Re: [PATCH v2 1/2] dt-bindings: phy: Add Sophgo CV1800 USB phy

[Conor Dooley <conor@kernel.org>]

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On Wed, May 01, 2024 at 08:28:47AM +0800, Inochi Amaoto wrote:
> On Tue, Apr 30, 2024 at 06:09:20PM GMT, Conor Dooley wrote:
> > On Mon, Apr 29, 2024 at 08:31:11AM +0800, Inochi Amaoto wrote:
> > > The USB phy of Sophgo CV18XX series SoC needs to sense a pin called
> > > "VBUS_DET" to get the right operation mode. If this pin is not
> > > connected, it only supports setting the mode manually.
> > > 
> > > Add USB phy bindings for Sophgo CV18XX/SG200X series SoC.
> > > 
> > > Signed-off-by: Inochi Amaoto <inochiama@outlook.com>
> > > ---
> > >  .../bindings/phy/sophgo,cv1800-usb-phy.yaml   | 68 +++++++++++++++++++
> > >  1 file changed, 68 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/phy/sophgo,cv1800-usb-phy.yaml
> > > 
> > > diff --git a/Documentation/devicetree/bindings/phy/sophgo,cv1800-usb-phy.yaml b/Documentation/devicetree/bindings/phy/sophgo,cv1800-usb-phy.yaml
> > > new file mode 100644
> > > index 000000000000..7e3382c18d44
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/phy/sophgo,cv1800-usb-phy.yaml
> > > @@ -0,0 +1,68 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/phy/sophgo,cv1800-usb-phy.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Sophgo CV18XX/SG200X USB 2.0 PHY
> > > +
> > > +maintainers:
> > > +  - Inochi Amaoto <inochiama@outlook.com>
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: sophgo,cv1800-usb-phy
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  "#phy-cells":
> > > +    const: 0
> > > +
> > > +  clocks:
> > > +    items:
> > > +      - description: PHY clock
> > > +      - description: PHY app clock
> > > +      - description: PHY stb clock
> > > +      - description: PHY lpm clock
> > > +
> > > +  clock-names:
> > > +    items:
> > > +      - const: phy
> > > +      - const: app
> > > +      - const: stb
> > > +      - const: lpm
> > > +
> > > +  vbus_det-gpios:
> > 
> > "vbus_det-gpios" isn't a common property AFAICT, why does it not get a
> > vendor prefix when the other gpios property does?
> > 
> 
> I have seen other binding (such as sunxi phy) uses this property without 
> vendor prefix. So I think it is a common property and don't add perfix 
> for it. But it is OK for me add the vendor prefix, thanks.

I asked yesterday and Krzysztof said:
"gpios just like supplies - no prefixes, I think."
The other phy used a different property (they're not identical), I did
check that yesterday.

> 
> > > +    description: GPIO to the USB OTG VBUS detect pin. This should not be
> > > +      defined if vbus_det pin and switch pin are connected, which may
> > > +      break the VBUS detection.
> > > +    maxItems: 1
> > > +
> > > +  sophgo,switch-gpios:
> > > +    description: GPIO array for the phy to control connected switch. For
> > > +      host mode, the driver will set these GPIOs to low one by one. For
> > > +      device mode, the driver will set these GPIOs to high in reverse
> > > +      order.
> > > +    maxItems: 2
> > 
> > You're still missing the itemised description of what each of the gpios
> > here are - how would I know which order to put the GPIOs in?
> > 
> > Cheers,
> > Conor.
> 
> In most case, the order depends on hardware design. But following the
> guide sophgo provides, it does have an common order. Is it good to add
> this description as a reference guide? If so, I will add it.

If we can say "gpio 1 connects to xyz on the switch" & "gpio 2 connects
to tuv" then it'll be easier to understand how to write the node.

> 
> Regards,
> Inochi
> 
> > 
> > > +
> > > +required:
> > > +  - compatible
> > > +  - "#phy-cells"
> > > +  - clocks
> > > +  - clock-names
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    phy@48 {
> > > +      compatible = "sophgo,cv1800-usb-phy";
> > > +      reg = <0x48 0x4>;
> > > +      #phy-cells = <0>;
> > > +      clocks = <&clk 92>, <&clk 93>,
> > > +               <&clk 94>, <&clk 95>;
> > > +      clock-names = "phy", "app", "stb", "lpm";
> > > +    };
> > > +
> > > +...
> > > --
> > > 2.44.0
> > > 
> 
> 

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