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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/init.h>
12#include <linux/fs.h>
13#include <linux/interrupt.h>
14#include <linux/irq.h>
15#include <linux/sched.h>
16#include <linux/pm.h>
17#include <linux/slab.h>
18#include <linux/sysctl.h>
19#include <linux/proc_fs.h>
20#include <linux/delay.h>
21#include <linux/platform_device.h>
22#include <linux/input.h>
23#include <linux/gpio_keys.h>
24#include <linux/workqueue.h>
25#include <linux/gpio.h>
26#include <linux/gpio/consumer.h>
27#include <linux/of.h>
28#include <linux/of_irq.h>
29#include <linux/spinlock.h>
30#include <dt-bindings/input/gpio-keys.h>
31
32struct gpio_button_data {
33 const struct gpio_keys_button *button;
34 struct input_dev *input;
35 struct gpio_desc *gpiod;
36
37 unsigned short *code;
38
39 struct timer_list release_timer;
40 unsigned int release_delay; /* in msecs, for IRQ-only buttons */
41
42 struct delayed_work work;
43 unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
44
45 unsigned int irq;
46 unsigned int wakeup_trigger_type;
47 spinlock_t lock;
48 bool disabled;
49 bool key_pressed;
50 bool suspended;
51};
52
53struct gpio_keys_drvdata {
54 const struct gpio_keys_platform_data *pdata;
55 struct input_dev *input;
56 struct mutex disable_lock;
57 unsigned short *keymap;
58 struct gpio_button_data data[];
59};
60
61/*
62 * SYSFS interface for enabling/disabling keys and switches:
63 *
64 * There are 4 attributes under /sys/devices/platform/gpio-keys/
65 * keys [ro] - bitmap of keys (EV_KEY) which can be
66 * disabled
67 * switches [ro] - bitmap of switches (EV_SW) which can be
68 * disabled
69 * disabled_keys [rw] - bitmap of keys currently disabled
70 * disabled_switches [rw] - bitmap of switches currently disabled
71 *
72 * Userland can change these values and hence disable event generation
73 * for each key (or switch). Disabling a key means its interrupt line
74 * is disabled.
75 *
76 * For example, if we have following switches set up as gpio-keys:
77 * SW_DOCK = 5
78 * SW_CAMERA_LENS_COVER = 9
79 * SW_KEYPAD_SLIDE = 10
80 * SW_FRONT_PROXIMITY = 11
81 * This is read from switches:
82 * 11-9,5
83 * Next we want to disable proximity (11) and dock (5), we write:
84 * 11,5
85 * to file disabled_switches. Now proximity and dock IRQs are disabled.
86 * This can be verified by reading the file disabled_switches:
87 * 11,5
88 * If we now want to enable proximity (11) switch we write:
89 * 5
90 * to disabled_switches.
91 *
92 * We can disable only those keys which don't allow sharing the irq.
93 */
94
95/**
96 * get_n_events_by_type() - returns maximum number of events per @type
97 * @type: type of button (%EV_KEY, %EV_SW)
98 *
99 * Return value of this function can be used to allocate bitmap
100 * large enough to hold all bits for given type.
101 */
102static int get_n_events_by_type(int type)
103{
104 BUG_ON(type != EV_SW && type != EV_KEY);
105
106 return (type == EV_KEY) ? KEY_CNT : SW_CNT;
107}
108
109/**
110 * get_bm_events_by_type() - returns bitmap of supported events per @type
111 * @input: input device from which bitmap is retrieved
112 * @type: type of button (%EV_KEY, %EV_SW)
113 *
114 * Return value of this function can be used to allocate bitmap
115 * large enough to hold all bits for given type.
116 */
117static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
118 int type)
119{
120 BUG_ON(type != EV_SW && type != EV_KEY);
121
122 return (type == EV_KEY) ? dev->keybit : dev->swbit;
123}
124
125/**
126 * gpio_keys_disable_button() - disables given GPIO button
127 * @bdata: button data for button to be disabled
128 *
129 * Disables button pointed by @bdata. This is done by masking
130 * IRQ line. After this function is called, button won't generate
131 * input events anymore. Note that one can only disable buttons
132 * that don't share IRQs.
133 *
134 * Make sure that @bdata->disable_lock is locked when entering
135 * this function to avoid races when concurrent threads are
136 * disabling buttons at the same time.
