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
genericbl_send_intensity(struct backlight_device * bd)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
genericbl_get_intensity(struct backlight_device * bd)50 static int genericbl_get_intensity(struct backlight_device *bd)
51 {
52 return genericbl_intensity;
53 }
54
55 static const struct backlight_ops genericbl_ops = {
56 .options = BL_CORE_SUSPENDRESUME,
57 .get_brightness = genericbl_get_intensity,
58 .update_status = genericbl_send_intensity,
59 };
60
genericbl_probe(struct platform_device * pdev)61 static int genericbl_probe(struct platform_device *pdev)
62 {
63 struct backlight_properties props;
64 struct generic_bl_info *machinfo = dev_get_platdata(&pdev->dev);
65 const char *name = "generic-bl";
66 struct backlight_device *bd;
67
68 bl_machinfo = machinfo;
69 if (!machinfo->limit_mask)
70 machinfo->limit_mask = -1;
71
72 if (machinfo->name)
73 name = machinfo->name;
74
75 memset(&props, 0, sizeof(struct backlight_properties));
76 props.type = BACKLIGHT_RAW;
77 props.max_brightness = machinfo->max_intensity;
78 bd = devm_backlight_device_register(&pdev->dev, name, &pdev->dev,
79 NULL, &genericbl_ops, &props);
80 if (IS_ERR(bd))
81 return PTR_ERR(bd);
82
83 platform_set_drvdata(pdev, bd);
84
85 bd->props.power = FB_BLANK_UNBLANK;
86 bd->props.brightness = machinfo->default_intensity;
87 backlight_update_status(bd);
88
89 generic_backlight_device = bd;
90
91 dev_info(&pdev->dev, "Generic Backlight Driver Initialized.\n");
92 return 0;
93 }
94
genericbl_remove(struct platform_device * pdev)95 static int genericbl_remove(struct platform_device *pdev)
96 {
97 struct backlight_device *bd = platform_get_drvdata(pdev);
98
99 bd->props.power = 0;
100 bd->props.brightness = 0;
101 backlight_update_status(bd);
102
103 dev_info(&pdev->dev, "Generic Backlight Driver Unloaded\n");
104 return 0;
105 }
106
107 static struct platform_driver genericbl_driver = {
108 .probe = genericbl_probe,
109 .remove = genericbl_remove,
110 .driver = {
111 .name = "generic-bl",
112 },
113 };
114
115 module_platform_driver(genericbl_driver);
116
117 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
118 MODULE_DESCRIPTION("Generic Backlight Driver");
119 MODULE_LICENSE("GPL");
120