Re: [PATCH 01/24] dt-bindings: mediatek: mt8195: Add binding for MM IOMMU

From: Yong Wu
Date: Wed Jun 30 2021 - 03:31:23 EST


On Wed, 2021-06-30 at 08:26 +0200, Krzysztof Kozlowski wrote:
> On 30/06/2021 04:34, Yong Wu wrote:
> > This patch adds descriptions for mt8195 IOMMU which also use ARM
> > Short-Descriptor translation table format.
> >
> > In mt8195, there are two smi-common HW and IOMMU, one is for vdo(video
> > output), the other is for vpp(video processing pipe). They connects
> > with different smi-larbs, then some setting(larbid_remap) is different.
> > Differentiate them with the compatible string.
> >
> > Something like this:
> >
> > IOMMU(VDO) IOMMU(VPP)
> > | |
> > SMI_COMMON_VDO SMI_COMMON_VPP
> > --------------- ----------------
> > | | ... | | ...
> > larb0 larb2 ... larb1 larb3 ...
> >
> > Another change is that we have a new IOMMU that is for infra master like
> > PCIe and USB. The infra master don't have the larb and ports, thus we
> > rename the port header file to mt8195-memory-port.h rather than
> > mt8195-larb-port.h.
> >
> > Also, the IOMMU is not only for MM, thus, we don't call it "m4u" which
> > means "MultiMedia Memory Management UNIT". thus, use the "iommu" as the
> > compatiable string.
> >
> > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> > ---
> > .../bindings/iommu/mediatek,iommu.yaml | 7 +
> > .../dt-bindings/memory/mt8195-memory-port.h | 390 ++++++++++++++++++
> > 2 files changed, 397 insertions(+)
> > create mode 100644 include/dt-bindings/memory/mt8195-memory-port.h
> >
>
> I understand this will go through IOMMU tree. Do you know about any
> further patches for memory controllers which will need the header?

This header file will only be used in dtsi file. the iommu masters will
use these port definitions in the dtsi.

The SMI driver no need include this header file.

By the way, the mt8195 SMI patches is at:

https://lore.kernel.org/linux-mediatek/20210616114346.18812-1-yong.wu@xxxxxxxxxxxx/

>
> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>

Thanks very much for your quick review.

>
>
> Best regards,
> Krzysztof
>
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