2 * Backlight Driver for Sharp Corgi
4 * Copyright (c) 2004-2005 Richard Purdie
6 * Based on Sharp's 2.4 Backlight Driver
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.
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/device.h>
18 #include <linux/spinlock.h>
20 #include <linux/backlight.h>
22 #include <asm/arch-pxa/corgi.h>
23 #include <asm/hardware/scoop.h>
25 #define CORGI_MAX_INTENSITY 0x3e
26 #define CORGI_DEFAULT_INTENSITY 0x1f
27 #define CORGI_LIMIT_MASK 0x0b
29 static int corgibl_powermode = FB_BLANK_UNBLANK;
30 static int current_intensity = 0;
31 static int corgibl_limit = 0;
32 static spinlock_t bl_lock = SPIN_LOCK_UNLOCKED;
34 static void corgibl_send_intensity(int intensity)
37 void (*corgi_kick_batt)(void);
39 if (corgibl_powermode != FB_BLANK_UNBLANK) {
43 intensity &= CORGI_LIMIT_MASK;
46 spin_lock_irqsave(&bl_lock, flags);
48 corgibl_mach_set_intensity(intensity);
50 spin_unlock_irqrestore(&bl_lock, flags);
53 static void corgibl_blank(int blank)
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;
66 case FB_BLANK_UNBLANK:
67 if (corgibl_powermode != FB_BLANK_UNBLANK) {
68 corgibl_powermode = blank;
69 corgibl_send_intensity(current_intensity);
76 static int corgibl_suspend(struct device *dev, pm_message_t state, u32 level)
78 if (level == SUSPEND_POWER_DOWN)
79 corgibl_blank(FB_BLANK_POWERDOWN);
83 static int corgibl_resume(struct device *dev, u32 level)
85 if (level == RESUME_POWER_ON)
86 corgibl_blank(FB_BLANK_UNBLANK);
90 #define corgibl_suspend NULL
91 #define corgibl_resume NULL
95 static int corgibl_set_power(struct backlight_device *bd, int state)
101 static int corgibl_get_power(struct backlight_device *bd)
103 return corgibl_powermode;
106 static int corgibl_set_intensity(struct backlight_device *bd, int intensity)
108 if (intensity > corgibl_data.max_brightness)
109 intensity = corgibl_data.max_brightness;
110 corgibl_send_intensity(intensity);
111 current_intensity=intensity;
115 static int corgibl_get_intensity(struct backlight_device *bd)
117 return current_intensity;
121 * Called when the battery is low to limit the backlight intensity.
122 * If limit==0 clear any limit, otherwise limit the intensity
124 void corgibl_limit_intensity(int limit)
126 corgibl_limit = (limit ? 1 : 0);
127 corgibl_send_intensity(current_intensity);
129 EXPORT_SYMBOL(corgibl_limit_intensity);
132 static struct backlight_properties corgibl_data = {
133 .owner = THIS_MODULE,
134 .get_power = corgibl_get_power,
135 .set_power = corgibl_set_power,
136 .get_brightness = corgibl_get_intensity,
137 .set_brightness = corgibl_set_intensity,
140 static struct backlight_device *corgi_backlight_device;
142 static int __init corgibl_probe(struct device *dev)
144 struct corgibl_machinfo *machinfo = dev->platform_data;
146 corgibl_data.max_brightness = machinfo->max_intensity;
147 corgibl_mach_set_intensity = machinfo->set_bl_intensity;
149 corgi_backlight_device = backlight_device_register ("corgi-bl",
150 NULL, &corgibl_data);
151 if (IS_ERR (corgi_backlight_device))
152 return PTR_ERR (corgi_backlight_device);
154 corgibl_set_intensity(NULL, CORGI_DEFAULT_INTENSITY);
155 corgibl_limit_intensity(0);
157 printk("Corgi Backlight Driver Initialized.\n");
161 static int corgibl_remove(struct device *dev)
163 backlight_device_unregister(corgi_backlight_device);
165 corgibl_set_intensity(NULL, 0);
167 printk("Corgi Backlight Driver Unloaded\n");
171 static struct device_driver corgibl_driver = {
173 .bus = &platform_bus_type,
174 .probe = corgibl_probe,
175 .remove = corgibl_remove,
176 .suspend = corgibl_suspend,
177 .resume = corgibl_resume,
180 static int __init corgibl_init(void)
182 return driver_register(&corgibl_driver);
185 static void __exit corgibl_exit(void)
187 driver_unregister(&corgibl_driver);
190 module_init(corgibl_init);
191 module_exit(corgibl_exit);
193 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
194 MODULE_DESCRIPTION("Corgi Backlight Driver");
195 MODULE_LICENSE("GPLv2");