exit);
912
913MODULE_LICENSE("GPL");
914MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
915MODULE_DESCRIPTION("Keyboard driver for GPIOs");
916MODULE_ALIAS("platform:gpio-keys");