Re: [PATCH v5, 13/15] dt-bindings: media: mtk-vcodec: Adds decoder dt-bindings for mt8192
From: yunfei.dong@xxxxxxxxxxxx
Date: Tue Aug 31 2021 - 23:49:27 EST
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?
> 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.
Thanks,
Yunfei Dong