Re: [PATCH v2 5/5] usb: dwc3: rockchip: add devicetree bindings documentation

[William Wu <william.wu@rock-chips.com>]

Hi Felipe,

On 05/24/2016 05:32 PM, Felipe Balbi wrote:
> Hi,
>
> William Wu <william.wu@rock-chips.com> writes:
>> This patch documents the device tree documentation required for
>> Rockchip USB3.0 core wrapper consist of USB3.0 IP from Synopsys.
>>
>> It could operate in device mode (SS, HS, FS) and host
>> mode (SS, HS, FS, LS).
>>
>> Signed-off-by: William Wu <william.wu@rock-chips.com>
>> ---
>> Changes in v2:
>> - add rockchip,dwc3.txt to Documentation/devicetree/bindings/ (Felipe, Brian)
>>
>>   .../devicetree/bindings/usb/rockchip,dwc3.txt      | 45 ++++++++++++++++++++++
>>   1 file changed, 45 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/usb/rockchip,dwc3.txt
>>
>> diff --git a/Documentation/devicetree/bindings/usb/rockchip,dwc3.txt b/Documentation/devicetree/bindings/usb/rockchip,dwc3.txt
>> new file mode 100644
>> index 0000000..10303d9
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/usb/rockchip,dwc3.txt
>> @@ -0,0 +1,45 @@
>> +Rockchip SuperSpeed DWC3 USB SoC controller
>> +
>> +Required properties:
>> +- compatible:	should contain "rockchip,dwc3"
>> +- clocks:		A list of phandle + clock-specifier pairs for the
>> +				clocks listed in clock-names
>> +- clock-names:	Should contain the following:
>> +  "clk_usb3otg0_ref"	Controller reference clk
>> +  "clk_usb3otg0_suspend"Controller suspend clk, can use 24 MHz or 32 KHz
>> +  "aclk_usb3"		Master/Core clock, have to be >= 62.5 MHz for SS operation
>> +
>> +
>> +Optional clocks:
>> +  "aclk_usb3otg0"	Aclk for specific usb controller clock.
>> +  "aclk_usb3_rksoc_axi_perf"  USB AXI perf clock.  Not present on all platforms.
>> +  "aclk_usb3_grf"	USB grf clock.  Not present on all platforms.
>> +
>> +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:
>> +
>> +Example device nodes:
>> +
>> +	usbdrd3_0: usb@fe800000 {
>> +
> no reg property?
For now, we don't need reg property here. Because we only need to do
enable some clocks and populate its children in 
drivers/usb/dwc3/dwc3-of-simple.c.
And it's similar to arch/arm/boot/dts/exynos5420.dtsi usbdrd3_0 node.
> 		compatible = "rockchip,dwc3";
>> +		clocks = <&cru SCLK_USB3OTG0_REF>, <&cru SCLK_USB3OTG0_SUSPEND>,
>> +			 <&cru ACLK_USB3>, <&cru ACLK_USB3OTG0>,
>> +			 <&cru ACLK_USB3_RKSOC_AXI_PERF>, <&cru ACLK_USB3_GRF>;
>> +		clock-names = "clk_usb3otg0_ref", "clk_usb3otg0_suspend",
>> +			      "aclk_usb3", "aclk_usb3otg0",
>> +			      "aclk_usb3_rksoc_axi_perf", "aclk_usb3_grf";
>> +		#address-cells = <2>;
>> +		#size-cells = <2>;
>> +		ranges;
>> +		status = "disabled";
>> +		usbdrd_dwc3_0: dwc3 {
> no address here?
I think here don't  necessarily need address. The child node dwc3 can 
inherit address from the parent node.
And with this dtsi patch, the dev path show as follows:
/sys/devices/platform/usb@fe800000/fe800000.dwc3

Is it need for coding style or other reason?

>
>> +			compatible = "snps,dwc3";
>> +			reg = <0x0 0xfe800000 0x0 0x100000>;
>> +			interrupts = <GIC_SPI 105 IRQ_TYPE_LEVEL_HIGH>;
>> +			dr_mode = "otg";
>> +			status = "disabled";
>> +		};
>> +	};
>> -- 
>> 1.9.1
>>
>>
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