Re: [PATCH v3 1/3] dt-bindings: phy: Add Stingray USB PHY binding document

From: Srinath Mannam
Date: Mon Feb 18 2019 - 22:39:19 EST


Hi Rob,

Thanks for review, please see my comments below inline.

On Mon, Feb 18, 2019 at 10:52 PM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Wed, Feb 06, 2019 at 11:02:25PM +0530, Srinath Mannam wrote:
> > Add DT binding document for Stingray USB PHY.
> >
> > Signed-off-by: Srinath Mannam <srinath.mannam@xxxxxxxxxxxx>
> > Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> > Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
> > ---
> > .../bindings/phy/brcm,stingray-usb-phy.txt | 62 ++++++++++++++++++++++
> > 1 file changed, 62 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/phy/brcm,stingray-usb-phy.txt
> >
> > diff --git a/Documentation/devicetree/bindings/phy/brcm,stingray-usb-phy.txt b/Documentation/devicetree/bindings/phy/brcm,stingray-usb-phy.txt
> > new file mode 100644
> > index 0000000..bfe1367
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/brcm,stingray-usb-phy.txt
> > @@ -0,0 +1,62 @@
> > +Broadcom Stingray USB PHY
> > +
> > +Required properties:
> > + - compatible : should be one of the listed compatibles
> > + - "brcm,sr-usb-phy"
> > + - "brcm,sr-usb-phy-v2"
>
> SoC specific compatibles are preferred. Version numbers can be used but
> should follow some documented scheme and be meaningful. What we don't
> want is just Linux developers making up numbering.
>
Both versions are different phy controllers and also have separate
register offsets.
I will provide more meaningful compatible IDs and their documentation
in next patchset.
> > + - reg: offset and length of the PHY blocks registers
> > + - address-cells: should be 1
> > + - size-cells: should be 0
> > +
> > +Sub-nodes:
> > + Each port's PHY should be represented as a sub-node.
> > +
> > +Sub-nodes required properties:
> > + - reg: required for brcm,sr-usb-phy model phy.
> > + reg value 0 is HS phy and 1 is SS phy.
> > + - phy-cells: generic PHY binding; must be 0
> > +
> > +Refer to phy/phy-bindings.txt for the generic PHY binding properties
> > +
> > +Example:
> > + usbphy0: usb-phy@0 {
> > + compatible = "brcm,sr-usb-phy";
> > + reg = <0x00000000 0x100>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + usb0_phy0: phy@0 {
> > + reg = <0>;
> > + #phy-cells = <0>;
>
> Unless there's DT resources for each child node, you don't need these.
> Just make #phy-cells 1 in the parent.
With the use of phy-cell, PHY argument is available with xlate
function, But controller specific assignments required
to be done while probe. So I will take your first option given in
previous comment.

Regards,
Srinath.
>
> Rob