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/of_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 )
57 struct work_struct work;
65 struct gpio_keys_button_data {
66 struct delayed_work work;
74 extern u64 uevent_next_seqnum(void);
76 #define BH_MAP(_code, _name) \
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"),
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");
143 switch (event->type) {
155 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", s);
159 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
163 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
167 ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
171 ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
176 static void button_hotplug_work(struct work_struct *work)
178 struct bh_event *event = container_of(work, struct bh_event, work);
181 event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
185 ret = bh_event_add_var(event, 0, "%s@", event->action);
189 ret = button_hotplug_fill_event(event);
193 NETLINK_CB(event->skb).dst_group = 1;
194 broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
198 BH_ERR("work error %d\n", ret);
199 kfree_skb(event->skb);
205 static int button_hotplug_create_event(const char *name, unsigned int type,
206 unsigned long seen, int pressed)
208 struct bh_event *event;
210 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
211 name, seen, pressed);
213 event = kzalloc(sizeof(*event), GFP_KERNEL);
220 event->action = pressed ? "pressed" : "released";
222 INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
223 schedule_work(&event->work);
228 /* -------------------------------------------------------------------------*/
230 #ifdef CONFIG_HOTPLUG
231 static int button_get_index(unsigned int code)
235 for (i = 0; i < ARRAY_SIZE(button_map); i++)
236 if (button_map[i].code == code)
242 static void button_hotplug_event(struct gpio_keys_button_data *data,
243 unsigned int type, unsigned int code, int value)
245 struct bh_priv *priv = &data->bh;
246 unsigned long seen = jiffies;
249 BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
251 if ((type != EV_KEY) && (type != EV_SW))
254 btn = button_get_index(code);
258 button_hotplug_create_event(button_map[btn].name, type,
259 (seen - priv->seen) / HZ, value);
263 static void button_hotplug_event(struct gpio_keys_button_data *data,
264 unsigned int type, unsigned int code, int value)
267 #endif /* CONFIG_HOTPLUG */
269 struct gpio_keys_polled_dev {
270 struct delayed_work work;
273 struct gpio_keys_platform_data *pdata;
274 struct gpio_keys_button_data data[0];
277 static inline int gpio_button_get_value(struct gpio_keys_button *button,
278 struct gpio_keys_button_data *bdata)
280 if (bdata->can_sleep)
281 return !!gpio_get_value_cansleep(button->gpio);
283 return !!gpio_get_value(button->gpio);
286 static void gpio_keys_polled_check_state(struct gpio_keys_button *button,
287 struct gpio_keys_button_data *bdata)
291 if (bdata->can_sleep)
292 state = !!gpio_get_value_cansleep(button->gpio);
294 state = !!gpio_get_value(button->gpio);
296 state = !!(state ^ button->active_low);
297 if (state != bdata->last_state) {
298 unsigned int type = button->type ?: EV_KEY;
300 if (bdata->count < bdata->threshold) {
305 button_hotplug_event(bdata, type, button->code, state);
306 bdata->last_state = state;
312 static void gpio_keys_polled_queue_work(struct gpio_keys_polled_dev *bdev)
314 struct gpio_keys_platform_data *pdata = bdev->pdata;
315 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
318 delay = round_jiffies_relative(delay);
319 schedule_delayed_work(&bdev->work, delay);
322 static void gpio_keys_polled_poll(struct work_struct *work)
324 struct gpio_keys_polled_dev *bdev =
325 container_of(work, struct gpio_keys_polled_dev, work.work);
326 struct gpio_keys_platform_data *pdata = bdev->pdata;
329 for (i = 0; i < bdev->pdata->nbuttons; i++) {
330 struct gpio_keys_button_data *bdata = &bdev->data[i];
331 gpio_keys_polled_check_state(&pdata->buttons[i], bdata);
333 gpio_keys_polled_queue_work(bdev);
336 static void gpio_keys_polled_open(struct gpio_keys_polled_dev *bdev)
338 struct gpio_keys_platform_data *pdata = bdev->pdata;
342 pdata->enable(bdev->dev);
344 /* report initial state of the buttons */
345 for (i = 0; i < pdata->nbuttons; i++)
346 gpio_keys_polled_check_state(&pdata->buttons[i], &bdev->data[i]);
348 gpio_keys_polled_queue_work(bdev);
352 static struct gpio_keys_platform_data *
