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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
32 #define BH_SKB_SIZE 2048
33
34 #define DRV_NAME "gpio-keys"
35 #define PFX DRV_NAME ": "
36
37 struct bh_priv {
38 unsigned long seen;
39 };
40
41 struct bh_event {
42 const char *name;
43 unsigned int type;
44 char *action;
45 unsigned long seen;
46
47 struct sk_buff *skb;
48 struct work_struct work;
49 };
50
51 struct bh_map {
52 unsigned int code;
53 const char *name;
54 };
55
56 struct gpio_keys_button_data {
57 struct delayed_work work;
58 struct bh_priv bh;
59 int last_state;
60 int count;
61 int threshold;
62 int can_sleep;
63 int irq;
64 unsigned int software_debounce;
65 struct gpio_desc *gpiod;
66 const struct gpio_keys_button *b;
67 };
68
69 extern u64 uevent_next_seqnum(void);
70
71 #define BH_MAP(_code, _name) \
72 { \
73 .code = (_code), \
74 .name = (_name), \
75 }
76
77 static struct bh_map button_map[] = {
78 BH_MAP(BTN_0, "BTN_0"),
79 BH_MAP(BTN_1, "BTN_1"),
80 BH_MAP(BTN_2, "BTN_2"),
81 BH_MAP(BTN_3, "BTN_3"),
82 BH_MAP(BTN_4, "BTN_4"),
83 BH_MAP(BTN_5, "BTN_5"),
84 BH_MAP(BTN_6, "BTN_6"),
85 BH_MAP(BTN_7, "BTN_7"),
86 BH_MAP(BTN_8, "BTN_8"),
87 BH_MAP(BTN_9, "BTN_9"),
88 BH_MAP(KEY_BRIGHTNESS_ZERO, "brightness_zero"),
89 BH_MAP(KEY_CONFIG, "config"),
90 BH_MAP(KEY_COPY, "copy"),
91 BH_MAP(KEY_EJECTCD, "eject"),
92 BH_MAP(KEY_HELP, "help"),
93 BH_MAP(KEY_LIGHTS_TOGGLE, "lights_toggle"),
94 BH_MAP(KEY_PHONE, "phone"),
95 BH_MAP(KEY_POWER, "power"),
96 BH_MAP(KEY_POWER2, "reboot"),
97 BH_MAP(KEY_RESTART, "reset"),
98 BH_MAP(KEY_RFKILL, "rfkill"),
99 BH_MAP(KEY_VIDEO, "video"),
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 static 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 void button_hotplug_event(struct gpio_keys_button_data *data,
241 unsigned int type, int value)
242 {
243 struct bh_priv *priv = &data->bh;
244 unsigned long seen = jiffies;
245 int btn;
246
247 pr_debug(PFX "event type=%u, code=%u, value=%d\n", type, data->b->code, value);
248
249 if ((type != EV_KEY) && (type != EV_SW))
250 return;
251
252 btn = button_get_index(data->b->code);
253 if (btn < 0)
254 return;
255
256 if (priv->seen == 0)
257 priv->seen = seen;
258
259 button_hotplug_create_event(button_map[btn].name, type,
260 (seen - priv->seen) / HZ, value);
261 priv->seen = seen;
262 }
263
264 struct gpio_keys_button_dev {
265 int polled;
266 struct delayed_work work;
267
268 struct device *dev;
269 struct gpio_keys_platform_data *pdata;
270 struct gpio_keys_button_data data[0];
271 };
272
273 static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
274 {
275 int val;
276
277 if (bdata->can_sleep)
278 val = !!gpio_get_value_cansleep(bdata->b->gpio);
279 else
280 val = !!gpio_get_value(bdata->b->gpio);
281
282 return val ^ bdata->b->active_low;
283 }
284
285 static void gpio_keys_polled_check_state(struct gpio_keys_button_data *bdata)
286 {
287 int state = gpio_button_get_value(bdata);
288
289 if (state != bdata->last_state) {
290 unsigned int type = bdata->b->type ?: EV_KEY;
291
292 if (bdata->count < bdata->threshold) {
293 bdata->count++;
294 return;
295 }
296
297 if (bdata->last_state != -1 || type == EV_SW)
298 button_hotplug_event(bdata, type, state);
299
300 bdata->last_state = state;
301 }
302
303 bdata->count = 0;
304 }
305
306 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
