4867498f68e8e0b073157e472ce033e725251b60
[linux-2.6.git] / drivers / video / backlight / corgi_bl.c
1 /*
2  *  Backlight Driver for Sharp Corgi
3  *
4  *  Copyright (c) 2004-2005 Richard Purdie
5  *
6  *  Based on Sharp's 2.4 Backlight Driver
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License version 2 as
10  *  published by the Free Software Foundation.
11  *
12  */
13
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/platform_device.h>
18 #include <linux/spinlock.h>
19 #include <linux/fb.h>
20 #include <linux/backlight.h>
21
22 #include <asm/arch/sharpsl.h>
23
24 #define CORGI_DEFAULT_INTENSITY         0x1f
25 #define CORGI_LIMIT_MASK                0x0b
26
27 static int corgibl_powermode = FB_BLANK_UNBLANK;
28 static int current_intensity = 0;
29 static int corgibl_limit = 0;
30 static void (*corgibl_mach_set_intensity)(int intensity);
31 static spinlock_t bl_lock = SPIN_LOCK_UNLOCKED;
32 static struct backlight_properties corgibl_data;
33
34 static void corgibl_send_intensity(int intensity)
35 {
36         unsigned long flags;
37         void (*corgi_kick_batt)(void);
38
39         if (corgibl_powermode != FB_BLANK_UNBLANK) {
40                 intensity = 0;
41         } else {
42                 if (corgibl_limit)
43                         intensity &= CORGI_LIMIT_MASK;
44         }
45
46         spin_lock_irqsave(&bl_lock, flags);
47
48         corgibl_mach_set_intensity(intensity);
49
50         spin_unlock_irqrestore(&bl_lock, flags);
51 }
52
53 static void corgibl_blank(int blank)
54 {
55         switch(blank) {
56
57         case FB_BLANK_NORMAL:
58         case FB_BLANK_VSYNC_SUSPEND:
59         case FB_BLANK_HSYNC_SUSPEND:
60         case FB_BLANK_POWERDOWN:
61                 if (corgibl_powermode == FB_BLANK_UNBLANK) {
62                         corgibl_send_intensity(0);
63                         corgibl_powermode = blank;
64                 }
65                 break;
66         case FB_BLANK_UNBLANK:
67                 if (corgibl_powermode != FB_BLANK_UNBLANK) {
68                         corgibl_powermode = blank;
69                         corgibl_send_intensity(current_intensity);
70                 }
71                 break;
72         }
73 }
74
75 #ifdef CONFIG_PM
76 static int corgibl_suspend(struct device *dev, pm_message_t state)
77 {
78         corgibl_blank(FB_BLANK_POWERDOWN);
79         return 0;
80 }
81
82 static int corgibl_resume(struct device *dev)
83 {
84         corgibl_blank(FB_BLANK_UNBLANK);
85         return 0;
86 }
87 #else
88 #define corgibl_suspend NULL
89 #define corgibl_resume  NULL
90 #endif
91
92
93 static int corgibl_set_power(struct backlight_device *bd, int state)
94 {
95         corgibl_blank(state);
96         return 0;
97 }
98
99 static int corgibl_get_power(struct backlight_device *bd)
100 {
101         return corgibl_powermode;
102 }
103
104 static int corgibl_set_intensity(struct backlight_device *bd, int intensity)
105 {
106         if (intensity > corgibl_data.max_brightness)
107                 intensity = corgibl_data.max_brightness;
108         corgibl_send_intensity(intensity);
109         current_intensity=intensity;
110         return 0;
111 }
112
113 static int corgibl_get_intensity(struct backlight_device *bd)
114 {
115         return current_intensity;
116 }
117
118 /*
119  * Called when the battery is low to limit the backlight intensity.
120  * If limit==0 clear any limit, otherwise limit the intensity
121  */
122 void corgibl_limit_intensity(int limit)
123 {
124         corgibl_limit = (limit ? 1 : 0);
125         corgibl_send_intensity(current_intensity);
126 }
127 EXPORT_SYMBOL(corgibl_limit_intensity);
128
129
130 static struct backlight_properties corgibl_data = {
131         .owner          = THIS_MODULE,
132         .get_power      = corgibl_get_power,
133         .set_power      = corgibl_set_power,
134         .get_brightness = corgibl_get_intensity,
135         .set_brightness = corgibl_set_intensity,
136 };
137
138 static struct backlight_device *corgi_backlight_device;
139
140 static int __init corgibl_probe(struct device *dev)
141 {
142         struct corgibl_machinfo *machinfo = dev->platform_data;
143
144         corgibl_data.max_brightness = machinfo->max_intensity;
145         corgibl_mach_set_intensity = machinfo->set_bl_intensity;
146
147         corgi_backlight_device = backlight_device_register ("corgi-bl",
148                 NULL, &corgibl_data);
149         if (IS_ERR (corgi_backlight_device))
150                 return PTR_ERR (corgi_backlight_device);
151
152         corgibl_set_intensity(NULL, CORGI_DEFAULT_INTENSITY);
153         corgibl_limit_intensity(0);
154
155         printk("Corgi Backlight Driver Initialized.\n");
156         return 0;
157 }
158
159 static int corgibl_remove(struct device *dev)
160 {
161         backlight_device_unregister(corgi_backlight_device);
162
163         corgibl_set_intensity(NULL, 0);
164
165         printk("Corgi Backlight Driver Unloaded\n");
166         return 0;
167 }
168
169 static struct device_driver corgibl_driver = {
170         .name           = "corgi-bl",
171         .bus            = &platform_bus_type,
172         .probe          = corgibl_probe,
173         .remove         = corgibl_remove,
174         .suspend        = corgibl_suspend,
175         .resume         = corgibl_resume,
176 };
177
178 static int __init corgibl_init(void)
179 {
180         return driver_register(&corgibl_driver);
181 }
182
183 static void __exit corgibl_exit(void)
184 {
185         driver_unregister(&corgibl_driver);
186 }
187
188 module_init(corgibl_init);
189 module_exit(corgibl_exit);
190
191 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
192 MODULE_DESCRIPTION("Corgi Backlight Driver");
193 MODULE_LICENSE("GPLv2");