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1/*
2 * LED Class Core
3 *
4 * Copyright 2005-2006 Openedhand Ltd.
5 *
6 * Author: Richard Purdie <rpurdie@openedhand.com>
7 *
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.
11 *
12 */
13
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>
20#include "leds.h"
21
22DECLARE_RWSEM(leds_list_lock);
23EXPORT_SYMBOL_GPL(leds_list_lock);
24
25LIST_HEAD(leds_list);
26EXPORT_SYMBOL_GPL(leds_list);
27
28static int __led_set_brightness(struct led_classdev *led_cdev,
29 enum led_brightness value)
30{
31 if (!led_cdev->brightness_set)
32 return -ENOTSUPP;
33
34 led_cdev->brightness_set(led_cdev, value);
35
36 return 0;
37}
38
39static int __led_set_brightness_blocking(struct led_classdev *led_cdev,
40 enum led_brightness value)
41{
42 if (!led_cdev->brightness_set_blocking)
43 return -ENOTSUPP;
44
45 return led_cdev->brightness_set_blocking(led_cdev, value);
46}
47
48static void led_timer_function(unsigned long data)
49{
50 struct led_classdev *led_cdev = (void *)data;
51 unsigned long brightness;
52 unsigned long delay;
53
54 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
55 led_set_brightness_nosleep(led_cdev, LED_OFF);
56 return;
57 }
58
59 if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
60 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
61 return;
62 }
63
64 brightness = led_get_brightness(led_cdev);
65 if (!brightness) {
66 /* Time to switch the LED on. */
67 brightness = led_cdev->blink_brightness;
68 delay = led_cdev->blink_delay_on;
69 } else {
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.
74 */
75 if (!(led_cdev->flags & LED_BLINK_BRIGHTNESS_CHANGE))
76 led_cdev->blink_brightness = brightness;
77 else
78 led_cdev->flags &= ~LED_BLINK_BRIGHTNESS_CHANGE;
79 brightness = LED_OFF;
80 delay = led_cdev->blink_delay_off;
81 }
82
83 led_set_brightness_nosleep(led_cdev, brightness);
84
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.
88 */
89 if (led_cdev->flags & LED_BLINK_ONESHOT) {
90 if (led_cdev->flags & LED_BLINK_INVERT) {
91 if (brightness)
92 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
93 } else {
94 if (!brightness)
95 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
96 }
97 }
98
99 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
100}
101
102static void set_brightness_delayed(struct work_struct *ws)
103{
104 struct led_classdev *led_cdev =
105 container_of(ws, struct led_classdev, set_brightness_work);
106 int ret = 0;
107
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;
112 }
113
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);
118 if (ret < 0 &&
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);
124}
125
126static void led_set_software_blink(struct led_classdev *led_cdev,
127 unsigned long delay_on,
128 unsigned long delay_off)
129{
130 int current_brightness;
131
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;
137
138 led_cdev->blink_delay_on = delay_on;
139 led_cdev->blink_delay_off = delay_off;
140
141 /* never on - just set to off */
142 if (!delay_on) {
143 led_set_brightness_nosleep(led_cdev, LED_OFF);
144 return;
145 }
146
147 /* never off - just set to brightness */
148 if (!delay_off) {
149 led_set_brightness_nosleep(led_cdev,
150 led_cdev->blink_brightness);
151 return;
152 }
153
154 mod_timer(&led_cdev->blink_timer, jiffies + 1);
155}
156
157
158static void led_blink_setup(struct led_classdev *led_cdev,
159 unsigned long *delay_on,
160 unsigned long *delay_off)
161{
162 if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
163 led_cdev->blink_set &&
164 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
165 return;
166
167 /* blink with 1 Hz as default if nothing specified */
168 if (!*delay_on && !*delay_off)
169 *delay_on = *delay_off = 500;
170
171 led_set_software_blink(led_cdev, *delay_on, *delay_off);
172}
173
174void led_init_core(struct led_classdev *led_cdev)
175{
176 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
177
178 setup_timer(&led_cdev->blink_timer, led_timer_function,
179 (unsigned long)led_cdev);
180}
181EXPORT_SYMBOL_GPL(led_init_core);
182
183void led_blink_set(struct led_classdev *led_cdev,
184 unsigned long *delay_on,
185 unsigned long *delay_off)
186{
187 del_timer_sync(&led_cdev->blink_timer);
188
189 led_cdev->flags &= ~LED_BLINK_ONESHOT;
190 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
191
192 led_blink_setup(led_cdev, delay_on, delay_off);
193}
194EXPORT_SYMBOL_GPL(led_blink_set);
195
196void led_blink_set_oneshot(struct led_classdev *led_cdev,
197 unsigned long *delay_on,
198 unsigned long *delay_off,
199 int invert)
200{
201 if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
202 timer_pending(&led_cdev->blink_timer))
203 return;
204
205 led_cdev->flags |= LED_BLINK_ONESHOT;
206 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
207
208 if (invert)
209 led_cdev->flags |= LED_BLINK_INVERT;
210 else
211 led_cdev->flags &= ~LED_BLINK_INVERT;
212
213 led_blink_setup(led_cdev, delay_on, delay_off);
214}
215EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
216
217void led_stop_software_blink(struct led_classdev *led_cdev)
218{
219 del_timer_sync(&led_cdev->blink_timer);
220 led_cdev->blink_delay_on = 0;
221 led_cdev->blink_delay_off = 0;
222}
223EXPORT_SYMBOL_GPL(led_stop_software_blink);
224
225void led_set_brightness(struct led_classdev *led_cdev,
226 enum led_brightness brightness)
227{
228 /*
229 * In case blinking is on delay brightness setting
230 * until the next timer tick.
