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 int __led_set_brightness(struct led_classdev
*led_cdev
,
29 enum led_brightness value
)
31 if (!led_cdev
->brightness_set
)
34 led_cdev
->brightness_set(led_cdev
, value
);
39 static int __led_set_brightness_blocking(struct led_classdev
*led_cdev
,
40 enum led_brightness value
)
42 if (!led_cdev
->brightness_set_blocking
)
45 return led_cdev
->brightness_set_blocking(led_cdev
, value
);
48 static void led_timer_function(unsigned long data
)
50 struct led_classdev
*led_cdev
= (void *)data
;
51 unsigned long brightness
;
54 if (!led_cdev
->blink_delay_on
|| !led_cdev
->blink_delay_off
) {
55 led_set_brightness_nosleep(led_cdev
, LED_OFF
);
59 if (led_cdev
->flags
& LED_BLINK_ONESHOT_STOP
) {
60 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
64 brightness
= led_get_brightness(led_cdev
);
66 /* Time to switch the LED on. */
67 brightness
= led_cdev
->blink_brightness
;
68 delay
= led_cdev
->blink_delay_on
;
70 /* Store the current brightness value to be able
71 * to restore it when the delay_off period is over.
72 * Do it only if there is no pending blink brightness
73 * change, to avoid overwriting the new value.
75 if (!(led_cdev
->flags
& LED_BLINK_BRIGHTNESS_CHANGE
))
76 led_cdev
->blink_brightness
= brightness
;
78 led_cdev
->flags
&= ~LED_BLINK_BRIGHTNESS_CHANGE
;
80 delay
= led_cdev
->blink_delay_off
;
83 led_set_brightness_nosleep(led_cdev
, brightness
);
85 /* Return in next iteration if led is in one-shot mode and we are in
86 * the final blink state so that the led is toggled each delay_on +
87 * delay_off milliseconds in worst case.
89 if (led_cdev
->flags
& LED_BLINK_ONESHOT
) {
90 if (led_cdev
->flags
& LED_BLINK_INVERT
) {
92 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
95 led_cdev
->flags
|= LED_BLINK_ONESHOT_STOP
;
99 mod_timer(&led_cdev
->blink_timer
, jiffies
+ msecs_to_jiffies(delay
));
102 static void set_brightness_delayed(struct work_struct
*ws
)
104 struct led_classdev
*led_cdev
=
105 container_of(ws
, struct led_classdev
, set_brightness_work
);
108 if (led_cdev
->flags
& LED_BLINK_DISABLE
) {
109 led_cdev
->delayed_set_value
= LED_OFF
;
110 led_stop_software_blink(led_cdev
);
111 led_cdev
->flags
&= ~LED_BLINK_DISABLE
;
114 ret
= __led_set_brightness(led_cdev
, led_cdev
->delayed_set_value
);
115 if (ret
== -ENOTSUPP
)
116 ret
= __led_set_brightness_blocking(led_cdev
,
117 led_cdev
->delayed_set_value
);
119 /* LED HW might have been unplugged, therefore don't warn */
120 !(ret
== -ENODEV
&& (led_cdev
->flags
& LED_UNREGISTERING
) &&
121 (led_cdev
->flags
& LED_HW_PLUGGABLE
)))
122 dev_err(led_cdev
->dev
,
123 "Setting an LED's brightness failed (%d)\n", ret
);
126 static void led_set_software_blink(struct led_classdev
*led_cdev
,
127 unsigned long delay_on
,
128 unsigned long delay_off
)
130 int current_brightness
;
132 current_brightness
= led_get_brightness(led_cdev
);
133 if (current_brightness
)
134 led_cdev
->blink_brightness
= current_brightness
;
135 if (!led_cdev
->blink_brightness
)
136 led_cdev
->blink_brightness
= led_cdev
->max_brightness
;
138 led_cdev
->blink_delay_on
= delay_on
;
139 led_cdev
->blink_delay_off
= delay_off
;
141 /* never on - just set to off */
143 led_set_brightness_nosleep(led_cdev
, LED_OFF
);
147 /* never off - just set to brightness */
149 led_set_brightness_nosleep(led_cdev
,
150 led_cdev
->blink_brightness
);
154 mod_timer(&led_cdev
->blink_timer
, jiffies
+ 1);
158 static void led_blink_setup(struct led_classdev
*led_cdev
,
159 unsigned long *delay_on
,
160 unsigned long *delay_off
)
162 if (!(led_cdev
->flags
& LED_BLINK_ONESHOT
) &&
163 led_cdev
->blink_set
&&
164 !led_cdev
->blink_set(led_cdev
, delay_on
, delay_off
))
167 /* blink with 1 Hz as default if nothing specified */
168 if (!*delay_on
&& !*delay_off
)
169 *delay_on
= *delay_off
= 500;
171 led_set_software_blink(led_cdev
, *delay_on
, *delay_off
);
174 void led_init_core(struct led_classdev
