74c2ecaa2edba76a49cce168a2233ecef42d708b
[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_RESTART, "reset"),
94 BH_MAP(KEY_RFKILL, "rfkill"),
95 BH_MAP(KEY_WPS_BUTTON, "wps"),
96 };
97
98 /* -------------------------------------------------------------------------*/
99
100 static int bh_event_add_var(struct bh_event *event, int argv,
101 const char *format, ...)
102 {
103 static char buf[128];
104 char *s;
105 va_list args;
106 int len;
107
108 if (argv)
109 return 0;
110
111 va_start(args, format);
112 len = vsnprintf(buf, sizeof(buf), format, args);
113 va_end(args);
114
115 if (len >= sizeof(buf)) {
116 BH_ERR("buffer size too small\n");
117 WARN_ON(1);
118 return -ENOMEM;
119 }
120
121 s = skb_put(event->skb, len + 1);
122 strcpy(s, buf);
123
124 BH_DBG("added variable '%s'\n", s);
125
126 return 0;
127 }
128
129 static int button_hotplug_fill_event(struct bh_event *event)
130 {
131 int ret;
132
133 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
134 if (ret)
135 return ret;
136
137 ret = bh_event_add_var(event, 0, "PATH=%s",
138 "/sbin:/bin:/usr/sbin:/usr/bin");
139 if (ret)
140 return ret;
141
142 char *s;
143 switch (event->type) {
144 case EV_KEY:
145 s = "button";
146 break;
147 case EV_SW:
148 s = "switch";
149 break;
150 default:
151 s = "button";
152 break;
153 }
154
155 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", s);
156 if (ret)
157 return ret;
158
159 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
160 if (ret)
161 return ret;
162
163 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
164 if (ret)
165 return ret;
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 BH_ERR("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 BH_DBG("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 #ifdef CONFIG_HOTPLUG
231 static int button_get_index(unsigned int code)
232 {
233 int i;
234
235 for (i = 0; i < ARRAY_SIZE(button_map); i++)
236 if (button_map[i].code == code)
237 return i;
238
239 return -1;
240 }
241
242 static void button_hotplug_event(struct gpio_keys_button_data *data,
243 unsigned int type, unsigned int code, int value)
244 {
245 struct bh_priv *priv = &data->bh;
246 unsigned long seen = jiffies;
247 int btn;
248
249 BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
250
251 if ((type != EV_KEY) && (type != EV_SW))
252 return;
253
254 btn = button_get_index(code);
255 if (btn < 0)
256 return;
257
258 button_hotplug_create_event(button_map[btn].name, type,
259 (seen - priv->seen) / HZ, value);
260 priv->seen = seen;
261 }
262 #else
263 static void button_hotplug_event(struct gpio_keys_button_data *data,
264 unsigned int type, unsigned int code, int value)
265 {
266 }
267 #endif /* CONFIG_HOTPLUG */
268
269 struct gpio_keys_polled_dev {
270 struct delayed_work work;
271
272 struct device *dev;
273 struct gpio_keys_platform_data *pdata;
274 struct gpio_keys_button_data data[0];
275 };
276
277 static inline int gpio_button_get_value(struct gpio_keys_button *button,
278 struct gpio_keys_button_data *bdata)
279 {
280 if (bdata->can_sleep)
281 return !!gpio_get_value_cansleep(button->gpio);
282 else
283 return !!gpio_get_value(button->gpio);
284 }
285
286 static void gpio_keys_polled_check_state(struct gpio_keys_button *button,
287 struct gpio_keys_button_data *bdata)
288 {
289 int state;
290
291 state = gpio_button_get_value(button, bdata);
292
293 state = !!(state ^ button->active_low);
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 button_hotplug_event(bdata, type, button->code, state);
303 bdata->last_state = state;
304 }
305
306 bdata->count = 0;
307 }
308
