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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 unsigned long *bits;
249 ssize_t error;
250 int i;
251
252 bits = bitmap_alloc(n_events, GFP_KERNEL);
253 if (!bits)
254 return -ENOMEM;
255
256 error = bitmap_parselist(buf, bits, n_events);
257 if (error)
258 goto out;
259
260 /* First validate */
261 if (!bitmap_subset(bits, bitmap, n_events)) {
262 error = -EINVAL;
263 goto out;
264 }
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->code, bits) &&
273 !bdata->button->can_disable) {
274 error = -EINVAL;
275 goto out;
276 }
277 }
278
279 mutex_lock(&ddata->disable_lock);
280
281 for (i = 0; i < ddata->pdata->nbuttons; i++) {
282 struct gpio_button_data *bdata = &ddata->data[i];
283
284 if (bdata->button->type != type)
285 continue;
286
287 if (test_bit(*bdata->code, bits))
288 gpio_keys_disable_button(bdata);
289 else
290 gpio_keys_enable_button(bdata);
291 }
292
293 mutex_unlock(&ddata->disable_lock);
294
295out:
296 bitmap_free(bits);
297 return error;
298}
299
300#define ATTR_SHOW_FN(name, type, only_disabled) \
301static ssize_t gpio_keys_show_##name(struct device *dev, \
302 struct device_attribute *attr, \
303 char *buf) \
304{ \
305 struct platform_device *pdev = to_platform_device(dev); \
306 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
307 \
308 return gpio_keys_attr_show_helper(ddata, buf, \
309 type, only_disabled); \
310}
311
312ATTR_SHOW_FN(keys, EV_KEY, false);
313ATTR_SHOW_FN(switches, EV_SW, false);
314ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
315ATTR_SHOW_FN(disabled_switches, EV_SW, true);
316
317/*
318 * ATTRIBUTES:
319 *
320 * /sys/devices/platform/gpio-keys/keys [ro]
321 * /sys/devices/platform/gpio-keys/switches [ro]
322 */
323static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
324static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
325
326#define ATTR_STORE_FN(name, type) \
327static ssize_t gpio_keys_store_##name(struct device *dev, \
328 struct device_attribute *attr, \
329 const char *buf, \
330 size_t count) \
331{ \
332 struct platform_device *pdev = to_platform_device(dev); \
333 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
334 ssize_t error; \
335 \
336 error = gpio_keys_attr_store_helper(ddata, buf, type); \
337 if (error) \
338 return error; \
339 \
340 return count; \
341}
342
343ATTR_STORE_FN(disabled_keys, EV_KEY);
344ATTR_STORE_FN(disabled_switches, EV_SW);
345
346/*
347 * ATTRIBUTES:
348 *
349 * /sys/devices/platform/gpio-keys/disabled_keys [rw]
350 * /sys/devices/platform/gpio-keys/disables_switches [rw]
351 */
352static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
353 gpio_keys_show_disabled_keys,
354 gpio_keys_store_disabled_keys);
355static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
356 gpio_keys_show_disabled_switches,
357 gpio_keys_store_disabled_switches);
358
359static struct attribute *gpio_keys_attrs[] = {
360 &dev_attr_keys.attr,
361 &dev_attr_switches.attr,
362 &dev_attr_disabled_keys.attr,
363 &dev_attr_disabled_switches.attr,
364 NULL,
365};
366ATTRIBUTE_GROUPS(gpio_keys);
367
368static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
369{
370 const struct gpio_keys_button *button = bdata->button;
371 struct input_dev *input = bdata->input;
372 unsigned int type = button->type ?: EV_KEY;
373 int state;
374
375 state = bdata->debounce_use_hrtimer ?
376 gpiod_get_value(bdata->gpiod) :
377 gpiod_get_value_cansleep(bdata->gpiod);
378 if (state < 0) {
379 dev_err(input->dev.parent,
380 "failed to get gpio state: %d\n", state);
381 return;
382 }
383
384 if (type == EV_ABS) {
385 if (state)
386 input_event(input, type, button->code, button->value);
387 } else {
388 input_event(input, type, *bdata->code, state);
389 }
390}
391
392static void gpio_keys_debounce_event(struct gpio_button_data *bdata)
393{
394 gpio_keys_gpio_report_event(bdata);
395 input_sync(bdata->input);
396
397 if (bdata->button->wakeup)
398 pm_relax(bdata->input->dev.parent);
399}
400
401static void gpio_keys_gpio_work_func(struct work_struct *work)
402{
403 struct gpio_button_data *bdata =
404 container_of(work, struct gpio_button_data, work.work);
405
406 gpio_keys_debounce_event(bdata);
407}
408
409static enum hrtimer_restart gpio_keys_debounce_timer(struct hrtimer *t)
410{
411 struct gpio_button_data *bdata =
412 container_of(t, struct gpio_button_data, debounce_timer);
413
414 gpio_keys_debounce_event(bdata);
415
416 return HRTIMER_NORESTART;
417}
418
419static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
420{
421 struct gpio_button_data *bdata = dev_id;
422
423 BUG_ON(irq != bdata->irq);
424
425 if (bdata->button->wakeup) {
426 const struct gpio_keys_button *button = bdata->button;
427
428 pm_stay_awake(bdata->input->dev.parent);
429 if (bdata->suspended &&
430 (button->type == 0 || button->type == EV_KEY)) {
431 /*
432 * Simulate wakeup key press in case the key has
433 * already released by the time we got interrupt
434 * handler to run.
