arm64: dts: imx8mp-evk: Add PCIe support

Add PCIe support on i.MX8MP EVK board.
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Tested-by: Marek Vasut <marex@denx.de>
Tested-by: Richard Leitner <richard.leitner@skidata.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/imx8mp-evk.dts

@@ -5,6 +5,7 @@
 
 /dts-v1/;
 
+#include <dt-bindings/phy/phy-imx8-pcie.h>
 #include "imx8mp.dtsi"
 
 / {
@@ -33,6 +34,12 @@ memory@40000000 {
 		      <0x1 0x00000000 0 0xc0000000>;
 	};
 
+	pcie0_refclk: pcie0-refclk {
+		compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <100000000>;
+	};
+
 	reg_can1_stby: regulator-can1-stby {
 		compatible = "regulator-fixed";
 		regulator-name = "can1-stby";
@@ -55,6 +62,17 @@ reg_can2_stby: regulator-can2-stby {
 		enable-active-high;
 	};
 
+	reg_pcie0: regulator-pcie {
+		compatible = "regulator-fixed";
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_pcie0_reg>;
+		regulator-name = "MPCIE_3V3";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		gpio = <&gpio2 6 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+	};
+
 	reg_usdhc2_vmmc: regulator-usdhc2 {
 		compatible = "regulator-fixed";
 		pinctrl-names = "default";
@@ -350,6 +368,28 @@ &i2c5 {
 	 */
 };
 
+&pcie_phy {
+	fsl,refclk-pad-mode = <IMX8_PCIE_REFCLK_PAD_INPUT>;
+	clocks = <&pcie0_refclk>;
+	clock-names = "ref";
+	status = "okay";
+};
+
+&pcie {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_pcie0>;
+	reset-gpio = <&gpio2 7 GPIO_ACTIVE_LOW>;
+	clocks = <&clk IMX8MP_CLK_HSIO_ROOT>,
+		 <&clk IMX8MP_CLK_PCIE_ROOT>,
+		 <&clk IMX8MP_CLK_HSIO_AXI>;
+	clock-names = "pcie", "pcie_aux", "pcie_bus";
+	assigned-clocks = <&clk IMX8MP_CLK_PCIE_AUX>;
+	assigned-clock-rates = <10000000>;
+	assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_50M>;
+	vpcie-supply = <&reg_pcie0>;
+	status = "okay";
+};
+
 &snvs_pwrkey {
 	status = "okay";
 };
@@ -502,6 +542,19 @@ MX8MP_IOMUXC_SPDIF_TX__I2C5_SCL         0x400001c2
 		>;
 	};
 
+	pinctrl_pcie0: pcie0grp {
+		fsl,pins = <
+			MX8MP_IOMUXC_I2C4_SCL__PCIE_CLKREQ_B	0x61 /* open drain, pull up */
+			MX8MP_IOMUXC_SD1_DATA5__GPIO2_IO07	0x41
+		>;
+	};
+
+	pinctrl_pcie0_reg: pcie0reggrp {
+		fsl,pins = <
+			MX8MP_IOMUXC_SD1_DATA4__GPIO2_IO06	0x41
+		>;
+	};
+
 	pinctrl_pmic: pmicgrp {
 		fsl,pins = <
 			MX8MP_IOMUXC_GPIO1_IO03__GPIO1_IO03	0x000001c0