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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/*
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/of_irq.h>
33#include <linux/spinlock.h>
34
35struct gpio_button_data {
36 const struct gpio_keys_button *button;
37 struct input_dev *input;
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 (gpio_is_valid(bdata->button->gpio))
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 = gpio_get_value_cansleep(button->gpio);
362
363 if (state < 0) {
364 dev_err(input->dev.parent, "failed to get gpio state\n");
365 return;
366 }
367
368 state = (state ? 1 : 0) ^ button->active_low;
369 if (type == EV_ABS) {
370 if (state)
371 input_event(input, type, button->code, button->value);
372 } else {
373 input_event(input, type, button->code, !!state);
374 }
375 input_sync(input);
376}
377
378static void gpio_keys_gpio_work_func(struct work_struct *work)
379{
380 struct gpio_button_data *bdata =
381 container_of(work, struct gpio_button_data, work.work);
382
383 gpio_keys_gpio_report_event(bdata);
384
385 if (bdata->button->wakeup)
386 pm_relax(bdata->input->dev.parent);
387}
388
389static irqreturn_t gpio_keys_gpio_isr(int irq, void *dev_id)
390{
391 struct gpio_button_data *bdata = dev_id;
392
393 BUG_ON(irq != bdata->irq);
394
395 if (bdata->button->wakeup)
396 pm_stay_awake(bdata->input->dev.parent);
397
398 mod_delayed_work(system_wq,
399 &bdata->work,
400 msecs_to_jiffies(bdata->software_debounce));
401
402 return IRQ_HANDLED;
403}
404
405static void gpio_keys_irq_timer(unsigned long _data)
406{
407 struct gpio_button_data *bdata = (struct gpio_button_data *)_data;
408 struct input_dev *input = bdata->input;
409 unsigned long flags;
410
411 spin_lock_irqsave(&bdata->lock, flags);
412 if (bdata->key_pressed) {
413 input_event(input, EV_KEY, bdata->button->code, 0);
414 input_sync(input);
415 bdata->key_pressed = false;
416 }
417 spin_unlock_irqrestore(&bdata->lock, flags);
418}
419
420static irqreturn_t gpio_keys_irq_isr(int irq, void *dev_id)
421{
422 struct gpio_button_data *bdata = dev_id;
423 const struct gpio_keys_button *button = bdata->button;
424 struct input_dev *input = bdata->input;
425 unsigned long flags;
426
427 BUG_ON(irq != bdata->irq);
428
429 spin_lock_irqsave(&bdata->lock, flags);
430
431 if (!bdata->key_pressed) {
432 if (bdata->button->wakeup)
433 pm_wakeup_event(bdata->input->dev.parent, 0);
434
435 input_event(input, EV_KEY, button->code, 1);
436 input_sync(input);
437
438 if (!bdata->release_delay) {
439 input_event(input, EV_KEY, button->code, 0);
440 input_sync(input);
441 goto out;
442 }
443
444 bdata->key_pressed = true;
445 }
446
447 if (bdata->release_delay)
448 mod_timer(&bdata->release_timer,
449 jiffies + msecs_to_jiffies(bdata->release_delay));
450out:
451 spin_unlock_irqrestore(&bdata->lock, flags);
452 return IRQ_HANDLED;
453}
454
455static void gpio_keys_quiesce_key(void *data)
456{
457 struct gpio_button_data *bdata = data;
458
459 if (gpio_is_valid(bdata->button->gpio))
460 cancel_delayed_work_sync(&bdata->work);
461 else
462 del_timer_sync(&bdata->release_timer);
463}
464
465static int gpio_keys_setup_key(struct platform_device *pdev,
466 struct input_dev *input,
467 struct gpio_button_data *bdata,
468 const struct gpio_keys_button *button)
469{
470 const char *desc = button->desc ? button->desc : "gpio_keys";
471 struct device *dev = &pdev->dev;
472 irq_handler_t isr;
473 unsigned long irqflags;
474 int irq;
475 int error;
476
477 bdata->input = input;
478 bdata->button = button;
479 spin_lock_init(&bdata->lock);