435 */
436 input_report_key(bdata->input, button->code, 1);
437 }
438 }
439
440 if (bdata->debounce_use_hrtimer) {
441 hrtimer_start(&bdata->debounce_timer,
442 ms_to_ktime(bdata->software_debounce),
443 HRTIMER_MODE_REL);
444 } else {
445 mod_delayed_work(system_wq,
446 &bdata->work,
447 msecs_to_jiffies(bdata->software_debounce));
448 }
449
450 return IRQ_HANDLED;
451}
452
453static enum hrtimer_restart gpio_keys_irq_timer(struct hrtimer *t)
454{
455 struct gpio_button_data *bdata = container_of(t,
456 struct gpio_button_data,
457 release_timer);
458 struct input_dev *input = bdata->input;
459
460 if (bdata->key_pressed) {
461 input_report_key(input, *bdata->code, 0);
462 input_sync(input);
463 bdata->key_pressed = false;
464 }
465
466 return HRTIMER_NORESTART;
467}
468
469static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
470{
471 struct gpio_button_data *bdata = dev_id;
472 struct input_dev *input = bdata->input;
473 unsigned long flags;
474
475 BUG_ON(irq != bdata->irq);
476
477 spin_lock_irqsave(&bdata->lock, flags);
478
479 if (!bdata->key_pressed) {
480 if (bdata->button->wakeup)
481 pm_wakeup_event(bdata->input->dev.parent, 0);
482
483 input_report_key(input, *bdata->code, 1);
484 input_sync(input);
485
486 if (!bdata->release_delay) {
487 input_report_key(input, *bdata->code, 0);
488 input_sync(input);
489 goto out;
490 }
491
492 bdata->key_pressed = true;
493 }
494
495 if (bdata->release_delay)
496 hrtimer_start(&bdata->release_timer,
497 ms_to_ktime(bdata->release_delay),
498 HRTIMER_MODE_REL_HARD);
499out:
500 spin_unlock_irqrestore(&bdata->lock, flags);
501 return IRQ_HANDLED;
502}
503
504static int gpio_keys_setup_key(struct platform_device *pdev,
505 struct input_dev *input,
506 struct gpio_keys_drvdata *ddata,
507 const struct gpio_keys_button *button,
508 int idx,
509 struct fwnode_handle *child)
510{
511 const char *desc = button->desc ? button->desc : "gpio_keys";
512 struct device *dev = &pdev->dev;
513 struct gpio_button_data *bdata = &ddata->data[idx];
514 irq_handler_t isr;
515 unsigned long irqflags;
516 const char *wakedesc;
517 int irq;
518 int error;
519
520 bdata->input = input;
521 bdata->button = button;
522 spin_lock_init(&bdata->lock);
523
524 if (child) {
525 bdata->gpiod = devm_fwnode_gpiod_get(dev, child,
526 NULL, GPIOD_IN, desc);
527 if (IS_ERR(bdata->gpiod)) {
528 error = PTR_ERR(bdata->gpiod);
529 if (error != -ENOENT)
530 return dev_err_probe(dev, error,
531 "failed to get gpio\n");
532
533 /*
534 * GPIO is optional, we may be dealing with
535 * purely interrupt-driven setup.
536 */
537 bdata->gpiod = NULL;
538 }
539 } else if (gpio_is_valid(button->gpio)) {
540 /*
541 * Legacy GPIO number, so request the GPIO here and
542 * convert it to descriptor.
543 */
544 unsigned flags = GPIOF_IN;
545
546 if (button->active_low)
547 flags |= GPIOF_ACTIVE_LOW;
548
549 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
550 if (error < 0) {
551 dev_err(dev, "Failed to request GPIO %d, error %d\n",
552 button->gpio, error);
553 return error;
554 }
555
556 bdata->gpiod = gpio_to_desc(button->gpio);
557 if (!bdata->gpiod)
558 return -EINVAL;
559 }
560
561 if (bdata->gpiod) {
562 bool active_low = gpiod_is_active_low(bdata->gpiod);
563
564 if (button->debounce_interval) {
565 error = gpiod_set_debounce(bdata->gpiod,
566 button->debounce_interval * 1000);
567 /* use timer if gpiolib doesn't provide debounce */
568 if (error < 0)
569 bdata->software_debounce =
570 button->debounce_interval;
571
572 /*
573 * If reading the GPIO won't sleep, we can use a
574 * hrtimer instead of a standard timer for the software
575 * debounce, to reduce the latency as much as possible.
576 */
577 bdata->debounce_use_hrtimer =
578 !gpiod_cansleep(bdata->gpiod);
579 }
580
581 /*
582 * If an interrupt was specified, use it instead of the gpio
583 * interrupt and use the gpio for reading the state. A separate
584 * interrupt may be used as the main button interrupt for
585 * runtime PM to detect events also in deeper idle states. If a
586 * dedicated wakeirq is used for system suspend only, see below
587 * for bdata->wakeirq setup.
588 */
589 if (button->irq) {
590 bdata->irq = button->irq;
591 } else {
592 irq = gpiod_to_irq(bdata->gpiod);
593 if (irq < 0) {
594 error = irq;
595 dev_err_probe(dev, error,
596 "Unable to get irq number for GPIO %d\n",
597 button->gpio);
598 return error;
599 }
600 bdata->irq = irq;
601 }
602
603 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
604
605 hrtimer_init(&bdata->debounce_timer,
606 CLOCK_REALTIME, HRTIMER_MODE_REL);
607 bdata->debounce_timer.function = gpio_keys_debounce_timer;
608
609 isr = gpio_keys_gpio_isr;
610 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
611
612 switch (button->wakeup_event_action) {
613 case EV_ACT_ASSERTED:
614 bdata->wakeup_trigger_type = active_low ?
615 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
616 break;
617 case EV_ACT_DEASSERTED:
618 bdata->wakeup_trigger_type = active_low ?
619 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
620 break;
621 case EV_ACT_ANY:
622 default:
623 /*
624 * For other cases, we are OK letting suspend/resume
625 * not reconfigure the trigger type.
626 */
627 break;
628 }
629 } else {
630 if (!button->irq) {
631 dev_err(dev, "Found button without gpio or irq\n");
632 return -EINVAL;
633 }
634
635 bdata->irq = button->irq;
636
637 if (button->type && button->type != EV_KEY) {
638 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
639 return -EINVAL;
640 }
641
642 bdata->release_delay = button->debounce_interval;
643 hrtimer_init(&bdata->release_timer,
644 CLOCK_REALTIME, HRTIMER_MODE_REL_HARD);
645 bdata->release_timer.function = gpio_keys_irq_timer;
646
647 isr = gpio_keys_irq_isr;
648 irqflags = 0;
649
650 /*
651 * For IRQ buttons, there is no interrupt for release.
652 * So we don't need to reconfigure the trigger type for wakeup.
653 */
654 }
655
656 bdata->code = &ddata->keymap[idx];
657 *bdata->code = button->code;
658 input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
659
660 /*
661 * Install custom action to cancel release timer and
662 * workqueue item.
663 */
664 error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
665 if (error) {
666 dev_err(dev, "failed to register quiesce action, error: %d\n",
667 error);
668 return error;
669 }
670
671 /*
672 * If platform has specified that the button can be disabled,
673 * we don't want it to share the interrupt line.
674 */
675 if (!button->can_disable)
676 irqflags |= IRQF_SHARED;
677
678 error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
679 desc, bdata);
680 if (error < 0) {
681 dev_err(dev, "Unable to claim irq %d; error %d\n",
682 bdata->irq, error);
683 return error;
684 }
685
686 if (!button->wakeirq)
687 return 0;
688
689 /* Use :wakeup suffix like drivers/base/power/wakeirq.c does */
690 wakedesc = devm_kasprintf(dev, GFP_KERNEL, "%s:wakeup", desc);
691 if (!wakedesc)
692 return -ENOMEM;
693
694 bdata->wakeirq = button->wakeirq;
695 irqflags |= IRQF_NO_SUSPEND;
696
697 /*
698 * Wakeirq shares the handler with the main interrupt, it's only
699 * active during system suspend. See gpio_keys_button_enable_wakeup()
700 * and gpio_keys_button_disable_wakeup().
