i.MX ProcessorsのトピックUsing PCIe on i.MX8MP with internal clock on Linux-imx 6.1.36

Using PCIe on i.MX8MP with internal clock on Linux-imx 6.1.36

Redman — Wed, 29 Nov 2023 14:41:24 GMT

Hello everyone,

I'm trying to set up the dts to use the PCIe interface on a uSOM equipped with an i.MX8MP processor. I know for sure that the hardware is ok because I'm using the uSOM with a development board and everything is ok when using the linux-imx 5.15.32.
The problems arise when using the latest linux-imx 6.1.36: I get a " phy phy-32f00000.pcie-phy.2: phy poweron failed --> -110" in the dmesg, a symptom that the PCIe PHY is not being properly clocked.

The dts fragment for the PCIe is the following:

&pcie_phy { fsl,refclk-pad-mode = <IMX8_PCIE_REFCLK_PAD_UNUSED>; clocks = <&clk IMX8MP_CLK_HSIO_AXI>; clock-names = "ref"; status = "okay"; }; &pcie { reset-gpio = <&pca9555 0 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>; status = "okay"; }; &pcie_ep { 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_HSIO_AXI>, <&clk IMX8MP_CLK_PCIE_AUX>; assigned-clock-rates = <500000000>, <10000000>; assigned-clock-parents = <&clk IMX8MP_SYS_PLL2_500M>, <&clk IMX8MP_SYS_PLL2_50M>; status = "disabled"; };

Can someone point me out what is missing, please?

Thank you!

Re: Using PCIe on i.MX8MP with internal clock on Linux-imx 6.1.36

JorgeCas — Wed, 29 Nov 2023 16:21:55 GMT

Hello, I hope you are doing well.

This issue was reported before, I will attach a working reference DTS and 4 patches that need to be applied.

pcie0_refclk: pcie0-refclk { compatible = "fixed-clock"; #clock-cells = <0>; clock-frequency = <100000000>; }; reg_pcie0: regulator-pcie { compatible = "regulator-fixed"; regulator-name = "MPCIE_3V3"; regulator-min-microvolt = <3300000>; regulator-max-microvolt = <3300000>; gpio = <&gpio2 6 GPIO_ACTIVE_HIGH>; enable-active-high; regulator-always-on; }; &pcie_phy { fsl,refclk-pad-mode = <IMX8_PCIE_REFCLK_PAD_OUTPUT>; clocks = <&hsio_blk_ctrl>; clock-names = "ref"; status = "okay"; }; &pcie { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_pcie0>; reset-gpio = <&gpio1 12 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"; };

Patches:

https://www.spinics.net/lists/devicetree/msg558950.html
https://www.spinics.net/lists/devicetree/msg558947.html
https://www.spinics.net/lists/devicetree/msg558949.html
https://www.spinics.net/lists/devicetree/msg558948.html

Please let me know if helps with your issue.

Best regards.

Re: Using PCIe on i.MX8MP with internal clock on Linux-imx 6.1.36

Redman — Sat, 02 Dec 2023 13:19:31 GMT

Hello!
Problem solved, thanks for your help!

Re: Using PCIe on i.MX8MP with internal clock on Linux-imx 6.1.36

shlomz — Mon, 20 Jan 2025 21:32:41 GMT

HI,

I have the same issue when using the pcie as pcie_ep.

can you please add the relevant changes for this mode ?

thanks