@@ -5,6 +5,8 @@ Required properties:
- reg: slave address
Optional properties:
+- default-brightness: brightness value on boot, value from: 0-4095
+ default: 2048
- label: The name of the backlight device
- qcom,cs-out: bool; enable current sink output
- qcom,cabc: bool; enable content adaptive backlight control
@@ -17,6 +17,9 @@
#include <linux/of_device.h>
#include <linux/regmap.h>
+/* From DT binding */
+#define PM8941_WLED_DEFAULT_BRIGHTNESS 2048
+
#define PM8941_WLED_REG_VAL_BASE 0x40
#define PM8941_WLED_REG_VAL_MAX 0xFFF
@@ -373,6 +376,7 @@ static int pm8941_wled_probe(struct platform_device *pdev)
struct backlight_device *bl;
struct pm8941_wled *wled;
struct regmap *regmap;
+ u32 val;
int rc;
regmap = dev_get_regmap(pdev->dev.parent, NULL);
@@ -395,8 +399,12 @@ static int pm8941_wled_probe(struct platform_device *pdev)
if (rc)
return rc;
+ val = PM8941_WLED_DEFAULT_BRIGHTNESS;
+ of_property_read_u32(pdev->dev.of_node, "default-brightness", &val);
+
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_RAW;
+ props.brightness = val;
props.max_brightness = PM8941_WLED_REG_VAL_MAX;
bl = devm_backlight_device_register(&pdev->dev, wled->name,
&pdev->dev, wled,
Default the brightness to 2048 and add possibility to override this in device tree. Suggested-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> --- After going back and forth on this one I decided that the best unit of this property (which could become a common backlight property) would be to use "units of brightness". The value will either come from the boot loader picking a value in some way or from a user finding a good value by tweaking sysfs - both which will be in "units of brightness". Documentation/devicetree/bindings/video/backlight/pm8941-wled.txt | 2 ++ drivers/video/backlight/pm8941-wled.c | 8 ++++++++ 2 files changed, 10 insertions(+)