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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/of.h>
30#include <linux/of_platform.h>
31#include <linux/of_gpio.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 timer_list timer;
38 struct work_struct work;
39 unsigned int timer_debounce; /* in msecs */
40 unsigned int irq;
41 spinlock_t lock;
42 bool disabled;
43 bool key_pressed;
44};
45
46struct gpio_keys_drvdata {
47 const struct gpio_keys_platform_data *pdata;
48 struct input_dev *input;
49 struct mutex disable_lock;
50 struct gpio_button_data data[0];
51};
52
53/*
54 * SYSFS interface for enabling/disabling keys and switches:
55 *
56 * There are 4 attributes under /sys/devices/platform/gpio-keys/
57 * keys [ro] - bitmap of keys (EV_KEY) which can be
58 * disabled
59 * switches [ro] - bitmap of switches (EV_SW) which can be
60 * disabled
61 * disabled_keys [rw] - bitmap of keys currently disabled
62 * disabled_switches [rw] - bitmap of switches currently disabled
63 *
64 * Userland can change these values and hence disable event generation
65 * for each key (or switch). Disabling a key means its interrupt line
66 * is disabled.
67 *
68 * For example, if we have following switches set up as gpio-keys:
69 * SW_DOCK = 5
70 * SW_CAMERA_LENS_COVER = 9
71 * SW_KEYPAD_SLIDE = 10
72 * SW_FRONT_PROXIMITY = 11
73 * This is read from switches:
74 * 11-9,5
75 * Next we want to disable proximity (11) and dock (5), we write:
76 * 11,5
77 * to file disabled_switches. Now proximity and dock IRQs are disabled.
78 * This can be verified by reading the file disabled_switches:
79 * 11,5
80 * If we now want to enable proximity (11) switch we write:
81 * 5
82 * to disabled_switches.
83 *
84 * We can disable only those keys which don't allow sharing the irq.
85 */
86
87/**
88 * get_n_events_by_type() - returns maximum number of events per @type
89 * @type: type of button (%EV_KEY, %EV_SW)
90 *
91 * Return value of this function can be used to allocate bitmap
92 * large enough to hold all bits for given type.
93 */
94static inline int get_n_events_by_type(int type)
95{
96 BUG_ON(type != EV_SW && type != EV_KEY);
97
98 return (type == EV_KEY) ? KEY_CNT : SW_CNT;
99}
100
101/**
102 * gpio_keys_disable_button() - disables given GPIO button
103 * @bdata: button data for button to be disabled
104 *
105 * Disables button pointed by @bdata. This is done by masking
106 * IRQ line. After this function is called, button won't generate
107 * input events anymore. Note that one can only disable buttons
108 * that don't share IRQs.
109 *
110 * Make sure that @bdata->disable_lock is locked when entering
111 * this function to avoid races when concurrent threads are
112 * disabling buttons at the same time.
113 */
114static void gpio_keys_disable_button(struct gpio_button_data *bdata)
115{
116 if (!bdata->disabled) {
117 /*
118 * Disable IRQ and possible debouncing timer.
119 */
120 disable_irq(bdata->irq);
121 if (bdata->timer_debounce)
122 del_timer_sync(&bdata->timer);
123
124 bdata->disabled = true;
125 }
126}
127
128/**
129 * gpio_keys_enable_button() - enables given GPIO button
130 * @bdata: button data for button to be disabled
131 *
132 * Enables given button pointed by @bdata.
133 *
134 * Make sure that @bdata->disable_lock is locked when entering
135 * this function to avoid races with concurrent threads trying
136 * to enable the same button at the same time.
137 */
138static void gpio_keys_enable_button(struct gpio_button_data *bdata)
139{
140 if (bdata->disabled) {
141 enable_irq(bdata->irq);
142 bdata->disabled = false;
143 }
144}
145
146/**
147 * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
148 * @ddata: pointer to drvdata
149 * @buf: buffer where stringified bitmap is written
150 * @type: button type (%EV_KEY, %EV_SW)
151 * @only_disabled: does caller want only those buttons that are
152 * currently disabled or all buttons that can be
153 * disabled
154 *
155 * This function writes buttons that can be disabled to @buf. If
156 * @only_disabled is true, then @buf contains only those buttons
157 * that are currently disabled. Returns 0 on success or negative
158 * errno on failure.
159 */
160static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
161 char *buf, unsigned int type,
162 bool only_disabled)
163{
164 int n_events = get_n_events_by_type(type);
165 unsigned long *bits;
166 ssize_t ret;
167 int i;
168
169 bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
170 if (!bits)
171 return -ENOMEM;
172
173 for (i = 0; i < ddata->pdata->nbuttons; i++) {
174 struct gpio_button_data *bdata = &ddata->data[i];
175
176 if (bdata->button->type != type)
177 continue;
178
179 if (only_disabled && !bdata->disabled)
180 continue;
181
182 __set_bit(bdata->button->code, bits);
183 }
184
185 ret = bitmap_scnlistprintf(buf, PAGE_SIZE - 2, bits, n_events);
186 buf[ret++] = '\n';
187 buf[ret] = '\0';
188
189 kfree(bits);
190
191 return ret;
192}
193
194/**
195 * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
196 * @ddata: pointer to drvdata
197 * @buf: buffer from userspace that contains stringified bitmap
198 * @type: button type (%EV_KEY, %EV_SW)
199 *
200 * This function parses stringified bitmap from @buf and disables/enables
201 * GPIO buttons accordingly. Returns 0 on success and negative error
202 * on failure.
