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/platform_device.h>
27 #include <linux/of_gpio.h>
28 #include <linux/gpio_keys.h>
30 #define DRV_NAME "gpio-keys-polled"
32 #define BH_SKB_SIZE 2048
34 #define PFX DRV_NAME ": "
39 #define BH_DBG(fmt, args...) printk(KERN_DEBUG "%s: " fmt, DRV_NAME, ##args )
41 #define BH_DBG(fmt, args...) do {} while (0)
44 #define BH_ERR(fmt, args...) printk(KERN_ERR "%s: " fmt, DRV_NAME, ##args )
56 struct work_struct work
;
64 struct gpio_keys_button_data
{
65 struct delayed_work work
;
73 extern u64
uevent_next_seqnum(void);
75 #define BH_MAP(_code, _name) \
81 static struct bh_map button_map
[] = {
82 BH_MAP(BTN_0
, "BTN_0"),
83 BH_MAP(BTN_1
, "BTN_1"),
84 BH_MAP(BTN_2
, "BTN_2"),
85 BH_MAP(BTN_3
, "BTN_3"),
86 BH_MAP(BTN_4
, "BTN_4"),
87 BH_MAP(BTN_5
, "BTN_5"),
88 BH_MAP(BTN_6
, "BTN_6"),
89 BH_MAP(BTN_7
, "BTN_7"),
90 BH_MAP(BTN_8
, "BTN_8"),
91 BH_MAP(BTN_9
, "BTN_9"),
92 BH_MAP(KEY_RESTART
, "reset"),
93 BH_MAP(KEY_RFKILL
, "rfkill"),
95 BH_MAP(KEY_WPS_BUTTON
, "wps"),
96 #endif /* KEY_WPS_BUTTON */
99 /* -------------------------------------------------------------------------*/
101 static int bh_event_add_var(struct bh_event
*event
, int argv
,
102 const char *format
, ...)
104 static char buf
[128];
112 va_start(args
, format
);
113 len
= vsnprintf(buf
, sizeof(buf
), format
, args
);
116 if (len
>= sizeof(buf
)) {
117 BH_ERR("buffer size too small\n");
122 s
= skb_put(event
->skb
, len
+ 1);
125 BH_DBG("added variable '%s'\n", s
);
130 static int button_hotplug_fill_event(struct bh_event
*event
)
134 ret
= bh_event_add_var(event
, 0, "HOME=%s", "/");
138 ret
= bh_event_add_var(event
, 0, "PATH=%s",
139 "/sbin:/bin:/usr/sbin:/usr/bin");
143 ret
= bh_event_add_var(event
, 0, "SUBSYSTEM=%s", "button");
147 ret
= bh_event_add_var(event
, 0, "ACTION=%s", event
->action
);
151 ret
= bh_event_add_var(event
, 0, "BUTTON=%s", event
->name
);
155 ret
= bh_event_add_var(event
, 0, "SEEN=%ld", event
->seen
);
159 ret
= bh_event_add_var(event
, 0, "SEQNUM=%llu", uevent_next_seqnum());
164 static void button_hotplug_work(struct work_struct
*work
)
166 struct bh_event
*event
= container_of(work
, struct bh_event
, work
);
169 event
->skb
= alloc_skb(BH_SKB_SIZE
, GFP_KERNEL
);
173 ret
= bh_event_add_var(event
, 0, "%s@", event
->action
);
177 ret
= button_hotplug_fill_event(event
);
181 NETLINK_CB(event
->skb
).dst_group
= 1;
182 broadcast_uevent(event
->skb
, 0, 1, GFP_KERNEL
);
186 BH_ERR("work error %d\n", ret
);
187 kfree_skb(event
->skb
);
193 static int button_hotplug_create_event(const char *name
, unsigned long seen
,
196 struct bh_event
*event
;
198 BH_DBG("create event, name=%s, seen=%lu, pressed=%d\n",
199 name
, seen
, pressed
);
201 event
= kzalloc(sizeof(*event
), GFP_KERNEL
);
207 event
->action
= pressed
? "pressed" : "released";
209 INIT_WORK(&event
->work
, (void *)(void *)button_hotplug_work
);
210 schedule_work(&event
->work
);
215 /* -------------------------------------------------------------------------*/
217 #ifdef CONFIG_HOTPLUG
218 static int button_get_index(unsigned int code
)
222 for (i
= 0; i
< ARRAY_SIZE(button_map
); i
++)
223 if (button_map
[i
].code
== code
)
228 static void button_hotplug_event(struct gpio_keys_button_data
*data
,
229 unsigned int type
, unsigned int code
, int value
)
231 struct bh_priv
*priv
= &data
->bh
;
232 unsigned long seen
= jiffies
;
235 BH_DBG("event type=%u, code=%u, value=%d\n", type
