gpio-button-hotplug: add support for power buttons
[openwrt/svn-archive/archive.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@openwrt.org>
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@openwrt.org>
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/platform_device.h>
27 #include <linux/of_gpio.h>
28 #include <linux/gpio_keys.h>
29
30 #define DRV_NAME "gpio-keys-polled"
31
32 #define BH_SKB_SIZE 2048
33
34 #define PFX DRV_NAME ": "
35
36 #undef BH_DEBUG
37
38 #ifdef BH_DEBUG
39 #define BH_DBG(fmt, args...) printk(KERN_DEBUG "%s: " fmt, DRV_NAME, ##args )
40 #else
41 #define BH_DBG(fmt, args...) do {} while (0)
42 #endif
43
44 #define BH_ERR(fmt, args...) printk(KERN_ERR "%s: " fmt, DRV_NAME, ##args )
45
46 struct bh_priv {
47 unsigned long seen;
48 };
49
50 struct bh_event {
51 const char *name;
52 unsigned int type;
53 char *action;
54 unsigned long seen;
55
56 struct sk_buff *skb;
57 struct work_struct work;
58 };
59
60 struct bh_map {
61 unsigned int code;
62 const char *name;
63 };
64
65 struct gpio_keys_button_data {
66 struct delayed_work work;
67 struct bh_priv bh;
68 int last_state;
69 int count;
70 int threshold;
71 int can_sleep;
72 };
73
74 extern u64 uevent_next_seqnum(void);
75
76 #define BH_MAP(_code, _name) \
77 { \
78 .code = (_code), \
79 .name = (_name), \
80 }
81
82 static struct bh_map button_map[] = {
83 BH_MAP(BTN_0, "BTN_0"),
84 BH_MAP(BTN_1, "BTN_1"),
85 BH_MAP(BTN_2, "BTN_2"),
86 BH_MAP(BTN_3, "BTN_3"),
87 BH_MAP(BTN_4, "BTN_4"),
88 BH_MAP(BTN_5, "BTN_5"),
89 BH_MAP(BTN_6, "BTN_6"),
90 BH_MAP(BTN_7, "BTN_7"),
91 BH_MAP(BTN_8, "BTN_8"),
92 BH_MAP(BTN_9, "BTN_9"),
93 BH_MAP(KEY_POWER, "power"),
94 BH_MAP(KEY_RESTART, "reset"),
95 BH_MAP(KEY_RFKILL, "rfkill"),
96 BH_MAP(KEY_WPS_BUTTON, "wps"),
97 };
98
99 /* -------------------------------------------------------------------------*/
100
101 static int bh_event_add_var(struct bh_event *event, int argv,
102 const char *format, ...)
103 {
104 static char buf[128];
105 char *s;
106 va_list args;
107 int len;
108
109 if (argv)
110 return 0;
111
112 va_start(args, format);
113 len = vsnprintf(buf, sizeof(buf), format, args);
114 va_end(args);
115
116 if (len >= sizeof(buf)) {
117 BH_ERR("buffer size too small\n");
118 WARN_ON(1);
119 return -ENOMEM;
120 }
121
122 s = skb_put(event->skb, len + 1);
123 strcpy(s, buf);
124
125 BH_DBG("added variable '%s'\n", s);
126
127 return 0;
128 }
129
130 static int button_hotplug_fill_event(struct bh_event *event)
131 {
132 char *s;
133 int ret;
134
135 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
136 if (ret)
137 return ret;
138
139 ret = bh_event_add_var(event, 0, "PATH=%s",
140 "/sbin:/bin:/usr/sbin:/usr/bin");
141 if (ret)
142 return ret;
143
144 switch (event->type) {
145 case EV_SW:
146 s = "switch";
147 break;
148 case EV_KEY:
149 default:
150 s = "button";
151 break;
152 }
153
154 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", s);
155 if (ret)
156 return ret;
157
158 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
159 if (ret)
160 return ret;
161
162 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
163 if (ret)
164 return ret;
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 BH_ERR("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 BH_DBG("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 #ifdef CONFIG_HOTPLUG
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 void button_hotplug_event(struct gpio_keys_button_data *data,
242 unsigned int type, unsigned int code, int value)
243 {
244 struct bh_priv *priv = &data->bh;
245 unsigned long seen = jiffies;
246 int btn;
247
248 BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
249
250 if ((type != EV_KEY) && (type != EV_SW))
251 return;
252
253 btn = button_get_index(code);
254 if (btn < 0)
255 return;
256
257 button_hotplug_create_event(button_map[btn].name, type,
258 (seen - priv->seen) / HZ, value);
259 priv->seen = seen;
260 }
261 #else
262 static void button_hotplug_event(struct gpio_keys_button_data *data,
263 unsigned int type, unsigned int code, int value)
264 {
265 }
266 #endif /* CONFIG_HOTPLUG */
267
268 struct gpio_keys_polled_dev {
