RE: [PATCH v2 2/4] dt-bindings: phy: add imx8 pcie phy driver support

[Richard Zhu <hongxing.zhu@nxp.com>]

> -----Original Message-----
> From: Lucas Stach <l.stach@pengutronix.de>
> Sent: Monday, September 27, 2021 4:33 PM
> To: Richard Zhu <hongxing.zhu@nxp.com>; kishon@ti.com; vkoul@kernel.org;
> robh@kernel.org; galak@kernel.crashing.org; shawnguo@kernel.org
> Cc: linux-phy@lists.infradead.org; devicetree@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
> kernel@pengutronix.de; dl-linux-imx <linux-imx@nxp.com>
> Subject: Re: [PATCH v2 2/4] dt-bindings: phy: add imx8 pcie phy driver support
> 
> Am Sonntag, dem 26.09.2021 um 15:39 +0800 schrieb Richard Zhu:
> > Add dt-binding for the standalone i.MX8 PCIe PHY driver.
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > ---
> >  .../bindings/phy/fsl,imx8-pcie-phy.yaml       | 67
> +++++++++++++++++++
> >  1 file changed, 67 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml
> > b/Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml
> > new file mode 100644
> > index 000000000000..fd08897fef82
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/fsl,imx8-pcie-phy.yaml
> > @@ -0,0 +1,67 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id:
> > +https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevi
> >
> +cetree.org%2Fschemas%2Fphy%2Ffsl%2Cimx8-pcie-phy.yaml%23&amp;dat
> a=04%
> >
> +7C01%7Chongxing.zhu%40nxp.com%7C7c5f7203447a4c259d9f08d981915ef
> 3%7C68
> >
> +6ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637683283637916778%
> 7CUnknown
> >
> +%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1ha
> WwiLC
> >
> +JXVCI6Mn0%3D%7C1000&amp;sdata=m1S7Si0nL4zveL76S%2FvpKbFFrWhJa
> mFNgcVld
> > +Rxx82I%3D&amp;reserved=0
> > +$schema:
> > +https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevi
> >
> +cetree.org%2Fmeta-schemas%2Fcore.yaml%23&amp;data=04%7C01%7Cho
> ngxing.
> >
> +zhu%40nxp.com%7C7c5f7203447a4c259d9f08d981915ef3%7C686ea1d3bc
> 2b4c6fa9
> >
> +2cd99c5c301635%7C0%7C0%7C637683283637916778%7CUnknown%7CT
> WFpbGZsb3d8e
> >
> +yJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3
> D%7C1
> >
> +000&amp;sdata=S2uWTI603YkF68zqySbkcK32XaPEwU4%2BHuntwR%2Bkx7
> g%3D&amp;
> > +reserved=0
> > +
> > +title: Freescale i.MX8 SoC series PCIe PHY Device Tree Bindings
> > +
> > +maintainers:
> > +  - Richard Zhu <hongxing.zhu@nxp.com>
> > +
> > +properties:
> > +  "#phy-cells":
> > +    const: 0
> > +
> > +  compatible:
> > +    enum:
> > +      - fsl,imx8mm-pcie-phy
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    items:
> > +      - description: PHY module clock
> > +
> > +  clock-names:
> > +    items:
> > +      - const: phy
> 
> The clock name should describe what it is used for in the hardware block
> described by the DT node. So I would think this should be called "ref" or
> something like this, as I believe this clock is really only used as the reference
> clock and can be disabled when the refclock is supplied via the pad, right?
> 
[Richard Zhu] That's right. "ref" is better. Thanks.

> > +
> > +  fsl,refclk-pad-mode:
> > +    description: |
> > +      Specifies the mode of the refclk pad used. It can be NO_USED(PHY
> > +      refclock is derived from SoC internal source), INPUT(PHY refclock
> > +      is provided externally via the refclk pad) or OUTPUT(PHY refclock
> > +      is derived from SoC internal source and provided on the refclk pad).
> > +      Refer include/dt-bindings/phy/phy-imx8-pcie.h for the constants
> > +      to be used.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    enum: [ 0, 1, 2 ]
> > +
> > +required:
> > +  - "#phy-cells"
> > +  - compatible
> > +  - reg
> > +  - clocks
> > +  - clock-names
> > +  - fsl,refclk-pad-mode
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/imx8mm-clock.h>
> > +
> > +    pcie_phy: pcie-phy@32f00000 {
> > +            compatible = "fsl,imx8mm-pcie-phy";
> > +            reg = <0x32f00000 0x10000>;
> > +            clocks = <&clk IMX8MM_CLK_PCIE1_PHY>;
> > +            clock-names = "phy";
> > +            assigned-clocks = <&clk IMX8MM_CLK_PCIE1_PHY>;
> > +            assigned-clock-rates = <100000000>;
> > +            assigned-clock-parents = <&clk
> IMX8MM_SYS_PLL2_100M>;
> > +            fsl,refclk-pad-mode = <1>;
> 
> Include the new header added in patch 1 and use the enum.
[Richard Zhu] Got that, would changed in next version. Thanks.
> 
> > +            #phy-cells = <0>;
> > +    };
> > +...
>