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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// 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");