203 */
204static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
205 const char *buf, unsigned int type)
206{
207 int n_events = get_n_events_by_type(type);
208 unsigned long *bits;
209 ssize_t error;
210 int i;
211
212 bits = kcalloc(BITS_TO_LONGS(n_events), sizeof(*bits), GFP_KERNEL);
213 if (!bits)
214 return -ENOMEM;
215
216 error = bitmap_parselist(buf, bits, n_events);
217 if (error)
218 goto out;
219
220 /* First validate */
221 for (i = 0; i < ddata->pdata->nbuttons; i++) {
222 struct gpio_button_data *bdata = &ddata->data[i];
223
224 if (bdata->button->type != type)
225 continue;
226
227 if (test_bit(bdata->button->code, bits) &&
228 !bdata->button->can_disable) {
229 error = -EINVAL;
230 goto out;
231 }
232 }
233
234 mutex_lock(&ddata->disable_lock);
235
236 for (i = 0; i < ddata->pdata->nbuttons; i++) {
237 struct gpio_button_data *bdata = &ddata->data[i];
238
239 if (bdata->button->type != type)
240 continue;
241
242 if (test_bit(bdata->button->code, bits))
243 gpio_keys_disable_button(bdata);
244 else
245 gpio_keys_enable_button(bdata);
246 }
247
248 mutex_unlock(&ddata->disable_lock);
249
250out:
251 kfree(bits);
252 return error;
253}
254
255#define ATTR_SHOW_FN(name, type, only_disabled) \
256static ssize_t gpio_keys_show_##name(struct device *dev, \
257 struct device_attribute *attr, \
258 char *buf) \
259{ \
260 struct platform_device *pdev = to_platform_device(dev); \
261 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
262 \
263 return gpio_keys_attr_show_helper(ddata, buf, \
264 type, only_disabled); \
265}
266
267ATTR_SHOW_FN(keys, EV_KEY, false);
268ATTR_SHOW_FN(switches, EV_SW, false);
269ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
270ATTR_SHOW_FN(disabled_switches, EV_SW, true);
271
272/*
273 * ATTRIBUTES:
274 *
275 * /sys/devices/platform/gpio-keys/keys [ro]
276 * /sys/devices/platform/gpio-keys/switches [ro]
277 */
278static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
279static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
280
281#define ATTR_STORE_FN(name, type) \
282static ssize_t gpio_keys_store_##name(struct device *dev, \
283 struct device_attribute *attr, \
284 const char *buf, \
285 size_t count) \
286{ \
287 struct platform_device *pdev = to_platform_device(dev); \
288 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
289 ssize_t error; \
290 \
291 error = gpio_keys_attr_store_helper(ddata, buf, type); \
292 if (error) \
293 return error; \
294 \
295 return count; \
296}
297
298ATTR_STORE_FN(disabled_keys, EV_KEY);
299ATTR_STORE_FN(disabled_switches, EV_SW);
300
301/*
302 * ATTRIBUTES:
303 *
304 * /sys/devices/platform/gpio-keys/disabled_keys [rw]
305 * /sys/devices/platform/gpio-keys/disables_switches [rw]
306 */
307static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
308 gpio_keys_show_disabled_keys,
309 gpio_keys_store_disabled_keys);
310static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
311 gpio_keys_show_disabled_switches,
312 gpio_keys_store_disabled_switches);
313
314static struct attribute *gpio_keys_attrs[] = {
315 &dev_attr_keys.attr,
316 &dev_attr_switches.attr,
317 &dev_attr_disabled_keys.attr,
318 &dev_attr_disabled_switches.attr,
319 NULL,
320};
321
322static struct attribute_group gpio_keys_attr_group = {
323 .attrs = gpio_keys_attrs,
324};
325
326static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
327{
328 const struct gpio_keys_button *button = bdata->button;
329 struct input_dev *input = bdata->input;
330 unsigned int type = button->type ?: EV_KEY;
331 int state = (gpio_get_value_cansleep(button->gpio) ? 1 : 0) ^ button->active_low;
332
333 if (type == EV_ABS) {
334 if (state)
335 input_event(input, type, button->code, button->value);
336 } else {
337 input_event(input, type, button->code, !!state);
338 }
339 input_sync(input);
340}
341
342static void gpio_keys_gpio_work_func(struct work_struct *work)
343{
344 struct gpio_button_data *bdata =
345 container_of(work, struct gpio_button_data, work);
346
347 gpio_keys_gpio_report_event(bdata);
348
349 if (bdata->button->wakeup)
350 pm_relax(bdata->input->dev.parent);
351}
352
353static void gpio_keys_gpio_timer(unsigned long _data)
354{
355 struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
356
357 schedule_work(&bdata->work);
358}
359
360static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
361{
362 struct gpio_button_data *bdata = dev_id;
363
364 BUG_ON(irq != bdata->irq);
365
366 if (bdata->button->wakeup)
367 pm_stay_awake(bdata->input->dev.parent);
368 if (bdata->timer_debounce)
369 mod_timer(&bdata->timer,
370 jiffies + msecs_to_jiffies(bdata->timer_debounce));
371 else
372 schedule_work(&bdata->work);
373
374 return IRQ_HANDLED;
375}
376
377static void gpio_keys_irq_timer(unsigned long _data)
378{
379 struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
380 struct input_dev *input = bdata->input;
381 unsigned long flags;
382
383 spin_lock_irqsave(&bdata->lock, flags);
384 if (bdata->key_pressed) {
385 input_event(input, EV_KEY, bdata->button->code, 0);
386 input_sync(input);
387 bdata->key_pressed = false;
388 }
389 spin_unlock_irqrestore(&bdata->lock, flags);
390}
391
392static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
393{
394 struct gpio_button_data *bdata = dev_id;
395 const struct gpio_keys_button *button = bdata->button;
396 struct input_dev *input = bdata->input;
397 unsigned long flags;
398
399 BUG_ON(irq != bdata->irq);
400
401 spin_lock_irqsave(&bdata->lock, flags);
402
403 if (!bdata->key_pressed) {
404 if (bdata->button->wakeup)
405 pm_wakeup_event(bdata->input->dev.parent, 0);
406
407 input_event(input, EV_KEY, button->code, 1);
408 input_sync(input);
409
410 if (!bdata->timer_debounce) {
411 input_event(input, EV_KEY, button->code, 0);
412 input_sync(input);
413 goto out;
414 }
415
416 bdata->key_pressed = true;
417 }
418
419 if (bdata->timer_debounce)
420 mod_timer(&bdata->timer,
421 jiffies + msecs_to_jiffies(bdata->timer_debounce));
422out:
423 spin_unlock_irqrestore(&bdata->lock, flags);
424 return IRQ_HANDLED;
425}
426
427static int gpio_keys_setup_key(struct platform_device *pdev,
428 struct input_dev *input,
429 struct gpio_button_data *bdata,
430 const struct gpio_keys_button *button)
431{
432 const char *desc = button->desc ? button->desc : "gpio_keys";
433 struct device *dev = &pdev->dev;
434 irq_handler_t isr;
435 unsigned long irqflags;
436 int irq, error;
437
438 bdata->input = input;
439 bdata->button = button;
440 spin_lock_init(&bdata->lock);
441
442 if (gpio_is_valid(button->gpio)) {
443
444 error = gpio_request_one(button->gpio, GPIOF_IN, desc);
445 if (error < 0) {
446 dev_err(dev, "Failed to request GPIO %d, error %d\n",
447 button->gpio, error);
448 return error;
449 }
450
451 if (button->debounce_interval) {
452 error = gpio_set_debounce(button->gpio,
453 button->debounce_interval * 1000);
454 /* use timer if gpiolib doesn't provide debounce */
455 if (error < 0)
456 bdata->timer_debounce =
457 button->debounce_interval;
458 }
459
460 irq = gpio_to_irq(button->gpio);
461 if (irq < 0) {
462 error = irq;
463 dev_err(dev,
464 "Unable to get irq number for GPIO %d, error %d\n",
465 button->gpio, error);
466 goto fail;
467 }
468 bdata->irq = irq;
469
470 INIT_WORK(&bdata->work, gpio_keys_gpio_work_func);
471 setup_timer(&bdata->timer,
472 gpio_keys_gpio_timer, (unsigned long)bdata);
473
474 isr = gpio_keys_gpio_isr;
475 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
476
477 } else {
478 if (!button->irq) {
479 dev_err(dev, "No IRQ specified\n");
480 return -EINVAL;
481 }
482 bdata->irq = button->irq;
483
484 if (button->type && button->type != EV_KEY) {
485 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
486 return -EINVAL;
487 }
488
489 bdata->timer_debounce = button->debounce_interval;
490 setup_timer(&bdata->timer,
491 gpio_keys_irq_timer, (unsigned long)bdata);
492
493 isr = gpio_keys_irq_isr;
494 irqflags = 0;
495 }
496
497 input_set_capability(input, button->type ?: EV_KEY, button->code);
498
499 /*
500 * If platform has specified that the button can be disabled,
501 * we don't want it to share the interrupt line.
