leds: class: Add new optional brightness_hw_changed attribute
[linux-2.6-block.git] / drivers / leds / led-class.c
CommitLineData
c72a1d60
RP
1/*
2 * LED Class Core
3 *
4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
f8a7c6fe 5 * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
c72a1d60
RP
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
04713306
JA
12#include <linux/ctype.h>
13#include <linux/device.h>
14#include <linux/err.h>
c72a1d60 15#include <linux/init.h>
04713306
JA
16#include <linux/kernel.h>
17#include <linux/leds.h>
c72a1d60 18#include <linux/list.h>
04713306
JA
19#include <linux/module.h>
20#include <linux/slab.h>
c72a1d60 21#include <linux/spinlock.h>
9067359f 22#include <linux/timer.h>
eb1ce746 23#include <uapi/linux/uleds.h>
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24#include "leds.h"
25
26static struct class *leds_class;
27
5baa7503 28static ssize_t brightness_show(struct device *dev,
f8a7c6fe 29 struct device_attribute *attr, char *buf)
c72a1d60 30{
f8a7c6fe 31 struct led_classdev *led_cdev = dev_get_drvdata(dev);
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32
33 /* no lock needed for this */
29d76dfa 34 led_update_brightness(led_cdev);
c72a1d60 35
dd8e5a20 36 return sprintf(buf, "%u\n", led_cdev->brightness);
c72a1d60
RP
37}
38
5baa7503 39static ssize_t brightness_store(struct device *dev,
f8a7c6fe 40 struct device_attribute *attr, const char *buf, size_t size)
c72a1d60 41{
f8a7c6fe 42 struct led_classdev *led_cdev = dev_get_drvdata(dev);
872b86be 43 unsigned long state;
acd899e4
JA
44 ssize_t ret;
45
46 mutex_lock(&led_cdev->led_access);
47
48 if (led_sysfs_is_disabled(led_cdev)) {
49 ret = -EBUSY;
50 goto unlock;
51 }
c72a1d60 52
872b86be
SK
53 ret = kstrtoul(buf, 10, &state);
54 if (ret)
acd899e4 55 goto unlock;
3dc7b82e 56
872b86be
SK
57 if (state == LED_OFF)
58 led_trigger_remove(led_cdev);
4d71a4a1 59 led_set_brightness(led_cdev, state);
0013b23d 60
acd899e4
JA
61 ret = size;
62unlock:
63 mutex_unlock(&led_cdev->led_access);
64 return ret;
c72a1d60 65}
5baa7503 66static DEVICE_ATTR_RW(brightness);
c72a1d60 67
38419612 68static ssize_t max_brightness_show(struct device *dev,
1bd465e6
GL
69 struct device_attribute *attr, char *buf)
70{
71 struct led_classdev *led_cdev = dev_get_drvdata(dev);
72
73 return sprintf(buf, "%u\n", led_cdev->max_brightness);
74}
38419612 75static DEVICE_ATTR_RO(max_brightness);
1bd465e6 76
c3bc9956 77#ifdef CONFIG_LEDS_TRIGGERS
5baa7503
GKH
78static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
79static struct attribute *led_trigger_attrs[] = {
80 &dev_attr_trigger.attr,
81 NULL,
82};
83static const struct attribute_group led_trigger_group = {
84 .attrs = led_trigger_attrs,
85};
86#endif
87
88static struct attribute *led_class_attrs[] = {
89 &dev_attr_brightness.attr,
90 &dev_attr_max_brightness.attr,
91 NULL,
92};
93
94static const struct attribute_group led_group = {
95 .attrs = led_class_attrs,
96};
97
98static const struct attribute_group *led_groups[] = {
99 &led_group,
100#ifdef CONFIG_LEDS_TRIGGERS
101 &led_trigger_group,
c3bc9956 102#endif
5baa7503 103 NULL,
14b5d6dd 104};
c72a1d60 105
b8c5099b
HG
106#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
107static ssize_t brightness_hw_changed_show(struct device *dev,
108 struct device_attribute *attr, char *buf)
109{
110 struct led_classdev *led_cdev = dev_get_drvdata(dev);
111
112 if (led_cdev->brightness_hw_changed == -1)
113 return -ENODATA;
114
115 return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
116}
117
118static DEVICE_ATTR_RO(brightness_hw_changed);
119
120static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
121{
122 struct device *dev = led_cdev->dev;
123 int ret;
124
125 ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
126 if (ret) {
127 dev_err(dev, "Error creating brightness_hw_changed\n");
128 return ret;
129 }
130
131 led_cdev->brightness_hw_changed_kn =
132 sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
133 if (!led_cdev->brightness_hw_changed_kn) {
134 dev_err(dev, "Error getting brightness_hw_changed kn\n");
135 device_remove_file(dev, &dev_attr_brightness_hw_changed);
136 return -ENXIO;
137 }
138
139 return 0;
140}
141
142static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
143{
144 sysfs_put(led_cdev->brightness_hw_changed_kn);
145 device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
146}
147
148void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev,
149 enum led_brightness brightness)
150{
151 if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
152 return;
153
154 led_cdev->brightness_hw_changed = brightness;
155 sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
156}
157EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
158#else
159static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
160{
161 return 0;
162}
163static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
164{
165}
166#endif
167
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168/**
169 * led_classdev_suspend - suspend an led_classdev.
