linux-imx

/*

 * 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));