2 * GPIO Button Hotplug driver
4 * Copyright (C) 2012 Felix Fietkau <nbd@nbd.name>
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@nbd.name>
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/interrupt.h>
27 #include <linux/platform_device.h>
28 #include <linux/of_gpio.h>
29 #include <linux/gpio_keys.h>
31 #define DRV_NAME "gpio-keys"
33 #define BH_SKB_SIZE 2048
35 #define PFX DRV_NAME ": "
40 #define BH_DBG(fmt, args...) printk(KERN_DEBUG "%s: " fmt, DRV_NAME, ##args )
42 #define BH_DBG(fmt, args...) do {} while (0)
45 #define BH_ERR(fmt, args...) printk(KERN_ERR "%s: " fmt, DRV_NAME, ##args )
58 struct work_struct work;
66 struct gpio_keys_button_data {
67 struct delayed_work work;
73 struct gpio_keys_button *b;
76 extern u64 uevent_next_seqnum(void);
78 #define BH_MAP(_code, _name) \
84 static struct bh_map button_map[] = {
85 BH_MAP(BTN_0, "BTN_0"),
86 BH_MAP(BTN_1, "BTN_1"),
87 BH_MAP(BTN_2, "BTN_2"),
88 BH_MAP(BTN_3, "BTN_3"),
89 BH_MAP(BTN_4, "BTN_4"),
90 BH_MAP(BTN_5, "BTN_5"),
91 BH_MAP(BTN_6, "BTN_6"),
92 BH_MAP(BTN_7, "BTN_7"),
93 BH_MAP(BTN_8, "BTN_8"),
94 BH_MAP(BTN_9, "BTN_9"),
95 BH_MAP(KEY_BRIGHTNESS_ZERO, "brightness_zero"),
96 BH_MAP(KEY_CONFIG, "config"),
97 BH_MAP(KEY_COPY, "copy"),
98 BH_MAP(KEY_EJECTCD, "eject"),
99 BH_MAP(KEY_HELP, "help"),
100 BH_MAP(KEY_LIGHTS_TOGGLE, "lights_toggle"),
101 BH_MAP(KEY_PHONE, "phone"),
102 BH_MAP(KEY_POWER, "power"),
103 BH_MAP(KEY_RESTART, "reset"),
104 BH_MAP(KEY_RFKILL, "rfkill"),
105 BH_MAP(KEY_VIDEO, "video"),
106 BH_MAP(KEY_WIMAX, "wwan"),
107 BH_MAP(KEY_WLAN, "wlan"),
108 BH_MAP(KEY_WPS_BUTTON, "wps"),
111 /* -------------------------------------------------------------------------*/
113 static __printf(3, 4)
114 int bh_event_add_var(struct bh_event *event, int argv, const char *format, ...)
116 static char buf[128];
124 va_start(args, format);
125 len = vsnprintf(buf, sizeof(buf), format, args);
128 if (len >= sizeof(buf)) {
129 WARN(1, "buffer size too small");
133 s = skb_put(event->skb, len + 1);
136 BH_DBG("added variable '%s'\n", s);
141 static int button_hotplug_fill_event(struct bh_event *event)
145 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
149 ret = bh_event_add_var(event, 0, "PATH=%s",
150 "/sbin:/bin:/usr/sbin:/usr/bin");
154 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
158 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
162 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
166 if (event->type == EV_SW) {
167 ret = bh_event_add_var(event, 0, "TYPE=%s", "switch");
172 ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
176 ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
181 static void button_hotplug_work(struct work_struct *work)
183 struct bh_event *event = container_of(work, struct bh_event, work);
186 event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
190 ret = bh_event_add_var(event, 0, "%s@", event->action);
194 ret = button_hotplug_fill_event(event);
198 NETLINK_CB(event->skb).dst_group = 1;
199 broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
203 BH_ERR("work error %d\n", ret);
204 kfree_skb(event->skb);
210 static int button_hotplug_create_event(const char *name, unsigned int type,
211 unsigned long seen, int pressed)
213 struct bh_event *event;
215 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
216 name, seen, pressed);
218 event = kzalloc(sizeof(*event), GFP_KERNEL);
225 event->action = pressed ? "pressed" : "released";
227 INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
228 schedule_work(&event->work);
233 /* -------------------------------------------------------------------------*/
235 static int button_get_index(unsigned int code)
239 for (i = 0; i < ARRAY_SIZE(button_map); i++)
240 if (button_map[i].code == code)
246 static void button_hotplug_event(struct gpio_keys_button_data *data,
247 unsigned int type, int value)
249 struct bh_priv *priv = &data->bh;
250 unsigned long seen = jiffies;
253 BH_DBG("event type=%u, code=%u, value=%d\n", type, data->b->code, value);
