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[openwrt/openwrt.git] / package / kernel / gpio-button-hotplug / src / gpio-button-hotplug.c
1 /*
2 * GPIO Button Hotplug driver
3 *
4 * Copyright (C) 2012 Felix Fietkau <nbd@nbd.name>
5 * Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
6 *
7 * Based on the diag.c - GPIO interface driver for Broadcom boards
8 * Copyright (C) 2006 Mike Baker <mbm@openwrt.org>,
9 * Copyright (C) 2006-2007 Felix Fietkau <nbd@nbd.name>
10 * Copyright (C) 2008 Andy Boyett <agb@openwrt.org>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License version 2 as published
14 * by the Free Software Foundation.
15 */
16
17 #include <linux/module.h>
18 #include <linux/version.h>
19 #include <linux/kmod.h>
20
21 #include <linux/workqueue.h>
22 #include <linux/skbuff.h>
23 #include <linux/netlink.h>
24 #include <linux/kobject.h>
25 #include <linux/input.h>
26 #include <linux/interrupt.h>
27 #include <linux/platform_device.h>
28 #include <linux/of_gpio.h>
29 #include <linux/of_irq.h>
30 #include <linux/gpio_keys.h>
31 #include <linux/gpio/consumer.h>
32
33 #define BH_SKB_SIZE 2048
34
35 #define DRV_NAME "gpio-keys"
36 #define PFX DRV_NAME ": "
37
38 struct bh_event {
39 const char *name;
40 unsigned int type;
41 char *action;
42 unsigned long seen;
43
44 struct sk_buff *skb;
45 struct work_struct work;
46 };
47
48 struct bh_map {
49 unsigned int code;
50 const char *name;
51 };
52
53 struct gpio_keys_button_data {
54 struct delayed_work work;
55 unsigned long seen;
56 int map_entry;
57 int last_state;
58 int count;
59 int threshold;
60 int can_sleep;
61 int irq;
62 unsigned int software_debounce;
63 struct gpio_desc *gpiod;
64 const struct gpio_keys_button *b;
65 };
66
67 extern u64 uevent_next_seqnum(void);
68
69 #define BH_MAP(_code, _name) \
70 { \
71 .code = (_code), \
72 .name = (_name), \
73 }
74
75 static struct bh_map button_map[] = {
76 BH_MAP(BTN_0, "BTN_0"),
77 BH_MAP(BTN_1, "BTN_1"),
78 BH_MAP(BTN_2, "BTN_2"),
79 BH_MAP(BTN_3, "BTN_3"),
80 BH_MAP(BTN_4, "BTN_4"),
81 BH_MAP(BTN_5, "BTN_5"),
82 BH_MAP(BTN_6, "BTN_6"),
83 BH_MAP(BTN_7, "BTN_7"),
84 BH_MAP(BTN_8, "BTN_8"),
85 BH_MAP(BTN_9, "BTN_9"),
86 BH_MAP(KEY_BRIGHTNESS_ZERO, "brightness_zero"),
87 BH_MAP(KEY_CONFIG, "config"),
88 BH_MAP(KEY_COPY, "copy"),
89 BH_MAP(KEY_EJECTCD, "eject"),
90 BH_MAP(KEY_HELP, "help"),
91 BH_MAP(KEY_LIGHTS_TOGGLE, "lights_toggle"),
92 BH_MAP(KEY_PHONE, "phone"),
93 BH_MAP(KEY_POWER, "power"),
94 BH_MAP(KEY_POWER2, "reboot"),
95 BH_MAP(KEY_RESTART, "reset"),
96 BH_MAP(KEY_RFKILL, "rfkill"),
97 BH_MAP(KEY_VIDEO, "video"),
98 BH_MAP(KEY_VOLUMEDOWN, "volume_down"),
99 BH_MAP(KEY_VOLUMEUP, "volume_up"),
100 BH_MAP(KEY_WIMAX, "wwan"),
101 BH_MAP(KEY_WLAN, "wlan"),
102 BH_MAP(KEY_WPS_BUTTON, "wps"),
103 };
104
105 /* -------------------------------------------------------------------------*/
106
107 static __printf(3, 4)
108 int bh_event_add_var(struct bh_event *event, int argv, const char *format, ...)
