The front panel LED on the Cubox-i is driven by one of the iMX6 PWM
channels, and is wired between the PWM output and supply. This means
that outputting a low level results in the LED being turned on, so we
need the duty cycle inverted.
There's a question about whether the output inversion should be at the
pwm or pwm-leds level - setting the output inversion bit in the iMX6
results in a PWM duty cycle of zero outputting logic zero, meaning that
the LED is fully on. This is undesirable, as it becomes impossible to
turn the LED fully off.
Signed-off-by: Russell King <redacted>
---
arch/arm/boot/dts/imx6qdl-cubox-i.dtsi | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/arch/arm/boot/dts/imx6qdl-cubox-i.dtsi b/arch/arm/boot/dts/imx6qdl-cubox-i.dtsi
index c2a24888a276..7971387c2e13 100644
--- a/arch/arm/boot/dts/imx6qdl-cubox-i.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-cubox-i.dtsi
@@ -12,6 +12,20 @@
pinctrl-0 = <&pinctrl_cubox_i_ir>;
};
+ pwmleds {
+ compatible = "pwm-leds";
+ pinctrl-names = "default";
+ pinctrl-0 = <&pinctrl_cubox_i_pwm1>;
+
+ front {
+ active-low;
+ default-brightness = <128>;
+ label = "imx6:red:front";
+ max-brightness = <248>;
+ pwms = <&pwm1 0 50000>;
+ };
+ };
+
regulators {
compatible = "simple-bus";
@@ -82,6 +96,10 @@
>;
};
+ pinctrl_cubox_i_pwm1: cubox-i-pwm1-front-led {
+ fsl,pins = <MX6QDL_PAD_DISP0_DAT8__PWM1_OUT 0x1b0b0>;
+ };
+
pinctrl_cubox_i_spdif: cubox-i-spdif {
fsl,pins = <MX6QDL_PAD_GPIO_17__SPDIF_OUT 0x13091>;
};--
1.8.3.1