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