701 */
702 error = devm_request_any_context_irq(dev, bdata->wakeirq, isr,
703 irqflags, wakedesc, bdata);
704 if (error < 0) {
705 dev_err(dev, "Unable to claim wakeirq %d; error %d\n",
706 bdata->irq, error);
707 return error;
708 }
709
710 /*
711 * Disable wakeirq until suspend. IRQF_NO_AUTOEN won't work if
712 * IRQF_SHARED was set based on !button->can_disable.
713 */
714 disable_irq(bdata->wakeirq);
715
716 return 0;
717}
718
719static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
720{
721 struct input_dev *input = ddata->input;
722 int i;
723
724 for (i = 0; i < ddata->pdata->nbuttons; i++) {
725 struct gpio_button_data *bdata = &ddata->data[i];
726 if (bdata->gpiod)
727 gpio_keys_gpio_report_event(bdata);
728 }
729 input_sync(input);
730}
731
732static int gpio_keys_open(struct input_dev *input)
733{
734 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
735 const struct gpio_keys_platform_data *pdata = ddata->pdata;
736 int error;
737
738 if (pdata->enable) {
739 error = pdata->enable(input->dev.parent);
740 if (error)
741 return error;
742 }
743
744 /* Report current state of buttons that are connected to GPIOs */
745 gpio_keys_report_state(ddata);
746
747 return 0;
748}
749
750static void gpio_keys_close(struct input_dev *input)
751{
752 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
753 const struct gpio_keys_platform_data *pdata = ddata->pdata;
754
755 if (pdata->disable)
756 pdata->disable(input->dev.parent);
757}
758
759/*
760 * Handlers for alternative sources of platform_data
761 */
762
763/*
764 * Translate properties into platform_data
765 */
766static struct gpio_keys_platform_data *
767gpio_keys_get_devtree_pdata(struct device *dev)
768{
769 struct gpio_keys_platform_data *pdata;
770 struct gpio_keys_button *button;
771 struct fwnode_handle *child;
772 int nbuttons, irq;
773
774 nbuttons = device_get_child_node_count(dev);
775 if (nbuttons == 0)
776 return ERR_PTR(-ENODEV);
777
778 pdata = devm_kzalloc(dev,
779 sizeof(*pdata) + nbuttons * sizeof(*button),
780 GFP_KERNEL);
781 if (!pdata)
782 return ERR_PTR(-ENOMEM);
783
784 button = (struct gpio_keys_button *)(pdata + 1);
785
786 pdata->buttons = button;
787 pdata->nbuttons = nbuttons;
788
789 pdata->rep = device_property_read_bool(dev, "autorepeat");
790
791 device_property_read_string(dev, "label", &pdata->name);
792
793 device_for_each_child_node(dev, child) {
794 if (is_of_node(child)) {
795 irq = of_irq_get_byname(to_of_node(child), "irq");
796 if (irq > 0)
797 button->irq = irq;
798
799 irq = of_irq_get_byname(to_of_node(child), "wakeup");
800 if (irq > 0)
801 button->wakeirq = irq;
802
803 if (!button->irq && !button->wakeirq)
804 button->irq =
805 irq_of_parse_and_map(to_of_node(child), 0);
806 }
807
808 if (fwnode_property_read_u32(child, "linux,code",
809 &button->code)) {
810 dev_err(dev, "Button without keycode\n");
811 fwnode_handle_put(child);
812 return ERR_PTR(-EINVAL);
813 }
814
815 fwnode_property_read_string(child, "label", &button->desc);
816
817 if (fwnode_property_read_u32(child, "linux,input-type",
818 &button->type))
819 button->type = EV_KEY;
820
821 fwnode_property_read_u32(child, "linux,input-value",
822 (u32 *)&button->value);
823
824 button->wakeup =
825 fwnode_property_read_bool(child, "wakeup-source") ||
826 /* legacy name */
827 fwnode_property_read_bool(child, "gpio-key,wakeup");
828
829 fwnode_property_read_u32(child, "wakeup-event-action",
830 &button->wakeup_event_action);
831
832 button->can_disable =
833 fwnode_property_read_bool(child, "linux,can-disable");
834
835 if (fwnode_property_read_u32(child, "debounce-interval",
836 &button->debounce_interval))
837 button->debounce_interval = 5;
838
839 button++;
840 }
841
842 return pdata;
843}
844
845static const struct of_device_id gpio_keys_of_match[] = {
846 { .compatible = "gpio-keys", },
847 { },
848};
849MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
850
851static int gpio_keys_probe(struct platform_device *pdev)
852{
853 struct device *dev = &pdev->dev;
854 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
855 struct fwnode_handle *child = NULL;
856 struct gpio_keys_drvdata *ddata;
857 struct input_dev *input;
858 int i, error;
859 int wakeup = 0;
860
861 if (!pdata) {
862 pdata = gpio_keys_get_devtree_pdata(dev);
863 if (IS_ERR(pdata))
864 return PTR_ERR(pdata);
865 }
866
867 ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
868 GFP_KERNEL);
869 if (!ddata) {
870 dev_err(dev, "failed to allocate state\n");
871 return -ENOMEM;
872 }
873
874 ddata->keymap = devm_kcalloc(dev,
875 pdata->nbuttons, sizeof(ddata->keymap[0]),
876 GFP_KERNEL);
877 if (!ddata->keymap)
878 return -ENOMEM;
879
880 input = devm_input_allocate_device(dev);
881 if (!input) {
882 dev_err(dev, "failed to allocate input device\n");
883 return -ENOMEM;
884 }
885
886 ddata->pdata = pdata;
887 ddata->input = input;
888 mutex_init(&ddata->disable_lock);
889
890 platform_set_drvdata(pdev, ddata);
891 input_set_drvdata(input, ddata);
892
893 input->name = pdata->name ? : pdev->name;
894 input->phys = "gpio-keys/input0";
895 input->dev.parent = dev;
896 input->open = gpio_keys_open;
897 input->close = gpio_keys_close;
898
899 input->id.bustype = BUS_HOST;
900 input->id.vendor = 0x0001;
901 input->id.product = 0x0001;
902 input->id.version = 0x0100;
903
904 input->keycode = ddata->keymap;
905 input->keycodesize = sizeof(ddata->keymap[0]);
906 input->keycodemax = pdata->nbuttons;
907
908 /* Enable auto repeat feature of Linux input subsystem */
909 if (pdata->rep)
910 __set_bit(EV_REP, input->evbit);
911
912 for (i = 0; i < pdata->nbuttons; i++) {
913 const struct gpio_keys_button *button = &pdata->buttons[i];
914
915 if (!dev_get_platdata(dev)) {
916 child = device_get_next_child_node(dev, child);
917 if (!child) {
918 dev_err(dev,
919 "missing child device node for entry %d\n",
920 i);
921 return -EINVAL;
922 }
923 }
924
925 error = gpio_keys_setup_key(pdev, input, ddata,
926 button, i, child);
927 if (error) {
928 fwnode_handle_put(child);
929 return error;
930 }
931
932 if (button->wakeup)
933 wakeup = 1;
934 }
935
936 fwnode_handle_put(child);
937
938 error = input_register_device(input);
939 if (error) {
940 dev_err(dev, "Unable to register input device, error: %d\n",
941 error);
942 return error;
943 }
944
945 device_init_wakeup(dev, wakeup);
946
947 return 0;
948}
949
950static int __maybe_unused
951gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
952{
953 int error;
954
955 error = enable_irq_wake(bdata->irq);
956 if (error) {
957 dev_err(bdata->input->dev.parent,
958 "failed to configure IRQ %d as wakeup source: %d\n",
959 bdata->irq, error);
960 return error;
961 }
962
963 if (bdata->wakeup_trigger_type) {
964 error = irq_set_irq_type(bdata->irq,
965 bdata->wakeup_trigger_type);
966 if (error) {
967 dev_err(bdata->input->dev.parent,
968 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
969 bdata->wakeup_trigger_type, bdata->irq, error);
970 disable_irq_wake(bdata->irq);
971 return error;
972 }
973 }
974
975 if (bdata->wakeirq) {
976 enable_irq(bdata->wakeirq);
977 disable_irq(bdata->irq);
978 }
979
980 return 0;
981}
982
983static void __maybe_unused
984gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
985{
986 int error;
987
988 if (bdata->wakeirq) {
989 enable_irq(bdata->irq);
990 disable_irq(bdata->wakeirq);
991 }
992
993 /*
994 * The trigger type is always both edges for gpio-based keys and we do
995 * not support changing wakeup trigger for interrupt-based keys.
