linux-imx

/*

 *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>

 *      PCF50633 backlight device driver

 *

 *  This program is free software; you can redistribute  it and/or modify it

 *  under  the terms of  the GNU General  Public License as published by the

 *  Free Software Foundation;  either version 2 of the  License, or (at your

 *  option) any later version.

 *

 *  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.,

 *  675 Mass Ave, Cambridge, MA 02139, USA.

 *

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/platform_device.h>

​

#include <linux/backlight.h>

#include <linux/fb.h>

​

#include <linux/mfd/pcf50633/core.h>

#include <linux/mfd/pcf50633/backlight.h>

​

struct pcf50633_bl {

    struct pcf50633 *pcf;

    struct backlight_device *bl;

​

    unsigned int brightness;

    unsigned int brightness_limit;

};

​

/*

 * pcf50633_bl_set_brightness_limit

 *

 * Update the brightness limit for the pc50633 backlight. The actual brightness

 * will not go above the limit. This is useful to limit power drain for example

 * on low battery.

 *

 * @dev: Pointer to a pcf50633 device

 * @limit: The brightness limit. Valid values are 0-63

 */

int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit)

{

    struct pcf50633_bl *pcf_bl = platform_get_drvdata(pcf->bl_pdev);

​

    if (!pcf_bl)

        return -ENODEV;

​

    pcf_bl->brightness_limit = limit & 0x3f;

    backlight_update_status(pcf_bl->bl);

​

    return 0;

}

​

static int pcf50633_bl_update_status(struct backlight_device *bl)

{

    struct pcf50633_bl *pcf_bl = bl_get_data(bl);

    unsigned int new_brightness;

​

​