1
2
3
4
5
6
7
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/device.h>
11#include <linux/backlight.h>
12#include <linux/notifier.h>
13#include <linux/ctype.h>
14#include <linux/err.h>
15#include <linux/fb.h>
16
17#ifdef CONFIG_PMAC_BACKLIGHT
18#include <asm/backlight.h>
19#endif
20
21#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
22 defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
23
24
25
26
27static int fb_notifier_callback(struct notifier_block *self,
28 unsigned long event, void *data)
29{
30 struct backlight_device *bd;
31 struct fb_event *evdata = data;
32
33
34 if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
35 return 0;
36
37 bd = container_of(self, struct backlight_device, fb_notif);
38 mutex_lock(&bd->ops_lock);
39 if (bd->ops)
40 if (!bd->ops->check_fb ||
41 bd->ops->check_fb(evdata->info)) {
42 bd->props.fb_blank = *(int *)evdata->data;
43 if (bd->props.fb_blank == FB_BLANK_UNBLANK)
44 bd->props.state &= ~BL_CORE_FBBLANK;
45 else
46 bd->props.state |= BL_CORE_FBBLANK;
47 backlight_update_status(bd);
48 }
49 mutex_unlock(&bd->ops_lock);
50 return 0;
51}
52
53static int backlight_register_fb(struct backlight_device *bd)
54{
55 memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
56 bd->fb_notif.notifier_call = fb_notifier_callback;
57
58 return fb_register_client(&bd->fb_notif);
59}
60
61static void backlight_unregister_fb(struct backlight_device *bd)
62{
63 fb_unregister_client(&bd->fb_notif);
64}
65#else
66static inline int backlight_register_fb(struct backlight_device *bd)
67{
68 return 0;
69}
70
71static inline void backlight_unregister_fb(struct backlight_device *bd)
72{
73}
74#endif
75
76static void backlight_generate_event(struct backlight_device *bd,
77 enum backlight_update_reason reason)
78{
79 char *envp[2];
80
81 switch (reason) {
82 case BACKLIGHT_UPDATE_SYSFS:
83 envp[0] = "SOURCE=sysfs";
84 break;
85 case BACKLIGHT_UPDATE_HOTKEY:
86 envp[0] = "SOURCE=hotkey";
87 break;
88 default:
89 envp[0] = "SOURCE=unknown";
90 break;
91 }
92 envp[1] = NULL;
93 kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp);
94 sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness");
95}
96
97static ssize_t backlight_show_power(struct device *dev,
98 struct device_attribute *attr,char *buf)
99{
100 struct backlight_device *bd = to_backlight_device(dev);
101
102 return sprintf(buf, "%d\n", bd->props.power);
103}
104
105static ssize_t backlight_store_power(struct device *dev,
106 struct device_attribute *attr, const char *buf, size_t count)
107{
108 int rc;
109 struct backlight_device *bd = to_backlight_device(dev);
110 unsigned long power;
111
112 rc = strict_strtoul(buf, 0, &power);
113 if (rc)
114 return rc;
115
116 rc = -ENXIO;
117 mutex_lock(&bd->ops_lock);
118 if (bd->ops) {
119 pr_debug("backlight: set power to %lu\n", power);
120 if (bd->props.power != power) {
121 bd->props.power = power;
122 backlight_update_status(bd);
123 }
124 rc = count;
125 }
126 mutex_unlock(&bd->ops_lock);
127
128 return rc;
129}
130
131static ssize_t backlight_show_brightness(struct device *dev,
132 struct device_attribute *attr, char *buf)
133{
134 struct backlight_device *bd = to_backlight_device(dev);
135
136 return sprintf(buf, "%d\n", bd->props.brightness);
137}
138
139static ssize_t backlight_store_brightness(struct device *dev,
140 struct device_attribute *attr, const char *buf, size_t count)
141{
142 int rc;
143 struct backlight_device *bd = to_backlight_device(dev);
144 unsigned long brightness;
145
146 rc = strict_strtoul(buf, 0, &brightness);
147 if (rc)
148 return rc;
149
150 rc = -ENXIO;
151
152 mutex_lock(&bd->ops_lock);
153 if (bd->ops) {
154 if (brightness > bd->props.max_brightness)
155 rc = -EINVAL;
156 else {
157 pr_debug("backlight: set brightness to %lu\n",
158 brightness);
159 bd->props.brightness = brightness;
160 backlight_update_status(bd);
161 rc = count;
162 }
163 }
164 mutex_unlock(&bd->ops_lock);
165
166 backlight_generate_event(bd, BACKLIGHT_UPDATE_SYSFS);
167
168 return rc;
169}
170
171static ssize_t backlight_show_max_brightness(struct device *dev,
172 struct device_attribute *attr, char *buf)
173{
174 struct backlight_device *bd = to_backlight_device(dev);
175
176 return sprintf(buf, "%d\n", bd->props.max_brightness);
177}
178
179static ssize_t backlight_show_actual_brightness(struct device *dev,
180 struct device_attribute *attr, char *buf)
181{
182 int rc = -ENXIO;
183 struct backlight_device *bd = to_backlight_device(dev);