996 */
997 if (bdata->wakeup_trigger_type) {
998 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
999 if (error)
1000 dev_warn(bdata->input->dev.parent,
1001 "failed to restore interrupt trigger for IRQ %d: %d\n",
1002 bdata->irq, error);
1003 }
1004
1005 error = disable_irq_wake(bdata->irq);
1006 if (error)
1007 dev_warn(bdata->input->dev.parent,
1008 "failed to disable IRQ %d as wake source: %d\n",
1009 bdata->irq, error);
1010}
1011
1012static int __maybe_unused
1013gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
1014{
1015 struct gpio_button_data *bdata;
1016 int error;
1017 int i;
1018
1019 for (i = 0; i < ddata->pdata->nbuttons; i++) {
1020 bdata = &ddata->data[i];
1021 if (bdata->button->wakeup) {
1022 error = gpio_keys_button_enable_wakeup(bdata);
1023 if (error)
1024 goto err_out;
1025 }
1026 bdata->suspended = true;
1027 }
1028
1029 return 0;
1030
1031err_out:
1032 while (i--) {
1033 bdata = &ddata->data[i];
1034 if (bdata->button->wakeup)
1035 gpio_keys_button_disable_wakeup(bdata);
1036 bdata->suspended = false;
1037 }
1038
1039 return error;
1040}
1041
1042static void __maybe_unused
1043gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
1044{
1045 struct gpio_button_data *bdata;
1046 int i;
1047
1048 for (i = 0; i < ddata->pdata->nbuttons; i++) {
1049 bdata = &ddata->data[i];
1050 bdata->suspended = false;
1051 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
1052 gpio_keys_button_disable_wakeup(bdata);
1053 }
1054}
1055
1056static int gpio_keys_suspend(struct device *dev)
1057{
1058 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
1059 struct input_dev *input = ddata->input;
1060 int error;
1061
1062 if (device_may_wakeup(dev)) {
1063 error = gpio_keys_enable_wakeup(ddata);
1064 if (error)
1065 return error;
1066 } else {
1067 mutex_lock(&input->mutex);
1068 if (input_device_enabled(input))
1069 gpio_keys_close(input);
1070 mutex_unlock(&input->mutex);
1071 }
1072
1073 return 0;
1074}
1075
1076static int gpio_keys_resume(struct device *dev)
1077{
1078 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
1079 struct input_dev *input = ddata->input;
1080 int error = 0;
1081
1082 if (device_may_wakeup(dev)) {
1083 gpio_keys_disable_wakeup(ddata);
1084 } else {
1085 mutex_lock(&input->mutex);
1086 if (input_device_enabled(input))
1087 error = gpio_keys_open(input);
1088 mutex_unlock(&input->mutex);
1089 }
1090
1091 if (error)
1092 return error;
1093
1094 gpio_keys_report_state(ddata);
1095 return 0;
1096}
1097
1098static DEFINE_SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1099
1100static void gpio_keys_shutdown(struct platform_device *pdev)
1101{
1102 int ret;
1103
1104 ret = gpio_keys_suspend(&pdev->dev);
1105 if (ret)
1106 dev_err(&pdev->dev, "failed to shutdown\n");
1107}
1108
1109static struct platform_driver gpio_keys_device_driver = {
1110 .probe = gpio_keys_probe,
1111 .shutdown = gpio_keys_shutdown,
1112 .driver = {
1113 .name = "gpio-keys",
1114 .pm = pm_sleep_ptr(&gpio_keys_pm_ops),
1115 .of_match_table = gpio_keys_of_match,
1116 .dev_groups = gpio_keys_groups,
1117 }
1118};
1119
1120static int __init gpio_keys_init(void)
1121{
1122 return platform_driver_register(&gpio_keys_device_driver);
1123}
1124
1125static void __exit gpio_keys_exit(void)
1126{
1127 platform_driver_unregister(&gpio_keys_device_driver);
1128}
1129
1130late_initcall(gpio_keys_init);
1131module_exit(gpio_keys_exit);
1132
1133MODULE_LICENSE("GPL");
1134MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1135MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1136MODULE_ALIAS("platform:gpio-keys");
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/init.h>
12#include <linux/fs.h>
13#include <linux/interrupt.h>
14#include <linux/irq.h>
15#include <linux/sched.h>
16#include <linux/pm.h>
17#include <linux/slab.h>
18#include <linux/sysctl.h>
19#include <linux/proc_fs.h>
20#include <linux/delay.h>
21#include <linux/platform_device.h>
22#include <linux/input.h>
23#include <linux/gpio_keys.h>
24#include <linux/workqueue.h>
25#include <linux/gpio.h>
26#include <linux/gpio/consumer.h>
27#include <linux/of.h>
28#include <linux/of_irq.h>
29#include <linux/spinlock.h>
30#include <dt-bindings/input/gpio-keys.h>
31
32struct gpio_button_data {
33 const struct gpio_keys_button *button;
34 struct input_dev *input;
35 struct gpio_desc *gpiod;
36
37 unsigned short *code;
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 unsigned int wakeup_trigger_type;
47 spinlock_t lock;
48 bool disabled;
49 bool key_pressed;
50 bool suspended;
51};
52
53struct gpio_keys_drvdata {
54 const struct gpio_keys_platform_data *pdata;
55 struct input_dev *input;
56 struct mutex disable_lock;
57 unsigned short *keymap;
58 struct gpio_button_data data[];
59};
60
61/*
62 * SYSFS interface for enabling/disabling keys and switches:
63 *
64 * There are 4 attributes under /sys/devices/platform/gpio-keys/
65 * keys [ro] - bitmap of keys (EV_KEY) which can be
66 * disabled
67 * switches [ro] - bitmap of switches (EV_SW) which can be
68 * disabled
69 * disabled_keys [rw] - bitmap of keys currently disabled
70 * disabled_switches [rw] - bitmap of switches currently disabled
71 *
72 * Userland can change these values and hence disable event generation
73 * for each key (or switch). Disabling a key means its interrupt line
74 * is disabled.
