ubuntu-linux-kernel/drivers/video/backlight/generic_bl.c

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2024-04-01 15:06:58 +00:00
/*
* Generic Backlight Driver
*
* Copyright (c) 2004-2008 Richard Purdie
*
* 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 genericbl_intensity;
static struct backlight_device *generic_backlight_device;
static struct generic_bl_info *bl_machinfo;
/* Flag to signal when the battery is low */
#define GENERICBL_BATTLOW BL_CORE_DRIVER1
static int genericbl_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
if (bd->props.power != FB_BLANK_UNBLANK)
intensity = 0;
if (bd->props.state & BL_CORE_FBBLANK)
intensity = 0;
if (bd->props.state & BL_CORE_SUSPENDED)
intensity = 0;
if (bd->props.state & GENERICBL_BATTLOW)
intensity &= bl_machinfo->limit_mask;
bl_machinfo->set_bl_intensity(intensity);
genericbl_intensity = intensity;
if (bl_machinfo->kick_battery)
bl_machinfo->kick_battery();
return 0;
}
static int genericbl_get_intensity(struct backlight_device *bd)
{
return genericbl_intensity;
}
static const struct backlight_ops genericbl_ops = {
.options = BL_CORE_SUSPENDRESUME,
.get_brightness = genericbl_get_intensity,
.update_status = genericbl_send_intensity,
};
static int genericbl_probe(struct platform_device *pdev)
{
struct backlight_properties props;
struct generic_bl_info *machinfo = dev_get_platdata(&pdev->dev);
const char *name = "generic-bl";
struct backlight_device *bd;
bl_machinfo = machinfo;
if (!machinfo->limit_mask)
machinfo->limit_mask = -1;
if (machinfo->name)
name = machinfo->name;
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
props.max_brightness = machinfo->max_intensity;
bd = devm_backlight_device_register(&pdev->dev, name, &pdev->dev,
NULL, &genericbl_ops, &props);
if (IS_ERR(bd))
return PTR_ERR(bd);
platform_set_drvdata(pdev, bd);
bd->props.power = FB_BLANK_UNBLANK;
bd->props.brightness = machinfo->default_intensity;
backlight_update_status(bd);
generic_backlight_device = bd;
dev_info(&pdev->dev, "Generic Backlight Driver Initialized.\n");
return 0;
}
static int genericbl_remove(struct platform_device *pdev)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
bd->props.power = 0;
bd->props.brightness = 0;
backlight_update_status(bd);
dev_info(&pdev->dev, "Generic Backlight Driver Unloaded\n");
return 0;
}
static struct platform_driver genericbl_driver = {
.probe = genericbl_probe,
.remove = genericbl_remove,
.driver = {
.name = "generic-bl",
},
};
module_platform_driver(genericbl_driver);
MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
MODULE_DESCRIPTION("Generic Backlight Driver");
MODULE_LICENSE("GPL");