4 * Copyright 2005-2006 Openedhand Ltd.
6 * Author: Richard Purdie <rpurdie@openedhand.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
14 #include <linux/kernel.h>
15 #include <linux/leds.h>
16 #include <linux/list.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/rwsem.h>
22 DECLARE_RWSEM(leds_list_lock
);
23 EXPORT_SYMBOL_GPL(leds_list_lock
);
26 EXPORT_SYMBOL_GPL(leds_list
);
28 static void led_timer_function(unsigned long data
)
30 struct led_classdev
*led_cdev
= (void *)data
;
31 unsigned long brightness
;
34 if (!led_cdev
->blink_delay_on
|| !led_cdev
->blink_delay_off
) {
35 led_set_brightness_nosleep(led_cdev
, LED_OFF
);
39 if (led_cdev
->flags
& LED_BLINK_ONESHOT_STOP
) {
40 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
44 brightness
= led_get_brightness(led_cdev
);
46 /* Time to switch the LED on. */
47 brightness
= led_cdev
->blink_brightness
;
48 delay
= led_cdev
->blink_delay_on
;
50 /* Store the current brightness value to be able
51 * to restore it when the delay_off period is over.
52 * Do it only if there is no pending blink brightness
53 * change, to avoid overwriting the new value.
55 if (!(led_cdev
->flags
& LED_BLINK_BRIGHTNESS_CHANGE
))
56 led_cdev
->blink_brightness
= brightness
;
58 led_cdev
->flags
&= ~LED_BLINK_BRIGHTNESS_CHANGE
;
60 delay
= led_cdev
->blink_delay_off
;
63 led_set_brightness_nosleep(led_cdev
, brightness
);
65 /* Return in next iteration if led is in one-shot mode and we are in
66 * the final blink state so that the led is toggled each delay_on +
67 * delay_off milliseconds in worst case.
69 if (led_cdev
->flags
& LED_BLINK_ONESHOT
) {
70 if (led_cdev
->flags
& LED_BLINK_INVERT
) {
72 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
75 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
79 mod_timer(&led_cdev
->blink_timer
, jiffies
+ msecs_to_jiffies(delay
));
82 static void set_brightness_delayed(struct work_struct
*ws
)
84 struct led_classdev
*led_cdev
=
85 container_of(ws
, struct led_classdev
, set_brightness_work
);
88 if (led_cdev
->flags
& LED_BLINK_DISABLE
) {
89 led_cdev
->delayed_set_value
= LED_OFF
;
90 led_stop_software_blink(led_cdev
);
91 led_cdev
->flags
&= ~LED_BLINK_DISABLE
;
94 if (led_cdev
->brightness_set
)
95 led_cdev
->brightness_set(led_cdev
, led_cdev
->delayed_set_value
);
96 else if (led_cdev
->brightness_set_blocking
)
97 ret
= led_cdev
->brightness_set_blocking(led_cdev
,
98 led_cdev
->delayed_set_value
);
102 dev_err(led_cdev
->dev
,
103 "Setting an LED's brightness failed (%d)\n", ret
);
106 static void led_set_software_blink(struct led_classdev
*led_cdev
,
107 unsigned long delay_on
,
108 unsigned long delay_off
)
110 int current_brightness
;
112 current_brightness
= led_get_brightness(led_cdev
);
113 if (current_brightness
)
114 led_cdev
->blink_brightness
= current_brightness
;
115 if (!led_cdev
->blink_brightness
)
116 led_cdev
->blink_brightness
= led_cdev
->max_brightness
;
118 led_cdev
->blink_delay_on
= delay_on
;
119 led_cdev
->blink_delay_off
= delay_off
;
121 /* never on - just set to off */
123 led_set_brightness_nosleep(led_cdev
, LED_OFF
);
127 /* never off - just set to brightness */
129 led_set_brightness_nosleep(led_cdev
,
130 led_cdev
->blink_brightness
);
134 mod_timer(&led_cdev
->blink_timer
, jiffies
+ 1);
138 static void led_blink_setup(struct led_classdev
*led_cdev
,
139 unsigned long *delay_on
,
140 unsigned long *delay_off
)
142 if (!(led_cdev
->flags
& LED_BLINK_ONESHOT
) &&
143 led_cdev
->blink_set
&&
144 !led_cdev
->blink_set(led_cdev
, delay_on
, delay_off
))
147 /* blink with 1 Hz as default if nothing specified */
148 if (!*delay_on
&& !*delay_off
)
149 *delay_on
= *delay_off
= 500;
151 led_set_software_blink(led_cdev
, *delay_on
, *delay_off
);
154 void led_init_core(struct led_classdev
*led_cdev
)
156 INIT_WORK(&led_cdev
->set_brightness_work
, set_brightness_delayed
);
158 setup_timer(&led_cdev
->blink_timer