75 *
76 * For example, if we have following switches set up as gpio-keys:
77 * SW_DOCK = 5
78 * SW_CAMERA_LENS_COVER = 9
79 * SW_KEYPAD_SLIDE = 10
80 * SW_FRONT_PROXIMITY = 11
81 * This is read from switches:
82 * 11-9,5
83 * Next we want to disable proximity (11) and dock (5), we write:
84 * 11,5
85 * to file disabled_switches. Now proximity and dock IRQs are disabled.
86 * This can be verified by reading the file disabled_switches:
87 * 11,5
88 * If we now want to enable proximity (11) switch we write:
89 * 5
90 * to disabled_switches.
91 *
92 * We can disable only those keys which don't allow sharing the irq.
93 */
94
95/**
96 * get_n_events_by_type() - returns maximum number of events per @type
97 * @type: type of button (%EV_KEY, %EV_SW)
98 *
99 * Return value of this function can be used to allocate bitmap
100 * large enough to hold all bits for given type.
101 */
102static int get_n_events_by_type(int type)
103{
104 BUG_ON(type != EV_SW && type != EV_KEY);
105
106 return (type == EV_KEY) ? KEY_CNT : SW_CNT;
107}
108
109/**
110 * get_bm_events_by_type() - returns bitmap of supported events per @type
111 * @input: input device from which bitmap is retrieved
112 * @type: type of button (%EV_KEY, %EV_SW)
113 *
114 * Return value of this function can be used to allocate bitmap
115 * large enough to hold all bits for given type.
116 */
117static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
118 int type)
119{
120 BUG_ON(type != EV_SW && type != EV_KEY);
121
122 return (type == EV_KEY) ? dev->keybit : dev->swbit;
123}
124
125/**
126 * gpio_keys_disable_button() - disables given GPIO button
127 * @bdata: button data for button to be disabled
128 *
129 * Disables button pointed by @bdata. This is done by masking
130 * IRQ line. After this function is called, button won't generate
131 * input events anymore. Note that one can only disable buttons
132 * that don't share IRQs.
133 *
134 * Make sure that @bdata->disable_lock is locked when entering
135 * this function to avoid races when concurrent threads are
136 * disabling buttons at the same time.
137 */
138static void gpio_keys_disable_button(struct gpio_button_data *bdata)
139{
140 if (!bdata->disabled) {
141 /*
142 * Disable IRQ and associated timer/work structure.
143 */
144 disable_irq(bdata->irq);
145
146 if (bdata->gpiod)
147 cancel_delayed_work_sync(&bdata->work);
148 else
149 del_timer_sync(&bdata->release_timer);
150
151 bdata->disabled = true;
152 }
153}
154
155/**
156 * gpio_keys_enable_button() - enables given GPIO button
157 * @bdata: button data for button to be disabled
158 *
159 * Enables given button pointed by @bdata.
160 *
161 * Make sure that @bdata->disable_lock is locked when entering
162 * this function to avoid races with concurrent threads trying
163 * to enable the same button at the same time.
164 */
165static void gpio_keys_enable_button(struct gpio_button_data *bdata)
166{
167 if (bdata->disabled) {
168 enable_irq(bdata->irq);
169 bdata->disabled = false;
170 }
171}
172
173/**
174 * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
175 * @ddata: pointer to drvdata
176 * @buf: buffer where stringified bitmap is written
177 * @type: button type (%EV_KEY, %EV_SW)
178 * @only_disabled: does caller want only those buttons that are
179 * currently disabled or all buttons that can be
180 * disabled
181 *
182 * This function writes buttons that can be disabled to @buf. If
183 * @only_disabled is true, then @buf contains only those buttons
184 * that are currently disabled. Returns 0 on success or negative
185 * errno on failure.
186 */
187static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
188 char *buf, unsigned int type,
189 bool only_disabled)
190{
191 int n_events = get_n_events_by_type(type);
192 unsigned long *bits;
193 ssize_t ret;
194 int i;
195
196 bits = bitmap_zalloc(n_events, GFP_KERNEL);
197 if (!bits)
198 return -ENOMEM;
199
200 for (i = 0; i < ddata->pdata->nbuttons; i++) {
201 struct gpio_button_data *bdata = &ddata->data[i];
202
203 if (bdata->button->type != type)
204 continue;
205
206 if (only_disabled && !bdata->disabled)
207 continue;
208
209 __set_bit(*bdata->code, bits);
210 }
211
212 ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
213 buf[ret++] = '\n';
214 buf[ret] = '\0';
215
216 bitmap_free(bits);
217
218 return ret;
219}
220
221/**
222 * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
223 * @ddata: pointer to drvdata
224 * @buf: buffer from userspace that contains stringified bitmap
225 * @type: button type (%EV_KEY, %EV_SW)
226 *
227 * This function parses stringified bitmap from @buf and disables/enables
228 * GPIO buttons accordingly. Returns 0 on success and negative error
229 * on failure.
