RE: [PATCH v2 01/11] dt-bindings: phy: renesas: Document RZ/G2L USB PHY Control bindings

[Biju Das <biju.das.jz@bp.renesas.com>]

Hi Rob,

> Subject: RE: [PATCH v2 01/11] dt-bindings: phy: renesas: Document RZ/G2L
> USB PHY Control bindings
> 
> Hi Rob,
> 
> Thanks for the feedback.
> 
> > Subject: Re: [PATCH v2 01/11] dt-bindings: phy: renesas: Document
> > RZ/G2L USB PHY Control bindings
> >
> > On Wed, Jun 23, 2021 at 7:38 AM Biju Das <biju.das.jz@bp.renesas.com>
> > wrote:
> > >
> > > Hi Rob,
> > >
> > > Thanks for the feedback.
> > >
> > > > Subject: Re: [PATCH v2 01/11] dt-bindings: phy: renesas: Document
> > > > RZ/G2L USB PHY Control bindings
> > > >
> > > > On Mon, Jun 21, 2021 at 10:39:33AM +0100, Biju Das wrote:
> > > > > Add device tree binding document for RZ/G2L USB PHY control
> driver.
> > > > >
> > > > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > > > > Reviewed-by: Lad Prabhakar
> > > > > <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > > > ---
> > > > > V1->V2:
> > > > >  * Add clock properties
> > > > > ---
> > > > >  .../phy/renesas,rzg2l-usbphyctrl.yaml         | 65
> > +++++++++++++++++++
> > > > >  1 file changed, 65 insertions(+)  create mode 100644
> > > > > Documentation/devicetree/bindings/phy/renesas,rzg2l-usbphyctrl.y
> > > > > am
> > > > > l
> > > > >
> > > > > diff --git
> > > > > a/Documentation/devicetree/bindings/phy/renesas,rzg2l-usbphyctrl
> > > > > .y
> > > > > aml
> > > > > b/Documentation/devicetree/bindings/phy/renesas,rzg2l-usbphyctrl
> > > > > .y
> > > > > aml
> > > > > new file mode 100644
> > > > > index 000000000000..8e8ba43f595d
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/phy/renesas,rzg2l-usbphy
> > > > > +++ ct
> > > > > +++ rl.y
> > > > > +++ aml
> > > > > @@ -0,0 +1,65 @@
> > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML
> > > > > +1.2
> > > > > +---
> > > > > +$id:
> > > > > +https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%
> > > > > +2F
> > > > > +devi
> > > > > +cetree.org%2Fschemas%2Fphy%2Frenesas%2Crzg2l-usbphyctrl.yaml%23
> > > > > +&a
> > > > > +mp;d
> > > > > +ata=04%7C01%7Cbiju.das.jz%40bp.renesas.com%7Cc6bbf5f6ce334eaa72
> > > > > +2a
> > > > > +08d9
> > > > > +359f07ad%7C53d82571da1947e49cb4625a166a4a2a%7C0%7C0%7C637599779
> > > > > +42
> > > > > +1910
> > > > > +039%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzI
> > > > > +iL
> > > > > +CJBT
> > > > > +iI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=Jcf6Om4DehifCe1KO1rm
> > > > > +t5
> > > > > +LxTB
> > > > > +6jtGoQLD1MoqWGM%2F0%3D&amp;reserved=0
> > > > > +$schema:
> > > > > +https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%
> > > > > +2F
> > > > > +devi
> > > > > +cetree.org%2Fmeta-
> > schemas%2Fcore.yaml%23&amp;data=04%7C01%7Cbiju.das.
> > > > > +jz%40bp.renesas.com%7Cc6bbf5f6ce334eaa722a08d9359f07ad%7C53d825
> > > > > +71
> > > > > +da19
> > > > > +47e49cb4625a166a4a2a%7C0%7C0%7C637599779421910039%7CUnknown%7CT
> > > > > +WF
> > > > > +pbGZ
> > > > > +sb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVC
> > > > > +I6
> > > > > +Mn0%
> > > > > +3D%7C1000&amp;sdata=LlqPRLf9%2BGrEdSapxCFhwxVKcXTVh9ECr%2FXPN0S
> > > > > +Iz
> > > > > +i4%3
> > > > > +D&amp;reserved=0
> > > > > +
> > > > > +title: Renesas RZ/G2L USB2.0 PHY Control
> > > > > +
> > > > > +maintainers:
> > > > > +  - Biju Das <biju.das.jz@bp.renesas.com>
> > > > > +
> > > > > +description:
> > > > > +  The RZ/G2L USB2.0 PHY Control mainly controls reset and power
> > > > > +down of the
> > > > > +  USB/PHY.
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    items:
> > > > > +      - enum:
> > > > > +          - renesas,r9a07g044-usbphyctrl # RZ/G2{L,LC}
> > > > > +      - const: renesas,rzg2l-usbphyctrl
> > > > > +
> > > > > +  reg:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  clocks:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  resets:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  power-domains:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  '#phy-cells':
> > > > > +    # see phy-bindings.txt in the same directory
> > > > > +    const: 1
> > > > > +    description: |
> > > > > +      The phandle's argument in the PHY specifier is the phy
> > > > > + reset
> > > > control bit
> > > > > +      of usb phy control.
> > > > > +      0 = Port 1 Phy reset
> > > > > +      1 = Port 2 Phy reset
> > > > > +    enum: [ 0, 1 ]
> > > >
> > > > You already have the const, so this doesn't do anything.
> > >
> > > OK, will take out const.
> >
> > No, 'const' is correct. This is the value of '#phy-cells', not the
> > contents (we don't have a way to express schema for that).
> 
> OK.
> 
> >
> > > > > +required:
> > > > > +  - compatible
> > > > > +  - reg
> > > > > +  - clocks
> > > > > +  - '#phy-cells'
> > > > > +
> > > > > +additionalProperties: false
> > > > > +
> > > > > +examples:
> > > > > +  - |
> > > > > +    #include <dt-bindings/clock/r9a07g044-cpg.h>
> > > > > +
> > > > > +    usbphyctrl@11c40000 {
> > > >
> > > > usb-phy@...
> > >
> > > The IP is called USBPHY control. It mainly controls reset and power
> > > down
> > of the USB2.0/PHY.
> >
> > Sounds like it should be using the reset binding...

