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 BH_SKB_SIZE 2048
34 #define DRV_NAME "gpio-keys"
35 #define PFX DRV_NAME ": "
48 struct work_struct work
;
56 struct gpio_keys_button_data
{
57 struct delayed_work work
;
64 unsigned int software_debounce
;
65 struct gpio_desc
*gpiod
;
66 const struct gpio_keys_button
*b
;
69 extern u64
uevent_next_seqnum(void);
71 #define BH_MAP(_code, _name) \
77 static struct bh_map button_map
[] = {
78 BH_MAP(BTN_0
, "BTN_0"),
79 BH_MAP(BTN_1
, "BTN_1"),
80 BH_MAP(BTN_2
, "BTN_2"),
81 BH_MAP(BTN_3
, "BTN_3"),
82 BH_MAP(BTN_4
, "BTN_4"),
83 BH_MAP(BTN_5
, "BTN_5"),
84 BH_MAP(BTN_6
, "BTN_6"),
85 BH_MAP(BTN_7
, "BTN_7"),
86 BH_MAP(BTN_8
, "BTN_8"),
87 BH_MAP(BTN_9
, "BTN_9"),
88 BH_MAP(KEY_BRIGHTNESS_ZERO
, "brightness_zero"),
89 BH_MAP(KEY_CONFIG
, "config"),
90 BH_MAP(KEY_COPY
, "copy"),
91 BH_MAP(KEY_EJECTCD
, "eject"),
92 BH_MAP(KEY_HELP
, "help"),
93 BH_MAP(KEY_LIGHTS_TOGGLE
, "lights_toggle"),
94 BH_MAP(KEY_PHONE
, "phone"),
95 BH_MAP(KEY_POWER
, "power"),
96 BH_MAP(KEY_POWER2
, "reboot"),
97 BH_MAP(KEY_RESTART
, "reset"),
98 BH_MAP(KEY_RFKILL
, "rfkill"),
99 BH_MAP(KEY_VIDEO
, "video"),
100 BH_MAP(KEY_WIMAX
, "wwan"),
101 BH_MAP(KEY_WLAN
, "wlan"),
102 BH_MAP(KEY_WPS_BUTTON
, "wps"),
105 /* -------------------------------------------------------------------------*/
107 static __printf(3, 4)
108 int bh_event_add_var(struct bh_event
*event
, int argv
, const char *format
, ...)
110 static char buf
[128];
118 va_start(args
, format
);
119 len
= vsnprintf(buf
, sizeof(buf
), format
, args
);
122 if (len
>= sizeof(buf
)) {
123 WARN(1, "buffer size too small");
127 s
= skb_put(event
->skb
, len
+ 1);
130 pr_debug(PFX
"added variable '%s'\n", s
);
135 static int button_hotplug_fill_event(struct bh_event
*event
)
139 ret
= bh_event_add_var(event
, 0, "HOME=%s", "/");
143 ret
= bh_event_add_var(event
, 0, "PATH=%s",
144 "/sbin:/bin:/usr/sbin:/usr/bin");
148 ret
= bh_event_add_var(event
, 0, "SUBSYSTEM=%s", "button");
152 ret
= bh_event_add_var(event
, 0, "ACTION=%s", event
->action
);
156 ret
= bh_event_add_var(event
, 0, "BUTTON=%s", event
->name
);
160 if (event
->type
== EV_SW
) {
161 ret
= bh_event_add_var(event
, 0, "TYPE=%s", "switch");
166 ret
= bh_event_add_var(event
, 0, "SEEN=%ld", event
->seen
);
170 ret
= bh_event_add_var(event
, 0, "SEQNUM=%llu", uevent_next_seqnum());
175 static void button_hotplug_work(struct work_struct
*work
)
177 struct bh_event
*event
= container_of(work
, struct bh_event
, work
);
180 event
->skb
= alloc_skb(BH_SKB_SIZE
, GFP_KERNEL
);
184 ret
= bh_event_add_var(event
, 0, "%s@", event
->action
);
188 ret
= button_hotplug_fill_event(event
);
192 NETLINK_CB(event
->skb
).dst_group
= 1;
193 broadcast_uevent(event
->skb
, 0, 1, GFP_KERNEL
);
197 pr_err(PFX
"work error %d\n", ret
);
198 kfree_skb(event
->skb
);
204 static int button_hotplug_create_event(const char *name
, unsigned int type
,
205 unsigned long seen
, int pressed
)
207 struct bh_event
*event
;
209 pr_debug(PFX
"create event, name=%s, seen=%lu, pressed=%d\n",
210 name
, seen
, pressed
);
212 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
219 event
->action
= pressed
? "pressed" : "released";
221 INIT_WORK(&event
->work
, (void *)(void *)button_hotplug_work
);
222 schedule_work(&event
->work
);
227 /* -------------------------------------------------------------------------*/
229 static int button_get_index(unsigned int code
)
233 for (i
= 0; i
