Re: [PATCH v5 2/8] dt-bindings: phy: Add imx8 pcie phy driver support

From: Rob Herring
Date: Tue Nov 02 2021 - 12:40:48 EST


On Tue, Nov 02, 2021 at 10:32:29AM +0800, Richard Zhu wrote:
> Add dt-binding for the standalone i.MX8 PCIe PHY driver.
>
> Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> Reviewed-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> Tested-by: Tim Harvey <tharvey@xxxxxxxxxxxxx>
> ---
> .../bindings/phy/fsl,imx8-pcie-phy.yaml | 95 +++++++++++++++++++
> 1 file changed, 95 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml
>
> diff --git a/Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml b/Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml
> new file mode 100644
> index 000000000000..b9f89e343b0b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml
> @@ -0,0 +1,95 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/phy/fsl,imx8-pcie-phy.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale i.MX8 SoC series PCIe PHY Device Tree Bindings
> +
> +maintainers:
> + - Richard Zhu <hongxing.zhu@xxxxxxx>
> +
> +properties:
> + "#phy-cells":
> + const: 0
> +
> + compatible:
> + enum:
> + - fsl,imx8mm-pcie-phy
> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: PHY module clock

The description doesn't really add much. Just 'maxItems: 1'.

> +
> + clock-names:
> + items:
> + - const: ref
> +
> + resets:
> + items:
> + - description: Phandles to PCIe-related reset lines exposed by SRC
> + IP block.

More than 1 phandle? The schema says only 1. Again, for only 1, you can
use just 'maxItems: 1'.

> +
> + reset-names:
> + items:
> + - const: pciephy
> +
> + fsl,refclk-pad-mode:
> + description: |
> + Specifies the mode of the refclk pad used. It can be UNUSED(PHY
> + refclock is derived from SoC internal source), INPUT(PHY refclock
> + is provided externally via the refclk pad) or OUTPUT(PHY refclock
> + is derived from SoC internal source and provided on the refclk pad).
> + Refer include/dt-bindings/phy/phy-imx8-pcie.h for the constants
> + to be used.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [ 0, 1, 2 ]
> +
> + fsl,tx-deemph-gen1:
> + description: Gen1 De-emphasis value (optional required).

Optional or required?

> + $ref: /schemas/types.yaml#/definitions/uint32
> + default: 0
> +
> + fsl,tx-deemph-gen2:
> + description: Gen2 De-emphasis value (optional required).
> + $ref: /schemas/types.yaml#/definitions/uint32
> + default: 0
> +
> + fsl,clkreq-unsupported:
> + type: boolean
> + description: A boolean property indicating the CLKREQ# signal is
> + not supported in the board design (optional)
> +
> +required:
> + - "#phy-cells"
> + - compatible
> + - reg
> + - clocks
> + - clock-names
> + - fsl,refclk-pad-mode
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/imx8mm-clock.h>
> + #include <dt-bindings/phy/phy-imx8-pcie.h>
> + #include <dt-bindings/reset/imx8mq-reset.h>
> +
> + pcie_phy: pcie-phy@32f00000 {
> + compatible = "fsl,imx8mm-pcie-phy";
> + reg = <0x32f00000 0x10000>;
> + clocks = <&clk IMX8MM_CLK_PCIE1_PHY>;
> + clock-names = "ref";
> + assigned-clocks = <&clk IMX8MM_CLK_PCIE1_PHY>;
> + assigned-clock-rates = <100000000>;
> + assigned-clock-parents = <&clk IMX8MM_SYS_PLL2_100M>;
> + resets = <&src IMX8MQ_RESET_PCIEPHY>;
> + reset-names = "pciephy";
> + fsl,refclk-pad-mode = <IMX8_PCIE_REFCLK_PAD_INPUT>;
> + #phy-cells = <0>;
> + };
> +...
> --
> 2.25.1
>
>