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(timer: &bdata->release_timer);
134 else if (bdata->debounce_use_hrtimer)
135 hrtimer_cancel(timer: &bdata->debounce_timer);
136 else
137 cancel_delayed_work_sync(dwork: &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(irq: bdata->irq);
160 gpio_keys_quiesce_key(data: 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(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(nbits: 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, fmt: "%*pbl", n_events, bits);
223 buf[ret++] = '\n';
224 buf[ret] = '\0';
225
226 bitmap_free(bitmap: 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(dev: ddata->input, type);
246 unsigned long *bits;
247 ssize_t error;
248 int i;
249
250 bits = bitmap_alloc(nbits: n_events, GFP_KERNEL);
251 if (!bits)
252 return -ENOMEM;
253
254 error = bitmap_parselist(buf, maskp: bits, nmaskbits: n_events);
255 if (error)
256 goto out;
257
258 /* First validate */
259 if (!bitmap_subset(src1: bits, src2: bitmap, nbits: 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(lock: &ddata->disable_lock);
292
293out:
294 bitmap_free(bitmap: 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(desc: bdata->gpiod) :
375 gpiod_get_value_cansleep(desc: 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(dev: input, type, code: button->code, value: button->value);
385 } else {
386 input_event(dev: input, type, code: *bdata->code, value: 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(dev: bdata->input);
394
395 if (bdata->button->wakeup)
396 pm_relax(dev: 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(dev: 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(dev: bdata->input, code: button->code, value: 1);
435 }
436 }
437
438 if (bdata->debounce_use_hrtimer) {
439 hrtimer_start(timer: &bdata->debounce_timer,
440 tim: ms_to_ktime(ms: bdata->software_debounce),
441 mode: HRTIMER_MODE_REL);
442 } else {
443 mod_delayed_work(wq: system_wq,
444 dwork: &bdata->work,
445 delay: msecs_to_jiffies(m: 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_report_key(dev: input, code: *bdata->code, value: 0);
460 input_sync(dev: 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(dev: bdata->input->dev.parent, msec: 0);
480
481 input_report_key(dev: input, code: *bdata->code, value: 1);
482 input_sync(dev: input);
483
484 if (!bdata->release_delay) {
485 input_report_key(dev: input, code: *bdata->code, value: 0);
486 input_sync(dev: input);
487 goto out;
488 }
489
490 bdata->key_pressed = true;
491 }
492
493 if (bdata->release_delay)
494 hrtimer_start(timer: &bdata->release_timer,
495 tim: ms_to_ktime(ms: bdata->release_delay),
496 mode: HRTIMER_MODE_REL_HARD);
497out:
498 spin_unlock_irqrestore(lock: &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, fwnode: child,
523 NULL, flags: GPIOD_IN, label: desc);
524 if (IS_ERR(ptr: bdata->gpiod)) {
525 error = PTR_ERR(ptr: bdata->gpiod);
526 if (error != -ENOENT)
527 return dev_err_probe(dev, err: error,
528 fmt: "failed to get gpio\n");
529
530 /*
531 * GPIO is optional, we may be dealing with
532 * purely interrupt-driven setup.
533 */
534 bdata->gpiod = NULL;
535 }
536 } else if (gpio_is_valid(number: button->gpio)) {
537 /*
538 * Legacy GPIO number, so request the GPIO here and
539 * convert it to descriptor.
540 */
541 unsigned flags = GPIOF_IN;
542
543 if (button->active_low)
544 flags |= GPIOF_ACTIVE_LOW;
545
546 error = devm_gpio_request_one(dev, gpio: button->gpio, flags, label: desc);
547 if (error < 0) {
548 dev_err(dev, "Failed to request GPIO %d, error %d\n",
549 button->gpio, error);
550 return error;
551 }
552
553 bdata->gpiod = gpio_to_desc(gpio: button->gpio);
554 if (!bdata->gpiod)
555 return -EINVAL;
556 }
557
558 if (bdata->gpiod) {
559 bool active_low = gpiod_is_active_low(desc: bdata->gpiod);
560
561 if (button->debounce_interval) {
562 error = gpiod_set_debounce(desc: bdata->gpiod,
563 debounce: button->debounce_interval * 1000);
564 /* use timer if gpiolib doesn't provide debounce */
565 if (error < 0)
566 bdata->software_debounce =
567 button->debounce_interval;
568
569 /*
570 * If reading the GPIO won't sleep, we can use a
571 * hrtimer instead of a standard timer for the software
572 * debounce, to reduce the latency as much as possible.
