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1/*
2 * LED Class Core
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/list.h>
16#include <linux/spinlock.h>
17#include <linux/device.h>
18#include <linux/sysdev.h>
19#include <linux/timer.h>
20#include <linux/err.h>
21#include <linux/ctype.h>
22#include <linux/leds.h>
23#include "leds.h"
24
25static struct class *leds_class;
26
27static void led_update_brightness(struct led_classdev *led_cdev)
28{
29 if (led_cdev->brightness_get)
30 led_cdev->brightness = led_cdev->brightness_get(led_cdev);
31}
32
33static ssize_t led_brightness_show(struct device *dev,
34 struct device_attribute *attr, char *buf)
35{
36 struct led_classdev *led_cdev = dev_get_drvdata(dev);
37
38 /* no lock needed for this */
39 led_update_brightness(led_cdev);
40
41 return sprintf(buf, "%u\n", led_cdev->brightness);
42}
43
44static ssize_t led_brightness_store(struct device *dev,
45 struct device_attribute *attr, const char *buf, size_t size)
46{
47 struct led_classdev *led_cdev = dev_get_drvdata(dev);
48 ssize_t ret = -EINVAL;
49 char *after;
50 unsigned long state = simple_strtoul(buf, &after, 10);
51 size_t count = after - buf;
52
53 if (isspace(*after))
54 count++;
55
56 if (count == size) {
57 ret = count;
58
59 if (state == LED_OFF)
60 led_trigger_remove(led_cdev);
61 led_set_brightness(led_cdev, state);
62 }
63
64 return ret;
65}
66
67static ssize_t led_max_brightness_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
69{
70 struct led_classdev *led_cdev = dev_get_drvdata(dev);
71
72 return sprintf(buf, "%u\n", led_cdev->max_brightness);
73}
74
75static struct device_attribute led_class_attrs[] = {
76 __ATTR(brightness, 0644, led_brightness_show, led_brightness_store),
77 __ATTR(max_brightness, 0444, led_max_brightness_show, NULL),
78#ifdef CONFIG_LEDS_TRIGGERS
79 __ATTR(trigger, 0644, led_trigger_show, led_trigger_store),
80#endif
81 __ATTR_NULL,
82};
83
84static void led_timer_function(unsigned long data)
85{
86 struct led_classdev *led_cdev = (void *)data;
87 unsigned long brightness;
88 unsigned long delay;
89
90 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
91 led_set_brightness(led_cdev, LED_OFF);
92 return;
93 }
94
95 brightness = led_get_brightness(led_cdev);
96 if (!brightness) {
97 /* Time to switch the LED on. */
98 brightness = led_cdev->blink_brightness;
99 delay = led_cdev->blink_delay_on;
100 } else {
101 /* Store the current brightness value to be able
102 * to restore it when the delay_off period is over.
103 */
104 led_cdev->blink_brightness = brightness;
105 brightness = LED_OFF;
106 delay = led_cdev->blink_delay_off;
107 }
108
109 led_set_brightness(led_cdev, brightness);
110
111 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
112}
113
114static void led_stop_software_blink(struct led_classdev *led_cdev)
115{
116 /* deactivate previous settings */
117 del_timer_sync(&led_cdev->blink_timer);
118 led_cdev->blink_delay_on = 0;
119 led_cdev->blink_delay_off = 0;
120}
121
122static void led_set_software_blink(struct led_classdev *led_cdev,
123 unsigned long delay_on,
124 unsigned long delay_off)
125{
126 int current_brightness;
127
128 current_brightness = led_get_brightness(led_cdev);
129 if (current_brightness)
130 led_cdev->blink_brightness = current_brightness;
131 if (!led_cdev->blink_brightness)
132 led_cdev->blink_brightness = led_cdev->max_brightness;
133
134 if (led_get_trigger_data(led_cdev) &&
135 delay_on == led_cdev->blink_delay_on &&
136 delay_off == led_cdev->blink_delay_off)
137 return;
138
139 led_stop_software_blink(led_cdev);
140
141 led_cdev->blink_delay_on = delay_on;
142 led_cdev->blink_delay_off = delay_off;
143
144 /* never on - don't blink */
145 if (!delay_on)
146 return;
147
148 /* never off - just set to brightness */
149 if (!delay_off) {
150 led_set_brightness(led_cdev, led_cdev->blink_brightness);
151 return;
152 }
153
154 mod_timer(&led_cdev->blink_timer, jiffies + 1);
155}
156
157
158/**
159 * led_classdev_suspend - suspend an led_classdev.
160 * @led_cdev: the led_classdev to suspend.
