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

From: David Lechner
Date: Fri May 24 2024 - 16:58:25 EST


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).

>
> What if we just add
>
> else:
> clock-names: false
>
> since there is only one clock and not worry about the name?
>
>> + - if:
>> + properties:
>> + compatible:
>> + contains:
>> + enum:
>> + - ti,am62-eqep
>> + then:
>> + required:
>> + - power-domains
>>
>> required:
>> - compatible
>> - reg
>> - interrupts
>> - clocks
>> - - clock-names
>>