xref: /linux/include/linux/lcd.h (revision 1da177e4)
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>
12 #include <linux/notifier.h>
13 
14 struct lcd_device;
15 struct fb_info;
16 
17 /* This structure defines all the properties of a LCD flat panel. */
18 struct lcd_properties {
19 	/* Owner module */
20 	struct module *owner;
21 	/* Get the LCD panel power status (0: full on, 1..3: controller
22 	   power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
23 	int (*get_power)(struct lcd_device *);
24 	/* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
25 	int (*set_power)(struct lcd_device *, int power);
26 	/* The maximum value for contrast (read-only) */
27 	int max_contrast;
28 	/* Get the current contrast setting (0-max_contrast) */
29 	int (*get_contrast)(struct lcd_device *);
30 	/* Set LCD panel contrast */
31         int (*set_contrast)(struct lcd_device *, int contrast);
32 	/* Check if given framebuffer device is the one LCD is bound to;
33 	   return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */
34 	int (*check_fb)(struct fb_info *);
35 };
36 
37 struct lcd_device {
38 	/* This protects the 'props' field. If 'props' is NULL, the driver that
39 	   registered this device has been unloaded, and if class_get_devdata()
40 	   points to something in the body of that driver, it is also invalid. */
41 	struct semaphore sem;
42 	/* If this is NULL, the backing module is unloaded */
43 	struct lcd_properties *props;
44 	/* The framebuffer notifier block */
45 	struct notifier_block fb_notif;
46 	/* The class device structure */
47 	struct class_device class_dev;
48 };
49 
50 extern struct lcd_device *lcd_device_register(const char *name,
51 	void *devdata, struct lcd_properties *lp);
52 extern void lcd_device_unregister(struct lcd_device *ld);
53 
54 #define to_lcd_device(obj) container_of(obj, struct lcd_device, class_dev)
55 
56 #endif
57