diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 550443518891..21866ec69656 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -25,6 +25,7 @@ struct pwm_bl_data { struct pwm_device *pwm; struct device *dev; unsigned int period; + unsigned int lth_brightness; int (*notify)(struct device *, int brightness); }; @@ -48,7 +49,9 @@ static int pwm_backlight_update_status(struct backlight_device *bl) pwm_config(pb->pwm, 0, pb->period); pwm_disable(pb->pwm); } else { - pwm_config(pb->pwm, brightness * pb->period / max, pb->period); + brightness = pb->lth_brightness + + (brightness * (pb->period - pb->lth_brightness) / max); + pwm_config(pb->pwm, brightness, pb->period); pwm_enable(pb->pwm); } return 0; @@ -92,6 +95,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) pb->period = data->pwm_period_ns; pb->notify = data->notify; + pb->lth_brightness = data->lth_brightness * + (data->pwm_period_ns / data->max_brightness); pb->dev = &pdev->dev; pb->pwm = pwm_request(data->pwm_id, "backlight"); diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h index 01b3d759f1fc..e031e1a486d9 100644 --- a/include/linux/pwm_backlight.h +++ b/include/linux/pwm_backlight.h @@ -8,6 +8,7 @@ struct platform_pwm_backlight_data { int pwm_id; unsigned int max_brightness; unsigned int dft_brightness; + unsigned int lth_brightness; unsigned int pwm_period_ns; int (*init)(struct device *dev); int (*notify)(struct device *dev, int brightness);