170 * @led_cdev: the led_classdev to suspend.
171 */
172void led_classdev_suspend(struct led_classdev *led_cdev)
173{
174 led_cdev->flags |= LED_SUSPENDED;
81fe8e5b 175 led_set_brightness_nopm(led_cdev, 0);
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RP
176}
177EXPORT_SYMBOL_GPL(led_classdev_suspend);
178
179/**
180 * led_classdev_resume - resume an led_classdev.
181 * @led_cdev: the led_classdev to resume.
182 */
183void led_classdev_resume(struct led_classdev *led_cdev)
184{
81fe8e5b 185 led_set_brightness_nopm(led_cdev, led_cdev->brightness);
7aea8389
JA
186
187 if (led_cdev->flash_resume)
188 led_cdev->flash_resume(led_cdev);
189
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190 led_cdev->flags &= ~LED_SUSPENDED;
191}
192EXPORT_SYMBOL_GPL(led_classdev_resume);
193
084609bf 194#ifdef CONFIG_PM_SLEEP
73e1ab41 195static int led_suspend(struct device *dev)
859cb7f2
RP
196{
197 struct led_classdev *led_cdev = dev_get_drvdata(dev);
198
199 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
200 led_classdev_suspend(led_cdev);
201
202 return 0;
203}
204
205static int led_resume(struct device *dev)
206{
207 struct led_classdev *led_cdev = dev_get_drvdata(dev);
208
209 if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
210 led_classdev_resume(led_cdev);
211
212 return 0;
213}
084609bf 214#endif
859cb7f2 215
084609bf 216static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
73e1ab41 217
a96aa64c
RRD
218static int match_name(struct device *dev, const void *data)
219{
220 if (!dev_name(dev))
221 return 0;
222 return !strcmp(dev_name(dev), (char *)data);
223}
224
225static int led_classdev_next_name(const char *init_name, char *name,
226 size_t len)
227{
228 unsigned int i = 0;
229 int ret = 0;
e5b5a61f 230 struct device *dev;
a96aa64c
RRD
231
232 strlcpy(name, init_name, len);
233
e5b5a61f
RRD
234 while ((ret < len) &&
235 (dev = class_find_device(leds_class, NULL, name, match_name))) {
236 put_device(dev);
a96aa64c 237 ret = snprintf(name, len, "%s_%u", init_name, ++i);
e5b5a61f 238 }
a96aa64c
RRD
239
240 if (ret >= len)
241 return -ENOMEM;
242
243 return i;
244}
245
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246/**
247 * led_classdev_register - register a new object of led_classdev class.
ff8649af 248 * @parent: The device to register.
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249 * @led_cdev: the led_classdev structure for this device.
250 */
251int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
252{
eb1ce746 253 char name[LED_MAX_NAME_SIZE];
a96aa64c
RRD
254 int ret;
255
256 ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
257 if (ret < 0)
258 return ret;
259
d0d480cc 260 led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
ccdc4507 261 led_cdev, led_cdev->groups, "%s", name);
801678c5 262 if (IS_ERR(led_cdev->dev))
f8a7c6fe 263 return PTR_ERR(led_cdev->dev);
c72a1d60 264
a96aa64c 265 if (ret)
6f06c7f8 266 dev_warn(parent, "Led %s renamed to %s due to name collision",
a96aa64c
RRD
267 led_cdev->name, dev_name(led_cdev->dev));
268
b8c5099b
HG
269 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
270 ret = led_add_brightness_hw_changed(led_cdev);
271 if (ret) {
272 device_unregister(led_cdev->dev);
273 return ret;
274 }
275 }
276
a9c6ce57 277 led_cdev->work_flags = 0;
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RP
278#ifdef CONFIG_LEDS_TRIGGERS
279 init_rwsem(&led_cdev->trigger_lock);
b8c5099b
HG
280#endif
281#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
282 led_cdev->brightness_hw_changed = -1;
270c3957 283#endif
acd899e4 284 mutex_init(&led_cdev->led_access);
c72a1d60 285 /* add to the list of leds */
72f8da32 286 down_write(&leds_list_lock);
c72a1d60 287 list_add_tail(&led_cdev->node, &leds_list);
72f8da32 288 up_write(&leds_list_lock);
c72a1d60 289
1bd465e6
GL
290 if (!led_cdev->max_brightness)
291 led_cdev->max_brightness = LED_FULL;
292
29d76dfa
HMH
293 led_update_brightness(led_cdev);
294
757b06ae 295 led_init_core(led_cdev);
5ada28bf 296
c3bc9956 297#ifdef CONFIG_LEDS_TRIGGERS
12fda168 298 led_trigger_set_default(led_cdev);
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RP
299#endif
300
d23e7b8b 301 dev_dbg(parent, "Registered led device: %s\n",
f8a7c6fe 302 led_cdev->name);
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303
304 return 0;
305}
306EXPORT_SYMBOL_GPL(led_classdev_register);
307
308/**
0266a458 309 * led_classdev_unregister - unregisters a object of led_properties class.
