blob: 2c3bdfc620b74a0d92cdc0a7bfd5b932b347c682 [file] [log] [blame]
Thierry Reding3b96ea92009-08-14 15:58:56 +02001/*
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/io.h>
16#include <linux/module.h>
17#include <linux/platform_device.h>
18
19/* register definitions */
20#define ADX_BACKLIGHT_CONTROL 0x00
21#define ADX_BACKLIGHT_CONTROL_ENABLE (1 << 0)
22#define ADX_BACKLIGHT_BRIGHTNESS 0x08
23#define ADX_BACKLIGHT_STATUS 0x10
24#define ADX_BACKLIGHT_ERROR 0x18
25
26struct adxbl {
27 void __iomem *base;
28};
29
30static int adx_backlight_update_status(struct backlight_device *bldev)
31{
32 struct adxbl *bl = bl_get_data(bldev);
33 u32 value;
34
35 value = bldev->props.brightness;
36 writel(value, bl->base + ADX_BACKLIGHT_BRIGHTNESS);
37
38 value = readl(bl->base + ADX_BACKLIGHT_CONTROL);
39
40 if (bldev->props.state & BL_CORE_FBBLANK)
41 value &= ~ADX_BACKLIGHT_CONTROL_ENABLE;
42 else
43 value |= ADX_BACKLIGHT_CONTROL_ENABLE;
44
45 writel(value, bl->base + ADX_BACKLIGHT_CONTROL);
46
47 return 0;
48}
49
50static int adx_backlight_get_brightness(struct backlight_device *bldev)
51{
52 struct adxbl *bl = bl_get_data(bldev);
53 u32 brightness;
54
55 brightness = readl(bl->base + ADX_BACKLIGHT_BRIGHTNESS);
56 return brightness & 0xff;
57}
58
59static int adx_backlight_check_fb(struct fb_info *fb)
60{
61 return 1;
62}
63
64static struct backlight_ops adx_backlight_ops = {
65 .options = 0,
66 .update_status = adx_backlight_update_status,
67 .get_brightness = adx_backlight_get_brightness,
68 .check_fb = adx_backlight_check_fb,
69};
70
71static int __devinit adx_backlight_probe(struct platform_device *pdev)
72{
73 struct backlight_device *bldev;
74 struct resource *res;
75 struct adxbl *bl;
76 int ret = 0;
77
78 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
79 if (!res) {
80 ret = -ENXIO;
81 goto out;
82 }
83
84 res = devm_request_mem_region(&pdev->dev, res->start,
85 resource_size(res), res->name);
86 if (!res) {
87 ret = -ENXIO;
88 goto out;
89 }
90
91 bl = devm_kzalloc(&pdev->dev, sizeof(*bl), GFP_KERNEL);
92 if (!bl) {
93 ret = -ENOMEM;
94 goto out;
95 }
96
97 bl->base = devm_ioremap_nocache(&pdev->dev, res->start,
98 resource_size(res));
99 if (!bl->base) {
100 ret = -ENXIO;
101 goto out;
102 }
103
104 bldev = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, bl,
105 &adx_backlight_ops);
106 if (!bldev) {
107 ret = -ENOMEM;
108 goto out;
109 }
110
111 bldev->props.max_brightness = 0xff;
112 bldev->props.brightness = 0xff;
113 bldev->props.power = FB_BLANK_UNBLANK;
114
115 platform_set_drvdata(pdev, bldev);
116
117out:
118 return ret;
119}
120
121static int __devexit adx_backlight_remove(struct platform_device *pdev)
122{
123 struct backlight_device *bldev;
124 int ret = 0;
125
126 bldev = platform_get_drvdata(pdev);
127 bldev->props.power = FB_BLANK_UNBLANK;
128 bldev->props.brightness = 0xff;
129 backlight_update_status(bldev);
130 backlight_device_unregister(bldev);
131 platform_set_drvdata(pdev, NULL);
132
133 return ret;
134}
135
136#ifdef CONFIG_PM
137static int adx_backlight_suspend(struct platform_device *pdev,
138 pm_message_t state)
139{
140 return 0;
141}
142
143static int adx_backlight_resume(struct platform_device *pdev)
144{
145 return 0;
146}
147#else
148#define adx_backlight_suspend NULL
149#define adx_backlight_resume NULL
150#endif
151
152static struct platform_driver adx_backlight_driver = {
153 .probe = adx_backlight_probe,
154 .remove = __devexit_p(adx_backlight_remove),
155 .suspend = adx_backlight_suspend,
156 .resume = adx_backlight_resume,
157 .driver = {
158 .name = "adx-backlight",
159 .owner = THIS_MODULE,
160 },
161};
162
163static int __init adx_backlight_init(void)
164{
165 return platform_driver_register(&adx_backlight_driver);
166}
167
168static void __exit adx_backlight_exit(void)
169{
170 platform_driver_unregister(&adx_backlight_driver);
171}
172
173module_init(adx_backlight_init);
174module_exit(adx_backlight_exit);
175
176MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
177MODULE_DESCRIPTION("Avionic Design Xanthos Backlight Driver");
178MODULE_LICENSE("GPL v2");