502 */
503 if (!button->can_disable)
504 irqflags |= IRQF_SHARED;
505
506 error = request_any_context_irq(bdata->irq, isr, irqflags, desc, bdata);
507 if (error < 0) {
508 dev_err(dev, "Unable to claim irq %d; error %d\n",
509 bdata->irq, error);
510 goto fail;
511 }
512
513 return 0;
514
515fail:
516 if (gpio_is_valid(button->gpio))
517 gpio_free(button->gpio);
518
519 return error;
520}
521
522static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
523{
524 struct input_dev *input = ddata->input;
525 int i;
526
527 for (i = 0; i < ddata->pdata->nbuttons; i++) {
528 struct gpio_button_data *bdata = &ddata->data[i];
529 if (gpio_is_valid(bdata->button->gpio))
530 gpio_keys_gpio_report_event(bdata);
531 }
532 input_sync(input);
533}
534
535static int gpio_keys_open(struct input_dev *input)
536{
537 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
538 const struct gpio_keys_platform_data *pdata = ddata->pdata;
539 int error;
540
541 if (pdata->enable) {
542 error = pdata->enable(input->dev.parent);
543 if (error)
544 return error;
545 }
546
547 /* Report current state of buttons that are connected to GPIOs */
548 gpio_keys_report_state(ddata);
549
550 return 0;
551}
552
553static void gpio_keys_close(struct input_dev *input)
554{
555 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
556 const struct gpio_keys_platform_data *pdata = ddata->pdata;
557
558 if (pdata->disable)
559 pdata->disable(input->dev.parent);
560}
561
562/*
563 * Handlers for alternative sources of platform_data
564 */
565
566#ifdef CONFIG_OF
567/*
568 * Translate OpenFirmware node properties into platform_data
569 */
570static struct gpio_keys_platform_data *
571gpio_keys_get_devtree_pdata(struct device *dev)
572{
573 struct device_node *node, *pp;
574 struct gpio_keys_platform_data *pdata;
575 struct gpio_keys_button *button;
576 int error;
577 int nbuttons;
578 int i;
579
580 node = dev->of_node;
581 if (!node) {
582 error = -ENODEV;
583 goto err_out;
584 }
585
586 nbuttons = of_get_child_count(node);
587 if (nbuttons == 0) {
588 error = -ENODEV;
589 goto err_out;
590 }
591
592 pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
593 GFP_KERNEL);
594 if (!pdata) {
595 error = -ENOMEM;
596 goto err_out;
597 }
598
599 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
600 pdata->nbuttons = nbuttons;
601
602 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
603
604 i = 0;
605 for_each_child_of_node(node, pp) {
606 int gpio;
607 enum of_gpio_flags flags;
608
609 if (!of_find_property(pp, "gpios", NULL)) {
610 pdata->nbuttons--;
611 dev_warn(dev, "Found button without gpios\n");
612 continue;
613 }
614
615 gpio = of_get_gpio_flags(pp, 0, &flags);
616 if (gpio < 0) {
617 error = gpio;
618 if (error != -EPROBE_DEFER)
619 dev_err(dev,
620 "Failed to get gpio flags, error: %d\n",
621 error);
622 goto err_free_pdata;
623 }
624
625 button = &pdata->buttons[i++];
626
627 button->gpio = gpio;
628 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
629
630 if (of_property_read_u32(pp, "linux,code", &button->code)) {
631 dev_err(dev, "Button without keycode: 0x%x\n",
632 button->gpio);
633 error = -EINVAL;
634 goto err_free_pdata;
635 }
636
637 button->desc = of_get_property(pp, "label", NULL);
638
639 if (of_property_read_u32(pp, "linux,input-type", &button->type))
640 button->type = EV_KEY;
641
642 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
643
644 if (of_property_read_u32(pp, "debounce-interval",
645 &button->debounce_interval))
646 button->debounce_interval = 5;
647 }
648
649 if (pdata->nbuttons == 0) {
650 error = -EINVAL;
651 goto err_free_pdata;
652 }
653
654 return pdata;
655
656err_free_pdata:
657 kfree(pdata);
658err_out:
659 return ERR_PTR(error);
660}
661
662static struct of_device_id gpio_keys_of_match[] = {
663 { .compatible = "gpio-keys", },
664 { },
665};
666MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
667
668#else
669
670static inline struct gpio_keys_platform_data *
671gpio_keys_get_devtree_pdata(struct device *dev)
672{
673 return ERR_PTR(-ENODEV);
674}
675
676#endif
677
678static void gpio_remove_key(struct gpio_button_data *bdata)
679{
680 free_irq(bdata->irq, bdata);
681 if (bdata->timer_debounce)
682 del_timer_sync(&bdata->timer);
683 cancel_work_sync(&bdata->work);
684 if (gpio_is_valid(bdata->button->gpio))
685 gpio_free(bdata->button->gpio);
686}
687
688static int gpio_keys_probe(struct platform_device *pdev)
689{
690 struct device *dev = &pdev->dev;
691 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
692 struct gpio_keys_drvdata *ddata;
693 struct input_dev *input;
694 int i, error;
695 int wakeup = 0;
696
697 if (!pdata) {
698 pdata = gpio_keys_get_devtree_pdata(dev);
699 if (IS_ERR(pdata))
700 return PTR_ERR(pdata);
701 }
702
703 ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
704 pdata->nbuttons * sizeof(struct gpio_button_data),
705 GFP_KERNEL);
706 input = input_allocate_device();
707 if (!ddata || !input) {
708 dev_err(dev, "failed to allocate state\n");
709 error = -ENOMEM;
710 goto fail1;
711 }
712
713 ddata->pdata = pdata;
714 ddata->input = input;
715 mutex_init(&ddata->disable_lock);
716
717 platform_set_drvdata(pdev, ddata);
718 input_set_drvdata(input, ddata);
719
720 input->name = pdata->name ? : pdev->name;
721 input->phys = "gpio-keys/input0";
722 input->dev.parent = &pdev->dev;
723 input->open = gpio_keys_open;
724 input->close = gpio_keys_close;
725
726 input->id.bustype = BUS_HOST;
727 input->id.vendor = 0x0001;
728 input->id.product = 0x0001;
729 input->id.version = 0x0100;
730
731 /* Enable auto repeat feature of Linux input subsystem */
732 if (pdata->rep)
733 __set_bit(EV_REP, input->evbit);
734
735 for (i = 0; i < pdata->nbuttons; i++) {
736 const struct gpio_keys_button *button = &pdata->buttons[i];
737 struct gpio_button_data *bdata = &ddata->data[i];
738
739 error = gpio_keys_setup_key(pdev, input, bdata, button);
740 if (error)
741 goto fail2;
742
743 if (button->wakeup)
744 wakeup = 1;
745 }
746
747 error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
748 if (error) {
749 dev_err(dev, "Unable to export keys/switches, error: %d\n",
750 error);
751 goto fail2;
752 }
753
754 error = input_register_device(input);
755 if (error) {
756 dev_err(dev, "Unable to register input device, error: %d\n",
757 error);
758 goto fail3;
759 }
760
761 device_init_wakeup(&pdev->dev, wakeup);
762
763 return 0;
764
765 fail3:
766 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
767 fail2:
768 while (--i >= 0)
769 gpio_remove_key(&ddata->data[i]);
770
771 fail1:
772 input_free_device(input);
773 kfree(ddata);
774 /* If we have no platform data, we allocated pdata dynamically. */
775 if (!dev_get_platdata(&pdev->dev))
776 kfree(pdata);
777
778 return error;
779}
780
781static int gpio_keys_remove(struct platform_device *pdev)
782{
783 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
784 struct input_dev *input = ddata->input;
785 int i;
786
