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Message-ID: <6796f082-dfbe-45dc-bd01-3c9b4ac73865@collabora.com>
Date: Mon, 13 May 2024 15:44:00 +0200
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Subject: Re: [PATCH v2 2/3] dt-bindings: arm: mediatek: mmsys: Add OF graph
 support for board path
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References: <20240409120211.321153-1-angelogioacchino.delregno@collabora.com>
 <20240409120211.321153-3-angelogioacchino.delregno@collabora.com>
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 <46347f5d-e09b-4e83-a5a2-e12407f442a4@collabora.com>
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 <34caf545-1fc9-4905-a82f-2596f053b3ff@collabora.com>
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From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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Il 13/05/24 08:15, CK Hu (胡俊光) ha scritto:
> On Fri, 2024-05-10 at 12:14 +0200, AngeloGioacchino Del Regno wrote:
>> Il 10/05/24 11:34, CK Hu (胡俊光) ha scritto:
>>> On Thu, 2024-05-09 at 11:27 +0200, AngeloGioacchino Del Regno
>>> wrote:
>>>> Il 09/05/24 07:42, CK Hu (胡俊光) ha scritto:
>>>>> On Wed, 2024-05-08 at 15:03 +0200, AngeloGioacchino Del Regno
>>>>> wrote:
>>>>>> Il 08/05/24 09:19, CK Hu (胡俊光) ha scritto:
>>>>>>> On Tue, 2024-05-07 at 16:07 +0200, AngeloGioacchino Del
>>>>>>> Regno
>>>>>>> wrote:
>>>>>>>> Il 07/05/24 08:59, CK Hu (胡俊光) ha scritto:
>>>>>>>>> On Thu, 2024-05-02 at 10:50 +0200, AngeloGioacchino Del
>>>>>>>>> Regno
>>>>>>>>> wrote:
>>>>>>>>>> Il 25/04/24 04:23, CK Hu (胡俊光) ha scritto:
>>>>>>>>>>> Hi, Angelo:
>>>>>>>>>>>
>>>>>>>>>>> On Tue, 2024-04-09 at 14:02 +0200, AngeloGioacchino
>>>>>>>>>>> Del
>>>>>>>>>>> Regno
>>>>>>>>>>> wrote:
>>>>>>>>>>>> Document OF graph on MMSYS/VDOSYS: this supports
>>>>>>>>>>>> up
>>>>>>>>>>>> to
>>>>>>>>>>>> three
>>>>>>>>>>>> DDP
>>>>>>>>>>>> paths
>>>>>>>>>>>> per HW instance (so potentially up to six
>>>>>>>>>>>> displays
>>>>>>>>>>>> for
>>>>>>>>>>>> multi-
>>>>>>>>>>>> vdo
>>>>>>>>>>>> SoCs).
>>>>>>>>>>>>
>>>>>>>>>>>> The MMSYS or VDOSYS is always the first component
>>>>>>>>>>>> in
>>>>>>>>>>>> the
>>>>>>>>>>>> DDP
>>>>>>>>>>>> pipeline,
>>>>>>>>>>>> so it only supports an output port with multiple
>>>>>>>>>>>> endpoints -
>>>>>>>>>>>> where
>>>>>>>>>>>> each
>>>>>>>>>>>> endpoint defines the starting point for one of
>>>>>>>>>>>> the
>>>>>>>>>>>> (currently
>>>>>>>>>>>> three)
>>>>>>>>>>>> possible hardware paths.