161 */
162void led_classdev_suspend(struct led_classdev *led_cdev)
163{
164 led_cdev->flags |= LED_SUSPENDED;
165 led_cdev->brightness_set(led_cdev, 0);
166}
167EXPORT_SYMBOL_GPL(led_classdev_suspend);
168
169/**
170 * led_classdev_resume - resume an led_classdev.
171 * @led_cdev: the led_classdev to resume.
172 */
173void led_classdev_resume(struct led_classdev *led_cdev)
174{
175 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
176 led_cdev->flags &= ~LED_SUSPENDED;
177}
178EXPORT_SYMBOL_GPL(led_classdev_resume);
179
180static int led_suspend(struct device *dev, pm_message_t state)
181{
182 struct led_classdev *led_cdev = dev_get_drvdata(dev);
183
184 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
185 led_classdev_suspend(led_cdev);
186
187 return 0;
188}
189
190static int led_resume(struct device *dev)
191{
192 struct led_classdev *led_cdev = dev_get_drvdata(dev);
193
194 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
195 led_classdev_resume(led_cdev);
196
197 return 0;
198}
199
200/**
201 * led_classdev_register - register a new object of led_classdev class.
202 * @parent: The device to register.
203 * @led_cdev: the led_classdev structure for this device.
204 */
205int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
206{
207 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
208 "%s", led_cdev->name);
209 if (IS_ERR(led_cdev->dev))
210 return PTR_ERR(led_cdev->dev);
211
212#ifdef CONFIG_LEDS_TRIGGERS
213 init_rwsem(&led_cdev->trigger_lock);
214#endif
215 /* add to the list of leds */
216 down_write(&leds_list_lock);
217 list_add_tail(&led_cdev->node, &leds_list);
218 up_write(&leds_list_lock);
219
220 if (!led_cdev->max_brightness)
221 led_cdev->max_brightness = LED_FULL;
222
223 led_update_brightness(led_cdev);
224
225 init_timer(&led_cdev->blink_timer);
226 led_cdev->blink_timer.function = led_timer_function;
227 led_cdev->blink_timer.data = (unsigned long)led_cdev;
228
229#ifdef CONFIG_LEDS_TRIGGERS
230 led_trigger_set_default(led_cdev);
231#endif
232
233 printk(KERN_DEBUG "Registered led device: %s\n",
234 led_cdev->name);
235
236 return 0;
237}
238EXPORT_SYMBOL_GPL(led_classdev_register);
239
240/**
241 * led_classdev_unregister - unregisters a object of led_properties class.
242 * @led_cdev: the led device to unregister
243 *
244 * Unregisters a previously registered via led_classdev_register object.
245 */
246void led_classdev_unregister(struct led_classdev *led_cdev)
247{
248#ifdef CONFIG_LEDS_TRIGGERS
249 down_write(&led_cdev->trigger_lock);
250 if (led_cdev->trigger)
251 led_trigger_set(led_cdev, NULL);
252 up_write(&led_cdev->trigger_lock);
253#endif
254
255 /* Stop blinking */
256 led_brightness_set(led_cdev, LED_OFF);
257
258 device_unregister(led_cdev->dev);
259
260 down_write(&leds_list_lock);
261 list_del(&led_cdev->node);
262 up_write(&leds_list_lock);
263}
264EXPORT_SYMBOL_GPL(led_classdev_unregister);
265
266void led_blink_set(struct led_classdev *led_cdev,
267 unsigned long *delay_on,
268 unsigned long *delay_off)
269{
270 if (led_cdev->blink_set &&
271 !led_cdev->blink_set(led_cdev, delay_on, delay_off))
272 return;
273
274 /* blink with 1 Hz as default if nothing specified */
275 if (!*delay_on && !*delay_off)
276 *delay_on = *delay_off = 500;
277
278 led_set_software_blink(led_cdev, *delay_on, *delay_off);
279}
280EXPORT_SYMBOL(led_blink_set);
281
282void led_brightness_set(struct led_classdev *led_cdev,
283 enum led_brightness brightness)
284{
285 led_stop_software_blink(led_cdev);
286 led_cdev->brightness_set(led_cdev, brightness);
287}
288EXPORT_SYMBOL(led_brightness_set);
289
290static int __init leds_init(void)
291{
292 leds_class = class_create(THIS_MODULE, "leds");
293 if (IS_ERR(leds_class))
294 return PTR_ERR(leds_class);
295 leds_class->suspend = led_suspend;
296 leds_class->resume = led_resume;
297 leds_class->dev_attrs = led_class_attrs;
298 return 0;
299}
300
301static void __exit leds_exit(void)
302{
303 class_destroy(leds_class);
304}
305
306subsys_initcall(leds_init);
307module_exit(leds_exit);
308
309MODULE_AUTHOR("John Lenz, Richard Purdie");