*led_cdev
)
176 INIT_WORK(&led_cdev
->set_brightness_work
, set_brightness_delayed
);
178 setup_timer(&led_cdev
->blink_timer
, led_timer_function
,
179 (unsigned long)led_cdev
);
181 EXPORT_SYMBOL_GPL(led_init_core
);
183 void led_blink_set(struct led_classdev
*led_cdev
,
184 unsigned long *delay_on
,
185 unsigned long *delay_off
)
187 del_timer_sync(&led_cdev
->blink_timer
);
189 led_cdev
->flags
&= ~LED_BLINK_ONESHOT
;
190 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
192 led_blink_setup(led_cdev
, delay_on
, delay_off
);
194 EXPORT_SYMBOL_GPL(led_blink_set
);
196 void led_blink_set_oneshot(struct led_classdev
*led_cdev
,
197 unsigned long *delay_on
,
198 unsigned long *delay_off
,
201 if ((led_cdev
->flags
& LED_BLINK_ONESHOT
) &&
202 timer_pending(&led_cdev
->blink_timer
))
205 led_cdev
->flags
|= LED_BLINK_ONESHOT
;
206 led_cdev
->flags
&= ~LED_BLINK_ONESHOT_STOP
;
209 led_cdev
->flags
|= LED_BLINK_INVERT
;
211 led_cdev
->flags
&= ~LED_BLINK_INVERT
;
213 led_blink_setup(led_cdev
, delay_on
, delay_off
);
215 EXPORT_SYMBOL_GPL(led_blink_set_oneshot
);
217 void led_stop_software_blink(struct led_classdev
*led_cdev
)
219 del_timer_sync(&led_cdev
->blink_timer
);
220 led_cdev
->blink_delay_on
= 0;
221 led_cdev
->blink_delay_off
= 0;
223 EXPORT_SYMBOL_GPL(led_stop_software_blink
);
225 void led_set_brightness(struct led_classdev
*led_cdev
,
226 enum led_brightness brightness
)
229 * In case blinking is on delay brightness setting
230 * until the next timer tick.
232 if (led_cdev
->blink_delay_on
|| led_cdev
->blink_delay_off
) {
234 * If we need to disable soft blinking delegate this to the
235 * work queue task to avoid problems in case we are called
236 * from hard irq context.
238 if (brightness
== LED_OFF
) {
239 led_cdev
->flags
|= LED_BLINK_DISABLE
;
240 schedule_work(&led_cdev
->set_brightness_work
);
242 led_cdev
->flags
|= LED_BLINK_BRIGHTNESS_CHANGE
;
243 led_cdev
->blink_brightness
= brightness
;
248 led_set_brightness_nosleep(led_cdev
, brightness
);
250 EXPORT_SYMBOL_GPL(led_set_brightness
);
252 void led_set_brightness_nopm(struct led_classdev
*led_cdev
,
253 enum led_brightness value
)
255 /* Use brightness_set op if available, it is guaranteed not to sleep */
256 if (!__led_set_brightness(led_cdev
, value
))
259 /* If brightness setting can sleep, delegate it to a work queue task */
260 led_cdev
->delayed_set_value
= value
;
261 schedule_work(&led_cdev
->set_brightness_work
);
263 EXPORT_SYMBOL_GPL(led_set_brightness_nopm
);
265 void led_set_brightness_nosleep(struct led_classdev
*led_cdev
,
266 enum led_brightness value
)
268 led_cdev
->brightness
= min(value
, led_cdev
->max_brightness
);
270 if (led_cdev
->flags
& LED_SUSPENDED
)
273 led_set_brightness_nopm(led_cdev
, led_cdev
->brightness
);
275 EXPORT_SYMBOL_GPL(led_set_brightness_nosleep
);
277 int led_set_brightness_sync(struct led_classdev
*led_cdev
,
278 enum led_brightness value
)
280 if (led_cdev
->blink_delay_on
|| led_cdev
->blink_delay_off
)
283 led_cdev
->brightness
= min(value
, led_cdev
->max_brightness
);
285 if (led_cdev
->flags
& LED_SUSPENDED
)
288 return __led_set_brightness_blocking(led_cdev
, led_cdev
->brightness
);
290 EXPORT_SYMBOL_GPL(led_set_brightness_sync
);
292 int led_update_brightness(struct led_classdev
*led_cdev
)
296 if (led_cdev
->brightness_get
) {
297 ret
= led_cdev
->brightness_get(led_cdev
);
299 led_cdev
->brightness
= ret
;
306 EXPORT_SYMBOL_GPL(led_update_brightness
);
308 /* Caller must ensure led_cdev->led_access held */
309 void led_sysfs_disable(struct led_classdev
*led_cdev
)
311 lockdep_assert_held(&led_cdev
->led_access
);
313 led_cdev
->flags
|= LED_SYSFS_DISABLE
;
315 EXPORT_SYMBOL_GPL(led_sysfs_disable
);
317 /* Caller must ensure led_cdev->led_access held */
318 void led_sysfs_enable(struct led_classdev
*led_cdev
)
320 lockdep_assert_held(&led_cdev
->led_access
);
322 led_cdev
->flags
&= ~LED_SYSFS_DISABLE
;
324 EXPORT_SYMBOL_GPL(led_sysfs_enable
);