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/of_irq.h>
30 #include <linux/gpio_keys.h>
32 #define DRV_NAME "gpio-keys"
34 #define BH_SKB_SIZE 2048
36 #define PFX DRV_NAME ": "
41 #define BH_DBG(fmt, args...) printk(KERN_DEBUG "%s: " fmt, DRV_NAME, ##args )
43 #define BH_DBG(fmt, args...) do {} while (0)
46 #define BH_ERR(fmt, args...) printk(KERN_ERR "%s: " fmt, DRV_NAME, ##args )
59 struct work_struct work
;
67 struct gpio_keys_button_data
{
68 struct delayed_work work
;
75 unsigned int software_debounce
;
76 struct gpio_desc
*gpiod
;
77 const struct gpio_keys_button
*b
;
80 extern u64
uevent_next_seqnum(void);
82 #define BH_MAP(_code, _name) \
88 static struct bh_map button_map
[] = {
89 BH_MAP(BTN_0
, "BTN_0"),
90 BH_MAP(BTN_1
, "BTN_1"),
91 BH_MAP(BTN_2
, "BTN_2"),
92 BH_MAP(BTN_3
, "BTN_3"),
93 BH_MAP(BTN_4
, "BTN_4"),
94 BH_MAP(BTN_5
, "BTN_5"),
95 BH_MAP(BTN_6
, "BTN_6"),
96 BH_MAP(BTN_7
, "BTN_7"),
97 BH_MAP(BTN_8
, "BTN_8"),
98 BH_MAP(BTN_9
, "BTN_9"),
99 BH_MAP(KEY_BRIGHTNESS_ZERO
, "brightness_zero"),
100 BH_MAP(KEY_CONFIG
, "config"),
101 BH_MAP(KEY_COPY
, "copy"),
102 BH_MAP(KEY_EJECTCD
, "eject"),
103 BH_MAP(KEY_HELP
, "help"),
104 BH_MAP(KEY_LIGHTS_TOGGLE
, "lights_toggle"),
105 BH_MAP(KEY_PHONE
, "phone"),
106 BH_MAP(KEY_POWER
, "power"),
107 BH_MAP(KEY_POWER2
, "reboot"),
108 BH_MAP(KEY_RESTART
, "reset"),
109 BH_MAP(KEY_RFKILL
, "rfkill"),
110 BH_MAP(KEY_VIDEO
, "video"),
111 BH_MAP(KEY_WIMAX
, "wwan"),
112 BH_MAP(KEY_WLAN
, "wlan"),
113 BH_MAP(KEY_WPS_BUTTON
, "wps"),
116 /* -------------------------------------------------------------------------*/
118 static __printf(3, 4)
119 int bh_event_add_var(struct bh_event
*event
, int argv
, const char *format
, ...)
121 static char buf
[128];
129 va_start(args
, format
);
130 len
= vsnprintf(buf
, sizeof(buf
), format
, args
);
133 if (len
>= sizeof(buf
)) {
134 WARN(1, "buffer size too small");
138 s
= skb_put(event
->skb
, len
+ 1);
141 BH_DBG("added variable '%s'\n", s
);
146 static int button_hotplug_fill_event(struct bh_event
*event
)
150 ret
= bh_event_add_var(event
, 0, "HOME=%s", "/");
154 ret
= bh_event_add_var(event
, 0, "PATH=%s",
155 "/sbin:/bin:/usr/sbin:/usr/bin");
159 ret
= bh_event_add_var(event
, 0, "SUBSYSTEM=%s", "button");
163 ret
= bh_event_add_var(event
, 0, "ACTION=%s", event
->action
);
167 ret
= bh_event_add_var(event
, 0, "BUTTON=%s", event
->name
);
171 if (event
->type
== EV_SW
) {
172 ret
= bh_event_add_var(event
, 0, "TYPE=%s", "switch");
177 ret
= bh_event_add_var(event
, 0, "SEEN=%ld", event
->seen
);
181 ret
= bh_event_add_var(event
, 0, "SEQNUM=%llu", uevent_next_seqnum());
186 static void button_hotplug_work(struct work_struct
*work
)
188 struct bh_event
*event
= container_of(work
, struct bh_event
, work
);
191 event
->skb
= alloc_skb(BH_SKB_SIZE
, GFP_KERNEL
);
195 ret
= bh_event_add_var(event
, 0, "%s@", event
->action
);
199 ret
= button_hotplug_fill_event(event
);
203 NETLINK_CB(event
->skb
).dst_group
= 1;
204 broadcast_uevent(event
->skb
, 0, 1, GFP_KERNEL
);
208 BH_ERR("work error %d\n", ret
);
209 kfree_skb(event
->skb
);
215 static int button_hotplug_create_event(const char *name
, unsigned int type
,
216 unsigned long seen
, int pressed
)
218 struct bh_event
*event
;
220 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
221 name
, seen
, pressed
);
223 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
230 event
->action
= pressed
? "pressed" : "released";
232 INIT_WORK(&event
->work
, (void *)(void *)button_hotplug_work
);
233 schedule_work(&event