137 */
138static void gpio_keys_disable_button(struct gpio_button_data *bdata)
139{
140 if (!bdata->disabled) {
141 /*
142 * Disable IRQ and associated timer/work structure.
143 */
144 disable_irq(bdata->irq);
145
146 if (bdata->gpiod)
147 cancel_delayed_work_sync(&bdata->work);
148 else
149 del_timer_sync(&bdata->release_timer);
150
151 bdata->disabled = true;
152 }
153}
154
155/**
156 * gpio_keys_enable_button() - enables given GPIO button
157 * @bdata: button data for button to be disabled
158 *
159 * Enables given button pointed by @bdata.
160 *
161 * Make sure that @bdata->disable_lock is locked when entering
162 * this function to avoid races with concurrent threads trying
163 * to enable the same button at the same time.
164 */
165static void gpio_keys_enable_button(struct gpio_button_data *bdata)
166{
167 if (bdata->disabled) {
168 enable_irq(bdata->irq);
169 bdata->disabled = false;
170 }
171}
172
173/**
174 * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
175 * @ddata: pointer to drvdata
176 * @buf: buffer where stringified bitmap is written
177 * @type: button type (%EV_KEY, %EV_SW)
178 * @only_disabled: does caller want only those buttons that are
179 * currently disabled or all buttons that can be
180 * disabled
181 *
182 * This function writes buttons that can be disabled to @buf. If
183 * @only_disabled is true, then @buf contains only those buttons
184 * that are currently disabled. Returns 0 on success or negative
185 * errno on failure.
186 */
187static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
188 char *buf, unsigned int type,
189 bool only_disabled)
190{
191 int n_events = get_n_events_by_type(type);
192 unsigned long *bits;
193 ssize_t ret;
194 int i;
195
196 bits = bitmap_zalloc(n_events, GFP_KERNEL);
197 if (!bits)
198 return -ENOMEM;
199
200 for (i = 0; i < ddata->pdata->nbuttons; i++) {
201 struct gpio_button_data *bdata = &ddata->data[i];
202
203 if (bdata->button->type != type)
204 continue;
205
206 if (only_disabled && !bdata->disabled)
207 continue;
208
209 __set_bit(*bdata->code, bits);
210 }
211
212 ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
213 buf[ret++] = '\n';
214 buf[ret] = '\0';
215
216 bitmap_free(bits);
217
218 return ret;
219}
220
221/**
222 * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
223 * @ddata: pointer to drvdata
224 * @buf: buffer from userspace that contains stringified bitmap
225 * @type: button type (%EV_KEY, %EV_SW)
226 *
227 * This function parses stringified bitmap from @buf and disables/enables
228 * GPIO buttons accordingly. Returns 0 on success and negative error
229 * on failure.
230 */
231static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
232 const char *buf, unsigned int type)
233{
234 int n_events = get_n_events_by_type(type);
235 const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
236 unsigned long *bits;
237 ssize_t error;
238 int i;
239
240 bits = bitmap_zalloc(n_events, GFP_KERNEL);
241 if (!bits)
242 return -ENOMEM;
243
244 error = bitmap_parselist(buf, bits, n_events);
245 if (error)
246 goto out;
247
248 /* First validate */
249 if (!bitmap_subset(bits, bitmap, n_events)) {
250 error = -EINVAL;
251 goto out;
252 }
253
254 for (i = 0; i < ddata->pdata->nbuttons; i++) {
255 struct gpio_button_data *bdata = &ddata->data[i];
256
257 if (bdata->button->type != type)
258 continue;
259
260 if (test_bit(*bdata->code, bits) &&
261 !bdata->button->can_disable) {
262 error = -EINVAL;
263 goto out;
264 }
265 }
266
267 mutex_lock(&ddata->disable_lock);
268
269 for (i = 0; i < ddata->pdata->nbuttons; i++) {
270 struct gpio_button_data *bdata = &ddata->data[i];
271
272 if (bdata->button->type != type)
273 continue;
274
