For backlight curves calculated with the CIE 1931 algorithm set the brightness scale type to non-linear. This makes the scale type available to userspace via the 'scale' sysfs attribute.
Signed-off-by: Matthias Kaehlcke mka@chromium.org Tested-by: Enric Balletbo i Serra enric.balletbo@collabora.com Acked-by: Daniel Thompson daniel.thompson@linaro.org --- Changes in v3: - mark scale as non-linear instead of using the CIE1931 type which has been removed - updated commit message
Changes in v2: - added Enric's 'Tested-by' tag - added Daniel's 'Acked-by' tag --- drivers/video/backlight/pwm_bl.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index fb45f866b923..7c6dfc4a601d 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -553,6 +553,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) goto err_alloc; }
+ memset(&props, 0, sizeof(struct backlight_properties)); + if (data->levels) { /* * For the DT case, only when brightness levels is defined @@ -591,6 +593,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pb->levels = data->levels; } + + props.scale = BACKLIGHT_SCALE_NON_LINEAR; } else { /* * That only happens for the non-DT case, where platform data @@ -601,7 +605,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);
- memset(&props, 0, sizeof(struct backlight_properties)); props.type = BACKLIGHT_RAW; props.max_brightness = data->max_brightness; bl = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, pb,