310MODULE_LICENSE("GPL");
311MODULE_DESCRIPTION("LED Class Interface");
1/*
2 * LED Class Core
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/list.h>
16#include <linux/spinlock.h>
17#include <linux/device.h>
18#include <linux/timer.h>
19#include <linux/err.h>
20#include <linux/ctype.h>
21#include <linux/leds.h>
22#include "leds.h"
23
24static struct class *leds_class;
25
26static void led_update_brightness(struct led_classdev *led_cdev)
27{
28 if (led_cdev->brightness_get)
29 led_cdev->brightness = led_cdev->brightness_get(led_cdev);
30}
31
32static ssize_t brightness_show(struct device *dev,
33 struct device_attribute *attr, char *buf)
34{
35 struct led_classdev *led_cdev = dev_get_drvdata(dev);
36
37 /* no lock needed for this */
38 led_update_brightness(led_cdev);
39
40 return sprintf(buf, "%u\n", led_cdev->brightness);
41}
42
43static ssize_t brightness_store(struct device *dev,
44 struct device_attribute *attr, const char *buf, size_t size)
45{
46 struct led_classdev *led_cdev = dev_get_drvdata(dev);
47 unsigned long state;
48 ssize_t ret = -EINVAL;
49
50 ret = kstrtoul(buf, 10, &state);
51 if (ret)
52 return ret;
53
54 if (state == LED_OFF)
55 led_trigger_remove(led_cdev);
56 __led_set_brightness(led_cdev, state);
57
58 return size;
59}
60static DEVICE_ATTR_RW(brightness);
61
62static ssize_t led_max_brightness_show(struct device *dev,
63 struct device_attribute *attr, char *buf)
64{
65 struct led_classdev *led_cdev = dev_get_drvdata(dev);
66
67 return sprintf(buf, "%u\n", led_cdev->max_brightness);
68}
69static DEVICE_ATTR(max_brightness, 0444, led_max_brightness_show, NULL);
70
71#ifdef CONFIG_LEDS_TRIGGERS
72static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
73static struct attribute *led_trigger_attrs[] = {
74 &dev_attr_trigger.attr,
75 NULL,
76};
77static const struct attribute_group led_trigger_group = {
78 .attrs = led_trigger_attrs,
79};
80#endif
81
82static struct attribute *led_class_attrs[] = {
83 &dev_attr_brightness.attr,
84 &dev_attr_max_brightness.attr,
85 NULL,
86};
87
88static const struct attribute_group led_group = {
89 .attrs = led_class_attrs,
90};
91
92static const struct attribute_group *led_groups[] = {
93 &led_group,
94#ifdef CONFIG_LEDS_TRIGGERS
95 &led_trigger_group,
96#endif
97 NULL,
98};
99
100static void led_timer_function(unsigned long data)
101{
102 struct led_classdev *led_cdev = (void *)data;
103 unsigned long brightness;
104 unsigned long delay;
105
106 if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
107 __led_set_brightness(led_cdev, LED_OFF);
108 return;
109 }
110
111 if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) {
112 led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
113 return;
114 }
115
116 brightness = led_get_brightness(led_cdev);
117 if (!brightness) {
118 /* Time to switch the LED on. */
119 brightness = led_cdev->blink_brightness;
120 delay = led_cdev->blink_delay_on;
121 } else {
122 /* Store the current brightness value to be able
123 * to restore it when the delay_off period is over.
124 */
125 led_cdev->blink_brightness = brightness;
126 brightness = LED_OFF;
127 delay = led_cdev->blink_delay_off;
128 }
129
130 __led_set_brightness(led_cdev, brightness);
131
132 /* Return in next iteration if led is in one-shot mode and we are in
133 * the final blink state so that the led is toggled each delay_on +
134 * delay_off milliseconds in worst case.
135 */
136 if (led_cdev->flags & LED_BLINK_ONESHOT) {
137 if (led_cdev->flags & LED_BLINK_INVERT) {
138 if (brightness)
139 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
140 } else {
141 if (!brightness)
142 led_cdev->flags |= LED_BLINK_ONESHOT_STOP;
143 }
144 }
145
146 mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
147}
148
149static void set_brightness_delayed(struct work_struct *ws)
150{
151 struct led_classdev *led_cdev =
152 container_of(ws, struct led_classdev, set_brightness_work);
153
154 led_stop_software_blink(led_cdev);
155
156 __led_set_brightness(led_cdev, led_cdev->delayed_set_value);
157}
158
159/**
160 * led_classdev_suspend - suspend an led_classdev.
