aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/video/backlight/adx_bl.c
blob: 7f4a7c30a98b1f3a09fd020c4c5906f386a1015c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
 * linux/drivers/video/backlight/adx.c
 *
 * Copyright (C) 2009 Avionic Design GmbH
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Written by Thierry Reding <thierry.reding@avionic-design.de>
 */

#include <linux/backlight.h>
#include <linux/fb.h>
#include <linux/gfp.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>

/* register definitions */
#define ADX_BACKLIGHT_CONTROL		0x00
#define ADX_BACKLIGHT_CONTROL_ENABLE	(1 << 0)
#define ADX_BACKLIGHT_BRIGHTNESS	0x08
#define ADX_BACKLIGHT_STATUS		0x10
#define ADX_BACKLIGHT_ERROR		0x18

struct adxbl {
	void __iomem *base;
};

static int adx_backlight_update_status(struct backlight_device *bldev)
{
	struct adxbl *bl = bl_get_data(bldev);
	u32 value;

	value = bldev->props.brightness;
	writel(value, bl->base + ADX_BACKLIGHT_BRIGHTNESS);

	value = readl(bl->base + ADX_BACKLIGHT_CONTROL);

	if (bldev->props.state & BL_CORE_FBBLANK)
		value &= ~ADX_BACKLIGHT_CONTROL_ENABLE;
	else
		value |= ADX_BACKLIGHT_CONTROL_ENABLE;

	writel(value, bl->base + ADX_BACKLIGHT_CONTROL);

	return 0;
}

static int adx_backlight_get_brightness(struct backlight_device *bldev)
{
	struct adxbl *bl = bl_get_data(bldev);
	u32 brightness;

	brightness = readl(bl->base + ADX_BACKLIGHT_BRIGHTNESS);
	return brightness & 0xff;
}

static int adx_backlight_check_fb(struct backlight_device *bldev, struct fb_info *fb)
{
	return 1;
}

static const struct backlight_ops adx_backlight_ops = {
	.options = 0,
	.update_status = adx_backlight_update_status,
	.get_brightness = adx_backlight_get_brightness,
	.check_fb = adx_backlight_check_fb,
};

static int __devinit adx_backlight_probe(struct platform_device *pdev)
{
	struct backlight_properties props;
	struct backlight_device *bldev;
	struct resource *res;
	struct adxbl *bl;
	int ret = 0;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		ret = -ENXIO;
		goto out;
	}

	res = devm_request_mem_region(&pdev->dev, res->start,
			resource_size(res), res->name);
	if (!res) {
		ret = -ENXIO;
		goto out;
	}

	bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
	if (!bl) {
		ret = -ENOMEM;
		goto out;
	}

	bl->base = devm_ioremap_nocache(&pdev->dev, res->start,
			resource_size(res));
	if (!bl->base) {
		ret = -ENXIO;
		goto out;
	}

	memset(&props, 0, sizeof(struct backlight_properties));
	props.max_brightness = 0xff;
	bldev = backlight_device_register(dev_name(&pdev->dev), &pdev->dev,
					  bl, &adx_backlight_ops, &props);
	if (!bldev) {
		ret = -ENOMEM;
		goto out;
	}

	bldev->props.brightness = 0xff;
	bldev->props.power = FB_BLANK_UNBLANK;

	platform_set_drvdata(pdev, bldev);

out:
	return ret;
}

static int __devexit adx_backlight_remove(struct platform_device *pdev)
{
	struct backlight_device *bldev;
	int ret = 0;

	bldev = platform_get_drvdata(pdev);
	bldev->props.power = FB_BLANK_UNBLANK;
	bldev->props.brightness = 0xff;
	backlight_update_status(bldev);
	backlight_device_unregister(bldev);
	platform_set_drvdata(pdev, NULL);

	return ret;
}

#ifdef CONFIG_PM
static int adx_backlight_suspend(struct platform_device *pdev,
		pm_message_t state)
{
	return 0;
}

static int adx_backlight_resume(struct platform_device *pdev)
{
	return 0;
}
#else
#define adx_backlight_suspend NULL
#define adx_backlight_resume NULL
#endif

static struct platform_driver adx_backlight_driver = {
	.probe = adx_backlight_probe,
	.remove = __devexit_p(adx_backlight_remove),
	.suspend = adx_backlight_suspend,
	.resume = adx_backlight_resume,
	.driver = {
		.name = "adx-backlight",
		.owner = THIS_MODULE,
	},
};

static int __init adx_backlight_init(void)
{
	return platform_driver_register(&adx_backlight_driver);
}

static void __exit adx_backlight_exit(void)
{
	platform_driver_unregister(&adx_backlight_driver);
}

module_init(adx_backlight_init);
module_exit(adx_backlight_exit);

MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
MODULE_DESCRIPTION("Avionic Design Xanthos Backlight Driver");
MODULE_LICENSE("GPL v2");