< ARRAY_SIZE(button_map
); i
++)
234 if (button_map
[i
].code
== code
)
240 static void button_hotplug_event(struct gpio_keys_button_data
*data
,
241 unsigned int type
, int value
)
243 struct bh_priv
*priv
= &data
->bh
;
244 unsigned long seen
= jiffies
;
247 pr_debug(PFX
"event type=%u, code=%u, value=%d\n", type
, data
->b
->code
, value
);
249 if ((type
!= EV_KEY
) && (type
!= EV_SW
))
252 btn
= button_get_index(data
->b
->code
);
256 button_hotplug_create_event(button_map
[btn
].name
, type
,
257 (seen
- priv
->seen
) / HZ
, value
);
261 struct gpio_keys_button_dev
{
263 struct delayed_work work
;
266 struct gpio_keys_platform_data
*pdata
;
267 struct gpio_keys_button_data data
[0];
270 static int gpio_button_get_value(struct gpio_keys_button_data
*bdata
)
274 if (bdata
->can_sleep
)
275 val
= !!gpio_get_value_cansleep(bdata
->b
->gpio
);
277 val
= !!gpio_get_value(bdata
->b
->gpio
);
279 return val
^ bdata
->b
->active_low
;
282 static void gpio_keys_polled_check_state(struct gpio_keys_button_data
*bdata
)
284 int state
= gpio_button_get_value(bdata
);
286 if (state
!= bdata
->last_state
) {
287 unsigned int type
= bdata
->b
->type
?: EV_KEY
;
289 if (bdata
->count
< bdata
->threshold
) {
294 if (bdata
->last_state
!= -1 || type
== EV_SW
)
295 button_hotplug_event(bdata
, type
, state
);
297 bdata
->last_state
= state
;
303 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev
*bdev
)
305 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
306 unsigned long delay
= msecs_to_jiffies(pdata
->poll_interval
);
309 delay
= round_jiffies_relative(delay
);
310 schedule_delayed_work(&bdev
->work
, delay
);
313 static void gpio_keys_polled_poll(struct work_struct
*work
)
315 struct gpio_keys_button_dev
*bdev
=
316 container_of(work
, struct gpio_keys_button_dev
, work
.work
);
319 for (i
= 0; i
< bdev
->pdata
->nbuttons
; i
++) {
320 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
321 gpio_keys_polled_check_state(bdata
);
323 gpio_keys_polled_queue_work(bdev
);
326 static void gpio_keys_polled_close(struct gpio_keys_button_dev
*bdev
)
328 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
330 cancel_delayed_work_sync(&bdev
->work
);
333 pdata
->disable(bdev
->dev
);
336 static void gpio_keys_irq_work_func(struct work_struct
*work
)
338 struct gpio_keys_button_data
*bdata
= container_of(work
,
339 struct gpio_keys_button_data
, work
.work
);
340 int state
= gpio_button_get_value(bdata
);
342 if (state
!= bdata
->last_state
) {
343 unsigned int type
= bdata
->b
->type
?: EV_KEY
;
345 if (bdata
->last_state
!= -1 || type
== EV_SW
)
346 button_hotplug_event(bdata
, type
, state
);
348 bdata
->last_state
= state
;
352 static irqreturn_t
button_handle_irq(int irq
, void *_bdata
)
354 struct gpio_keys_button_data
*bdata
=
355 (struct gpio_keys_button_data
*) _bdata
;
357 schedule_delayed_work(&bdata
->work
,
358 msecs_to_jiffies(bdata
->software_debounce
));
364 static struct gpio_keys_platform_data
*
365 gpio_keys_get_devtree_pdata(struct device
*dev
)
367 struct device_node
*node
, *pp
;
368 struct gpio_keys_platform_data
*pdata
;
369 struct gpio_keys_button
*button
;
378 nbuttons
= of_get_child_count(node
);
382 pdata
= devm_kzalloc(dev
, sizeof(*pdata
) + nbuttons
* (sizeof *button
),
389 pdata
->buttons
= (struct gpio_keys_button
*)(pdata
+ 1);
390 pdata
->nbuttons
= nbuttons
;
392 pdata
->rep
= !!of_get_property(node
, "autorepeat", NULL
);
393 of_property_read_u32(node
