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 static int button_get_index(unsigned int code)
231 for (i = 0; i < ARRAY_SIZE(button_map); i++)
232 if (button_map[i].code == code)
238 static void button_hotplug_event(struct gpio_keys_button_data *data,
239 unsigned int type, int value)
241 struct bh_priv *priv = &data->bh;
242 unsigned long seen = jiffies;
245 BH_DBG("event type=%u, code=%u, value=%d\n", type, data->b->code, value);
247 if ((type != EV_KEY) && (type != EV_SW))
250 btn = button_get_index(data->b->code);
254 button_hotplug_create_event(button_map[btn].name, type,
255 (seen - priv->seen) / HZ, value);
259 struct gpio_keys_button_dev {
261 struct delayed_work work;
264 struct gpio_keys_platform_data *pdata;
265 struct gpio_keys_button_data data[0];
268 static int gpio_button_get_value(struct gpio_keys_button_data *bdata)
272 if (bdata->can_sleep)
273 val = !!gpio_get_value_cansleep(bdata->b->gpio);
275 val = !!gpio_get_value(bdata->b->gpio);
277 return val ^ bdata->b->active_low;
280 static void gpio_keys_polled_check_state(struct gpio_keys_button_data *bdata)
282 int state = gpio_button_get_value(bdata);
284 if (state != bdata->last_state) {
285 unsigned int type = bdata->b->type ?: EV_KEY;
287 if (bdata->count < bdata->threshold) {
292 if ((bdata->last_state != -1) || (type == EV_SW))
293 button_hotplug_event(bdata, type, state);
295 bdata->last_state = state;
301 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev *bdev)
303 struct gpio_keys_platform_data *pdata = bdev->pdata;
304 unsigned long delay = msecs_to_jiffies(pdata->poll_interval);
307 delay = round_jiffies_relative(delay);
308 schedule_delayed_work(&bdev->work, delay);
311 static void gpio_keys_polled_poll(struct work_struct *work)
313 struct gpio_keys_button_dev *bdev =
314 container_of(work, struct gpio_keys_button_dev, work.work);
317 for (i = 0; i < bdev->pdata->nbuttons; i++) {
318 struct gpio_keys_button_data *bdata = &bdev->data[i];
319 gpio_keys_polled_check_state(bdata);
321 gpio_keys_polled_queue_work(bdev);
324 static void gpio_keys_polled_close(struct gpio_keys_button_dev *bdev)
326 struct gpio_keys_platform_data *pdata = bdev->pdata;
328 cancel_delayed_work_sync(&bdev->work);
331 pdata->disable(bdev->dev);
334 static irqreturn_t button_handle_irq(int irq, void *_bdata)
336 struct gpio_keys_button_data *bdata = (struct gpio_keys_button_data *) _bdata;
338 button_hotplug_event(bdata, bdata->b->type ?: EV_KEY, gpio_button_get_value(bdata));
344 static struct gpio_keys_platform_data *
345 gpio_keys_get_devtree_pdata(struct device *dev)
347 struct device_node *node, *pp;
348 struct gpio_keys_platform_data *pdata;
349 struct gpio_keys_button *button;
358 nbuttons = of_get_child_count(node);
362 pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * (sizeof *button),
369 pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
370 pdata->nbuttons = nbuttons;
372 pdata->rep = !!of_get_property(node, "autorepeat", NULL);
373 of_property_read_u32(node, "poll-interval", &pdata->poll_interval);
375 for_each_child_of_node(node, pp) {
376 enum of_gpio_flags flags;
378 if (!of_find_property(pp, "gpios", NULL)) {
380 dev_warn(dev, "Found button without gpios\n");
384 button = &pdata->buttons[i++];
386 button->gpio = of_get_gpio_flags(pp, 0, &flags);
387 button->active_low = flags & OF_GPIO_ACTIVE_LOW;
389 if (of_property_read_u32(pp, "linux,code", &button->code)) {
390 dev_err(dev, "Button without keycode: 0x%x\n",
396 button->desc = of_get_property(pp, "label", NULL);
398 if (of_property_read_u32(pp, "linux,input-type", &button->type))
399 button->type = EV_KEY;
401 button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
403 if (of_property_read_u32(pp, "debounce-interval",
404 &button->debounce_interval))
405 button->debounce_interval = 5;
408 if (pdata->nbuttons == 0) {
416 return ERR_PTR(error);
419 static struct of_device_id gpio_keys_of_match[] = {
420 { .compatible = "gpio-keys", },
423 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
425 static struct of_device_id gpio_keys_polled_of_match[] = {
426 { .compatible = "gpio-keys-polled", },
429 MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match);
433 static inline struct gpio_keys_platform_data *
434 gpio_keys_get_devtree_pdata(struct device *dev)
440 static int gpio_keys_button_probe(struct platform_device *pdev,
441 struct gpio_keys_button_dev **_bdev, int polled)
443 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