275 if (test_bit(*bdata->code, bits))
276 gpio_keys_disable_button(bdata);
277 else
278 gpio_keys_enable_button(bdata);
279 }
280
281 mutex_unlock(&ddata->disable_lock);
282
283out:
284 bitmap_free(bits);
285 return error;
286}
287
288#define ATTR_SHOW_FN(name, type, only_disabled) \
289static ssize_t gpio_keys_show_##name(struct device *dev, \
290 struct device_attribute *attr, \
291 char *buf) \
292{ \
293 struct platform_device *pdev = to_platform_device(dev); \
294 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
295 \
296 return gpio_keys_attr_show_helper(ddata, buf, \
297 type, only_disabled); \
298}
299
300ATTR_SHOW_FN(keys, EV_KEY, false);
301ATTR_SHOW_FN(switches, EV_SW, false);
302ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
303ATTR_SHOW_FN(disabled_switches, EV_SW, true);
304
305/*
306 * ATTRIBUTES:
307 *
308 * /sys/devices/platform/gpio-keys/keys [ro]
309 * /sys/devices/platform/gpio-keys/switches [ro]
310 */
311static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
312static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
313
314#define ATTR_STORE_FN(name, type) \
315static ssize_t gpio_keys_store_##name(struct device *dev, \
316 struct device_attribute *attr, \
317 const char *buf, \
318 size_t count) \
319{ \
320 struct platform_device *pdev = to_platform_device(dev); \
321 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
322 ssize_t error; \
323 \
324 error = gpio_keys_attr_store_helper(ddata, buf, type); \
325 if (error) \
326 return error; \
327 \
328 return count; \
329}
330
331ATTR_STORE_FN(disabled_keys, EV_KEY);
332ATTR_STORE_FN(disabled_switches, EV_SW);
333
334/*
335 * ATTRIBUTES:
336 *
337 * /sys/devices/platform/gpio-keys/disabled_keys [rw]
338 * /sys/devices/platform/gpio-keys/disables_switches [rw]
339 */
340static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
341 gpio_keys_show_disabled_keys,
342 gpio_keys_store_disabled_keys);
343static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
344 gpio_keys_show_disabled_switches,
345 gpio_keys_store_disabled_switches);
346
347static struct attribute *gpio_keys_attrs[] = {
348 &dev_attr_keys.attr,
349 &dev_attr_switches.attr,
350 &dev_attr_disabled_keys.attr,
351 &dev_attr_disabled_switches.attr,
352 NULL,
353};
354ATTRIBUTE_GROUPS(gpio_keys);
355
356static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
357{
358 const struct gpio_keys_button *button = bdata->button;
359 struct input_dev *input = bdata->input;
360 unsigned int type = button->type ?: EV_KEY;
361 int state;
362
363 state = gpiod_get_value_cansleep(bdata->gpiod);
364 if (state < 0) {
365 dev_err(input->dev.parent,
366 "failed to get gpio state: %d\n", state);
367 return;
368 }
369
370 if (type == EV_ABS) {
371 if (state)
372 input_event(input, type, button->code, button->value);
373 } else {
374 input_event(input, type, *bdata->code, state);
375 }
376 input_sync(input);
377}
378
379static void gpio_keys_gpio_work_func(struct work_struct *work)
380{
381 struct gpio_button_data *bdata =
382 container_of(work, struct gpio_button_data, work.work);
383
384 gpio_keys_gpio_report_event(bdata);
385
386 if (bdata->button->wakeup)
387 pm_relax(bdata->input->dev.parent);
388}
389
390static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
391{
392 struct gpio_button_data *bdata = dev_id;
393
394 BUG_ON(irq != bdata->irq);
395
396 if (bdata->button->wakeup) {
397 const struct gpio_keys_button *button = bdata->button;
398
399 pm_stay_awake(bdata->input->dev.parent);
400 if (bdata->suspended &&
401 (button->type == 0 || button->type == EV_KEY)) {
402 /*
403 * Simulate wakeup key press in case the key has
404 * already released by the time we got interrupt
405 * handler to run.
