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>
31 #include <linux/gpio/consumer.h>
33 #define BH_SKB_SIZE 2048
35 #define DRV_NAME "gpio-keys"
36 #define PFX DRV_NAME ": "
45 struct work_struct work
;
53 struct gpio_keys_button_data
{
54 struct delayed_work work
;
62 unsigned int software_debounce
;
63 struct gpio_desc
*gpiod
;
64 const struct gpio_keys_button
*b
;
67 extern u64
uevent_next_seqnum(void);
69 #define BH_MAP(_code, _name) \
75 static struct bh_map button_map
[] = {
76 BH_MAP(BTN_0
, "BTN_0"),
77 BH_MAP(BTN_1
, "BTN_1"),
78 BH_MAP(BTN_2
, "BTN_2"),
79 BH_MAP(BTN_3
, "BTN_3"),
80 BH_MAP(BTN_4
, "BTN_4"),
81 BH_MAP(BTN_5
, "BTN_5"),
82 BH_MAP(BTN_6
, "BTN_6"),
83 BH_MAP(BTN_7
, "BTN_7"),
84 BH_MAP(BTN_8
, "BTN_8"),
85 BH_MAP(BTN_9
, "BTN_9"),
86 BH_MAP(KEY_BRIGHTNESS_ZERO
, "brightness_zero"),
87 BH_MAP(KEY_CONFIG
, "config"),
88 BH_MAP(KEY_COPY
, "copy"),
89 BH_MAP(KEY_EJECTCD
, "eject"),
90 BH_MAP(KEY_HELP
, "help"),
91 BH_MAP(KEY_LIGHTS_TOGGLE
, "lights_toggle"),
92 BH_MAP(KEY_PHONE
, "phone"),
93 BH_MAP(KEY_POWER
, "power"),
94 BH_MAP(KEY_POWER2
, "reboot"),
95 BH_MAP(KEY_RESTART
, "reset"),
96 BH_MAP(KEY_RFKILL
, "rfkill"),
97 BH_MAP(KEY_VIDEO
, "video"),
98 BH_MAP(KEY_VOLUMEDOWN
, "volume_down"),
99 BH_MAP(KEY_VOLUMEUP
, "volume_up"),
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
, ...)
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 int gpio_button_get_value(struct gpio_keys_button_data
*bdata
)
244 if (bdata
->can_sleep
)
245 val
= !!gpiod_get_value_cansleep(bdata
->gpiod
);
247 val
= !!gpiod_get_value(bdata
->gpiod
);
252 static void gpio_keys_handle_button(struct gpio_keys_button_data
*bdata
)
254 unsigned int type
= bdata
->b
->type
?: EV_KEY
;
255 int state
= gpio_button_get_value(bdata
);
256 unsigned long seen
= jiffies
;
258 pr_debug(PFX
"event type=%u, code=%u, pressed=%d\n",
259 type
, bdata
->b
->code
, state
);
261 /* is this the initialization state? */
262 if (bdata
->last_state
== -1) {
264 * Don't advertise unpressed buttons on initialization.
265 * Just save their state and continue otherwise this
266 * can cause OpenWrt to enter failsafe.
268 if (type
== EV_KEY
&& state
== 0)
271 * But we are very interested in pressed buttons and
272 * initial switch state. These will be reported to
275 } else if (bdata
->last_state
== state
) {
276 /* reset asserted counter (only relevant for polled keys) */
281 if (bdata
->count
< bdata
->threshold
) {
286 if (bdata
->seen
== 0)
289 button_hotplug_create_event(button_map
[bdata
->map_entry
].name
, type
,
290 (seen
- bdata
->seen
) / HZ
, state
);
294 bdata
->last_state
= state
;
298 struct gpio_keys_button_dev
{
300 struct delayed_work work
;
303 struct gpio_keys_platform_data
*pdata
;
304 struct gpio_keys_button_data data
[0];
307 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev
*bdev
)
309 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
310 unsigned long delay
= msecs_to_jiffies(pdata
->poll_interval
);
313 delay
= round_jiffies_relative(delay
);
314 schedule_delayed_work(&bdev
->work
, delay
);
317 static void gpio_keys_polled_poll(struct work_struct
*work
)
319 struct gpio_keys_button_dev
*bdev
=
320 container_of(work
, struct gpio_keys_button_dev
, work
.work
);
323 for (i
= 0; i
< bdev
->pdata
->nbuttons
; i
++) {
324 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
327 gpio_keys_handle_button(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 void gpio_keys_irq_work_func(struct work_struct
*work
)
344 struct gpio_keys_button_data
*bdata
= container_of(work
,
345 struct gpio_keys_button_data
, work
.work
);
347 gpio_keys_handle_button(bdata
);
350 static irqreturn_t
button_handle_irq(int irq
, void *_bdata
)
352 struct gpio_keys_button_data
*bdata
=
353 (struct gpio_keys_button_data
*) _bdata
;
355 mod_delayed_work(system_wq
, &bdata
->work
,
356 msecs_to_jiffies(bdata
->software_debounce
));
362 static struct gpio_keys_platform_data
*
363 gpio_keys_get_devtree_pdata(struct device
