Re: [PATCH v11 1/3] dt-binding: mt8183: add Mediatek MDP3 dt-bindings

From: Rob Herring
Date: Fri Jan 21 2022 - 16:16:54 EST


On Wed, Jan 05, 2022 at 05:37:56PM +0800, Moudy Ho wrote:
> This patch adds DT binding document for Media Data Path 3 (MDP3)
> a unit in multimedia system used for scaling and color format convert.
>
> Signed-off-by: Moudy Ho <moudy.ho@xxxxxxxxxxxx>
> ---
> .../bindings/media/mediatek,mdp3-rdma.yaml | 193 ++++++++++++++++++
> .../bindings/media/mediatek,mdp3-rsz.yaml | 55 +++++
> .../bindings/media/mediatek,mdp3-wrot.yaml | 57 ++++++
> .../bindings/soc/mediatek/mediatek,ccorr.yaml | 47 +++++
> .../bindings/soc/mediatek/mediatek,wdma.yaml | 58 ++++++
> 5 files changed, 410 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/media/mediatek,mdp3-rdma.yaml
> create mode 100644 Documentation/devicetree/bindings/media/mediatek,mdp3-rsz.yaml
> create mode 100644 Documentation/devicetree/bindings/media/mediatek,mdp3-wrot.yaml
> create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mediatek,ccorr.yaml
> create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mediatek,wdma.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/mediatek,mdp3-rdma.yaml b/Documentation/devicetree/bindings/media/mediatek,mdp3-rdma.yaml
> new file mode 100644
> index 000000000000..002503383934
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/mediatek,mdp3-rdma.yaml
> @@ -0,0 +1,193 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/mediatek,mdp3-rdma.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Mediatek Read Direct Memory Access
> +
> +maintainers:
> + - Matthias Brugger <matthias.bgg@xxxxxxxxx>
> +
> +description: |
> + Mediatek Read Direct Memory Access(RDMA) component used to do read DMA.
> + It contains one line buffer to store the sufficient pixel data, and
> + must be siblings to the central MMSYS_CONFIG node.
> + For a description of the MMSYS_CONFIG binding, see
> + Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml
> + for details.
> + The 1st RDMA is also used to be a controller node in Media Data Path 3(MDP3)
> + that containing MMSYS, MUTEX, GCE and SCP settings.
> +
> +properties:
> + compatible:
> + oneOf:
> + - items:
> + # MDP3 controller node
> + - const: mediatek,mt8183-mdp3

How is this more specific than this:

> + - const: mediatek,mt8183-mdp3-rdma0

> + - items:
> + # normal RDMA conponent
> + - const: mediatek,mt8183-mdp3-rdma0
> +
> + mediatek,scp:
> + description: The node of system control processor (SCP), using
> + the remoteproc & rpmsg framework.
> + $ref: /schemas/types.yaml#/definitions/phandle
> + maxItems: 1
> +
> + mediatek,mdp3-comps:
> + description: MTK sub-system of direct-link or DIP

This needs a better description. What is DIP? What is direct-link?

> + $ref: /schemas/types.yaml#/definitions/string-array
> + items:
> + - enum:
> + # MDP direct-link input path selection, create a
> + # component for path connectedness of HW pipe control
> + - mediatek,mt8183-mdp3-dl1
> + - enum:
> + - mediatek,mt8183-mdp3-dl2
> + - enum:
> + # MDP direct-link output path selection, create a
> + # component for path connectedness of HW pipe control
> + - mediatek,mt8183-mdp3-path1
> + - enum:
> + - mediatek,mt8183-mdp3-path2
> + - enum:
> + # Input DMA of ISP PASS2 (DIP) module for raw image input
> + - mediatek,mt8183-mdp3-imgi
> + - enum:
> + # Output DMA of ISP PASS2 (DIP) module for YUV image output
> + - mediatek,mt8183-mdp3-exto

There's only 1 possible value for mediatek,mdp3-comps, so why does it
need to be in DT?

> +
> + reg:
> + items:
> + - description: basic RDMA HW address
> + - description: MDP direct-link 1st and 2nd input
> + - description: MDP direct-link 1st output
> + - description: MDP direct-link 2nd output
> + - description: ISP input and output
> +
> + mediatek,gce-client-reg:
> + description: The register of client driver can be configured by gce with
> + 4 arguments defined in this property, such as phandle of gce, subsys id,
> + register offset and size. Each GCE subsys id is mapping to a client
> + defined in the header include/dt-bindings/gce/<chip>-gce.h.
> + $ref: /schemas/types.yaml#/definitions/phandle-array
> + items:
> + - description: GCE client for RDMA
> + - description: GCR client for MDP direct-link 1st and 2nd input
> + - description: GCR client for MDP direct-link 1st output
> + - description: GCR client for MDP direct-link 2nd output
> + - description: GCR client for ISP input and output
> +
> + power-domains:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: RDMA clock
> + - description: RSZ clock
> + - description: direck-link TX clock in MDP side
> + - description: direck-link RX clock in MDP side
> + - description: direck-link TX clock in ISP side
> + - description: direck-link RX clock in ISP side
> +
> + iommus:
> + maxItems: 1
> +
> + mediatek,mmsys:
> + description: The node of mux(multiplexer) controller for HW connections.
> + $ref: /schemas/types.yaml#/definitions/phandle
> +
> + mediatek,mm-mutex:

Is this some sort of h/w lock? We have a standard binding for that.

