Re: [PATCH v2 1/3] dt-bindings: usb: Update documentation for Qualcomm DWC3 driver

[Rob Herring <robh@kernel.org>]

On Fri, Apr 13, 2018 at 10:21:22PM +0530, Manu Gautam wrote:
> Existing documentation has lot of incorrect information as it
> was originally added for a driver that no longer exists.
> 
> Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
> ---
>  .../devicetree/bindings/usb/qcom,dwc3.txt          | 78 ++++++++++++++++------
>  1 file changed, 57 insertions(+), 21 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/usb/qcom,dwc3.txt b/Documentation/devicetree/bindings/usb/qcom,dwc3.txt
> index bc8a2fa..fdc574a 100644
> --- a/Documentation/devicetree/bindings/usb/qcom,dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/qcom,dwc3.txt
> @@ -1,54 +1,90 @@
>  Qualcomm SuperSpeed DWC3 USB SoC controller
>  
>  Required properties:
> -- compatible:	should contain "qcom,dwc3"
> +- compatible:		should contain "qcom,dwc3"

Needs an SoC specific compatible string.

> +- reg:			offset and length of register set for QSCRATCH wrapper
> +- power-domains:	specifies a phandle to PM domain provider node
>  - clocks:		A list of phandle + clock-specifier pairs for the
>  				clocks listed in clock-names
> -- clock-names:	Should contain the following:
> +- clock-names:		Should contain the following:
>    "core"		Master/Core clock, have to be >= 125 MHz for SS
>  				operation and >= 60MHz for HS operation
> +  "mock_utmi"		Mock utmi clock needed for ITP/SOF generation in
> +				host mode. Its frequency should be 19.2MHz.
> +  "sleep"		Sleep clock, used for wakeup when USB3 core goes
> +				into low power mode (U3).
>  
>  Optional clocks:
>    "iface"		System bus AXI clock.  Not present on all platforms
> -  "sleep"		Sleep clock, used when USB3 core goes into low
> -				power mode (U3).
> +  "cfg_noc"		System Config NOC clock. Not present on all platforms

These need to be specific as to which compatible properties have or 
don't have these clocks.

> +- assigned-clocks:	should be:
> +				MOCK_UTMI_CLK
> +				MASTER_CLK
> +- assigned-clock-rates: should be:
> +                                19.2Mhz (192000000) for MOCK_UTMI_CLK
> +                                >=125Mhz (125000000) for MASTER_CLK in SS mode
> +                                >=60Mhz (60000000) for MASTER_CLK in HS mode
> +
> +Optional properties:
> +- resets:		list of phandle and reset specifier pairs

How many? 

> +- interrupts:		specifies interrupts from controller wrapper used
> +			to wakeup from low power/susepnd state.	Must contain
> +			one or more entry for interrupt-names property
> +- interrupt-names:	Must include the following entries:
> +			- "hs_phy_irq": The interrupt that is asserted when a
> +			   wakeup event is received on USB2 bus
> +			- "ss_phy_irq": The interrupt that is asserted when a
> +			   wakeup event is received on USB3 bus
> +			- "dm_hs_phy_irq" and "dp_hs_phy_irq": Separate
> +			   interrupts for any wakeup event on DM and DP lines

Sounds like the irqs are actually part of the PHYs? If so, then that's 
where they should be in the DT.

> +- qcom,select-utmi-as-pipe-clk: if present, disable USB3 pipe_clk requirement.
> +				Used when dwc3 operates without SSPHY and only
> +				HS/FS/LS modes are supported.
>  
>  Required child node:
>  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.
>  
>  Phy documentation is provided in the following places:
> -Documentation/devicetree/bindings/phy/qcom-dwc3-usb-phy.txt
> +Documentation/devicetree/bindings/phy/qcom-qmp-phy.txt   - USB3 QMP PHY
> +Documentation/devicetree/bindings/phy/qcom-qusb2-phy.txt - USB2 QUSB2 PHY
>  
>  Example device nodes:
>  
>  		hs_phy: phy@100f8800 {
> -			compatible = "qcom,dwc3-hs-usb-phy";
> -			reg = <0x100f8800 0x30>;
> -			clocks = <&gcc USB30_0_UTMI_CLK>;
> -			clock-names = "ref";
> -			#phy-cells = <0>;
> -
> +			compatible = "qcom,qusb2-v2-phy";
> +			...
>  		};
>  
>  		ss_phy: phy@100f8830 {
> -			compatible = "qcom,dwc3-ss-usb-phy";
> -			reg = <0x100f8830 0x30>;
> -			clocks = <&gcc USB30_0_MASTER_CLK>;
> -			clock-names = "ref";
> -			#phy-cells = <0>;
> -
> +			compatible = "qcom,qmp-v3-usb3-phy";
> +			...
>  		};
>  
> -		usb3_0: usb30@0 {
> +		usb3_0: usb30@a6f8800 {
>  			compatible = "qcom,dwc3";
> +			reg = <0xa6f8800 0x400>;
>  			#address-cells = <1>;
>  			#size-cells = <1>;
> -			clocks = <&gcc USB30_0_MASTER_CLK>;
> -			clock-names = "core";
> -
>  			ranges;
>  
> +			interrupts = <0 131 0>, <0 486 0>, <0 488 0>, <0 489 0>;
> +			interrupt-names = "hs_phy_irq", "ss_phy_irq",
> +				  "dm_hs_phy_irq", "dp_hs_phy_irq";
> +
> +			clocks = <&gcc GCC_USB30_PRIM_MASTER_CLK>,
> +				<&gcc GCC_USB30_PRIM_MOCK_UTMI_CLK>,
> +				<&gcc GCC_USB30_PRIM_SLEEP_CLK>;
> +			clock-names = "core", "mock_utmi", "sleep";
> +
> +			assigned-clocks = <&gcc GCC_USB30_PRIM_MOCK_UTMI_CLK>,
> +					  <&gcc GCC_USB30_PRIM_MASTER_CLK>;
> +			assigned-clock-rates = <19200000>, <133000000>;
> +
> +			resets = <&gcc GCC_USB30_PRIM_BCR>;
> +			reset-names = "core_reset";
> +			power-domains = <&gcc USB30_PRIM_GDSC>;
> +			qcom,select-utmi-as-pipe-clk;
>  
>  			dwc3@10000000 {
>  				compatible = "snps,dwc3";
> -- 
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>