269 struct delayed_work work;
270
271 struct device *dev;
272 struct gpio_keys_platform_data *pdata;
273 struct gpio_keys_button_data data[0];
274 };
275
276 static int gpio_button_get_value(struct gpio_keys_button *button,
277 struct gpio_keys_button_data *bdata)
278 {
279 int val;
280
281 if (bdata->can_sleep)
282 val = !!gpio_get_value_cansleep(button->gpio);
283 else
284 val = !!gpio_get_value(button->gpio);
285
286 return val ^ button->active_low;
287 }
288
289 static void gpio_keys_polled_check_state(struct gpio_keys_button *button,
290 struct gpio_keys_button_data *bdata)
291 {
292 int state = gpio_button_get_value(button, bdata);
293
294 if (state != bdata->last_state) {
295 unsigned int type = button->type ?: EV_KEY;
296
297 if (bdata->count < bdata->threshold) {
298 bdata->count++;
299 return;
300 }
301
302 if (bdata->last_state != -1)
303 button_hotplug_event(bdata, type, button->code, state);
304
305 bdata->last_state = state;
306 }
307
308 bdata->count = 0;
309 }
310
311 static void gpio_keys_polled_queue_work(struct gpio_keys_polled_dev *bdev)
312 {
313 struct gpio_keys_platform_data *pdata = bdev->pdata;
314 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
315
316 if (delay >= HZ)
317 delay = round_jiffies_relative(delay);
318 schedule_delayed_work(&bdev->work, delay);
319 }
320
321 static void gpio_keys_polled_poll(struct work_struct *work)
322 {
323 struct gpio_keys_polled_dev *bdev =
324 container_of(work, struct gpio_keys_polled_dev, work.work);
325 struct gpio_keys_platform_data *pdata = bdev->pdata;
326 int i;
327
328 for (i = 0; i < bdev->pdata->nbuttons; i++) {
329 struct gpio_keys_button_data *bdata = &bdev->data[i];
330 gpio_keys_polled_check_state(&pdata->buttons[i], bdata);
331 }
332 gpio_keys_polled_queue_work(bdev);
333 }
334
335 static void gpio_keys_polled_open(struct gpio_keys_polled_dev *bdev)
336 {
337 struct gpio_keys_platform_data *pdata = bdev->pdata;
338 int i;
339
340 if (pdata->enable)
341 pdata->enable(bdev->dev);
342
343 /* report initial state of the buttons */
344 for (i = 0; i < pdata->nbuttons; i++)
345 gpio_keys_polled_check_state(&pdata->buttons[i], &bdev->data[i]);
346
347 gpio_keys_polled_queue_work(bdev);
348 }
349
350 #ifdef CONFIG_OF
351 static struct gpio_keys_platform_data *
352 gpio_keys_polled_get_devtree_pdata(struct device *dev)
353 {
354 struct device_node *node, *pp;
355 struct gpio_keys_platform_data *pdata;
356 struct gpio_keys_button *button;
357 int error;
358 int nbuttons;
359 int i;
360
361 node = dev->of_node;
362 if (!node)
363 return NULL;
364
365 nbuttons = of_get_child_count(node);
366 if (nbuttons == 0)
367 return NULL;
368
369 pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
370 GFP_KERNEL);
371 if (!pdata) {
372 error = -ENOMEM;
373 goto err_out;
374 }
375
376 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
377 pdata->nbuttons = nbuttons;
378
379 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
380 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
381
382 i = 0;
383 for_each_child_of_node(node, pp) {
384 enum of_gpio_flags flags;
385
386 if (!of_find_property(pp, "gpios", NULL)) {
387 pdata->nbuttons--;
388 dev_warn(dev, "Found button without gpios\n");
389 continue;
390 }
391
392 button = &pdata->buttons[i++];
393
394 button->gpio = of_get_gpio_flags(pp, 0, &flags);
395 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
396
397 if (of_property_read_u32(pp, "linux,code", &button->code)) {
398 dev_err(dev, "Button without keycode: 0x%x\n",
399 button->gpio);
400 error = -EINVAL;
401 goto err_free_pdata;
402 }
403
404 button->desc = of_get_property(pp, "label", NULL);
405
406 if (of_property_read_u32(pp, "linux,input-type", &button->type))
407 button->type = EV_KEY;
408
409 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
410
411 if (of_property_read_u32(pp, "debounce-interval",
412 &button->debounce_interval))
413 button->debounce_interval = 5;
414 }
415
416 if (pdata->nbuttons == 0) {
417 error = -EINVAL;
418 goto err_free_pdata;
419 }
420
421 return pdata;
422
423 err_free_pdata:
424 kfree(pdata);
425 err_out:
426 return ERR_PTR(error);