> + description: The node of sof(start of frame) signal controller.
> + $ref: /schemas/types.yaml#/definitions/phandle
> + maxItems: 1
> +
> + mediatek,mailbox-gce:
> + description: The node of global command engine (GCE), used to read/write
> + registers with critical time limitation.
> + $ref: /schemas/types.yaml#/definitions/phandle
> +
> + mboxes:
> + items:
> + - description: used for 1st data pipe from RDMA
> + - description: used for 2nd data pipe from RDMA
> + - description: used for 3rd data pipe from Direct-Link
> + - description: used for 4th data pipe from Direct-Link
> +
> + gce-subsys:
> + description: sub-system id corresponding to the global command engine (GCE)
> + register address.
> + $ref: /schemas/types.yaml#/definitions/phandle-array
> +
> +if:
> + properties:
> + compatible:
> + contains:
> + const: mediatek,mt8183-mdp3
> +
> +then:
> + required:
> + - mediatek,scp
> + - mediatek,mmsys
> + - mediatek,mm-mutex
> + - mediatek,mailbox-gce
> + - mboxes
> + - gce-subsys
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - mediatek,gce-client-reg
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/mt8183-clk.h>
> + #include <dt-bindings/gce/mt8183-gce.h>
> + #include <dt-bindings/power/mt8183-power.h>
> + #include <dt-bindings/memory/mt8183-larb-port.h>
> +
> + mdp3_rdma0: mdp3_rdma0@14001000 {
> + compatible = "mediatek,mt8183-mdp3",
> + "mediatek,mt8183-mdp3-rdma0";
> + mediatek,scp = <&scp>;
> + mediatek,mdp3-comps = "mediatek,mt8183-mdp3-dl1",
> + "mediatek,mt8183-mdp3-dl2",
> + "mediatek,mt8183-mdp3-path1",
> + "mediatek,mt8183-mdp3-path2",
> + "mediatek,mt8183-mdp3-imgi",
> + "mediatek,mt8183-mdp3-exto";
> + reg = <0x14001000 0x1000>,
> + <0x14000000 0x1000>,
> + <0x14005000 0x1000>,
> + <0x14006000 0x1000>,
> + <0x15020000 0x1000>;
> + mediatek,gce-client-reg = <&gce SUBSYS_1400XXXX 0x1000 0x1000>,
> + <&gce SUBSYS_1400XXXX 0 0x1000>,
> + <&gce SUBSYS_1400XXXX 0x5000 0x1000>,
> + <&gce SUBSYS_1400XXXX 0x6000 0x1000>,
> + <&gce SUBSYS_1502XXXX 0 0x1000>;
> + power-domains = <&spm MT8183_POWER_DOMAIN_DISP>;
> + clocks = <&mmsys CLK_MM_MDP_RDMA0>,
> + <&mmsys CLK_MM_MDP_RSZ1>,
> + <&mmsys CLK_MM_MDP_DL_TXCK>,
> + <&mmsys CLK_MM_MDP_DL_RX>,
> + <&mmsys CLK_MM_IPU_DL_TXCK>,
> + <&mmsys CLK_MM_IPU_DL_RX>;
> + iommus = <&iommu>;
> + mediatek,mmsys = <&mmsys>;
> + mediatek,mm-mutex = <&mutex>;
> + mediatek,mailbox-gce = <&gce>;
> + mboxes = <&gce 20 CMDQ_THR_PRIO_LOWEST>,
> + <&gce 21 CMDQ_THR_PRIO_LOWEST>,
> + <&gce 22 CMDQ_THR_PRIO_LOWEST>,
> + <&gce 23 CMDQ_THR_PRIO_LOWEST>;
> + gce-subsys = <&gce 0x14000000 SUBSYS_1400XXXX>,
> + <&gce 0x14010000 SUBSYS_1401XXXX>,
> + <&gce 0x14020000 SUBSYS_1402XXXX>,
> + <&gce 0x15020000 SUBSYS_1502XXXX>;
> + };
> diff --git a/Documentation/devicetree/bindings/media/mediatek,mdp3-rsz.yaml b/Documentation/devicetree/bindings/media/mediatek,mdp3-rsz.yaml
> new file mode 100644
> index 000000000000..cd4cf1531535
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/mediatek,mdp3-rsz.yaml
> @@ -0,0 +1,55 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/mediatek,mdp3-rsz.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Mediatek Resizer
> +
> +maintainers:
> + - Matthias Brugger <matthias.bgg@xxxxxxxxx>
> +
> +description: |
> + One of Media Data Path 3 (MDP3) components used to do frame resizing.
> +
> +properties:
> + compatible:
> + items:
> + - enum:
> + - mediatek,mt8183-mdp3-rsz0
> + - mediatek,mt8183-mdp3-rsz1

Again, what's the difference between 0 and 1?

I've probably asked that before, but without a sufficient reasoning
here in the schema I'm just going to keep asking the same question.

Rob