linux/drivers/video/backlight/corgi_bl.c

199 lines
4.5 KiB
C

/*
* Backlight Driver for Sharp Corgi
*
* Copyright (c) 2004-2005 Richard Purdie
*
* Based on Sharp's 2.4 Backlight Driver
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <asm/arch-pxa/corgi.h>
#include <asm/hardware/scoop.h>
#define CORGI_MAX_INTENSITY 0x3e
#define CORGI_DEFAULT_INTENSITY 0x1f
#define CORGI_LIMIT_MASK 0x0b
static int corgibl_powermode = FB_BLANK_UNBLANK;
static int current_intensity = 0;
static int corgibl_limit = 0;
static spinlock_t bl_lock = SPIN_LOCK_UNLOCKED;
static void corgibl_send_intensity(int intensity)
{
unsigned long flags;
void (*corgi_kick_batt)(void);
if (corgibl_powermode != FB_BLANK_UNBLANK) {
intensity = 0;
} else {
if (corgibl_limit)
intensity &= CORGI_LIMIT_MASK;
}
/* Skip 0x20 as it will blank the display */
if (intensity >= 0x20)
intensity++;
spin_lock_irqsave(&bl_lock, flags);
/* Bits 0-4 are accessed via the SSP interface */
corgi_ssp_blduty_set(intensity & 0x1f);
/* Bit 5 is via SCOOP */
if (intensity & 0x0020)
set_scoop_gpio(&corgiscoop_device.dev, CORGI_SCP_BACKLIGHT_CONT);
else
reset_scoop_gpio(&corgiscoop_device.dev, CORGI_SCP_BACKLIGHT_CONT);
spin_unlock_irqrestore(&bl_lock, flags);
}
static void corgibl_blank(int blank)
{
switch(blank) {
case FB_BLANK_NORMAL:
case FB_BLANK_VSYNC_SUSPEND:
case FB_BLANK_HSYNC_SUSPEND:
case FB_BLANK_POWERDOWN:
if (corgibl_powermode == FB_BLANK_UNBLANK) {
corgibl_send_intensity(0);
corgibl_powermode = blank;
}
break;
case FB_BLANK_UNBLANK:
if (corgibl_powermode != FB_BLANK_UNBLANK) {
corgibl_powermode = blank;
corgibl_send_intensity(current_intensity);
}
break;
}
}
#ifdef CONFIG_PM
static int corgibl_suspend(struct device *dev, pm_message_t state, u32 level)
{
if (level == SUSPEND_POWER_DOWN)
corgibl_blank(FB_BLANK_POWERDOWN);
return 0;
}
static int corgibl_resume(struct device *dev, u32 level)
{
if (level == RESUME_POWER_ON)
corgibl_blank(FB_BLANK_UNBLANK);
return 0;
}
#else
#define corgibl_suspend NULL
#define corgibl_resume NULL
#endif
static int corgibl_set_power(struct backlight_device *bd, int state)
{
corgibl_blank(state);
return 0;
}
static int corgibl_get_power(struct backlight_device *bd)
{
return corgibl_powermode;
}
static int corgibl_set_intensity(struct backlight_device *bd, int intensity)
{
if (intensity > CORGI_MAX_INTENSITY)
intensity = CORGI_MAX_INTENSITY;
corgibl_send_intensity(intensity);
current_intensity=intensity;
return 0;
}
static int corgibl_get_intensity(struct backlight_device *bd)
{
return current_intensity;
}
/*
* Called when the battery is low to limit the backlight intensity.
* If limit==0 clear any limit, otherwise limit the intensity
*/
void corgibl_limit_intensity(int limit)
{
corgibl_limit = (limit ? 1 : 0);
corgibl_send_intensity(current_intensity);
}
EXPORT_SYMBOL(corgibl_limit_intensity);
static struct backlight_properties corgibl_data = {
.owner = THIS_MODULE,
.get_power = corgibl_get_power,
.set_power = corgibl_set_power,
.max_brightness = CORGI_MAX_INTENSITY,
.get_brightness = corgibl_get_intensity,
.set_brightness = corgibl_set_intensity,
};
static struct backlight_device *corgi_backlight_device;
static int __init corgibl_probe(struct device *dev)
{
corgi_backlight_device = backlight_device_register ("corgi-bl",
NULL, &corgibl_data);
if (IS_ERR (corgi_backlight_device))
return PTR_ERR (corgi_backlight_device);
corgibl_set_intensity(NULL, CORGI_DEFAULT_INTENSITY);
printk("Corgi Backlight Driver Initialized.\n");
return 0;
}
static int corgibl_remove(struct device *dev)
{
backlight_device_unregister(corgi_backlight_device);
corgibl_set_intensity(NULL, 0);
printk("Corgi Backlight Driver Unloaded\n");
return 0;
}
static struct device_driver corgibl_driver = {
.name = "corgi-bl",
.bus = &platform_bus_type,
.probe = corgibl_probe,
.remove = corgibl_remove,
.suspend = corgibl_suspend,
.resume = corgibl_resume,
};
static int __init corgibl_init(void)
{
return driver_register(&corgibl_driver);
}
static void __exit corgibl_exit(void)
{
driver_unregister(&corgibl_driver);
}
module_init(corgibl_init);
module_exit(corgibl_exit);
MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
MODULE_DESCRIPTION("Corgi Backlight Driver");
MODULE_LICENSE("GPLv2");