, code
, value
);
240 btn
= button_get_index(code
);
244 button_hotplug_create_event(button_map
[btn
].name
,
245 (seen
- priv
->seen
) / HZ
, value
);
249 static void button_hotplug_event(struct gpio_keys_button_data
*data
,
250 unsigned int type
, unsigned int code
, int value
)
253 #endif /* CONFIG_HOTPLUG */
255 struct gpio_keys_polled_dev
{
256 struct delayed_work work
;
259 struct gpio_keys_platform_data
*pdata
;
260 struct gpio_keys_button_data data
[0];
263 static void gpio_keys_polled_check_state(struct gpio_keys_button
*button
,
264 struct gpio_keys_button_data
*bdata
)
268 if (bdata
->can_sleep
)
269 state
= !!gpio_get_value_cansleep(button
->gpio
);
271 state
= !!gpio_get_value(button
->gpio
);
273 state
= !!(state
^ button
->active_low
);
274 if (state
!= bdata
->last_state
) {
275 unsigned int type
= button
->type
?: EV_KEY
;
277 if (bdata
->count
< bdata
->threshold
) {
282 button_hotplug_event(bdata
, type
, button
->code
, state
);
283 bdata
->last_state
= state
;
289 static void gpio_keys_polled_queue_work(struct gpio_keys_polled_dev
*bdev
)
291 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
292 unsigned long delay
= msecs_to_jiffies(pdata
->poll_interval
);
295 delay
= round_jiffies_relative(delay
);
296 schedule_delayed_work(&bdev
->work
, delay
);
299 static void gpio_keys_polled_poll(struct work_struct
*work
)
301 struct gpio_keys_polled_dev
*bdev
=
302 container_of(work
, struct gpio_keys_polled_dev
, work
.work
);
303 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
306 for (i
= 0; i
< bdev
->pdata
->nbuttons
; i
++) {
307 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
308 gpio_keys_polled_check_state(&pdata
->buttons
[i
], bdata
);
310 gpio_keys_polled_queue_work(bdev
);
313 static void gpio_keys_polled_open(struct gpio_keys_polled_dev
*bdev
)
315 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
319 pdata
->enable(bdev
->dev
);
321 /* report initial state of the buttons */
322 for (i
= 0; i
< pdata
->nbuttons
; i
++)
323 gpio_keys_polled_check_state(&pdata
->buttons
[i
], &bdev
->data
[i
]);
325 gpio_keys_polled_queue_work(bdev
);
329 static struct gpio_keys_platform_data
*
330 gpio_keys_polled_get_devtree_pdata(struct device
*dev
)
332 struct device_node
*node
, *pp
;
333 struct gpio_keys_platform_data
*pdata
;
334 struct gpio_keys_button
*button
;
343 nbuttons
= of_get_child_count(node
);
347 pdata
= kzalloc(sizeof(*pdata
) + nbuttons
* (sizeof *button
),
354 pdata
->buttons
= (struct gpio_keys_button
*)(pdata
+ 1);
355 pdata
->nbuttons
= nbuttons
;
357 pdata
->rep
= !!of_get_property(node
, "autorepeat", NULL
);
358 of_property_read_u32(node
, "poll-interval", &pdata
->poll_interval
);
361 for_each_child_of_node(node
, pp
) {
362 enum of_gpio_flags flags
;
364 if (!of_find_property(pp
, "gpios", NULL
)) {
366 dev_warn(dev
, "Found button without gpios\n");
370 button
= &pdata
->buttons
[i
++];
372 button
->gpio
= of_get_gpio_flags(pp
, 0, &flags
);
373 button
->active_low
= flags
& OF_GPIO_ACTIVE_LOW
;
375 if (of_property_read_u32(pp
, "linux,code", &button
->code
)) {
376 dev_err(dev
, "Button without keycode: 0x%x\n",
382 button
->desc
= of_get_property(pp
, "label", NULL
);
384 if (of_property_read_u32(pp
, "linux,input-type", &button
->type
))
385 button
->type
= EV_KEY
;
387 button
->wakeup
= !!of_get_property(pp
, "gpio-key,wakeup", NULL
);
389 if (of_property_read_u32(pp
, "debounce-interval",