787 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
788
789 device_init_wakeup(&pdev->dev, 0);
790
791 for (i = 0; i < ddata->pdata->nbuttons; i++)
792 gpio_remove_key(&ddata->data[i]);
793
794 input_unregister_device(input);
795
796 /* If we have no platform data, we allocated pdata dynamically. */
797 if (!dev_get_platdata(&pdev->dev))
798 kfree(ddata->pdata);
799
800 kfree(ddata);
801
802 return 0;
803}
804
805#ifdef CONFIG_PM_SLEEP
806static int gpio_keys_suspend(struct device *dev)
807{
808 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
809 struct input_dev *input = ddata->input;
810 int i;
811
812 if (device_may_wakeup(dev)) {
813 for (i = 0; i < ddata->pdata->nbuttons; i++) {
814 struct gpio_button_data *bdata = &ddata->data[i];
815 if (bdata->button->wakeup)
816 enable_irq_wake(bdata->irq);
817 }
818 } else {
819 mutex_lock(&input->mutex);
820 if (input->users)
821 gpio_keys_close(input);
822 mutex_unlock(&input->mutex);
823 }
824
825 return 0;
826}
827
828static int gpio_keys_resume(struct device *dev)
829{
830 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
831 struct input_dev *input = ddata->input;
832 int error = 0;
833 int i;
834
835 if (device_may_wakeup(dev)) {
836 for (i = 0; i < ddata->pdata->nbuttons; i++) {
837 struct gpio_button_data *bdata = &ddata->data[i];
838 if (bdata->button->wakeup)
839 disable_irq_wake(bdata->irq);
840 }
841 } else {
842 mutex_lock(&input->mutex);
843 if (input->users)
844 error = gpio_keys_open(input);
845 mutex_unlock(&input->mutex);
846 }
847
848 if (error)
849 return error;
850
851 gpio_keys_report_state(ddata);
852 return 0;
853}
854#endif
855
856static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
857
858static struct platform_driver gpio_keys_device_driver = {
859 .probe = gpio_keys_probe,
860 .remove = gpio_keys_remove,
861 .driver = {
862 .name = "gpio-keys",
863 .owner = THIS_MODULE,
864 .pm = &gpio_keys_pm_ops,
865 .of_match_table = of_match_ptr(gpio_keys_of_match),
866 }
867};
868
869static int __init gpio_keys_init(void)
870{
871 return platform_driver_register(&gpio_keys_device_driver);
872}
873
874static void __exit gpio_keys_exit(void)
875{
876 platform_driver_unregister(&gpio_keys_device_driver);
877}
878
879late_initcall(gpio_keys_init);
880module_exit(gpio_keys_exit);
881
882MODULE_LICENSE("GPL");
883MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
884MODULE_DESCRIPTION("Keyboard driver for GPIOs");
885MODULE_ALIAS("platform:gpio-keys");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for keys on GPIO lines capable of generating interrupts.
4 *
5 * Copyright 2005 Phil Blundell
6 * Copyright 2010, 2011 David Jander <david@protonic.nl>
7 */
8
9#include <linux/module.h>
10
11#include <linux/hrtimer.h>
12#include <linux/init.h>
13#include <linux/fs.h>
14#include <linux/interrupt.h>
15#include <linux/irq.h>
16#include <linux/sched.h>
17#include <linux/pm.h>
18#include <linux/slab.h>
19#include <linux/sysctl.h>
20#include <linux/proc_fs.h>
21#include <linux/delay.h>
22#include <linux/platform_device.h>
23#include <linux/input.h>
24#include <linux/gpio_keys.h>
25#include <linux/workqueue.h>
26#include <linux/gpio.h>
27#include <linux/gpio/consumer.h>
28#include <linux/of.h>
29#include <linux/of_irq.h>
30#include <linux/spinlock.h>
31#include <dt-bindings/input/gpio-keys.h>
32
33struct gpio_button_data {
34 const struct gpio_keys_button *button;
35 struct input_dev *input;
36 struct gpio_desc *gpiod;
37
38 unsigned short *code;
39
40 struct hrtimer release_timer;
41 unsigned int release_delay; /* in msecs, for IRQ-only buttons */
42
43 struct delayed_work work;
44 struct hrtimer debounce_timer;
45 unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
46
47 unsigned int irq;
48 unsigned int wakeirq;
49 unsigned int wakeup_trigger_type;
50
51 spinlock_t lock;
52 bool disabled;
53 bool key_pressed;
54 bool suspended;
55 bool debounce_use_hrtimer;
56};
57
58struct gpio_keys_drvdata {
59 const struct gpio_keys_platform_data *pdata;
60 struct input_dev *input;
61 struct mutex disable_lock;
62 unsigned short *keymap;
63 struct gpio_button_data data[];
64};
65
66/*
67 * SYSFS interface for enabling/disabling keys and switches:
68 *
69 * There are 4 attributes under /sys/devices/platform/gpio-keys/
70 * keys [ro] - bitmap of keys (EV_KEY) which can be
71 * disabled
72 * switches [ro] - bitmap of switches (EV_SW) which can be
73 * disabled
74 * disabled_keys [rw] - bitmap of keys currently disabled
75 * disabled_switches [rw] - bitmap of switches currently disabled
76 *
77 * Userland can change these values and hence disable event generation
78 * for each key (or switch). Disabling a key means its interrupt line
79 * is disabled.
80 *
81 * For example, if we have following switches set up as gpio-keys:
82 * SW_DOCK = 5
83 * SW_CAMERA_LENS_COVER = 9
84 * SW_KEYPAD_SLIDE = 10
85 * SW_FRONT_PROXIMITY = 11
86 * This is read from switches:
87 * 11-9,5
88 * Next we want to disable proximity (11) and dock (5), we write:
89 * 11,5
90 * to file disabled_switches. Now proximity and dock IRQs are disabled.
91 * This can be verified by reading the file disabled_switches:
92 * 11,5
93 * If we now want to enable proximity (11) switch we write:
94 * 5
95 * to disabled_switches.
96 *
97 * We can disable only those keys which don't allow sharing the irq.
98 */
99
100/**
101 * get_n_events_by_type() - returns maximum number of events per @type
102 * @type: type of button (%EV_KEY, %EV_SW)
103 *
104 * Return value of this function can be used to allocate bitmap
105 * large enough to hold all bits for given type.
106 */
107static int get_n_events_by_type(int type)
108{
109 BUG_ON(type != EV_SW && type != EV_KEY);
110
111 return (type == EV_KEY) ? KEY_CNT : SW_CNT;
112}
113
114/**
115 * get_bm_events_by_type() - returns bitmap of supported events per @type
116 * @dev: input device from which bitmap is retrieved
117 * @type: type of button (%EV_KEY, %EV_SW)
118 *
119 * Return value of this function can be used to allocate bitmap
120 * large enough to hold all bits for given type.
121 */
122static const unsigned long *get_bm_events_by_type(struct input_dev *dev,
123 int type)
124{
125 BUG_ON(type != EV_SW && type != EV_KEY);
126
127 return (type == EV_KEY) ? dev->keybit : dev->swbit;
128}
129
130static void gpio_keys_quiesce_key(void *data)
131{
132 struct gpio_button_data *bdata = data;
133
134 if (!bdata->gpiod)
135 hrtimer_cancel(&bdata->release_timer);
136 else if (bdata->debounce_use_hrtimer)
137 hrtimer_cancel(&bdata->debounce_timer);
138 else
139 cancel_delayed_work_sync(&bdata->work);
140}
141
142/**
143 * gpio_keys_disable_button() - disables given GPIO button
144 * @bdata: button data for button to be disabled
145 *
146 * Disables button pointed by @bdata. This is done by masking
147 * IRQ line. After this function is called, button won't generate
148 * input events anymore. Note that one can only disable buttons
149 * that don't share IRQs.
