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/*
* Copyright 2007-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
/*!
* @defgroup LCDC_BL MXC LCDC Backlight Driver
*/
/*!
* @file mxc_lcdc_bl.c
*
* @brief Backlight Driver for LCDC PWM on Freescale MXC/i.MX platforms.
*
* This file contains API defined in include/linux/clk.h for setting up and
* retrieving clocks.
*
* Based on Sharp's Corgi Backlight Driver
*
* @ingroup LCDC_BL
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/clk.h>
#define MXC_MAX_INTENSITY 255
#define MXC_DEFAULT_INTENSITY 127
#define MXC_INTENSITY_OFF 0
extern void mx2fb_set_brightness(uint8_t);
struct mxcbl_dev_data {
struct clk *clk;
int intensity;
};
static int mxcbl_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
struct mxcbl_dev_data *devdata = dev_get_drvdata(&bd->dev);
if (bd->props.power != FB_BLANK_UNBLANK)
intensity = 0;
if (bd->props.fb_blank != FB_BLANK_UNBLANK)
intensity = 0;
if ((devdata->intensity == 0) && (intensity != 0))
clk_enable(devdata->clk);
/* PWM contrast control register */
mx2fb_set_brightness(intensity);
if ((devdata->intensity != 0) && (intensity == 0))
clk_disable(devdata->clk);
devdata->intensity = intensity;
return 0;
}
static int mxcbl_get_intensity(struct backlight_device *bd)
{
struct mxcbl_dev_data *devdata = dev_get_drvdata(&bd->dev);
return devdata->intensity;
}
static int mxcbl_check_fb(struct backlight_device *bd, struct fb_info *info)
{
if (strcmp(info->fix.id, "DISP0 BG") == 0) {
return 1;
}
return 0;
}
static struct backlight_ops mxcbl_ops = {
.get_brightness = mxcbl_get_intensity,
.update_status = mxcbl_send_intensity,
.check_fb = mxcbl_check_fb,
};
static int __init mxcbl_probe(struct platform_device *pdev)
{
struct backlight_device *bd;
struct mxcbl_dev_data *devdata;
struct backlight_properties props;
int ret = 0;
devdata = kzalloc(sizeof(struct mxcbl_dev_data), GFP_KERNEL);
if (!devdata)
return -ENOMEM;
devdata->clk = clk_get(NULL, "lcdc_clk");
memset(&props, 0, sizeof(struct backlight_properties));
props.max_brightness = MXC_MAX_INTENSITY;
bd = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, devdata,
&mxcbl_ops, &props);
if (IS_ERR(bd)) {
ret = PTR_ERR(bd);
goto err0;
}
platform_set_drvdata(pdev, bd);
bd->props.brightness = MXC_DEFAULT_INTENSITY;
bd->props.power = FB_BLANK_UNBLANK;
bd->props.fb_blank = FB_BLANK_UNBLANK;
mx2fb_set_brightness(MXC_DEFAULT_INTENSITY);
printk("MXC Backlight Device %s Initialized.\n", dev_name(&pdev->dev));
return 0;
err0:
kfree(devdata);
return ret;
}
static int mxcbl_remove(struct platform_device *pdev)
{
struct backlight_device *bd = platform_get_drvdata(pdev);
bd->props.brightness = MXC_INTENSITY_OFF;
backlight_update_status(bd);
backlight_device_unregister(bd);
return 0;
}
static struct platform_driver mxcbl_driver = {
.probe = mxcbl_probe,
.remove = mxcbl_remove,
.driver = {
.name = "mxc_lcdc_bl",
},
};
static int __init mxcbl_init(void)
{
return platform_driver_register(&mxcbl_driver);
}
static void __exit mxcbl_exit(void)
{
platform_driver_unregister(&mxcbl_driver);
}
module_init(mxcbl_init);
module_exit(mxcbl_exit);
MODULE_DESCRIPTION("Freescale MXC/i.MX LCDC PWM Backlight Driver");
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_LICENSE("GPL");
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