230 */
231static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
232 const char *buf, unsigned int type)
233{
234 int n_events = get_n_events_by_type(type);
235 const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
236 unsigned long *bits;
237 ssize_t error;
238 int i;
239
240 bits = bitmap_zalloc(n_events, GFP_KERNEL);
241 if (!bits)
242 return -ENOMEM;
243
244 error = bitmap_parselist(buf, bits, n_events);
245 if (error)
246 goto out;
247
248 /* First validate */
249 if (!bitmap_subset(bits, bitmap, n_events)) {
250 error = -EINVAL;
251 goto out;
252 }
253
254 for (i = 0; i < ddata->pdata->nbuttons; i++) {
255 struct gpio_button_data *bdata = &ddata->data[i];
256
257 if (bdata->button->type != type)
258 continue;
259
260 if (test_bit(*bdata->code, bits) &&
261 !bdata->button->can_disable) {
262 error = -EINVAL;
263 goto out;
264 }
265 }
266
267 mutex_lock(&ddata->disable_lock);
268
269 for (i = 0; i < ddata->pdata->nbuttons; i++) {
270 struct gpio_button_data *bdata = &ddata->data[i];
271
272 if (bdata->button->type != type)
273 continue;
274
275 if (test_bit(*bdata->code, bits))
276 gpio_keys_disable_button(bdata);
277 else
278 gpio_keys_enable_button(bdata);
279 }
280
281 mutex_unlock(&ddata->disable_lock);
282
283out:
284 bitmap_free(bits);
285 return error;
286}
287
288#define ATTR_SHOW_FN(name, type, only_disabled) \
289static ssize_t gpio_keys_show_##name(struct device *dev, \
290 struct device_attribute *attr, \
291 char *buf) \
292{ \
293 struct platform_device *pdev = to_platform_device(dev); \
294 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
295 \
296 return gpio_keys_attr_show_helper(ddata, buf, \
297 type, only_disabled); \
298}
299
300ATTR_SHOW_FN(keys, EV_KEY, false);
301ATTR_SHOW_FN(switches, EV_SW, false);
302ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
303ATTR_SHOW_FN(disabled_switches, EV_SW, true);
304
305/*
306 * ATTRIBUTES:
307 *
308 * /sys/devices/platform/gpio-keys/keys [ro]
309 * /sys/devices/platform/gpio-keys/switches [ro]
310 */
311static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
312static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
313
314#define ATTR_STORE_FN(name, type) \
315static ssize_t gpio_keys_store_##name(struct device *dev, \
316 struct device_attribute *attr, \
317 const char *buf, \
318 size_t count) \
319{ \
320 struct platform_device *pdev = to_platform_device(dev); \
321 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
322 ssize_t error; \
323 \
324 error = gpio_keys_attr_store_helper(ddata, buf, type); \
325 if (error) \
326 return error; \
327 \
328 return count; \
329}
330
331ATTR_STORE_FN(disabled_keys, EV_KEY);
332ATTR_STORE_FN(disabled_switches, EV_SW);
333
334/*
335 * ATTRIBUTES:
336 *
337 * /sys/devices/platform/gpio-keys/disabled_keys [rw]
338 * /sys/devices/platform/gpio-keys/disables_switches [rw]
339 */
340static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
341 gpio_keys_show_disabled_keys,
342 gpio_keys_store_disabled_keys);
343static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
344 gpio_keys_show_disabled_switches,
345 gpio_keys_store_disabled_switches);
346
347static struct attribute *gpio_keys_attrs[] = {
348 &dev_attr_keys.attr,
349 &dev_attr_switches.attr,
350 &dev_attr_disabled_keys.attr,
351 &dev_attr_disabled_switches.attr,
352 NULL,
353};
354ATTRIBUTE_GROUPS(gpio_keys);
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, *bdata->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 const struct gpio_keys_button *button = bdata->button;
398
399 pm_stay_awake(bdata->input->dev.parent);
400 if (bdata->suspended &&
401 (button->type == 0 || button->type == EV_KEY)) {
402 /*
403 * Simulate wakeup key press in case the key has
404 * already released by the time we got interrupt
405 * handler to run.
406 */
407 input_report_key(bdata->input, button->code, 1);
408 }
409 }
410
411 mod_delayed_work(system_wq,
412 &bdata->work,
413 msecs_to_jiffies(bdata->software_debounce));
414
415 return IRQ_HANDLED;
416}
417
418static void gpio_keys_irq_timer(struct timer_list *t)
419{
420 struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
421 struct input_dev *input = bdata->input;
422 unsigned long flags;
423
424 spin_lock_irqsave(&bdata->lock, flags);
425 if (bdata->key_pressed) {
426 input_event(input, EV_KEY, *bdata->code, 0);
427 input_sync(input);
428 bdata->key_pressed = false;
429 }
430 spin_unlock_irqrestore(&bdata->lock, flags);
431}
432
433static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
434{
435 struct gpio_button_data *bdata = dev_id;
436 struct input_dev *input = bdata->input;
437 unsigned long flags;
438
439 BUG_ON(irq != bdata->irq);
440
441 spin_lock_irqsave(&bdata->lock, flags);
442
443 if (!bdata->key_pressed) {
444 if (bdata->button->wakeup)
445 pm_wakeup_event(bdata->input->dev.parent, 0);
446
447 input_event(input, EV_KEY, *bdata->code, 1);
448 input_sync(input);
449
450 if (!bdata->release_delay) {
451 input_event(input, EV_KEY, *bdata->code, 0);
452 input_sync(input);
453 goto out;
454 }
455
456 bdata->key_pressed = true;
457 }
458
459 if (bdata->release_delay)
460 mod_timer(&bdata->release_timer,
461 jiffies + msecs_to_jiffies(bdata->release_delay));
462out:
463 spin_unlock_irqrestore(&bdata->lock, flags);
464 return IRQ_HANDLED;
465}
466
467static void gpio_keys_quiesce_key(void *data)
468{
469 struct gpio_button_data *bdata = data;
470
471 if (bdata->gpiod)
472 cancel_delayed_work_sync(&bdata->work);
473 else
474 del_timer_sync(&bdata->release_timer);
475}
476
477static int gpio_keys_setup_key(struct platform_device *pdev,
478 struct input_dev *input,
479 struct gpio_keys_drvdata *ddata,
480 const struct gpio_keys_button *button,
481 int idx,
482 struct fwnode_handle *child)
483{
484 const char *desc = button->desc ? button->desc : "gpio_keys";
485 struct device *dev = &pdev->dev;
486 struct gpio_button_data *bdata = &ddata->data[idx];
487 irq_handler_t isr;
488 unsigned long irqflags;
489 int irq;
490 int error;
491
492 bdata->input = input;
493 bdata->button = button;
494 spin_lock_init(&bdata->lock);
495
496 if (child) {
497 bdata->gpiod = devm_fwnode_gpiod_get(dev, child,
498 NULL, GPIOD_IN, desc);
499 if (IS_ERR(bdata->gpiod)) {
500 error = PTR_ERR(bdata->gpiod);
501 if (error == -ENOENT) {
502 /*
503 * GPIO is optional, we may be dealing with
504 * purely interrupt-driven setup.
505 */
506 bdata->gpiod = NULL;
507 } else {
508 if (error != -EPROBE_DEFER)
509 dev_err(dev, "failed to get gpio: %d\n",
510 error);
511 return error;
512 }
513 }
514 } else if (gpio_is_valid(button->gpio)) {
515 /*
516 * Legacy GPIO number, so request the GPIO here and
517 * convert it to descriptor.
