Merge branch 'locks' of git://linux-nfs.org/~bfields/linux
[linux-2.6] / drivers / video / backlight / hp680_bl.c
1 /*
2  *  Backlight Driver for HP Jornada 680
3  *
4  *  Copyright (c) 2005 Andriy Skulysh
5  *
6  *  Based on Sharp's Corgi Backlight Driver
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/platform_device.h>
17 #include <linux/spinlock.h>
18 #include <linux/fb.h>
19 #include <linux/backlight.h>
20
21 #include <asm/cpu/dac.h>
22 #include <asm/hp6xx.h>
23 #include <asm/hd64461.h>
24
25 #define HP680_MAX_INTENSITY 255
26 #define HP680_DEFAULT_INTENSITY 10
27
28 static int hp680bl_suspended;
29 static int current_intensity = 0;
30 static DEFINE_SPINLOCK(bl_lock);
31
32 static void hp680bl_send_intensity(struct backlight_device *bd)
33 {
34         unsigned long flags;
35         u16 v;
36         int intensity = bd->props.brightness;
37
38         if (bd->props.power != FB_BLANK_UNBLANK)
39                 intensity = 0;
40         if (bd->props.fb_blank != FB_BLANK_UNBLANK)
41                 intensity = 0;
42         if (hp680bl_suspended)
43                 intensity = 0;
44
45         spin_lock_irqsave(&bl_lock, flags);
46         if (intensity && current_intensity == 0) {
47                 sh_dac_enable(DAC_LCD_BRIGHTNESS);
48                 v = inw(HD64461_GPBDR);
49                 v &= ~HD64461_GPBDR_LCDOFF;
50                 outw(v, HD64461_GPBDR);
51                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
52         } else if (intensity == 0 && current_intensity != 0) {
53                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
54                 sh_dac_disable(DAC_LCD_BRIGHTNESS);
55                 v = inw(HD64461_GPBDR);
56                 v |= HD64461_GPBDR_LCDOFF;
57                 outw(v, HD64461_GPBDR);
58         } else if (intensity) {
59                 sh_dac_output(255-(u8)intensity, DAC_LCD_BRIGHTNESS);
60         }
61         spin_unlock_irqrestore(&bl_lock, flags);
62
63         current_intensity = intensity;
64 }
65
66
67 #ifdef CONFIG_PM
68 static int hp680bl_suspend(struct platform_device *pdev, pm_message_t state)
69 {
70         struct backlight_device *bd = platform_get_drvdata(pdev);
71
72         hp680bl_suspended = 1;
73         hp680bl_send_intensity(bd);
74         return 0;
75 }
76
77 static int hp680bl_resume(struct platform_device *pdev)
78 {
79         struct backlight_device *bd = platform_get_drvdata(pdev);
80
81         hp680bl_suspended = 0;
82         hp680bl_send_intensity(bd);
83         return 0;
84 }
85 #else
86 #define hp680bl_suspend NULL
87 #define hp680bl_resume  NULL
88 #endif
89
90 static int hp680bl_set_intensity(struct backlight_device *bd)
91 {
92         hp680bl_send_intensity(bd);
93         return 0;
94 }
95
96 static int hp680bl_get_intensity(struct backlight_device *bd)
97 {
98         return current_intensity;
99 }
100
101 static struct backlight_ops hp680bl_ops = {
102         .get_brightness = hp680bl_get_intensity,
103         .update_status  = hp680bl_set_intensity,
104 };
105
106 static int __init hp680bl_probe(struct platform_device *pdev)
107 {
108         struct backlight_device *bd;
109
110         bd = backlight_device_register ("hp680-bl", &pdev->dev, NULL,
111                     &hp680bl_ops);
112         if (IS_ERR(bd))
113                 return PTR_ERR(bd);
114
115         platform_set_drvdata(pdev, bd);
116
117         bd->props.max_brightness = HP680_MAX_INTENSITY;
118         bd->props.brightness = HP680_DEFAULT_INTENSITY;
119         hp680bl_send_intensity(bd);
120
121         return 0;
122 }
123
124 static int hp680bl_remove(struct platform_device *pdev)
125 {
126         struct backlight_device *bd = platform_get_drvdata(pdev);
127
128         bd->props.brightness = 0;
129         bd->props.power = 0;
130         hp680bl_send_intensity(bd);
131
132         backlight_device_unregister(bd);
133
134         return 0;
135 }
136
137 static struct platform_driver hp680bl_driver = {
138         .probe          = hp680bl_probe,
139         .remove         = hp680bl_remove,
140         .suspend        = hp680bl_suspend,
141         .resume         = hp680bl_resume,
142         .driver         = {
143                 .name   = "hp680-bl",
144         },
145 };
146
147 static struct platform_device *hp680bl_device;
148
149 static int __init hp680bl_init(void)
150 {
151         int ret;
152
153         ret = platform_driver_register(&hp680bl_driver);
154         if (!ret) {
155                 hp680bl_device = platform_device_alloc("hp680-bl", -1);
156                 if (!hp680bl_device)
157                         return -ENOMEM;
158
159                 ret = platform_device_add(hp680bl_device);
160
161                 if (ret) {
162                         platform_device_put(hp680bl_device);
163                         platform_driver_unregister(&hp680bl_driver);
164                 }
165         }
166         return ret;
167 }
168
169 static void __exit hp680bl_exit(void)
170 {
171         platform_device_unregister(hp680bl_device);
172         platform_driver_unregister(&hp680bl_driver);
173 }
174
175 module_init(hp680bl_init);
176 module_exit(hp680bl_exit);
177
178 MODULE_AUTHOR("Andriy Skulysh <askulysh@gmail.com>");
179 MODULE_DESCRIPTION("HP Jornada 680 Backlight Driver");
180 MODULE_LICENSE("GPL");