307 {
308 struct gpio_keys_platform_data *pdata = bdev->pdata;
309 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
310
311 if (delay >= HZ)
312 delay = round_jiffies_relative(delay);
313 schedule_delayed_work(&bdev->work, delay);
314 }
315
316 static void gpio_keys_polled_poll(struct work_struct *work)
317 {
318 struct gpio_keys_button_dev *bdev =
319 container_of(work, struct gpio_keys_button_dev, work.work);
320 int i;
321
322 for (i = 0; i < bdev->pdata->nbuttons; i++) {
323 struct gpio_keys_button_data *bdata = &bdev->data[i];
324 gpio_keys_polled_check_state(bdata);
325 }
326 gpio_keys_polled_queue_work(bdev);
327 }
328
329 static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev)
330 {
331 struct gpio_keys_platform_data *pdata = bdev->pdata;
332
333 cancel_delayed_work_sync(&bdev->work);
334
335 if (pdata->disable)
336 pdata->disable(bdev->dev);
337 }
338
339 static void gpio_keys_irq_work_func(struct work_struct *work)
340 {
341 struct gpio_keys_button_data *bdata = container_of(work,
342 struct gpio_keys_button_data, work.work);
343 int state = gpio_button_get_value(bdata);
344
345 if (state != bdata->last_state) {
346 unsigned int type = bdata->b->type ?: EV_KEY;
347
348 if (bdata->last_state != -1 || type == EV_SW)
349 button_hotplug_event(bdata, type, state);
350
351 bdata->last_state = state;
352 }
353 }
354
355 static irqreturn_t button_handle_irq(int irq, void *_bdata)
356 {
357 struct gpio_keys_button_data *bdata =
358 (struct gpio_keys_button_data *) _bdata;
359
360 schedule_delayed_work(&bdata->work,
361 msecs_to_jiffies(bdata->software_debounce));
362
363 return IRQ_HANDLED;
364 }
365
366 #ifdef CONFIG_OF
367 static struct gpio_keys_platform_data *
368 gpio_keys_get_devtree_pdata(struct device *dev)
369 {
370 struct device_node *node, *pp;
371 struct gpio_keys_platform_data *pdata;
372 struct gpio_keys_button *button;
373 int error;
374 int nbuttons;
375 int i = 0;
376
377 node = dev->of_node;
378 if (!node)
379 return NULL;
380
381 nbuttons = of_get_child_count(node);
382 if (nbuttons == 0)
383 return NULL;
384
385 pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * (sizeof *button),
386 GFP_KERNEL);
387 if (!pdata) {
388 error = -ENOMEM;
389 goto err_out;
390 }
391
392 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
393 pdata->nbuttons = nbuttons;
394
395 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
396 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
397
398 for_each_child_of_node(node, pp) {
399 enum of_gpio_flags flags;
400
401 if (!of_find_property(pp, "gpios", NULL)) {
402 pdata->nbuttons--;
403 dev_warn(dev, "Found button without gpios\n");
404 continue;
405 }
406
407 button = (struct gpio_keys_button *)(&pdata->buttons[i++]);
408
409 button->irq = irq_of_parse_and_map(pp, 0);
410
411 button->gpio = of_get_gpio_flags(pp, 0, &flags);
412 if (button->gpio < 0) {
413 error = button->gpio;
414 if (error != -ENOENT) {
415 if (error != -EPROBE_DEFER)
416 dev_err(dev,
417 "Failed to get gpio flags, error: %d\n",
418 error);
419 return ERR_PTR(error);
420 }
421 } else {
422 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
423 }
424
425 if (of_property_read_u32(pp, "linux,code", &button->code)) {
426 dev_err(dev, "Button without keycode: 0x%x\n",
427 button->gpio);
428 error = -EINVAL;
429 goto err_out;
430 }
431
