Merge branch 'sh/stable-updates'
[linux-2.6] / drivers / video / backlight / da903x_bl.c
1 /*
2  * Backlight driver for Dialog Semiconductor DA9030/DA9034
3  *
4  * Copyright (C) 2008 Compulab, Ltd.
5  *      Mike Rapoport <mike@compulab.co.il>
6  *
7  * Copyright (C) 2006-2008 Marvell International Ltd.
8  *      Eric Miao <eric.miao@marvell.com>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/platform_device.h>
18 #include <linux/fb.h>
19 #include <linux/backlight.h>
20 #include <linux/mfd/da903x.h>
21
22 #define DA9030_WLED_CONTROL     0x25
23 #define DA9030_WLED_CP_EN       (1 << 6)
24 #define DA9030_WLED_TRIM(x)     ((x) & 0x7)
25
26 #define DA9034_WLED_CONTROL1    0x3C
27 #define DA9034_WLED_CONTROL2    0x3D
28
29 #define DA9034_WLED_BOOST_EN    (1 << 5)
30
31 #define DA9030_MAX_BRIGHTNESS   7
32 #define DA9034_MAX_BRIGHTNESS   0x7f
33
34 struct da903x_backlight_data {
35         struct device *da903x_dev;
36         int id;
37         int current_brightness;
38 };
39
40 static int da903x_backlight_set(struct backlight_device *bl, int brightness)
41 {
42         struct da903x_backlight_data *data = bl_get_data(bl);
43         struct device *dev = data->da903x_dev;
44         uint8_t val;
45         int ret = 0;
46
47         switch (data->id) {
48         case DA9034_ID_WLED:
49                 ret = da903x_update(dev, DA9034_WLED_CONTROL1,
50                                 brightness, 0x7f);
51                 if (ret)
52                         return ret;
53
54                 if (data->current_brightness && brightness == 0)
55                         ret = da903x_clr_bits(dev,
56                                         DA9034_WLED_CONTROL2,
57                                         DA9034_WLED_BOOST_EN);
58
59                 if (data->current_brightness == 0 && brightness)
60                         ret = da903x_set_bits(dev,
61                                         DA9034_WLED_CONTROL2,
62                                         DA9034_WLED_BOOST_EN);
63                 break;
64         case DA9030_ID_WLED:
65                 val = DA9030_WLED_TRIM(brightness);
66                 val |= brightness ? DA9030_WLED_CP_EN : 0;
67                 ret = da903x_write(dev, DA9030_WLED_CONTROL, val);
68                 break;
69         }
70
71         if (ret)
72                 return ret;
73
74         data->current_brightness = brightness;
75         return 0;
76 }
77
78 static int da903x_backlight_update_status(struct backlight_device *bl)
79 {
80         int brightness = bl->props.brightness;
81
82         if (bl->props.power != FB_BLANK_UNBLANK)
83                 brightness = 0;
84
85         if (bl->props.fb_blank != FB_BLANK_UNBLANK)
86                 brightness = 0;
87
88         return da903x_backlight_set(bl, brightness);
89 }
90
91 static int da903x_backlight_get_brightness(struct backlight_device *bl)
92 {
93         struct da903x_backlight_data *data = bl_get_data(bl);
94         return data->current_brightness;
95 }
96
97 static struct backlight_ops da903x_backlight_ops = {
98         .update_status  = da903x_backlight_update_status,
99         .get_brightness = da903x_backlight_get_brightness,
100 };
101
102 static int da903x_backlight_probe(struct platform_device *pdev)
103 {
104         struct da903x_backlight_data *data;
105         struct backlight_device *bl;
106         int max_brightness;
107
108         data = kzalloc(sizeof(*data), GFP_KERNEL);
109         if (data == NULL)
110                 return -ENOMEM;
111
112         switch (pdev->id) {
113         case DA9030_ID_WLED:
114                 max_brightness = DA9030_MAX_BRIGHTNESS;
115                 break;
116         case DA9034_ID_WLED:
117                 max_brightness = DA9034_MAX_BRIGHTNESS;
118                 break;
119         default:
120                 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n",
121                                 pdev->id);
122                 kfree(data);
123                 return -EINVAL;
124         }
125
126         data->id = pdev->id;
127         data->da903x_dev = pdev->dev.parent;
128         data->current_brightness = 0;
129
130         bl = backlight_device_register(pdev->name, data->da903x_dev,
131                         data, &da903x_backlight_ops);
132         if (IS_ERR(bl)) {
133                 dev_err(&pdev->dev, "failed to register backlight\n");
134                 kfree(data);
135                 return PTR_ERR(bl);
136         }
137
138         bl->props.max_brightness = max_brightness;
139         bl->props.brightness = max_brightness;
140
141         platform_set_drvdata(pdev, bl);
142         backlight_update_status(bl);
143         return 0;
144 }
145
146 static int da903x_backlight_remove(struct platform_device *pdev)
147 {
148         struct backlight_device *bl = platform_get_drvdata(pdev);
149         struct da903x_backlight_data *data = bl_get_data(bl);
150
151         backlight_device_unregister(bl);
152         kfree(data);
153         return 0;
154 }
155
156 #ifdef CONFIG_PM
157 static int da903x_backlight_suspend(struct platform_device *pdev,
158                                  pm_message_t state)
159 {
160         struct backlight_device *bl = platform_get_drvdata(pdev);
161         return da903x_backlight_set(bl, 0);
162 }
163
164 static int da903x_backlight_resume(struct platform_device *pdev)
165 {
166         struct backlight_device *bl = platform_get_drvdata(pdev);
167
168         backlight_update_status(bl);
169         return 0;
170 }
171 #else
172 #define da903x_backlight_suspend        NULL
173 #define da903x_backlight_resume         NULL
174 #endif
175
176 static struct platform_driver da903x_backlight_driver = {
177         .driver         = {
178                 .name   = "da903x-backlight",
179                 .owner  = THIS_MODULE,
180         },
181         .probe          = da903x_backlight_probe,
182         .remove         = da903x_backlight_remove,
183         .suspend        = da903x_backlight_suspend,
184         .resume         = da903x_backlight_resume,
185 };
186
187 static int __init da903x_backlight_init(void)
188 {
189         return platform_driver_register(&da903x_backlight_driver);
190 }
191 module_init(da903x_backlight_init);
192
193 static void __exit da903x_backlight_exit(void)
194 {
195         platform_driver_unregister(&da903x_backlight_driver);
196 }
197 module_exit(da903x_backlight_exit);
198
199 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034");
200 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"
201               "Mike Rapoport <mike@compulab.co.il>");
202 MODULE_LICENSE("GPL");
203 MODULE_ALIAS("platform:da903x-backlight");