projects / openwrt / openwrt.git / blob
? search:


ad2e0ca863144aa7b95aeff9d8d791cf0d26f9eb
[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 BH_MAP(KEY_VENDOR, "vendor"),
104 };
105
106 /* -------------------------------------------------------------------------*/
107
108 static __printf(3, 4)
109 int bh_event_add_var(struct bh_event *event, int argv, const char *format, ...)
110 {
111 char buf[128];
112 char *s;
113 va_list args;
114 int len;
115
116 if (argv)
117 return 0;
118
119 va_start(args, format);
120 len = vsnprintf(buf, sizeof(buf), format, args);
121 va_end(args);
122
123 if (len >= sizeof(buf)) {
124 WARN(1, "buffer size too small");
125 return -ENOMEM;
126 }
127
128 s = skb_put(event->skb, len + 1);
129 strcpy(s, buf);
130
131 pr_debug(PFX "added variable '%s'\n", s);
132
133 return 0;
134 }
135
136 static int button_hotplug_fill_event(struct bh_event *event)
137 {
138 int ret;
139
140 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
141 if (ret)
142 return ret;
143
144 ret = bh_event_add_var(event, 0, "PATH=%s",
145 "/sbin:/bin:/usr/sbin:/usr/bin");
146 if (ret)
147 return ret;
148
149 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
150 if (ret)
151 return ret;
152
153 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
154 if (ret)
155 return ret;
156
157 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
158 if (ret)
159 return ret;
160
161 if (event->type == EV_SW) {
162 ret = bh_event_add_var(event, 0, "TYPE=%s", "switch");
163 if (ret)
164 return ret;
165 }
166
167 ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
168 if (ret)
169 return ret;
170
171 ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
172
173 return ret;
174 }
175
176 static void button_hotplug_work(struct work_struct *work)
177 {
178 struct bh_event *event = container_of(work, struct bh_event, work);
179 int ret = 0;
180
181 event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
182 if (!event->skb)
183 goto out_free_event;
184
185 ret = bh_event_add_var(event, 0, "%s@", event->action);
186 if (ret)
187 goto out_free_skb;
188
189 ret = button_hotplug_fill_event(event);
190 if (ret)
191 goto out_free_skb;
192
193 NETLINK_CB(event->skb).dst_group = 1;
194 broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
195
196 out_free_skb:
197 if (ret) {
198 pr_err(PFX "work error %d\n", ret);
199 kfree_skb(event->skb);
200 }
201 out_free_event:
202 kfree(event);
203 }
204
205 static int button_hotplug_create_event(const char *name, unsigned int type,
206 unsigned long seen, int pressed)
207 {
208 struct bh_event *event;
209
210 pr_debug(PFX "create event, name=%s, seen=%lu, pressed=%d\n",
211 name, seen, pressed);
212
213 event = kzalloc(sizeof(*event), GFP_KERNEL);
214 if (!event)
215 return -ENOMEM;
216
217 event->name = name;
218 event->type = type;
219 event->seen = seen;
220 event->action = pressed ? "pressed" : "released";
221
222 INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
223 schedule_work(&event->work);
224
225 return 0;
226 }
227
228 /* -------------------------------------------------------------------------*/
229
230 static int button_get_index(unsigned int code)
231 {
232 int i;
233
234 for (i = 0; i < ARRAY_SIZE(button_map); i++)
235 if (button_map[i].code == code)
236 return i;
237
238 return -1;
239 }
240
241 static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
242 {
243 int val;
244
245 if (bdata->can_sleep)
246 val = !!gpiod_get_value_cansleep(bdata->gpiod);
247 else
248 val = !!gpiod_get_value(bdata->gpiod);
249
250 return val;
251 }
252
253 static void gpio_keys_handle_button(struct gpio_keys_button_data *bdata)
254 {
255 unsigned int type = bdata->b->type ?: EV_KEY;
256 int state = gpio_button_get_value(bdata);
257 unsigned long seen = jiffies;
258
259 pr_debug(PFX "event type=%u, code=%u, pressed=%d\n",
260 type, bdata->b->code, state);
261
262 /* is this the initialization state? */
263 if (bdata->last_state == -1) {
264 /*
265 * Don't advertise unpressed buttons on initialization.
266 * Just save their state and continue otherwise this
267 * can cause OpenWrt to enter failsafe.
268 */
269 if (type == EV_KEY && state == 0)
270 goto set_state;
271 /*
272 * But we are very interested in pressed buttons and
273 * initial switch state. These will be reported to
274 * userland.
