Re: [PATCH v13 01/10] dt-bindings: mediatek,dp: Add Display Port binding

[Rex-BC Chen <rex-bc.chen@mediatek.com>]

On Fri, 2022-07-01 at 14:29 -0600, Rob Herring wrote:
> On Fri, Jul 01, 2022 at 02:27:59PM +0800, Bo-Chen Chen wrote:
> > From: Markus Schneider-Pargmann <msp@baylibre.com>
> > 
> > This controller is present on several mediatek hardware. Currently
> > mt8195 and mt8395 have this controller without a functional
> > difference,
> > so only one compatible field is added.
> > 
> > The controller can have two forms, as a normal display port and as
> > an
> > embedded display port.
> 
> I'm sure you answered this before, but I'll keep asking until the 
> information is contained within this patch. Otherwise, I won't
> remember. 
> Is there a h/w difference in the 2 blocks? Different registers? Why 
> can't you just look at what the output is connected to?
> 

Hello Rob,

Thanks for your review.
Yes, it's two different hw for edp and dp and they have different
registers base address.
I will add this information in next version.

> > 
> > Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
> > Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> > Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
> > ---
> >  .../display/mediatek/mediatek,dp.yaml         | 108
> > ++++++++++++++++++
> >  1 file changed, 108 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/display/mediatek/mediatek,dp.yaml
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/display/mediatek/mediatek,dp.ya
> > ml
> > b/Documentation/devicetree/bindings/display/mediatek/mediatek,dp.ya
> > ml
> > new file mode 100644
> > index 000000000000..26047fc65e7d
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/display/mediatek/mediatek,dp.ya
> > ml
> > @@ -0,0 +1,108 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: 
> > https://urldefense.com/v3/__http://devicetree.org/schemas/display/mediatek/mediatek,dp.yaml*__;Iw!!CTRNKA9wMg0ARbw!0rhwy9BSTdon0PvJuF9KabbkL9STTTnUEnTBbW_pQD_ZJP7Ziu6lhepb8fUWCnoLWHAXfmmVC6-qsI6YUpPv_qzirg$
> >  
> > +$schema: 
> > https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!0rhwy9BSTdon0PvJuF9KabbkL9STTTnUEnTBbW_pQD_ZJP7Ziu6lhepb8fUWCnoLWHAXfmmVC6-qsI6YUpOIsTMz8Q$
> >  
> > +
> > +title: MediaTek Display Port Controller
> > +
> > +maintainers:
> > +  - Chun-Kuang Hu <chunkuang.hu@kernel.org>
> > +  - Jitao shi <jitao.shi@mediatek.com>
> > +
> > +description: |
> > +  Device tree bindings for the MediaTek display port and
> > +  embedded display port controller present on some MediaTek SoCs.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - mediatek,mt8195-dp-tx
> > +      - mediatek,mt8195-edp-tx
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  nvmem-cells:
> > +    maxItems: 1
> > +    description: efuse data for display port calibration
> > +
> > +  nvmem-cell-names:
> > +    const: dp_calibration_data
> > +
> > +  power-domains:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  ports:
> > +    $ref: /schemas/graph.yaml#/properties/ports
> > +    properties:
> > +      port@0:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Input endpoint of the controller, usually
> > dp_intf
> > +
> > +      port@1:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Output endpoint of the controller
> > +
> > +    required:
> > +      - port@0
> > +      - port@1
> > +
> > +  data-lanes:
> 
> This is not where data-lanes belongs. It goes in port@1 endpoint.
> Look 
> at other users.
> 

Do you mean I need to put "data-lanes" inside port?

BRs,
Bo-Chen
> > +    $ref: /schemas/media/video-interfaces.yaml#/properties/data-
> > lanes
> 
> Generally, not how references look in DT bindings.
> 
> > +    description: |
> > +      number of lanes supported by the hardware.
> > +      The possible values:
> > +      0       - For 1 lane enabled in IP.
> > +      0 1     - For 2 lanes enabled in IP.
> > +      0 1 2 3 - For 4 lanes enabled in IP.
> > +    minItems: 1
> > +    maxItems: 4
> > +
> > +  max-linkrate-mhz:
> > +    enum: [ 1620, 2700, 5400, 8100 ]
> > +    description: maximum link rate supported by the hardware.
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - ports
> > +  - data-lanes
> > +  - max-linkrate-mhz
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/power/mt8195-power.h>
> > +    dp_tx@1c600000 {
> > +        compatible = "mediatek,mt8195-dp-tx";
> > +        reg = <0x1c600000 0x8000>;
> > +        power-domains = <&spm MT8195_POWER_DOMAIN_DP_TX>;
> > +        interrupts = <GIC_SPI 458 IRQ_TYPE_LEVEL_HIGH 0>;
> > +        data-lanes = <0 1 2 3>;
> > +        max-linkrate-mhz = <8100>;
> > +
> > +        ports {
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +
> > +            port@0 {
> > +                reg = <0>;
> > +                edp_in: endpoint {
> > +                    remote-endpoint = <&dp_intf0_out>;
> > +                };
> > +            };
> > +            port@1 {
> > +                reg = <1>;
> > +                edp_out: endpoint {
> > +                    remote-endpoint = <&panel_in>;
> > +                };
> > +            };
> > +        };
> > +    };
> > -- 
> > 2.18.0
> > 
> >