406 */
407 input_report_key(bdata->input, button->code, 1);
408 }
409 }
410
411 mod_delayed_work(system_wq,
412 &bdata->work,
413 msecs_to_jiffies(bdata->software_debounce));
414
415 return IRQ_HANDLED;
416}
417
418static void gpio_keys_irq_timer(struct timer_list *t)
419{
420 struct gpio_button_data *bdata = from_timer(bdata, t, release_timer);
421 struct input_dev *input = bdata->input;
422 unsigned long flags;
423
424 spin_lock_irqsave(&bdata->lock, flags);
425 if (bdata->key_pressed) {
426 input_event(input, EV_KEY, *bdata->code, 0);
427 input_sync(input);
428 bdata->key_pressed = false;
429 }
430 spin_unlock_irqrestore(&bdata->lock, flags);
431}
432
433static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
434{
435 struct gpio_button_data *bdata = dev_id;
436 struct input_dev *input = bdata->input;
437 unsigned long flags;
438
439 BUG_ON(irq != bdata->irq);
440
441 spin_lock_irqsave(&bdata->lock, flags);
442
443 if (!bdata->key_pressed) {
444 if (bdata->button->wakeup)
445 pm_wakeup_event(bdata->input->dev.parent, 0);
446
447 input_event(input, EV_KEY, *bdata->code, 1);
448 input_sync(input);
449
450 if (!bdata->release_delay) {
451 input_event(input, EV_KEY, *bdata->code, 0);
452 input_sync(input);
453 goto out;
454 }
455
456 bdata->key_pressed = true;
457 }
458
459 if (bdata->release_delay)
460 mod_timer(&bdata->release_timer,
461 jiffies + msecs_to_jiffies(bdata->release_delay));
462out:
463 spin_unlock_irqrestore(&bdata->lock, flags);
464 return IRQ_HANDLED;
465}
466
467static void gpio_keys_quiesce_key(void *data)
468{
469 struct gpio_button_data *bdata = data;
470
471 if (bdata->gpiod)
472 cancel_delayed_work_sync(&bdata->work);
473 else
474 del_timer_sync(&bdata->release_timer);
475}
476
477static int gpio_keys_setup_key(struct platform_device *pdev,
478 struct input_dev *input,
479 struct gpio_keys_drvdata *ddata,
480 const struct gpio_keys_button *button,
481 int idx,
482 struct fwnode_handle *child)
483{
484 const char *desc = button->desc ? button->desc : "gpio_keys";
485 struct device *dev = &pdev->dev;
486 struct gpio_button_data *bdata = &ddata->data[idx];
487 irq_handler_t isr;
488 unsigned long irqflags;
489 int irq;
490 int error;
491
492 bdata->input = input;
493 bdata->button = button;
494 spin_lock_init(&bdata->lock);
495
496 if (child) {
497 bdata->gpiod = devm_fwnode_gpiod_get(dev, child,
498 NULL, GPIOD_IN, desc);
499 if (IS_ERR(bdata->gpiod)) {
500 error = PTR_ERR(bdata->gpiod);
501 if (error == -ENOENT) {
502 /*
503 * GPIO is optional, we may be dealing with
504 * purely interrupt-driven setup.
505 */
506 bdata->gpiod = NULL;
507 } else {
508 if (error != -EPROBE_DEFER)
509 dev_err(dev, "failed to get gpio: %d\n",
510 error);
511 return error;
512 }
513 }
514 } else if (gpio_is_valid(button->gpio)) {
515 /*
516 * Legacy GPIO number, so request the GPIO here and
517 * convert it to descriptor.
518 */
519 unsigned flags = GPIOF_IN;
520
521 if (button->active_low)
522 flags |= GPIOF_ACTIVE_LOW;
523
524 error = devm_gpio_request_one(dev, button->gpio, flags, desc);
525 if (error < 0) {
526 dev_err(dev, "Failed to request GPIO %d, error %d\n",
527 button->gpio, error);
528 return error;
529 }
530
531 bdata->gpiod = gpio_to_desc(button->gpio);
532 if (!bdata->gpiod)
533 return -EINVAL;
534 }
535
536 if (bdata->gpiod) {
537 bool active_low = gpiod_is_active_low(bdata->gpiod);
538
539 if (button->debounce_interval) {
540 error = gpiod_set_debounce(bdata->gpiod,
541 button->debounce_interval * 1000);
542 /* use timer if gpiolib doesn't provide debounce */
543 if (error < 0)
544 bdata->software_debounce =
545 button->debounce_interval;
546 }
547
548 if (button->irq) {
549 bdata->irq = button->irq;
550 } else {
551 irq = gpiod_to_irq(bdata->gpiod);
552 if (irq < 0) {
553 error = irq;
554 dev_err(dev,
555 "Unable to get irq number for GPIO %d, error %d\n",
556 button->gpio, error);
557 return error;
558 }
559 bdata->irq = irq;
560 }
561
562 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
563
564 isr = gpio_keys_gpio_isr;
565 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
566
567 switch (button->wakeup_event_action) {
568 case EV_ACT_ASSERTED:
569 bdata->wakeup_trigger_type = active_low ?
