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linux/drivers/video/backlight/corgi_bl.c

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/*
* Backlight Driver for Sharp Zaurus Handhelds (various models)
*
* Copyright (c) 2004-2006 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/platform_device.h>
#include <linux/mutex.h>
#include <linux/fb.h>
#include <linux/backlight.h>
static int corgibl_intensity;
static struct backlight_properties corgibl_data;
static struct backlight_device *corgi_backlight_device;
static struct generic_bl_info *bl_machinfo;
static unsigned long corgibl_flags;
#define CORGIBL_SUSPENDED 0x01
#define CORGIBL_BATTLOW 0x02
static int corgibl_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
if (bd->props.power != FB_BLANK_UNBLANK)
intensity = 0;
if (bd->props.fb_blank != FB_BLANK_UNBLANK)
intensity = 0;
if (corgibl_flags & CORGIBL_SUSPENDED)
intensity = 0;
if (corgibl_flags & CORGIBL_BATTLOW)
intensity &= bl_machinfo->limit_mask;
bl_machinfo->set_bl_intensity(intensity);
corgibl_intensity = intensity;
if (bl_machinfo->kick_battery)
bl_machinfo->kick_battery();
return 0;
}
#ifdef CONFIG_PM
static int corgibl_suspend(struct platform_device *pdev, pm_message_t state)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
corgibl_flags |= CORGIBL_SUSPENDED;
backlight_update_status(bd);
return 0;
}
static int corgibl_resume(struct platform_device *pdev)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
corgibl_flags &= ~CORGIBL_SUSPENDED;
backlight_update_status(bd);
return 0;
}
#else
#define corgibl_suspend NULL
#define corgibl_resume NULL
#endif
static int corgibl_get_intensity(struct backlight_device *bd)
{
return corgibl_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)
{
if (limit)
corgibl_flags |= CORGIBL_BATTLOW;
else
corgibl_flags &= ~CORGIBL_BATTLOW;
backlight_update_status(corgi_backlight_device);
}
EXPORT_SYMBOL(corgibl_limit_intensity);
static struct backlight_ops corgibl_ops = {
.get_brightness = corgibl_get_intensity,
.update_status = corgibl_send_intensity,
};
static int corgibl_probe(struct platform_device *pdev)
{
struct generic_bl_info *machinfo = pdev->dev.platform_data;
const char *name = "generic-bl";
bl_machinfo = machinfo;
if (!machinfo->limit_mask)
machinfo->limit_mask = -1;
if (machinfo->name)
name = machinfo->name;
corgi_backlight_device = backlight_device_register (name,
&pdev->dev, NULL, &corgibl_ops);
if (IS_ERR (corgi_backlight_device))
return PTR_ERR (corgi_backlight_device);
platform_set_drvdata(pdev, corgi_backlight_device);
corgi_backlight_device->props.max_brightness = machinfo->max_intensity;
corgi_backlight_device->props.power = FB_BLANK_UNBLANK;
corgi_backlight_device->props.brightness = machinfo->default_intensity;
backlight_update_status(corgi_backlight_device);
printk("Corgi Backlight Driver Initialized.\n");
return 0;
}
static int corgibl_remove(struct platform_device *pdev)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
corgibl_data.power = 0;
corgibl_data.brightness = 0;
backlight_update_status(bd);
backlight_device_unregister(bd);
printk("Corgi Backlight Driver Unloaded\n");
return 0;
}
static struct platform_driver corgibl_driver = {
.probe = corgibl_probe,
.remove = corgibl_remove,
.suspend = corgibl_suspend,
.resume = corgibl_resume,
.driver = {
.name = "generic-bl",
},
};
static int __init corgibl_init(void)
{
return platform_driver_register(&corgibl_driver);
}
static void __exit corgibl_exit(void)
{
platform_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("GPL");