480
481 if (gpio_is_valid(button->gpio)) {
482
483 error = devm_gpio_request_one(&pdev->dev, button->gpio,
484 GPIOF_IN, desc);
485 if (error < 0) {
486 dev_err(dev, "Failed to request GPIO %d, error %d\n",
487 button->gpio, error);
488 return error;
489 }
490
491 if (button->debounce_interval) {
492 error = gpio_set_debounce(button->gpio,
493 button->debounce_interval * 1000);
494 /* use timer if gpiolib doesn't provide debounce */
495 if (error < 0)
496 bdata->software_debounce =
497 button->debounce_interval;
498 }
499
500 if (button->irq) {
501 bdata->irq = button->irq;
502 } else {
503 irq = gpio_to_irq(button->gpio);
504 if (irq < 0) {
505 error = irq;
506 dev_err(dev,
507 "Unable to get irq number for GPIO %d, error %d\n",
508 button->gpio, error);
509 return error;
510 }
511 bdata->irq = irq;
512 }
513
514 INIT_DELAYED_WORK(&bdata->work, gpio_keys_gpio_work_func);
515
516 isr = gpio_keys_gpio_isr;
517 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
518
519 } else {
520 if (!button->irq) {
521 dev_err(dev, "No IRQ specified\n");
522 return -EINVAL;
523 }
524 bdata->irq = button->irq;
525
526 if (button->type && button->type != EV_KEY) {
527 dev_err(dev, "Only EV_KEY allowed for IRQ buttons.\n");
528 return -EINVAL;
529 }
530
531 bdata->release_delay = button->debounce_interval;
532 setup_timer(&bdata->release_timer,
533 gpio_keys_irq_timer, (unsigned long)bdata);
534
535 isr = gpio_keys_irq_isr;
536 irqflags = 0;
537 }
538
539 input_set_capability(input, button->type ?: EV_KEY, button->code);
540
541 /*
542 * Install custom action to cancel release timer and
543 * workqueue item.
544 */
545 error = devm_add_action(&pdev->dev, gpio_keys_quiesce_key, bdata);
546 if (error) {
547 dev_err(&pdev->dev,
548 "failed to register quiesce action, error: %d\n",
549 error);
550 return error;
551 }
552
553 /*
554 * If platform has specified that the button can be disabled,
555 * we don't want it to share the interrupt line.
556 */
557 if (!button->can_disable)
558 irqflags |= IRQF_SHARED;
559
560 error = devm_request_any_context_irq(&pdev->dev, bdata->irq,
561 isr, irqflags, desc, bdata);
562 if (error < 0) {
563 dev_err(dev, "Unable to claim irq %d; error %d\n",
564 bdata->irq, error);
565 return error;
566 }
567
568 return 0;
569}
570
571static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata)
572{
573 struct input_dev *input = ddata->input;
574 int i;
575
576 for (i = 0; i < ddata->pdata->nbuttons; i++) {
577 struct gpio_button_data *bdata = &ddata->data[i];
578 if (gpio_is_valid(bdata->button->gpio))
579 gpio_keys_gpio_report_event(bdata);
580 }
581 input_sync(input);
582}
583
584static int gpio_keys_open(struct input_dev *input)
585{
586 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
587 const struct gpio_keys_platform_data *pdata = ddata->pdata;
588 int error;
589
590 if (pdata->enable) {
591 error = pdata->enable(input->dev.parent);
592 if (error)
593 return error;
594 }
595
596 /* Report current state of buttons that are connected to GPIOs */
597 gpio_keys_report_state(ddata);
598
599 return 0;
600}
601
602static void gpio_keys_close(struct input_dev *input)
603{
604 struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
605 const struct gpio_keys_platform_data *pdata = ddata->pdata;
606
607 if (pdata->disable)
608 pdata->disable(input->dev.parent);
609}
610
611/*
612 * Handlers for alternative sources of platform_data
613 */
614
615#ifdef CONFIG_OF
616/*
617 * Translate OpenFirmware node properties into platform_data
618 */
619static struct gpio_keys_platform_data *
