Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Backlight Lowlevel Control Abstraction | |
3 | * | |
4 | * Copyright (C) 2003,2004 Hewlett-Packard Company | |
5 | * | |
6 | */ | |
7 | ||
1da177e4 LT |
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> | |
1da177e4 | 16 | |
321709c5 RP |
17 | #ifdef CONFIG_PMAC_BACKLIGHT |
18 | #include <asm/backlight.h> | |
19 | #endif | |
3d5eeadd JS |
20 | |
21 | #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \ | |
22 | defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)) | |
23 | /* This callback gets called when something important happens inside a | |
24 | * framebuffer driver. We're looking if that important event is blanking, | |
25 | * and if it is, we're switching backlight power as well ... | |
26 | */ | |
27 | static 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 | /* If we aren't interested in this event, skip it immediately ... */ | |
994efacd | 34 | if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK) |
3d5eeadd JS |
35 | return 0; |
36 | ||
37 | bd = container_of(self, struct backlight_device, fb_notif); | |
599a52d1 RP |
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; | |
28ee086d | 43 | backlight_update_status(bd); |
3d5eeadd | 44 | } |
599a52d1 | 45 | mutex_unlock(&bd->ops_lock); |
3d5eeadd JS |
46 | return 0; |
47 | } | |
48 | ||
49 | static int backlight_register_fb(struct backlight_device *bd) | |
50 | { | |
51 | memset(&bd->fb_notif, 0, sizeof(bd->fb_notif)); | |
52 | bd->fb_notif.notifier_call = fb_notifier_callback; | |
53 | ||
54 | return fb_register_client(&bd->fb_notif); | |
55 | } | |
56 | ||
57 | static void backlight_unregister_fb(struct backlight_device *bd) | |
58 | { | |
59 | fb_unregister_client(&bd->fb_notif); | |
60 | } | |
61 | #else | |
62 | static inline int backlight_register_fb(struct backlight_device *bd) | |
63 | { | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static inline void backlight_unregister_fb(struct backlight_device *bd) | |
68 | { | |
69 | } | |
70 | #endif /* CONFIG_FB */ | |
71 | ||
1da177e4 LT |
72 | static ssize_t backlight_show_power(struct class_device *cdev, char *buf) |
73 | { | |
1da177e4 LT |
74 | struct backlight_device *bd = to_backlight_device(cdev); |
75 | ||
599a52d1 | 76 | return sprintf(buf, "%d\n", bd->props.power); |
1da177e4 LT |
77 | } |
78 | ||
79 | static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count) | |
80 | { | |
68673afd | 81 | int rc = -ENXIO; |
1da177e4 LT |
82 | char *endp; |
83 | struct backlight_device *bd = to_backlight_device(cdev); | |
68673afd RP |
84 | int power = simple_strtoul(buf, &endp, 0); |
85 | size_t size = endp - buf; | |
1da177e4 | 86 | |
68673afd RP |
87 | if (*endp && isspace(*endp)) |
88 | size++; | |
89 | if (size != count) | |
1da177e4 LT |
90 | return -EINVAL; |
91 | ||
599a52d1 RP |
92 | mutex_lock(&bd->ops_lock); |
93 | if (bd->ops) { | |
1da177e4 | 94 | pr_debug("backlight: set power to %d\n", power); |
599a52d1 | 95 | bd->props.power = power; |
28ee086d | 96 | backlight_update_status(bd); |
1da177e4 | 97 | rc = count; |
6ca01765 | 98 | } |
599a52d1 | 99 | mutex_unlock(&bd->ops_lock); |
1da177e4 LT |
100 | |
101 | return rc; | |
102 | } | |
103 | ||
104 | static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf) | |
105 | { | |
1da177e4 LT |
106 | struct backlight_device *bd = to_backlight_device(cdev); |
107 | ||
599a52d1 | 108 | return sprintf(buf, "%d\n", bd->props.brightness); |
1da177e4 LT |
109 | } |
110 | ||
111 | static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count) | |
112 | { | |
68673afd | 113 | int rc = -ENXIO; |
1da177e4 LT |
114 | char *endp; |
115 | struct backlight_device *bd = to_backlight_device(cdev); | |
68673afd RP |