150 *
151 * Make sure that @bdata->disable_lock is locked when entering
152 * this function to avoid races when concurrent threads are
153 * disabling buttons at the same time.
154 */
155static void gpio_keys_disable_button(struct gpio_button_data *bdata)
156{
157 if (!bdata->disabled) {
158 /*
159 * Disable IRQ and associated timer/work structure.
160 */
161 disable_irq(bdata->irq);
162 gpio_keys_quiesce_key(bdata);
163 bdata->disabled = true;
164 }
165}
166
167/**
168 * gpio_keys_enable_button() - enables given GPIO button
169 * @bdata: button data for button to be disabled
170 *
171 * Enables given button pointed by @bdata.
172 *
173 * Make sure that @bdata->disable_lock is locked when entering
174 * this function to avoid races with concurrent threads trying
175 * to enable the same button at the same time.
176 */
177static void gpio_keys_enable_button(struct gpio_button_data *bdata)
178{
179 if (bdata->disabled) {
180 enable_irq(bdata->irq);
181 bdata->disabled = false;
182 }
183}
184
185/**
186 * gpio_keys_attr_show_helper() - fill in stringified bitmap of buttons
187 * @ddata: pointer to drvdata
188 * @buf: buffer where stringified bitmap is written
189 * @type: button type (%EV_KEY, %EV_SW)
190 * @only_disabled: does caller want only those buttons that are
191 * currently disabled or all buttons that can be
192 * disabled
193 *
194 * This function writes buttons that can be disabled to @buf. If
195 * @only_disabled is true, then @buf contains only those buttons
196 * that are currently disabled. Returns 0 on success or negative
197 * errno on failure.
198 */
199static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
200 char *buf, unsigned int type,
201 bool only_disabled)
202{
203 int n_events = get_n_events_by_type(type);
204 unsigned long *bits;
205 ssize_t ret;
206 int i;
207
208 bits = bitmap_zalloc(n_events, GFP_KERNEL);
209 if (!bits)
210 return -ENOMEM;
211
212 for (i = 0; i < ddata->pdata->nbuttons; i++) {
213 struct gpio_button_data *bdata = &ddata->data[i];
214
215 if (bdata->button->type != type)
216 continue;
217
218 if (only_disabled && !bdata->disabled)
219 continue;
220
221 __set_bit(*bdata->code, bits);
222 }
223
224 ret = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", n_events, bits);
225 buf[ret++] = '\n';
226 buf[ret] = '\0';
227
228 bitmap_free(bits);
229
230 return ret;
231}
232
233/**
234 * gpio_keys_attr_store_helper() - enable/disable buttons based on given bitmap
235 * @ddata: pointer to drvdata
236 * @buf: buffer from userspace that contains stringified bitmap
237 * @type: button type (%EV_KEY, %EV_SW)
238 *
239 * This function parses stringified bitmap from @buf and disables/enables
240 * GPIO buttons accordingly. Returns 0 on success and negative error
241 * on failure.
242 */
243static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
244 const char *buf, unsigned int type)
245{
246 int n_events = get_n_events_by_type(type);
247 const unsigned long *bitmap = get_bm_events_by_type(ddata->input, type);
248 ssize_t error;
249 int i;
250
251 unsigned long *bits __free(bitmap) = bitmap_alloc(n_events, GFP_KERNEL);
252 if (!bits)
253 return -ENOMEM;
254
255 error = bitmap_parselist(buf, bits, n_events);
256 if (error)
257 return error;
258
259 /* First validate */
260 if (!bitmap_subset(bits, bitmap, n_events))
261 return -EINVAL;
262
263 for (i = 0; i < ddata->pdata->nbuttons; i++) {
264 struct gpio_button_data *bdata = &ddata->data[i];
265
266 if (bdata->button->type != type)
267 continue;
268
269 if (test_bit(*bdata->code, bits) &&
270 !bdata->button->can_disable) {
271 return -EINVAL;
272 }
273 }
274
275 guard(mutex)(&ddata->disable_lock);
276
277 for (i = 0; i < ddata->pdata->nbuttons; i++) {
278 struct gpio_button_data *bdata = &ddata->data[i];
279
280 if (bdata->button->type != type)
281 continue;
282
283 if (test_bit(*bdata->code, bits))
284 gpio_keys_disable_button(bdata);
285 else
286 gpio_keys_enable_button(bdata);
287 }
288
289 return 0;
290}
291
292#define ATTR_SHOW_FN(name, type, only_disabled) \
293static ssize_t gpio_keys_show_##name(struct device *dev, \
294 struct device_attribute *attr, \
295 char *buf) \
296{ \
297 struct platform_device *pdev = to_platform_device(dev); \
298 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
299 \
300 return gpio_keys_attr_show_helper(ddata, buf, \
301 type, only_disabled); \
302}
303
304ATTR_SHOW_FN(keys, EV_KEY, false);
305ATTR_SHOW_FN(switches, EV_SW, false);
306ATTR_SHOW_FN(disabled_keys, EV_KEY, true);
307ATTR_SHOW_FN(disabled_switches, EV_SW, true);
308
309/*
310 * ATTRIBUTES:
311 *
312 * /sys/devices/platform/gpio-keys/keys [ro]
313 * /sys/devices/platform/gpio-keys/switches [ro]
314 */
315static DEVICE_ATTR(keys, S_IRUGO, gpio_keys_show_keys, NULL);
316static DEVICE_ATTR(switches, S_IRUGO, gpio_keys_show_switches, NULL);
317
318#define ATTR_STORE_FN(name, type) \
319static ssize_t gpio_keys_store_##name(struct device *dev, \
320 struct device_attribute *attr, \
321 const char *buf, \
322 size_t count) \
323{ \
324 struct platform_device *pdev = to_platform_device(dev); \
325 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); \
326 ssize_t error; \
327 \
328 error = gpio_keys_attr_store_helper(ddata, buf, type); \
329 if (error) \
330 return error; \
331 \
332 return count; \
333}
334
335ATTR_STORE_FN(disabled_keys, EV_KEY);
336ATTR_STORE_FN(disabled_switches, EV_SW);
337
338/*
339 * ATTRIBUTES:
340 *
341 * /sys/devices/platform/gpio-keys/disabled_keys [rw]
342 * /sys/devices/platform/gpio-keys/disables_switches [rw]
343 */
344static DEVICE_ATTR(disabled_keys, S_IWUSR | S_IRUGO,
345 gpio_keys_show_disabled_keys,
346 gpio_keys_store_disabled_keys);
347static DEVICE_ATTR(disabled_switches, S_IWUSR | S_IRUGO,
348 gpio_keys_show_disabled_switches,
349 gpio_keys_store_disabled_switches);
350
351static struct attribute *gpio_keys_attrs[] = {
352 &dev_attr_keys.attr,
353 &dev_attr_switches.attr,
354 &dev_attr_disabled_keys.attr,
355 &dev_attr_disabled_switches.attr,
356 NULL,
357};
358ATTRIBUTE_GROUPS(gpio_keys);
359
360static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata)
361{
362 const struct gpio_keys_button *button = bdata->button;
363 struct input_dev *input = bdata->input;
364 unsigned int type = button->type ?: EV_KEY;
365 int state;
366
367 state = bdata->debounce_use_hrtimer ?
