[PATCH v1 3/3] ARM: dts: imx6qdl-colibri: backlight pwm: Simplify inverted backlight

From: Max Krummenacher
Date: Mon May 09 2022 - 07:12:57 EST


From: Max Krummenacher <max.krummenacher@xxxxxxxxxxx>

Set #pwm-cells to the default 3 to gain access to the parameter
which allows inverting the PWM signal. This is useful to specify
a backlight which has its highest brightness at 0.

Also adapt the brightness steps as the backlight doesn't light up
for very low duty cycles.

Signed-off-by: Max Krummenacher <max.krummenacher@xxxxxxxxxxx>

---

arch/arm/boot/dts/imx6qdl-colibri.dtsi | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/imx6qdl-colibri.dtsi b/arch/arm/boot/dts/imx6qdl-colibri.dtsi
index f0908b530f86..023e76215064 100644
--- a/arch/arm/boot/dts/imx6qdl-colibri.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-colibri.dtsi
@@ -6,6 +6,7 @@
*/

#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/pwm/pwm.h>

/ {
model = "Toradex Colibri iMX6DL/S Module";
@@ -13,13 +14,13 @@

backlight: backlight {
compatible = "pwm-backlight";
- brightness-levels = <0 127 191 223 239 247 251 255>;
- default-brightness-level = <1>;
+ brightness-levels = <0 45 63 88 119 158 203 255>;
+ default-brightness-level = <4>;
enable-gpios = <&gpio3 26 GPIO_ACTIVE_HIGH>; /* Colibri BL_ON */
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_gpio_bl_on>;
power-supply = <&reg_module_3v3>;
- pwms = <&pwm3 0 5000000>;
+ pwms = <&pwm3 0 5000000 PWM_POLARITY_INVERTED>;
status = "disabled";
};

@@ -620,7 +621,6 @@

/* Colibri PWM<A> */
&pwm3 {
- #pwm-cells = <2>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_pwm3>;
status = "disabled";
--
2.20.1