390 &button
->debounce_interval
))
391 button
->debounce_interval
= 5;
394 if (pdata
->nbuttons
== 0) {
404 return ERR_PTR(error
);
407 static struct of_device_id gpio_keys_polled_of_match
[] = {
408 { .compatible
= "gpio-keys-polled", },
411 MODULE_DEVICE_TABLE(of
, gpio_keys_polled_of_match
);
415 static inline struct gpio_keys_platform_data
*
416 gpio_keys_polled_get_devtree_pdata(struct device
*dev
)
422 static void gpio_keys_polled_close(struct gpio_keys_polled_dev
*bdev
)
424 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
426 cancel_delayed_work_sync(&bdev
->work
);
429 pdata
->disable(bdev
->dev
);
432 static int gpio_keys_polled_probe(struct platform_device
*pdev
)
434 struct gpio_keys_platform_data
*pdata
= pdev
->dev
.platform_data
;
435 struct device
*dev
= &pdev
->dev
;
436 struct gpio_keys_polled_dev
*bdev
;
441 pdata
= gpio_keys_polled_get_devtree_pdata(dev
);
443 return PTR_ERR(pdata
);
445 dev_err(dev
, "missing platform data\n");
450 if (!pdata
->poll_interval
) {
451 dev_err(dev
, "missing poll_interval value\n");
456 bdev
= kzalloc(sizeof(struct gpio_keys_polled_dev
) +
457 pdata
->nbuttons
* sizeof(struct gpio_keys_button_data
),
460 dev_err(dev
, "no memory for private data\n");
464 for (i
= 0; i
< pdata
->nbuttons
; i
++) {
465 struct gpio_keys_button
*button
= &pdata
->buttons
[i
];
466 struct gpio_keys_button_data
*bdata
= &bdev
->data
[i
];
467 unsigned int gpio
= button
->gpio
;
469 if (button
->wakeup
) {
470 dev_err(dev
, DRV_NAME
" does not support wakeup\n");
475 error
= gpio_request(gpio
,
476 button
->desc
? button
->desc
: DRV_NAME
);
478 dev_err(dev
, "unable to claim gpio %u, err=%d\n",
483 error
= gpio_direction_input(gpio
);
486 "unable to set direction on gpio %u, err=%d\n",
491 bdata
->can_sleep
= gpio_cansleep(gpio
);
492 bdata
->last_state
= 0;
493 bdata
->threshold
= DIV_ROUND_UP(button
->debounce_interval
,
494 pdata
->poll_interval
);
497 bdev
->dev
= &pdev
->dev
;
499 platform_set_drvdata(pdev
, bdev
);
501 INIT_DELAYED_WORK(&bdev
->work
, gpio_keys_polled_poll
);
503 gpio_keys_polled_open(bdev
);
509 gpio_free(pdata
->buttons
[i
].gpio
);
512 platform_set_drvdata(pdev
, NULL
);
515 /* If we have no platform_data, we allocated pdata dynamically. */
516 if (!dev_get_platdata(&pdev
->dev
))
522 static int gpio_keys_polled_remove(struct platform_device
*pdev
)
524 struct gpio_keys_polled_dev
*bdev
= platform_get_drvdata(pdev
);
525 struct gpio_keys_platform_data
*pdata
= bdev
->pdata
;
526 int i
= pdata
->nbuttons
;
528 gpio_keys_polled_close(bdev
);
531 gpio_free(pdata
->buttons
[i
].gpio
);
534 platform_set_drvdata(pdev
, NULL
);
539 static struct platform_driver gpio_keys_polled_driver
= {
540 .probe
= gpio_keys_polled_probe
,
541 .remove
= gpio_keys_polled_remove
,
544 .owner
= THIS_MODULE
,
545 .of_match_table
= of_match_ptr(gpio_keys_polled_of_match
),
549 static int __init
gpio_keys_polled_init(void)
551 return platform_driver_register(&gpio_keys_polled_driver
);
554 static void __exit
gpio_keys_polled_exit(void)
556 platform_driver_unregister(&gpio_keys_polled_driver
);
559 module_init(gpio_keys_polled_init
);
560 module_exit(gpio_keys_polled_exit
);
562 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
563 MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
564 MODULE_DESCRIPTION("Polled GPIO Buttons hotplug driver");
565 MODULE_LICENSE("GPL v2");
566 MODULE_ALIAS("platform:" DRV_NAME
);