aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/lcd.h
blob: 851eee8fff257836c06ed5b8b7f4ddb7d0e87e2a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * LCD Lowlevel Control Abstraction
 *
 * Copyright (C) 2003,2004 Hewlett-Packard Company
 *
 */

#ifndef _LINUX_LCD_H
#define _LINUX_LCD_H

#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/fb.h>

/* Notes on locking:
 *
 * lcd_device->ops_lock is an internal backlight lock protecting the ops
 * field and no code outside the core should need to touch it.
 *
 * Access to set_power() is serialised by the update_lock mutex since
 * most drivers seem to need this and historically get it wrong.
 *
 * Most drivers don't need locking on their get_power() method.
 * If yours does, you need to implement it in the driver. You can use the
 * update_lock mutex if appropriate.
 *
 * Any other use of the locks below is probably wrong.
 */

struct lcd_device;
struct fb_info;

struct lcd_properties {
	/* The maximum value for contrast (read-only) */
	int max_contrast;
};

struct lcd_ops {
	/* Get the LCD panel power status (0: full on, 1..3: controller
	   power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
	int (*get_power)(struct lcd_device *);
	/*
	 * Enable or disable power to the LCD(0: on; 4: off, see FB_BLANK_XXX)
	 * and this callback would be called proir to fb driver's callback.
	 *
	 * P.S. note that if early_set_power is not NULL then early fb notifier
	 *	would be registered.
	 */
	int (*early_set_power)(struct lcd_device *, int power);
	/* revert the effects of the early blank event. */
	int (*r_early_set_power)(struct lcd_device *, int power);
	/* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
	int (*set_power)(struct lcd_device *, int power);
	/* Get the current contrast setting (0-max_contrast) */
	int (*get_contrast)(struct lcd_device *);
	/* Set LCD panel contrast */
        int (*set_contrast)(struct lcd_device *, int contrast);
	/* Set LCD panel mode (resolutions ...) */
	int (*set_mode)(struct lcd_device *, struct fb_videomode *);
	/* Check if given framebuffer device is the one LCD is bound to;
	   return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */
	int (*check_fb)(struct lcd_device *, struct fb_info *);
};

struct lcd_device {
	struct lcd_properties props;
	/* This protects the 'ops' field. If 'ops' is NULL, the driver that
	   registered this device has been unloaded, and if class_get_devdata()
	   points to something in the body of that driver, it is also invalid. */
	struct mutex ops_lock;
	/* If this is NULL, the backing module is unloaded */
	struct lcd_ops *ops;
	/* Serialise access to set_power method */
	struct mutex update_lock;
	/* The framebuffer notifier block */
	struct notifier_block fb_notif;

	struct device dev;
};

struct lcd_platform_data {
	/* reset lcd panel device. */
	int (*reset)(struct lcd_device *ld);
	/* on or off to lcd panel. if 'enable' is 0 then
	   lcd power off and 1, lcd power on. */
	int (*power_on)(struct lcd_device *ld, int enable);

	/* it indicates whether lcd panel was enabled
	   from bootloader or not. */
	int lcd_enabled;
	/* it means delay for stable time when it becomes low to high
	   or high to low that is dependent on whether reset gpio is
	   low active or high active. */
	unsigned int reset_delay;
	/* stable time needing to become lcd power on. */
	unsigned int power_on_delay;
	/* stable time needing to become lcd power off. */
	unsigned int power_off_delay;

	/* it could be used for any purpose. */
	void *pdata;
};

static inline void lcd_set_power(struct lcd_device *ld, int power)
{
	mutex_lock(&ld->update_lock);
	if (ld->ops && ld->ops->set_power)
		ld->ops->set_power(ld, power);
	mutex_unlock(&ld->update_lock);
}

extern struct lcd_device *lcd_device_register(const char *name,
	struct device *parent, void *devdata, struct lcd_ops *ops);
extern struct lcd_device *devm_lcd_device_register(struct device *dev,
	const char *name, struct device *parent,
	void *devdata, struct lcd_ops *ops);
extern void lcd_device_unregister(struct lcd_device *ld);
extern void devm_lcd_device_unregister(struct device *dev,
	struct lcd_device *ld);

#define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)

static inline void * lcd_get_data(struct lcd_device *ld_dev)
{
	return dev_get_drvdata(&ld_dev->dev);
}


#endif