444 struct device *dev = &pdev->dev;
445 struct gpio_keys_button_dev *bdev;
446 struct gpio_keys_button *buttons;
451 pdata = gpio_keys_get_devtree_pdata(dev);
453 return PTR_ERR(pdata);
455 dev_err(dev, "missing platform data\n");
458 pdev->dev.platform_data = pdata;
461 if (polled && !pdata->poll_interval) {
462 dev_err(dev, "missing poll_interval value\n");
466 buttons = devm_kzalloc(dev, pdata->nbuttons * sizeof(struct gpio_keys_button),
469 dev_err(dev, "no memory for button data\n");
472 memcpy(buttons, pdata->buttons, pdata->nbuttons * sizeof(struct gpio_keys_button));
474 bdev = devm_kzalloc(dev, sizeof(struct gpio_keys_button_dev) +
475 pdata->nbuttons * sizeof(struct gpio_keys_button_data),
478 dev_err(dev, "no memory for private data\n");
482 bdev->polled = polled;
484 for (i = 0; i < pdata->nbuttons; i++) {
485 struct gpio_keys_button *button = &buttons[i];
486 struct gpio_keys_button_data *bdata = &bdev->data[i];
487 unsigned int gpio = button->gpio;
489 if (button->wakeup) {
490 dev_err(dev, DRV_NAME "does not support wakeup\n");
494 error = devm_gpio_request(dev, gpio,
495 button->desc ? button->desc : DRV_NAME);
497 dev_err(dev, "unable to claim gpio %u, err=%d\n",
502 error = gpio_direction_input(gpio);
505 "unable to set direction on gpio %u, err=%d\n",
510 bdata->can_sleep = gpio_cansleep(gpio);
511 bdata->last_state = -1;
514 bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
515 pdata->poll_interval);
517 bdata->threshold = 1;
519 bdata->b = &pdata->buttons[i];
522 bdev->dev = &pdev->dev;
524 platform_set_drvdata(pdev, bdev);
531 static int gpio_keys_probe(struct platform_device *pdev)
533 struct gpio_keys_platform_data *pdata;
534 struct gpio_keys_button_dev *bdev;
538 ret = gpio_keys_button_probe(pdev, &bdev, 0);
543 pdata = pdev->dev.platform_data;
544 for (i = 0; i < pdata->nbuttons; i++) {
545 struct gpio_keys_button *button = &pdata->buttons[i];
546 struct gpio_keys_button_data *bdata = &bdev->data[i];
548 if (bdata->can_sleep) {
549 dev_err(&pdev->dev, "skipping gpio:%d, it can sleep\n", button->gpio);
553 button->irq = gpio_to_irq(button->gpio);
554 if (button->irq < 0) {
555 dev_err(&pdev->dev, "failed to get irq for gpio:%d\n", button->gpio);
558 ret = devm_request_irq(&pdev->dev, button->irq, button_handle_irq,
559 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
560 dev_name(&pdev->dev), bdata);
562 dev_err(&pdev->dev, "failed to request irq:%d for gpio:%d\n", button->irq, button->gpio);
564 dev_dbg(&pdev->dev, "gpio:%d has irq:%d\n", button->gpio, button->irq);
566 if (bdata->b->type == EV_SW)
567 button_hotplug_event(bdata, EV_SW, gpio_button_get_value(bdata));
573 static int gpio_keys_polled_probe(struct platform_device *pdev)
575 struct gpio_keys_platform_data *pdata;
576 struct gpio_keys_button_dev *bdev;
580 ret = gpio_keys_button_probe(pdev, &bdev, 1);
585 INIT_DELAYED_WORK(&bdev->work, gpio_keys_polled_poll);
590 pdata->enable(bdev->dev);
592 for (i = 0; i < pdata->nbuttons; i++)
593 gpio_keys_polled_check_state(&bdev->data[i]);
595 gpio_keys_polled_queue_work(bdev);
600 static int gpio_keys_remove(struct platform_device *pdev)
602 struct gpio_keys_button_dev *bdev = platform_get_drvdata(pdev);
604 platform_set_drvdata(pdev, NULL);
607 gpio_keys_polled_close(bdev);
612 static struct platform_driver gpio_keys_driver = {
613 .probe = gpio_keys_probe,
614 .remove = gpio_keys_remove,
617 .owner = THIS_MODULE,
618 .of_match_table = of_match_ptr(gpio_keys_of_match),
622 static struct platform_driver gpio_keys_polled_driver = {
623 .probe = gpio_keys_polled_probe,
624 .remove = gpio_keys_remove,
626 .name = "gpio-keys-polled",
627 .owner = THIS_MODULE,
628 .of_match_table = of_match_ptr(gpio_keys_polled_of_match),
632 static int __init gpio_button_init(void)
636 ret = platform_driver_register(&gpio_keys_driver);
640 ret = platform_driver_register(&gpio_keys_polled_driver);
642 platform_driver_unregister(&gpio_keys_driver);
647 static void __exit gpio_button_exit(void)
649 platform_driver_unregister(&gpio_keys_driver);
650 platform_driver_unregister(&gpio_keys_polled_driver);
653 module_init(gpio_button_init);
654 module_exit(gpio_button_exit);
656 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
657 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
658 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
659 MODULE_LICENSE("GPL v2");
660 MODULE_ALIAS("platform:" DRV_NAME);