1 /* 2 * PWM BACKLIGHT driver for Board based on EXYNOS. 3 * 4 * Author: Donghwa Lee <dh09.lee@samsung.com> 5 * 6 * Derived from linux/drivers/video/backlight/pwm_backlight.c 7 * 8 * SPDX-License-Identifier: GPL-2.0+ 9 */ 10 11 #include <common.h> 12 #include <pwm.h> 13 #include <linux/types.h> 14 #include <asm/io.h> 15 #include <asm/arch/cpu.h> 16 #include <asm/arch/gpio.h> 17 #include <asm/arch/pwm.h> 18 #include <asm/arch/pwm_backlight.h> 19 20 static struct pwm_backlight_data *pwm; 21 22 static int exynos_pwm_backlight_update_status(void) 23 { 24 int brightness = pwm->brightness; 25 int max = pwm->max_brightness; 26 27 if (brightness == 0) { 28 pwm_config(pwm->pwm_id, 0, pwm->period); 29 pwm_disable(pwm->pwm_id); 30 } else { 31 pwm_config(pwm->pwm_id, 32 brightness * pwm->period / max, pwm->period); 33 pwm_enable(pwm->pwm_id); 34 } 35 return 0; 36 } 37 38 int exynos_pwm_backlight_init(struct pwm_backlight_data *pd) 39 { 40 pwm = pd; 41 42 exynos_pwm_backlight_update_status(); 43 44 return 0; 45 } 46