432 button->desc = of_get_property(pp, "label", NULL);
433
434 if (of_property_read_u32(pp, "linux,input-type", &button->type))
435 button->type = EV_KEY;
436
437 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
438
439 if (of_property_read_u32(pp, "debounce-interval",
440 &button->debounce_interval))
441 button->debounce_interval = 5;
442 }
443
444 if (pdata->nbuttons == 0) {
445 error = -EINVAL;
446 goto err_out;
447 }
448
449 return pdata;
450
451 err_out:
452 return ERR_PTR(error);
453 }
454
455 static struct of_device_id gpio_keys_of_match[] = {
456 { .compatible = "gpio-keys", },
457 { },
458 };
459 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
460
461 static struct of_device_id gpio_keys_polled_of_match[] = {
462 { .compatible = "gpio-keys-polled", },
463 { },
464 };
465 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
466
467 #else
468
469 static inline struct gpio_keys_platform_data *
470 gpio_keys_get_devtree_pdata(struct device *dev)
471 {
472 return NULL;
473 }
474 #endif
475
476 static int gpio_keys_button_probe(struct platform_device *pdev,
477 struct gpio_keys_button_dev **_bdev, int polled)
478 {
479 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
480 struct device *dev = &pdev->dev;
481 struct gpio_keys_button_dev *bdev;
482 struct gpio_keys_button *buttons;
483 int error;
484 int i;
485
486 if (!pdata) {
487 pdata = gpio_keys_get_devtree_pdata(dev);
488 if (IS_ERR(pdata))
489 return PTR_ERR(pdata);
490 if (!pdata) {
491 dev_err(dev, "missing platform data\n");
492 return -EINVAL;
493 }
494 }
495
496 if (polled && !pdata->poll_interval) {
497 dev_err(dev, "missing poll_interval value\n");
498 return -EINVAL;
499 }
500
501 buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button),
502 GFP_KERNEL);
503 if (!buttons) {
504 dev_err(dev, "no memory for button data\n");
505 return -ENOMEM;
506 }
507 memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button));
508
509 bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) +
510 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
511 GFP_KERNEL);
512 if (!bdev) {
513 dev_err(dev, "no memory for private data\n");
514 return -ENOMEM;
515 }
516
517 bdev->polled = polled;
518
519 for (i = 0; i < pdata->nbuttons; i++) {
520 struct gpio_keys_button *button = &buttons[i];
521 struct gpio_keys_button_data *bdata = &bdev->data[i];
522 unsigned int gpio = button->gpio;
523
524 if (button->wakeup) {
525 dev_err(dev, DRV_NAME "does not support wakeup\n");
526 return -EINVAL;
527 }
528
529 error = devm_gpio_request(dev, gpio,
530 button->desc ? button->desc : DRV_NAME);
531 if (error) {
532 dev_err(dev, "unable to claim gpio %u, err=%d\n",
533 gpio, error);
534 return error;
535 }
536 bdata->gpiod = gpio_to_desc(gpio);
537 if (!bdata->gpiod)
538 return -EINVAL;
539
540 error = gpio_direction_input(gpio);
541 if (error) {
542 dev_err(dev,
543 "unable to set direction on gpio %u, err=%d\n",
544 gpio, error);
545 return error;
546 }
547
548 bdata->can_sleep = gpio_cansleep(gpio);
549 bdata->last_state = -1;
550
551 if (bdev->polled) {
552 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
553 pdata->poll_interval);
554 } else {
555 bdata->threshold = 1;
556
557 if (button->debounce_interval) {
558 error = gpiod_set_debounce(bdata->gpiod,
559 button->debounce_interval * 1000);
560 /*
561 * use timer if gpiolib doesn't provide
562 * debounce.
