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