tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * linux/drivers/video/backlight/adx.c
3 *
4 * Copyright (C) 2009 Avionic Design GmbH
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 * Written by Thierry Reding <thierry.reding@avionic-design.de>
11 */
12
13#include <linux/backlight.h>
14#include <linux/fb.h>
15#include <linux/gfp.h>
16#include <linux/io.h>
17#include <linux/module.h>
18#include <linux/platform_device.h>
19
20/* register definitions */
21#define ADX_BACKLIGHT_CONTROL 0x00
22#define ADX_BACKLIGHT_CONTROL_ENABLE (1 << 0)
23#define ADX_BACKLIGHT_BRIGHTNESS 0x08
24#define ADX_BACKLIGHT_STATUS 0x10
25#define ADX_BACKLIGHT_ERROR 0x18
26
27struct adxbl {
28 void __iomem *base;
29};
30
31static int adx_backlight_update_status(struct backlight_device *bldev)
32{
33 struct adxbl *bl = bl_get_data(bldev);
34 u32 value;
35
36 value = bldev->props.brightness;
37 writel(value, bl->base + ADX_BACKLIGHT_BRIGHTNESS);
38
39 value = readl(bl->base + ADX_BACKLIGHT_CONTROL);
40
41 if (bldev->props.state & BL_CORE_FBBLANK)
42 value &= ~ADX_BACKLIGHT_CONTROL_ENABLE;
43 else
44 value |= ADX_BACKLIGHT_CONTROL_ENABLE;
45
46 writel(value, bl->base + ADX_BACKLIGHT_CONTROL);
47
48 return 0;
49}
50
51static int adx_backlight_get_brightness(struct backlight_device *bldev)
52{
53 struct adxbl *bl = bl_get_data(bldev);
54 u32 brightness;
55
56 brightness = readl(bl->base + ADX_BACKLIGHT_BRIGHTNESS);
57 return brightness & 0xff;
58}
59
60static int adx_backlight_check_fb(struct backlight_device *bldev, struct fb_info *fb)
61{
62 return 1;
63}
64
65static const struct backlight_ops adx_backlight_ops = {
66 .options = 0,
67 .update_status = adx_backlight_update_status,
68 .get_brightness = adx_backlight_get_brightness,
69 .check_fb = adx_backlight_check_fb,
70};
71
72static int __devinit adx_backlight_probe(struct platform_device *pdev)
73{
74 struct backlight_properties props;
75 struct backlight_device *bldev;
76 struct resource *res;
77 struct adxbl *bl;
78 int ret = 0;
79
80 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
81 if (!res) {
82 ret = -ENXIO;
83 goto out;
84 }
85
86 res = devm_request_mem_region(&pdev->dev, res->start,
87 resource_size(res), res->name);
88 if (!res) {
89 ret = -ENXIO;
90 goto out;
91 }
92
93 bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
94 if (!bl) {
95 ret = -ENOMEM;
96 goto out;
97 }
98
99 bl->base = devm_ioremap_nocache(&pdev->dev, res->start,
100 resource_size(res));
101 if (!bl->base) {
102 ret = -ENXIO;
103 goto out;
104 }
105
106 memset(&props, 0, sizeof(struct backlight_properties));
107 props.type = BACKLIGHT_RAW;
108 props.max_brightness = 0xff;
109 bldev = backlight_device_register(dev_name(&pdev->dev), &pdev->dev,
110 bl, &adx_backlight_ops, &props);
111 if (IS_ERR(bldev)) {
112 ret = PTR_ERR(bldev);
113 goto out;
114 }
115
116 bldev->props.brightness = 0xff;
117 bldev->props.power = FB_BLANK_UNBLANK;
118
119 platform_set_drvdata(pdev, bldev);
120
121out:
122 return ret;
123}
124
125static int __devexit adx_backlight_remove(struct platform_device *pdev)
126{
127 struct backlight_device *bldev;
128 int ret = 0;
129
130 bldev = platform_get_drvdata(pdev);
131 bldev->props.power = FB_BLANK_UNBLANK;
132 bldev->props.brightness = 0xff;
133 backlight_update_status(bldev);
134 backlight_device_unregister(bldev);
135 platform_set_drvdata(pdev, NULL);
136
137 return ret;
138}
139
140#ifdef CONFIG_PM
141static int adx_backlight_suspend(struct platform_device *pdev,
142 pm_message_t state)
143{
144 return 0;
145}
146
147static int adx_backlight_resume(struct platform_device *pdev)
148{
149 return 0;
150}
151#else
152#define adx_backlight_suspend NULL
153#define adx_backlight_resume NULL
154#endif
155
156static struct platform_driver adx_backlight_driver = {
157 .probe = adx_backlight_probe,
158 .remove = __devexit_p(adx_backlight_remove),
159 .suspend = adx_backlight_suspend,
160 .resume = adx_backlight_resume,
161 .driver = {
162 .name = "adx-backlight",
163 .owner = THIS_MODULE,
164 },
165};
166
167static int __init adx_backlight_init(void)
168{
169 return platform_driver_register(&adx_backlight_driver);
170}
171
172static void __exit adx_backlight_exit(void)
173{
174 platform_driver_unregister(&adx_backlight_driver);
175}
176
177module_init(adx_backlight_init);
178module_exit(adx_backlight_exit);
179
180MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
181MODULE_DESCRIPTION("Avionic Design Xanthos Backlight Driver");
182MODULE_LICENSE("GPL v2");