109 {
110 char buf[128];
111 char *s;
112 va_list args;
113 int len;
114
115 if (argv)
116 return 0;
117
118 va_start(args, format);
119 len = vsnprintf(buf, sizeof(buf), format, args);
120 va_end(args);
121
122 if (len >= sizeof(buf)) {
123 WARN(1, "buffer size too small");
124 return -ENOMEM;
125 }
126
127 s = skb_put(event->skb, len + 1);
128 strcpy(s, buf);
129
130 pr_debug(PFX "added variable '%s'\n", s);
131
132 return 0;
133 }
134
135 static int button_hotplug_fill_event(struct bh_event *event)
136 {
137 int ret;
138
139 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
140 if (ret)
141 return ret;
142
143 ret = bh_event_add_var(event, 0, "PATH=%s",
144 "/sbin:/bin:/usr/sbin:/usr/bin");
145 if (ret)
146 return ret;
147
148 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
149 if (ret)
150 return ret;
151
152 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
153 if (ret)
154 return ret;
155
156 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
157 if (ret)
158 return ret;
159
160 if (event->type == EV_SW) {
161 ret = bh_event_add_var(event, 0, "TYPE=%s", "switch");
162 if (ret)
163 return ret;
164 }
165
166 ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
167 if (ret)
168 return ret;
169
170 ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
171
172 return ret;
173 }
174
175 static void button_hotplug_work(struct work_struct *work)
176 {
177 struct bh_event *event = container_of(work, struct bh_event, work);
178 int ret = 0;
179
180 event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
181 if (!event->skb)
182 goto out_free_event;
183
184 ret = bh_event_add_var(event, 0, "%s@", event->action);
185 if (ret)
186 goto out_free_skb;
187
188 ret = button_hotplug_fill_event(event);
189 if (ret)
190 goto out_free_skb;
191
192 NETLINK_CB(event->skb).dst_group = 1;
193 broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
194
195 out_free_skb:
196 if (ret) {
197 pr_err(PFX "work error %d\n", ret);
198 kfree_skb(event->skb);
199 }
200 out_free_event:
201 kfree(event);
202 }
203
204 static int button_hotplug_create_event(const char *name, unsigned int type,
205 unsigned long seen, int pressed)
206 {
207 struct bh_event *event;
208
209 pr_debug(PFX "create event, name=%s, seen=%lu, pressed=%d\n",
210 name, seen, pressed);
211
212 event = kzalloc(sizeof(*event), GFP_KERNEL);
213 if (!event)
214 return -ENOMEM;
215
216 event->name = name;
217 event->type = type;
218 event->seen = seen;
219 event->action = pressed ? "pressed" : "released";
220
221 INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
222 schedule_work(&event->work);
223
224 return 0;
225 }
226
227 /* -------------------------------------------------------------------------*/
228
229 static int button_get_index(unsigned int code)
230 {
231 int i;
232
233 for (i = 0; i < ARRAY_SIZE(button_map); i++)
234 if (button_map[i].code == code)
235 return i;
236
237 return -1;
238 }
239
240 static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
241 {
242 int val;
243
244 if (bdata->can_sleep)
245 val = !!gpiod_get_value_cansleep(bdata->gpiod);
246 else
247 val = !!gpiod_get_value(bdata->gpiod);
248
249 return val;
250 }
251
252 static void gpio_keys_handle_button(struct gpio_keys_button_data *bdata)
253 {
254 unsigned int type = bdata->b->type ?: EV_KEY;
255 int state = gpio_button_get_value(bdata);
256 unsigned long seen = jiffies;
257
258 pr_debug(PFX "event type=%u, code=%u, pressed=%d\n",
259 type, bdata->b->code, state);
260
261 /* is this the initialization state? */
262 if (bdata->last_state == -1) {
263 /*
264 * Don't advertise unpressed buttons on initialization.
265 * Just save their state and continue otherwise this
266 * can cause OpenWrt to enter failsafe.
267 */
268 if (type == EV_KEY && state == 0)
269 goto set_state;
270 /*
271 * But we are very interested in pressed buttons and
272 * initial switch state. These will be reported to
273 * userland.