573 */
574 bdata->debounce_use_hrtimer =
575 !gpiod_cansleep(desc: bdata->gpiod);
576 }
577
578 if (button->irq) {
579 bdata->irq = button->irq;
580 } else {
581 irq = gpiod_to_irq(desc: bdata->gpiod);
582 if (irq < 0) {
583 error = irq;
584 dev_err(dev,
585 "Unable to get irq number for GPIO %d, error %d\n",
586 button->gpio, error);
587 return error;
588 }
589 bdata->irq = irq;
590 }
591
592 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
593
594 hrtimer_init(timer: &bdata->debounce_timer,
595 CLOCK_REALTIME, mode: HRTIMER_MODE_REL);
596 bdata->debounce_timer.function = gpio_keys_debounce_timer;
597
598 isr = gpio_keys_gpio_isr;
599 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
600
601 switch (button->wakeup_event_action) {
602 case EV_ACT_ASSERTED:
603 bdata->wakeup_trigger_type = active_low ?
604 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
605 break;
606 case EV_ACT_DEASSERTED:
607 bdata->wakeup_trigger_type = active_low ?
608 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
609 break;
610 case EV_ACT_ANY:
611 default:
612 /*
613 * For other cases, we are OK letting suspend/resume
614 * not reconfigure the trigger type.
615 */
616 break;
617 }
618 } else {
619 if (!button->irq) {
620 dev_err(dev, "Found button without gpio or irq\n");
621 return -EINVAL;
622 }
623
624 bdata->irq = button->irq;
625
626 if (button->type && button->type != EV_KEY) {
627 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
628 return -EINVAL;
629 }
630
631 bdata->release_delay = button->debounce_interval;
632 hrtimer_init(timer: &bdata->release_timer,
633 CLOCK_REALTIME, mode: HRTIMER_MODE_REL_HARD);
634 bdata->release_timer.function = gpio_keys_irq_timer;
635
636 isr = gpio_keys_irq_isr;
637 irqflags = 0;
638
639 /*
640 * For IRQ buttons, there is no interrupt for release.
641 * So we don't need to reconfigure the trigger type for wakeup.
642 */
643 }
644
645 bdata->code = &ddata->keymap[idx];
646 *bdata->code = button->code;
647 input_set_capability(dev: input, type: button->type ?: EV_KEY, code: *bdata->code);
648
649 /*
650 * Install custom action to cancel release timer and
651 * workqueue item.
652 */
653 error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
654 if (error) {
655 dev_err(dev, "failed to register quiesce action, error: %d\n",
656 error);
657 return error;
658 }
659
660 /*
661 * If platform has specified that the button can be disabled,
662 * we don't want it to share the interrupt line.
