drivers/video/exynos_pwm_bl.c

   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 }