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>
20 #include <linux/rwsem.h>
21 #include <linux/slab.h>
24 DECLARE_RWSEM(leds_list_lock);
25 EXPORT_SYMBOL_GPL(leds_list_lock);
28 EXPORT_SYMBOL_GPL(leds_list);
30 static int __led_set_brightness(struct led_classdev *led_cdev,
31 enum led_brightness value)
33 if (!led_cdev->brightness_set)
36 led_cdev->brightness_set(led_cdev, value);
41 static int __led_set_brightness_blocking(struct led_classdev *led_cdev,
42 enum led_brightness value)
44 if (!led_cdev->brightness_set_blocking)
47 return led_cdev->brightness_set_blocking(led_cdev, value);
50 static void led_timer_function(struct timer_list *t)
52 struct led_classdev *led_cdev = from_timer(led_cdev, t, blink_timer);
53 unsigned long brightness;
56 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
57 led_set_brightness_nosleep(led_cdev, LED_OFF);
58 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
62 if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
63 &led_cdev->work_flags)) {
64 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
68 brightness = led_get_brightness(led_cdev);
70 /* Time to switch the LED on. */
71 if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
72 &led_cdev->work_flags))
73 brightness = led_cdev->new_blink_brightness;
75 brightness = led_cdev->blink_brightness;
76 delay = led_cdev->blink_delay_on;
78 /* Store the current brightness value to be able
79 * to restore it when the delay_off period is over.
81 led_cdev->blink_brightness = brightness;
83 delay = led_cdev->blink_delay_off;
86 led_set_brightness_nosleep(led_cdev, brightness);
88 /* Return in next iteration if led is in one-shot mode and we are in
89 * the final blink state so that the led is toggled each delay_on +
90 * delay_off milliseconds in worst case.
92 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
93 if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
95 set_bit(LED_BLINK_ONESHOT_STOP,
96 &led_cdev->work_flags);
99 set_bit(LED_BLINK_ONESHOT_STOP,
100 &led_cdev->work_flags);
104 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
107 static void set_brightness_delayed(struct work_struct *ws)
109 struct led_classdev *led_cdev =
110 container_of(ws, struct led_classdev, set_brightness_work);
113 if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
114 led_cdev->delayed_set_value = LED_OFF;
115 led_stop_software_blink(led_cdev);
118 ret = __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
119 if (ret == -ENOTSUPP)
120 ret = __led_set_brightness_blocking(led_cdev,
121 led_cdev->delayed_set_value);
123 /* LED HW might have been unplugged, therefore don't warn */
124 !(ret == -ENODEV && (led_cdev->flags & LED_UNREGISTERING) &&
125 (led_cdev->flags & LED_HW_PLUGGABLE)))
126 dev_err(led_cdev->dev,
127 "Setting an LED's brightness failed (%d)\n", ret);
130 static void led_set_software_blink(struct led_classdev *led_cdev,
131 unsigned long delay_on,
132 unsigned long delay_off)
134 int current_brightness;
136 current_brightness = led_get_brightness(led_cdev);
137 if (current_brightness)
138 led_cdev->blink_brightness = current_brightness;
139 if (!led_cdev->blink_brightness)
140 led_cdev->blink_brightness = led_cdev->max_brightness;
142 led_cdev->blink_delay_on = delay_on;
143 led_cdev->blink_delay_off = delay_off;
145 /* never on - just set to off */
147 led_set_brightness_nosleep(led_cdev, LED_OFF);
151 /* never off - just set to brightness */
153 led_set_brightness_nosleep(led_cdev,
154 led_cdev->blink_brightness);
158 set_bit(LED_BLINK_SW, &led_cdev->work_flags);
159 mod_timer(&led_cdev->blink_timer, jiffies + 1);
163 static void led_blink_setup(struct led_classdev *led_cdev,
164 unsigned long *delay_on,
165 unsigned long *delay_off)
168 * If "set brightness to 0" is pending in workqueue, we don't
169 * want that to be reordered after blink_set()
171 flush_work(&led_cdev->set_brightness_work);
172 if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
173 led_cdev->blink_set &&
174 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
177 /* blink with 1 Hz as default if nothing specified */
178 if (!*delay_on && !*delay_off)
179 *delay_on = *delay_off = 500;
181 led_set_software_blink(led_cdev, *delay_on, *delay_off);
184 void led_init_core(struct led_classdev *led_cdev)
186 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