570 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
571 break;
572 case EV_ACT_DEASSERTED:
573 bdata->wakeup_trigger_type = active_low ?
574 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
575 break;
576 case EV_ACT_ANY:
577 default:
578 /*
579 * For other cases, we are OK letting suspend/resume
580 * not reconfigure the trigger type.
581 */
582 break;
583 }
584 } else {
585 if (!button->irq) {
586 dev_err(dev, "Found button without gpio or irq\n");
587 return -EINVAL;
588 }
589
590 bdata->irq = button->irq;
591
592 if (button->type && button->type != EV_KEY) {
593 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
594 return -EINVAL;
595 }
596
597 bdata->release_delay = button->debounce_interval;
598 timer_setup(&bdata->release_timer, gpio_keys_irq_timer, 0);
599
600 isr = gpio_keys_irq_isr;
601 irqflags = 0;
602
603 /*
604 * For IRQ buttons, there is no interrupt for release.
605 * So we don't need to reconfigure the trigger type for wakeup.
606 */
607 }
608
609 bdata->code = &ddata->keymap[idx];
610 *bdata->code = button->code;
611 input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
612
613 /*
614 * Install custom action to cancel release timer and
615 * workqueue item.
616 */
617 error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
618 if (error) {
619 dev_err(dev, "failed to register quiesce action, error: %d\n",
620 error);
621 return error;
622 }
623
624 /*
625 * If platform has specified that the button can be disabled,
626 * we don't want it to share the interrupt line.
627 */
628 if (!button->can_disable)
629 irqflags |= IRQF_SHARED;
630
631 error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
632 desc, bdata);
633 if (error < 0) {
634 dev_err(dev, "Unable to claim irq %d; error %d\n",
635 bdata->irq, error);
636 return error;
637 }
638
639 return 0;
640}
641
642static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
643{
644 struct input_dev *input = ddata->input;
645 int i;
646
647 for (i = 0; i < ddata->pdata->nbuttons; i++) {
648 struct gpio_button_data *bdata = &ddata->data[i];
649 if (bdata->gpiod)
650 gpio_keys_gpio_report_event(bdata);
651 }
652 input_sync(input);
653}
654
655static int gpio_keys_open(struct input_dev *input)
656{
657 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
658 const struct gpio_keys_platform_data *pdata = ddata->pdata;
659 int error;
660
661 if (pdata->enable) {
662 error = pdata->enable(input->dev.parent);
663 if (error)
664 return error;
665 }
666
667 /* Report current state of buttons that are connected to GPIOs */
668 gpio_keys_report_state(ddata);
669
670 return 0;
671}
672
673static void gpio_keys_close(struct input_dev *input)
674{
675 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
676 const struct gpio_keys_platform_data *pdata = ddata->pdata;
677
678 if (pdata->disable)
679 pdata->disable(input->dev.parent);
680}
681
682/*
683 * Handlers for alternative sources of platform_data
684 */
685
686/*
687 * Translate properties into platform_data
688 */
689static struct gpio_keys_platform_data *
690gpio_keys_get_devtree_pdata(struct device *dev)
691{
692 struct gpio_keys_platform_data *pdata;
693 struct gpio_keys_button *button;
694 struct fwnode_handle *child;
695 int nbuttons;
696
697 nbuttons = device_get_child_node_count(dev);
698 if (nbuttons == 0)
699 return ERR_PTR(-ENODEV);
700
701 pdata = devm_kzalloc(dev,
702 sizeof(*pdata) + nbuttons * sizeof(*button),
703 GFP_KERNEL);
704 if (!pdata)
705 return ERR_PTR(-ENOMEM);
706
707 button = (struct gpio_keys_button *)(pdata + 1);
708
709 pdata->buttons = button;
710 pdata->nbuttons = nbuttons;
711
712 pdata->rep = device_property_read_bool(dev, "autorepeat");
713
714 device_property_read_string(dev, "label", &pdata->name);
715
716 device_for_each_child_node(dev, child) {
717 if (is_of_node(child))
718 button->irq =
719 irq_of_parse_and_map(to_of_node(child), 0);
720
721 if (fwnode_property_read_u32(child, "linux,code",
722 &button->code)) {
723 dev_err(dev, "Button without keycode\n");
724 fwnode_handle_put(child);
725 return ERR_PTR(-EINVAL);
726 }
727
728 fwnode_property_read_string(child, "label", &button->desc);
729
