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/*
* linux/drivers/video/backlight/aat2870_bl.c
*
* Copyright (c) 2011, NVIDIA Corporation.
* Author: Jin Park <jinyoungp@nvidia.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/mfd/aat2870.h>
struct aat2870_bl_driver_data {
struct platform_device *pdev;
struct backlight_device *bd;
int channels;
int max_current;
int brightness; /* current brightness */
};
static inline int aat2870_brightness(struct aat2870_bl_driver_data *aat2870_bl,
int brightness)
{
struct backlight_device *bd = aat2870_bl->bd;
int val;
val = brightness * (aat2870_bl->max_current - 1);
val /= bd->props.max_brightness;
return val;
}
static inline int aat2870_bl_enable(struct aat2870_bl_driver_data *aat2870_bl)
{
struct aat2870_data *aat2870
= dev_get_drvdata(aat2870_bl->pdev->dev.parent);
return aat2870->write(aat2870, AAT2870_BL_CH_EN,
(u8)aat2870_bl->channels);
}
static inline int aat2870_bl_disable(struct aat2870_bl_driver_data *aat2870_bl)
{
struct aat2870_data *aat2870
= dev_get_drvdata(aat2870_bl->pdev->dev.parent);
return aat2870->write(aat2870, AAT2870_BL_CH_EN, 0x0);
}
static int aat2870_bl_update_status(struct backlight_device *bd)
{
struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bd);
struct aat2870_data *aat2870 =
dev_get_drvdata(aat2870_bl->pdev->dev.parent);
int brightness = bd->props.brightness;
int ret;
if ((brightness < 0) || (bd->props.max_brightness < brightness)) {
dev_err(&bd->dev, "invalid brightness, %d\n", brightness);
return -EINVAL;
}
dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n",
bd->props.brightness, bd->props.power, bd->props.state);
if ((bd->props.power != FB_BLANK_UNBLANK) ||
(bd->props.state & BL_CORE_FBBLANK) ||
(bd->props.state & BL_CORE_SUSPENDED))
brightness = 0;
ret = aat2870->write(aat2870, AAT2870_BLM,
(u8)aat2870_brightness(aat2870_bl, brightness));
if (ret < 0)
return ret;
if (brightness == 0) {
ret = aat2870_bl_disable(aat2870_bl);
if (ret < 0)
return ret;
} else if (aat2870_bl->brightness == 0) {
ret = aat2870_bl_enable(aat2870_bl);
if (ret < 0)
return ret;
}
aat2870_bl->brightness = brightness;
return 0;
}
static int aat2870_bl_check_fb(struct backlight_device *bd, struct fb_info *fi)
{
return 1;
}
static const struct backlight_ops aat2870_bl_ops = {
.options = BL_CORE_SUSPENDRESUME,
.update_status = aat2870_bl_update_status,
.check_fb = aat2870_bl_check_fb,
};
static int aat2870_bl_probe(struct platform_device *pdev)
{
struct aat2870_bl_platform_data *pdata = dev_get_platdata(&pdev->dev);
struct aat2870_bl_driver_data *aat2870_bl;
struct backlight_device *bd;
struct backlight_properties props;
int ret = 0;
if (!pdata) {
dev_err(&pdev->dev, "No platform data\n");
ret = -ENXIO;
goto out;
}
if (pdev->id != AAT2870_ID_BL) {
dev_err(&pdev->dev, "Invalid device ID, %d\n", pdev->id);
ret = -EINVAL;
goto out;
}
aat2870_bl = devm_kzalloc(&pdev->dev,
sizeof(struct aat2870_bl_driver_data),
GFP_KERNEL);
if (!aat2870_bl) {
ret = -ENOMEM;
goto out;
}
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
bd = devm_backlight_device_register(&pdev->dev, "aat2870-backlight",
&pdev->dev, aat2870_bl, &aat2870_bl_ops,
&props);
if (IS_ERR(bd)) {
dev_err(&pdev->dev,
"Failed allocate memory for backlight device\n");
ret = PTR_ERR(bd);
goto out;
}
aat2870_bl->pdev = pdev;
platform_set_drvdata(pdev, aat2870_bl);
aat2870_bl->bd = bd;
if (pdata->channels > 0)
aat2870_bl->channels = pdata->channels;
else
aat2870_bl->channels = AAT2870_BL_CH_ALL;
if (pdata->max_current > 0)
aat2870_bl->max_current = pdata->max_current;
else
aat2870_bl->max_current = AAT2870_CURRENT_27_9;
if (pdata->max_brightness > 0)
bd->props.max_brightness = pdata->max_brightness;
else
bd->props.max_brightness = 255;
aat2870_bl->brightness = 0;
bd->props.power = FB_BLANK_UNBLANK;
bd->props.brightness = bd->props.max_brightness;
ret = aat2870_bl_update_status(bd);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to initialize\n");
return ret;
}
return 0;
out:
return ret;
}
static int aat2870_bl_remove(struct platform_device *pdev)
{
struct aat2870_bl_driver_data *aat2870_bl = platform_get_drvdata(pdev);
struct backlight_device *bd = aat2870_bl->bd;
bd->props.power = FB_BLANK_POWERDOWN;
bd->props.brightness = 0;
backlight_update_status(bd);
return 0;
}
static struct platform_driver aat2870_bl_driver = {
.driver = {
.name = "aat2870-backlight",
},
.probe = aat2870_bl_probe,
.remove = aat2870_bl_remove,
};
static int __init aat2870_bl_init(void)
{
return platform_driver_register(&aat2870_bl_driver);
}
subsys_initcall(aat2870_bl_init);
static void __exit aat2870_bl_exit(void)
{
platform_driver_unregister(&aat2870_bl_driver);
}
module_exit(aat2870_bl_exit);
MODULE_DESCRIPTION("AnalogicTech AAT2870 Backlight");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jin Park <jinyoungp@nvidia.com>");
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