231 */
232 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) {
233 /*
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.
237 */
238 if (brightness == LED_OFF) {
239 led_cdev->flags |= LED_BLINK_DISABLE;
240 schedule_work(&led_cdev->set_brightness_work);
241 } else {
242 led_cdev->flags |= LED_BLINK_BRIGHTNESS_CHANGE;
243 led_cdev->blink_brightness = brightness;
244 }
245 return;
246 }
247
248 led_set_brightness_nosleep(led_cdev, brightness);
249}
250EXPORT_SYMBOL_GPL(led_set_brightness);
251
252void led_set_brightness_nopm(struct led_classdev *led_cdev,
253 enum led_brightness value)
254{
255 /* Use brightness_set op if available, it is guaranteed not to sleep */
256 if (!__led_set_brightness(led_cdev, value))
257 return;
258
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);
262}
263EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
264
265void led_set_brightness_nosleep(struct led_classdev *led_cdev,
266 enum led_brightness value)
267{
268 led_cdev->brightness = min(value, led_cdev->max_brightness);
269
270 if (led_cdev->flags & LED_SUSPENDED)
271 return;
272
273 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
274}
275EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
276
277int led_set_brightness_sync(struct led_classdev *led_cdev,
278 enum led_brightness value)
279{
280 if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
281 return -EBUSY;
282
283 led_cdev->brightness = min(value, led_cdev->max_brightness);
284
285 if (led_cdev->flags & LED_SUSPENDED)
286 return 0;
287
288 return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
289}
290EXPORT_SYMBOL_GPL(led_set_brightness_sync);
291
292int led_update_brightness(struct led_classdev *led_cdev)
293{
294 int ret = 0;
295
296 if (led_cdev->brightness_get) {
297 ret = led_cdev->brightness_get(led_cdev);
298 if (ret >= 0) {
299 led_cdev->brightness = ret;
300 return 0;
301 }
302 }
303
304 return ret;
305}
306EXPORT_SYMBOL_GPL(led_update_brightness);
307
308/* Caller must ensure led_cdev->led_access held */
309void led_sysfs_disable(struct led_classdev *led_cdev)
310{
311 lockdep_assert_held(&led_cdev->led_access);
312
313 led_cdev->flags |= LED_SYSFS_DISABLE;
314}
315EXPORT_SYMBOL_GPL(led_sysfs_disable);
316
317/* Caller must ensure led_cdev->led_access held */
318void led_sysfs_enable(struct led_classdev *led_cdev)
319{
320 lockdep_assert_held(&led_cdev->led_access);
321
322 led_cdev->flags &= ~LED_SYSFS_DISABLE;
323}
324EXPORT_SYMBOL_GPL(led_sysfs_enable);
1/*
2 * LED Class Core
3 *
4 * Copyright 2005-2006 Openedhand Ltd.
5 *
6 * Author: Richard Purdie <rpurdie@openedhand.com>
7 *
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.
11 *
12 */
13
14#include <linux/kernel.h>
15#include <linux/list.h>
16#include <linux/module.h>
17#include <linux/rwsem.h>
18#include <linux/leds.h>
19#include "leds.h"
20
21DECLARE_RWSEM(leds_list_lock);
22EXPORT_SYMBOL_GPL(leds_list_lock);
23
24LIST_HEAD(leds_list);
25EXPORT_SYMBOL_GPL(leds_list);