368 gpiod_get_value(bdata->gpiod) :
369 gpiod_get_value_cansleep(bdata->gpiod);
370 if (state < 0) {
371 dev_err(input->dev.parent,
372 "failed to get gpio state: %d\n", state);
373 return;
374 }
375
376 if (type == EV_ABS) {
377 if (state)
378 input_event(input, type, button->code, button->value);
379 } else {
380 input_event(input, type, *bdata->code, state);
381 }
382}
383
384static void gpio_keys_debounce_event(struct gpio_button_data *bdata)
385{
386 gpio_keys_gpio_report_event(bdata);
387 input_sync(bdata->input);
388
389 if (bdata->button->wakeup)
390 pm_relax(bdata->input->dev.parent);
391}
392
393static void gpio_keys_gpio_work_func(struct work_struct *work)
394{
395 struct gpio_button_data *bdata =
396 container_of(work, struct gpio_button_data, work.work);
397
398 gpio_keys_debounce_event(bdata);
399}
400
401static enum hrtimer_restart gpio_keys_debounce_timer(struct hrtimer *t)
402{
403 struct gpio_button_data *bdata =
404 container_of(t, struct gpio_button_data, debounce_timer);
405
406 gpio_keys_debounce_event(bdata);
407
408 return HRTIMER_NORESTART;
409}
410
411static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
412{
413 struct gpio_button_data *bdata = dev_id;
414
415 BUG_ON(irq != bdata->irq);
416
417 if (bdata->button->wakeup) {
418 const struct gpio_keys_button *button = bdata->button;
419
420 pm_stay_awake(bdata->input->dev.parent);
421 if (bdata->suspended &&
422 (button->type == 0 || button->type == EV_KEY)) {
423 /*
424 * Simulate wakeup key press in case the key has
425 * already released by the time we got interrupt
426 * handler to run.
427 */
428 input_report_key(bdata->input, button->code, 1);
429 }
430 }
431
432 if (bdata->debounce_use_hrtimer) {
433 hrtimer_start(&bdata->debounce_timer,
434 ms_to_ktime(bdata->software_debounce),
435 HRTIMER_MODE_REL);
436 } else {
437 mod_delayed_work(system_wq,
438 &bdata->work,
439 msecs_to_jiffies(bdata->software_debounce));
440 }
441
442 return IRQ_HANDLED;
443}
444
445static enum hrtimer_restart gpio_keys_irq_timer(struct hrtimer *t)
446{
447 struct gpio_button_data *bdata = container_of(t,
448 struct gpio_button_data,
449 release_timer);
450 struct input_dev *input = bdata->input;
451
452 if (bdata->key_pressed) {
453 input_report_key(input, *bdata->code, 0);
454 input_sync(input);
455 bdata->key_pressed = false;
456 }
457
458 return HRTIMER_NORESTART;
459}
460
461static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
462{
463 struct gpio_button_data *bdata = dev_id;
464 struct input_dev *input = bdata->input;
465
466 BUG_ON(irq != bdata->irq);
467
468 guard(spinlock_irqsave)(&bdata->lock);
469
470 if (!bdata->key_pressed) {
471 if (bdata->button->wakeup)
472 pm_wakeup_event(bdata->input->dev.parent, 0);
473
474 input_report_key(input, *bdata->code, 1);
475 input_sync(input);
476
477 if (!bdata->release_delay) {
478 input_report_key(input, *bdata->code, 0);
479 input_sync(input);
480 goto out;
481 }
482
483 bdata->key_pressed = true;
484 }
485
486 if (bdata->release_delay)
487 hrtimer_start(&bdata->release_timer,
488 ms_to_ktime(bdata->release_delay),
489 HRTIMER_MODE_REL_HARD);
490out:
491 return IRQ_HANDLED;
492}
493
494static int gpio_keys_setup_key(struct platform_device *pdev,
495 struct input_dev *input,
496 struct gpio_keys_drvdata *ddata,
497 const struct gpio_keys_button *button,
498 int idx,
499 struct fwnode_handle *child)
500{
501 const char *desc = button->desc ? button->desc : "gpio_keys";
502 struct device *dev = &pdev->dev;
503 struct gpio_button_data *bdata = &ddata->data[idx];
504 irq_handler_t isr;
505 unsigned long irqflags;
506 const char *wakedesc;
507 int irq;
508 int error;
509
510 bdata->input = input;
511 bdata->button = button;
512 spin_lock_init(&bdata->lock);
513
514 if (child) {
515 bdata->gpiod = devm_fwnode_gpiod_get(dev, child,
516 NULL, GPIOD_IN, desc);
517 if (IS_ERR(bdata->gpiod)) {
518 error = PTR_ERR(bdata->gpiod);
519 if (error != -ENOENT)
520 return dev_err_probe(dev, error,
521 "failed to get gpio\n");
522
523 /*
524 * GPIO is optional, we may be dealing with
525 * purely interrupt-driven setup.
526 */
527 bdata->gpiod = NULL;
528 }
529 } else if (gpio_is_valid(button->gpio)) {
530 /*
531 * Legacy GPIO number, so request the GPIO here and
532 * convert it to descriptor.
533 */
534 error = devm_gpio_request_one(dev, button->gpio, GPIOF_IN, desc);
535 if (error < 0) {
536 dev_err(dev, "Failed to request GPIO %d, error %d\n",
537 button->gpio, error);
538 return error;
539 }
540
541 bdata->gpiod = gpio_to_desc(button->gpio);
542 if (!bdata->gpiod)
543 return -EINVAL;
544
545 if (button->active_low ^ gpiod_is_active_low(bdata->gpiod))
546 gpiod_toggle_active_low(bdata->gpiod);
547 }
548
549 if (bdata->gpiod) {
550 bool active_low = gpiod_is_active_low(bdata->gpiod);
551
552 if (button->debounce_interval) {
553 error = gpiod_set_debounce(bdata->gpiod,
554 button->debounce_interval * 1000);
555 /* use timer if gpiolib doesn't provide debounce */
556 if (error < 0)
557 bdata->software_debounce =
558 button->debounce_interval;
559
560 /*
561 * If reading the GPIO won't sleep, we can use a
562 * hrtimer instead of a standard timer for the software
563 * debounce, to reduce the latency as much as possible.
564 */
565 bdata->debounce_use_hrtimer =
566 !gpiod_cansleep(bdata->gpiod);
567 }
568
569 /*
570 * If an interrupt was specified, use it instead of the gpio
571 * interrupt and use the gpio for reading the state. A separate
572 * interrupt may be used as the main button interrupt for
573 * runtime PM to detect events also in deeper idle states. If a
574 * dedicated wakeirq is used for system suspend only, see below
575 * for bdata->wakeirq setup.
576 */
577 if (button->irq) {
578 bdata->irq = button->irq;
579 } else {
580 irq = gpiod_to_irq(bdata->gpiod);
581 if (irq < 0) {
582 error = irq;
583 dev_err_probe(dev, error,
584 "Unable to get irq number for GPIO %d\n",
585 button->gpio);
586 return error;
587 }
588 bdata->irq = irq;
589 }
590
591 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
592
593 hrtimer_init(&bdata->debounce_timer,
594 CLOCK_REALTIME, HRTIMER_MODE_REL);
595 bdata->debounce_timer.function = gpio_keys_debounce_timer;
596
597 isr = gpio_keys_gpio_isr;
598 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
599
600 switch (button->wakeup_event_action) {
601 case EV_ACT_ASSERTED:
602 bdata->wakeup_trigger_type = active_low ?
603 IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
604 break;
605 case EV_ACT_DEASSERTED:
606 bdata->wakeup_trigger_type = active_low ?
607 IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
608 break;
609 case EV_ACT_ANY:
610 default:
611 /*
612 * For other cases, we are OK letting suspend/resume
613 * not reconfigure the trigger type.
