Re: [PATCH v5, 13/15] dt-bindings: media: mtk-vcodec: Adds decoder dt-bindings for mt8192
From: yunfei.dong@xxxxxxxxxxxx
Date: Thu Sep 02 2021 - 02:09:10 EST
Hi Ezequiel,
Thanks for your suggestion.
On Wed, 2021-09-01 at 08:50 -0300, Ezequiel Garcia wrote:
> On Wed, 1 Sept 2021 at 00:49, yunfei.dong@xxxxxxxxxxxx
> <yunfei.dong@xxxxxxxxxxxx> wrote:
> >
> > Hi Ezequiel,
> >
> > Thanks for your feedback.
> > On Sun, 2021-08-29 at 17:54 -0300, Ezequiel Garcia wrote:
> > > On Tue, 17 Aug 2021 at 00:52, yunfei.dong@xxxxxxxxxxxx
> > > <yunfei.dong@xxxxxxxxxxxx> wrote:
> > > >
> > > > Hi Laurent,
> > > >
> > > > Thanks for your detail suggestion.
> > > >
> > > > On Wed, 2021-08-11 at 20:59 +0300, Laurent Pinchart wrote:
> > > > > Hi Yunfei,
> > > > >
> > > > > Thank you for the patch.
> > > > >
> > > > > On Wed, Aug 11, 2021 at 10:57:59AM +0800, Yunfei Dong wrote:
> > > > > > Adds decoder dt-bindings for mt8192.
> > > > > >
> > > > > > Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
> > > > > > ---
> > > > > > v5: no changes
> > > > > >
> > > > > > This patch depends on "Mediatek MT8192 clock support"[1].
> > > > > >
> > > > > > The definition of decoder clocks are in mt8192-clk.h, need
> > > > > > to
> > > > > > include them in case of build fail [1].
> > > > > >
> > > > > > [1]
> > > > > >
> >
> >
https://patchwork.kernel.org/project/linux-mediatek/list/?series=511175
> > > > > > ---
> > > > > > .../media/mediatek,vcodec-comp-decoder.yaml | 172
> > > > > > ++++++++++++++++++
> > > > > > 1 file changed, 172 insertions(+)
> > > > > > create mode 100644
> > > > > > Documentation/devicetree/bindings/media/mediatek,vcodec-
> > > > > > comp-
> > > > > > decoder.yaml
> > > > > >
> > > > > > diff --git
> > > > > > a/Documentation/devicetree/bindings/media/mediatek,vcodec-
> > > > > > comp-
> > > > > > decoder.yaml
> > > > > > b/Documentation/devicetree/bindings/media/mediatek,vcodec-
> > > > > > comp-
> > > > > > decoder.yaml
> > > > > > new file mode 100644
> > > > > > index 000000000000..083c89933917
> > > > > > --- /dev/null
> > > > > > +++
> > > > > > b/Documentation/devicetree/bindings/media/mediatek,vcodec-
> > > > > > comp-
> > > > > > decoder.yaml
> > > > > > @@ -0,0 +1,172 @@
> > > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > > > +%YAML 1.2
> > > > > > +---
> > > > > > +$id:
> > > > > >
> >
> >
http://devicetree.org/schemas/iommu/mediatek,vcodec-comp-decoder.yaml#
> > > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > > +
> > > > > > +title: Mediatek Video Decode Accelerator With Component
> > > > > > +
> > > > > > +maintainers:
> > > > > > + - Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
> > > > > > +
> > > > > > +description: |+
> > > > > > + Mediatek Video Decode is the video decode hardware
> > > > > > present
> > > > > > in
> > > > > > Mediatek
> > > > > > + SoCs which supports high resolution decoding
> > > > > > functionalities.
> > > > > > Required
> > > > > > + master and component node.
> > > > >
> > > > > This should explain how the three IP cores relate to each
> > > > > other.
> > > > >
> > > >
> > > > I will explain it in next patch.
> > > > > > +
> > > > > > +properties:
> > > > > > + compatible:
> > > > > > + oneOf:
> > > > > > + - enum:
> > > > > > + - mediatek,mt8192-vcodec-dec # for lat hardware
> > > > > > + - mediatek,mtk-vcodec-lat # for core
> > > > > > hardware
> > > > > > + - mediatek,mtk-vcodec-core
> > > > > > +
> > > > > > + reg:
> > > > > > + maxItems: 1
> > > > > > +
> > > > > > + interrupts:
> > > > > > + maxItems: 1
> > > > > > +
> > > > > > + clocks:
> > > > > > + maxItems: 5
> > > > > > +
> > > > > > + clock-names:
> > > > > > + items:
> > > > > > + - const: vdec-sel
> > > > > > + - const: vdec-soc-vdec
> > > > > > + - const: vdec-soc-lat
> > > > > > + - const: vdec-vdec
> > > > > > + - const: vdec-top
> > > > > > +
> > > > > > + assigned-clocks: true
> > > > > > +
> > > > > > + assigned-clock-parents: true
> > > > > > +
> > > > > > + power-domains:
> > > > > > + maxItems: 1
> > > > > > +
> > > > > > + iommus:
> > > > > > + minItems: 1
> > > > > > + maxItems: 32
> > > > > > + description: |
> > > > > > + List of the hardware port in respective IOMMU block
> > > > > > for
> > > > > > current Socs.
