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
20static int genericbl_intensity;
21static struct backlight_device *generic_backlight_device;
22static struct generic_bl_info *bl_machinfo;
23
24/* Flag to signal when the battery is low */
25#define GENERICBL_BATTLOW       BL_CORE_DRIVER1
26
27static 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
50static int genericbl_get_intensity(struct backlight_device *bd)
51{
52	return genericbl_intensity;
53}
54
55static 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
61static 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
95static 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
107static struct platform_driver genericbl_driver = {
108	.probe		= genericbl_probe,
109	.remove		= genericbl_remove,
110	.driver		= {
111		.name	= "generic-bl",
112	},
113};
114
115module_platform_driver(genericbl_driver);
116
117MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
118MODULE_DESCRIPTION("Generic Backlight Driver");
119MODULE_LICENSE("GPL");
120