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/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_POWER, "power"),
96 BH_MAP(KEY_RESTART, "reset"),
97 BH_MAP(KEY_RFKILL, "rfkill"),
98 BH_MAP(KEY_WPS_BUTTON, "wps"),
99 BH_MAP(KEY_WIMAX, "wwan"),
102 /* -------------------------------------------------------------------------*/
104 static int bh_event_add_var(struct bh_event *event, int argv,
105 const char *format, ...)
107 static char buf[128];
115 va_start(args, format);
116 len = vsnprintf(buf, sizeof(buf), format, args);
119 if (len >= sizeof(buf)) {
120 BH_ERR("buffer size too small\n");
125 s = skb_put(event->skb, len + 1);
128 BH_DBG("added variable '%s'\n", s);
133 static int button_hotplug_fill_event(struct bh_event *event)
137 ret = bh_event_add_var(event, 0, "HOME=%s", "/");
141 ret = bh_event_add_var(event, 0, "PATH=%s",
142 "/sbin:/bin:/usr/sbin:/usr/bin");
146 ret = bh_event_add_var(event, 0, "SUBSYSTEM=%s", "button");
150 ret = bh_event_add_var(event, 0, "ACTION=%s", event->action);
154 ret = bh_event_add_var(event, 0, "BUTTON=%s", event->name);
158 if (event->type == EV_SW) {
159 ret = bh_event_add_var(event, 0, "TYPE=%s", "switch");
164 ret = bh_event_add_var(event, 0, "SEEN=%ld", event->seen);
168 ret = bh_event_add_var(event, 0, "SEQNUM=%llu", uevent_next_seqnum());
173 static void button_hotplug_work(struct work_struct *work)
175 struct bh_event *event = container_of(work, struct bh_event, work);
178 event->skb = alloc_skb(BH_SKB_SIZE, GFP_KERNEL);
182 ret = bh_event_add_var(event, 0, "%s@", event->action);
186 ret = button_hotplug_fill_event(event);
190 NETLINK_CB(event->skb).dst_group = 1;
191 broadcast_uevent(event->skb, 0, 1, GFP_KERNEL);
195 BH_ERR("work error %d\n", ret);
196 kfree_skb(event->skb);
202 static int button_hotplug_create_event(const char *name, unsigned int type,
203 unsigned long seen, int pressed)
205 struct bh_event *event;
207 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
208 name, seen, pressed);
210 event = kzalloc(sizeof(*event), GFP_KERNEL);
217 event->action = pressed ? "pressed" : "released";
219 INIT_WORK(&event->work, (void *)(void *)button_hotplug_work);
220 schedule_work(&event->work);
225 /* -------------------------------------------------------------------------*/
227 #ifdef CONFIG_HOTPLUG
228 static int button_get_index(unsigned int code)
232 for (i = 0; i < ARRAY_SIZE(button_map); i++)
233 if (button_map[i].code == code)
239 static void button_hotplug_event(struct gpio_keys_button_data *data,
240 unsigned int type, int value)
242 struct bh_priv *priv = &data->bh;
243 unsigned long seen = jiffies;
246 BH_DBG("event type=%u, code=%u, value=%d\n", type, data->b->code, value);
248 if ((type != EV_KEY) && (type != EV_SW))
251 btn = button_get_index(data->b->code);
255 button_hotplug_create_event(button_map[btn].name, type,
256 (seen - priv->seen) / HZ, value);
260 static void button_hotplug_event(struct gpio_keys_button_data *data,
261 unsigned int type, int value)
264 #endif /* CONFIG_HOTPLUG */
266 struct gpio_keys_button_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_data *bdata)
279 if (bdata->can_sleep)
280 val = !!gpio_get_value_cansleep(bdata->b->gpio);
282 val = !!gpio_get_value(bdata->b->gpio);
284 return val ^ bdata->b->active_low;
287 static void gpio_keys_polled_check_state(struct gpio_keys_button_data *bdata)
289 int state = gpio_button_get_value(bdata);
291 if (state != bdata->last_state) {
292 unsigned int type = bdata->b->type ?: EV_KEY;
294 if (bdata->count < bdata->threshold) {
299 if ((bdata->last_state != -1) || (type == EV_SW))
300 button_hotplug_event(bdata, type, state);
302 bdata->last_state = state;
308 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
310 struct gpio_keys_platform_data *pdata = bdev->pdata;
311 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
314 delay = round_jiffies_relative(delay);
315 schedule_delayed_work(&bdev->work, delay);
318 static void gpio_keys_polled_poll(struct work_struct *work)
320 struct gpio_keys_button_dev *bdev =
321 container_of(work, struct gpio_keys_button_dev, work.work);
324 for (i = 0; i < bdev->pdata->nbuttons; i++) {
325 struct gpio_keys_button_data *bdata = &bdev->data[i];
326 gpio_keys_polled_check_state(bdata);
328 gpio_keys_polled_queue_work(bdev);
331 static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev)
333 struct gpio_keys_platform_data *pdata = bdev->pdata;
335 cancel_delayed_work_sync(&bdev->work);
338 pdata->disable(bdev->dev);
341 static irqreturn_t button_handle_irq(int irq, void *_bdata)
343 struct gpio_keys_button_data *bdata = (struct gpio_keys_button_data *) _bdata;
345 button_hotplug_event(bdata, bdata->b->type ?: EV_KEY, gpio_button_get_value(bdata));
351 static struct gpio_keys_platform_data *
352 gpio_keys_get_devtree_pdata(struct device *dev)
354 struct device_node *node, *pp;
355 struct gpio_keys_platform_data *pdata;
356 struct gpio_keys_button *button;
365 nbuttons = of_get_child_count(node);
369 pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * (sizeof *button),
376 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
377 pdata->nbuttons = nbuttons;