255 if ((type != EV_KEY) && (type != EV_SW))
258 btn = button_get_index(data->b->code);
262 button_hotplug_create_event(button_map[btn].name, type,
263 (seen - priv->seen) / HZ, value);
267 struct gpio_keys_button_dev {
269 struct delayed_work work;
272 struct gpio_keys_platform_data *pdata;
273 struct gpio_keys_button_data data[0];
276 static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
280 if (bdata->can_sleep)
281 val = !!gpio_get_value_cansleep(bdata->b->gpio);
283 val = !!gpio_get_value(bdata->b->gpio);
285 return val ^ bdata->b->active_low;
288 static void gpio_keys_polled_check_state(struct gpio_keys_button_data *bdata)
290 int state = gpio_button_get_value(bdata);
292 if (state != bdata->last_state) {
293 unsigned int type = bdata->b->type ?: EV_KEY;
295 if (bdata->count < bdata->threshold) {
300 if ((bdata->last_state != -1) || (type == EV_SW))
301 button_hotplug_event(bdata, type, state);
303 bdata->last_state = state;
309 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
311 struct gpio_keys_platform_data *pdata = bdev->pdata;
312 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
315 delay = round_jiffies_relative(delay);
316 schedule_delayed_work(&bdev->work, delay);
319 static void gpio_keys_polled_poll(struct work_struct *work)
321 struct gpio_keys_button_dev *bdev =
322 container_of(work, struct gpio_keys_button_dev, work.work);
325 for (i = 0; i < bdev->pdata->nbuttons; i++) {
326 struct gpio_keys_button_data *bdata = &bdev->data[i];
327 gpio_keys_polled_check_state(bdata);
329 gpio_keys_polled_queue_work(bdev);
332 static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev)
334 struct gpio_keys_platform_data *pdata = bdev->pdata;
336 cancel_delayed_work_sync(&bdev->work);
339 pdata->disable(bdev->dev);
342 static irqreturn_t button_handle_irq(int irq, void *_bdata)
344 struct gpio_keys_button_data *bdata = (struct gpio_keys_button_data *) _bdata;
346 button_hotplug_event(bdata, bdata->b->type ?: EV_KEY, gpio_button_get_value(bdata));
352 static struct gpio_keys_platform_data *
353 gpio_keys_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 = devm_kzalloc(dev, 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);
383 for_each_child_of_node(node, pp) {
384 enum of_gpio_flags flags;
386 if (!of_find_property(pp, "gpios", NULL)) {
388 dev_warn(dev, "Found button without gpios\n");
392 button = &pdata->buttons[i++];
394 button->gpio = of_get_gpio_flags(pp, 0, &flags);
395 if (button->gpio < 0) {
396 error = button->gpio;
397 if (error != -ENOENT) {
398 if (error != -EPROBE_DEFER)
400 "Failed to get gpio flags, error: %d\n",
402 return ERR_PTR(error);
405 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
408 if (of_property_read_u32(pp, "linux,code", &button->code)) {
409 dev_err(dev, "Button without keycode: 0x%x\n",
415 button->desc = of_get_property(pp, "label", NULL);
417 if (of_property_read_u32(pp, "linux,input-type", &button->type))
418 button->type = EV_KEY;
420 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
422 if (of_property_read_u32(pp, "debounce-interval",
423 &button->debounce_interval))
424 button->debounce_interval = 5;
427 if (pdata->nbuttons == 0) {
435 return ERR_PTR(error);
438 static struct of_device_id gpio_keys_of_match[] = {
439 { .compatible = "gpio-keys", },
442 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
444 static struct of_device_id gpio_keys_polled_of_match[] = {
445 { .compatible = "gpio-keys-polled", },
448 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
452 static inline struct gpio_keys_platform_data *
453 gpio_keys_get_devtree_pdata(struct device *dev)
459 static int gpio_keys_button_probe(struct platform_device *pdev,
460 struct gpio_keys_button_dev **_bdev, int polled)
462 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
463 struct device *dev = &pdev->dev;
464 struct gpio_keys_button_dev *bdev;
465 struct gpio_keys_button *buttons;
470 pdata = gpio_keys_get_devtree_pdata(dev);
472 return PTR_ERR(pdata);
