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(struct timer_list
*t
)
50 struct led_classdev
*led_cdev
= from_timer(led_cdev
, t
, blink_timer
);
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
);
56 clear_bit(LED_BLINK_SW
, &led_cdev
->work_flags
);
60 if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP
,
61 &led_cdev
->work_flags
)) {
62 clear_bit(LED_BLINK_SW
, &led_cdev
->work_flags
);
66 brightness
= led_get_brightness(led_cdev
);
68 /* Time to switch the LED on. */
69 if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE
,
70 &led_cdev
->work_flags
))
71 brightness
= led_cdev
->new_blink_brightness
;
73 brightness
= led_cdev
->blink_brightness
;
74 delay
= led_cdev
->blink_delay_on
;
76 /* Store the current brightness value to be able
77 * to restore it when the delay_off period is over.
79 led_cdev
->blink_brightness
= brightness
;
81 delay
= led_cdev
->blink_delay_off
;
84 led_set_brightness_nosleep(led_cdev
, brightness
);
86 /* Return in next iteration if led is in one-shot mode and we are in
87 * the final blink state so that the led is toggled each delay_on +
88 * delay_off milliseconds in worst case.
90 if (test_bit(LED_BLINK_ONESHOT
, &led_cdev
->work_flags
)) {
91 if (test_bit(LED_BLINK_INVERT
, &led_cdev
->work_flags
)) {
93 set_bit(LED_BLINK_ONESHOT_STOP
,
94 &led_cdev
->work_flags
);
97 set_bit(LED_BLINK_ONESHOT_STOP
,
98 &led_cdev
->work_flags
);
102 mod_timer(&led_cdev
->blink_timer
, jiffies
+ msecs_to_jiffies(delay
));
105 static void set_brightness_delayed(struct work_struct
*ws
)
107 struct led_classdev
*led_cdev
=
108 container_of(ws
, struct led_classdev
, set_brightness_work
);
111 if (test_and_clear_bit(LED_BLINK_DISABLE
, &led_cdev
->work_flags
)) {
112 led_cdev
->delayed_set_value
= LED_OFF
;
113 led_stop_software_blink(led_cdev
);
116 ret
= __led_set_brightness(led_cdev
, led_cdev
->delayed_set_value
);
117 if (ret
== -ENOTSUPP
)
118 ret
= __led_set_brightness_blocking(led_cdev
,
119 led_cdev
->delayed_set_value
);
121 /* LED HW might have been unplugged, therefore don't warn */
122 !(ret
== -ENODEV
&& (led_cdev
->flags
& LED_UNREGISTERING
) &&
123 (led_cdev
->flags
& LED_HW_PLUGGABLE
)))
124 dev_err(led_cdev
->dev
,
125 "Setting an LED's brightness failed (%d)\n", ret
);
128 static void led_set_software_blink(struct led_classdev
*led_cdev
,
129 unsigned long delay_on
,
130 unsigned long delay_off
)
132 int current_brightness
;
134 current_brightness
= led_get_brightness(led_cdev
);
135 if (current_brightness
)
136 led_cdev
->blink_brightness
= current_brightness
;
137 if (!led_cdev
->blink_brightness
)
138 led_cdev
->blink_brightness
= led_cdev
->max_brightness
;
140 led_cdev
->blink_delay_on
= delay_on
;
141 led_cdev
->blink_delay_off
= delay_off
;
143 /* never on - just set to off */
145 led_set_brightness_nosleep(led_cdev
, LED_OFF
);
149 /* never off - just set to brightness */
151 led_set_brightness_nosleep(led_cdev
,
152 led_cdev
->blink_brightness
);
156 set_bit(LED_BLINK_SW
, &led_cdev
->work_flags
);
157 mod_timer(&led_cdev
->blink_timer
, jiffies
+ 1);
161 static void led_blink_setup(struct led_classdev
*led_cdev
,
162 unsigned long *delay_on
,
163 unsigned long *delay_off
)
165 if (!test_bit(LED_BLINK_ONESHOT
, &led_cdev
->work_flags
) &&
166 led_cdev
->blink_set
&&
167 !led_cdev
->blink_set(led_cdev
, delay_on
, delay_off
))
170 /* blink with 1 Hz as default if nothing specified */
171 if (!*delay_on
&& !*delay_off
)
172 *delay_on
= *delay_off
= 500;
174 led_set_software_blink(led_cdev
, *delay_on
, *delay_off
);
177 void led_init_core(struct led_classdev
*led_cdev
)
179 INIT_WORK(&led_cdev
->set_brightness_work
, set_brightness_delayed
);
181 timer_setup(&led_cdev
->blink_timer
, led_timer_function
, 0);
183 EXPORT_SYMBOL_GPL(led_init_core
);
185 void led_blink_set(struct led_classdev
*led_cdev
,
