exynos_pwm_bl.c 923 B

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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@samsung.com>
  6. *
  7. * Derived from linux/drivers/video/backlight/pwm_backlight.c
  8. */
  9. #include <common.h>
  10. #include <pwm.h>
  11. #include <linux/types.h>
  12. #include <asm/io.h>
  13. #include <asm/arch/cpu.h>
  14. #include <asm/arch/gpio.h>
  15. #include <asm/arch/pwm.h>
  16. #include <asm/arch/pwm_backlight.h>
  17. static struct pwm_backlight_data *pwm;
  18. static int exynos_pwm_backlight_update_status(void)
  19. {
  20. int brightness = pwm->brightness;
  21. int max = pwm->max_brightness;
  22. if (brightness == 0) {
  23. pwm_config(pwm->pwm_id, 0, pwm->period);
  24. pwm_disable(pwm->pwm_id);
  25. } else {
  26. pwm_config(pwm->pwm_id,
  27. brightness * pwm->period / max, pwm->period);
  28. pwm_enable(pwm->pwm_id);
  29. }
  30. return 0;
  31. }
  32. int exynos_pwm_backlight_init(struct pwm_backlight_data *pd)
  33. {
  34. pwm = pd;
  35. exynos_pwm_backlight_update_status();
  36. return 0;
  37. }