>>>>>>>>>>>>
>>>>>>>>>>>> Signed-off-by: AngeloGioacchino Del Regno <
>>>>>>>>>>>> angelogioacchino.delregno@collabora.com>
>>>>>>>>>>>> ---
>>>>>>>>>>>>        .../bindings/arm/mediatek/mediatek,mmsys.ya
>>>>>>>>>>>> ml |
>>>>>>>>>>>> 23
>>>>>>>>>>>> +++++++++++++++++++
>>>>>>>>>>>>        1 file changed, 23 insertions(+)
>>>>>>>>>>>>
>>>>>>>>>>>> diff --git
>>>>>>>>>>>> a/Documentation/devicetree/bindings/arm/mediatek/
>>>>>>>>>>>> medi
>>>>>>>>>>>> atek
>>>>>>>>>>>> ,mms
>>>>>>>>>>>> ys.y
>>>>>>>>>>>> aml
>>>>>>>>>>>> b/Documentation/devicetree/bindings/arm/mediatek/
>>>>>>>>>>>> medi
>>>>>>>>>>>> atek
>>>>>>>>>>>> ,mms
>>>>>>>>>>>> ys.y
>>>>>>>>>>>> aml
>>>>>>>>>>>> index b3c6888c1457..4e9acd966aa5 100644
>>>>>>>>>>>> ---
>>>>>>>>>>>> a/Documentation/devicetree/bindings/arm/mediatek/
>>>>>>>>>>>> medi
>>>>>>>>>>>> atek
>>>>>>>>>>>> ,mms
>>>>>>>>>>>> ys.y
>>>>>>>>>>>> aml
>>>>>>>>>>>> +++
>>>>>>>>>>>> b/Documentation/devicetree/bindings/arm/mediatek/
>>>>>>>>>>>> medi
>>>>>>>>>>>> atek
>>>>>>>>>>>> ,mms
>>>>>>>>>>>> ys.y
>>>>>>>>>>>> aml
>>>>>>>>>>>> @@ -93,6 +93,29 @@ properties:
>>>>>>>>>>>>          '#reset-cells':
>>>>>>>>>>>>            const: 1
>>>>>>>>>>>>        
>>>>>>>>>>>> +  port:
>>>>>>>>>>>> +    $ref: /schemas/graph.yaml#/properties/port
>>>>>>>>>>>> +    description:
>>>>>>>>>>>> +      Output port node. This port connects the
>>>>>>>>>>>> MMSYS/VDOSYS
>>>>>>>>>>>> output
>>>>>>>>>>>> to
>>>>>>>>>>>> +      the first component of one display
>>>>>>>>>>>> pipeline,
>>>>>>>>>>>> for
>>>>>>>>>>>> example
>>>>>>>>>>>> one
>>>>>>>>>>>> of
>>>>>>>>>>>> +      the available OVL or RDMA blocks.
>>>>>>>>>>>> +      Some MediaTek SoCs support up to three
>>>>>>>>>>>> display
>>>>>>>>>>>> outputs
>>>>>>>>>>>> per
>>>>>>>>>>>> MMSYS.
>>>>>>>>>>>> +    properties:
>>>>>>>>>>>> +      endpoint@0:
>>>>>>>>>>>> +        $ref:
>>>>>>>>>>>> /schemas/graph.yaml#/properties/endpoint
>>>>>>>>>>>> +        description: Output to the primary
>>>>>>>>>>>> display
>>>>>>>>>>>> pipeline
>>>>>>>>>>>> +
>>>>>>>>>>>> +      endpoint@1:
>>>>>>>>>>>> +        $ref:
>>>>>>>>>>>> /schemas/graph.yaml#/properties/endpoint
>>>>>>>>>>>> +        description: Output to the secondary
>>>>>>>>>>>> display
>>>>>>>>>>>> pipeline
>>>>>>>>>>>> +
>>>>>>>>>>>> +      endpoint@2:
>>>>>>>>>>>> +        $ref:
>>>>>>>>>>>> /schemas/graph.yaml#/properties/endpoint
>>>>>>>>>>>> +        description: Output to the tertiary
>>>>>>>>>>>> display
>>>>>>>>>>>> pipeline
>>>>>>>>>>>> +
>>>>>>>>>>>> +    required:
>>>>>>>>>>>> +      - endpoint@0
>>>>>>>>>>>> +
>>>>>>>>>>>
>>>>>>>>>>> mmsys/vdosys does not output data to the first
>>>>>>>>>>> component of
>>>>>>>>>>> display
>>>>>>>>>>> pipeline, so this connection looks 'virtual'. Shall
>>>>>>>>>>> we
>>>>>>>>>>> add
>>>>>>>>>>> something
>>>>>>>>>>> virtual in device tree? You add this in order to
>>>>>>>>>>> decide
>>>>>>>>>>> which
>>>>>>>>>>> pipeline
>>>>>>>>>>> is 1st, 2nd, 3rd, but for device it don't care
>>>>>>>>>>> which
>>>>>>>>>>> one is
>>>>>>>>>>> first.
