Re: [PATCH v2 3/4] dt-bindings: phy: Add support for QMP phy

[Vivek Gautam]

Hi Stephen,

On Tue, Nov 29, 2016 at 4:25 AM, Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote:
> On 11/22, Vivek Gautam wrote:
>> diff --git a/Documentation/devicetree/bindings/phy/qcom-qmp-phy.txt b/Documentation/devicetree/bindings/phy/qcom-qmp-phy.txt
>> new file mode 100644
>> index 0000000..ffb173b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/phy/qcom-qmp-phy.txt
>> @@ -0,0 +1,74 @@
>> +Qualcomm QMP PHY
>> +----------------
>> +
>> +QMP phy controller supports physical layer functionality for a number of
>> +controllers on Qualcomm chipsets, such as, PCIe, UFS, and USB.
>> +
>> +Required properties:
>> + - compatible: compatible list, contains:
>> +            "qcom,msm8996-qmp-pcie-phy" for 14nm PCIe phy on msm8996,
>> +            "qcom,msm8996-qmp-usb3-phy" for 14nm USB3 phy on msm8996.
>> + - reg: list of offset and length pair of the PHY register sets.
>> +     at index 0: offset and length of register set for PHY common
>> +                 serdes block.
>> +     from index 1 - N: offset and length of register set for each lane,
>> +                       for N number of phy lanes (ports).
>> + - lane-offsets: array of offsets to tx, rx and pcs blocks for phy lanes.
>> + - #phy-cells: must be 1
>> +    - Cell after phy phandle should be the port (lane) number.
>> + - clocks: a list of phandles and clock-specifier pairs,
>> +        one for each entry in clock-names.
>> + - clock-names: must be "cfg_ahb" for phy config clock,
>> +                     "aux" for phy aux clock,
>> +                     "ref_clk" for 19.2 MHz ref clk,
>> +                     "ref_clk_src" for reference clock source,
>
> We typically leave "clk" out of clk names because it's redundant.
>
>> +                     "pipe<port-number>" for pipe clock specific to
>> +                     each port/lane (Optional).
>
> The pipe clocks are orphaned right now. We should add an output
> clock from the phy to go into the controller and back into the
> phy if I recall correctly. The phy should be a clock provider
> itself so it can output the pipe clock source into GCC and back
> into the phy and controller.

You are correct. The pipe clocks come out of PHY controllers and
go back to the gcc that gates them finally.

I will register the phy drivers as clock providers so that gcc can make
reference to it.


Best Regards
Vivek

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