275 */
276 } else if (bdata->last_state == state) {
277 /* reset asserted counter (only relevant for polled keys) */
278 bdata->count = 0;
279 return;
280 }
281
282 if (bdata->count < bdata->threshold) {
283 bdata->count++;
284 return;
285 }
286
287 if (bdata->seen == 0)
288 bdata->seen = seen;
289
290 button_hotplug_create_event(button_map[bdata->map_entry].name, type,
291 (seen - bdata->seen) / HZ, state);
292 bdata->seen = seen;
293
294 set_state:
295 bdata->last_state = state;
296 bdata->count = 0;
297 }
298
299 struct gpio_keys_button_dev {
300 int polled;
301 struct delayed_work work;
302
303 struct device *dev;
304 struct gpio_keys_platform_data *pdata;
305 struct gpio_keys_button_data data[];
306 };
307
308 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
309 {
310 struct gpio_keys_platform_data *pdata = bdev->pdata;
311 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
312
313 if (delay >= HZ)
314 delay = round_jiffies_relative(delay);
315 schedule_delayed_work(&bdev->work, delay);
316 }
317
318 static void gpio_keys_polled_poll(struct work_struct *work)
319 {
320 struct gpio_keys_button_dev *bdev =
321 container_of(work, struct gpio_keys_button_dev, work.work);
322 int i;
323
324 for (i = 0; i < bdev->pdata->nbuttons; i++) {
325 struct gpio_keys_button_data *bdata = &bdev->data[i];
326
327 if (bdata->gpiod)
328 gpio_keys_handle_button(bdata);
329 }
330 gpio_keys_polled_queue_work(bdev);
331 }
332
333 static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev)
334 {
335 struct gpio_keys_platform_data *pdata = bdev->pdata;
336
337 cancel_delayed_work_sync(&bdev->work);
338
339 if (pdata->disable)
340 pdata->disable(bdev->dev);
341 }
342
343 static void gpio_keys_irq_work_func(struct work_struct *work)
344 {
345 struct gpio_keys_button_data *bdata = container_of(work,
346 struct gpio_keys_button_data, work.work);
347
348 gpio_keys_handle_button(bdata);
349 }
350
351 static irqreturn_t button_handle_irq(int irq, void *_bdata)
352 {
353 struct gpio_keys_button_data *bdata =
354 (struct gpio_keys_button_data *) _bdata;
355
356 mod_delayed_work(system_wq, &bdata->work,
357 msecs_to_jiffies(bdata->software_debounce));
358
359 return IRQ_HANDLED;
360 }
361
362 #ifdef CONFIG_OF
363 static struct gpio_keys_platform_data *
364 gpio_keys_get_devtree_pdata(struct device *dev)
365 {
366 struct device_node *node, *pp;
367 struct gpio_keys_platform_data *pdata;
368 struct gpio_keys_button *button;
369 int nbuttons;
370 int i = 0;
371
372 node = dev->of_node;
373 if (!node)
374 return NULL;
375
376 nbuttons = of_get_available_child_count(node);
377 if (nbuttons == 0)
378 return ERR_PTR(-EINVAL);
379
380 pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * (sizeof *button),
381 GFP_KERNEL);
382 if (!pdata)
383 return ERR_PTR(-ENOMEM);
384
385 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
386 pdata->nbuttons = nbuttons;
387
388 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
389 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
390
391 for_each_available_child_of_node(node, pp) {
392 button = (struct gpio_keys_button *)(&pdata->buttons[i++]);
393
394 if (of_property_read_u32(pp, "linux,code", &button->code)) {
395 dev_err(dev, "Button node '%s' without keycode\n",
396 pp->full_name);
397 of_node_put(pp);
398 return ERR_PTR(-EINVAL);
399 }
400
401 button->desc = of_get_property(pp, "label", NULL);
402
403 if (of_property_read_u32(pp, "linux,input-type", &button->type))
404 button->type = EV_KEY;
405
406 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
407
408 if (of_property_read_u32(pp, "debounce-interval",
409 &button->debounce_interval))
410 button->debounce_interval = 5;
411
412 button->irq = irq_of_parse_and_map(pp, 0);
413 button->gpio = -ENOENT; /* mark this as device-tree */
414 }
415
416 return pdata;
417 }
418
419 static struct of_device_id gpio_keys_of_match[] = {
420 { .compatible = "gpio-keys", },
421 { },
422 };
423 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
424
425 static struct of_device_id gpio_keys_polled_of_match[] = {
426 { .compatible = "gpio-keys-polled", },
427 { },
428 };
429 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
430
431 #else
432