>>>>>>>>>>> In
>>>>>>>>>>> computer, software could change which display is
>>>>>>>>>>> the
>>>>>>>>>>> primary
>>>>>>>>>>> display.
>>>>>>>>>>> I'm not sure it's good to decide display order in
>>>>>>>>>>> device
>>>>>>>>>>> tree?
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Devicetree describes hardware, so nothing virtual can
>>>>>>>>>> be
>>>>>>>>>> present
>>>>>>>>>> -
>>>>>>>>>> and in any case,
>>>>>>>>>> the primary/secondary/tertiary pipeline is in
>>>>>>>>>> relation to
>>>>>>>>>> MM/VDO
>>>>>>>>>> SYS,
>>>>>>>>>> not referred
>>>>>>>>>> to software.
>>>>>>>>>>
>>>>>>>>>> Better explaining, the primary pipeline is not
>>>>>>>>>> necessarily
>>>>>>>>>> the
>>>>>>>>>> primary display in
>>>>>>>>>> DRM terms: that's a concept that is completely
>>>>>>>>>> detached
>>>>>>>>>> from
>>>>>>>>>> the
>>>>>>>>>> scope of this
>>>>>>>>>> series and this graph - and it's something that shall
>>>>>>>>>> be
>>>>>>>>>> managed
>>>>>>>>>> solely by the
>>>>>>>>>> driver (mediatek-drm in this case).
>>>>>>>>>>
>>>>>>>>>> Coming back to the connection looking, but *not*
>>>>>>>>>> being
>>>>>>>>>> virtual:
>>>>>>>>>> the
>>>>>>>>>> sense here is
>>>>>>>>>> that the MM/VDOSYS blocks are used in the display
>>>>>>>>>> pipeline to
>>>>>>>>>> "stitch" together
>>>>>>>>>> the various display pipeline hardware blocks, or,
>>>>>>>>>> said
>>>>>>>>>> differently,
>>>>>>>>>> setting up the
>>>>>>>>>> routing between all of those (P.S.:
>>>>>>>>>> mmsys_mtxxxx_routing_table!)
>>>>>>>>>> through the VDO
>>>>>>>>>> Input Selection (VDOx_SEL_IN) or Output Selection
>>>>>>>>>> (VDOx_SEL_OUT)
>>>>>>>>>> and
>>>>>>>>>> with the
>>>>>>>>>> assistance of the VDO Multiple Output Mask
>>>>>>>>>> (VDOx_MOUT)
>>>>>>>>>> for
>>>>>>>>>> the
>>>>>>>>>> multiple outputs
>>>>>>>>>> usecase, both of which, are described by this graph.
>>>>>>>>>
>>>>>>>>> I agree this part, but this is related to display
>>>>>>>>> device OF
>>>>>>>>> graph.
>>>>>>>>> These display device would output video data from one
>>>>>>>>> device
>>>>>>>>> and
>>>>>>>>> input
>>>>>>>>> to another video device. These video device would not
>>>>>>>>> input
>>>>>>>>> or
>>>>>>>>> output
>>>>>>>>> video data to mmsys/vdosys.