620gpio_keys_get_devtree_pdata(struct device *dev)
621{
622 struct device_node *node, *pp;
623 struct gpio_keys_platform_data *pdata;
624 struct gpio_keys_button *button;
625 int error;
626 int nbuttons;
627 int i;
628
629 node = dev->of_node;
630 if (!node)
631 return ERR_PTR(-ENODEV);
632
633 nbuttons = of_get_available_child_count(node);
634 if (nbuttons == 0)
635 return ERR_PTR(-ENODEV);
636
637 pdata = devm_kzalloc(dev,
638 sizeof(*pdata) + nbuttons * sizeof(*button),
639 GFP_KERNEL);
640 if (!pdata)
641 return ERR_PTR(-ENOMEM);
642
643 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
644 pdata->nbuttons = nbuttons;
645
646 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
647
648 of_property_read_string(node, "label", &pdata->name);
649
650 i = 0;
651 for_each_available_child_of_node(node, pp) {
652 enum of_gpio_flags flags;
653
654 button = &pdata->buttons[i++];
655
656 button->gpio = of_get_gpio_flags(pp, 0, &flags);
657 if (button->gpio < 0) {
658 error = button->gpio;
659 if (error != -ENOENT) {
660 if (error != -EPROBE_DEFER)
661 dev_err(dev,
662 "Failed to get gpio flags, error: %d\n",
663 error);
664 return ERR_PTR(error);
665 }
666 } else {
667 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
668 }
669
670 button->irq = irq_of_parse_and_map(pp, 0);
671
672 if (!gpio_is_valid(button->gpio) && !button->irq) {
673 dev_err(dev, "Found button without gpios or irqs\n");
674 return ERR_PTR(-EINVAL);
675 }
676
677 if (of_property_read_u32(pp, "linux,code", &button->code)) {
678 dev_err(dev, "Button without keycode: 0x%x\n",
679 button->gpio);
680 return ERR_PTR(-EINVAL);
681 }
682
683 button->desc = of_get_property(pp, "label", NULL);
684
685 if (of_property_read_u32(pp, "linux,input-type", &button->type))
686 button->type = EV_KEY;
687
688 button->wakeup = of_property_read_bool(pp, "wakeup-source") ||
689 /* legacy name */
690 of_property_read_bool(pp, "gpio-key,wakeup");
691
692 button->can_disable = !!of_get_property(pp, "linux,can-disable", NULL);
693
694 if (of_property_read_u32(pp, "debounce-interval",
695 &button->debounce_interval))
696 button->debounce_interval = 5;
697 }
698
699 if (pdata->nbuttons == 0)
700 return ERR_PTR(-EINVAL);
701
702 return pdata;
703}
704
705static const struct of_device_id gpio_keys_of_match[] = {
706 { .compatible = "gpio-keys", },
707 { },
708};
709MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
710
711#else
712
713static inline struct gpio_keys_platform_data *
714gpio_keys_get_devtree_pdata(struct device *dev)
715{
716 return ERR_PTR(-ENODEV);
717}
718
719#endif
720
721static int gpio_keys_probe(struct platform_device *pdev)
722{
723 struct device *dev = &pdev->dev;
724 const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
725 struct gpio_keys_drvdata *ddata;
726 struct input_dev *input;
727 size_t size;
728 int i, error;
729 int wakeup = 0;
730
731 if (!pdata) {
732 pdata = gpio_keys_get_devtree_pdata(dev);
733 if (IS_ERR(pdata))
734 return PTR_ERR(pdata);
735 }
736
737 size = sizeof(struct gpio_keys_drvdata) +
738 pdata->nbuttons * sizeof(struct gpio_button_data);
739 ddata = devm_kzalloc(dev, size, GFP_KERNEL);
740 if (!ddata) {
741 dev_err(dev, "failed to allocate state\n");
742 return -ENOMEM;
743 }
744
745 input = devm_input_allocate_device(dev);
746 if (!input) {
747 dev_err(dev, "failed to allocate input device\n");
748 return -ENOMEM;
749 }
750
751 ddata->pdata = pdata;
752 ddata->input = input;
753 mutex_init(&ddata->disable_lock);
754
755 platform_set_drvdata(pdev, ddata);
756 input_set_drvdata(input, ddata);
