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-rw-r--r--drivers/video/backlight/pwm_bl.c7
-rw-r--r--include/linux/pwm_backlight.h1
2 files changed, 7 insertions, 1 deletions
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);