> > > > > > + Refer to bindings/iommu/mediatek,iommu.yaml.
> > > > > > +
> > > > > > + dma-ranges:
> > > > > > + maxItems: 1
> > > > > > + description: |
> > > > > > + Describes the physical address space of IOMMU maps
> > > > > > to
> > > > > > memory.
> > > > > > +
> > > > > > + mediatek,scp:
> > > > > > + $ref: /schemas/types.yaml#/definitions/phandle
> > > > > > + maxItems: 1
> > > > > > + description:
> > > > > > + Describes point to scp.
> > > > > > +
> > > > > > +required:
> > > > > > + - compatible
> > > > > > + - reg
> > > > > > + - iommus
> > > > > > + - dma-ranges
> > > > > > +
> > > > > > +allOf:
> > > > > > + - if: #master node
> > > > > > + properties:
> > > > > > + compatible:
> > > > > > + contains:
> > > > > > + enum:
> > > > > > + - mediatek,mt8192-vcodec-dec # for lat
> > > > > > hardware
> > > > > > +
> > > > > > + then:
> > > > > > + required:
> > > > > > + - mediatek,scp
> > > > > > +
> > > > > > + - if: #component node
> > > > > > + properties:
> > > > > > + compatible:
> > > > > > + contains:
> > > > > > + enum:
> > > > > > + - mediatek,mtk-vcodec-lat # for core
> > > > > > hardware
> > > > > > + - mediatek,mtk-vcodec-core
> > > > > > +
> > > > > > + then:
> > > > > > + required:
> > > > > > + - interrupts
> > > > > > + - clocks
> > > > > > + - clock-names
> > > > > > + - assigned-clocks
> > > > > > + - assigned-clock-parents
> > > > > > + - power-domains
> > > > > > +
> > > > > > +
> > > > > > +additionalProperties: false
> > > > > > +
> > > > > > +examples:
> > > > > > + - |
> > > > > > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > > > > + #include <dt-bindings/memory/mt8192-larb-port.h>
> > > > > > + #include <dt-bindings/interrupt-controller/irq.h>
> > > > > > + #include <dt-bindings/clock/mt8192-clk.h>
> > > > > > + #include <dt-bindings/power/mt8192-power.h>
> > > > > > +
> > > > > > + vcodec_dec: vcodec_dec@16000000 {
> > > > > > + compatible = "mediatek,mt8192-vcodec-dec";
> > > > > > + reg = <0 0x16000000 0 0x1000>; /*
> > > > > > VDEC_SYS
> > > > > > */
> > > > > > + mediatek,scp = <&scp>;
> > > > > > + iommus = <&iommu0 M4U_PORT_L4_VDEC_MC_EXT>;
> > > > > > + dma-ranges = <0x1 0x0 0x0 0x40000000 0x0
> > > > > > 0xfff00000>;
> > > > > > + };
> > > > > > +
> > > > > > + vcodec_lat: vcodec_lat@0x16010000 {
> > > > > > + compatible = "mediatek,mtk-vcodec-lat";
> > > > > > + reg = <0 0x16010000 0 0x800>; /*
> > > > > > VDEC_MISC */
> > > > > > + interrupts = <GIC_SPI 426 IRQ_TYPE_LEVEL_HIGH 0>;
> > > > > > + iommus = <&iommu0 M4U_PORT_L5_VDEC_LAT0_VLD_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L5_VDEC_LAT0_VLD2_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L5_VDEC_LAT0_AVC_MV_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L5_VDEC_LAT0_PRED_RD_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L5_VDEC_LAT0_TILE_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L5_VDEC_LAT0_WDMA_EXT>,
> > > > > > + <&iommu0
> > > > > > M4U_PORT_L5_VDEC_LAT0_RG_CTRL_DMA_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L5_VDEC_UFO_ENC_EXT>;
> > > > > > + dma-ranges = <0x1 0x0 0x0 0x40000000 0x0
> > > > > > 0xfff00000>;
> > > > > > + clocks = <&topckgen CLK_TOP_VDEC_SEL>,
> > > > > > + <&vdecsys_soc CLK_VDEC_SOC_VDEC>,
> > > > > > + <&vdecsys_soc CLK_VDEC_SOC_LAT>,
> > > > > > + <&vdecsys_soc CLK_VDEC_SOC_LARB1>,
> > > > > > + <&topckgen CLK_TOP_MAINPLL_D4>;
> > > > > > + clock-names = "vdec-sel", "vdec-soc-vdec", "vdec-
> > > > > > soc-
> > > > > > lat",
> > > > > > + "vdec-vdec", "vdec-top";
> > > > > > + assigned-clocks = <&topckgen CLK_TOP_VDEC_SEL>;
> > > > > > + assigned-clock-parents = <&topckgen
> > > > > > CLK_TOP_MAINPLL_D4>;
> > > > > > + power-domains = <&spm MT8192_POWER_DOMAIN_VDEC>;
> > > > > > + };
> > > > > > +
> > > > > > + vcodec_core: vcodec_core@0x16025000 {
> > > > > > + compatible = "mediatek,mtk-vcodec-core";
> > > > > > + reg = <0 0x16025000 0 0x1000>; /*
> > > > > > VDEC_CORE_MISC */
> > > > > > + interrupts = <GIC_SPI 425 IRQ_TYPE_LEVEL_HIGH 0>;