309 static void gpio_keys_polled_queue_work(struct gpio_keys_polled_dev *bdev)
310 {
311 struct gpio_keys_platform_data *pdata = bdev->pdata;
312 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
313
314 if (delay >= HZ)
315 delay = round_jiffies_relative(delay);
316 schedule_delayed_work(&bdev->work, delay);
317 }
318
319 static void gpio_keys_polled_poll(struct work_struct *work)
320 {
321 struct gpio_keys_polled_dev *bdev =
322 container_of(work, struct gpio_keys_polled_dev, work.work);
323 struct gpio_keys_platform_data *pdata = bdev->pdata;
324 int i;
325
326 for (i = 0; i < bdev->pdata->nbuttons; i++) {
327 struct gpio_keys_button_data *bdata = &bdev->data[i];
328 gpio_keys_polled_check_state(&pdata->buttons[i], bdata);
329 }
330 gpio_keys_polled_queue_work(bdev);
331 }
332
333 static void gpio_keys_polled_open(struct gpio_keys_polled_dev *bdev)
334 {
335 struct gpio_keys_platform_data *pdata = bdev->pdata;
336 int i;
337
338 if (pdata->enable)
339 pdata->enable(bdev->dev);
340
341 /* report initial state of the buttons */
342 for (i = 0; i < pdata->nbuttons; i++)
343 gpio_keys_polled_check_state(&pdata->buttons[i], &bdev->data[i]);
344
345 gpio_keys_polled_queue_work(bdev);
346 }
347
348 #ifdef CONFIG_OF
349 static struct gpio_keys_platform_data *
350 gpio_keys_polled_get_devtree_pdata(struct device *dev)
351 {
352 struct device_node *node, *pp;
353 struct gpio_keys_platform_data *pdata;
354 struct gpio_keys_button *button;
355 int error;
356 int nbuttons;
357 int i;
358
359 node = dev->of_node;
360 if (!node)
361 return NULL;
362
363 nbuttons = of_get_child_count(node);
364 if (nbuttons == 0)
365 return NULL;
366
367 pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
368 GFP_KERNEL);
369 if (!pdata) {
370 error = -ENOMEM;
371 goto err_out;
372 }
373
374 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
375 pdata->nbuttons = nbuttons;
376
377 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
378 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
379
380 i = 0;
381 for_each_child_of_node(node, pp) {
382 enum of_gpio_flags flags;
383
384 if (!of_find_property(pp, "gpios", NULL)) {
385 pdata->nbuttons--;
386 dev_warn(dev, "Found button without gpios\n");
387 continue;
388 }
389
390 button = &pdata->buttons[i++];
391
392 button->gpio = of_get_gpio_flags(pp, 0, &flags);
393 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
394
395 if (of_property_read_u32(pp, "linux,code", &button->code)) {
396 dev_err(dev, "Button without keycode: 0x%x\n",
397 button->gpio);
398 error = -EINVAL;
399 goto err_free_pdata;
400 }
401
402 button->desc = of_get_property(pp, "label", NULL);
403
404 if (of_property_read_u32(pp, "linux,input-type", &button->type))
405 button->type = EV_KEY;
406
407 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
408
409 if (of_property_read_u32(pp, "debounce-interval",
410 &button->debounce_interval))
411 button->debounce_interval = 5;
412 }
413
414 if (pdata->nbuttons == 0) {
415 error = -EINVAL;
416 goto err_free_pdata;
417 }
418
419 return pdata;
420
421 err_free_pdata:
422 kfree(pdata);
423 err_out:
424 return ERR_PTR(error);
425 }
426
427 static struct of_device_id gpio_keys_polled_of_match[] = {
428 { .compatible = "gpio-keys-polled", },
429 { },
430 };
431 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
432
433 #else
434
435 static inline struct gpio_keys_platform_data *
436 gpio_keys_polled_get_devtree_pdata(struct device *dev)
437 {
438 return NULL;
439 }
440 #endif
441
442 static void gpio_keys_polled_close(struct gpio_keys_polled_dev *bdev)
443 {
444 struct gpio_keys_platform_data *pdata = bdev->pdata;
445
446 cancel_delayed_work_sync(&bdev->work);