518 */
519 unsigned flags = GPIOF_IN;
520
521 if (button->active_low)
522 flags |= GPIOF_ACTIVE_LOW;
523
524 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
525 if (error < 0) {
526 dev_err(dev, "Failed to request GPIO %d, error %d\n",
527 button->gpio, error);
528 return error;
529 }
530
531 bdata->gpiod = gpio_to_desc(button->gpio);
532 if (!bdata->gpiod)
533 return -EINVAL;
534 }
535
536 if (bdata->gpiod) {
537 bool active_low = gpiod_is_active_low(bdata->gpiod);
538
539 if (button->debounce_interval) {
540 error = gpiod_set_debounce(bdata->gpiod,
541 button->debounce_interval * 1000);
542 /* use timer if gpiolib doesn't provide debounce */
543 if (error < 0)
544 bdata->software_debounce =
545 button->debounce_interval;
546 }
547
548 if (button->irq) {
549 bdata->irq = button->irq;
550 } else {
551 irq = gpiod_to_irq(bdata->gpiod);
552 if (irq < 0) {
553 error = irq;
554 dev_err(dev,
555 "Unable to get irq number for GPIO %d, error %d\n",
556 button->gpio, error);
557 return error;
558 }
559 bdata->irq = irq;
560 }
561
562 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
563
564 isr = gpio_keys_gpio_isr;
565 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
566
567 switch (button->wakeup_event_action) {
568 case EV_ACT_ASSERTED:
569 bdata->wakeup_trigger_type = active_low ?
570 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
571 break;
572 case EV_ACT_DEASSERTED:
573 bdata->wakeup_trigger_type = active_low ?
574 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
575 break;
576 case EV_ACT_ANY:
577 default:
578 /*
579 * For other cases, we are OK letting suspend/resume
580 * not reconfigure the trigger type.
581 */
582 break;
583 }
584 } else {
585 if (!button->irq) {
586 dev_err(dev, "Found button without gpio or irq\n");
587 return -EINVAL;
588 }
589
590 bdata->irq = button->irq;
591
592 if (button->type && button->type != EV_KEY) {
593 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
594 return -EINVAL;
595 }
596
597 bdata->release_delay = button->debounce_interval;
598 timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
599
600 isr = gpio_keys_irq_isr;
601 irqflags = 0;
602
603 /*
604 * For IRQ buttons, there is no interrupt for release.
605 * So we don't need to reconfigure the trigger type for wakeup.
606 */
607 }
608
609 bdata->code = &ddata->keymap[idx];
610 *bdata->code = button->code;
611 input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
612
613 /*
614 * Install custom action to cancel release timer and
615 * workqueue item.
616 */
617 error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
618 if (error) {
619 dev_err(dev, "failed to register quiesce action, error: %d\n",
620 error);
621 return error;
622 }
623
624 /*
625 * If platform has specified that the button can be disabled,
626 * we don't want it to share the interrupt line.
627 */
628 if (!button->can_disable)
629 irqflags |= IRQF_SHARED;
630
631 error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
632 desc, bdata);
633 if (error < 0) {
634 dev_err(dev, "Unable to claim irq %d; error %d\n",
635 bdata->irq, error);
636 return error;
637 }
638
639 return 0;
640}
641
642static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
643{
644 struct input_dev *input = ddata->input;
645 int i;
646
647 for (i = 0; i < ddata->pdata->nbuttons; i++) {
648 struct gpio_button_data *bdata = &ddata->data[i];
649 if (bdata->gpiod)
650 gpio_keys_gpio_report_event(bdata);
651 }
652 input_sync(input);
653}
654
655static int gpio_keys_open(struct input_dev *input)
656{
657 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
658 const struct gpio_keys_platform_data *pdata = ddata->pdata;
659 int error;
660
661 if (pdata->enable) {
662 error = pdata->enable(input->dev.parent);
663 if (error)
664 return error;
665 }
666
667 /* Report current state of buttons that are connected to GPIOs */
668 gpio_keys_report_state(ddata);
669
670 return 0;
671}
672
673static void gpio_keys_close(struct input_dev *input)
674{
675 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
676 const struct gpio_keys_platform_data *pdata = ddata->pdata;
677
678 if (pdata->disable)
679 pdata->disable(input->dev.parent);
680}
681
682/*
683 * Handlers for alternative sources of platform_data
684 */
685
686/*
687 * Translate properties into platform_data
688 */
689static struct gpio_keys_platform_data *
690gpio_keys_get_devtree_pdata(struct device *dev)
691{
692 struct gpio_keys_platform_data *pdata;
693 struct gpio_keys_button *button;
694 struct fwnode_handle *child;
695 int nbuttons;
696
697 nbuttons = device_get_child_node_count(dev);
698 if (nbuttons == 0)
699 return ERR_PTR(-ENODEV);
700
701 pdata = devm_kzalloc(dev,
702 sizeof(*pdata) + nbuttons * sizeof(*button),
703 GFP_KERNEL);
704 if (!pdata)
705 return ERR_PTR(-ENOMEM);
706
707 button = (struct gpio_keys_button *)(pdata + 1);
708
709 pdata->buttons = button;
710 pdata->nbuttons = nbuttons;
711
712 pdata->rep = device_property_read_bool(dev, "autorepeat");
713
714 device_property_read_string(dev, "label", &pdata->name);
715
716 device_for_each_child_node(dev, child) {
717 if (is_of_node(child))
718 button->irq =
719 irq_of_parse_and_map(to_of_node(child), 0);
720
721 if (fwnode_property_read_u32(child, "linux,code",
722 &button->code)) {
723 dev_err(dev, "Button without keycode\n");
724 fwnode_handle_put(child);
725 return ERR_PTR(-EINVAL);
726 }
727
728 fwnode_property_read_string(child, "label", &button->desc);
729
730 if (fwnode_property_read_u32(child, "linux,input-type",
731 &button->type))
732 button->type = EV_KEY;
733
734 button->wakeup =
735 fwnode_property_read_bool(child, "wakeup-source") ||
736 /* legacy name */
737 fwnode_property_read_bool(child, "gpio-key,wakeup");
738
739 fwnode_property_read_u32(child, "wakeup-event-action",
740 &button->wakeup_event_action);
741
742 button->can_disable =
743 fwnode_property_read_bool(child, "linux,can-disable");
744
745 if (fwnode_property_read_u32(child, "debounce-interval",
746 &button->debounce_interval))
747 button->debounce_interval = 5;
748
749 button++;
750 }
751
752 return pdata;
753}
754
755static const struct of_device_id gpio_keys_of_match[] = {
756 { .compatible = "gpio-keys", },
757 { },
758};
759MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
760
761static int gpio_keys_probe(struct platform_device *pdev)
762{
763 struct device *dev = &pdev->dev;
764 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
765 struct fwnode_handle *child = NULL;
766 struct gpio_keys_drvdata *ddata;
767 struct input_dev *input;
768 int i, error;