> > > > > > + iommus = <&iommu0 M4U_PORT_L4_VDEC_MC_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_UFO_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_PP_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_PRED_RD_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_PRED_WR_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_PPWRAP_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_TILE_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_VLD_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_VLD2_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_AVC_MV_EXT>,
> > > > > > + <&iommu0 M4U_PORT_L4_VDEC_RG_CTRL_DMA_EXT>;
> > > > > > + dma-ranges = <0x1 0x0 0x0 0x40000000 0x0
> > > > > > 0xfff00000>;
> > > > > > + clocks = <&topckgen CLK_TOP_VDEC_SEL>,
> > > > > > + <&vdecsys CLK_VDEC_VDEC>,
> > > > > > + <&vdecsys CLK_VDEC_LAT>,
> > > > > > + <&vdecsys CLK_VDEC_LARB1>,
> > > > > > + <&topckgen CLK_TOP_MAINPLL_D4>;
> > > > > > + clock-names = "vdec-sel", "vdec-soc-vdec", "vdec-
> > > > > > soc-
> > > > > > lat",
> > > > > > + "vdec-vdec", "vdec-top";
> > > > > > + assigned-clocks = <&topckgen CLK_TOP_VDEC_SEL>;
> > > > > > + assigned-clock-parents = <&topckgen
> > > > > > CLK_TOP_MAINPLL_D4>;
> > > > > > + power-domains = <&spm MT8192_POWER_DOMAIN_VDEC2>;
> > > > > > + };
> > > > >
> > > > > I'm a bit late in the game, reviewing v5 only, but I'm
> > > > > wondering
> > > > > if
> > > > > those IP cores need to be modelled in separate nodes. It
> > > > > would be
> > > > > much
> > > > > easier, from a software point of view, to have a single node,
> > > > > with
> > > > > multiple register ranges.
> > > > >
> > > > > Are some of those IP cores used in different SoCs, combined
> > > > > in
> > > > > different
> > > > > ways, that make a modular design better ?
> > > > >
> > > >
> > > > Different platform has different hardware, for mt8192 only has
> > > > three
> > > > nodes. but mt8195 will has five nodes. and the
> > > > clk/power/irq/iommu
> > > > are
> > > > different. It is not easy to manage all hardware at the same
> > > > time
> > > > in
> > > > one node, need to enable different hardware at the same time,
> > > > the
> > > > logic
> > > > will be very complex.
> > > > It is much easier to handle different hardware using component,
> > > > enable
> > > > different hardware when we need it.
> > > >
> > > >
> > >
> > > You can still have one device-tree node for each device, which
> > > means
> > > you can still manage your resources (clk/power/irq/iommu) easily,
> > > but
> > > doing
> > > this so that it avoids an async framework to pull the parts
> > > together.
> > >
> >
> > It mean that v4l2 async also can't be used?
>
> No, I don't think it's needed. I will take a look at the device tree
> and see if I can show you an alternative approach that doesn't
> require an async framework.
>
Thanks.
> > > I gave you this feedback several times, and you have been
> > > objecting
> > > it
> > > every time without even trying to consider a different approach.
> > >
> >
> > I'm not objecting your suggestion every time, for our driver is
> > designed for component api, need to spend a lot of time to change
> > it in
> > many platforms. We need to get a final solution for this
> > architecture,
> > or it's not easy to change all patches in the feature.
> > > Thanks,
> > > Ezequiel
> >
> > 1. Each a node should respect a HW node. Defining a complex node
> > that
> > contain multiple register is not better, for they belong to
> > different
> > hardware. Different platforms has different hardware count, mt8195
> > has
> > five hardwares.
> > 2. Another reason is from the IOMMU point, the vcodec HW include
> > core
> > and lat hardwares, each of them connect to the independent IOMMU
> > hardware for mt8195, can't write all iommu ports together, or
> > hardware
> > can't access dram data, so we must separate them.
> >
> > For these limitation, can't combine all hardware together. I will
> > write
> > the hardware diagram in next patch.
> >
>
> No need for another patch, you can write that hardware diagram
> now, so we can help with some design ideas.
>
You can see the block diagram in patch:
https://patchwork.linuxtv.org/project/linux-media/patch/20210901083215.25984-14-yunfei.dong@xxxxxxxxxxxx/
> Thanks!
> Ezequiel