Re: [PATCH v5 1/2] dt-bindings: memory: mediatek: Add SMI reset and clamp for MT8188

[AngeloGioacchino Del Regno]

Il 11/03/25 13:23, Friday Yang ha scritto:
> From: "Friday Yang" <friday.yang@xxxxxxxxxxxx>
>
> On the MediaTek platform, some SMI LARBs are directly connected to
> the SMI Common, while others are connected to the SMI Sub-Common,
> which in turn is connected to the SMI Common. The hardware block
> diagram can be described as follows.
>
>               SMI-Common(Smart Multimedia Interface Common)
>                   |
>           +----------------+------------------+
>           |                |                  |
>           |                |                  |
>           |                |                  |
>           |                |                  |
>           |                |                  |
>         larb0       SMI-Sub-Common0     SMI-Sub-Common1
>                     |      |     |      |             |
>                    larb1  larb2 larb3  larb7       larb9
>
> For previous discussion on the direction of the code modifications,
> please refer to:
> https://lore.kernel.org/all/CAFGrd9qZhObQXvm2_abqaX83xMLqxjQETB2=wXpobDWU1CnvkA@xxxxxxxxxxxxxx/
> https://lore.kernel.org/all/CAPDyKFpokXV2gJDgowbixTvOH_5VL3B5H8eyhP+KJ5Fasm2rFg@xxxxxxxxxxxxxx/
>
> On the MediaTek MT8188 SoC platform, we encountered power-off failures
> and SMI bus hang issues during camera stress tests. The issue arises
> because bus glitches are sometimes produced when MTCMOS powers on or
> off. While this is fairly normal, the software must handle these
> glitches to avoid mistaking them for transaction signals. What's
> more, this issue emerged only after the initial upstreaming of this
> binding. Without these patches, the SMI becomes unstable during camera
> stress tests.
>
> The software solutions can be summarized as follows:
>
> 1. Use CLAMP to disable the SMI sub-common port after turning off the
>     LARB CG and before turning off the LARB MTCMOS.
> 2. Use CLAMP to disable/enable the SMI sub-common port.
> 3. Implement an AXI reset for SMI LARBs.
>
> This patch primarily add two changes:
> 1. Add compatible for SMI sub-common on MT8188 SoC.
> 2. Add 'resets' and 'reset-names' properties for SMI LARBs to
>     support SMI reset operations.
>
> Signed-off-by: Friday Yang <friday.yang@xxxxxxxxxxxx>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>