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"),
101 /* -------------------------------------------------------------------------*/
103 static int bh_event_add_var(struct bh_event
*event
, int argv
,
104 const char *format
, ...)
106 static char buf
[128];
114 va_start(args
, format
);
115 len
= vsnprintf(buf
, sizeof(buf
), format
, args
);
118 if (len
>= sizeof(buf
)) {
119 BH_ERR("buffer size too small\n");
124 s
= skb_put(event
->skb
, len
+ 1);
127 BH_DBG("added variable '%s'\n", s
);
132 static int button_hotplug_fill_event(struct bh_event
*event
)
136 ret
= bh_event_add_var(event
, 0, "HOME=%s", "/");
140 ret
= bh_event_add_var(event
, 0, "PATH=%s",
141 "/sbin:/bin:/usr/sbin:/usr/bin");
145 ret
= bh_event_add_var(event
, 0, "SUBSYSTEM=%s", "button");
149 ret
= bh_event_add_var(event
, 0, "ACTION=%s", event
->action
);
153 ret
= bh_event_add_var(event
, 0, "BUTTON=%s", event
->name
);
157 if (event
->type
== EV_SW
) {
158 ret
= bh_event_add_var(event
, 0, "TYPE=%s", "switch");
163 ret
= bh_event_add_var(event
, 0, "SEEN=%ld", event
->seen
);
167 ret
= bh_event_add_var(event
, 0, "SEQNUM=%llu", uevent_next_seqnum());
172 static void button_hotplug_work(struct work_struct
*work
)
174 struct bh_event
*event
= container_of(work
, struct bh_event
, work
);
177 event
->skb
= alloc_skb(BH_SKB_SIZE
, GFP_KERNEL
);
181 ret
= bh_event_add_var(event
, 0, "%s@", event
->action
);
185 ret
= button_hotplug_fill_event(event
);
189 NETLINK_CB(event
->skb
).dst_group
= 1;
190 broadcast_uevent(event
->skb
, 0, 1, GFP_KERNEL
);
194 BH_ERR("work error %d\n", ret
);
195 kfree_skb(event
->skb
);
201 static int button_hotplug_create_event(const char *name
, unsigned int type
,
202 unsigned long seen
, int pressed
)
204 struct bh_event
*event
;
206 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
207 name
, seen
, pressed
);
209 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
216 event
->action
= pressed
? "pressed" : "released";
218 INIT_WORK(&event
->work
, (void *)(void *)button_hotplug_work
);
219 schedule_work(&event
->work
);
224 /* -------------------------------------------------------------------------*/
226 #ifdef CONFIG_HOTPLUG
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 static void button_hotplug_event(struct gpio_keys_button_data
*data
,
260 unsigned int type
, int value
)
263 #endif /* CONFIG_HOTPLUG */
265 struct gpio_keys_button_dev
{
267 struct delayed_work work
;
270 struct gpio_keys_platform_data
*pdata
;
271 struct gpio_keys_button_data data
[0];
274 static int gpio_button_get_value(struct gpio_keys_button_data
*bdata
)
278 if (bdata
->can_sleep
)
279 val
= !!gpio_get_value_cansleep(bdata
->b
->gpio
);
281 val
= !!gpio_get_value(bdata
->b
->gpio
);
283 return val
^ bdata
->b
->active_low
;
286 static void gpio_keys_polled_check_state(struct gpio_keys_button_data
*bdata
)
288 int state
= gpio_button_get_value(bdata
);
290 if (state
!= bdata
->last_state
) {
291 unsigned int type
= bdata
->b
->type
?: EV_KEY
;
293 if (bdata
->count
< bdata
->threshold
) {
298 if ((bdata
->last_state
!= -1) || (type
== EV_SW
))
299 button_hotplug_event(bdata
, type
, state
);
301 bdata
->last_state
= state
;
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
];
325 gpio_keys_polled_check_state(bdata
);
327 gpio_keys_polled_queue_work(bdev
);
330 static void gpio_keys_polled_close(struct gpio_keys_button_dev
*bdev
)
332 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
334 cancel_delayed_work_sync(&bdev