614 */
615 break;
616 }
617 } else {
618 if (!button->irq) {
619 dev_err(dev, "Found button without gpio or irq\n");
620 return -EINVAL;
621 }
622
623 bdata->irq = button->irq;
624
625 if (button->type && button->type != EV_KEY) {
626 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
627 return -EINVAL;
628 }
629
630 bdata->release_delay = button->debounce_interval;
631 hrtimer_init(&bdata->release_timer,
632 CLOCK_REALTIME, HRTIMER_MODE_REL_HARD);
633 bdata->release_timer.function = gpio_keys_irq_timer;
634
635 isr = gpio_keys_irq_isr;
636 irqflags = 0;
637
638 /*
639 * For IRQ buttons, there is no interrupt for release.
640 * So we don't need to reconfigure the trigger type for wakeup.
641 */
642 }
643
644 bdata->code = &ddata->keymap[idx];
645 *bdata->code = button->code;
646 input_set_capability(input, button->type ?: EV_KEY, *bdata->code);
647
648 /*
649 * Install custom action to cancel release timer and
650 * workqueue item.
651 */
652 error = devm_add_action(dev, gpio_keys_quiesce_key, bdata);
653 if (error) {
654 dev_err(dev, "failed to register quiesce action, error: %d\n",
655 error);
656 return error;
657 }
658
659 /*
660 * If platform has specified that the button can be disabled,
661 * we don't want it to share the interrupt line.
662 */
663 if (!button->can_disable)
664 irqflags |= IRQF_SHARED;
665
666 error = devm_request_any_context_irq(dev, bdata->irq, isr, irqflags,
667 desc, bdata);
668 if (error < 0) {
669 dev_err(dev, "Unable to claim irq %d; error %d\n",
670 bdata->irq, error);
671 return error;
672 }
673
674 if (!button->wakeirq)
675 return 0;
676
677 /* Use :wakeup suffix like drivers/base/power/wakeirq.c does */
678 wakedesc = devm_kasprintf(dev, GFP_KERNEL, "%s:wakeup", desc);
679 if (!wakedesc)
680 return -ENOMEM;
681
682 bdata->wakeirq = button->wakeirq;
683 irqflags |= IRQF_NO_SUSPEND;
684
685 /*
686 * Wakeirq shares the handler with the main interrupt, it's only
687 * active during system suspend. See gpio_keys_button_enable_wakeup()
688 * and gpio_keys_button_disable_wakeup().
689 */
690 error = devm_request_any_context_irq(dev, bdata->wakeirq, isr,
691 irqflags, wakedesc, bdata);
692 if (error < 0) {
693 dev_err(dev, "Unable to claim wakeirq %d; error %d\n",
694 bdata->irq, error);
695 return error;
696 }
697
698 /*
699 * Disable wakeirq until suspend. IRQF_NO_AUTOEN won't work if
700 * IRQF_SHARED was set based on !button->can_disable.
701 */
702 disable_irq(bdata->wakeirq);
703
704 return 0;
705}
706
707static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
708{
709 struct input_dev *input = ddata->input;
710 int i;
711
712 for (i = 0; i < ddata->pdata->nbuttons; i++) {
713 struct gpio_button_data *bdata = &ddata->data[i];
714 if (bdata->gpiod)
715 gpio_keys_gpio_report_event(bdata);
716 }
717 input_sync(input);
718}
719
720static int gpio_keys_open(struct input_dev *input)
721{
722 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
723 const struct gpio_keys_platform_data *pdata = ddata->pdata;
724 int error;
725
726 if (pdata->enable) {
727 error = pdata->enable(input->dev.parent);
728 if (error)
729 return error;
730 }
731
732 /* Report current state of buttons that are connected to GPIOs */
733 gpio_keys_report_state(ddata);
734
735 return 0;
736}
737
738static void gpio_keys_close(struct input_dev *input)
739{
740 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
741 const struct gpio_keys_platform_data *pdata = ddata->pdata;
742
743 if (pdata->disable)
744 pdata->disable(input->dev.parent);
745}
746
747/*
748 * Handlers for alternative sources of platform_data
749 */
750
751/*
752 * Translate properties into platform_data
753 */
754static struct gpio_keys_platform_data *
755gpio_keys_get_devtree_pdata(struct device *dev)
756{
757 struct gpio_keys_platform_data *pdata;
758 struct gpio_keys_button *button;
759 int nbuttons, irq;
760
761 nbuttons = device_get_child_node_count(dev);
762 if (nbuttons == 0)
763 return ERR_PTR(-ENODEV);
764
765 pdata = devm_kzalloc(dev,
766 sizeof(*pdata) + nbuttons * sizeof(*button),
767 GFP_KERNEL);
768 if (!pdata)
769 return ERR_PTR(-ENOMEM);
770
771 button = (struct gpio_keys_button *)(pdata + 1);
772
773 pdata->buttons = button;
774 pdata->nbuttons = nbuttons;
775
776 pdata->rep = device_property_read_bool(dev, "autorepeat");
777
778 device_property_read_string(dev, "label", &pdata->name);
779
780 device_for_each_child_node_scoped(dev, child) {
781 if (is_of_node(child)) {
782 irq = of_irq_get_byname(to_of_node(child), "irq");
783 if (irq > 0)
784 button->irq = irq;
785
786 irq = of_irq_get_byname(to_of_node(child), "wakeup");
787 if (irq > 0)
788 button->wakeirq = irq;
789
790 if (!button->irq && !button->wakeirq)
791 button->irq =
792 irq_of_parse_and_map(to_of_node(child), 0);
793 }
794
795 if (fwnode_property_read_u32(child, "linux,code",
796 &button->code)) {
797 dev_err(dev, "Button without keycode\n");
798 return ERR_PTR(-EINVAL);
799 }
800
801 fwnode_property_read_string(child, "label", &button->desc);
802
803 if (fwnode_property_read_u32(child, "linux,input-type",
804 &button->type))
805 button->type = EV_KEY;
806
807 fwnode_property_read_u32(child, "linux,input-value",
808 (u32 *)&button->value);
809
810 button->wakeup =
811 fwnode_property_read_bool(child, "wakeup-source") ||
812 /* legacy name */
813 fwnode_property_read_bool(child, "gpio-key,wakeup");
814
815 fwnode_property_read_u32(child, "wakeup-event-action",
816 &button->wakeup_event_action);
817
818 button->can_disable =
819 fwnode_property_read_bool(child, "linux,can-disable");
820
821 if (fwnode_property_read_u32(child, "debounce-interval",
822 &button->debounce_interval))
823 button->debounce_interval = 5;
824
825 button++;
826 }
827
828 return pdata;
829}
830
831static const struct of_device_id gpio_keys_of_match[] = {
832 { .compatible = "gpio-keys", },
833 { },
834};
835MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
836
837static int gpio_keys_probe(struct platform_device *pdev)
838{
839 struct device *dev = &pdev->dev;
840 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
841 struct fwnode_handle *child = NULL;
842 struct gpio_keys_drvdata *ddata;
843 struct input_dev *input;
844 int i, error;
845 int wakeup = 0;
846
847 if (!pdata) {
848 pdata = gpio_keys_get_devtree_pdata(dev);
849 if (IS_ERR(pdata))
850 return PTR_ERR(pdata);
851 }
852
853 ddata = devm_kzalloc(dev, struct_size(ddata, data, pdata->nbuttons),
854 GFP_KERNEL);
855 if (!ddata) {
856 dev_err(dev, "failed to allocate state\n");
857 return -ENOMEM;