769 int wakeup = 0;
770
771 if (!pdata) {
772 pdata = gpio_keys_get_devtree_pdata(dev);
773 if (IS_ERR(pdata))
774 return PTR_ERR(pdata);
775 }
776
777 ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
778 GFP_KERNEL);
779 if (!ddata) {
780 dev_err(dev, "failed to allocate state\n");
781 return -ENOMEM;
782 }
783
784 ddata->keymap = devm_kcalloc(dev,
785 pdata->nbuttons, sizeof(ddata->keymap[0]),
786 GFP_KERNEL);
787 if (!ddata->keymap)
788 return -ENOMEM;
789
790 input = devm_input_allocate_device(dev);
791 if (!input) {
792 dev_err(dev, "failed to allocate input device\n");
793 return -ENOMEM;
794 }
795
796 ddata->pdata = pdata;
797 ddata->input = input;
798 mutex_init(&ddata->disable_lock);
799
800 platform_set_drvdata(pdev, ddata);
801 input_set_drvdata(input, ddata);
802
803 input->name = pdata->name ? : pdev->name;
804 input->phys = "gpio-keys/input0";
805 input->dev.parent = dev;
806 input->open = gpio_keys_open;
807 input->close = gpio_keys_close;
808
809 input->id.bustype = BUS_HOST;
810 input->id.vendor = 0x0001;
811 input->id.product = 0x0001;
812 input->id.version = 0x0100;
813
814 input->keycode = ddata->keymap;
815 input->keycodesize = sizeof(ddata->keymap[0]);
816 input->keycodemax = pdata->nbuttons;
817
818 /* Enable auto repeat feature of Linux input subsystem */
819 if (pdata->rep)
820 __set_bit(EV_REP, input->evbit);
821
822 for (i = 0; i < pdata->nbuttons; i++) {
823 const struct gpio_keys_button *button = &pdata->buttons[i];
824
825 if (!dev_get_platdata(dev)) {
826 child = device_get_next_child_node(dev, child);
827 if (!child) {
828 dev_err(dev,
829 "missing child device node for entry %d\n",
830 i);
831 return -EINVAL;
832 }
833 }
834
835 error = gpio_keys_setup_key(pdev, input, ddata,
836 button, i, child);
837 if (error) {
838 fwnode_handle_put(child);
839 return error;
840 }
841
842 if (button->wakeup)
843 wakeup = 1;
844 }
845
846 fwnode_handle_put(child);
847
848 error = input_register_device(input);
849 if (error) {
850 dev_err(dev, "Unable to register input device, error: %d\n",
851 error);
852 return error;
853 }
854
855 device_init_wakeup(dev, wakeup);
856
857 return 0;
858}
859
860static int __maybe_unused
861gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
862{
863 int error;
864
865 error = enable_irq_wake(bdata->irq);
866 if (error) {
867 dev_err(bdata->input->dev.parent,
868 "failed to configure IRQ %d as wakeup source: %d\n",
869 bdata->irq, error);
870 return error;
871 }
872
873 if (bdata->wakeup_trigger_type) {
874 error = irq_set_irq_type(bdata->irq,
875 bdata->wakeup_trigger_type);
876 if (error) {
877 dev_err(bdata->input->dev.parent,
878 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
879 bdata->wakeup_trigger_type, bdata->irq, error);
880 disable_irq_wake(bdata->irq);
881 return error;
882 }
883 }
884
885 return 0;
886}
887
888static void __maybe_unused
889gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
890{
891 int error;
892
893 /*
894 * The trigger type is always both edges for gpio-based keys and we do
895 * not support changing wakeup trigger for interrupt-based keys.
896 */
897 if (bdata->wakeup_trigger_type) {
898 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
899 if (error)
900 dev_warn(bdata->input->dev.parent,
901 "failed to restore interrupt trigger for IRQ %d: %d\n",
902 bdata->irq, error);
903 }
904
905 error = disable_irq_wake(bdata->irq);
906 if (error)
907 dev_warn(bdata->input->dev.parent,
908 "failed to disable IRQ %d as wake source: %d\n",
909 bdata->irq, error);
910}
911
912static int __maybe_unused
913gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
914{
915 struct gpio_button_data *bdata;
916 int error;
917 int i;
918
919 for (i = 0; i < ddata->pdata->nbuttons; i++) {
920 bdata = &ddata->data[i];
921 if (bdata->button->wakeup) {
922 error = gpio_keys_button_enable_wakeup(bdata);
923 if (error)
924 goto err_out;
925 }
926 bdata->suspended = true;
927 }
928
929 return 0;
930
931err_out:
932 while (i--) {
933 bdata = &ddata->data[i];
934 if (bdata->button->wakeup)
935 gpio_keys_button_disable_wakeup(bdata);
936 bdata->suspended = false;
937 }
938
939 return error;
940}
941
942static void __maybe_unused
943gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
944{
945 struct gpio_button_data *bdata;
946 int i;
947
948 for (i = 0; i < ddata->pdata->nbuttons; i++) {
949 bdata = &ddata->data[i];
950 bdata->suspended = false;
951 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
952 gpio_keys_button_disable_wakeup(bdata);
953 }
954}
955
956static int __maybe_unused gpio_keys_suspend(struct device *dev)
957{
958 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
959 struct input_dev *input = ddata->input;
960 int error;
961
962 if (device_may_wakeup(dev)) {
963 error = gpio_keys_enable_wakeup(ddata);
964 if (error)
965 return error;
966 } else {
967 mutex_lock(&input->mutex);
968 if (input->users)
969 gpio_keys_close(input);
970 mutex_unlock(&input->mutex);
971 }
972
973 return 0;
974}
975
976static int __maybe_unused gpio_keys_resume(struct device *dev)
977{
978 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
979 struct input_dev *input = ddata->input;
980 int error = 0;
981
982 if (device_may_wakeup(dev)) {
983 gpio_keys_disable_wakeup(ddata);
984 } else {
985 mutex_lock(&input->mutex);
986 if (input->users)
987 error = gpio_keys_open(input);
988 mutex_unlock(&input->mutex);
989 }
990
991 if (error)
992 return error;
993
994 gpio_keys_report_state(ddata);
995 return 0;
996}
997
998static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
999
1000static void gpio_keys_shutdown(struct platform_device *pdev)
1001{
1002 int ret;
1003
1004 ret = gpio_keys_suspend(&pdev->dev);
1005 if (ret)
1006 dev_err(&pdev->dev, "failed to shutdown\n");
1007}
1008
1009static struct platform_driver gpio_keys_device_driver = {
1010 .probe = gpio_keys_probe,
1011 .shutdown = gpio_keys_shutdown,
1012 .driver = {
1013 .name = "gpio-keys",
1014 .pm = &gpio_keys_pm_ops,
1015 .of_match_table = gpio_keys_of_match,
1016 .dev_groups = gpio_keys_groups,
1017 }
1018};
1019
1020static int __init gpio_keys_init(void)
1021{
1022 return platform_driver_register(&gpio_keys_device_driver);
1023}
1024
1025static void __exit gpio_keys_exit(void)
1026{
1027 platform_driver_unregister(&gpio_keys_device_driver);
1028}
1029
1030late_initcall(gpio_keys_init);
1031module_exit(gpio_keys_exit);
1032
1033MODULE_LICENSE("GPL");
1034MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1035MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1036MODULE_ALIAS("platform:gpio-keys");