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	/*
44	 * Enable or disable power to the LCD(0: on; 4: off, see FB_BLANK_XXX)
45	 * and this callback would be called proir to fb driver's callback.
46	 *
47	 * P.S. note that if early_set_power is not NULL then early fb notifier
48	 *	would be registered.
49	 */
50	int (*early_set_power)(struct lcd_device *, int power);
51	/* revert the effects of the early blank event. */
52	int (*r_early_set_power)(struct lcd_device *, int power);
53	/* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
54	int (*set_power)(struct lcd_device *, int power);
55	/* Get the current contrast setting (0-max_contrast) */
56	int (*get_contrast)(struct lcd_device *);
57	/* Set LCD panel contrast */
58        int (*set_contrast)(struct lcd_device *, int contrast);
59	/* Set LCD panel mode (resolutions ...) */
60	int (*set_mode)(struct lcd_device *, struct fb_videomode *);
61	/* Check if given framebuffer device is the one LCD is bound to;
62	   return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */
63	int (*check_fb)(struct lcd_device *, struct fb_info *);
64};
65
66struct lcd_device {
67	struct lcd_properties props;
68	/* This protects the 'ops' field. If 'ops' is NULL, the driver that
69	   registered this device has been unloaded, and if class_get_devdata()
70	   points to something in the body of that driver, it is also invalid. */
71	struct mutex ops_lock;
72	/* If this is NULL, the backing module is unloaded */
73	struct lcd_ops *ops;
74	/* Serialise access to set_power method */
75	struct mutex update_lock;
76	/* The framebuffer notifier block */
77	struct notifier_block fb_notif;
78
79	struct device dev;
80};
81
82struct lcd_platform_data {
83	/* reset lcd panel device. */
84	int (*reset)(struct lcd_device *ld);
85	/* on or off to lcd panel. if 'enable' is 0 then
86	   lcd power off and 1, lcd power on. */
87	int (*power_on)(struct lcd_device *ld, int enable);
88
89	/* it indicates whether lcd panel was enabled
90	   from bootloader or not. */
91	int lcd_enabled;
92	/* it means delay for stable time when it becomes low to high
93	   or high to low that is dependent on whether reset gpio is
94	   low active or high active. */
95	unsigned int reset_delay;
96	/* stable time needing to become lcd power on. */
97	unsigned int power_on_delay;
98	/* stable time needing to become lcd power off. */
99	unsigned int power_off_delay;
100
101	/* it could be used for any purpose. */
102	void *pdata;
103};
104
105static inline void lcd_set_power(struct lcd_device *ld, int power)
106{
107	mutex_lock(&ld->update_lock);
108	if (ld->ops && ld->ops->set_power)
109		ld->ops->set_power(ld, power);
110	mutex_unlock(&ld->update_lock);
111}
112
113extern struct lcd_device *lcd_device_register(const char *name,
114	struct device *parent, void *devdata, struct lcd_ops *ops);
115extern struct lcd_device *devm_lcd_device_register(struct device *dev,
116	const char *name, struct device *parent,
117	void *devdata, struct lcd_ops *ops);
118extern void lcd_device_unregister(struct lcd_device *ld);
119extern void devm_lcd_device_unregister(struct device *dev,
120	struct lcd_device *ld);
121
122#define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)
123
124static inline void * lcd_get_data(struct lcd_device *ld_dev)
125{
126	return dev_get_drvdata(&ld_dev->dev);
127}
128
129
130#endif
131