274 */
275 } else if (bdata->last_state == state) {
276 /* reset asserted counter (only relevant for polled keys) */
277 bdata->count = 0;
278 return;
279 }
280
281 if (bdata->count < bdata->threshold) {
282 bdata->count++;
283 return;
284 }
285
286 if (bdata->seen == 0)
287 bdata->seen = seen;
288
289 button_hotplug_create_event(button_map[bdata->map_entry].name, type,
290 (seen - bdata->seen) / HZ, state);
291 bdata->seen = seen;
292
293 set_state:
294 bdata->last_state = state;
295 bdata->count = 0;
296 }
297
298 struct gpio_keys_button_dev {
299 int polled;
300 struct delayed_work work;
301
302 struct device *dev;
303 struct gpio_keys_platform_data *pdata;
304 struct gpio_keys_button_data data[0];
305 };
306
307 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
308 {
309 struct gpio_keys_platform_data *pdata = bdev->pdata;
310 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
311
312 if (delay >= HZ)
313 delay = round_jiffies_relative(delay);
314 schedule_delayed_work(&bdev->work, delay);
315 }
316
317 static void gpio_keys_polled_poll(struct work_struct *work)
318 {
319 struct gpio_keys_button_dev *bdev =
320 container_of(work, struct gpio_keys_button_dev, work.work);
321 int i;
322
323 for (i = 0; i < bdev->pdata->nbuttons; i++) {
324 struct gpio_keys_button_data *bdata = &bdev->data[i];
325
326 if (bdata->gpiod)
327 gpio_keys_handle_button(bdata);
328 }
329 gpio_keys_polled_queue_work(bdev);
330 }
331
332 static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev)
333 {
334 struct gpio_keys_platform_data *pdata = bdev->pdata;
335
336 cancel_delayed_work_sync(&bdev->work);
337
338 if (pdata->disable)
339 pdata->disable(bdev->dev);
340 }
341
342 static void gpio_keys_irq_work_func(struct work_struct *work)
343 {
344 struct gpio_keys_button_data *bdata = container_of(work,
345 struct gpio_keys_button_data, work.work);
346
347 gpio_keys_handle_button(bdata);
348 }
349
350 static irqreturn_t button_handle_irq(int irq, void *_bdata)
351 {
352 struct gpio_keys_button_data *bdata =
353 (struct gpio_keys_button_data *) _bdata;
354
355 mod_delayed_work(system_wq, &bdata->work,
356 msecs_to_jiffies(bdata->software_debounce));
357
358 return IRQ_HANDLED;
359 }
360
361 #ifdef CONFIG_OF
362 static struct gpio_keys_platform_data *
363 gpio_keys_get_devtree_pdata(struct device *dev)
364 {
365 struct device_node *node, *pp;
366 struct gpio_keys_platform_data *pdata;
367 struct gpio_keys_button *button;
368 int nbuttons;
369 int i = 0;
370
371 node = dev->of_node;
372 if (!node)
373 return NULL;
374
375 nbuttons = of_get_child_count(node);
376 if (nbuttons == 0)
377 return ERR_PTR(-EINVAL);
378
379 pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * (sizeof *button),
380 GFP_KERNEL);
381 if (!pdata)
382 return ERR_PTR(-ENOMEM);
383
384 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
385 pdata->nbuttons = nbuttons;
386
387 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
388 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
389
390 for_each_child_of_node(node, pp) {
391 button = (struct gpio_keys_button *)(&pdata->buttons[i++]);
392
393 if (of_property_read_u32(pp, "linux,code", &button->code)) {
394 dev_err(dev, "Button node '%s' without keycode\n",
395 pp->full_name);
396 of_node_put(pp);
397 return ERR_PTR(-EINVAL);
398 }
399
400 button->desc = of_get_property(pp, "label", NULL);
401
402 if (of_property_read_u32(pp, "linux,input-type", &button->type))
403 button->type = EV_KEY;
404
405 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
406
407 if (of_property_read_u32(pp, "debounce-interval",
408 &button->debounce_interval))
409 button->debounce_interval = 5;
410
411 button->irq = irq_of_parse_and_map(pp, 0);
412 button->gpio = -ENOENT; /* mark this as device-tree */
413 }
414
415 return pdata;
416 }
417
418 static struct of_device_id gpio_keys_of_match[] = {
419 { .compatible = "gpio-keys", },
420 { },
421 };
422 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
