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_POWER
, "power"),
96 BH_MAP(KEY_RESTART
, "reset"),
97 BH_MAP(KEY_RFKILL
, "rfkill"),
98 BH_MAP(KEY_WPS_BUTTON
, "wps"),
99 BH_MAP(KEY_WIMAX
, "wwan"),
102 /* -------------------------------------------------------------------------*/
104 static __printf(3, 4)
105 int bh_event_add_var(struct bh_event
*event
, int argv
, const char *format
, ...)
107 static char buf
[128];
115 va_start(args
, format
);
116 len
= vsnprintf(buf
, sizeof(buf
), format
, args
);
119 if (len
>= sizeof(buf
)) {
120 WARN(1, "buffer size too small");
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 static int button_get_index(unsigned int code
)
230 for (i
= 0; i
< ARRAY_SIZE(button_map
); i
++)
231 if (button_map
[i
].code
== code
)
237 static void button_hotplug_event(struct gpio_keys_button_data
*data
,
238 unsigned int type
, int value
)
240 struct bh_priv
*priv
= &data
->bh
;
241 unsigned long seen
= jiffies
;
244 BH_DBG("event type=%u, code=%u, value=%d\n", type
, data
->b
->code
, value
);
246 if ((type
!= EV_KEY
) && (type
!= EV_SW
))
249 btn
= button_get_index(data
->b
->code
);
253 button_hotplug_create_event(button_map
[btn
].name
, type
,
254 (seen
- priv
->seen
) / HZ
, value
);
258 struct gpio_keys_button_dev
{
260 struct delayed_work work
;
263 struct gpio_keys_platform_data
*pdata
;
264 struct gpio_keys_button_data data
[0];
267 static int gpio_button_get_value(struct gpio_keys_button_data
*bdata
)
271 if (bdata
->can_sleep
)
272 val
= !!gpio_get_value_cansleep(bdata
->b
->gpio
);
274 val
= !!gpio_get_value(bdata
->b
->gpio
);
276 return val
^ bdata
->b
->active_low
;
279 static void gpio_keys_polled_check_state(struct gpio_keys_button_data
*bdata
)
281 int state
= gpio_button_get_value(bdata
);
283 if (state
!= bdata
->last_state
) {
284 unsigned int type
= bdata
->b
->type
?: EV_KEY
;
286 if (bdata
->count
< bdata
->threshold
) {
291 if ((bdata
->last_state
!= -1) || (type
== EV_SW
))
292 button_hotplug_event(bdata
, type
, state
);
294 bdata
->last_state
= state
;
300 static void gpio_keys_polled_queue_work(struct gpio_keys_button_dev
*bdev
)
302 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
303 unsigned long delay
= msecs_to_jiffies(pdata
->poll_interval
);
306 delay
= round_jiffies_relative(delay
);
307 schedule_delayed_work(&bdev
->work
, delay
);
310 static void gpio_keys_polled_poll(struct work_struct
*work
)
312 struct gpio_keys_button_dev
*bdev
=
313 container_of(work
, struct gpio_keys_button_dev
, work
.work
);
316 for (i
= 0; i
< bdev
->pdata
->nbuttons
; i
++) {
317 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
318 gpio_keys_polled_check_state(bdata
);
320 gpio_keys_polled_queue_work(bdev
);
323 static void gpio_keys_polled_close(struct gpio_keys_button_dev
*bdev
)
325 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
327 cancel_delayed_work_sync(&bdev
->work
);
330 pdata
->disable(bdev
->dev
);
333 static irqreturn_t
button_handle_irq(int irq
, void *_bdata
)
335 struct gpio_keys_button_data
*bdata
= (struct gpio_keys_button_data
*) _bdata
;
337 button_hotplug_event(bdata
, bdata
->b
->type
?: EV_KEY
, gpio_button_get_value(bdata
));
343 static struct gpio_keys_platform_data
*