, "poll-interval", &pdata
->poll_interval
);
395 for_each_child_of_node(node
, pp
) {
396 enum of_gpio_flags flags
;
398 if (!of_find_property(pp
, "gpios", NULL
)) {
400 dev_warn(dev
, "Found button without gpios\n");
404 button
= (struct gpio_keys_button
*)(&pdata
->buttons
[i
++]);
406 button
->irq
= irq_of_parse_and_map(pp
, 0);
408 button
->gpio
= of_get_gpio_flags(pp
, 0, &flags
);
409 if (button
->gpio
< 0) {
410 error
= button
->gpio
;
411 if (error
!= -ENOENT
) {
412 if (error
!= -EPROBE_DEFER
)
414 "Failed to get gpio flags, error: %d\n",
416 return ERR_PTR(error
);
419 button
->active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
422 if (of_property_read_u32(pp
, "linux,code", &button
->code
)) {
423 dev_err(dev
, "Button without keycode: 0x%x\n",
429 button
->desc
= of_get_property(pp
, "label", NULL
);
431 if (of_property_read_u32(pp
, "linux,input-type", &button
->type
))
432 button
->type
= EV_KEY
;
434 button
->wakeup
= !!of_get_property(pp
, "gpio-key,wakeup", NULL
);
436 if (of_property_read_u32(pp
, "debounce-interval",
437 &button
->debounce_interval
))
438 button
->debounce_interval
= 5;
441 if (pdata
->nbuttons
== 0) {
449 return ERR_PTR(error
);
452 static struct of_device_id gpio_keys_of_match
[] = {
453 { .compatible
= "gpio-keys", },
456 MODULE_DEVICE_TABLE(of
, gpio_keys_of_match
);
458 static struct of_device_id gpio_keys_polled_of_match
[] = {
459 { .compatible
= "gpio-keys-polled", },
462 MODULE_DEVICE_TABLE(of
, gpio_keys_polled_of_match
);
466 static inline struct gpio_keys_platform_data
*
467 gpio_keys_get_devtree_pdata(struct device
*dev
)
473 static int gpio_keys_button_probe(struct platform_device
*pdev
,
474 struct gpio_keys_button_dev
**_bdev
, int polled
)
476 struct gpio_keys_platform_data
*pdata
= pdev
->dev
.platform_data
;
477 struct device
*dev
= &pdev
->dev
;
478 struct gpio_keys_button_dev
*bdev
;
479 struct gpio_keys_button
*buttons
;
484 pdata
= gpio_keys_get_devtree_pdata(dev
);
486 return PTR_ERR(pdata
);
488 dev_err(dev
, "missing platform data\n");
493 if (polled
&& !pdata
->poll_interval
) {
494 dev_err(dev
, "missing poll_interval value\n");
498 buttons
= devm_kzalloc(dev
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
),
501 dev_err(dev
, "no memory for button data\n");
504 memcpy(buttons
, pdata
->buttons
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
));
506 bdev
= devm_kzalloc(dev
, sizeof(struct gpio_keys_button_dev
) +
507 pdata
->nbuttons
* sizeof(struct gpio_keys_button_data
),
510 dev_err(dev
, "no memory for private data\n");
514 bdev
->polled
= polled
;
516 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
517 struct gpio_keys_button
*button
= &buttons
[i
];
518 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
519 unsigned int gpio
= button
->gpio
;
521 if (button
->wakeup
) {
522 dev_err(dev
, DRV_NAME
"does not support wakeup\n");
526 error
= devm_gpio_request(dev
, gpio
,
527 button
->desc
? button
->desc
: DRV_NAME
);
529 dev_err(dev
, "unable to claim gpio %u, err=%d\n",
533 bdata
->gpiod
= gpio_to_desc(gpio
);
537 error
= gpio_direction_input(gpio
);
540 "unable to set direction on gpio %u, err=%d\n",
545 bdata
->can_sleep
= gpio_cansleep(gpio
);
546 bdata
->last_state
= -1;
549 bdata
->threshold
= DIV_ROUND_UP(button
->debounce_interval
,
550 pdata
->poll_interval
);
552 bdata
->threshold
= 1;
554 if (button
->debounce_interval
) {
555 error
= gpiod_set_debounce(bdata
->gpiod
,
556 button