116 | int brightness = simple_strtoul(buf, &endp, 0); |
117 | size_t size = endp - buf; | |
1da177e4 | 118 | |
68673afd RP |
119 | if (*endp && isspace(*endp)) |
120 | size++; | |
121 | if (size != count) | |
1da177e4 LT |
122 | return -EINVAL; |
123 | ||
599a52d1 RP |
124 | mutex_lock(&bd->ops_lock); |
125 | if (bd->ops) { | |
126 | if (brightness > bd->props.max_brightness) | |
6ca01765 RP |
127 | rc = -EINVAL; |
128 | else { | |
129 | pr_debug("backlight: set brightness to %d\n", | |
130 | brightness); | |
599a52d1 | 131 | bd->props.brightness = brightness; |
28ee086d | 132 | backlight_update_status(bd); |
6ca01765 RP |
133 | rc = count; |
134 | } | |
135 | } | |
599a52d1 | 136 | mutex_unlock(&bd->ops_lock); |
1da177e4 LT |
137 | |
138 | return rc; | |
139 | } | |
140 | ||
141 | static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf) | |
142 | { | |
1da177e4 LT |
143 | struct backlight_device *bd = to_backlight_device(cdev); |
144 | ||
599a52d1 | 145 | return sprintf(buf, "%d\n", bd->props.max_brightness); |
6ca01765 RP |
146 | } |
147 | ||
148 | static ssize_t backlight_show_actual_brightness(struct class_device *cdev, | |
149 | char *buf) | |
150 | { | |
151 | int rc = -ENXIO; | |
152 | struct backlight_device *bd = to_backlight_device(cdev); | |
153 | ||
599a52d1 RP |
154 | mutex_lock(&bd->ops_lock); |
155 | if (bd->ops && bd->ops->get_brightness) | |
156 | rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd)); | |
157 | mutex_unlock(&bd->ops_lock); | |
1da177e4 LT |
158 | |
159 | return rc; | |
160 | } | |
161 | ||
162 | static void backlight_class_release(struct class_device *dev) | |
163 | { | |
164 | struct backlight_device *bd = to_backlight_device(dev); | |
165 | kfree(bd); | |
166 | } | |
167 | ||
168 | static struct class backlight_class = { | |
169 | .name = "backlight", | |
170 | .release = backlight_class_release, | |
171 | }; | |
172 | ||
173 | #define DECLARE_ATTR(_name,_mode,_show,_store) \ | |
174 | { \ | |
7b595756 | 175 | .attr = { .name = __stringify(_name), .mode = _mode }, \ |
1da177e4 LT |
176 | .show = _show, \ |
177 | .store = _store, \ | |
178 | } | |
179 | ||
d95159cf | 180 | static const struct class_device_attribute bl_class_device_attributes[] = { |
1da177e4 | 181 | DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power), |
6ca01765 RP |
182 | DECLARE_ATTR(brightness, 0644, backlight_show_brightness, |
183 | backlight_store_brightness), | |
184 | DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness, | |
185 | NULL), | |
1da177e4 LT |
186 | DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL), |
187 | }; | |
188 | ||
1da177e4 LT |
189 | /** |
190 | * backlight_device_register - create and register a new object of | |
191 | * backlight_device class. | |
192 | * @name: the name of the new object(must be the same as the name of the | |
193 | * respective framebuffer device). | |
194 | * @devdata: an optional pointer to be stored in the class_device. The | |
195 | * methods may retrieve it by using class_get_devdata(&bd->class_dev). | |
599a52d1 | 196 | * @ops: the backlight operations structure. |
1da177e4 LT |
197 | * |
198 | * Creates and registers new backlight class_device. Returns either an | |
199 | * ERR_PTR() or a pointer to the newly allocated device. | |
200 | */ | |
519ab5f2 YL |
201 | struct backlight_device *backlight_device_register(const char *name, |
202 | struct device *dev, | |
203 | void *devdata, | |
599a52d1 | 204 | struct backlight_ops *ops) |
1da177e4 LT |
205 | { |
206 | int i, rc; | |
207 | struct backlight_device *new_bd; | |
208 | ||
209 | pr_debug("backlight_device_alloc: name=%s\n", name); | |
210 | ||
599a52d1 | 211 | new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL); |
90968e8e | 212 | if (!new_bd) |
