u-boot/drivers/video/exynos_pwm_bl.c
Donghwa Lee 6fff52b93a video: support exynos pwm backlight driver
This patch support exynos pwm backlight driver. It can control backlight
power and brightness by using pwm.

Signed-off-by: Donghwa Lee <dh09.lee@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2012-09-01 14:58:24 +02:00

57 lines
1.6 KiB
C

/*
* PWM BACKLIGHT driver for Board based on EXYNOS.
*
* Author: Donghwa Lee <dh09.lee@samsung.com>
*
* Derived from linux/drivers/video/backlight/pwm_backlight.c
*
* 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.
*
* 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.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <common.h>
#include <pwm.h>
#include <linux/types.h>
#include <asm/io.h>
#include <asm/arch/cpu.h>
#include <asm/arch/gpio.h>
#include <asm/arch/pwm.h>
#include <asm/arch/pwm_backlight.h>
static struct pwm_backlight_data *pwm;
static int exynos_pwm_backlight_update_status(void)
{
int brightness = pwm->brightness;
int max = pwm->max_brightness;
if (brightness == 0) {
pwm_config(pwm->pwm_id, 0, pwm->period);
pwm_disable(pwm->pwm_id);
} else {
pwm_config(pwm->pwm_id,
brightness * pwm->period / max, pwm->period);
pwm_enable(pwm->pwm_id);
}
return 0;
}
int exynos_pwm_backlight_init(struct pwm_backlight_data *pd)
{
pwm = pd;
exynos_pwm_backlight_update_status();
return 0;
}