730 if (fwnode_property_read_u32(child, "linux,input-type",
731 &button->type))
732 button->type = EV_KEY;
733
734 button->wakeup =
735 fwnode_property_read_bool(child, "wakeup-source") ||
736 /* legacy name */
737 fwnode_property_read_bool(child, "gpio-key,wakeup");
738
739 fwnode_property_read_u32(child, "wakeup-event-action",
740 &button->wakeup_event_action);
741
742 button->can_disable =
743 fwnode_property_read_bool(child, "linux,can-disable");
744
745 if (fwnode_property_read_u32(child, "debounce-interval",
746 &button->debounce_interval))
747 button->debounce_interval = 5;
748
749 button++;
750 }
751
752 return pdata;
753}
754
755static const struct of_device_id gpio_keys_of_match[] = {
756 { .compatible = "gpio-keys", },
757 { },
758};
759MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
760
761static int gpio_keys_probe(struct platform_device *pdev)
762{
763 struct device *dev = &pdev->dev;
764 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
765 struct fwnode_handle *child = NULL;
766 struct gpio_keys_drvdata *ddata;
767 struct input_dev *input;
768 int i, error;
769 int wakeup = 0;
770
771 if (!pdata) {
772 pdata = gpio_keys_get_devtree_pdata(dev);
773 if (IS_ERR(pdata))
774 return PTR_ERR(pdata);
775 }
776
777 ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
778 GFP_KERNEL);
779 if (!ddata) {
780 dev_err(dev, "failed to allocate state\n");
781 return -ENOMEM;
782 }
783
784 ddata->keymap = devm_kcalloc(dev,
785 pdata->nbuttons, sizeof(ddata->keymap[0]),
786 GFP_KERNEL);
787 if (!ddata->keymap)
788 return -ENOMEM;
789
790 input = devm_input_allocate_device(dev);
791 if (!input) {
792 dev_err(dev, "failed to allocate input device\n");
793 return -ENOMEM;
794 }
795
796 ddata->pdata = pdata;
797 ddata->input = input;
798 mutex_init(&ddata->disable_lock);
799
800 platform_set_drvdata(pdev, ddata);
801 input_set_drvdata(input, ddata);
802
803 input->name = pdata->name ? : pdev->name;
804 input->phys = "gpio-keys/input0";
805 input->dev.parent = dev;
806 input->open = gpio_keys_open;
807 input->close = gpio_keys_close;
808
809 input->id.bustype = BUS_HOST;
810 input->id.vendor = 0x0001;
811 input->id.product = 0x0001;
812 input->id.version = 0x0100;
813
814 input->keycode = ddata->keymap;
815 input->keycodesize = sizeof(ddata->keymap[0]);
816 input->keycodemax = pdata->nbuttons;
817
818 /* Enable auto repeat feature of Linux input subsystem */
819 if (pdata->rep)
820 __set_bit(EV_REP, input->evbit);
821
822 for (i = 0; i < pdata->nbuttons; i++) {
823 const struct gpio_keys_button *button = &pdata->buttons[i];
824
825 if (!dev_get_platdata(dev)) {
826 child = device_get_next_child_node(dev, child);
827 if (!child) {
828 dev_err(dev,
829 "missing child device node for entry %d\n",
830 i);
831 return -EINVAL;
832 }
833 }
834
835 error = gpio_keys_setup_key(pdev, input, ddata,
836 button, i, child);
837 if (error) {
838 fwnode_handle_put(child);
839 return error;
840 }
841
842 if (button->wakeup)
843 wakeup = 1;
844 }
845
846 fwnode_handle_put(child);
847
848 error = input_register_device(input);
849 if (error) {
850 dev_err(dev, "Unable to register input device, error: %d\n",
851 error);
852 return error;
853 }
854
855 device_init_wakeup(dev, wakeup);
856
857 return 0;
858}
859
860static int __maybe_unused
861gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
862{
863 int error;
864
865 error = enable_irq_wake(bdata->irq);
866 if (error) {
867 dev_err(bdata->input->dev.parent,
868 "failed to configure IRQ %d as wakeup source: %d\n",
869 bdata->irq, error);
870 return error;
871 }
872
873 if (bdata->wakeup_trigger_type) {
874 error = irq_set_irq_type(bdata->irq,
875 bdata->wakeup_trigger_type);
876 if (error) {
877 dev_err(bdata->input->dev.parent,
878 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
879 bdata->wakeup_trigger_type, bdata->irq, error);
880 disable_irq_wake(bdata->irq);
881 return error;
882 }
883 }
884
885 return 0;
886}
887
888static void __maybe_unused
889gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
890{
891 int error;
892
893 /*
894 * The trigger type is always both edges for gpio-based keys and we do
895 * not support changing wakeup trigger for interrupt-based keys.