, led_timer_function
,
159 (unsigned long)led_cdev
);
161 EXPORT_SYMBOL_GPL(led_init_core
);
163 void led_blink_set(struct led_classdev
*led_cdev
,
164 unsigned long *delay_on
,
165 unsigned long *delay_off
)
167 del_timer_sync(&led_cdev
->blink_timer
);
169 led_cdev
->flags
&= ~LED_BLINK_ONESHOT
;
170 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
172 led_blink_setup(led_cdev
, delay_on
, delay_off
);
174 EXPORT_SYMBOL_GPL(led_blink_set
);
176 void led_blink_set_oneshot(struct led_classdev
*led_cdev
,
177 unsigned long *delay_on
,
178 unsigned long *delay_off
,
181 if ((led_cdev
->flags
& LED_BLINK_ONESHOT
) &&
182 timer_pending(&led_cdev
->blink_timer
))
185 led_cdev
->flags
|= LED_BLINK_ONESHOT
;
186 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
189 led_cdev
->flags
|= LED_BLINK_INVERT
;
191 led_cdev
->flags
&= ~LED_BLINK_INVERT
;
193 led_blink_setup(led_cdev
, delay_on
, delay_off
);
195 EXPORT_SYMBOL_GPL(led_blink_set_oneshot
);
197 void led_stop_software_blink(struct led_classdev
*led_cdev
)
199 del_timer_sync(&led_cdev
->blink_timer
);
200 led_cdev
->blink_delay_on
= 0;
201 led_cdev
->blink_delay_off
= 0;
203 EXPORT_SYMBOL_GPL(led_stop_software_blink
);
205 void led_set_brightness(struct led_classdev
*led_cdev
,
206 enum led_brightness brightness
)
209 * In case blinking is on delay brightness setting
210 * until the next timer tick.
212 if (led_cdev
->blink_delay_on
|| led_cdev
->blink_delay_off
) {
214 * If we need to disable soft blinking delegate this to the
215 * work queue task to avoid problems in case we are called
216 * from hard irq context.
218 if (brightness
== LED_OFF
) {
219 led_cdev
->flags
|= LED_BLINK_DISABLE
;
220 schedule_work(&led_cdev
->set_brightness_work
);
222 led_cdev
->flags
|= LED_BLINK_BRIGHTNESS_CHANGE
;
223 led_cdev
->blink_brightness
= brightness
;
228 led_set_brightness_nosleep(led_cdev
, brightness
);
230 EXPORT_SYMBOL_GPL(led_set_brightness
);
232 void led_set_brightness_nopm(struct led_classdev
*led_cdev
,
233 enum led_brightness value
)
235 /* Use brightness_set op if available, it is guaranteed not to sleep */
236 if (led_cdev
->brightness_set
) {
237 led_cdev
->brightness_set(led_cdev
, value
);
241 /* If brightness setting can sleep, delegate it to a work queue task */
242 led_cdev
->delayed_set_value
= value
;
243 schedule_work(&led_cdev
->set_brightness_work
);
245 EXPORT_SYMBOL_GPL(led_set_brightness_nopm
);
247 void led_set_brightness_nosleep(struct led_classdev
*led_cdev
,
248 enum led_brightness value
)
250 led_cdev
->brightness
= min(value
, led_cdev
->max_brightness
);
252 if (led_cdev
->flags
& LED_SUSPENDED
)
255 led_set_brightness_nopm(led_cdev
, led_cdev
->brightness
);
257 EXPORT_SYMBOL_GPL(led_set_brightness_nosleep
);
259 int led_set_brightness_sync(struct led_classdev
*led_cdev
,
260 enum led_brightness value
)
262 if (led_cdev
->blink_delay_on
|| led_cdev
->blink_delay_off
)
265 led_cdev
->brightness
= min(value
, led_cdev
->max_brightness
);
267 if (led_cdev
->flags
& LED_SUSPENDED
)
270 if (led_cdev
->brightness_set_blocking
)
271 return led_cdev
->brightness_set_blocking(led_cdev
,
272 led_cdev
->brightness
);
275 EXPORT_SYMBOL_GPL(led_set_brightness_sync
);
277 int led_update_brightness(struct led_classdev
*led_cdev
)
281 if (led_cdev
->brightness_get
) {
282 ret
= led_cdev
->brightness_get(led_cdev
);
284 led_cdev
->brightness
= ret
;
291 EXPORT_SYMBOL_GPL(led_update_brightness
);
293 /* Caller must ensure led_cdev->led_access held */
294 void led_sysfs_disable(struct led_classdev
*led_cdev
)
296 lockdep_assert_held(&led_cdev
->led_access
);
298 led_cdev
->flags
|= LED_SYSFS_DISABLE
;
300 EXPORT_SYMBOL_GPL(led_sysfs_disable
);
302 /* Caller must ensure led_cdev->led_access held */
303 void led_sysfs_enable(struct led_classdev
*led_cdev
)
305 lockdep_assert_held(&led_cdev
->led_access
);
307 led_cdev
->flags
&= ~LED_SYSFS_DISABLE
;
309 EXPORT_SYMBOL_GPL(led_sysfs_enable
);