[PATCH v8 2/5] dt-bindings: phy: Add documentation for Airoha AN7581 USB PHY
Christian Marangi
ansuelsmth at gmail.com
Thu May 21 01:22:27 PDT 2026
On Thu, May 21, 2026 at 09:44:16AM +0200, Krzysztof Kozlowski wrote:
> On Wed, May 20, 2026 at 05:09:07PM +0200, Christian Marangi wrote:
> > Add documentation for Airoha AN7581 USB PHY that describe the USB PHY
> > for the USB controller.
> >
> > Airoha AN7581 SoC support a maximum of 2 USB port. The USB 2.0 mode is
> > always supported. The USB 3.0 mode is optional and depends on the Serdes
> > mode currently configured on the system for the relevant USB port.
> >
> > To correctly calibrate, the USB 2.0 port require correct value in
> > "airoha,usb2-monitor-clk-sel" property. Both the 2 USB 2.0 port permit
> > selecting one of the 4 monitor clock for calibration (internal clock not
> > exposed to the system) but each port have only one of the 4 actually
> > connected in HW hence the correct value needs to be specified in DT
> > based on board and the physical port. Normally it's monitor clock 1 for
> > USB1 and monitor clock 2 for USB2.
> >
> > To correctly setup the Serdes mode attached to the USB 3.0 mode, a phys
> > property is required with the phandle pointing to the correct Serdes port
> > provided by the SCU node.
>
>
> ^^^ here - required but:
>
I think I have to rephrase it. It's required if the USB3 is used/wanted. In
the other case for the USB2 phy is not needed.
I will bettet describe this in commit description and on the phys property
description.
> > + phys:
> > + items:
> > + - description: phandle to Serdes PHY
> > +
> > + '#phy-cells':
> > + description: The cell contains the mode, PHY_TYPE_USB2 or PHY_TYPE_USB3,
> > + as defined in dt-bindings/phy/phy.h.
> > + const: 1
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - airoha,usb2-monitor-clk-sel
>
> 'phys' is not required? I think you need it to configure the serdes
> correctly, no?
>
> > + - '#phy-cells'
> > +
> > +additionalProperties: false
>
> Best regards,
> Krzysztof
>
--
Ansuel
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