Re: [PATCH v2 2/8] dt-bindings: counter: Add new ti,am62-eqep compatible

[Judith Mendez]

Hi David,

On 5/25/24 12:49 PM, David Lechner wrote:
> On 5/24/24 4:44 PM, Judith Mendez wrote:
> > On 5/24/24 3:57 PM, David Lechner wrote:
> > > On 5/24/24 3:50 PM, David Lechner wrote:
> > > > On 5/23/24 6:15 PM, Judith Mendez wrote:
> > > > > Add new compatible ti,am62-eqep for TI K3 devices. If a device
> > > > > uses this compatible, require power-domains property.
> > > > >
> > > > > Since there is only one functional and interface clock for eqep,
> > > > > clock-names is not really required. The clock-name also changed
> > > > > for TI K3 SoCs so make clock-names optional for the new compatible
> > > > > since there is only one clock that is routed to the IP.
> > > > >
> > > > > While we are here, add an example using ti,am62-eqep compatible.
> > > > >
> > > > > Signed-off-by: Judith Mendez <jm@xxxxxx>
> > > > > ---
> > > > > Changes since v1:
> > > > > - Fix eqep binding for new compatible, require
> > > > >    power-domains for new compatible
> > > > > ---
> > > > >    .../devicetree/bindings/counter/ti-eqep.yaml  | 53 +++++++++++++++++--
> > > > >    1 file changed, 48 insertions(+), 5 deletions(-)
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/counter/ti-eqep.yaml b/Documentation/devicetree/bindings/counter/ti-eqep.yaml
> > > > > index 85f1ff83afe72..c4bb0231f166a 100644
> > > > > --- a/Documentation/devicetree/bindings/counter/ti-eqep.yaml
> > > > > +++ b/Documentation/devicetree/bindings/counter/ti-eqep.yaml
> > > > > @@ -11,7 +11,9 @@ maintainers:
> > > > >      properties:
> > > > >      compatible:
> > > > > -    const: ti,am3352-eqep
> > > > > +    enum:
> > > > > +      - ti,am3352-eqep
> > > > > +      - ti,am62-eqep
> > > > >        reg:
> > > > >        maxItems: 1
> > > > > @@ -21,19 +23,43 @@ properties:
> > > > >        maxItems: 1
> > > > >        clocks:
> > > > > -    description: The clock that determines the SYSCLKOUT rate for the eQEP
> > > > > -      peripheral.
> > > > > +    description: The functional and interface clock that determines the clock
> > > > > +      rate for the eQEP peripheral.
> > > > >        maxItems: 1
> > > > >        clock-names:
> > > > > -    const: sysclkout
> > > > > +    enum:
> > > > > +      - sysclkout
> > > > > +      - fck
> > > > > +
> > > >
> > > > If we are making this optional for ti,am62-eqep, why add a new name?
> > > >
> > > > Also, we could change the description to say that sysclockout is not a
> > > > great name but is required for backwards compatibility.
> > > >
> > > > > +  power-domains:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +allOf:
> > > > > +  - if:
> > > > > +      properties:
> > > > > +        compatible:
> > > > > +          contains:
> > > > > +            enum:
> > > > > +              - ti,am3352-eqep
> > > > > +    then:
> > > > > +      required:
> > > > > +        - clock-names
> > >
> > > I just looked at the Linux driver for this and the clock name is
> > > not used in the driver. So we could probably just deprecate the
> > > clock-names property here and not make it required for
> > > ti,am3352-eqep (and not allowed for any new compatibles as
> > > suggested below).
> >
> > We could do this, although I was under the impression that we should
> > not drop DT properties just because the linux driver isn't using it,
> > that is why I went with keeping clock-names around for am335x compatible
> > and making it optional for am62x compatible.
> >
> > But if it is all the same, we could drop the the DT property.
> >
> > ~ Judith
>
> I wasn't suggesting to remove clock-names from the bindings, just
> deprecate that property in this binding and not use it with any
> new compatibles.
>
> In the AM62x technical reference manual, it looks like it calls
> the functional and interface clock FICLK rather than FCK. So
> I'm just suggesting maybe it just easier to not give it a name
> rather than try to get the right name? No name will work with
> any future SoCs as well. :-)

Understood, so I will make clock-names optional for ti,am3352-eqep
compatible and not allowed for ti,am62-eqep compatible.

Thanks for your feedback (:

~ Judith
>