474 dev_err(dev, "missing platform data\n");
479 if (polled && !pdata->poll_interval) {
480 dev_err(dev, "missing poll_interval value\n");
484 buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button),
487 dev_err(dev, "no memory for button data\n");
490 memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button));
492 bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) +
493 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
496 dev_err(dev, "no memory for private data\n");
500 bdev->polled = polled;
502 for (i = 0; i < pdata->nbuttons; i++) {
503 struct gpio_keys_button *button = &buttons[i];
504 struct gpio_keys_button_data *bdata = &bdev->data[i];
505 unsigned int gpio = button->gpio;
507 if (button->wakeup) {
508 dev_err(dev, DRV_NAME "does not support wakeup\n");
512 error = devm_gpio_request(dev, gpio,
513 button->desc ? button->desc : DRV_NAME);
515 dev_err(dev, "unable to claim gpio %u, err=%d\n",
520 error = gpio_direction_input(gpio);
523 "unable to set direction on gpio %u, err=%d\n",
528 bdata->can_sleep = gpio_cansleep(gpio);
529 bdata->last_state = -1;
532 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
533 pdata->poll_interval);
535 bdata->threshold = 1;
537 bdata->b = &pdata->buttons[i];
540 bdev->dev = &pdev->dev;
542 platform_set_drvdata(pdev, bdev);
549 static int gpio_keys_probe(struct platform_device *pdev)
551 struct gpio_keys_platform_data *pdata;
552 struct gpio_keys_button_dev *bdev;
556 ret = gpio_keys_button_probe(pdev, &bdev, 0);
562 for (i = 0; i < pdata->nbuttons; i++) {
563 struct gpio_keys_button *button = &pdata->buttons[i];
564 struct gpio_keys_button_data *bdata = &bdev->data[i];
567 button->irq = gpio_to_irq(button->gpio);
568 if (button->irq < 0) {
569 dev_err(&pdev->dev, "failed to get irq for gpio:%d\n", button->gpio);
573 ret = devm_request_threaded_irq(&pdev->dev, button->irq, NULL, button_handle_irq,
574 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
575 dev_name(&pdev->dev), bdata);
577 dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n", button->irq, button->gpio);
579 dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n", button->gpio, button->irq);
581 if (bdata->b->type == EV_SW)
582 button_hotplug_event(bdata, EV_SW, gpio_button_get_value(bdata));
588 static int gpio_keys_polled_probe(struct platform_device *pdev)
590 struct gpio_keys_platform_data *pdata;
591 struct gpio_keys_button_dev *bdev;
595 ret = gpio_keys_button_probe(pdev, &bdev, 1);
600 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
605 pdata->enable(bdev->dev);
607 for (i = 0; i < pdata->nbuttons; i++)
608 gpio_keys_polled_check_state(&bdev->data[i]);
610 gpio_keys_polled_queue_work(bdev);
615 static int gpio_keys_remove(struct platform_device *pdev)
617 struct gpio_keys_button_dev *bdev = platform_get_drvdata(pdev);
619 platform_set_drvdata(pdev, NULL);
622 gpio_keys_polled_close(bdev);
627 static struct platform_driver gpio_keys_driver = {
628 .probe = gpio_keys_probe,
629 .remove = gpio_keys_remove,
632 .owner = THIS_MODULE,
633 .of_match_table = of_match_ptr(gpio_keys_of_match),
637 static struct platform_driver gpio_keys_polled_driver = {
638 .probe = gpio_keys_polled_probe,
639 .remove = gpio_keys_remove,
641 .name = "gpio-keys-polled",
642 .owner = THIS_MODULE,
643 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
647 static int __init gpio_button_init(void)
651 ret = platform_driver_register(&gpio_keys_driver);
655 ret = platform_driver_register(&gpio_keys_polled_driver);
657 platform_driver_unregister(&gpio_keys_driver);
662 static void __exit gpio_button_exit(void)
664 platform_driver_unregister(&gpio_keys_driver);
665 platform_driver_unregister(&gpio_keys_polled_driver);
668 module_init(gpio_button_init);
669 module_exit(gpio_button_exit);
671 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
672 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
673 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
674 MODULE_LICENSE("GPL v2");
675 MODULE_ALIAS("platform:" DRV_NAME);