663 */
664 if (!button->can_disable)
665 irqflags |= IRQF_SHARED;
666
667 error = devm_request_any_context_irq(dev, irq: bdata->irq, handler: isr, irqflags,
668 devname: desc, dev_id: bdata);
669 if (error < 0) {
670 dev_err(dev, "Unable to claim irq %d; error %d\n",
671 bdata->irq, error);
672 return error;
673 }
674
675 return 0;
676}
677
678static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
679{
680 struct input_dev *input = ddata->input;
681 int i;
682
683 for (i = 0; i < ddata->pdata->nbuttons; i++) {
684 struct gpio_button_data *bdata = &ddata->data[i];
685 if (bdata->gpiod)
686 gpio_keys_gpio_report_event(bdata);
687 }
688 input_sync(dev: input);
689}
690
691static int gpio_keys_open(struct input_dev *input)
692{
693 struct gpio_keys_drvdata *ddata = input_get_drvdata(dev: input);
694 const struct gpio_keys_platform_data *pdata = ddata->pdata;
695 int error;
696
697 if (pdata->enable) {
698 error = pdata->enable(input->dev.parent);
699 if (error)
700 return error;
701 }
702
703 /* Report current state of buttons that are connected to GPIOs */
704 gpio_keys_report_state(ddata);
705
706 return 0;
707}
708
709static void gpio_keys_close(struct input_dev *input)
710{
711 struct gpio_keys_drvdata *ddata = input_get_drvdata(dev: input);
712 const struct gpio_keys_platform_data *pdata = ddata->pdata;
713
714 if (pdata->disable)
715 pdata->disable(input->dev.parent);
716}
717
718/*
719 * Handlers for alternative sources of platform_data
720 */
721
722/*
723 * Translate properties into platform_data
724 */
725static struct gpio_keys_platform_data *
726gpio_keys_get_devtree_pdata(struct device *dev)
727{
728 struct gpio_keys_platform_data *pdata;
729 struct gpio_keys_button *button;
730 struct fwnode_handle *child;
731 int nbuttons;
732
733 nbuttons = device_get_child_node_count(dev);
734 if (nbuttons == 0)
735 return ERR_PTR(error: -ENODEV);
736
737 pdata = devm_kzalloc(dev,
738 size: sizeof(*pdata) + nbuttons * sizeof(*button),
739 GFP_KERNEL);
740 if (!pdata)
741 return ERR_PTR(error: -ENOMEM);
742
743 button = (struct gpio_keys_button *)(pdata + 1);
744
745 pdata->buttons = button;
746 pdata->nbuttons = nbuttons;
747
748 pdata->rep = device_property_read_bool(dev, propname: "autorepeat");
749
750 device_property_read_string(dev, propname: "label", val: &pdata->name);
751
752 device_for_each_child_node(dev, child) {
753 if (is_of_node(fwnode: child))
754 button->irq =
755 irq_of_parse_and_map(to_of_node(child), index: 0);
756
757 if (fwnode_property_read_u32(fwnode: child, propname: "linux,code",
758 val: &button->code)) {
759 dev_err(dev, "Button without keycode\n");
760 fwnode_handle_put(fwnode: child);
761 return ERR_PTR(error: -EINVAL);
762 }
763
764 fwnode_property_read_string(fwnode: child, propname: "label", val: &button->desc);
765
766 if (fwnode_property_read_u32(fwnode: child, propname: "linux,input-type",
767 val: &button->type))
768 button->type = EV_KEY;
769
770 fwnode_property_read_u32(fwnode: child, propname: "linux,input-value",
771 val: (u32 *)&button->value);
772
773 button->wakeup =
774 fwnode_property_read_bool(fwnode: child, propname: "wakeup-source") ||
775 /* legacy name */
776 fwnode_property_read_bool(fwnode: child, propname: "gpio-key,wakeup");
777
778 fwnode_property_read_u32(fwnode: child, propname: "wakeup-event-action",
779 val: &button->wakeup_event_action);
780
781 button->can_disable =
782 fwnode_property_read_bool(fwnode: child, propname: "linux,can-disable");
783
784 if (fwnode_property_read_u32(fwnode: child, propname: "debounce-interval",
785 val: &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(ptr: pdata))
813 return PTR_ERR(ptr: 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 n: pdata->nbuttons, size: 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, data: ddata);
840 input_set_drvdata(dev: input, data: 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, idx: i, child);
876 if (error) {
877 fwnode_handle_put(fwnode: child);
878 return error;
879 }
880
881 if (button->wakeup)
882 wakeup = 1;
883 }
884
885 fwnode_handle_put(fwnode: 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, enable: 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(irq: 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(irq: bdata->irq,
914 type: 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(irq: 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(irq: bdata->irq, type: 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(irq: 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(d: irq_get_irq_data(irq: 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(dev: input))
1008 gpio_keys_close(input);
1009 mutex_unlock(lock: &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(dev: input))
1026 error = gpio_keys_open(input);
1027 mutex_unlock(lock: &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(dev: &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");
1076

source code of linux/drivers/input/keyboard/gpio_keys.c