186 unsigned long *delay_on
,
187 unsigned long *delay_off
)
189 del_timer_sync(&led_cdev
->blink_timer
);
191 clear_bit(LED_BLINK_ONESHOT
, &led_cdev
->work_flags
);
192 clear_bit(LED_BLINK_ONESHOT_STOP
, &led_cdev
->work_flags
);
194 led_blink_setup(led_cdev
, delay_on
, delay_off
);
196 EXPORT_SYMBOL_GPL(led_blink_set
);
198 void led_blink_set_oneshot(struct led_classdev
*led_cdev
,
199 unsigned long *delay_on
,
200 unsigned long *delay_off
,
203 if (test_bit(LED_BLINK_ONESHOT
, &led_cdev
->work_flags
) &&
204 timer_pending(&led_cdev
->blink_timer
))
207 set_bit(LED_BLINK_ONESHOT
, &led_cdev
->work_flags
);
208 clear_bit(LED_BLINK_ONESHOT_STOP
, &led_cdev
->work_flags
);
211 set_bit(LED_BLINK_INVERT
, &led_cdev
->work_flags
);
213 clear_bit(LED_BLINK_INVERT
, &led_cdev
->work_flags
);
215 led_blink_setup(led_cdev
, delay_on
, delay_off
);
217 EXPORT_SYMBOL_GPL(led_blink_set_oneshot
);
219 void led_stop_software_blink(struct led_classdev
*led_cdev
)
221 del_timer_sync(&led_cdev
->blink_timer
);
222 led_cdev
->blink_delay_on
= 0;
223 led_cdev
->blink_delay_off
= 0;
224 clear_bit(LED_BLINK_SW
, &led_cdev
->work_flags
);
226 EXPORT_SYMBOL_GPL(led_stop_software_blink
);
228 void led_set_brightness(struct led_classdev
*led_cdev
,
229 enum led_brightness brightness
)
232 * If software blink is active, delay brightness setting
233 * until the next timer tick.
235 if (test_bit(LED_BLINK_SW
, &led_cdev
->work_flags
)) {
237 * If we need to disable soft blinking delegate this to the
238 * work queue task to avoid problems in case we are called
239 * from hard irq context.
241 if (brightness
== LED_OFF
) {
242 set_bit(LED_BLINK_DISABLE
, &led_cdev
->work_flags
);
243 schedule_work(&led_cdev
->set_brightness_work
);
245 set_bit(LED_BLINK_BRIGHTNESS_CHANGE
,
246 &led_cdev
->work_flags
);
247 led_cdev
->new_blink_brightness
= brightness
;
252 led_set_brightness_nosleep(led_cdev
, brightness
);
254 EXPORT_SYMBOL_GPL(led_set_brightness
);
256 void led_set_brightness_nopm(struct led_classdev
*led_cdev
,
257 enum led_brightness value
)
259 /* Use brightness_set op if available, it is guaranteed not to sleep */
260 if (!__led_set_brightness(led_cdev
, value
))
263 /* If brightness setting can sleep, delegate it to a work queue task */
264 led_cdev
->delayed_set_value
= value
;
265 schedule_work(&led_cdev
->set_brightness_work
);
267 EXPORT_SYMBOL_GPL(led_set_brightness_nopm
);
269 void led_set_brightness_nosleep(struct led_classdev
*led_cdev
,
270 enum led_brightness value
)
272 led_cdev
->brightness
= min(value
, led_cdev
->max_brightness
);
274 if (led_cdev
->flags
& LED_SUSPENDED
)
277 led_set_brightness_nopm(led_cdev
, led_cdev
->brightness
);
279 EXPORT_SYMBOL_GPL(led_set_brightness_nosleep
);
281 int led_set_brightness_sync(struct led_classdev
*led_cdev
,
282 enum led_brightness value
)
284 if (led_cdev
->blink_delay_on
|| led_cdev
->blink_delay_off
)
287 led_cdev
->brightness
= min(value
, led_cdev
->max_brightness
);
289 if (led_cdev
->flags
& LED_SUSPENDED
)
292 return __led_set_brightness_blocking(led_cdev
, led_cdev
->brightness
);
294 EXPORT_SYMBOL_GPL(led_set_brightness_sync
);
296 int led_update_brightness(struct led_classdev
*led_cdev
)
300 if (led_cdev
->brightness_get
) {
301 ret
= led_cdev
->brightness_get(led_cdev
);
303 led_cdev
->brightness
= ret
;
310 EXPORT_SYMBOL_GPL(led_update_brightness
);
312 /* Caller must ensure led_cdev->led_access held */
313 void led_sysfs_disable(struct led_classdev
*led_cdev
)
315 lockdep_assert_held(&led_cdev
->led_access
);
317 led_cdev
->flags
|= LED_SYSFS_DISABLE
;
319 EXPORT_SYMBOL_GPL(led_sysfs_disable
);
321 /* Caller must ensure led_cdev->led_access held */
322 void led_sysfs_enable(struct led_classdev
*led_cdev
)
324 lockdep_assert_held(&led_cdev
->led_access
);
326 led_cdev
->flags
&= ~LED_SYSFS_DISABLE
;
328 EXPORT_SYMBOL_GPL(led_sysfs_enable
);