344 gpio_keys_get_devtree_pdata(struct device
*dev
)
346 struct device_node
*node
, *pp
;
347 struct gpio_keys_platform_data
*pdata
;
348 struct gpio_keys_button
*button
;
357 nbuttons
= of_get_child_count(node
);
361 pdata
= devm_kzalloc(dev
, sizeof(*pdata
) + nbuttons
* (sizeof *button
),
368 pdata
->buttons
= (struct gpio_keys_button
*)(pdata
+ 1);
369 pdata
->nbuttons
= nbuttons
;
371 pdata
->rep
= !!of_get_property(node
, "autorepeat", NULL
);
372 of_property_read_u32(node
, "poll-interval", &pdata
->poll_interval
);
374 for_each_child_of_node(node
, pp
) {
375 enum of_gpio_flags flags
;
377 if (!of_find_property(pp
, "gpios", NULL
)) {
379 dev_warn(dev
, "Found button without gpios\n");
383 button
= &pdata
->buttons
[i
++];
385 button
->gpio
= of_get_gpio_flags(pp
, 0, &flags
);
386 if (button
->gpio
< 0) {
387 error
= button
->gpio
;
388 if (error
!= -ENOENT
) {
389 if (error
!= -EPROBE_DEFER
)
391 "Failed to get gpio flags, error: %d\n",
393 return ERR_PTR(error
);
396 button
->active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
399 if (of_property_read_u32(pp
, "linux,code", &button
->code
)) {
400 dev_err(dev
, "Button without keycode: 0x%x\n",
406 button
->desc
= of_get_property(pp
, "label", NULL
);
408 if (of_property_read_u32(pp
, "linux,input-type", &button
->type
))
409 button
->type
= EV_KEY
;
411 button
->wakeup
= !!of_get_property(pp
, "gpio-key,wakeup", NULL
);
413 if (of_property_read_u32(pp
, "debounce-interval",
414 &button
->debounce_interval
))
415 button
->debounce_interval
= 5;
418 if (pdata
->nbuttons
== 0) {
426 return ERR_PTR(error
);
429 static struct of_device_id gpio_keys_of_match
[] = {
430 { .compatible
= "gpio-keys", },
433 MODULE_DEVICE_TABLE(of
, gpio_keys_of_match
);
435 static struct of_device_id gpio_keys_polled_of_match
[] = {
436 { .compatible
= "gpio-keys-polled", },
439 MODULE_DEVICE_TABLE(of
, gpio_keys_polled_of_match
);
443 static inline struct gpio_keys_platform_data
*
444 gpio_keys_get_devtree_pdata(struct device
*dev
)
450 static int gpio_keys_button_probe(struct platform_device
*pdev
,
451 struct gpio_keys_button_dev
**_bdev
, int polled
)
453 struct gpio_keys_platform_data
*pdata
= pdev
->dev
.platform_data
;
454 struct device
*dev
= &pdev
->dev
;
455 struct gpio_keys_button_dev
*bdev
;
456 struct gpio_keys_button
*buttons
;
461 pdata
= gpio_keys_get_devtree_pdata(dev
);
463 return PTR_ERR(pdata
);
465 dev_err(dev
, "missing platform data\n");
468 pdev
->dev
.platform_data
= pdata
;
471 if (polled
&& !pdata
->poll_interval
) {
472 dev_err(dev
, "missing poll_interval value\n");
476 buttons
= devm_kzalloc(dev
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
),
479 dev_err(dev
, "no memory for button data\n");
482 memcpy(buttons
, pdata
->buttons
, pdata
->nbuttons
* sizeof(struct gpio_keys_button
));
484 bdev
= devm_kzalloc(dev
, sizeof(struct gpio_keys_button_dev
) +
485 pdata
->nbuttons
* sizeof(struct gpio_keys_button_data
),
488 dev_err(dev
, "no memory for private data\n");
492 bdev
->polled
= polled
;
494 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
495 struct gpio_keys_button
*button
= &buttons
[i
];
496 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
497 unsigned int gpio
= button
->gpio
;
499 if (button
->wakeup
) {