896 */
897 if (bdata->wakeup_trigger_type) {
898 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
899 if (error)
900 dev_warn(bdata->input->dev.parent,
901 "failed to restore interrupt trigger for IRQ %d: %d\n",
902 bdata->irq, error);
903 }
904
905 error = disable_irq_wake(bdata->irq);
906 if (error)
907 dev_warn(bdata->input->dev.parent,
908 "failed to disable IRQ %d as wake source: %d\n",
909 bdata->irq, error);
910}
911
912static int __maybe_unused
913gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
914{
915 struct gpio_button_data *bdata;
916 int error;
917 int i;
918
919 for (i = 0; i < ddata->pdata->nbuttons; i++) {
920 bdata = &ddata->data[i];
921 if (bdata->button->wakeup) {
922 error = gpio_keys_button_enable_wakeup(bdata);
923 if (error)
924 goto err_out;
925 }
926 bdata->suspended = true;
927 }
928
929 return 0;
930
931err_out:
932 while (i--) {
933 bdata = &ddata->data[i];
934 if (bdata->button->wakeup)
935 gpio_keys_button_disable_wakeup(bdata);
936 bdata->suspended = false;
937 }
938
939 return error;
940}
941
942static void __maybe_unused
943gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
944{
945 struct gpio_button_data *bdata;
946 int i;
947
948 for (i = 0; i < ddata->pdata->nbuttons; i++) {
949 bdata = &ddata->data[i];
950 bdata->suspended = false;
951 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
952 gpio_keys_button_disable_wakeup(bdata);
953 }
954}
955
956static int __maybe_unused gpio_keys_suspend(struct device *dev)
957{
958 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
959 struct input_dev *input = ddata->input;
960 int error;
961
962 if (device_may_wakeup(dev)) {
963 error = gpio_keys_enable_wakeup(ddata);
964 if (error)
965 return error;
966 } else {
967 mutex_lock(&input->mutex);
968 if (input->users)
969 gpio_keys_close(input);
970 mutex_unlock(&input->mutex);
971 }
972
973 return 0;
974}
975
976static int __maybe_unused gpio_keys_resume(struct device *dev)
977{
978 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
979 struct input_dev *input = ddata->input;
980 int error = 0;
981
982 if (device_may_wakeup(dev)) {
983 gpio_keys_disable_wakeup(ddata);
984 } else {
985 mutex_lock(&input->mutex);
986 if (input->users)
987 error = gpio_keys_open(input);
988 mutex_unlock(&input->mutex);
989 }
990
991 if (error)
992 return error;
993
994 gpio_keys_report_state(ddata);
995 return 0;
996}
997
998static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
999
1000static void gpio_keys_shutdown(struct platform_device *pdev)
1001{
1002 int ret;
1003
1004 ret = gpio_keys_suspend(&pdev->dev);
1005 if (ret)
1006 dev_err(&pdev->dev, "failed to shutdown\n");
1007}
1008
1009static struct platform_driver gpio_keys_device_driver = {
1010 .probe = gpio_keys_probe,
1011 .shutdown = gpio_keys_shutdown,
1012 .driver = {
1013 .name = "gpio-keys",
1014 .pm = &gpio_keys_pm_ops,
1015 .of_match_table = gpio_keys_of_match,
1016 .dev_groups = gpio_keys_groups,
1017 }
1018};
1019
1020static int __init gpio_keys_init(void)
1021{
1022 return platform_driver_register(&gpio_keys_device_driver);
1023}
1024
1025static void __exit gpio_keys_exit(void)
1026{
1027 platform_driver_unregister(&gpio_keys_device_driver);
1028}
1029
1030late_initcall(gpio_keys_init);
1031module_exit(gpio_keys_exit);
1032
1033MODULE_LICENSE("GPL");
1034MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1035MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1036MODULE_ALIAS("platform:gpio-keys");
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");