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> This means that the VDOSYS is really the "master" of
>>>>>>>>>> the
>>>>>>>>>> display
>>>>>>>>>> pipeline since
>>>>>>>>>> everything gets enabled, mixed and matched from there
>>>>>>>>>> -
>>>>>>>>>> and
>>>>>>>>>> that's in
>>>>>>>>>> the sense
>>>>>>>>>> of hardware operation, so we are *really* (and not
>>>>>>>>>> virtually!)
>>>>>>>>>> flipping switches.
>>>>>>>>>
>>>>>>>>> I agree mmsys/vdosys is master of video pipeline, so
>>>>>>>>> let's
>>>>>>>>> define
>>>>>>>>> what
>>>>>>>>> the port in mmsys/vdosys is. If the port means the
>>>>>>>>> master
>>>>>>>>> relationship,
>>>>>>>>> mmsys/vdosys should output port to every display
>>>>>>>>> device. Or
>>>>>>>>> use
>>>>>>>>> a
>>>>>>>>> simply way to show the master relation ship
>>>>>>>>>
>>>>>>>>> mmsys-subdev = <&ovl0, &rdma0, &color0, ...>, <&ovl1,
>>>>>>>>> &rdma1,
>>>>>>>>> &color1,
>>>>>>>>> ...>;
>>>>>>>>>
>>>>>>>>
>>>>>>>> There's no need to list all of the VDO0/VDO1/mmsys
>>>>>>>> devices in
>>>>>>>> one
>>>>>>>> big
>>>>>>>> array
>>>>>>>> property, because the actual possible devices can be
>>>>>>>> defined:
>>>>>>>>        1. In the bindings; and
>>>>>>>>        2. In the actual OF graph that we write for each
>>>>>>>> SoC+board
>>>>>>>> combination.
>>>>>>>>
>>>>>>>> A graph cannot contain a connection to a device that
>>>>>>>> cannot
>>>>>>>> be
>>>>>>>> connected to
>>>>>>>> the previous, so, your "mmsys-subdev" list can be
>>>>>>>> retrieved
>>>>>>>> by
>>>>>>>> looking at the
>>>>>>>> graph:
>>>>>>>>       - Start from VDO0/1 or MMSYS
>>>>>>>>       - Walk through (visually, even) OUTPUT ports
>>>>>>>>         - VDO0 (read output ep) -> ovl0 (read output ep)
>>>>>>>> ->
>>>>>>>> rdma0
>>>>>>>> (read
>>>>>>>> output ep) ->
>>>>>>>>           color0 (...) -> etc
>>>>>>>>       - Nothing more - it's all defined there.
>>>>>>>>
>>>>>>>>>
>>>>>>>>> Another problem is how to group display device? If two
>>>>>>>>> pipeline
>>>>>>>>> could
>>>>>>>>> be route to the same display interface, such as
>>>>>>>>>
>>>>>>>>> rdma0 -> dsi
>>>>>>>>> rdma1 -> dsi
>>>>>>>>>
>>>>>>>>> Would this be single group?
>>>>>>>>
>>>>>>>> There are multiple ways of doing this, but one that comes
>>>>>>>> to
>>>>>>>> my
>>>>>>>> mind
>>>>>>>> right now and
>>>>>>>> that looks clean as well is the following:
>>>>>>>>
>>>>>>>> ovl0@ef01 {
>>>>>>>>         .....
>>>>>>>>        ports {
>>>>>>>>          port@0 {
>>>>>>>>            reg = <0>;
>>>>>>>>            ovl0_in: endpoint {
>>>>>>>>              remote-endpoint = <&vdosys0_out>;
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>
>>>>>>> I'm not sure how do you define this port from OVL to
>>>>>>> vdosys. If
>>>>>>> this
>>>>>>> port means 'master relationship', others could add port in
>>>>>>> COLOR to
>>>>>>> point to vdosys because COLOR and vdosys has the 'master
>>>>>>> relationship'
>>>>>>> and I could not reject this. So we need more specific
>>>>>>> definition of
>>>>>>> this port.
