Re: [PATCH v6 03/14] dt-bindings: display: bridge: Add i.MX8qm/qxp pixel combiner binding

[Liu Ying <victor.liu@nxp.com>]

Hi Marcel,

On Tue, 2021-03-23 at 00:34 +0000, Marcel Ziswiler wrote:
> On Wed, 2021-03-17 at 11:42 +0800, Liu Ying wrote:
> > This patch adds bindings for i.MX8qm/qxp pixel combiner.
> > 
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > Signed-off-by: Liu Ying <victor.liu@nxp.com>
> > ---
> > v5->v6:
> > * No change.
> > 
> > v4->v5:
> > * No change.
> > 
> > v3->v4:
> > * No change.
> > 
> > v2->v3:
> > * Add Rob's R-b tag.
> > 
> > v1->v2:
> > * Use graph schema. (Laurent)
> > * Use enum instead of oneOf + const for the reg property of pixel combiner
> >   channels. (Rob)
> > 
> >  .../display/bridge/fsl,imx8qxp-pixel-combiner.yaml | 144 +++++++++++++++++++++
> >  1 file changed, 144 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-combiner.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-combiner.yaml
> > b/Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-combiner.yaml
> > new file mode 100644
> > index 00000000..50bae21
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-combiner.yaml
> > @@ -0,0 +1,144 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetree.org%2Fschemas%2Fdisplay%2Fbridge%2Ffsl%2Cimx8qxp-pixel-combiner.yaml%23&amp;data=04%7C01%7Cvictor.liu%40nxp.com%7Cb83106f0261d4f715b4208d8ed936cb1%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637520564736692120%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=%2B4sZ3C9r3cewzQ01YHOvGk%2FCZaqQgg3ALftZ1dPLKIE%3D&amp;reserved=0
> > +$schema: https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevicetree.org%2Fmeta-schemas%2Fcore.yaml%23&amp;data=04%7C01%7Cvictor.liu%40nxp.com%7Cb83106f0261d4f715b4208d8ed936cb1%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637520564736692120%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=sP82pZYZXLKhzRRoYPR4C%2FFsDLUka1Fj0%2FA9InuWuvg%3D&amp;reserved=0
> > +
> > +title: Freescale i.MX8qm/qxp Pixel Combiner
> > +
> > +maintainers:
> > +  - Liu Ying <victor.liu@nxp.com>
> > +
> > +description: |
> > +  The Freescale i.MX8qm/qxp Pixel Combiner takes two output streams from a
> > +  single display controller and manipulates the two streams to support a number
> > +  of modes(bypass, pixel combine, YUV444 to YUV422, split_RGB) configured as
> > +  either one screen, two screens, or virtual screens.  The pixel combiner is
> > +  also responsible for generating some of the control signals for the pixel link
> > +  output channel.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - fsl,imx8qm-pixel-combiner
> > +      - fsl,imx8qxp-pixel-combiner
> > +
> > +  "#address-cells":
> > +    const: 1
> > +
> > +  "#size-cells":
> > +    const: 0
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  clock-names:
> > +    const: apb
> > +
> > +  power-domains:
> > +    maxItems: 1
> > +
> > +patternProperties:
> > +  "^channel@[0-1]$":
> > +    type: object
> > +    description: Represents a display stream of pixel combiner.
> > +
> > +    properties:
> > +      "#address-cells":
> > +        const: 1
> > +
> > +      "#size-cells":
> > +        const: 0
> > +
> > +      reg:
> > +        description: The display stream index.
> > +        enum: [ 0, 1 ]
> > +
> > +      port@0:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Input endpoint of the display stream.
> > +
> > +      port@1:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Output endpoint of the display stream.
> > +
> > +    required:
> > +      - "#address-cells"
> > +      - "#size-cells"
> > +      - reg
> > +      - port@0
> > +      - port@1
> > +
> > +    additionalProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - "#address-cells"
> > +  - "#size-cells"
> > +  - reg
> > +  - clocks
> > +  - clock-names
> > +  - power-domains
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/imx8-lpcg.h>
> > +    #include <dt-bindings/firmware/imx/rsrc.h>
> > +    pixel-combiner@56020000 {
> > +        compatible = "fsl,imx8qxp-pixel-combiner";
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +        reg = <0x56020000 0x10000>;
> > +        clocks = <&dc0_pixel_combiner_lpcg IMX_LPCG_CLK_4>;
> > +        clock-names = "apb";
> > +        power-domains = <&pd IMX_SC_R_DC_0>;
> > +
> > +        channel@0 {
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +            reg = <0>;
> > +
> > +            port@0 {
> > +                reg = <0>;
> > +
> > +                dc0_pixel_combiner_ch0_dc0_dpu_disp0: endpoint {
> > +                    remote-endpoint = <&dc0_dpu_disp0_dc0_pixel_combiner_ch0>;
> 
> While I acknowledge this just being an example you seem to call these as follows elsewhere:
> 
> Documentation/devicetree/bindings/display/bridge/fsl,imx8qxp-pixel-combiner.yaml
> 
> dc0_dpu_disp0_dc0_pixel_combiner_ch0
> pixel_combiner0_ch0_dpu0_disp0

Hmm, just like you said, this is just an example. And, it passes 'make
dt_binding_check'. Phandle 'pixel_combiner0_ch0_dpu0_disp0' is used in
the example of DPU[1]. It equals to phandle
'dc0_pixel_combiner_ch0_dc0_dpu_disp0' in this pixel combiner example. 

We'll eventually wire all those endpoints up to form display pipes in
real DT files with correct phandles. So, if no objections, I'll keep
those phandles as-is in the examples.

[1] https://www.spinics.net/lists/arm-kernel/msg878544.html

Regards,
Liu Ying

> 
> Or am I just missing something?
> 
> > +                };
> > +            };
> > +
> > +            port@1 {
> > +                reg = <1>;
> > +
> > +                dc0_pixel_combiner_ch0_dc0_pixel_link0: endpoint {
> > +                    remote-endpoint = <&dc0_pixel_link0_dc0_pixel_combiner_ch0>;
> > +                };
> > +            };
> > +        };
> > +
> > +        channel@1 {
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +            reg = <1>;
> > +
> > +            port@0 {
> > +                reg = <0>;
> > +
> > +                dc0_pixel_combiner_ch1_dc0_dpu_disp1: endpoint {
> > +                    remote-endpoint = <&dc0_dpu_disp1_dc0_pixel_combiner_ch1>;
> 
> ditto
> 
> > +                };
> > +            };
> > +
> > +            port@1 {
> > +                reg = <1>;
> > +
> > +                dc0_pixel_combiner_ch1_dc0_pixel_link1: endpoint {
> > +                    remote-endpoint = <&dc0_pixel_link1_dc0_pixel_combiner_ch1>;
> 
> do.
> 
> > +                };
> > +            };
> > +        };
> > +    };