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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/*
* Generic Backlight Driver
*
* Copyright (c) 2004-2008 Richard Purdie
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/fb.h>
#include <linux/backlight.h>
static int genericbl_intensity;
static struct backlight_device *generic_backlight_device;
static struct generic_bl_info *bl_machinfo;
/* Flag to signal when the battery is low */
#define GENERICBL_BATTLOW BL_CORE_DRIVER1
static int genericbl_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
if (bd->props.power != FB_BLANK_UNBLANK)
intensity = 0;
if (bd->props.state & BL_CORE_FBBLANK)
intensity = 0;
if (bd->props.state & BL_CORE_SUSPENDED)
intensity = 0;
if (bd->props.state & GENERICBL_BATTLOW)
intensity &= bl_machinfo->limit_mask;
bl_machinfo->set_bl_intensity(intensity);
genericbl_intensity = intensity;
if (bl_machinfo->kick_battery)
bl_machinfo->kick_battery();
return 0;
}
static int genericbl_get_intensity(struct backlight_device *bd)
{
return genericbl_intensity;
}
/*
* Called when the battery is low to limit the backlight intensity.
* If limit==0 clear any limit, otherwise limit the intensity
*/
void corgibl_limit_intensity(int limit)
{
struct backlight_device *bd = generic_backlight_device;
mutex_lock(&bd->ops_lock);
if (limit)
bd->props.state |= GENERICBL_BATTLOW;
else
bd->props.state &= ~GENERICBL_BATTLOW;
backlight_update_status(generic_backlight_device);
mutex_unlock(&bd->ops_lock);
}
EXPORT_SYMBOL(corgibl_limit_intensity);
static const struct backlight_ops genericbl_ops = {
.options = BL_CORE_SUSPENDRESUME,
.get_brightness = genericbl_get_intensity,
.update_status = genericbl_send_intensity,
};
static int genericbl_probe(struct platform_device *pdev)
{
struct backlight_properties props;
struct generic_bl_info *machinfo = pdev->dev.platform_data;
const char *name = "generic-bl";
struct backlight_device *bd;
bl_machinfo = machinfo;
if (!machinfo->limit_mask)
machinfo->limit_mask = -1;
if (machinfo->name)
name = machinfo->name;
memset(&props, 0, sizeof(struct backlight_properties));
props.max_brightness = machinfo->max_intensity;
bd = backlight_device_register(name, &pdev->dev, NULL, &genericbl_ops,
&props);
if (IS_ERR (bd))
return PTR_ERR (bd);
platform_set_drvdata(pdev, bd);
bd->props.power = FB_BLANK_UNBLANK;
bd->props.brightness = machinfo->default_intensity;
backlight_update_status(bd);
generic_backlight_device = bd;
printk("Generic Backlight Driver Initialized.\n");
return 0;
}
static int genericbl_remove(struct platform_device *pdev)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
bd->props.power = 0;
bd->props.brightness = 0;
backlight_update_status(bd);
backlight_device_unregister(bd);
printk("Generic Backlight Driver Unloaded\n");
return 0;
}
static struct platform_driver genericbl_driver = {
.probe = genericbl_probe,
.remove = genericbl_remove,
.driver = {
.name = "generic-bl",
},
};
static int __init genericbl_init(void)
{
return platform_driver_register(&genericbl_driver);
}
static void __exit genericbl_exit(void)
{
platform_driver_unregister(&genericbl_driver);
}
module_init(genericbl_init);
module_exit(genericbl_exit);
MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
MODULE_DESCRIPTION("Generic Backlight Driver");
MODULE_LICENSE("GPL");
|
