Re: [PATCH v4 7/8] arm64: dts: imx8mm-evk: Add the pcie support on imx8mm evk board

[Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>]

On Thu, 2021-10-28 at 15:27 +0800, Richard Zhu wrote:
> Add the PCIe support on iMX8MM EVK boards.
> And set the default reference clock mode.
> 
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> ---
>  arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi | 55 +++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi
> index e033d0257b5a..fc1803a8af5b 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi
> @@ -5,6 +5,7 @@
>  
>  /dts-v1/;
>  
> +#include <dt-bindings/phy/phy-imx8-pcie.h>
>  #include <dt-bindings/usb/pd.h>
>  #include "imx8mm.dtsi"
>  
> @@ -30,6 +31,23 @@ status {
>                 };
>         };
>  
> +       pcie0_refclk: pcie0-refclk {
> +               compatible = "fixed-clock";
> +                       #clock-cells = <0>;
> +                       clock-frequency = <100000000>;
> +       };
> +
> +       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 = <&gpio1 5 GPIO_ACTIVE_HIGH>;
> +               enable-active-high;
> +       };
> +
>         reg_usdhc2_vmmc: regulator-usdhc2 {
>                 compatible = "regulator-fixed";
>                 pinctrl-names = "default";
> @@ -289,6 +307,30 @@ pca6416: gpio@20 {
>         };
>  };
>  
> +&pcie_phy {
> +       fsl,refclk-pad-mode = <IMX8_PCIE_REFCLK_PAD_INPUT>;
> +       fsl,tx-deemph-gen1 = <0x2D>;
> +       fsl,tx-deemph-gen2 = <0xF>;

Usually, hex notation uses lower-case letters in device trees.

> +       clocks = <&pcie0_refclk>;
> +       status = "okay";
> +};
> +
> +&pcie0 {
> +       pinctrl-names = "default";
> +       pinctrl-0 = <&pinctrl_pcie0>;
> +       reset-gpio = <&gpio4 21 GPIO_ACTIVE_LOW>;
> +       clocks = <&clk IMX8MM_CLK_PCIE1_ROOT>, <&clk IMX8MM_CLK_PCIE1_AUX>,
> +                <&pcie0_refclk>;
> +       clock-names = "pcie", "pcie_aux", "pcie_bus";
> +       assigned-clocks = <&clk IMX8MM_CLK_PCIE1_AUX>,
> +                         <&clk IMX8MM_CLK_PCIE1_CTRL>;
> +       assigned-clock-rates = <10000000>, <250000000>;
> +       assigned-clock-parents = <&clk IMX8MM_SYS_PLL2_50M>,
> +                                <&clk IMX8MM_SYS_PLL2_250M>;
> +       vpcie-supply = <&reg_pcie0>;
> +       status = "okay";
> +};
> +
>  &sai3 {
>         pinctrl-names = "default";
>         pinctrl-0 = <&pinctrl_sai3>;
> @@ -406,6 +448,19 @@ MX8MM_IOMUXC_I2C3_SDA_I2C3_SDA                     0x400001c3
>                 >;
>         };
>  
> +       pinctrl_pcie0: pcie0grp {
> +               fsl,pins = <
> +                       MX8MM_IOMUXC_I2C4_SCL_PCIE1_CLKREQ_B    0x61
> +                       MX8MM_IOMUXC_SAI2_RXFS_GPIO4_IO21       0x41
> +               >;
> +       };
> +
> +       pinctrl_pcie0_reg: pcie0reggrp {
> +               fsl,pins = <
> +                       MX8MM_IOMUXC_GPIO1_IO05_GPIO1_IO5       0x41
> +               >;
> +       };
> +
>         pinctrl_pmic: pmicirqgrp {
>                 fsl,pins = <
>                         MX8MM_IOMUXC_GPIO1_IO03_GPIO1_IO3               0x141