757
758 input->name = pdata->name ? : pdev->name;
759 input->phys = "gpio-keys/input0";
760 input->dev.parent = &pdev->dev;
761 input->open = gpio_keys_open;
762 input->close = gpio_keys_close;
763
764 input->id.bustype = BUS_HOST;
765 input->id.vendor = 0x0001;
766 input->id.product = 0x0001;
767 input->id.version = 0x0100;
768
769 /* Enable auto repeat feature of Linux input subsystem */
770 if (pdata->rep)
771 __set_bit(EV_REP, input->evbit);
772
773 for (i = 0; i < pdata->nbuttons; i++) {
774 const struct gpio_keys_button *button = &pdata->buttons[i];
775 struct gpio_button_data *bdata = &ddata->data[i];
776
777 error = gpio_keys_setup_key(pdev, input, bdata, button);
778 if (error)
779 return error;
780
781 if (button->wakeup)
782 wakeup = 1;
783 }
784
785 error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
786 if (error) {
787 dev_err(dev, "Unable to export keys/switches, error: %d\n",
788 error);
789 return error;
790 }
791
792 error = input_register_device(input);
793 if (error) {
794 dev_err(dev, "Unable to register input device, error: %d\n",
795 error);
796 goto err_remove_group;
797 }
798
799 device_init_wakeup(&pdev->dev, wakeup);
800
801 return 0;
802
803err_remove_group:
804 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
805 return error;
806}
807
808static int gpio_keys_remove(struct platform_device *pdev)
809{
810 sysfs_remove_group(&pdev->dev.kobj, &gpio_keys_attr_group);
811
812 device_init_wakeup(&pdev->dev, 0);
813
814 return 0;
815}
816
817#ifdef CONFIG_PM_SLEEP
818static int gpio_keys_suspend(struct device *dev)
819{
820 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
821 struct input_dev *input = ddata->input;
822 int i;
823
824 if (device_may_wakeup(dev)) {
825 for (i = 0; i < ddata->pdata->nbuttons; i++) {
826 struct gpio_button_data *bdata = &ddata->data[i];
827 if (bdata->button->wakeup)
828 enable_irq_wake(bdata->irq);
829 }
830 } else {
831 mutex_lock(&input->mutex);
832 if (input->users)
833 gpio_keys_close(input);
834 mutex_unlock(&input->mutex);
835 }
836
837 return 0;
838}
839
840static int gpio_keys_resume(struct device *dev)
841{
842 struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
843 struct input_dev *input = ddata->input;
844 int error = 0;
845 int i;
846
847 if (device_may_wakeup(dev)) {
848 for (i = 0; i < ddata->pdata->nbuttons; i++) {
849 struct gpio_button_data *bdata = &ddata->data[i];
850 if (bdata->button->wakeup)
851 disable_irq_wake(bdata->irq);
852 }
853 } else {
854 mutex_lock(&input->mutex);
855 if (input->users)
856 error = gpio_keys_open(input);
857 mutex_unlock(&input->mutex);
858 }
859
860 if (error)
861 return error;
862
863 gpio_keys_report_state(ddata);
864 return 0;
865}
866#endif
867
868static SIMPLE_DEV_PM_OPS(gpio_keys_pm_ops, gpio_keys_suspend, gpio_keys_resume);
869
870static struct platform_driver gpio_keys_device_driver = {
871 .probe = gpio_keys_probe,
872 .remove = gpio_keys_remove,
873 .driver = {
874 .name = "gpio-keys",
875 .pm = &gpio_keys_pm_ops,
876 .of_match_table = of_match_ptr(gpio_keys_of_match),
877 }
878};
879
880static int __init gpio_keys_init(void)
881{
882 return platform_driver_register(&gpio_keys_device_driver);
883}
884
885static void __exit gpio_keys_exit(void)
886{
887 platform_driver_unregister(&gpio_keys_device_driver);
888}
889
890late_initcall(gpio_keys_init);
891module_exit(gpio_keys_exit);
892
893MODULE_LICENSE("GPL");
894MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
895MODULE_DESCRIPTION("Keyboard driver for GPIOs");
896MODULE_ALIAS("platform:gpio-keys");