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);