500 dev_err(dev
, DRV_NAME
"does not support wakeup\n");
504 error
= devm_gpio_request(dev
, gpio
,
505 button
->desc
? button
->desc
: DRV_NAME
);
507 dev_err(dev
, "unable to claim gpio %u, err=%d\n",
512 error
= gpio_direction_input(gpio
);
515 "unable to set direction on gpio %u, err=%d\n",
520 bdata
->can_sleep
= gpio_cansleep(gpio
);
521 bdata
->last_state
= -1;
524 bdata
->threshold
= DIV_ROUND_UP(button
->debounce_interval
,
525 pdata
->poll_interval
);
527 bdata
->threshold
= 1;
529 bdata
->b
= &pdata
->buttons
[i
];
532 bdev
->dev
= &pdev
->dev
;
534 platform_set_drvdata(pdev
, bdev
);
541 static int gpio_keys_probe(struct platform_device
*pdev
)
543 struct gpio_keys_platform_data
*pdata
;
544 struct gpio_keys_button_dev
*bdev
;
548 ret
= gpio_keys_button_probe(pdev
, &bdev
, 0);
553 pdata
= pdev
->dev
.platform_data
;
554 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
555 struct gpio_keys_button
*button
= &pdata
->buttons
[i
];
556 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
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
);
565 ret
= devm_request_threaded_irq(&pdev
->dev
, button
->irq
, NULL
, button_handle_irq
,
566 IRQF_TRIGGER_RISING
| IRQF_TRIGGER_FALLING
| IRQF_ONESHOT
,
567 dev_name(&pdev
->dev
), bdata
);
569 dev_err(&pdev
->dev
, "failed to request irq:%d for gpio:%d\n", button
->irq
, button
->gpio
);
571 dev_dbg(&pdev
->dev
, "gpio:%d has irq:%d\n", button
->gpio
, button
->irq
);
573 if (bdata
->b
->type
== EV_SW
)
574 button_hotplug_event(bdata
, EV_SW
, gpio_button_get_value(bdata
));
580 static int gpio_keys_polled_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
, 1);
592 INIT_DELAYED_WORK(&bdev
->work
, gpio_keys_polled_poll
);
597 pdata
->enable(bdev
->dev
);
599 for (i
= 0; i
< pdata
->nbuttons
; i
++)
600 gpio_keys_polled_check_state(&bdev
->data
[i
]);
602 gpio_keys_polled_queue_work(bdev
);
607 static int gpio_keys_remove(struct platform_device
*pdev
)
609 struct gpio_keys_button_dev
*bdev
= platform_get_drvdata(pdev
);
611 platform_set_drvdata(pdev
, NULL
);
614 gpio_keys_polled_close(bdev
);
619 static struct platform_driver gpio_keys_driver
= {
620 .probe
= gpio_keys_probe
,
621 .remove
= gpio_keys_remove
,
624 .owner
= THIS_MODULE
,
625 .of_match_table
= of_match_ptr(gpio_keys_of_match
),
629 static struct platform_driver gpio_keys_polled_driver
= {
630 .probe
= gpio_keys_polled_probe
,
631 .remove
= gpio_keys_remove
,
633 .name
= "gpio-keys-polled",
634 .owner
= THIS_MODULE
,
635 .of_match_table
= of_match_ptr(gpio_keys_polled_of_match
),
639 static int __init
gpio_button_init(void)
643 ret
= platform_driver_register(&gpio_keys_driver
);
647 ret
= platform_driver_register(&gpio_keys_polled_driver
);
649 platform_driver_unregister(&gpio_keys_driver
);
654 static void __exit
gpio_button_exit(void)
656 platform_driver_unregister(&gpio_keys_driver
);
657 platform_driver_unregister(&gpio_keys_polled_driver
);
660 module_init(gpio_button_init
);
661 module_exit(gpio_button_exit
);
663 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
664 MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
665 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
666 MODULE_LICENSE("GPL v2");
667 MODULE_ALIAS("platform:" DRV_NAME
);