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)
134 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
138 ret = bh_event_add_var(event, 0, "PATH=%s",
139 "/sbin:/bin:/usr/sbin:/usr/bin");
143 switch (event->type) {
153 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", s);
157 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
161 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
165 ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
169 ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
174 static void button_hotplug_work(struct work_struct *work)
176 struct bh_event *event = container_of(work, struct bh_event, work);
179 event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
183 ret = bh_event_add_var(event, 0, "%s@", event->action);
187 ret = button_hotplug_fill_event(event);
191 NETLINK_CB(event->skb).dst_group = 1;
192 broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
196 BH_ERR("work error %d\n", ret);
197 kfree_skb(event->skb);
203 static int button_hotplug_create_event(const char *name, unsigned int type,
204 unsigned long seen, int pressed)
206 struct bh_event *event;
208 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
209 name, seen, pressed);
211 event = kzalloc(sizeof(*event), GFP_KERNEL);
218 event->action = pressed ? "pressed" : "released";
220 INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
221 schedule_work(&event->work);
226 /* -------------------------------------------------------------------------*/
228 #ifdef CONFIG_HOTPLUG
229 static int button_get_index(unsigned int code)
233 for (i = 0; i < ARRAY_SIZE(button_map); i++)
234 if (button_map[i].code == code)
240 static void button_hotplug_event(struct gpio_keys_button_data *data,
241 unsigned int type, unsigned int code, int value)
243 struct bh_priv *priv = &data->bh;
244 unsigned long seen = jiffies;
247 BH_DBG("event type=%u, code=%u, value=%d\n", type, code, value);
249 if ((type != EV_KEY) && (type != EV_SW))
252 btn = button_get_index(code);
256 button_hotplug_create_event(button_map[btn].name, type,
257 (seen - priv->seen) / HZ, value);
261 static void button_hotplug_event(struct gpio_keys_button_data *data,
262 unsigned int type, unsigned int code, int value)
265 #endif /* CONFIG_HOTPLUG */
267 struct gpio_keys_polled_dev {
268 struct delayed_work work;
271 struct gpio_keys_platform_data *pdata;
272 struct gpio_keys_button_data data[0];
275 static int gpio_button_get_value(struct gpio_keys_button *button,
276 struct gpio_keys_button_data *bdata)
280 if (bdata->can_sleep)
281 val = !!gpio_get_value_cansleep(button->gpio);
283 val = !!gpio_get_value(button->gpio);
285 return val ^ button->active_low;
288 static void gpio_keys_polled_check_state(struct gpio_keys_button *button,
289 struct gpio_keys_button_data *bdata)
291 int state = gpio_button_get_value(button, bdata);
293 if (state != bdata->last_state) {
294 unsigned int type = button->type ?: EV_KEY;
296 if (bdata->count < bdata->threshold) {
301 if (bdata->last_state != -1)
302 button_hotplug_event(bdata, type, button->code, state);
304 bdata->last_state = state;
310 static void gpio_keys_polled_queue_work(struct gpio_keys_polled_dev *bdev)
312 struct gpio_keys_platform_data *pdata = bdev->pdata;
313 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
316 delay = round_jiffies_relative(delay);
317 schedule_delayed_work(&bdev->work, delay);
320 static void gpio_keys_polled_poll(struct work_struct *work)
322 struct gpio_keys_polled_dev *bdev =
323 container_of(work, struct gpio_keys_polled_dev, work.work);
324 struct gpio_keys_platform_data *pdata = bdev->pdata;
327 for (i = 0; i < bdev->pdata->nbuttons; i++) {
328 struct gpio_keys_button_data *bdata = &bdev->data[i];
329 gpio_keys_polled_check_state(&pdata->buttons[i], bdata);
331 gpio_keys_polled_queue_work(bdev);
334 static void gpio_keys_polled_open(struct gpio_keys_polled_dev *bdev)
336 struct gpio_keys_platform_data *pdata = bdev->pdata;
340 pdata->enable(bdev->dev);
342 /* report initial state of the buttons */
343 for (i = 0; i < pdata->nbuttons; i++)
344 gpio_keys_polled_check_state(&pdata->buttons[i], &bdev->data[i]);
346 gpio_keys_polled_queue_work(bdev);
350 static struct gpio_keys_platform_data *
351 gpio_keys_polled_get_devtree_pdata(struct device *dev)
353 struct device_node *node, *pp;
354 struct gpio_keys_platform_data *pdata;