*dev
)
365 struct device_node
*node
, *pp
;
366 struct gpio_keys_platform_data
*pdata
;
367 struct gpio_keys_button
*button
;
375 nbuttons
= of_get_child_count(node
);
377 return ERR_PTR(-EINVAL
);
379 pdata
= devm_kzalloc(dev
, sizeof(*pdata
) + nbuttons
* (sizeof *button
),
382 return ERR_PTR(-ENOMEM
);
384 pdata
->buttons
= (struct gpio_keys_button
*)(pdata
+ 1);
385 pdata
->nbuttons
= nbuttons
;
387 pdata
->rep
= !!of_get_property(node
, "autorepeat", NULL
);
388 of_property_read_u32(node
, "poll-interval", &pdata
->poll_interval
);
390 for_each_child_of_node(node
, pp
) {
391 button
= (struct gpio_keys_button
*)(&pdata
->buttons
[i
++]);
393 if (of_property_read_u32(pp
, "linux,code", &button
->code
)) {
394 dev_err(dev
, "Button node '%s' without keycode\n",
397 return ERR_PTR(-EINVAL
);
400 button
->desc
= of_get_property(pp
, "label", NULL
);
402 if (of_property_read_u32(pp
, "linux,input-type", &button
->type
))
403 button
->type
= EV_KEY
;
405 button
->wakeup
= !!of_get_property(pp
, "gpio-key,wakeup", NULL
);
407 if (of_property_read_u32(pp
, "debounce-interval",
408 &button
->debounce_interval
))
409 button
->debounce_interval
= 5;
411 button
->irq
= irq_of_parse_and_map(pp
, 0);
412 button
->gpio
= -ENOENT
; /* mark this as device-tree */
418 static struct of_device_id gpio_keys_of_match
[] = {
419 { .compatible
= "gpio-keys", },
422 MODULE_DEVICE_TABLE(of
, gpio_keys_of_match
);
424 static struct of_device_id gpio_keys_polled_of_match
[] = {
425 { .compatible
= "gpio-keys-polled", },
428 MODULE_DEVICE_TABLE(of
, gpio_keys_polled_of_match
);
432 static inline struct gpio_keys_platform_data
*
433 gpio_keys_get_devtree_pdata(struct device
*dev
)
439 static int gpio_keys_button_probe(struct platform_device
*pdev
,
440 struct gpio_keys_button_dev
**_bdev
, int polled
)
442 struct device
*dev
= &pdev
->dev
;
443 struct gpio_keys_platform_data
*pdata
= dev_get_platdata(dev
);
444 struct gpio_keys_button_dev
*bdev
;
445 struct gpio_keys_button
*buttons
;
446 struct device_node
*prev
= NULL
;
451 pdata
= gpio_keys_get_devtree_pdata(dev
);
453 return PTR_ERR(pdata
);
455 dev_err(dev
, "missing platform data\n");
460 if (polled
&& !pdata
->poll_interval
) {
461 dev_err(dev
, "missing poll_interval value\n");
465 buttons
= devm_kzalloc(dev
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
),
468 dev_err(dev
, "no memory for button data\n");
471 memcpy(buttons
, pdata
->buttons
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
));
473 bdev
= devm_kzalloc(dev
, sizeof(struct gpio_keys_button_dev
) +
474 pdata
->nbuttons
* sizeof(struct gpio_keys_button_data
),
477 dev_err(dev
, "no memory for private data\n");
481 bdev
->polled
= polled
;
483 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
484 struct gpio_keys_button
*button
= &buttons
[i
];
485 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
486 const char *desc
= button
->desc
? button
->desc
: DRV_NAME
;
488 if (button
->wakeup
) {
489 dev_err(dev
, "does not support wakeup\n");
494 bdata
->map_entry
= button_get_index(button
->code
);
495 if (bdata
->map_entry
< 0) {
496 dev_err(dev
, "does not support key code:%u\n",
502 if (!(button
->type
== 0 || button
->type
== EV_KEY
||
503 button
->type
== EV_SW
)) {
504 dev_err(dev
, "only supports buttons or switches\n");
510 dev_err(dev
, "skipping button %s (only gpio buttons supported)\n",
512 bdata
->b
= &pdata
->buttons
[i
];
516 if (gpio_is_valid(button
->gpio
)) {
517 /* legacy platform data... but is it the lookup table? */
518 bdata
->gpiod
= devm_gpiod_get_index(dev
, desc
, i
,
520 if (IS_ERR(bdata
->gpiod
)) {
521 /* or the legacy (button->gpio is good) way? */
522 error
= devm_gpio_request_one(dev
,
523 button
->gpio
, GPIOF_IN
| (
524 button
->active_low
? GPIOF_ACTIVE_LOW
:
527 if (error
!= -EPROBE_DEFER
) {
528 dev_err(dev
, "unable to claim gpio %d, err=%d\n",
529 button
->gpio
, error
);
534 bdata
->gpiod
= gpio_to_desc(button
->gpio
);