188 timer_setup(&led_cdev->blink_timer, led_timer_function, 0);
190 EXPORT_SYMBOL_GPL(led_init_core);
192 void led_blink_set(struct led_classdev *led_cdev,
193 unsigned long *delay_on,
194 unsigned long *delay_off)
196 del_timer_sync(&led_cdev->blink_timer);
198 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
199 clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
200 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
202 led_blink_setup(led_cdev, delay_on, delay_off);
204 EXPORT_SYMBOL_GPL(led_blink_set);
206 void led_blink_set_oneshot(struct led_classdev *led_cdev,
207 unsigned long *delay_on,
208 unsigned long *delay_off,
211 if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
212 timer_pending(&led_cdev->blink_timer))
215 set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
216 clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
219 set_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
221 clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
223 led_blink_setup(led_cdev, delay_on, delay_off);
225 EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
227 void led_stop_software_blink(struct led_classdev *led_cdev)
229 del_timer_sync(&led_cdev->blink_timer);
230 led_cdev->blink_delay_on = 0;
231 led_cdev->blink_delay_off = 0;
232 clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
234 EXPORT_SYMBOL_GPL(led_stop_software_blink);
236 void led_set_brightness(struct led_classdev *led_cdev,
237 enum led_brightness brightness)
240 * If software blink is active, delay brightness setting
241 * until the next timer tick.
243 if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
245 * If we need to disable soft blinking delegate this to the
246 * work queue task to avoid problems in case we are called
247 * from hard irq context.
249 if (brightness == LED_OFF) {
250 set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags);
251 schedule_work(&led_cdev->set_brightness_work);
253 set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
254 &led_cdev->work_flags);
255 led_cdev->new_blink_brightness = brightness;
260 led_set_brightness_nosleep(led_cdev, brightness);
262 EXPORT_SYMBOL_GPL(led_set_brightness);
264 void led_set_brightness_nopm(struct led_classdev *led_cdev,
265 enum led_brightness value)
267 /* Use brightness_set op if available, it is guaranteed not to sleep */
268 if (!__led_set_brightness(led_cdev, value))
271 /* If brightness setting can sleep, delegate it to a work queue task */
272 led_cdev->delayed_set_value = value;
273 schedule_work(&led_cdev->set_brightness_work);
275 EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
277 void led_set_brightness_nosleep(struct led_classdev *led_cdev,
278 enum led_brightness value)
280 led_cdev->brightness = min(value, led_cdev->max_brightness);
282 if (led_cdev->flags & LED_SUSPENDED)
285 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
287 EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
289 int led_set_brightness_sync(struct led_classdev *led_cdev,
290 enum led_brightness value)
292 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
295 led_cdev->brightness = min(value, led_cdev->max_brightness);
297 if (led_cdev->flags & LED_SUSPENDED)
300 return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
302 EXPORT_SYMBOL_GPL(led_set_brightness_sync);
304 int led_update_brightness(struct led_classdev *led_cdev)
308 if (led_cdev->brightness_get) {
309 ret = led_cdev->brightness_get(led_cdev);
311 led_cdev->brightness = ret;
318 EXPORT_SYMBOL_GPL(led_update_brightness);
320 u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size)
322 struct device_node *np = dev_of_node(led_cdev->dev);
329 count = of_property_count_u32_elems(np, "led-pattern");
333 pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL);
337 if (of_property_read_u32_array(np, "led-pattern", pattern, count)) {
346 EXPORT_SYMBOL_GPL(led_get_default_pattern);
348 /* Caller must ensure led_cdev->led_access held */
349 void led_sysfs_disable(struct led_classdev *led_cdev)
351 lockdep_assert_held(&led_cdev->led_access);
353 led_cdev->flags |= LED_SYSFS_DISABLE;
355 EXPORT_SYMBOL_GPL(led_sysfs_disable);
357 /* Caller must ensure led_cdev->led_access held */
358 void led_sysfs_enable(struct led_classdev *led_cdev)
360 lockdep_assert_held(&led_cdev->led_access);
362 led_cdev->flags &= ~LED_SYSFS_DISABLE;
364 EXPORT_SYMBOL_GPL(led_sysfs_enable);