355 struct gpio_keys_button *button;
364 nbuttons = of_get_child_count(node);
368 pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
375 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
376 pdata->nbuttons = nbuttons;
378 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
379 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
382 for_each_child_of_node(node, pp) {
383 enum of_gpio_flags flags;
385 if (!of_find_property(pp, "gpios", NULL)) {
387 dev_warn(dev, "Found button without gpios\n");
391 button = &pdata->buttons[i++];
393 button->gpio = of_get_gpio_flags(pp, 0, &flags);
394 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
396 if (of_property_read_u32(pp, "linux,code", &button->code)) {
397 dev_err(dev, "Button without keycode: 0x%x\n",
403 button->desc = of_get_property(pp, "label", NULL);
405 if (of_property_read_u32(pp, "linux,input-type", &button->type))
406 button->type = EV_KEY;
408 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
410 if (of_property_read_u32(pp, "debounce-interval",
411 &button->debounce_interval))
412 button->debounce_interval = 5;
415 if (pdata->nbuttons == 0) {
425 return ERR_PTR(error);
428 static struct of_device_id gpio_keys_polled_of_match[] = {
429 { .compatible = "gpio-keys-polled", },
432 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
436 static inline struct gpio_keys_platform_data *
437 gpio_keys_polled_get_devtree_pdata(struct device *dev)
443 static void gpio_keys_polled_close(struct gpio_keys_polled_dev *bdev)
445 struct gpio_keys_platform_data *pdata = bdev->pdata;
447 cancel_delayed_work_sync(&bdev->work);
450 pdata->disable(bdev->dev);
453 static int gpio_keys_polled_probe(struct platform_device *pdev)
455 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
456 struct device *dev = &pdev->dev;
457 struct gpio_keys_polled_dev *bdev;
462 pdata = gpio_keys_polled_get_devtree_pdata(dev);
464 return PTR_ERR(pdata);
466 dev_err(dev, "missing platform data\n");
471 if (!pdata->poll_interval) {
472 dev_err(dev, "missing poll_interval value\n");
477 bdev = kzalloc(sizeof(struct gpio_keys_polled_dev) +
478 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
481 dev_err(dev, "no memory for private data\n");
485 for (i = 0; i < pdata->nbuttons; i++) {
486 struct gpio_keys_button *button = &pdata->buttons[i];
487 struct gpio_keys_button_data *bdata = &bdev->data[i];
488 unsigned int gpio = button->gpio;
490 if (button->wakeup) {
491 dev_err(dev, DRV_NAME " does not support wakeup\n");
496 error = gpio_request(gpio,
497 button->desc ? button->desc : DRV_NAME);
499 dev_err(dev, "unable to claim gpio %u, err=%d\n",
504 error = gpio_direction_input(gpio);
507 "unable to set direction on gpio %u, err=%d\n",
512 bdata->can_sleep = gpio_cansleep(gpio);
513 bdata->last_state = -1;
514 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
515 pdata->poll_interval);
518 bdev->dev = &pdev->dev;
520 platform_set_drvdata(pdev, bdev);
522 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
524 gpio_keys_polled_open(bdev);
530 gpio_free(pdata->buttons[i].gpio);
533 platform_set_drvdata(pdev, NULL);
536 /* If we have no platform_data, we allocated pdata dynamically. */
537 if (!dev_get_platdata(&pdev->dev))
543 static int gpio_keys_polled_remove(struct platform_device *pdev)
545 struct gpio_keys_polled_dev *bdev = platform_get_drvdata(pdev);
546 struct gpio_keys_platform_data *pdata = bdev->pdata;
547 int i = pdata->nbuttons;
549 gpio_keys_polled_close(bdev);
552 gpio_free(pdata->buttons[i].gpio);
555 platform_set_drvdata(pdev, NULL);
560 static struct platform_driver gpio_keys_polled_driver = {
561 .probe = gpio_keys_polled_probe,
562 .remove = gpio_keys_polled_remove,
565 .owner = THIS_MODULE,
566 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
570 static int __init gpio_keys_polled_init(void)
572 return platform_driver_register(&gpio_keys_polled_driver);
575 static void __exit gpio_keys_polled_exit(void)
577 platform_driver_unregister(&gpio_keys_polled_driver);
580 module_init(gpio_keys_polled_init);
581 module_exit(gpio_keys_polled_exit);
583 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
584 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
585 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
586 MODULE_LICENSE("GPL v2");
587 MODULE_ALIAS("platform:" DRV_NAME);