backlight: pwm_bl: Set scale type for CIE 1931 curves

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>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 2201b8c786419d4df61726876895f97e5780fac5..d6d2b6407d7e1a72d7927ca90bb20f25a4f1ef01 100644 (file)
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -536,6 +536,8 @@ 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
@@ -574,6 +576,8 @@ 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
@@ -584,7 +588,6 @@ 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,