Re: [PATCH 4/8] dt-bindings: usb: dwc3: Add Amlogic G12A DWC3 Glue Bindings

[Rob Herring <robh@kernel.org>]

On Tue, Feb 12, 2019 at 04:14:09PM +0100, Neil Armstrong wrote:
> Adds the bindings for the Amlogic G12A USB Glue HW.
> 
> The Amlogic G12A SoC Family embeds 2 USB Controllers :
> - a DWC3 IP configured as Host for USB2 and USB3
> - a DWC2 IP configured as Peripheral USB2 Only
> 
> A glue connects these both controllers to 2 USB2 PHYs,
> and optionnally to an USB3+PCIE Combo PHY shared with the PCIE controller.
> 
> The Glue configures the UTMI 8bit interfaces for the USB2 PHYs, including
> routing of the OTG PHY between the DWC3 and DWC2 controllers, and
> setups the on-chip OTG mode selection for this PHY.
> 
> The PHYs are children of the Glue node since the Glue controls the interface
> with the PHY, not the DWC3 controller.
> 
> The PHY interconnect is handled into ports subnodes, which eases describing
> which PHY is enabled (like the USB3 shared PHY) and futures layouts on
> derivatives of the G12A Family.
> 
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  .../devicetree/bindings/usb/amlogic,dwc3.txt  | 109 ++++++++++++++++++
>  1 file changed, 109 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/amlogic,dwc3.txt b/Documentation/devicetree/bindings/usb/amlogic,dwc3.txt
> index 9a8b631904fd..c7c4726ef10d 100644
> --- a/Documentation/devicetree/bindings/usb/amlogic,dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/amlogic,dwc3.txt
> @@ -40,3 +40,112 @@ Example device nodes:
>  				phy-names = "usb2-phy", "usb3-phy";
>  			};
>  		};
> +
> +Amlogic Meson G12A DWC3 USB SoC Controller Glue
> +
> +The Amlogic G12A embeds a DWC3 USB IP Core configured for USB2 and USB3
> +in host-only mode, and a DWC2 IP Core configured for USB2 peripheral mode
> +only.
> +
> +A glue connects the DWC3 core to USB2 PHYs and optionnaly to an USB3 PHY.
> +
> +One of the USB2 PHY can be re-routed in peripheral mode to a DWC2 USB IP.
> +
> +The DWC3 Glue controls the PHY routing and power, an interrupt line is
> +connected to the Glue to serve as OTG ID change detection.
> +
> +Required properties:
> +- compatible:	Should be "amlogic,meson-g12a-usb-ctrl"
> +- clocks:	a handle for the "USB" clock
> +- clock-names:	must be "usb"
> +- resets:	a handle for the shared "USB" reset line
> +- reset-names:	must be "usb"

-name for a single entry is pointless.

> +- reg:		The base address and length of the registers
> +- interrupts:	the interrupt specifier for the OTG detection
> +
> +Required child nodes:
> +
> +USB Ports are described as child 'port' nodes grouped under a 'ports' node,
> +with #address-cells, #size-cells specified.
> +
> +Each 'port' sub-node identifies a possible USB Port served by an USB PHY
> +identified by the 'phy' property as decribed in ../phy/phy-bindings.txt
> +
> +Each 'port' is identified by a reg property to number the port.
> +
> +The following table lists for each supported model the port number
> +corresponding to each PHY serving a physical USB Port.
> +
> + Family	   Port 0     Port 1    Port 2    Port 3    Port 4
> +---------------------------------------------------------------
> + G12A	   USBHOST_A  USBOTG_B  Reserved  Reserved  USB3_0
> +
> +A child node must exist to represent the core DWC3 IP block. The name of
> +the node is not important. The content of the node is defined in dwc3.txt.
> +
> +A child node must exist to represent the core DWC2 IP block. The name of
> +the node is not important. The content of the node is defined in dwc2.txt.
> +
> +PHY documentation is provided in the following places:
> +- Documentation/devicetree/bindings/phy/meson-g12a-usb2-phy.txt
> +- Documentation/devicetree/bindings/phy/meson-g12a-usb3-pcie-phy.txt
> +
> +
> +Example device nodes:
> +	usb: usb@ffe09000 {
> +			compatible = "amlogic,meson-g12a-usb-ctrl";
> +			reg = <0x0 0xffe09000 0x0 0xa0>;
> +			interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>;
> +			#address-cells = <2>;
> +			#size-cells = <2>;
> +			ranges;
> +
> +			clocks = <&clkc CLKID_USB>;
> +			clock-names = "usb";
> +			resets = <&reset RESET_USB>;
> +			reset-names = "usb";
> +
> +			ports {
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +
> +				/* USB2 Port 0 */
> +				usb20: port@0 {
> +					reg = <0>;
> +					phys = <&usb2_phy0>;

'ports' and 'port' are reserved for the graph binding. Don't use it for 
your own thing.

Can't you just make 'phys' a list using 0 phandle if you need to skip 
entries.

> +				};
> +
> +				/* USB2 Port 1 */
> +				usb21: port@1 {
> +					reg = <1>;
> +					phys = <&usb2_phy1>;
> +				};
> +
> +				/* USB3 Port 0 */
> +				usb3: port@4 {
> +					reg = <4>;
> +					phys = <&usb3_pcie_phy PHY_TYPE_USB3>;
> +				};
> +			};
> +
> +			dwc2: usb@ff400000 {
> +				compatible = "amlogic,meson-g12a-usb", "snps,dwc2";
> +				reg = <0x0 0xff400000 0x0 0x40000>;
> +				interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
> +				clocks = <&clkc CLKID_USB1_DDR_BRIDGE>;
> +				clock-names = "ddr";
> +				dr_mode = "peripheral";
> +				g-rx-fifo-size = <192>;
> +				g-np-tx-fifo-size = <128>;
> +				g-tx-fifo-size = <128 128 16 16 16>;
> +			};
> +
> +			dwc3: dwc3@ff500000 {

usb@... or usb3@...

> +				compatible = "snps,dwc3";
> +				reg = <0x0 0xff500000 0x0 0x100000>;
> +				interrupts = <GIC_SPI 30 IRQ_TYPE_LEVEL_HIGH>;
> +				dr_mode = "host";
> +				snps,dis_u2_susphy_quirk;
> +				snps,quirk-frame-length-adjustment;
> +			};
> +	};
> -- 
> 2.20.1
>