->work
);
238 /* -------------------------------------------------------------------------*/
240 static int button_get_index(unsigned int code
)
244 for (i
= 0; i
< ARRAY_SIZE(button_map
); i
++)
245 if (button_map
[i
].code
== code
)
251 static void button_hotplug_event(struct gpio_keys_button_data
*data
,
252 unsigned int type
, int value
)
254 struct bh_priv
*priv
= &data
->bh
;
255 unsigned long seen
= jiffies
;
258 BH_DBG("event type=%u, code=%u, value=%d\n", type
, data
->b
->code
, value
);
260 if ((type
!= EV_KEY
) && (type
!= EV_SW
))
263 btn
= button_get_index(data
->b
->code
);
267 button_hotplug_create_event(button_map
[btn
].name
, type
,
268 (seen
- priv
->seen
) / HZ
, value
);
272 struct gpio_keys_button_dev
{
274 struct delayed_work work
;
277 struct gpio_keys_platform_data
*pdata
;
278 struct gpio_keys_button_data data
[0];
281 static int gpio_button_get_value(struct gpio_keys_button_data
*bdata
)
285 if (bdata
->can_sleep
)
286 val
= !!gpio_get_value_cansleep(bdata
->b
->gpio
);
288 val
= !!gpio_get_value(bdata
->b
->gpio
);
290 return val
^ bdata
->b
->active_low
;
293 static void gpio_keys_polled_check_state(struct gpio_keys_button_data
*bdata
)
295 int state
= gpio_button_get_value(bdata
);
297 if (state
!= bdata
->last_state
) {
298 unsigned int type
= bdata
->b
->type
?: EV_KEY
;
300 if (bdata
->count
< bdata
->threshold
) {
305 if (bdata
->last_state
!= -1 || type
== EV_SW
)
306 button_hotplug_event(bdata
, type
, state
);
308 bdata
->last_state
= state
;
314 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev
*bdev
)
316 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
317 unsigned long delay
= msecs_to_jiffies(pdata
->poll_interval
);
320 delay
= round_jiffies_relative(delay
);
321 schedule_delayed_work(&bdev
->work
, delay
);
324 static void gpio_keys_polled_poll(struct work_struct
*work
)
326 struct gpio_keys_button_dev
*bdev
=
327 container_of(work
, struct gpio_keys_button_dev
, work
.work
);
330 for (i
= 0; i
< bdev
->pdata
->nbuttons
; i
++) {
331 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
332 gpio_keys_polled_check_state(bdata
);
334 gpio_keys_polled_queue_work(bdev
);
337 static void gpio_keys_polled_close(struct gpio_keys_button_dev
*bdev
)
339 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
341 cancel_delayed_work_sync(&bdev
->work
);
344 pdata
->disable(bdev
->dev
);
347 static void gpio_keys_irq_work_func(struct work_struct
*work
)
349 struct gpio_keys_button_data
*bdata
= container_of(work
,
350 struct gpio_keys_button_data
, work
.work
);
351 int state
= gpio_button_get_value(bdata
);
353 if (state
!= bdata
->last_state
) {
354 unsigned int type
= bdata
->b
->type
?: EV_KEY
;
356 if (bdata
->last_state
!= -1 || type
== EV_SW
)
357 button_hotplug_event(bdata
, type
, state
);
359 bdata
->last_state
= state
;
363 static irqreturn_t
button_handle_irq(int irq
, void *_bdata
)
365 struct gpio_keys_button_data
*bdata
=
366 (struct gpio_keys_button_data
*) _bdata
;
368 schedule_delayed_work(&bdata
->work
,
369 msecs_to_jiffies(bdata
->software_debounce
));
375 static struct gpio_keys_platform_data
*
376 gpio_keys_get_devtree_pdata(struct device
*dev
)
378 struct device_node
*node
, *pp
;
379 struct gpio_keys_platform_data
*pdata
;
380 struct gpio_keys_button
*button
;
389 nbuttons
= of_get_child_count(node
);
393 pdata
= devm_kzalloc(dev
, sizeof(*pdata
) + nbuttons
* (sizeof *button
),
400 pdata
->buttons
= (struct gpio_keys_button
*)(pdata
+ 1);
401 pdata
->nbuttons
= nbuttons
;
403 pdata
->rep
= !!of_get_property(node
