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      1 // SPDX-License-Identifier: GPL-2.0+
      2 /*
      3  * PWM BACKLIGHT driver for Board based on EXYNOS.
      4  *
      5  * Author: Donghwa Lee  <dh09.lee (at) samsung.com>
      6  *
      7  * Derived from linux/drivers/video/backlight/pwm_backlight.c
      8  */
      9 
     10 #include <common.h>
     11 #include <pwm.h>
     12 #include <linux/types.h>
     13 #include <asm/io.h>
     14 #include <asm/arch/cpu.h>
     15 #include <asm/arch/gpio.h>
     16 #include <asm/arch/pwm.h>
     17 #include <asm/arch/pwm_backlight.h>
     18 
     19 static struct pwm_backlight_data *pwm;
     20 
     21 static int exynos_pwm_backlight_update_status(void)
     22 {
     23 	int brightness = pwm->brightness;
     24 	int max = pwm->max_brightness;
     25 
     26 	if (brightness == 0) {
     27 		pwm_config(pwm->pwm_id, 0, pwm->period);
     28 		pwm_disable(pwm->pwm_id);
     29 	} else {
     30 		pwm_config(pwm->pwm_id,
     31 			brightness * pwm->period / max, pwm->period);
     32 		pwm_enable(pwm->pwm_id);
     33 	}
     34 	return 0;
     35 }
     36 
     37 int exynos_pwm_backlight_init(struct pwm_backlight_data *pd)
     38 {
     39 	pwm = pd;
     40 
     41 	exynos_pwm_backlight_update_status();
     42 
     43 	return 0;
     44 }
     45