Re: [PATCH 1/2] dt-bindings: display: bridge: Add schema for Synopsys DW HDMI QP TX IP

[Cristian Ciocaltea <cristian.ciocaltea@collabora.com>]

On 8/1/24 11:38 AM, Krzysztof Kozlowski wrote:> On 01/08/2024 04:05, Cristian Ciocaltea wrote:
>> Add dt-binding schema containing the common properties for the Synopsys
>> DesignWare HDMI QP TX controller.
>>
>> Note this is not a full dt-binding specification, but is meant to be
>> referenced by platform-specific bindings for this IP core.
> 
> Please provide an user for this binding. Otherwise it is a no-op.

The first user of this is RK3588 HDMI TX Controller [1].

>>
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>> ---
>>  .../display/bridge/synopsys,dw-hdmi-qp.yaml        | 66 ++++++++++++++++++++++
>>  1 file changed, 66 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/bridge/synopsys,dw-hdmi-qp.yaml b/Documentation/devicetree/bindings/display/bridge/synopsys,dw-hdmi-qp.yaml
>> new file mode 100644
>> index 000000000000..d8aee12b121d
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/bridge/synopsys,dw-hdmi-qp.yaml
>> @@ -0,0 +1,66 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/display/bridge/synopsys,dw-hdmi-qp.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Common Properties for Synopsys DesignWare HDMI QP TX Controller IP
>> +
>> +maintainers:
>> +  - Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>> +
>> +description: |
>> +  This document defines device tree properties for the Synopsys DesignWare
>> +  HDMI 2.1 Quad-Pixel (QP) TX controller IP core.
>> +  It doesn't constitute a device tree binding specification by itself, but
>> +  is meant to be referenced by platform-specific device tree bindings.
>> +
>> +  When referenced from platform device tree bindings, the properties defined
>> +  in this document are defined as follows. The platform device tree bindings
>> +  are responsible for defining whether each property is required or optional.
> 
> Drop this all description and re-write it not to say what bindings are
> or are not. Describe the hardware.

I just tried to keep it similar with synopsys,dw-hdmi.yaml. 

> 
>> +
>> +properties:
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    minItems: 4
>> +    maxItems: 6
>> +    items:
>> +      - description: Peripheral/APB bus clock
>> +      - description: EARC RX biphase clock
>> +      - description: Reference clock
>> +      - description: Audio interface clock
>> +    additionalItems: true
> 
> ??? What's the point of such common schema if it is not common at all?

The schema is referenced by [1].
 
>> +
>> +  clock-names:
>> +    minItems: 4
>> +    maxItems: 6
>> +    items:
>> +      - const: pclk
>> +      - const: earc
>> +      - const: ref
>> +      - const: aud
>> +    additionalItems: true
>> +
>> +  interrupts:
>> +    minItems: 4
>> +    maxItems: 5
>> +    items:
>> +      - description: AVP Unit interrupt
>> +      - description: CEC interrupt
>> +      - description: eARC RX interrupt
>> +      - description: Main Unit interrupt
>> +    additionalItems: true
>> +
>> +  interrupt-names:
>> +    minItems: 4
>> +    maxItems: 5
>> +    items:
>> +      - const: avp
>> +      - const: cec
>> +      - const: earc
>> +      - const: main
>> +    additionalItems: true
> 
> Sorry, there is no user of this and nothing here is actually common
> except first entries in clocks and interrupts properties.
> 
> I don't see any benefit of this.

Sorry, I should have better indicated this is part of a larger changeset -
the cover mentions this is a reworked version of an initial (larger) series
and the split has been explicitly suggested during the review.

> Best regards,
> Krzysztof

Thanks for reviewing,
Cristian

[1]: https://lore.kernel.org/lkml/20240801-b4-rk3588-bridge-upstream-v2-1-9fa657a4e15b@collabora.com/