, "autorepeat", NULL
);
404 of_property_read_u32(node
, "poll-interval", &pdata
->poll_interval
);
406 for_each_child_of_node(node
, pp
) {
407 enum of_gpio_flags flags
;
409 if (!of_find_property(pp
, "gpios", NULL
)) {
411 dev_warn(dev
, "Found button without gpios\n");
415 button
= (struct gpio_keys_button
*)(&pdata
->buttons
[i
++]);
417 button
->irq
= irq_of_parse_and_map(pp
, 0);
419 button
->gpio
= of_get_gpio_flags(pp
, 0, &flags
);
420 if (button
->gpio
< 0) {
421 error
= button
->gpio
;
422 if (error
!= -ENOENT
) {
423 if (error
!= -EPROBE_DEFER
)
425 "Failed to get gpio flags, error: %d\n",
427 return ERR_PTR(error
);
430 button
->active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
433 if (of_property_read_u32(pp
, "linux,code", &button
->code
)) {
434 dev_err(dev
, "Button without keycode: 0x%x\n",
440 button
->desc
= of_get_property(pp
, "label", NULL
);
442 if (of_property_read_u32(pp
, "linux,input-type", &button
->type
))
443 button
->type
= EV_KEY
;
445 button
->wakeup
= !!of_get_property(pp
, "gpio-key,wakeup", NULL
);
447 if (of_property_read_u32(pp
, "debounce-interval",
448 &button
->debounce_interval
))
449 button
->debounce_interval
= 5;
452 if (pdata
->nbuttons
== 0) {
460 return ERR_PTR(error
);
463 static struct of_device_id gpio_keys_of_match
[] = {
464 { .compatible
= "gpio-keys", },
467 MODULE_DEVICE_TABLE(of
, gpio_keys_of_match
);
469 static struct of_device_id gpio_keys_polled_of_match
[] = {
470 { .compatible
= "gpio-keys-polled", },
473 MODULE_DEVICE_TABLE(of
, gpio_keys_polled_of_match
);
477 static inline struct gpio_keys_platform_data
*
478 gpio_keys_get_devtree_pdata(struct device
*dev
)
484 static int gpio_keys_button_probe(struct platform_device
*pdev
,
485 struct gpio_keys_button_dev
**_bdev
, int polled
)
487 struct gpio_keys_platform_data
*pdata
= pdev
->dev
.platform_data
;
488 struct device
*dev
= &pdev
->dev
;
489 struct gpio_keys_button_dev
*bdev
;
490 struct gpio_keys_button
*buttons
;
495 pdata
= gpio_keys_get_devtree_pdata(dev
);
497 return PTR_ERR(pdata
);
499 dev_err(dev
, "missing platform data\n");
504 if (polled
&& !pdata
->poll_interval
) {
505 dev_err(dev
, "missing poll_interval value\n");
509 buttons
= devm_kzalloc(dev
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
),
512 dev_err(dev
, "no memory for button data\n");
515 memcpy(buttons
, pdata
->buttons
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
));
517 bdev
= devm_kzalloc(dev
, sizeof(struct gpio_keys_button_dev
) +
518 pdata
->nbuttons
* sizeof(struct gpio_keys_button_data
),
521 dev_err(dev
, "no memory for private data\n");
525 bdev
->polled
= polled
;
527 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
528 struct gpio_keys_button
*button
= &buttons
[i
];
529 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
530 unsigned int gpio
= button
->gpio
;
532 if (button
->wakeup
) {
533 dev_err(dev
, DRV_NAME
"does not support wakeup\n");
537 error
= devm_gpio_request(dev
, gpio
,
538 button
->desc
? button
->desc
: DRV_NAME
);
540 dev_err(dev
, "unable to claim gpio %u, err=%d\n",
544 bdata
->gpiod
= gpio_to_desc(gpio
);
548 error
= gpio_direction_input(gpio
);
551 "unable to set direction on gpio %u, err=%d\n",
556 bdata
->can_sleep
= gpio_cansleep(gpio
);
557 bdata
->last_state
= -1;
560 bdata
->threshold
= DIV_ROUND_UP(button
->debounce_interval
,
561 pdata
->poll_interval
);
563 bdata
->threshold
= 1;
565 if (button
->debounce_interval
) {
566 error
= gpiod_set_debounce(bdata
->gpiod
,
567 button
->debounce_interval
* 1000);