10ad1b73 | 213 | return ERR_PTR(-ENOMEM); |
1da177e4 | 214 | |
28ee086d | 215 | mutex_init(&new_bd->update_lock); |
599a52d1 RP |
216 | mutex_init(&new_bd->ops_lock); |
217 | new_bd->ops = ops; | |
1da177e4 | 218 | new_bd->class_dev.class = &backlight_class; |
519ab5f2 | 219 | new_bd->class_dev.dev = dev; |
1da177e4 LT |
220 | strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN); |
221 | class_set_devdata(&new_bd->class_dev, devdata); | |
222 | ||
223 | rc = class_device_register(&new_bd->class_dev); | |
90968e8e | 224 | if (rc) { |
2fd5a154 | 225 | kfree(new_bd); |
1da177e4 LT |
226 | return ERR_PTR(rc); |
227 | } | |
228 | ||
3d5eeadd | 229 | rc = backlight_register_fb(new_bd); |
2fd5a154 DT |
230 | if (rc) { |
231 | class_device_unregister(&new_bd->class_dev); | |
232 | return ERR_PTR(rc); | |
233 | } | |
234 | ||
1da177e4 LT |
235 | |
236 | for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) { | |
237 | rc = class_device_create_file(&new_bd->class_dev, | |
238 | &bl_class_device_attributes[i]); | |
90968e8e | 239 | if (rc) { |
1da177e4 LT |
240 | while (--i >= 0) |
241 | class_device_remove_file(&new_bd->class_dev, | |
242 | &bl_class_device_attributes[i]); | |
243 | class_device_unregister(&new_bd->class_dev); | |
244 | /* No need to kfree(new_bd) since release() method was called */ | |
245 | return ERR_PTR(rc); | |
246 | } | |
247 | } | |
248 | ||
321709c5 RP |
249 | #ifdef CONFIG_PMAC_BACKLIGHT |
250 | mutex_lock(&pmac_backlight_mutex); | |
251 | if (!pmac_backlight) | |
252 | pmac_backlight = new_bd; | |
253 | mutex_unlock(&pmac_backlight_mutex); | |
254 | #endif | |
255 | ||
1da177e4 LT |
256 | return new_bd; |
257 | } | |
258 | EXPORT_SYMBOL(backlight_device_register); | |
259 | ||
260 | /** | |
261 | * backlight_device_unregister - unregisters a backlight device object. | |
262 | * @bd: the backlight device object to be unregistered and freed. | |
263 | * | |
264 | * Unregisters a previously registered via backlight_device_register object. | |
265 | */ | |
266 | void backlight_device_unregister(struct backlight_device *bd) | |
267 | { | |
268 | int i; | |
269 | ||
270 | if (!bd) | |
271 | return; | |
272 | ||
273 | pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id); | |
274 | ||
321709c5 RP |
275 | #ifdef CONFIG_PMAC_BACKLIGHT |
276 | mutex_lock(&pmac_backlight_mutex); | |
277 | if (pmac_backlight == bd) | |
278 | pmac_backlight = NULL; | |
279 | mutex_unlock(&pmac_backlight_mutex); | |
280 | #endif | |
281 | ||
1da177e4 LT |
282 | for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) |
283 | class_device_remove_file(&bd->class_dev, | |
284 | &bl_class_device_attributes[i]); | |
285 | ||
599a52d1 RP |
286 | mutex_lock(&bd->ops_lock); |
287 | bd->ops = NULL; | |
288 | mutex_unlock(&bd->ops_lock); | |
1da177e4 | 289 | |
3d5eeadd | 290 | backlight_unregister_fb(bd); |
1da177e4 LT |
291 | |
292 | class_device_unregister(&bd->class_dev); | |
293 | } | |
294 | EXPORT_SYMBOL(backlight_device_unregister); | |
295 | ||
296 | static void __exit backlight_class_exit(void) | |
297 | { | |
298 | class_unregister(&backlight_class); | |
299 | } | |
300 | ||
301 | static int __init backlight_class_init(void) | |
302 | { | |
303 | return class_register(&backlight_class); | |
304 | } | |
305 | ||
306 | /* | |
307 | * if this is compiled into the kernel, we need to ensure that the | |
308 | * class is registered before users of the class try to register lcd's | |
309 | */ | |
310 | postcore_initcall(backlight_class_init); | |
311 | module_exit(backlight_class_exit); | |
312 | ||
313 | MODULE_LICENSE("GPL"); | |
314 | MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>"); | |
315 | MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction"); |