423
424 static struct of_device_id gpio_keys_polled_of_match[] = {
425 { .compatible = "gpio-keys-polled", },
426 { },
427 };
428 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
429
430 #else
431
432 static inline struct gpio_keys_platform_data *
433 gpio_keys_get_devtree_pdata(struct device *dev)
434 {
435 return NULL;
436 }
437 #endif
438
439 static int gpio_keys_button_probe(struct platform_device *pdev,
440 struct gpio_keys_button_dev **_bdev, int polled)
441 {
442 struct device *dev = &pdev->dev;
443 struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
444 struct gpio_keys_button_dev *bdev;
445 struct gpio_keys_button *buttons;
446 struct device_node *prev = NULL;
447 int error = 0;
448 int i;
449
450 if (!pdata) {
451 pdata = gpio_keys_get_devtree_pdata(dev);
452 if (IS_ERR(pdata))
453 return PTR_ERR(pdata);
454 if (!pdata) {
455 dev_err(dev, "missing platform data\n");
456 return -EINVAL;
457 }
458 }
459
460 if (polled && !pdata->poll_interval) {
461 dev_err(dev, "missing poll_interval value\n");
462 return -EINVAL;
463 }
464
465 buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button),
466 GFP_KERNEL);
467 if (!buttons) {
468 dev_err(dev, "no memory for button data\n");
469 return -ENOMEM;
470 }
471 memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button));
472
473 bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) +
474 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
475 GFP_KERNEL);
476 if (!bdev) {
477 dev_err(dev, "no memory for private data\n");
478 return -ENOMEM;
479 }
480
481 bdev->polled = polled;
482
483 for (i = 0; i < pdata->nbuttons; i++) {
484 struct gpio_keys_button *button = &buttons[i];
485 struct gpio_keys_button_data *bdata = &bdev->data[i];
486 const char *desc = button->desc ? button->desc : DRV_NAME;
487
488 if (button->wakeup) {
489 dev_err(dev, "does not support wakeup\n");
490 error = -EINVAL;
491 goto out;
492 }
493
494 bdata->map_entry = button_get_index(button->code);
495 if (bdata->map_entry < 0) {
496 dev_err(dev, "does not support key code:%u\n",
497 button->code);
498 error = -EINVAL;
499 goto out;
500 }
501
502 if (!(button->type == 0 || button->type == EV_KEY ||
503 button->type == EV_SW)) {
504 dev_err(dev, "only supports buttons or switches\n");
505 error = -EINVAL;
506 goto out;
507 }
508
509 if (button->irq) {
510 dev_err(dev, "skipping button %s (only gpio buttons supported)\n",
511 button->desc);
512 bdata->b = &pdata->buttons[i];
513 continue;
514 }
515
516 if (gpio_is_valid(button->gpio)) {
517 /* legacy platform data... but is it the lookup table? */
518 bdata->gpiod = devm_gpiod_get_index(dev, desc, i,
519 GPIOD_IN);
520 if (IS_ERR(bdata->gpiod)) {
521 /* or the legacy (button->gpio is good) way? */
522 error = devm_gpio_request_one(dev,
523 button->gpio, GPIOF_IN | (
524 button->active_low ? GPIOF_ACTIVE_LOW :
525 0), desc);
526 if (error) {
527 if (error != -EPROBE_DEFER) {
528 dev_err(dev, "unable to claim gpio %d, err=%d\n",
529 button->gpio, error);
530 }
531 goto out;
532 }
533
534 bdata->gpiod = gpio_to_desc(button->gpio);
535 }
536 } else {
537 /* Device-tree */
538 struct device_node *child =
539 of_get_next_child(dev->of_node, prev);
540
541 bdata->gpiod = devm_fwnode_gpiod_get(dev,
542 of_fwnode_handle(child), NULL, GPIOD_IN,
543 desc);
544
545 prev = child;
546 }
547
548 if (IS_ERR_OR_NULL(bdata->gpiod)) {
549 error = IS_ERR(bdata->gpiod) ? PTR_ERR(bdata->gpiod) :
550 -EINVAL;
551 goto out;
552 }
553
554 bdata->can_sleep = gpiod_cansleep(bdata->gpiod);
555 bdata->last_state = -1; /* Unknown state on boot */
556
557 if (bdev->polled) {
558 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
559 pdata->poll_interval);
560 } else {
561 /* bdata->threshold = 0; already initialized */
562
563 if (button->debounce_interval) {
564 error = gpiod_set_debounce(bdata->gpiod,
565 button->debounce_interval * 1000);
566 /*
567 * use timer if gpiolib doesn't provide
568 * debounce.
