Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * LCD Lowlevel Control Abstraction | |
3 | * | |
4 | * Copyright (C) 2003,2004 Hewlett-Packard Company | |
5 | * | |
6 | */ | |
7 | ||
8 | #ifndef _LINUX_LCD_H | |
9 | #define _LINUX_LCD_H | |
10 | ||
11 | #include <linux/device.h> | |
28ee086d | 12 | #include <linux/mutex.h> |
1da177e4 LT |
13 | #include <linux/notifier.h> |
14 | ||
28ee086d RP |
15 | /* Notes on locking: |
16 | * | |
249040dc | 17 | * lcd_device->props_lock is an internal backlight lock protecting the props |
28ee086d RP |
18 | * field and no code outside the core should need to touch it. |
19 | * | |
20 | * Access to set_power() is serialised by the update_lock mutex since | |
21 | * most drivers seem to need this and historically get it wrong. | |
22 | * | |
23 | * Most drivers don't need locking on their get_power() method. | |
24 | * If yours does, you need to implement it in the driver. You can use the | |
25 | * update_lock mutex if appropriate. | |
26 | * | |
27 | * Any other use of the locks below is probably wrong. | |
28 | */ | |
29 | ||
1da177e4 LT |
30 | struct lcd_device; |
31 | struct fb_info; | |
32 | ||
33 | /* This structure defines all the properties of a LCD flat panel. */ | |
34 | struct lcd_properties { | |
1da177e4 LT |
35 | /* Get the LCD panel power status (0: full on, 1..3: controller |
36 | power on, flat panel power off, 4: full off), see FB_BLANK_XXX */ | |
37 | int (*get_power)(struct lcd_device *); | |
38 | /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */ | |
39 | int (*set_power)(struct lcd_device *, int power); | |
40 | /* The maximum value for contrast (read-only) */ | |
41 | int max_contrast; | |
42 | /* Get the current contrast setting (0-max_contrast) */ | |
43 | int (*get_contrast)(struct lcd_device *); | |
44 | /* Set LCD panel contrast */ | |
45 | int (*set_contrast)(struct lcd_device *, int contrast); | |
46 | /* Check if given framebuffer device is the one LCD is bound to; | |
47 | return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */ | |
48 | int (*check_fb)(struct fb_info *); | |
49 | }; | |
50 | ||
51 | struct lcd_device { | |
52 | /* This protects the 'props' field. If 'props' is NULL, the driver that | |
53 | registered this device has been unloaded, and if class_get_devdata() | |
54 | points to something in the body of that driver, it is also invalid. */ | |
249040dc | 55 | struct mutex props_lock; |
1da177e4 LT |
56 | /* If this is NULL, the backing module is unloaded */ |
57 | struct lcd_properties *props; | |
28ee086d RP |
58 | /* Serialise access to set_power method */ |
59 | struct mutex update_lock; | |
1da177e4 LT |
60 | /* The framebuffer notifier block */ |
61 | struct notifier_block fb_notif; | |
62 | /* The class device structure */ | |
63 | struct class_device class_dev; | |
64 | }; | |
65 | ||
28ee086d RP |
66 | static inline void lcd_set_power(struct lcd_device *ld, int power) |
67 | { | |
68 | mutex_lock(&ld->update_lock); | |
69 | if (ld->props && ld->props->set_power) | |
70 | ld->props->set_power(ld, power); | |
71 | mutex_unlock(&ld->update_lock); | |
72 | } | |
73 | ||
1da177e4 LT |
74 | extern struct lcd_device *lcd_device_register(const char *name, |
75 | void *devdata, struct lcd_properties *lp); | |
76 | extern void lcd_device_unregister(struct lcd_device *ld); | |
77 | ||
78 | #define to_lcd_device(obj) container_of(obj, struct lcd_device, class_dev) | |
79 | ||
80 | #endif |