569 * use timer if gpiolib doesn't provide
573 bdata
->software_debounce
=
574 button
->debounce_interval
;
579 bdata
->b
= &pdata
->buttons
[i
];
582 bdev
->dev
= &pdev
->dev
;
584 platform_set_drvdata(pdev
, bdev
);
591 static int gpio_keys_probe(struct platform_device
*pdev
)
593 struct gpio_keys_platform_data
*pdata
;
594 struct gpio_keys_button_dev
*bdev
;
598 ret
= gpio_keys_button_probe(pdev
, &bdev
, 0);
604 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
605 const struct gpio_keys_button
*button
= &pdata
->buttons
[i
];
606 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
607 unsigned long irqflags
= IRQF_ONESHOT
;
610 bdata
->irq
= gpio_to_irq(button
->gpio
);
612 if (bdata
->irq
< 0) {
613 dev_err(&pdev
->dev
, "failed to get irq for gpio:%d\n",
618 irqflags
|= IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING
;
620 bdata
->irq
= button
->irq
;
623 INIT_DELAYED_WORK(&bdata
->work
, gpio_keys_irq_work_func
);
625 ret
= devm_request_threaded_irq(&pdev
->dev
,
626 bdata
->irq
, NULL
, button_handle_irq
,
627 irqflags
, dev_name(&pdev
->dev
), bdata
);
631 dev_err(&pdev
->dev
, "failed to request irq:%d for gpio:%d\n",
632 bdata
->irq
, button
->gpio
);
635 dev_dbg(&pdev
->dev
, "gpio:%d has irq:%d\n",
636 button
->gpio
, bdata
->irq
);
639 if (bdata
->b
->type
== EV_SW
)
640 button_hotplug_event(bdata
, EV_SW
, gpio_button_get_value(bdata
));
646 static int gpio_keys_polled_probe(struct platform_device
*pdev
)
648 struct gpio_keys_platform_data
*pdata
;
649 struct gpio_keys_button_dev
*bdev
;
653 ret
= gpio_keys_button_probe(pdev
, &bdev
, 1);
658 INIT_DELAYED_WORK(&bdev
->work
, gpio_keys_polled_poll
);
663 pdata
->enable(bdev
->dev
);
665 for (i
= 0; i
< pdata
->nbuttons
; i
++)
666 gpio_keys_polled_check_state(&bdev
->data
[i
]);
668 gpio_keys_polled_queue_work(bdev
);
673 static void gpio_keys_irq_close(struct gpio_keys_button_dev
*bdev
)
675 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
678 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
679 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
681 disable_irq(bdata
->irq
);
682 cancel_delayed_work_sync(&bdata
->work
);
686 static int gpio_keys_remove(struct platform_device
*pdev
)
688 struct gpio_keys_button_dev
*bdev
= platform_get_drvdata(pdev
);
690 platform_set_drvdata(pdev
, NULL
);
693 gpio_keys_polled_close(bdev
);
695 gpio_keys_irq_close(bdev
);
700 static struct platform_driver gpio_keys_driver
= {
701 .probe
= gpio_keys_probe
,
702 .remove
= gpio_keys_remove
,
705 .owner
= THIS_MODULE
,
706 .of_match_table
= of_match_ptr(gpio_keys_of_match
),
710 static struct platform_driver gpio_keys_polled_driver
= {
711 .probe
= gpio_keys_polled_probe
,
712 .remove
= gpio_keys_remove
,
714 .name
= "gpio-keys-polled",
715 .owner
= THIS_MODULE
,
716 .of_match_table
= of_match_ptr(gpio_keys_polled_of_match
),
720 static int __init
gpio_button_init(void)
724 ret
= platform_driver_register(&gpio_keys_driver
);
728 ret
= platform_driver_register(&gpio_keys_polled_driver
);
730 platform_driver_unregister(&gpio_keys_driver
);
735 static void __exit
gpio_button_exit(void)
737 platform_driver_unregister(&gpio_keys_driver
);
738 platform_driver_unregister(&gpio_keys_polled_driver
);
741 module_init(gpio_button_init
);
742 module_exit(gpio_button_exit
);
744 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
745 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
746 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
747 MODULE_LICENSE("GPL v2");
748 MODULE_ALIAS("platform:" DRV_NAME
);