arm64: dts: mediatek: cherry: Add platform regulators layout and config

Add the regulators layout for this platform, including the basic power
rails controlled by the EC (and/or always on).
Moreover, include the MT6359 PMIC devicetree and add some configuration
for its regulators, essential to keep the machine alive after booting.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220704101321.44835-4-angelogioacchino.delregno@collabora.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi

@@ -5,6 +5,7 @@
 
 #include <dt-bindings/gpio/gpio.h>
 #include "mt8195.dtsi"
+#include "mt6359.dtsi"
 
 / {
 	aliases {
@@ -19,6 +20,109 @@ memory@40000000 {
 		device_type = "memory";
 		reg = <0 0x40000000 0 0x80000000>;
 	};
+
+	/* system wide LDO 3.3V power rail */
+	pp3300_z5: regulator-pp3300-ldo-z5 {
+		compatible = "regulator-fixed";
+		regulator-name = "pp3300_ldo_z5";
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		vin-supply = <&ppvar_sys>;
+	};
+
+	/* separately switched 3.3V power rail */
+	pp3300_s3: regulator-pp3300-s3 {
+		compatible = "regulator-fixed";
+		regulator-name = "pp3300_s3";
+		/* automatically sequenced by PMIC EXT_PMIC_EN2 */
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		vin-supply = <&pp3300_z2>;
+	};
+
+	/* system wide 3.3V power rail */
+	pp3300_z2: regulator-pp3300-z2 {
+		compatible = "regulator-fixed";
+		regulator-name = "pp3300_z2";
+		/* EN pin tied to pp4200_z2, which is controlled by EC */
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		vin-supply = <&ppvar_sys>;
+	};
+
+	/* system wide 4.2V power rail */
+	pp4200_z2: regulator-pp4200-z2 {
+		compatible = "regulator-fixed";
+		regulator-name = "pp4200_z2";
+		/* controlled by EC */
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <4200000>;
+		regulator-max-microvolt = <4200000>;
+		vin-supply = <&ppvar_sys>;
+	};
+
+	/* system wide switching 5.0V power rail */
+	pp5000_s5: regulator-pp5000-s5 {
+		compatible = "regulator-fixed";
+		regulator-name = "pp5000_s5";
+		/* controlled by EC */
+		regulator-always-on;
+		regulator-boot-on;
+		regulator-min-microvolt = <5000000>;
+		regulator-max-microvolt = <5000000>;
+		vin-supply = <&ppvar_sys>;
+	};
+
+	/* system wide semi-regulated power rail from battery or USB */
+	ppvar_sys: regulator-ppvar-sys {
+		compatible = "regulator-fixed";
+		regulator-name = "ppvar_sys";
+		regulator-always-on;
+		regulator-boot-on;
+	};
+};
+
+/* for CPU-L */
+&mt6359_vcore_buck_reg {
+	regulator-always-on;
+};
+
+/* for CORE */
+&mt6359_vgpu11_buck_reg {
+	regulator-always-on;
+};
+
+&mt6359_vgpu11_sshub_buck_reg {
+	regulator-always-on;
+	regulator-min-microvolt = <550000>;
+	regulator-max-microvolt = <550000>;
+};
+
+/* for CORE SRAM */
+&mt6359_vpu_buck_reg {
+	regulator-always-on;
+};
+
+&mt6359_vrf12_ldo_reg {
+	regulator-always-on;
+};
+
+/* for GPU SRAM */
+&mt6359_vsram_others_ldo_reg {
+	regulator-always-on;
+	regulator-min-microvolt = <750000>;
+	regulator-max-microvolt = <750000>;
+};
+
+&mt6359_vufs_ldo_reg {
+	regulator-always-on;
 };
 
 &uart0 {