353 gpio_keys_polled_get_devtree_pdata(struct device *dev)
355 struct device_node *node, *pp;
356 struct gpio_keys_platform_data *pdata;
357 struct gpio_keys_button *button;
366 nbuttons = of_get_child_count(node);
370 pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
377 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
378 pdata->nbuttons = nbuttons;
380 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
381 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
384 for_each_child_of_node(node, pp) {
385 enum of_gpio_flags flags;
387 if (!of_find_property(pp, "gpios", NULL)) {
389 dev_warn(dev, "Found button without gpios\n");
393 button = &pdata->buttons[i++];
395 button->gpio = of_get_gpio_flags(pp, 0, &flags);
396 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
398 if (of_property_read_u32(pp, "linux,code", &button->code)) {
399 dev_err(dev, "Button without keycode: 0x%x\n",
405 button->desc = of_get_property(pp, "label", NULL);
407 if (of_property_read_u32(pp, "linux,input-type", &button->type))
408 button->type = EV_KEY;
410 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
412 if (of_property_read_u32(pp, "debounce-interval",
413 &button->debounce_interval))
414 button->debounce_interval = 5;
417 if (pdata->nbuttons == 0) {
427 return ERR_PTR(error);
430 static struct of_device_id gpio_keys_polled_of_match[] = {
431 { .compatible = "gpio-keys-polled", },
434 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
438 static inline struct gpio_keys_platform_data *
439 gpio_keys_polled_get_devtree_pdata(struct device *dev)
445 static void gpio_keys_polled_close(struct gpio_keys_polled_dev *bdev)
447 struct gpio_keys_platform_data *pdata = bdev->pdata;
449 cancel_delayed_work_sync(&bdev->work);
452 pdata->disable(bdev->dev);
455 static int gpio_keys_polled_probe(struct platform_device *pdev)
457 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
458 struct device *dev = &pdev->dev;
459 struct gpio_keys_polled_dev *bdev;
464 pdata = gpio_keys_polled_get_devtree_pdata(dev);
466 return PTR_ERR(pdata);
468 dev_err(dev, "missing platform data\n");
473 if (!pdata->poll_interval) {
474 dev_err(dev, "missing poll_interval value\n");
479 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
480 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
483 dev_err(dev, "no memory for private data\n");
487 for (i = 0; i < pdata->nbuttons; i++) {
488 struct gpio_keys_button *button = &pdata->buttons[i];
489 struct gpio_keys_button_data *bdata = &bdev->data[i];
490 unsigned int gpio = button->gpio;
492 if (button->wakeup) {
493 dev_err(dev, DRV_NAME " does not support wakeup\n");
498 error = gpio_request(gpio,
499 button->desc ? button->desc : DRV_NAME);
501 dev_err(dev, "unable to claim gpio %u, err=%d\n",
506 error = gpio_direction_input(gpio);
509 "unable to set direction on gpio %u, err=%d\n",
514 bdata->can_sleep = gpio_cansleep(gpio);
515 bdata->last_state = 0;
516 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
517 pdata->poll_interval);
520 bdev->dev = &pdev->dev;
522 platform_set_drvdata(pdev, bdev);
524 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
526 gpio_keys_polled_open(bdev);
532 gpio_free(pdata->buttons[i].gpio);
535 platform_set_drvdata(pdev, NULL);
538 /* If we have no platform_data, we allocated pdata dynamically. */
539 if (!dev_get_platdata(&pdev->dev))
545 static int gpio_keys_polled_remove(struct platform_device *pdev)
547 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
548 struct gpio_keys_platform_data *pdata = bdev->pdata;
549 int i = pdata->nbuttons;
551 gpio_keys_polled_close(bdev);
554 gpio_free(pdata->buttons[i].gpio);
557 platform_set_drvdata(pdev, NULL);
562 static struct platform_driver gpio_keys_polled_driver = {
563 .probe = gpio_keys_polled_probe,
564 .remove = gpio_keys_polled_remove,
567 .owner = THIS_MODULE,
568 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
572 static int __init gpio_keys_polled_init(void)
574 return platform_driver_register(&gpio_keys_polled_driver);
577 static void __exit gpio_keys_polled_exit(void)
579 platform_driver_unregister(&gpio_keys_polled_driver);
582 module_init(gpio_keys_polled_init);
583 module_exit(gpio_keys_polled_exit);
585 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
586 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
587 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
588 MODULE_LICENSE("GPL v2");
589 MODULE_ALIAS("platform:" DRV_NAME);