858 }
859
860 ddata->keymap = devm_kcalloc(dev,
861 pdata->nbuttons, sizeof(ddata->keymap[0]),
862 GFP_KERNEL);
863 if (!ddata->keymap)
864 return -ENOMEM;
865
866 input = devm_input_allocate_device(dev);
867 if (!input) {
868 dev_err(dev, "failed to allocate input device\n");
869 return -ENOMEM;
870 }
871
872 ddata->pdata = pdata;
873 ddata->input = input;
874 mutex_init(&ddata->disable_lock);
875
876 platform_set_drvdata(pdev, ddata);
877 input_set_drvdata(input, ddata);
878
879 input->name = pdata->name ? : pdev->name;
880 input->phys = "gpio-keys/input0";
881 input->dev.parent = dev;
882 input->open = gpio_keys_open;
883 input->close = gpio_keys_close;
884
885 input->id.bustype = BUS_HOST;
886 input->id.vendor = 0x0001;
887 input->id.product = 0x0001;
888 input->id.version = 0x0100;
889
890 input->keycode = ddata->keymap;
891 input->keycodesize = sizeof(ddata->keymap[0]);
892 input->keycodemax = pdata->nbuttons;
893
894 /* Enable auto repeat feature of Linux input subsystem */
895 if (pdata->rep)
896 __set_bit(EV_REP, input->evbit);
897
898 for (i = 0; i < pdata->nbuttons; i++) {
899 const struct gpio_keys_button *button = &pdata->buttons[i];
900
901 if (!dev_get_platdata(dev)) {
902 child = device_get_next_child_node(dev, child);
903 if (!child) {
904 dev_err(dev,
905 "missing child device node for entry %d\n",
906 i);
907 return -EINVAL;
908 }
909 }
910
911 error = gpio_keys_setup_key(pdev, input, ddata,
912 button, i, child);
913 if (error) {
914 fwnode_handle_put(child);
915 return error;
916 }
917
918 if (button->wakeup)
919 wakeup = 1;
920 }
921
922 fwnode_handle_put(child);
923
924 error = input_register_device(input);
925 if (error) {
926 dev_err(dev, "Unable to register input device, error: %d\n",
927 error);
928 return error;
929 }
930
931 device_init_wakeup(dev, wakeup);
932
933 return 0;
934}
935
936static int __maybe_unused
937gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
938{
939 int error;
940
941 error = enable_irq_wake(bdata->irq);
942 if (error) {
943 dev_err(bdata->input->dev.parent,
944 "failed to configure IRQ %d as wakeup source: %d\n",
945 bdata->irq, error);
946 return error;
947 }
948
949 if (bdata->wakeup_trigger_type) {
950 error = irq_set_irq_type(bdata->irq,
951 bdata->wakeup_trigger_type);
952 if (error) {
953 dev_err(bdata->input->dev.parent,
954 "failed to set wakeup trigger %08x for IRQ %d: %d\n",
955 bdata->wakeup_trigger_type, bdata->irq, error);
956 disable_irq_wake(bdata->irq);
957 return error;
958 }
959 }
960
961 if (bdata->wakeirq) {
962 enable_irq(bdata->wakeirq);
963 disable_irq(bdata->irq);
964 }
965
966 return 0;
967}
968
969static void __maybe_unused
970gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
971{
972 int error;
973
974 if (bdata->wakeirq) {
975 enable_irq(bdata->irq);
976 disable_irq(bdata->wakeirq);
977 }
978
979 /*
980 * The trigger type is always both edges for gpio-based keys and we do
981 * not support changing wakeup trigger for interrupt-based keys.
982 */
983 if (bdata->wakeup_trigger_type) {
984 error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
985 if (error)
986 dev_warn(bdata->input->dev.parent,
987 "failed to restore interrupt trigger for IRQ %d: %d\n",
988 bdata->irq, error);
989 }
990
991 error = disable_irq_wake(bdata->irq);
992 if (error)
993 dev_warn(bdata->input->dev.parent,
994 "failed to disable IRQ %d as wake source: %d\n",
995 bdata->irq, error);
996}
997
998static int __maybe_unused
999gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
1000{
1001 struct gpio_button_data *bdata;
1002 int error;
1003 int i;
1004
1005 for (i = 0; i < ddata->pdata->nbuttons; i++) {
1006 bdata = &ddata->data[i];
1007 if (bdata->button->wakeup) {
1008 error = gpio_keys_button_enable_wakeup(bdata);
1009 if (error)
1010 goto err_out;
1011 }
1012 bdata->suspended = true;
1013 }
1014
1015 return 0;
1016
1017err_out:
1018 while (i--) {
1019 bdata = &ddata->data[i];
1020 if (bdata->button->wakeup)
1021 gpio_keys_button_disable_wakeup(bdata);
1022 bdata->suspended = false;
1023 }
1024
1025 return error;
1026}
1027
1028static void __maybe_unused
1029gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
1030{
1031 struct gpio_button_data *bdata;
1032 int i;
1033
1034 for (i = 0; i < ddata->pdata->nbuttons; i++) {
1035 bdata = &ddata->data[i];
1036 bdata->suspended = false;
1037 if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
1038 gpio_keys_button_disable_wakeup(bdata);
1039 }
1040}
1041
1042static int gpio_keys_suspend(struct device *dev)
1043{
1044 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
1045 struct input_dev *input = ddata->input;
1046 int error;
1047
1048 if (device_may_wakeup(dev)) {
1049 error = gpio_keys_enable_wakeup(ddata);
1050 if (error)
1051 return error;
1052 } else {
1053 guard(mutex)(&input->mutex);
1054
1055 if (input_device_enabled(input))
1056 gpio_keys_close(input);
1057 }
1058
1059 return 0;
1060}
1061
1062static int gpio_keys_resume(struct device *dev)
1063{
1064 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
1065 struct input_dev *input = ddata->input;
1066 int error;
1067
1068 if (device_may_wakeup(dev)) {
1069 gpio_keys_disable_wakeup(ddata);
1070 } else {
1071 guard(mutex)(&input->mutex);
1072
1073 if (input_device_enabled(input)) {
1074 error = gpio_keys_open(input);
1075 if (error)
1076 return error;
1077 }
1078 }
1079
1080 gpio_keys_report_state(ddata);
1081 return 0;
1082}
1083
1084static DEFINE_SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
1085
1086static void gpio_keys_shutdown(struct platform_device *pdev)
1087{
1088 int ret;
1089
1090 ret = gpio_keys_suspend(&pdev->dev);
1091 if (ret)
1092 dev_err(&pdev->dev, "failed to shutdown\n");
1093}
1094
1095static struct platform_driver gpio_keys_device_driver = {
1096 .probe = gpio_keys_probe,
1097 .shutdown = gpio_keys_shutdown,
1098 .driver = {
1099 .name = "gpio-keys",
1100 .pm = pm_sleep_ptr(&gpio_keys_pm_ops),
1101 .of_match_table = gpio_keys_of_match,
1102 .dev_groups = gpio_keys_groups,
1103 }
1104};
1105
1106static int __init gpio_keys_init(void)
1107{
1108 return platform_driver_register(&gpio_keys_device_driver);
1109}
1110
1111static void __exit gpio_keys_exit(void)
1112{
1113 platform_driver_unregister(&gpio_keys_device_driver);
1114}
1115
1116late_initcall(gpio_keys_init);
1117module_exit(gpio_keys_exit);
1118
1119MODULE_LICENSE("GPL");
1120MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
1121MODULE_DESCRIPTION("Keyboard driver for GPIOs");
1122MODULE_ALIAS("platform:gpio-keys");