Re: [PATCH v3 2/2] phy: zynqmp: Add dt bindings for ZynqMP phy

[Rob Herring <robh@kernel.org>]

On Wed, Sep 05, 2018 at 10:12:27PM +0530, Anurag Kumar Vulisha wrote:
> This patch adds the document describing dt bindings for ZynqMP
> phy. ZynqMP SOC has a High Speed Processing System Gigabit
> Transceiver which provides PHY capabilties to USB, SATA,
> PCIE, Display Port and Ehernet SGMII controllers.
> 
> Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
> ---
>  Changes in v3:
> 	1. Corrected the Documentation as suggested by Vivek Gautam
> 
>  Changes in v2:
> 	1. None
>  .../devicetree/bindings/phy/phy-zynqmp.txt         | 104 +++++++++++++++++++++
>  1 file changed, 104 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/phy/phy-zynqmp.txt
> 
> diff --git a/Documentation/devicetree/bindings/phy/phy-zynqmp.txt b/Documentation/devicetree/bindings/phy/phy-zynqmp.txt
> new file mode 100644
> index 0000000..65007c4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/phy-zynqmp.txt
> @@ -0,0 +1,104 @@
> +Xilinx ZynqMP PHY binding
> +
> +This binding describes a ZynqMP PHY device that is used to control ZynqMP
> +High Speed Gigabit Transceiver(GT). ZynqMP PS GTR provides four lanes
> +and are used by USB, SATA, PCIE, Display port and Ethernet SGMMI controllers.
> +
> +Phy provider node
> +=================
> +
> +Required properties:
> +- compatible	: Can be "xlnx,zynqmp-psgtr-v1.1" or "xlnx,zynqmp-psgtr"
> +
> +- reg           : Address and length of register sets for each device in
> +                  "reg-names"
> +
> +- reg-names     : The names of the register addresses corresponding to the
> +		  registers filled in "reg":
> +			- serdes: SERDES block register set
> +			- siou: SIOU block register set
> +
> +Optional properties:
> +- xlnx,tx_termination_fix : Include this for fixing functional issue with the

s/_/-/

> +		  TX termination resistance in GT, which can be out of spec for
> +		  the XCZU9EG silicon version. This property is not required for
> +		  "xlnx,zynqmp-psgtr-v1.1"
> +
> +Required nodes	:  A sub-node is required for each lane the controller
> +		   provides.
> +
> +Phy sub-nodes
> +=============
> +
> +Required properties:
> +lane0:

lane0 or lane@0? If you need or care about numbering then add a reg 
property.

> +- #phy-cells	: Should be 4
> +
> +lane1:
> +- #phy-cells	: Should be 4
> +
> +lane2:
> +- #phy-cells	: Should be 4
> +
> +lane3:
> +- #phy-cells	: Should be 4
> +
> +Example:
> +	zynqmp_phy: phy@fd400000 {
> +		compatible = "xlnx,zynqmp-psgtr-v1.1";
> +		status = "okay";
> +		reg = <0x0 0xfd400000 0x0 0x40000>, <0x0 0xfd3d0000 0x0 0x1000>;
> +		reg-names = "serdes", "siou";
> +
> +		lane0: lane@0 {
> +			#phy-cells = <4>;
> +		};
> +		lane1: lane@1 {
> +			#phy-cells = <4>;
> +		};
> +		lane2: lane@2 {
> +			#phy-cells = <4>;
> +		};
> +		lane3: lane@3 {
> +			#phy-cells = <4>;
> +		};
> +	};
> +
> +Specifying phy control of devices
> +=================================
> +
> +Device nodes should specify the configuration required in their "phys"
> +property, containing a phandle to the phy port node and a device type.
> +
> +phys = <PHANDLE CONTROLLER_TYPE CONTROLLER_INSTANCE LANE_NUM LANE_FREQ>;
> +
> +PHANDLE                 = &lane0 or &lane1 or &lane2 or &lane3
> +CONTROLLER_TYPE         = PHY_TYPE_PCIE or PHY_TYPE_SATA or PHY_TYPE_USB
> +			  or PHY_TYPE_DP or PHY_TYPE_SGMII
> +CONTROLLER_INSTANCE     = Depends on controller type used, can be any of
> +				PHY_TYPE_PCIE : 0 or 1 or 2 or 3
> +				PHY_TYPE_SATA : 0 or 1
> +				PHY_TYPE_USB  : 0 or 1
> +				PHY_TYPE_DP   : 0 or 1
> +				PHY_TYPE_SGMII: 0 or 1 or 2 or 3
> +LANE_NUM                = Depends on which lane clock is used as ref clk, can be
> +			  0 or 1 or 2 or 3

I'm not really clear about what this is.

> +LANE_FREQ               = Frequency that controller can operate, can be any of
> +			  19.2Mhz,20Mhz,24Mhz,26Mhz,27Mhz,28.4Mhz,40Mhz,52Mhz,
> +			  100Mhz,108Mhz,125Mhz,135Mhz,150Mhz

This can't be implied by the mode/type? I wouldn't expect any frequency 
can be used for each mode.

> +
> +Example:
> +
> +#include <dt-bindings/phy/phy.h>
> +
> +	usb@fe200000 {
> +		...
> +		phys	  = <&lane2 PHY_TYPE_USB3 0 2 2600000>;
> +		...
> +	};
> +
> +	ahci@fd0c0000 {
> +		...
> +		phys	  = <&lane3 PHY_TYPE_SATA 1 1 125000000>;
> +		...
> +	};

What if you are doing multiple lanes for 1 device? That would be more 
useful 2nd example if that's supported.

> -- 
> 2.1.1
>