>>>>>>
>>>>>>
>>>>>>> Only the 'first' device in pipeline could have this port?
>>>>>>
>>>>>> Correct. Only the first device in a pipeline - and this is
>>>>>> actually a
>>>>>> restriction
>>>>>> that the generic binding definition of port already gives, in
>>>>>> a
>>>>>> way.
>>>>>>
>>>>>>
>>>>>>> In mt8173, one pipeline is
>>>>>>>
>>>>>>> ovl -> color -> aal -> od -> rdma -> ufo -> dsi
>>>>>>>
>>>>>>> But rdma has an option to read data from od or directly
>>>>>>> from
>>>>>>> DRAM.
>>>>>>> If
>>>>>>> from DRAM, the pipeline would be changed to
>>>>>>>
>>>>>>> rdma -> ufo -> dsi
>>>>>>>
>>>>>>>
>>>>>>> So it's confused which one is 'first'.
>>>>>>
>>>>>> That's why the pipeline is *board-specific* and not soc-
>>>>>> generic!
>>>>>>
>>>>>> And what you described is *exactly* the reason why I'm adding
>>>>>> support
>>>>>> for the
>>>>>> OF graphs in mediatek-drm: specifying the correct pipeline
>>>>>> for
>>>>>> each
>>>>>> board as per
>>>>>> what each board wants to use (said differently: for each
>>>>>> board's
>>>>>> *capabilities*).
>>>>>>
>>>>>> So, if on a certain board you want to skip OD, you can hook
>>>>>> RDMA
>>>>>> up
>>>>>> directly to
>>>>>> MMSYS/VDOSYS.
>>>>>>
>>>>>> In MT8173, one pipeline for one board uses endpoints IN/OUT
>>>>>> like
>>>>>> this:
>>>>>>
>>>>>> MMSYS -> OVL -> COLOR -> AAL -> OD -> RDMA -> UFO -> DSI
>>>>>>
>>>>>> and for another board, endpoints will be like
>>>>>>
>>>>>> MMSYS -> RDMA -> UFO -> DSI
>>>>>>
>>>>>> ...which is the exact same as you described, and I think that
>>>>>> your
>>>>>> confusion comes
>>>>>> from the fact that you didn't put MMSYS at the beginning of
>>>>>> the
>>>>>> pipeline :-)
>>>>>
>>>>> In one board, both OVL and RDMA could switch dynamically.
>>>>> Because
>>>>> each
>>>>> one could be the first in one board, mmsys point to both ovl
>>>>> and
>>>>> rdma?
>>>>>
>>>>
>>>> No.
>>>>
>>>> MMSYS would still point ONLY to OVL, because OVL is the "earliest
>>>> point"
>>>> of the pipeline that this one board does support.
>>>>
>>>> In that case, RDMA being present at a later point in the pipeline
>>>> does not
>>>> matter and does not prevent us from *temporarily* skipping OVL-
>>>> COLOR-
>>>> AAL-OD
>>>> and going MMSYS->RDMA *directly*.
>>>>
>>>> Switching dynamically is a driver duty and will be 100% possible
>>>> (as
>>>> much
>>>> as it is right now) to dynamically switch OVL and RDMA as long as
>>>> both are
>>>> present in the pipeline.
>>>>
>>>> With this exact pipeline:
>>>>
>>>> MMSYS -> OVL -> COLOR -> AAL -> OD -> RDMA -> UFO -> DSI
>>>>
>>>> the driver _can switch dynamically_ between MMSYS->OVL->...->RDMA
>>>> and
>>>> MMSYS->RDMA as the driver itself *is allowed to* temporarily
>>>> ignore
>>>> part
>>>> of the pipeline.
