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/mutex.h>
13#include <linux/notifier.h>
14#include <linux/fb.h>
15
16/* Notes on locking:
17 *
18 * lcd_device->ops_lock is an internal backlight lock protecting the ops
19 * field and no code outside the core should need to touch it.
20 *
21 * Access to set_power() is serialised by the update_lock mutex since
22 * most drivers seem to need this and historically get it wrong.
23 *
24 * Most drivers don't need locking on their get_power() method.
25 * If yours does, you need to implement it in the driver. You can use the
26 * update_lock mutex if appropriate.
27 *
28 * Any other use of the locks below is probably wrong.
29 */
30
31struct lcd_device;
32struct fb_info;
33
34struct lcd_properties {
35	/* The maximum value for contrast (read-only) */
36	int max_contrast;
37};
38
39struct lcd_ops {
40	/* Get the LCD panel power status (0: full on, 1..3: controller
41	   power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
42	int (*get_power)(struct lcd_device *);
43	/* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
44	int (*set_power)(struct lcd_device *, int power);
45	/* Get the current contrast setting (0-max_contrast) */
46	int (*get_contrast)(struct lcd_device *);
47	/* Set LCD panel contrast */
48        int (*set_contrast)(struct lcd_device *, int contrast);
49	/* Set LCD panel mode (resolutions ...) */
50	int (*set_mode)(struct lcd_device *, struct fb_videomode *);
51	/* Check if given framebuffer device is the one LCD is bound to;
52	   return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */
53	int (*check_fb)(struct lcd_device *, struct fb_info *);
54};
55
56struct lcd_device {
57	struct lcd_properties props;
58	/* This protects the 'ops' field. If 'ops' is NULL, the driver that
59	   registered this device has been unloaded, and if class_get_devdata()
60	   points to something in the body of that driver, it is also invalid. */
61	struct mutex ops_lock;
62	/* If this is NULL, the backing module is unloaded */
63	struct lcd_ops *ops;
64	/* Serialise access to set_power method */
65	struct mutex update_lock;
66	/* The framebuffer notifier block */
67	struct notifier_block fb_notif;
68
69	struct device dev;
70};
71
72struct lcd_platform_data {
73	/* reset lcd panel device. */
74	int (*reset)(struct lcd_device *ld);
75	/* on or off to lcd panel. if 'enable' is 0 then
76	   lcd power off and 1, lcd power on. */
77	int (*power_on)(struct lcd_device *ld, int enable);
78
79	/* it indicates whether lcd panel was enabled
80	   from bootloader or not. */
81	int lcd_enabled;
82	/* it means delay for stable time when it becomes low to high
83	   or high to low that is dependent on whether reset gpio is
84	   low active or high active. */
85	unsigned int reset_delay;
86	/* stable time needing to become lcd power on. */
87	unsigned int power_on_delay;
88	/* stable time needing to become lcd power off. */
89	unsigned int power_off_delay;
90
91	/* it could be used for any purpose. */
92	void *pdata;
93};
94
95static inline void lcd_set_power(struct lcd_device *ld, int power)
96{
97	mutex_lock(&ld->update_lock);
98	if (ld->ops && ld->ops->set_power)
99		ld->ops->set_power(ld, power);
100	mutex_unlock(&ld->update_lock);
101}
102
103extern struct lcd_device *lcd_device_register(const char *name,
104	struct device *parent, void *devdata, struct lcd_ops *ops);
105extern void lcd_device_unregister(struct lcd_device *ld);
106
107#define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)
108
109static inline void * lcd_get_data(struct lcd_device *ld_dev)
110{
111	return dev_get_drvdata(&ld_dev->dev);
112}
113
114
115#endif
116