1 /* SPDX-License-Identifier: GPL-2.0 */ 1
2 /*
3 * LCD Lowlevel Control Abstraction
4 *
5 * Copyright (C) 2003,2004 Hewlett-Packard Com
6 *
7 */
8
9 #ifndef _LINUX_LCD_H
10 #define _LINUX_LCD_H
11
12 #include <linux/device.h>
13 #include <linux/mutex.h>
14 #include <linux/notifier.h>
15 #include <linux/fb.h>
16
17 /* Notes on locking:
18 *
19 * lcd_device->ops_lock is an internal backlig
20 * field and no code outside the core should n
21 *
22 * Access to set_power() is serialised by the
23 * most drivers seem to need this and historic
24 *
25 * Most drivers don't need locking on their ge
26 * If yours does, you need to implement it in
27 * update_lock mutex if appropriate.
28 *
29 * Any other use of the locks below is probabl
30 */
31
32 struct lcd_device;
33 struct fb_info;
34
35 struct lcd_properties {
36 /* The maximum value for contrast (rea
37 int max_contrast;
38 };
39
40 struct lcd_ops {
41 /* Get the LCD panel power status (0:
42 power on, flat panel power off, 4:
43 int (*get_power)(struct lcd_device *);
44 /* Enable or disable power to the LCD
45 int (*set_power)(struct lcd_device *,
46 /* Get the current contrast setting (0
47 int (*get_contrast)(struct lcd_device
48 /* Set LCD panel contrast */
49 int (*set_contrast)(struct lcd_device
50 /* Set LCD panel mode (resolutions ...
51 int (*set_mode)(struct lcd_device *, s
52 /* Check if given framebuffer device i
53 return 0 if not, !=0 if it is. If N
54 int (*check_fb)(struct lcd_device *, s
55 };
56
57 struct lcd_device {
58 struct lcd_properties props;
59 /* This protects the 'ops' field. If '
60 registered this device has been unl
61 points to something in the body of
62 struct mutex ops_lock;
63 /* If this is NULL, the backing module
64 const struct lcd_ops *ops;
65 /* Serialise access to set_power metho
66 struct mutex update_lock;
67 /* The framebuffer notifier block */
68 struct notifier_block fb_notif;
69
70 struct device dev;
71 };
72
73 struct lcd_platform_data {
74 /* reset lcd panel device. */
75 int (*reset)(struct lcd_device *ld);
76 /* on or off to lcd panel. if 'enable'
77 lcd power off and 1, lcd power on.
78 int (*power_on)(struct lcd_device *ld,
79
80 /* it indicates whether lcd panel was
81 from bootloader or not. */
82 int lcd_enabled;
83 /* it means delay for stable time when
84 or high to low that is dependent on
85 low active or high active. */
86 unsigned int reset_delay;
87 /* stable time needing to become lcd p
88 unsigned int power_on_delay;
89 /* stable time needing to become lcd p
90 unsigned int power_off_delay;
91
92 /* it could be used for any purpose. *
93 void *pdata;
94 };
95
96 static inline void lcd_set_power(struct lcd_de
97 {
98 mutex_lock(&ld->update_lock);
99 if (ld->ops && ld->ops->set_power)
100 ld->ops->set_power(ld, power);
101 mutex_unlock(&ld->update_lock);
102 }
103
104 extern struct lcd_device *lcd_device_register(
105 struct device *parent, void *devdata,
106 extern struct lcd_device *devm_lcd_device_regi
107 const char *name, struct device *paren
108 void *devdata, const struct lcd_ops *o
109 extern void lcd_device_unregister(struct lcd_d
110 extern void devm_lcd_device_unregister(struct
111 struct lcd_device *ld);
112
113 #define to_lcd_device(obj) container_of(obj, s
114
115 static inline void * lcd_get_data(struct lcd_d
116 {
117 return dev_get_drvdata(&ld_dev->dev);
118 }
119
120
121 #endif
122
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