563 */
564 if (error < 0) {
565 bdata->software_debounce =
566 button->debounce_interval;
567 }
568 }
569 }
570
571 bdata->b = &pdata->buttons[i];
572 }
573
574 bdev->dev = &pdev->dev;
575 bdev->pdata = pdata;
576 platform_set_drvdata(pdev, bdev);
577
578 *_bdev = bdev;
579
580 return 0;
581 }
582
583 static int gpio_keys_probe(struct platform_device *pdev)
584 {
585 struct gpio_keys_platform_data *pdata;
586 struct gpio_keys_button_dev *bdev;
587 int ret, i;
588
589
590 ret = gpio_keys_button_probe(pdev, &bdev, 0);
591
592 if (ret)
593 return ret;
594
595 pdata = bdev->pdata;
596 for (i = 0; i < pdata->nbuttons; i++) {
597 const struct gpio_keys_button *button = &pdata->buttons[i];
598 struct gpio_keys_button_data *bdata = &bdev->data[i];
599 unsigned long irqflags = IRQF_ONESHOT;
600
601 if (!button->irq) {
602 bdata->irq = gpio_to_irq(button->gpio);
603
604 if (bdata->irq < 0) {
605 dev_err(&pdev->dev, "failed to get irq for gpio:%d\n",
606 button->gpio);
607 continue;
608 }
609
610 irqflags |= IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
611 } else {
612 bdata->irq = button->irq;
613 }
614
615 INIT_DELAYED_WORK(&bdata->work, gpio_keys_irq_work_func);
616
617 ret = devm_request_threaded_irq(&pdev->dev,
618 bdata->irq, NULL, button_handle_irq,
619 irqflags, dev_name(&pdev->dev), bdata);
620
621 if (ret < 0) {
622 bdata->irq = 0;
623 dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n",
624 bdata->irq, button->gpio);
625 continue;
626 } else {
627 dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n",
628 button->gpio, bdata->irq);
629 }
630
631 if (bdata->b->type == EV_SW)
632 button_hotplug_event(bdata, EV_SW, gpio_button_get_value(bdata));
633 }
634
635 return 0;
636 }
637
638 static int gpio_keys_polled_probe(struct platform_device *pdev)
639 {
640 struct gpio_keys_platform_data *pdata;
641 struct gpio_keys_button_dev *bdev;
642 int ret;
643 int i;
644
645 ret = gpio_keys_button_probe(pdev, &bdev, 1);
646
647 if (ret)
648 return ret;
649
650 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
651
652 pdata = bdev->pdata;
653
654 if (pdata->enable)
655 pdata->enable(bdev->dev);
656
657 for (i = 0; i < pdata->nbuttons; i++)
658 gpio_keys_polled_check_state(&bdev->data[i]);
659
660 gpio_keys_polled_queue_work(bdev);
661
662 return ret;
663 }
664
665 static void gpio_keys_irq_close(struct gpio_keys_button_dev *bdev)
666 {
667 struct gpio_keys_platform_data *pdata = bdev->pdata;
668 size_t i;
669
670 for (i = 0; i < pdata->nbuttons; i++) {
671 struct gpio_keys_button_data *bdata = &bdev->data[i];
672
673 disable_irq(bdata->irq);
674 cancel_delayed_work_sync(&bdata->work);
675 }
676 }
677
678 static int gpio_keys_remove(struct platform_device *pdev)
679 {
680 struct gpio_keys_button_dev *bdev = platform_get_drvdata(pdev);
681
682 platform_set_drvdata(pdev, NULL);
683
684 if (bdev->polled)
685 gpio_keys_polled_close(bdev);
686 else
687 gpio_keys_irq_close(bdev);
688
689 return 0;
690 }
691
692 static struct platform_driver gpio_keys_driver = {
693 .probe = gpio_keys_probe,
694 .remove = gpio_keys_remove,
695 .driver = {
696 .name = "gpio-keys",
697 .owner = THIS_MODULE,
698 .of_match_table = of_match_ptr(gpio_keys_of_match),
699 },
700 };
701
702 static struct platform_driver gpio_keys_polled_driver = {
703 .probe = gpio_keys_polled_probe,
704 .remove = gpio_keys_remove,
705 .driver = {
706 .name = "gpio-keys-polled",
707 .owner = THIS_MODULE,
708 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
709 },
710 };
711
712 static int __init gpio_button_init(void)
713 {
714 int ret;
715
716 ret = platform_driver_register(&gpio_keys_driver);
717 if (ret)
718 return ret;
719
720 ret = platform_driver_register(&gpio_keys_polled_driver);
721 if (ret)
722 platform_driver_unregister(&gpio_keys_driver);
723
724 return ret;
725 }
726
727 static void __exit gpio_button_exit(void)
728 {
729 platform_driver_unregister(&gpio_keys_driver);
730 platform_driver_unregister(&gpio_keys_polled_driver);
731 }
732
733 module_init(gpio_button_init);
734 module_exit(gpio_button_exit);
735
736 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
737 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
738 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
739 MODULE_LICENSE("GPL v2");
740 MODULE_ALIAS("platform:" DRV_NAME);
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