>>>>
>>>> Please note that, in case it is needed (trust me on this: it's
>>>> not
>>>> needed)
>>>> a custom property in the endpoint node can always be introduced
>>>> later, so
>>>> that you can declare a node like
>>>>
>>>>             endpoint@0 {
>>>>               remote-endpoint = <&ovl0_in>;
>>>>               mediatek,short-path = <&rdma0_in>;
>>>>             };
>>>>
>>>> ...but again, that's never going to be needed, as the driver
>>>> already
>>>> does
>>>> have knowledge of the fact that RDMA is in the pipeline, so it is
>>>> possible
>>>> to simply do a temporary override in the driver.
>>>>
>>>> What the OF Graph support does is to build the same arrays, that
>>>> we
>>>> currently
>>>> have hardcoded in mediatek-drm, by reading from device tree.
>>>>
>>>> Nothing else and nothing more - for now.
>>>>
>>>> Having the OF Graph support makes us able to also add new dual-
>>>> path
>>>> support
>>>> with more complicated connections than the current ones, without
>>>> any
>>>> problem
>>>> and, in many cases, without even modifying the bindings from what
>>>> I
>>>> provided
>>>> in this series.
>>>
>>> OK, please add the information we discussed into binding document
>>> to
>>> prevent anyone misusing this binding.
>>>
>>
>> Sorry CK, but the binding *does* already have this information inside
>> - not
>> in terms of "phrases", but in terms of restrictions of the binding...
>>
>> If you want, though, I can add this information in the description of
>> the
>> commit that is adding this binding, is that okay for you?
> 
> I think what we discuss could be translated to restrictions. This is a
> restriction description:
> 
> If one component has option to be first component or middle component
> of one pipeline, it's treated as middle component not first component.
> 
> In mt8195, there are 8 vdo1_rdma. So each one is the first component of
> display pipeline. So the maximum display pipe number is not 3, maybe 8
> or more.
> 

I will add the information in the commit description for the next version
of this series.

Thanks,
Angelo

> Regards,
> CK
> 
> 
>>
>> Thanks,
>> Angelo
>>
>>> Regards,
>>> CK
>>>
>>>>
>>>> Cheers,
>>>> Angelo
>>>>
>>>>> Regards,
>>>>> CK
>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> In case you need any *temporary override* on any board that
>>>>>> defines a
>>>>>> pipeline like
>>>>>>
>>>>>> MMSYS -> OVL -> COLOR -> AAL -> OD -> RDMA -> UFO -> DSI
>>>>>>
>>>>>> so that the pipeline *temporarily* becomes (for power
>>>>>> management,
>>>>>> or
>>>>>> for any other
>>>>>> reason) RDMA -> UFO -> DSI .... that's not a concern: the
>>>>>> graph
>>>>>> is
>>>>>> present, and it
>>>>>> is used to tell to the driver what is the regular pipeline to
>>>>>> use.
>>>>>> Eventual temporary overrides can be managed transparently
>>>>>> inside
>>>>>> of
>>>>>> the driver with
>>>>>> C code and no changes to the devicetree are required.
>>>>>>
>>>>>>
>>>>>>> I don't know how to decide which device could point to
>>>>>>> mmsys/vdosys. So
>>>>>>> please give a specific definition.
>>>>>>>
>>>>>>
>>>>>> Nothing points TO mmsys/vdosys. It is mmsys/vdosys pointing
>>>>>> to a
>>>>>> device.
>>>>>>
>>>>>> So, mmsys/vdosys must point to the *first device in the
>>>>>> pipeline*.
>>>>>>
>>>>>> Any other doubt?
