From 511a204638d7d750f859c332635d09f38273b4f0 Mon Sep 17 00:00:00 2001
From: Matthias Kaehlcke <mka@chromium.org>
Date: Tue, 9 Jul 2019 12:00:06 -0700
Subject: backlight: pwm_bl: Set scale type for CIE 1931 curves
Git-commit: 511a204638d7d750f859c332635d09f38273b4f0
Patch-mainline: v5.4-rc1
References: bsc#1152489
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>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
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 2201b8c78641..d6d2b6407d7e 100644
--- 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,
--
2.28.0