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d00ba726 RP |
1 | /* |
2 | * Generic Backlight Driver | |
3 | * | |
4 | * Copyright (c) 2004-2008 Richard Purdie | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | */ | |
11 | ||
8c7610f3 JH |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
d00ba726 RP |
14 | #include <linux/module.h> |
15 | #include <linux/kernel.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/mutex.h> | |
19 | #include <linux/fb.h> | |
20 | #include <linux/backlight.h> | |
21 | ||
22 | static int genericbl_intensity; | |
23 | static struct backlight_device *generic_backlight_device; | |
24 | static struct generic_bl_info *bl_machinfo; | |
25 | ||
26 | /* Flag to signal when the battery is low */ | |
27 | #define GENERICBL_BATTLOW BL_CORE_DRIVER1 | |
28 | ||
29 | static int genericbl_send_intensity(struct backlight_device *bd) | |
30 | { | |
31 | int intensity = bd->props.brightness; | |
32 | ||
33 | if (bd->props.power != FB_BLANK_UNBLANK) | |
34 | intensity = 0; | |
35 | if (bd->props.state & BL_CORE_FBBLANK) | |
36 | intensity = 0; | |
37 | if (bd->props.state & BL_CORE_SUSPENDED) | |
38 | intensity = 0; | |
39 | if (bd->props.state & GENERICBL_BATTLOW) | |
40 | intensity &= bl_machinfo->limit_mask; | |
41 | ||
42 | bl_machinfo->set_bl_intensity(intensity); | |
43 | ||
44 | genericbl_intensity = intensity; | |
45 | ||
46 | if (bl_machinfo->kick_battery) | |
47 | bl_machinfo->kick_battery(); | |
48 | ||
49 | return 0; | |
50 | } | |
51 | ||
52 | static int genericbl_get_intensity(struct backlight_device *bd) | |
53 | { | |
54 | return genericbl_intensity; | |
55 | } | |
56 | ||
57 | /* | |
58 | * Called when the battery is low to limit the backlight intensity. | |
59 | * If limit==0 clear any limit, otherwise limit the intensity | |
60 | */ | |
1bff3a20 | 61 | void genericbl_limit_intensity(int limit) |
d00ba726 RP |
62 | { |
63 | struct backlight_device *bd = generic_backlight_device; | |
64 | ||
65 | mutex_lock(&bd->ops_lock); | |
66 | if (limit) | |
67 | bd->props.state |= GENERICBL_BATTLOW; | |
68 | else | |
69 | bd->props.state &= ~GENERICBL_BATTLOW; | |
70 | backlight_update_status(generic_backlight_device); | |
71 | mutex_unlock(&bd->ops_lock); | |
72 | } | |
1bff3a20 | 73 | EXPORT_SYMBOL(genericbl_limit_intensity); |
d00ba726 | 74 | |
9905a43b | 75 | static const struct backlight_ops genericbl_ops = { |
d00ba726 RP |
76 | .options = BL_CORE_SUSPENDRESUME, |
77 | .get_brightness = genericbl_get_intensity, | |
78 | .update_status = genericbl_send_intensity, | |
79 | }; | |
80 | ||
81 | static int genericbl_probe(struct platform_device *pdev) | |
82 | { | |
a19a6ee6 | 83 | struct backlight_properties props; |
d00ba726 RP |
84 | struct generic_bl_info *machinfo = pdev->dev.platform_data; |
85 | const char *name = "generic-bl"; | |
86 | struct backlight_device *bd; | |
87 | ||
88 | bl_machinfo = machinfo; | |
89 | if (!machinfo->limit_mask) | |
90 | machinfo->limit_mask = -1; | |
91 | ||
92 | if (machinfo->name) | |
93 | name = machinfo->name; | |
94 | ||
a19a6ee6 | 95 | memset(&props, 0, sizeof(struct backlight_properties)); |
bb7ca747 | 96 | props.type = BACKLIGHT_RAW; |
a19a6ee6 MG |
97 | props.max_brightness = machinfo->max_intensity; |
98 | bd = backlight_device_register(name, &pdev->dev, NULL, &genericbl_ops, | |
99 | &props); | |
d00ba726 RP |
100 | if (IS_ERR (bd)) |
101 | return PTR_ERR (bd); | |
102 | ||
103 | platform_set_drvdata(pdev, bd); | |
104 | ||
d00ba726 RP |
105 | bd->props.power = FB_BLANK_UNBLANK; |
106 | bd->props.brightness = machinfo->default_intensity; | |
107 | backlight_update_status(bd); | |
108 | ||
109 | generic_backlight_device = bd; | |
110 | ||
8c7610f3 | 111 | pr_info("Generic Backlight Driver Initialized.\n"); |
d00ba726 RP |
112 | return 0; |
113 | } | |
114 | ||
115 | static int genericbl_remove(struct platform_device *pdev) | |
116 | { | |
117 | struct backlight_device *bd = platform_get_drvdata(pdev); | |
118 | ||
119 | bd->props.power = 0; | |
120 | bd->props.brightness = 0; | |
121 | backlight_update_status(bd); | |
122 | ||
123 | backlight_device_unregister(bd); | |
124 | ||
8c7610f3 | 125 | pr_info("Generic Backlight Driver Unloaded\n"); |
d00ba726 RP |
126 | return 0; |
127 | } | |
128 | ||
129 | static struct platform_driver genericbl_driver = { | |
130 | .probe = genericbl_probe, | |
131 | .remove = genericbl_remove, | |
132 | .driver = { | |
133 | .name = "generic-bl", | |
134 | }, | |
135 | }; | |
136 | ||
81178e02 | 137 | module_platform_driver(genericbl_driver); |
d00ba726 RP |
138 | |
139 | MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>"); | |
140 | MODULE_DESCRIPTION("Generic Backlight Driver"); | |
141 | MODULE_LICENSE("GPL"); |