->work
);
337 pdata
->disable(bdev
->dev
);
340 static irqreturn_t
button_handle_irq(int irq
, void *_bdata
)
342 struct gpio_keys_button_data
*bdata
= (struct gpio_keys_button_data
*) _bdata
;
344 button_hotplug_event(bdata
, bdata
->b
->type
?: EV_KEY
, gpio_button_get_value(bdata
));
350 static struct gpio_keys_platform_data
*
351 gpio_keys_get_devtree_pdata(struct device
*dev
)
353 struct device_node
*node
, *pp
;
354 struct gpio_keys_platform_data
*pdata
;
355 struct gpio_keys_button
*button
;
364 nbuttons
= of_get_child_count(node
);
368 pdata
= devm_kzalloc(dev
, sizeof(*pdata
) + nbuttons
* (sizeof *button
),
375 pdata
->buttons
= (struct gpio_keys_button
*)(pdata
+ 1);
376 pdata
->nbuttons
= nbuttons
;
378 pdata
->rep
= !!of_get_property(node
, "autorepeat", NULL
);
379 of_property_read_u32(node
, "poll-interval", &pdata
->poll_interval
);
381 for_each_child_of_node(node
, pp
) {
382 enum of_gpio_flags flags
;
384 if (!of_find_property(pp
, "gpios", NULL
)) {
386 dev_warn(dev
, "Found button without gpios\n");
390 button
= &pdata
->buttons
[i
++];
392 button
->gpio
= of_get_gpio_flags(pp
, 0, &flags
);
393 button
->active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
395 if (of_property_read_u32(pp
, "linux,code", &button
->code
)) {
396 dev_err(dev
, "Button without keycode: 0x%x\n",
402 button
->desc
= of_get_property(pp
, "label", NULL
);
404 if (of_property_read_u32(pp
, "linux,input-type", &button
->type
))
405 button
->type
= EV_KEY
;
407 button
->wakeup
= !!of_get_property(pp
, "gpio-key,wakeup", NULL
);
409 if (of_property_read_u32(pp
, "debounce-interval",
410 &button
->debounce_interval
))
411 button
->debounce_interval
= 5;
414 if (pdata
->nbuttons
== 0) {
422 return ERR_PTR(error
);
425 static struct of_device_id gpio_keys_of_match
[] = {
426 { .compatible
= "gpio-keys", },
429 MODULE_DEVICE_TABLE(of
, gpio_keys_of_match
);
431 static struct of_device_id gpio_keys_polled_of_match
[] = {
432 { .compatible
= "gpio-keys-polled", },
435 MODULE_DEVICE_TABLE(of
, gpio_keys_polled_of_match
);
439 static inline struct gpio_keys_platform_data
*
440 gpio_keys_get_devtree_pdata(struct device
*dev
)
446 static int gpio_keys_button_probe(struct platform_device
*pdev
,
447 struct gpio_keys_button_dev
**_bdev
, int polled
)
449 struct gpio_keys_platform_data
*pdata
= pdev
->dev
.platform_data
;
450 struct device
*dev
= &pdev
->dev
;
451 struct gpio_keys_button_dev
*bdev
;
452 struct gpio_keys_button
*buttons
;
457 pdata
= gpio_keys_get_devtree_pdata(dev
);
459 return PTR_ERR(pdata
);
461 dev_err(dev
, "missing platform data\n");
464 pdev
->dev
.platform_data
= pdata
;
467 if (polled
&& !pdata
->poll_interval
) {
468 dev_err(dev
, "missing poll_interval value\n");
472 buttons
= devm_kzalloc(dev
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
),
475 dev_err(dev
, "no memory for button data\n");
478 memcpy(buttons
, pdata
->buttons
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
));
480 bdev
= devm_kzalloc(dev
, sizeof(struct gpio_keys_button_dev
) +
481 pdata
->nbuttons
* sizeof(struct gpio_keys_button_data
),
484 dev_err(dev
, "no memory for private data\n");
488 bdev
->polled
= polled
;
490 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
491 struct gpio_keys_button
*button
= &buttons
[i
];
492 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
493 unsigned int gpio
= button
->gpio
;
495 if (button
->wakeup
) {
496 dev_err(dev
, DRV_NAME
"does not support wakeup\n");
500 error
