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[~shefty/rdma-dev.git] / drivers / video / backlight / adx_bl.c
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
27 struct adxbl {
28         void __iomem *base;
29 };
30
31 static 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
51 static 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
60 static int adx_backlight_check_fb(struct backlight_device *bldev, struct fb_info *fb)
61 {
62         return 1;
63 }
64
65 static 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
72 static 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
121 out:
122         return ret;
123 }
124
125 static 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
141 static int adx_backlight_suspend(struct platform_device *pdev,
142                 pm_message_t state)
143 {
144         return 0;
145 }
146
147 static 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
156 static 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
167 static int __init adx_backlight_init(void)
168 {
169         return platform_driver_register(&adx_backlight_driver);
170 }
171
172 static void __exit adx_backlight_exit(void)
173 {
174         platform_driver_unregister(&adx_backlight_driver);
175 }
176
177 module_init(adx_backlight_init);
178 module_exit(adx_backlight_exit);
179
180 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
181 MODULE_DESCRIPTION("Avionic Design Xanthos Backlight Driver");
182 MODULE_LICENSE("GPL v2");