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