>>>>>>
>>>>>> Cheers,
>>>>>> Angelo
>>>>>>
>>>>>>> Regards,
>>>>>>> CK
>>>>>>>
>>>>>>>>
>>>>>>>>          port@1 {
>>>>>>>>            reg = <1>;
>>>>>>>>            ovl0_out0: endpoint@0 {
>>>>>>>>              remote-endpoint = <&rdma0_in>;
>>>>>>>>            };
>>>>>>>>            ovl0_out1: endpoint@1 {
>>>>>>>>              remote-endpoint = <&rdma1_in>;
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>>        };
>>>>>>>> };
>>>>>>>>
>>>>>>>> rdma0@1234 {
>>>>>>>>         .....
>>>>>>>>        ports {
>>>>>>>>          port@0 {
>>>>>>>>            reg = <0>;
>>>>>>>>            rdma0_in: endpoint {
>>>>>>>>              remote-endpoint = <&ovl0_out0>; /* assuming
>>>>>>>> ovl0
>>>>>>>> outputs to
>>>>>>>> rdma0...*/
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>>          port@1 {
>>>>>>>>            reg = <1>;
>>>>>>>>            rdma0_out: endpoint@1 {
>>>>>>>>              remote-endpoint = <&dsi_dual_intf0_in>;
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>>        };
>>>>>>>> };
>>>>>>>>
>>>>>>>>
>>>>>>>> rdma1@5678 {
>>>>>>>>         .....
>>>>>>>>        ports {
>>>>>>>>          port@0 {
>>>>>>>>            reg = <0>;
>>>>>>>>            rdma1_in: endpoint {
>>>>>>>>              /* assuming ovl0 outputs to rdma1 as well...
>>>>>>>> can
>>>>>>>> be
>>>>>>>> something else. */
>>>>>>>>              remote-endpoint = <&ovl0_out1>;
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>>          port@1 {
>>>>>>>>            reg = <1>;
>>>>>>>>            rdma1_out: endpoint {
>>>>>>>>              remote-endpoint = <&dsi_dual_intf1_in>;
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>>        };
>>>>>>>> };
>>>>>>>>
>>>>>>>>
>>>>>>>> dsi@9abcd {
>>>>>>>>         .....
>>>>>>>>        ports {
>>>>>>>>          port@0 {
>>>>>>>>            reg = <0>;
>>>>>>>>            /* Where endpoint@0 could be always DSI LEFT
>>>>>>>> CTRL */
>>>>>>>>            dsi_dual_intf0_in: endpoint@0 {
>>>>>>>>              remote-endpoint = <&rdma0_out>;
>>>>>>>>            };
>>>>>>>>            /* ...and @1 could be always DSI RIGHT CTRL */
>>>>>>>>            dsi_dual_intf1_in: endpoint@1 {
>>>>>>>>              remote-endpoint = <&rdma1_out>;
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>>
>>>>>>>>          port@1 {
>>>>>>>>            reg = <1>;
>>>>>>>>            dsi0_out: endpoint {
>>>>>>>>              remote-endpoint = <&dsi_panel_in>;
>>>>>>>>            };
>>>>>>>>          };
>>>>>>>>        };
>>>>>>>> };
>>>>>>>>
>>>>>>>> ...for a dual-dsi panel, it'd be a similar graph.
>>>>>>>>
>>>>>>>> Cheers,
>>>>>>>> Angelo
>>>>>>>>
>>>>>>>>>
>>>>>>>>> mmsys-subdev = <&rdma0, &rdma1, &dsi>;
>>>>>>>>>
>>>>>>>>> Or two group?
>>>>>>>>>
>>>>>>>>> mmsys-subdev = <&rdma0, &dsi>, <&rdma1, &dsi>;
>>>>>>>>>
>>>>>>>>> I think we should clearly define this.
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> CK
>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Cheers,
>>>>>>>>>> Angelo
>>>>>>>>>>
>>>>>>>>>>> Regards,
>>>>>>>>>>> CK
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>>        required:
>>>>>>>>>>>>          - compatible
>>>>>>>>>>>>          - reg
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>
>>>>>>
>>>>
>>>>
>>>>
>>