433 static inline struct gpio_keys_platform_data *
434 gpio_keys_get_devtree_pdata(struct device *dev)
435 {
436 return NULL;
437 }
438 #endif
439
440 static int gpio_keys_button_probe(struct platform_device *pdev,
441 struct gpio_keys_button_dev **_bdev, int polled)
442 {
443 struct device *dev = &pdev->dev;
444 struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
445 struct gpio_keys_button_dev *bdev;
446 struct gpio_keys_button *buttons;
447 struct device_node *prev = NULL;
448 int error = 0;
449 int i;
450
451 if (!pdata) {
452 pdata = gpio_keys_get_devtree_pdata(dev);
453 if (IS_ERR(pdata))
454 return PTR_ERR(pdata);
455 if (!pdata) {
456 dev_err(dev, "missing platform data\n");
457 return -EINVAL;
458 }
459 }
460
461 if (polled && !pdata->poll_interval) {
462 dev_err(dev, "missing poll_interval value\n");
463 return -EINVAL;
464 }
465
466 buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button),
467 GFP_KERNEL);
468 if (!buttons) {
469 dev_err(dev, "no memory for button data\n");
470 return -ENOMEM;
471 }
472 memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button));
473
474 bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) +
475 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
476 GFP_KERNEL);
477 if (!bdev) {
478 dev_err(dev, "no memory for private data\n");
479 return -ENOMEM;
480 }
481
482 bdev->polled = polled;
483
484 for (i = 0; i < pdata->nbuttons; i++) {
485 struct gpio_keys_button *button = &buttons[i];
486 struct gpio_keys_button_data *bdata = &bdev->data[i];
487 const char *desc = button->desc ? button->desc : DRV_NAME;
488
489 if (button->wakeup) {
490 dev_err(dev, "does not support wakeup\n");
491 error = -EINVAL;
492 goto out;
493 }
494
495 bdata->map_entry = button_get_index(button->code);
496 if (bdata->map_entry < 0) {
497 dev_err(dev, "does not support key code:%u\n",
498 button->code);
499 error = -EINVAL;
500 goto out;
501 }
502
503 if (!(button->type == 0 || button->type == EV_KEY ||
504 button->type == EV_SW)) {
505 dev_err(dev, "only supports buttons or switches\n");
506 error = -EINVAL;
507 goto out;
508 }
509
510 if (button->irq) {
511 dev_err(dev, "skipping button %s (only gpio buttons supported)\n",
512 button->desc);
513 bdata->b = &pdata->buttons[i];
514 continue;
515 }
516
517 if (gpio_is_valid(button->gpio)) {
518 /* legacy platform data... but is it the lookup table? */
519 bdata->gpiod = devm_gpiod_get_index(dev, desc, i,
520 GPIOD_IN);
521 if (IS_ERR(bdata->gpiod)) {
522 /* or the legacy (button->gpio is good) way? */
523 error = devm_gpio_request_one(dev,
524 button->gpio, GPIOF_IN | (
525 button->active_low ? GPIOF_ACTIVE_LOW :
526 0), desc);
527 if (error) {
528 dev_err_probe(dev, error,
529 "unable to claim gpio %d",
530 button->gpio);
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 void 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
689 static struct platform_driver gpio_keys_driver = {
690 .probe = gpio_keys_probe,
691 .remove_new = gpio_keys_remove,
692 .driver = {
693 .name = "gpio-keys",
694 .of_match_table = of_match_ptr(gpio_keys_of_match),
695 },
696 };
697
698 static struct platform_driver gpio_keys_polled_driver = {
699 .probe = gpio_keys_polled_probe,
700 .remove_new = gpio_keys_remove,
701 .driver = {
702 .name = "gpio-keys-polled",
703 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
704 },
705 };
706
707 static int __init gpio_button_init(void)
708 {
709 int ret;
710
711 ret = platform_driver_register(&gpio_keys_driver);
712 if (ret)
713 return ret;
714
715 ret = platform_driver_register(&gpio_keys_polled_driver);
716 if (ret)
717 platform_driver_unregister(&gpio_keys_driver);
718
719 return ret;
720 }
721
722 static void __exit gpio_button_exit(void)
723 {
724 platform_driver_unregister(&gpio_keys_driver);
725 platform_driver_unregister(&gpio_keys_polled_driver);
726 }
727
728 module_init(gpio_button_init);
729 module_exit(gpio_button_exit);
730
731 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
732 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
733 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
734 MODULE_LICENSE("GPL v2");
735 MODULE_ALIAS("platform:" DRV_NAME);
OpenWrt Source Repository