->debounce_interval
* 1000);
558 * use timer if gpiolib doesn't provide
562 bdata
->software_debounce
=
563 button
->debounce_interval
;
568 bdata
->b
= &pdata
->buttons
[i
];
571 bdev
->dev
= &pdev
->dev
;
573 platform_set_drvdata(pdev
, bdev
);
580 static int gpio_keys_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
, 0);
593 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
594 const struct gpio_keys_button
*button
= &pdata
->buttons
[i
];
595 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
596 unsigned long irqflags
= IRQF_ONESHOT
;
599 bdata
->irq
= gpio_to_irq(button
->gpio
);
601 if (bdata
->irq
< 0) {
602 dev_err(&pdev
->dev
, "failed to get irq for gpio:%d\n",
607 irqflags
|= IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING
;
609 bdata
->irq
= button
->irq
;
612 INIT_DELAYED_WORK(&bdata
->work
, gpio_keys_irq_work_func
);
614 ret
= devm_request_threaded_irq(&pdev
->dev
,
615 bdata
->irq
, NULL
, button_handle_irq
,
616 irqflags
, dev_name(&pdev
->dev
), bdata
);
620 dev_err(&pdev
->dev
, "failed to request irq:%d for gpio:%d\n",
621 bdata
->irq
, button
->gpio
);
624 dev_dbg(&pdev
->dev
, "gpio:%d has irq:%d\n",
625 button
->gpio
, bdata
->irq
);
628 if (bdata
->b
->type
== EV_SW
)
629 button_hotplug_event(bdata
, EV_SW
, gpio_button_get_value(bdata
));
635 static int gpio_keys_polled_probe(struct platform_device
*pdev
)
637 struct gpio_keys_platform_data
*pdata
;
638 struct gpio_keys_button_dev
*bdev
;
642 ret
= gpio_keys_button_probe(pdev
, &bdev
, 1);
647 INIT_DELAYED_WORK(&bdev
->work
, gpio_keys_polled_poll
);
652 pdata
->enable(bdev
->dev
);
654 for (i
= 0; i
< pdata
->nbuttons
; i
++)
655 gpio_keys_polled_check_state(&bdev
->data
[i
]);
657 gpio_keys_polled_queue_work(bdev
);
662 static void gpio_keys_irq_close(struct gpio_keys_button_dev
*bdev
)
664 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
667 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
668 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
670 disable_irq(bdata
->irq
);
671 cancel_delayed_work_sync(&bdata
->work
);
675 static int gpio_keys_remove(struct platform_device
*pdev
)
677 struct gpio_keys_button_dev
*bdev
= platform_get_drvdata(pdev
);
679 platform_set_drvdata(pdev
, NULL
);
682 gpio_keys_polled_close(bdev
);
684 gpio_keys_irq_close(bdev
);
689 static struct platform_driver gpio_keys_driver
= {
690 .probe
= gpio_keys_probe
,
691 .remove
= gpio_keys_remove
,
694 .owner
= THIS_MODULE
,
695 .of_match_table
= of_match_ptr(gpio_keys_of_match
),
699 static struct platform_driver gpio_keys_polled_driver
= {
700 .probe
= gpio_keys_polled_probe
,
701 .remove
= gpio_keys_remove
,
703 .name
= "gpio-keys-polled",
704 .owner
= THIS_MODULE
,
705 .of_match_table
= of_match_ptr(gpio_keys_polled_of_match
),
709 static int __init
gpio_button_init(void)
713 ret
= platform_driver_register(&gpio_keys_driver
);
717 ret
= platform_driver_register(&gpio_keys_polled_driver
);
719 platform_driver_unregister(&gpio_keys_driver
);
724 static void __exit
gpio_button_exit(void)
726 platform_driver_unregister(&gpio_keys_driver
);
727 platform_driver_unregister(&gpio_keys_polled_driver
);
730 module_init(gpio_button_init
);
731 module_exit(gpio_button_exit
);
733 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
734 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
735 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
736 MODULE_LICENSE("GPL v2");
737 MODULE_ALIAS("platform:" DRV_NAME
);