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 
genericbl_send_intensity(struct backlight_device * bd)24 static int genericbl_send_intensity(struct backlight_device *bd)
25 {
26 	int intensity = bd->props.brightness;
27 
28 	if (bd->props.power != FB_BLANK_UNBLANK)
29 		intensity = 0;
30 	if (bd->props.state & BL_CORE_FBBLANK)
31 		intensity = 0;
32 	if (bd->props.state & BL_CORE_SUSPENDED)
33 		intensity = 0;
34 
35 	bl_machinfo->set_bl_intensity(intensity);
36 
37 	genericbl_intensity = intensity;
38 
39 	if (bl_machinfo->kick_battery)
40 		bl_machinfo->kick_battery();
41 
42 	return 0;
43 }
44 
genericbl_get_intensity(struct backlight_device * bd)45 static int genericbl_get_intensity(struct backlight_device *bd)
46 {
47 	return genericbl_intensity;
48 }
49 
50 static const struct backlight_ops genericbl_ops = {
51 	.options = BL_CORE_SUSPENDRESUME,
52 	.get_brightness = genericbl_get_intensity,
53 	.update_status  = genericbl_send_intensity,
54 };
55 
genericbl_probe(struct platform_device * pdev)56 static int genericbl_probe(struct platform_device *pdev)
57 {
58 	struct backlight_properties props;
59 	struct generic_bl_info *machinfo = dev_get_platdata(&pdev->dev);
60 	const char *name = "generic-bl";
61 	struct backlight_device *bd;
62 
63 	bl_machinfo = machinfo;
64 	if (!machinfo->limit_mask)
65 		machinfo->limit_mask = -1;
66 
67 	if (machinfo->name)
68 		name = machinfo->name;
69 
70 	memset(&props, 0, sizeof(struct backlight_properties));
71 	props.type = BACKLIGHT_RAW;
72 	props.max_brightness = machinfo->max_intensity;
73 	bd = devm_backlight_device_register(&pdev->dev, name, &pdev->dev,
74 					NULL, &genericbl_ops, &props);
75 	if (IS_ERR(bd))
76 		return PTR_ERR(bd);
77 
78 	platform_set_drvdata(pdev, bd);
79 
80 	bd->props.power = FB_BLANK_UNBLANK;
81 	bd->props.brightness = machinfo->default_intensity;
82 	backlight_update_status(bd);
83 
84 	generic_backlight_device = bd;
85 
86 	dev_info(&pdev->dev, "Generic Backlight Driver Initialized.\n");
87 	return 0;
88 }
89 
genericbl_remove(struct platform_device * pdev)90 static int genericbl_remove(struct platform_device *pdev)
91 {
92 	struct backlight_device *bd = platform_get_drvdata(pdev);
93 
94 	bd->props.power = 0;
95 	bd->props.brightness = 0;
96 	backlight_update_status(bd);
97 
98 	dev_info(&pdev->dev, "Generic Backlight Driver Unloaded\n");
99 	return 0;
100 }
101 
102 static struct platform_driver genericbl_driver = {
103 	.probe		= genericbl_probe,
104 	.remove		= genericbl_remove,
105 	.driver		= {
106 		.name	= "generic-bl",
107 	},
108 };
109 
110 module_platform_driver(genericbl_driver);
111 
112 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
113 MODULE_DESCRIPTION("Generic Backlight Driver");
114 MODULE_LICENSE("GPL");
115