OK, Will model this as a reset binding. Since the IP mainly controls reset and power down
Of the USB2.0/PHY. So it is better to have reset binding.

Regards,
Biju

> This IP has reset, clock control , connection control , clock status and
> power down setting registers.
> Currenty we are using reset registers for turning ON USB/PHY block.
> 
> Since it has extra registers I thought of modelling it as a phy device.
> But we could model as reset device as well.
> But it has extra functionalities apart from reset.
> 
> So what do you propose here? Model as a reset device or phy device since
> it is related to phy?
> Please share your opinion on this.
> 
> Regards,
> Biju
> 
> > >
> > > So not sure usb-phy is right one here ? I prefer usb-phy-ctrl instead.
> > Is it ok? Please let me know.
> >
> > A node with #phy-cells should use the standard phy node names unless
> > it has other controls.
> 
> Apart from reset, it has other controls like  clock control , connection
> control , clock status and powerdown setting registers.
> 
> Cheers,
> Biju
> 
> As I said, this doesn't seem to be a phy, so using
> > #phy-cells here is what seems wrong.
> >
> > > > > +        compatible = "renesas,r9a07g044-usbphyctrl",
> > > > > +                     "renesas,rzg2l-usbphyctrl";
> > > > > +        reg = <0x11c40000 0x10000>;
> > > > > +        clocks = <&cpg CPG_MOD R9A07G044_USB_PCLK>;
> > > > > +        resets = <&cpg R9A07G044_USB_PCLK>;
> > > > > +        power-domains = <&cpg>;
> >
> > Also, are these all resources of the usbphyctrl block and not just
> > resources you happen to want in the driver? For example, the
> > power-domain should be the power island that this block resides in.
> >
> > > > > +        #phy-cells = <1>;
> > > > > +    };
> > > > > --
> > > > > 2.17.1
> > > > >
> > > > >