379 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
380 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) {
423 return ERR_PTR(error);
426 static struct of_device_id gpio_keys_of_match[] = {
427 { .compatible = "gpio-keys", },
430 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
432 static struct of_device_id gpio_keys_polled_of_match[] = {
433 { .compatible = "gpio-keys-polled", },
436 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
440 static inline struct gpio_keys_platform_data *
441 gpio_keys_get_devtree_pdata(struct device *dev)
447 static int gpio_keys_button_probe(struct platform_device *pdev,
448 struct gpio_keys_button_dev **_bdev, int polled)
450 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
451 struct device *dev = &pdev->dev;
452 struct gpio_keys_button_dev *bdev;
453 struct gpio_keys_button *buttons;
458 pdata = gpio_keys_get_devtree_pdata(dev);
460 return PTR_ERR(pdata);
462 dev_err(dev, "missing platform data\n");
465 pdev->dev.platform_data = pdata;
468 if (polled && !pdata->poll_interval) {
469 dev_err(dev, "missing poll_interval value\n");
473 buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button),
476 dev_err(dev, "no memory for button data\n");
479 memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button));
481 bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) +
482 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
485 dev_err(dev, "no memory for private data\n");
489 bdev->polled = polled;
491 for (i = 0; i < pdata->nbuttons; i++) {
492 struct gpio_keys_button *button = &buttons[i];
493 struct gpio_keys_button_data *bdata = &bdev->data[i];
494 unsigned int gpio = button->gpio;
496 if (button->wakeup) {
497 dev_err(dev, DRV_NAME "does not support wakeup\n");
501 error = devm_gpio_request(dev, gpio,
502 button->desc ? button->desc : DRV_NAME);
504 dev_err(dev, "unable to claim gpio %u, err=%d\n",
509 error = gpio_direction_input(gpio);
512 "unable to set direction on gpio %u, err=%d\n",
517 bdata->can_sleep = gpio_cansleep(gpio);
518 bdata->last_state = -1;
521 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
522 pdata->poll_interval);
524 bdata->threshold = 1;
526 bdata->b = &pdata->buttons[i];
529 bdev->dev = &pdev->dev;
531 platform_set_drvdata(pdev, bdev);
538 static int gpio_keys_probe(struct platform_device *pdev)
540 struct gpio_keys_platform_data *pdata;
541 struct gpio_keys_button_dev *bdev;
545 ret = gpio_keys_button_probe(pdev, &bdev, 0);
550 pdata = pdev->dev.platform_data;
551 for (i = 0; i < pdata->nbuttons; i++) {
552 struct gpio_keys_button *button = &pdata->buttons[i];
553 struct gpio_keys_button_data *bdata = &bdev->data[i];
555 if (bdata->can_sleep) {
556 dev_err(&pdev->dev, "skipping gpio:%d, it can sleep\n", button->gpio);
560 button->irq = gpio_to_irq(button->gpio);
561 if (button->irq < 0) {
562 dev_err(&pdev->dev, "failed to get irq for gpio:%d\n", button->gpio);
565 ret = devm_request_irq(&pdev->dev, button->irq, button_handle_irq,
566 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
567 dev_name(&pdev->dev), bdata);
569 dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n", button->irq, button->gpio);
571 dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n", button->gpio, button->irq);
573 if (bdata->b->type == EV_SW)
574 button_hotplug_event(bdata, EV_SW, gpio_button_get_value(bdata));
580 static int gpio_keys_polled_probe(struct platform_device *pdev)
582 struct gpio_keys_platform_data *pdata;
583 struct gpio_keys_button_dev *bdev;
587 ret = gpio_keys_button_probe(pdev, &bdev, 1);
592 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
597 pdata->enable(bdev->dev);
599 for (i = 0; i < pdata->nbuttons; i++)
600 gpio_keys_polled_check_state(&bdev->data[i]);
602 gpio_keys_polled_queue_work(bdev);
607 static int gpio_keys_remove(struct platform_device *pdev)
609 struct gpio_keys_button_dev *bdev = platform_get_drvdata(pdev);
611 platform_set_drvdata(pdev, NULL);
614 gpio_keys_polled_close(bdev);
619 static struct platform_driver gpio_keys_driver = {
620 .probe = gpio_keys_probe,
621 .remove = gpio_keys_remove,
624 .owner = THIS_MODULE,
625 .of_match_table = of_match_ptr(gpio_keys_of_match),
629 static struct platform_driver gpio_keys_polled_driver = {
630 .probe = gpio_keys_polled_probe,
631 .remove = gpio_keys_remove,
633 .name = "gpio-keys-polled",
634 .owner = THIS_MODULE,
635 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
639 static int __init gpio_button_init(void)
643 ret = platform_driver_register(&gpio_keys_driver);
647 ret = platform_driver_register(&gpio_keys_polled_driver);
649 platform_driver_unregister(&gpio_keys_driver);
654 static void __exit gpio_button_exit(void)
656 platform_driver_unregister(&gpio_keys_driver);
657 platform_driver_unregister(&gpio_keys_polled_driver);
660 module_init(gpio_button_init);
661 module_exit(gpio_button_exit);
663 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
664 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
665 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
666 MODULE_LICENSE("GPL v2");
667 MODULE_ALIAS("platform:" DRV_NAME);