Hi Yunfei,

On Mon, Aug 30, 2021 at 02:07:44PM +0800, yunfei.dong@mediatek.com wrote:

On Sun, 2021-08-29 at 17:50 -0300, Ezequiel Garcia wrote:

quoted

On Wed, 11 Aug 2021 at 14:59, Laurent Pinchart wrote:

quoted

On Wed, Aug 11, 2021 at 10:57:59AM +0800, Yunfei Dong wrote:

quoted

Adds decoder dt-bindings for mt8192.

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
---
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@mediatek.com>
+
+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.

quoted

+
+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 ?

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.

Maybe it could help understanding the situation if the DT bindings could
include more information about the hardware architecture, such as a
block diagram for instance, and how the pieces interact with each other
?

quoted

Yeah, I agree with Laurent here. This way of modelling the different parts
of the CODEC as different pieces is the reason why you need a framework
to pull them together, such as the component API (I guess v4l2-async
could have been used as well).

We must separate each hardware node, only master need to register video
and media device, component just used for store clk/power/irq/register
information for current hardware.

quoted

I normally don't bother with driver internals, as its up to each driver
author to decide what is best. However, I believe this design is too
convoluted, and it may lead other developers to follow the same pattern,
so please avoid it.

According to your information, it looks that component and v4l2 async
are ok for this architecture, only component is too convoluted(iommu
driver also use component).

For we are not very familiar with v4l2 async, out architecture is
designed for component include next forty patches. It is a very big
change for out driver. I will try to spend a lot of time to change it.

quoted

There are several ways of modelling this and initializing or probing
the sub-devices,
without using any async framework.

You may misunderstand, 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. I will change it if v4l2 async has
many advantages then component as you said. I will try to use v4l2
async as compared.

-- 
Regards,

Laurent Pinchart

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