427 }
428
429 static struct of_device_id gpio_keys_polled_of_match[] = {
430 { .compatible = "gpio-keys-polled", },
431 { },
432 };
433 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
434
435 #else
436
437 static inline struct gpio_keys_platform_data *
438 gpio_keys_polled_get_devtree_pdata(struct device *dev)
439 {
440 return NULL;
441 }
442 #endif
443
444 static void gpio_keys_polled_close(struct gpio_keys_polled_dev *bdev)
445 {
446 struct gpio_keys_platform_data *pdata = bdev->pdata;
447
448 cancel_delayed_work_sync(&bdev->work);
449
450 if (pdata->disable)
451 pdata->disable(bdev->dev);
452 }
453
454 static int gpio_keys_polled_probe(struct platform_device *pdev)
455 {
456 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
457 struct device *dev = &pdev->dev;
458 struct gpio_keys_polled_dev *bdev;
459 int error;
460 int i;
461
462 if (!pdata) {
463 pdata = gpio_keys_polled_get_devtree_pdata(dev);
464 if (IS_ERR(pdata))
465 return PTR_ERR(pdata);
466 if (!pdata) {
467 dev_err(dev, "missing platform data\n");
468 return -EINVAL;
469 }
470 }
471
472 if (!pdata->poll_interval) {
473 dev_err(dev, "missing poll_interval value\n");
474 error = -EINVAL;
475 goto err_free_pdata;
476 }
477
478 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
479 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
480 GFP_KERNEL);
481 if (!bdev) {
482 dev_err(dev, "no memory for private data\n");
483 return -ENOMEM;
484 }
485
486 for (i = 0; i < pdata->nbuttons; i++) {
487 struct gpio_keys_button *button = &pdata->buttons[i];
488 struct gpio_keys_button_data *bdata = &bdev->data[i];
489 unsigned int gpio = button->gpio;
490
491 if (button->wakeup) {
492 dev_err(dev, DRV_NAME " does not support wakeup\n");
493 error = -EINVAL;
494 goto err_free_gpio;
495 }
496
497 error = gpio_request(gpio,
498 button->desc ? button->desc : DRV_NAME);
499 if (error) {
500 dev_err(dev, "unable to claim gpio %u, err=%d\n",
501 gpio, error);
502 goto err_free_gpio;
503 }
504
505 error = gpio_direction_input(gpio);
506 if (error) {
507 dev_err(dev,
508 "unable to set direction on gpio %u, err=%d\n",
509 gpio, error);
510 goto err_free_gpio;
511 }
512
513 bdata->can_sleep = gpio_cansleep(gpio);
514 bdata->last_state = -1;
515 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
516 pdata->poll_interval);
517 }
518
519 bdev->dev = &pdev->dev;
520 bdev->pdata = pdata;
521 platform_set_drvdata(pdev, bdev);
522
523 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
524
525 gpio_keys_polled_open(bdev);
526
527 return 0;
528
529 err_free_gpio:
530 while (--i >= 0)
531 gpio_free(pdata->buttons[i].gpio);
532
533 kfree(bdev);
534 platform_set_drvdata(pdev, NULL);
535
536 err_free_pdata:
537 /* If we have no platform_data, we allocated pdata dynamically. */
538 if (!dev_get_platdata(&pdev->dev))
539 kfree(pdata);
540
541 return error;
542 }
543
544 static int gpio_keys_polled_remove(struct platform_device *pdev)
545 {
546 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
547 struct gpio_keys_platform_data *pdata = bdev->pdata;
548 int i = pdata->nbuttons;
549
550 gpio_keys_polled_close(bdev);
551
552 while (--i >= 0)
553 gpio_free(pdata->buttons[i].gpio);
554
555 kfree(bdev);
556 platform_set_drvdata(pdev, NULL);
557
558 return 0;
559 }
560
561 static struct platform_driver gpio_keys_polled_driver = {
562 .probe = gpio_keys_polled_probe,
563 .remove = gpio_keys_polled_remove,
564 .driver = {
565 .name = DRV_NAME,
566 .owner = THIS_MODULE,
567 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
568 },
569 };
570
571 static int __init gpio_keys_polled_init(void)
572 {
573 return platform_driver_register(&gpio_keys_polled_driver);
574 }
575
576 static void __exit gpio_keys_polled_exit(void)
577 {
578 platform_driver_unregister(&gpio_keys_polled_driver);
579 }
580
581 module_init(gpio_keys_polled_init);
582 module_exit(gpio_keys_polled_exit);
583
584 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
585 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
586 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
587 MODULE_LICENSE("GPL v2");
588 MODULE_ALIAS("platform:" DRV_NAME);