2 * GPIO Button Hotplug driver
4 * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
5 * Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
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>
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.
17 #include <linux/module.h>
18 #include <linux/version.h>
19 #include <linux/kmod.h>
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/gpio.h>
28 #include <linux/gpio_keys.h>
30 #define DRV_NAME "gpio-keys-polled"
32 #define BH_SKB_SIZE 2048
34 #define PFX DRV_NAME ": "
39 #define BH_DBG(fmt, args...) printk(KERN_DEBUG "%s: " fmt, DRV_NAME, ##args )
41 #define BH_DBG(fmt, args...) do {} while (0)
44 #define BH_ERR(fmt, args...) printk(KERN_ERR "%s: " fmt, DRV_NAME, ##args )
56 struct work_struct work;
64 struct gpio_keys_button_data {
65 struct delayed_work work;
73 extern u64 uevent_next_seqnum(void);
75 #define BH_MAP(_code, _name) \
81 static struct bh_map button_map[] = {
82 BH_MAP(BTN_0, "BTN_0"),
83 BH_MAP(BTN_1, "BTN_1"),
84 BH_MAP(BTN_2, "BTN_2"),
85 BH_MAP(BTN_3, "BTN_3"),
86 BH_MAP(BTN_4, "BTN_4"),
87 BH_MAP(BTN_5, "BTN_5"),
88 BH_MAP(BTN_6, "BTN_6"),
89 BH_MAP(BTN_7, "BTN_7"),
90 BH_MAP(BTN_8, "BTN_8"),
91 BH_MAP(BTN_9, "BTN_9"),
92 BH_MAP(KEY_RESTART, "reset"),
94 BH_MAP(KEY_WPS_BUTTON, "wps"),
95 #endif /* KEY_WPS_BUTTON */
98 /* -------------------------------------------------------------------------*/
100 static int bh_event_add_var(struct bh_event *event, int argv,
101 const char *format, ...)
103 static char buf[128];
111 va_start(args, format);
112 len = vsnprintf(buf, sizeof(buf), format, args);
115 if (len >= sizeof(buf)) {
116 BH_ERR("buffer size too small\n");
121 s = skb_put(event->skb, len + 1);
124 BH_DBG("added variable '%s'\n", s);
129 static int button_hotplug_fill_event(struct bh_event *event)
133 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
137 ret = bh_event_add_var(event, 0, "PATH=%s",
138 "/sbin:/bin:/usr/sbin:/usr/bin");
142 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
146 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
150 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
154 ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
158 ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
163 static void button_hotplug_work(struct work_struct *work)
165 struct bh_event *event = container_of(work, struct bh_event, work);
168 event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
172 ret = bh_event_add_var(event, 0, "%s@", event->action);
176 ret = button_hotplug_fill_event(event);
180 NETLINK_CB(event->skb).dst_group = 1;
181 broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
185 BH_ERR("work error %d\n", ret);
186 kfree_skb(event->skb);
192 static int button_hotplug_create_event(const char *name, unsigned long seen,
195 struct bh_event *event;
197 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
198 name, seen, pressed);
200 event = kzalloc(sizeof(*event), GFP_KERNEL);
206 event->action = pressed ? "pressed" : "released";
208 INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
209 schedule_work(&event->work);
214 /* -------------------------------------------------------------------------*/
216 #ifdef CONFIG_HOTPLUG
217 static int button_get_index(unsigned int code)
221 for (i = 0; i < ARRAY_SIZE(button_map); i++)
222 if (button_map[i].code == code)
227 static void button_hotplug_event(struct gpio_keys_button_data *data,
228 unsigned int type, unsigned int code, int value)
230 struct bh_priv *priv = &data->bh;
231 unsigned long seen = jiffies;
234 BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
239 btn = button_get_index(code);
243 button_hotplug_create_event(button_map[btn].name,
244 (seen - priv->seen) / HZ, value);
248 static void button_hotplug_event(struct gpio_keys_button_data *data,
249 unsigned int type, unsigned int code, int value)
252 #endif /* CONFIG_HOTPLUG */
254 struct gpio_keys_polled_dev {
255 struct delayed_work work;
258 struct gpio_keys_platform_data *pdata;
259 struct gpio_keys_button_data data[0];
262 static void gpio_keys_polled_check_state(struct gpio_keys_button *button,
