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