Re: [RFC PATCH v2 1/2] dt-bindings: phy: Document cadence Sierra PHY bindings

From: Rob Herring
Date: Tue Sep 25 2018 - 17:02:00 EST


On Thu, Sep 06, 2018 at 03:42:29PM +0100, Alan Douglas wrote:
> Add DT binding documentation for Sierra PHY. The PHY supports
> a number of different protocols, including PCIe and USB.
>
> The PHY lanes may be configured as single or multi-lane links.
> Each link is treated as a separate subnode. For example, if
> there are 4 lanes in total the first 2 may be configured as
> a multi-lane PCIe link while the other two are single lane
> USB links, and in this case there would be 3 subnodes.
>
> There are two resets for the PHY block, and additional resets,
> one for each lane. For multi-lane links, only the reset for
> the master lane is required, the resets on other lanes have no
> effect.
>
> Signed-off-by: Alan Douglas <adouglas@xxxxxxxxxxx>
> ---
> .../devicetree/bindings/phy/cdns-sierra-phy.txt | 65 ++++++++++++++++++++++
> 1 file changed, 65 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/phy/cdns-sierra-phy.txt
>
> diff --git a/Documentation/devicetree/bindings/phy/cdns-sierra-phy.txt b/Documentation/devicetree/bindings/phy/cdns-sierra-phy.txt
> new file mode 100644
> index 0000000..94a8a7f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/cdns-sierra-phy.txt
> @@ -0,0 +1,65 @@
> +Cadence Sierra PHY
> +-----------------------
> +
> +Required properties:
> +- compatible: cdns,sierra-phy-t0
> +- clocks: Must contain an entry in clock-names.
> + See ../clocks/clock-bindings.txt for details.
> +- clock-names: Must be "phy_clk"
> +- resets: Must contain an entry for each in reset-names.
> + See ../reset/reset.txt for details.
> +- reset-names: Must include "sierra_reset" and "sierra_apb" and one for each
> + sub-node.
> + "sierra_reset" must control the reset line to the PHY.
> + "sierra_apb" must control the reset line to the APB PHY
> + interface.
> + Resets for each subnode must control the master lane for the
> + subnode lane group.

What are the names?

> +- reg: register range for the PHY.
> +- reg-names: Must be "reg".

Kind of pointless with only 1.

> +- #address-cells: Should be 1
> +- #size-cells: Should be 0
> +
> +Optional properties:
> +- cdns,autoconf: If present, indicates that the PHY registers will
> + be configured by hardware. If not present, all
> + sub-node optional properties must be provided.

boolean?

> +
> +Sub-nodes:
> + Each group of PHY lanes with a single master lane should be represented as
> + a sub-node. Note that the actual configuration of each lane is determined by
> + hardware strapping, and must match the configuration specified here.
> +
> +Sub-node required properties:
> +- #phy-cells: Generic PHY binding; must be 0.
> +
> +Sub-node optional properties:
> +- reg: The master lane number.
> +- cdns,num-lanes: Number of lanes in this group. From 1 to 4.
> +- cdns,phy-type: Can be PHY_TYPE_PCIE or PHY_TYPE_USB3, depending on
> + configuration of lanes.
> +
> +Example:
> + pcie_phy4: pcie-phy4@fd240000 {

pcie-phy@fd240000

> + compatible = "cdns,sierra-phy-t0";
> + reg = <0x0 0xfd240000 0x0 0x40000>;
> + reg-names = "reg";
> + resets = <&phyrst 0>, <&phyrst 1>,<&phyrst 2>,<&phyrst 4>;
> + reset-names = "sierra_reset","sierra_apb","pcie_phy0",pcie_phy1;

spaces and quotes missing.

> + clocks = <&phyclock>;
> + clock-names = "phy_clk";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + pcie0_phy0: pcie-phy0@0 {

pcie-phy@0

> + reg = <0>;
> + cdns,num-lanes = <2>;
> + #phy-cells = <0>;
> + cdns,phy-type = <PHY_TYPE_PCIE>;
> + };
> + pcie0_phy1: pcie-phy1@0 {

pcie-phy@2

Or reg should be 1?

> + reg = <2>;
> + cdns,num-lanes = <1>;
> + #phy-cells = <0>;
> + cdns,phy-type = <PHY_TYPE_PCIE>;
> + };
> +
> --
> 1.9.0
>