538 struct device_node
*child
=
539 of_get_next_child(dev
->of_node
, prev
);
541 bdata
->gpiod
= devm_gpiod_get_from_of_node(dev
,
542 child
, "gpios", 0, GPIOD_IN
, desc
);
547 if (IS_ERR_OR_NULL(bdata
->gpiod
)) {
548 error
= IS_ERR(bdata
->gpiod
) ? PTR_ERR(bdata
->gpiod
) :
553 bdata
->can_sleep
= gpiod_cansleep(bdata
->gpiod
);
554 bdata
->last_state
= -1; /* Unknown state on boot */
557 bdata
->threshold
= DIV_ROUND_UP(button
->debounce_interval
,
558 pdata
->poll_interval
);
560 /* bdata->threshold = 0; already initialized */
562 if (button
->debounce_interval
) {
563 error
= gpiod_set_debounce(bdata
->gpiod
,
564 button
->debounce_interval
* 1000);
566 * use timer if gpiolib doesn't provide
570 bdata
->software_debounce
=
571 button
->debounce_interval
;
576 bdata
->b
= &pdata
->buttons
[i
];
579 bdev
->dev
= &pdev
->dev
;
581 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
;
597 ret
= gpio_keys_button_probe(pdev
, &bdev
, 0);
602 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
603 const struct gpio_keys_button
*button
= &pdata
->buttons
[i
];
604 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
605 unsigned long irqflags
= IRQF_ONESHOT
;
607 INIT_DELAYED_WORK(&bdata
->work
, gpio_keys_irq_work_func
);
610 bdata
->irq
= gpiod_to_irq(bdata
->gpiod
);
611 if (bdata
->irq
< 0) {
612 dev_err(&pdev
->dev
, "failed to get irq for gpio:%d\n",
617 irqflags
|= IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING
;
619 bdata
->irq
= button
->irq
;
622 schedule_delayed_work(&bdata
->work
,
623 msecs_to_jiffies(bdata
->software_debounce
));
625 ret
= devm_request_threaded_irq(&pdev
->dev
,
626 bdata
->irq
, NULL
, button_handle_irq
,
627 irqflags
, dev_name(&pdev
->dev
), bdata
);
630 dev_err(&pdev
->dev
, "failed to request irq:%d for gpio:%d\n",
631 bdata
->irq
, button
->gpio
);
634 dev_dbg(&pdev
->dev
, "gpio:%d has irq:%d\n",
635 button
->gpio
, bdata
->irq
);
642 static int gpio_keys_polled_probe(struct platform_device
*pdev
)
644 struct gpio_keys_platform_data
*pdata
;
645 struct gpio_keys_button_dev
*bdev
;
648 ret
= gpio_keys_button_probe(pdev
, &bdev
, 1);
652 INIT_DELAYED_WORK(&bdev
->work
, gpio_keys_polled_poll
);
656 pdata
->enable(bdev
->dev
);
658 gpio_keys_polled_queue_work(bdev
);
663 static void gpio_keys_irq_close(struct gpio_keys_button_dev
*bdev
)
665 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
668 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
669 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
671 disable_irq(bdata
->irq
);
672 cancel_delayed_work_sync(&bdata
->work
);
676 static int gpio_keys_remove(struct platform_device
*pdev
)
678 struct gpio_keys_button_dev
*bdev
= platform_get_drvdata(pdev
);
680 platform_set_drvdata(pdev
, NULL
);
683 gpio_keys_polled_close(bdev
);
685 gpio_keys_irq_close(bdev
);
690 static struct platform_driver gpio_keys_driver
= {
691 .probe
= gpio_keys_probe
,
692 .remove
= gpio_keys_remove
,
695 .owner
= THIS_MODULE
,
696 .of_match_table
= of_match_ptr(gpio_keys_of_match
),
700 static struct platform_driver gpio_keys_polled_driver
= {
701 .probe
= gpio_keys_polled_probe
,
702 .remove
= gpio_keys_remove
,
704 .name
= "gpio-keys-polled",
705 .owner
= THIS_MODULE
,
706 .of_match_table
= of_match_ptr(gpio_keys_polled_of_match
),
710 static int __init
gpio_button_init(void)
714 ret
= platform_driver_register(&gpio_keys_driver
);
718 ret
= platform_driver_register(&gpio_keys_polled_driver
);
720 platform_driver_unregister(&gpio_keys_driver
);
725 static void __exit
gpio_button_exit(void)
727 platform_driver_unregister(&gpio_keys_driver
);
728 platform_driver_unregister(&gpio_keys_polled_driver
);
731 module_init(gpio_button_init
);
732 module_exit(gpio_button_exit
);
734 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
735 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
736 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
737 MODULE_LICENSE("GPL v2");
738 MODULE_ALIAS("platform:" DRV_NAME
);