arm64: dts: qcom: msm8916-samsung-fortuna: Add PWM backlight

Most of the Galaxy Grand Prime use backlight drivers controlled with PWM
signal.
To simplify the description, add the backlight with the necessary clk-pwm
to the common dtsi.
Signed-off-by: Siddharth Manthan <siddharth.manthan@gmail.com>
[Stephan: Move to fortuna-common and disable on rossa-common]
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
[Raymond: Add the commit message]
Signed-off-by: Raymond Hackley <raymondhackley@protonmail.com>
Link: https://lore.kernel.org/r/20240404121703.17086-3-raymondhackley@protonmail.comSigned-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm64/boot/dts/qcom/msm8916-samsung-fortuna-common.dtsi

@@ -26,6 +26,30 @@ tz-apps@85a00000 {
 		};
 	};
 
+	clk_pwm_backlight: backlight {
+		compatible = "pwm-backlight";
+		pwms = <&clk_pwm 0 100000>;
+
+		enable-gpios = <&tlmm 98 GPIO_ACTIVE_HIGH>;
+
+		brightness-levels = <0 255>;
+		num-interpolated-steps = <255>;
+		default-brightness-level = <128>;
+
+		pinctrl-0 = <&backlight_en_default>;
+		pinctrl-names = "default";
+	};
+
+	clk_pwm: pwm {
+		compatible = "clk-pwm";
+		#pwm-cells = <2>;
+
+		clocks = <&gcc GCC_GP2_CLK>;
+
+		pinctrl-0 = <&backlight_pwm_default>;
+		pinctrl-names = "default";
+	};
+
 	gpio-keys {
 		compatible = "gpio-keys";
 
@@ -199,6 +223,18 @@ &wcnss_mem {
 };
 
 &tlmm {
+	backlight_en_default: backlight-en-default-state {
+		pins = "gpio98";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-disable;
+	};
+
+	backlight_pwm_default: backlight-pwm-default-state {
+		pins = "gpio50";
+		function = "gcc_gp2_clk_a";
+	};
+
 	fg_alert_default: fg-alert-default-state {
 		pins = "gpio121";
 		function = "gpio";

arch/arm64/boot/dts/qcom/msm8916-samsung-rossa-common.dtsi

@@ -17,3 +17,12 @@ muic: extcon@14 {
 		pinctrl-names = "default";
 	};
 };
+
+/* On rossa backlight is controlled with MIPI DCS commands */
+&clk_pwm {
+	status = "disabled";
+};
+
+&clk_pwm_backlight {
+	status = "disabled";
+};