70d63ccc 310 * @led_cdev: the led device to unregister
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311 *
312 * Unregisters a previously registered via led_classdev_register object.
313 */
b844eba2 314void led_classdev_unregister(struct led_classdev *led_cdev)
c72a1d60 315{
c3bc9956 316#ifdef CONFIG_LEDS_TRIGGERS
dc47206e 317 down_write(&led_cdev->trigger_lock);
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RP
318 if (led_cdev->trigger)
319 led_trigger_set(led_cdev, NULL);
dc47206e 320 up_write(&led_cdev->trigger_lock);
c3bc9956 321#endif
c72a1d60 322
d84d80f3
HK
323 led_cdev->flags |= LED_UNREGISTERING;
324
5ada28bf 325 /* Stop blinking */
d23a22a7 326 led_stop_software_blink(led_cdev);
d1aa577f 327
19cd67e2 328 led_set_brightness(led_cdev, LED_OFF);
5ada28bf 329
d1aa577f
MK
330 flush_work(&led_cdev->set_brightness_work);
331
b8c5099b
HG
332 if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
333 led_remove_brightness_hw_changed(led_cdev);
334
b844eba2 335 device_unregister(led_cdev->dev);
c72a1d60 336
72f8da32 337 down_write(&leds_list_lock);
c72a1d60 338 list_del(&led_cdev->node);
72f8da32 339 up_write(&leds_list_lock);
acd899e4
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340
341 mutex_destroy(&led_cdev->led_access);
c72a1d60 342}
b844eba2 343EXPORT_SYMBOL_GPL(led_classdev_unregister);
c72a1d60 344
ca1bb4ee
BA
345static void devm_led_classdev_release(struct device *dev, void *res)
346{
347 led_classdev_unregister(*(struct led_classdev **)res);
348}
349
350/**
351 * devm_led_classdev_register - resource managed led_classdev_register()
352 * @parent: The device to register.
353 * @led_cdev: the led_classdev structure for this device.
354 */
355int devm_led_classdev_register(struct device *parent,
356 struct led_classdev *led_cdev)
357{
358 struct led_classdev **dr;
359 int rc;
360
361 dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
362 if (!dr)
363 return -ENOMEM;
364
365 rc = led_classdev_register(parent, led_cdev);
366 if (rc) {
367 devres_free(dr);
368 return rc;
369 }
370
371 *dr = led_cdev;
372 devres_add(parent, dr);
373
374 return 0;
375}
376EXPORT_SYMBOL_GPL(devm_led_classdev_register);
377
378static int devm_led_classdev_match(struct device *dev, void *res, void *data)
379{
380 struct led_cdev **p = res;
381
382 if (WARN_ON(!p || !*p))
383 return 0;
384
385 return *p == data;
386}
387
388/**
389 * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
390 * @parent: The device to unregister.
391 * @led_cdev: the led_classdev structure for this device.
392 */
393void devm_led_classdev_unregister(struct device *dev,
394 struct led_classdev *led_cdev)
395{
396 WARN_ON(devres_release(dev,
397 devm_led_classdev_release,
398 devm_led_classdev_match, led_cdev));
399}
400EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
401
c72a1d60
RP
402static int __init leds_init(void)
403{
404 leds_class = class_create(THIS_MODULE, "leds");
405 if (IS_ERR(leds_class))
406 return PTR_ERR(leds_class);
73e1ab41 407 leds_class->pm = &leds_class_dev_pm_ops;
5baa7503 408 leds_class->dev_groups = led_groups;
c72a1d60
RP
409 return 0;
410}
411
412static void __exit leds_exit(void)
413{
414 class_destroy(leds_class);
415}
416
417subsys_initcall(leds_init);
418module_exit(leds_exit);
419
420MODULE_AUTHOR("John Lenz, Richard Purdie");
421MODULE_LICENSE("GPL");
422MODULE_DESCRIPTION("LED Class Interface");