184
185 mutex_lock(&bd->ops_lock);
186 if (bd->ops && bd->ops->get_brightness)
187 rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
188 mutex_unlock(&bd->ops_lock);
189
190 return rc;
191}
192
193static struct class *backlight_class;
194
195static int backlight_suspend(struct device *dev, pm_message_t state)
196{
197 struct backlight_device *bd = to_backlight_device(dev);
198
199 if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
200 mutex_lock(&bd->ops_lock);
201 bd->props.state |= BL_CORE_SUSPENDED;
202 backlight_update_status(bd);
203 mutex_unlock(&bd->ops_lock);
204 }
205
206 return 0;
207}
208
209static int backlight_resume(struct device *dev)
210{
211 struct backlight_device *bd = to_backlight_device(dev);
212
213 if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
214 mutex_lock(&bd->ops_lock);
215 bd->props.state &= ~BL_CORE_SUSPENDED;
216 backlight_update_status(bd);
217 mutex_unlock(&bd->ops_lock);
218 }
219
220 return 0;
221}
222
223static void bl_device_release(struct device *dev)
224{
225 struct backlight_device *bd = to_backlight_device(dev);
226 kfree(bd);
227}
228
229static struct device_attribute bl_device_attributes[] = {
230 __ATTR(bl_power, 0644, backlight_show_power, backlight_store_power),
231 __ATTR(brightness, 0644, backlight_show_brightness,
232 backlight_store_brightness),
233 __ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
234 NULL),
235 __ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
236 __ATTR_NULL,
237};
238
239
240
241
242
243
244
245
246
247void backlight_force_update(struct backlight_device *bd,
248 enum backlight_update_reason reason)
249{
250 mutex_lock(&bd->ops_lock);
251 if (bd->ops && bd->ops->get_brightness)
252 bd->props.brightness = bd->ops->get_brightness(bd);
253 mutex_unlock(&bd->ops_lock);
254 backlight_generate_event(bd, reason);
255}
256EXPORT_SYMBOL(backlight_force_update);
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271struct backlight_device *backlight_device_register(const char *name,
272 struct device *parent, void *devdata, struct backlight_ops *ops)
273{
274 struct backlight_device *new_bd;
275 int rc;
276
277 pr_debug("backlight_device_register: name=%s\n", name);
278
279 new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
280 if (!new_bd)
281 return ERR_PTR(-ENOMEM);
282
283 mutex_init(&new_bd->update_lock);
284 mutex_init(&new_bd->ops_lock);
285
286 new_bd->dev.class = backlight_class;
287 new_bd->dev.parent = parent;
288 new_bd->dev.release = bl_device_release;
289 dev_set_name(&new_bd->dev, name);
290 dev_set_drvdata(&new_bd->dev, devdata);
291
292 rc = device_register(&new_bd->dev);
293 if (rc) {
294 kfree(new_bd);
295 return ERR_PTR(rc);
296 }
297
298 rc = backlight_register_fb(new_bd);
299 if (rc) {
300 device_unregister(&new_bd->dev);
301 return ERR_PTR(rc);
302 }
303
304 new_bd->ops = ops;
305
306#ifdef CONFIG_PMAC_BACKLIGHT
307 mutex_lock(&pmac_backlight_mutex);
308 if (!pmac_backlight)
309 pmac_backlight = new_bd;
310 mutex_unlock(&pmac_backlight_mutex);
311#endif
312
313 return new_bd;
314}
315EXPORT_SYMBOL(backlight_device_register);
316
317
318
319
320
321
322
323void backlight_device_unregister(struct backlight_device *bd)
324{
325 if (!bd)
326 return;
327
328#ifdef CONFIG_PMAC_BACKLIGHT
329 mutex_lock(&pmac_backlight_mutex);
330 if (pmac_backlight == bd)
331 pmac_backlight = NULL;
332 mutex_unlock(&pmac_backlight_mutex);
333#endif
334 mutex_lock(&bd->ops_lock);
335 bd->ops = NULL;
336 mutex_unlock(&bd->ops_lock);
337
338 backlight_unregister_fb(bd);
339 device_unregister(&bd->dev);
340}
341EXPORT_SYMBOL(backlight_device_unregister);
342
343static void __exit backlight_class_exit(void)
344{
345 class_destroy(backlight_class);
346}
347
348static int __init backlight_class_init(void)
349{
350 backlight_class = class_create(THIS_MODULE, "backlight");
351 if (IS_ERR(backlight_class)) {
352 printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
353 PTR_ERR(backlight_class));
354 return PTR_ERR(backlight_class);
355 }
356
357 backlight_class->dev_attrs = bl_device_attributes;
358 backlight_class->suspend = backlight_suspend;
359 backlight_class->resume = backlight_resume;
360 return 0;
361}
362
363
364
365
366
367postcore_initcall(backlight_class_init);
368module_exit(backlight_class_exit);
369
370MODULE_LICENSE("GPL");
371MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
372MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");
373