263 struct gpio_keys_button_data *bdata)
267 if (bdata->can_sleep)
268 state = !!gpio_get_value_cansleep(button->gpio);
270 state = !!gpio_get_value(button->gpio);
272 state = !!(state ^ button->active_low);
273 if (state != bdata->last_state) {
274 unsigned int type = button->type ?: EV_KEY;
276 button_hotplug_event(bdata, type, button->code, state);
278 bdata->last_state = state;
282 static void gpio_keys_polled_queue_work(struct gpio_keys_polled_dev *bdev)
284 struct gpio_keys_platform_data *pdata = bdev->pdata;
285 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
288 delay = round_jiffies_relative(delay);
289 schedule_delayed_work(&bdev->work, delay);
292 static void gpio_keys_polled_poll(struct work_struct *work)
294 struct gpio_keys_polled_dev *bdev =
295 container_of(work, struct gpio_keys_polled_dev, work.work);
296 struct gpio_keys_platform_data *pdata = bdev->pdata;
299 for (i = 0; i < bdev->pdata->nbuttons; i++) {
300 struct gpio_keys_button_data *bdata = &bdev->data[i];
302 if (bdata->count < bdata->threshold)
305 gpio_keys_polled_check_state(&pdata->buttons[i], bdata);
307 gpio_keys_polled_queue_work(bdev);
310 static void __devinit gpio_keys_polled_open(struct gpio_keys_polled_dev *bdev)
312 struct gpio_keys_platform_data *pdata = bdev->pdata;
316 pdata->enable(bdev->dev);
318 /* report initial state of the buttons */
319 for (i = 0; i < pdata->nbuttons; i++)
320 gpio_keys_polled_check_state(&pdata->buttons[i], &bdev->data[i]);
322 gpio_keys_polled_queue_work(bdev);
325 static void __devexit gpio_keys_polled_close(struct gpio_keys_polled_dev *bdev)
327 struct gpio_keys_platform_data *pdata = bdev->pdata;
329 cancel_delayed_work_sync(&bdev->work);
332 pdata->disable(bdev->dev);
335 static int __devinit gpio_keys_polled_probe(struct platform_device *pdev)
337 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
338 struct device *dev = &pdev->dev;
339 struct gpio_keys_polled_dev *bdev;
343 if (!pdata || !pdata->poll_interval)
346 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
347 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
350 dev_err(dev, "no memory for private data\n");
354 for (i = 0; i < pdata->nbuttons; i++) {
355 struct gpio_keys_button *button = &pdata->buttons[i];
356 struct gpio_keys_button_data *bdata = &bdev->data[i];
357 unsigned int gpio = button->gpio;
359 if (button->wakeup) {
360 dev_err(dev, DRV_NAME " does not support wakeup\n");
365 error = gpio_request(gpio,
366 button->desc ? button->desc : DRV_NAME);
368 dev_err(dev, "unable to claim gpio %u, err=%d\n",
373 error = gpio_direction_input(gpio);
376 "unable to set direction on gpio %u, err=%d\n",
381 bdata->can_sleep = gpio_cansleep(gpio);
382 bdata->last_state = 0;
383 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
384 pdata->poll_interval);
387 bdev->dev = &pdev->dev;
389 platform_set_drvdata(pdev, bdev);
391 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
393 gpio_keys_polled_open(bdev);
399 gpio_free(pdata->buttons[i].gpio);
402 platform_set_drvdata(pdev, NULL);
407 static int __devexit gpio_keys_polled_remove(struct platform_device *pdev)
409 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
410 struct gpio_keys_platform_data *pdata = bdev->pdata;
411 int i = pdata->nbuttons;
413 gpio_keys_polled_close(bdev);
416 gpio_free(pdata->buttons[i].gpio);
419 platform_set_drvdata(pdev, NULL);
424 static struct platform_driver gpio_keys_polled_driver = {
425 .probe = gpio_keys_polled_probe,
426 .remove = __devexit_p(gpio_keys_polled_remove),
429 .owner = THIS_MODULE,
433 static int __init gpio_keys_polled_init(void)
435 return platform_driver_register(&gpio_keys_polled_driver);
438 static void __exit gpio_keys_polled_exit(void)
440 platform_driver_unregister(&gpio_keys_polled_driver);
443 module_init(gpio_keys_polled_init);
444 module_exit(gpio_keys_polled_exit);
446 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
447 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
448 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
449 MODULE_LICENSE("GPL v2");
450 MODULE_ALIAS("platform:" DRV_NAME);