161 * @led_cdev: the led_classdev to suspend.
162 */
163void led_classdev_suspend(struct led_classdev *led_cdev)
164{
165 led_cdev->flags |= LED_SUSPENDED;
166 led_cdev->brightness_set(led_cdev, 0);
167}
168EXPORT_SYMBOL_GPL(led_classdev_suspend);
169
170/**
171 * led_classdev_resume - resume an led_classdev.
172 * @led_cdev: the led_classdev to resume.
173 */
174void led_classdev_resume(struct led_classdev *led_cdev)
175{
176 led_cdev->brightness_set(led_cdev, led_cdev->brightness);
177 led_cdev->flags &= ~LED_SUSPENDED;
178}
179EXPORT_SYMBOL_GPL(led_classdev_resume);
180
181static int led_suspend(struct device *dev)
182{
183 struct led_classdev *led_cdev = dev_get_drvdata(dev);
184
185 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
186 led_classdev_suspend(led_cdev);
187
188 return 0;
189}
190
191static int led_resume(struct device *dev)
192{
193 struct led_classdev *led_cdev = dev_get_drvdata(dev);
194
195 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
196 led_classdev_resume(led_cdev);
197
198 return 0;
199}
200
201static const struct dev_pm_ops leds_class_dev_pm_ops = {
202 .suspend = led_suspend,
203 .resume = led_resume,
204};
205
206/**
207 * led_classdev_register - register a new object of led_classdev class.
208 * @parent: The device to register.
209 * @led_cdev: the led_classdev structure for this device.
210 */
211int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
212{
213 led_cdev->dev = device_create(leds_class, parent, 0, led_cdev,
214 "%s", led_cdev->name);
215 if (IS_ERR(led_cdev->dev))
216 return PTR_ERR(led_cdev->dev);
217
218#ifdef CONFIG_LEDS_TRIGGERS
219 init_rwsem(&led_cdev->trigger_lock);
220#endif
221 /* add to the list of leds */
222 down_write(&leds_list_lock);
223 list_add_tail(&led_cdev->node, &leds_list);
224 up_write(&leds_list_lock);
225
226 if (!led_cdev->max_brightness)
227 led_cdev->max_brightness = LED_FULL;
228
229 led_update_brightness(led_cdev);
230
231 INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
232
233 init_timer(&led_cdev->blink_timer);
234 led_cdev->blink_timer.function = led_timer_function;
235 led_cdev->blink_timer.data = (unsigned long)led_cdev;
236
237#ifdef CONFIG_LEDS_TRIGGERS
238 led_trigger_set_default(led_cdev);
239#endif
240
241 dev_dbg(parent, "Registered led device: %s\n",
242 led_cdev->name);
243
244 return 0;
245}
246EXPORT_SYMBOL_GPL(led_classdev_register);
247
248/**
249 * led_classdev_unregister - unregisters a object of led_properties class.
250 * @led_cdev: the led device to unregister
251 *
252 * Unregisters a previously registered via led_classdev_register object.
253 */
254void led_classdev_unregister(struct led_classdev *led_cdev)
255{
256#ifdef CONFIG_LEDS_TRIGGERS
257 down_write(&led_cdev->trigger_lock);
258 if (led_cdev->trigger)
259 led_trigger_set(led_cdev, NULL);
260 up_write(&led_cdev->trigger_lock);
261#endif
262
263 cancel_work_sync(&led_cdev->set_brightness_work);
264
265 /* Stop blinking */
266 led_stop_software_blink(led_cdev);
267 led_set_brightness(led_cdev, LED_OFF);
268
269 device_unregister(led_cdev->dev);
270
271 down_write(&leds_list_lock);
272 list_del(&led_cdev->node);
273 up_write(&leds_list_lock);
274}
275EXPORT_SYMBOL_GPL(led_classdev_unregister);
276
277static int __init leds_init(void)
278{
279 leds_class = class_create(THIS_MODULE, "leds");
280 if (IS_ERR(leds_class))
281 return PTR_ERR(leds_class);
282 leds_class->pm = &leds_class_dev_pm_ops;
283 leds_class->dev_groups = led_groups;
284 return 0;
285}
286
287static void __exit leds_exit(void)
288{
289 class_destroy(leds_class);
290}
291
292subsys_initcall(leds_init);
293module_exit(leds_exit);
294
295MODULE_AUTHOR("John Lenz, Richard Purdie");
296MODULE_LICENSE("GPL");
297MODULE_DESCRIPTION("LED Class Interface");