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
);