447
448 if (pdata->disable)
449 pdata->disable(bdev->dev);
450 }
451
452 static int gpio_keys_polled_probe(struct platform_device *pdev)
453 {
454 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
455 struct device *dev = &pdev->dev;
456 struct gpio_keys_polled_dev *bdev;
457 int error;
458 int i;
459
460 if (!pdata) {
461 pdata = gpio_keys_polled_get_devtree_pdata(dev);
462 if (IS_ERR(pdata))
463 return PTR_ERR(pdata);
464 if (!pdata) {
465 dev_err(dev, "missing platform data\n");
466 return -EINVAL;
467 }
468 }
469
470 if (!pdata->poll_interval) {
471 dev_err(dev, "missing poll_interval value\n");
472 error = -EINVAL;
473 goto err_free_pdata;
474 }
475
476 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
477 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
478 GFP_KERNEL);
479 if (!bdev) {
480 dev_err(dev, "no memory for private data\n");
481 return -ENOMEM;
482 }
483
484 for (i = 0; i < pdata->nbuttons; i++) {
485 struct gpio_keys_button *button = &pdata->buttons[i];
486 struct gpio_keys_button_data *bdata = &bdev->data[i];
487 unsigned int gpio = button->gpio;
488
489 if (button->wakeup) {
490 dev_err(dev, DRV_NAME " does not support wakeup\n");
491 error = -EINVAL;
492 goto err_free_gpio;
493 }
494
495 error = gpio_request(gpio,
496 button->desc ? button->desc : DRV_NAME);
497 if (error) {
498 dev_err(dev, "unable to claim gpio %u, err=%d\n",
499 gpio, error);
500 goto err_free_gpio;
501 }
502
503 error = gpio_direction_input(gpio);
504 if (error) {
505 dev_err(dev,
506 "unable to set direction on gpio %u, err=%d\n",
507 gpio, error);
508 goto err_free_gpio;
509 }
510
511 bdata->can_sleep = gpio_cansleep(gpio);
512 bdata->last_state = gpio_button_get_value(button, bdata);
513 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
514 pdata->poll_interval);
515 }
516
517 bdev->dev = &pdev->dev;
518 bdev->pdata = pdata;
519 platform_set_drvdata(pdev, bdev);
520
521 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
522
523 gpio_keys_polled_open(bdev);
524
525 return 0;
526
527 err_free_gpio:
528 while (--i >= 0)
529 gpio_free(pdata->buttons[i].gpio);
530
531 kfree(bdev);
532 platform_set_drvdata(pdev, NULL);
533
534 err_free_pdata:
535 /* If we have no platform_data, we allocated pdata dynamically. */
536 if (!dev_get_platdata(&pdev->dev))
537 kfree(pdata);
538
539 return error;
540 }
541
542 static int gpio_keys_polled_remove(struct platform_device *pdev)
543 {
544 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
545 struct gpio_keys_platform_data *pdata = bdev->pdata;
546 int i = pdata->nbuttons;
547
548 gpio_keys_polled_close(bdev);
549
550 while (--i >= 0)
551 gpio_free(pdata->buttons[i].gpio);
552
553 kfree(bdev);
554 platform_set_drvdata(pdev, NULL);
555
556 return 0;
557 }
558
559 static struct platform_driver gpio_keys_polled_driver = {
560 .probe = gpio_keys_polled_probe,
561 .remove = gpio_keys_polled_remove,
562 .driver = {
563 .name = DRV_NAME,
564 .owner = THIS_MODULE,
565 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
566 },
567 };
568
569 static int __init gpio_keys_polled_init(void)
570 {
571 return platform_driver_register(&gpio_keys_polled_driver);
572 }
573
574 static void __exit gpio_keys_polled_exit(void)
575 {
576 platform_driver_unregister(&gpio_keys_polled_driver);
577 }
578
579 module_init(gpio_keys_polled_init);
580 module_exit(gpio_keys_polled_exit);
581
582 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
583 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
584 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
585 MODULE_LICENSE("GPL v2");
586 MODULE_ALIAS("platform:" DRV_NAME);