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From:   Max Krummenacher <max.oss.09@gmail.com>
To:     max.krummenacher@toradex.com
Cc:     Fabio Estevam <festevam@gmail.com>,
        Krzysztof Kozlowski <krzk+dt@kernel.org>,
        NXP Linux Team <linux-imx@nxp.com>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Rob Herring <robh+dt@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Shawn Guo <shawnguo@kernel.org>, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1 3/3] ARM: dts: imx6qdl-colibri: backlight pwm: Simplify inverted backlight
Date:   Mon,  9 May 2022 13:11:26 +0200
Message-Id: <20220509111126.7032-4-max.oss.09@gmail.com>
In-Reply-To: <20220509111126.7032-1-max.oss.09@gmail.com>
References: <20220509111126.7032-1-max.oss.09@gmail.com>
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From: Max Krummenacher <max.krummenacher@toradex.com>

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@toradex.com>

---

 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