= devm_gpio_request(dev
, gpio
,
501 button
->desc
? button
->desc
: DRV_NAME
);
503 dev_err(dev
, "unable to claim gpio %u, err=%d\n",
508 error
= gpio_direction_input(gpio
);
511 "unable to set direction on gpio %u, err=%d\n",
516 bdata
->can_sleep
= gpio_cansleep(gpio
);
517 bdata
->last_state
= -1;
520 bdata
->threshold
= DIV_ROUND_UP(button
->debounce_interval
,
521 pdata
->poll_interval
);
523 bdata
->threshold
= 1;
525 bdata
->b
= &pdata
->buttons
[i
];
528 bdev
->dev
= &pdev
->dev
;
530 platform_set_drvdata(pdev
, bdev
);
537 static int gpio_keys_probe(struct platform_device
*pdev
)
539 struct gpio_keys_platform_data
*pdata
;
540 struct gpio_keys_button_dev
*bdev
;
544 ret
= gpio_keys_button_probe(pdev
, &bdev
, 0);
549 pdata
= pdev
->dev
.platform_data
;
550 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
551 struct gpio_keys_button
*button
= &pdata
->buttons
[i
];
552 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
554 if (bdata
->can_sleep
) {
555 dev_err(&pdev
->dev
, "skipping gpio:%d, it can sleep\n", button
->gpio
);
559 button
->irq
= gpio_to_irq(button
->gpio
);
560 if (button
->irq
< 0) {
561 dev_err(&pdev
->dev
, "failed to get irq for gpio:%d\n", button
->gpio
);
564 ret
= devm_request_irq(&pdev
->dev
, button
->irq
, button_handle_irq
,
565 IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING
,
566 dev_name(&pdev
->dev
), bdata
);
568 dev_err(&pdev
->dev
, "failed to request irq:%d for gpio:%d\n", button
->irq
, button
->gpio
);
570 dev_dbg(&pdev
->dev
, "gpio:%d has irq:%d\n", button
->gpio
, button
->irq
);
572 if (bdata
->b
->type
== EV_SW
)
573 button_hotplug_event(bdata
, EV_SW
, gpio_button_get_value(bdata
));
579 static int gpio_keys_polled_probe(struct platform_device
*pdev
)
581 struct gpio_keys_platform_data
*pdata
;
582 struct gpio_keys_button_dev
*bdev
;
586 ret
= gpio_keys_button_probe(pdev
, &bdev
, 1);
591 INIT_DELAYED_WORK(&bdev
->work
, gpio_keys_polled_poll
);
596 pdata
->enable(bdev
->dev
);
598 for (i
= 0; i
< pdata
->nbuttons
; i
++)
599 gpio_keys_polled_check_state(&bdev
->data
[i
]);
601 gpio_keys_polled_queue_work(bdev
);
606 static int gpio_keys_remove(struct platform_device
*pdev
)
608 struct gpio_keys_button_dev
*bdev
= platform_get_drvdata(pdev
);
610 platform_set_drvdata(pdev
, NULL
);
613 gpio_keys_polled_close(bdev
);
618 static struct platform_driver gpio_keys_driver
= {
619 .probe
= gpio_keys_probe
,
620 .remove
= gpio_keys_remove
,
623 .owner
= THIS_MODULE
,
624 .of_match_table
= of_match_ptr(gpio_keys_of_match
),
628 static struct platform_driver gpio_keys_polled_driver
= {
629 .probe
= gpio_keys_polled_probe
,
630 .remove
= gpio_keys_remove
,
632 .name
= "gpio-keys-polled",
633 .owner
= THIS_MODULE
,
634 .of_match_table
= of_match_ptr(gpio_keys_polled_of_match
),
638 static int __init
gpio_button_init(void)
642 ret
= platform_driver_register(&gpio_keys_driver
);
646 ret
= platform_driver_register(&gpio_keys_polled_driver
);
648 platform_driver_unregister(&gpio_keys_driver
);
653 static void __exit
gpio_button_exit(void)
655 platform_driver_unregister(&gpio_keys_driver
);
656 platform_driver_unregister(&gpio_keys_polled_driver
);
659 module_init(gpio_button_init
);
660 module_exit(gpio_button_exit
);
662 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
663 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
664 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
665 MODULE_LICENSE("GPL v2");
666 MODULE_ALIAS("platform:" DRV_NAME
);