569 */
570 if (error < 0) {
571 bdata->software_debounce =
572 button->debounce_interval;
573 }
574 }
575 }
576
577 bdata->b = &pdata->buttons[i];
578 }
579
580 bdev->dev = &pdev->dev;
581 bdev->pdata = pdata;
582 platform_set_drvdata(pdev, bdev);
583
584 *_bdev = bdev;
585 error = 0;
586
587 out:
588 of_node_put(prev);
589 return error;
590 }
591
592 static int gpio_keys_probe(struct platform_device *pdev)
593 {
594 struct gpio_keys_platform_data *pdata;
595 struct gpio_keys_button_dev *bdev;
596 int ret, i;
597
598 ret = gpio_keys_button_probe(pdev, &bdev, 0);
599 if (ret)
600 return ret;
601
602 pdata = bdev->pdata;
603 for (i = 0; i < pdata->nbuttons; i++) {
604 const struct gpio_keys_button *button = &pdata->buttons[i];
605 struct gpio_keys_button_data *bdata = &bdev->data[i];
606 unsigned long irqflags = IRQF_ONESHOT;
607
608 INIT_DELAYED_WORK(&bdata->work, gpio_keys_irq_work_func);
609
610 if (!button->irq) {
611 bdata->irq = gpiod_to_irq(bdata->gpiod);
612 if (bdata->irq < 0) {
613 dev_err(&pdev->dev, "failed to get irq for gpio:%d\n",
614 button->gpio);
615 continue;
616 }
617
618 irqflags |= IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
619 } else {
620 bdata->irq = button->irq;
621 }
622
623 schedule_delayed_work(&bdata->work,
624 msecs_to_jiffies(bdata->software_debounce));
625
626 ret = devm_request_threaded_irq(&pdev->dev,
627 bdata->irq, NULL, button_handle_irq,
628 irqflags, dev_name(&pdev->dev), bdata);
629 if (ret < 0) {
630 bdata->irq = 0;
631 dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n",
632 bdata->irq, button->gpio);
633 continue;
634 } else {
635 dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n",
636 button->gpio, bdata->irq);
637 }
638 }
639
640 return 0;
641 }
642
643 static int gpio_keys_polled_probe(struct platform_device *pdev)
644 {
645 struct gpio_keys_platform_data *pdata;
646 struct gpio_keys_button_dev *bdev;
647 int ret;
648
649 ret = gpio_keys_button_probe(pdev, &bdev, 1);
650 if (ret)
651 return ret;
652
653 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
654
655 pdata = bdev->pdata;
656 if (pdata->enable)
657 pdata->enable(bdev->dev);
658
659 gpio_keys_polled_queue_work(bdev);
660
661 return ret;
662 }
663
664 static void gpio_keys_irq_close(struct gpio_keys_button_dev *bdev)
665 {
666 struct gpio_keys_platform_data *pdata = bdev->pdata;
667 size_t i;
668
669 for (i = 0; i < pdata->nbuttons; i++) {
670 struct gpio_keys_button_data *bdata = &bdev->data[i];
671
672 disable_irq(bdata->irq);
673 cancel_delayed_work_sync(&bdata->work);
674 }
675 }
676
677 static int gpio_keys_remove(struct platform_device *pdev)
678 {
679 struct gpio_keys_button_dev *bdev = platform_get_drvdata(pdev);
680
681 platform_set_drvdata(pdev, NULL);
682
683 if (bdev->polled)
684 gpio_keys_polled_close(bdev);
685 else
686 gpio_keys_irq_close(bdev);
687
688 return 0;
689 }
690
691 static struct platform_driver gpio_keys_driver = {
692 .probe = gpio_keys_probe,
693 .remove = gpio_keys_remove,
694 .driver = {
695 .name = "gpio-keys",
696 .owner = THIS_MODULE,
697 .of_match_table = of_match_ptr(gpio_keys_of_match),
698 },
699 };
700
701 static struct platform_driver gpio_keys_polled_driver = {
702 .probe = gpio_keys_polled_probe,
703 .remove = gpio_keys_remove,
704 .driver = {
705 .name = "gpio-keys-polled",
706 .owner = THIS_MODULE,
707 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
708 },
709 };
710
711 static int __init gpio_button_init(void)
712 {
713 int ret;
714
715 ret = platform_driver_register(&gpio_keys_driver);
716 if (ret)
717 return ret;
718
719 ret = platform_driver_register(&gpio_keys_polled_driver);
720 if (ret)
721 platform_driver_unregister(&gpio_keys_driver);
722
723 return ret;
724 }
725
726 static void __exit gpio_button_exit(void)
727 {
728 platform_driver_unregister(&gpio_keys_driver);
729 platform_driver_unregister(&gpio_keys_polled_driver);
730 }
731
732 module_init(gpio_button_init);
733 module_exit(gpio_button_exit);
734
735 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
736 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
737 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
738 MODULE_LICENSE("GPL v2");
739 MODULE_ALIAS("platform:" DRV_NAME);
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