Re: [PATCH] dt-bindings: dma: img-mdc-dma: convert to DT schema

[Rob Herring <robh@kernel.org>]

On Thu, Aug 21, 2025 at 11:02:55PM +0800, Nino Zhang wrote:
> Convert the img-mdc-dma binding from txt to YAML schema.
> No functional changes except dropping the consumer node
> (spi@18100f00) from the example, which belongs to the
> consumer binding instead.
> 
> Tested with 'make dt_binding_check'.

No need to say that in the commit msg. It is assumed you did this.

> 
> Signed-off-by: Nino Zhang <ninozhang001@gmail.com>
> ---
>  .../devicetree/bindings/dma/img-mdc-dma.txt   | 57 -----------
>  .../devicetree/bindings/dma/img-mdc-dma.yaml  | 98 +++++++++++++++++++
>  2 files changed, 98 insertions(+), 57 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/dma/img-mdc-dma.txt
>  create mode 100644 Documentation/devicetree/bindings/dma/img-mdc-dma.yaml
> 
> diff --git a/Documentation/devicetree/bindings/dma/img-mdc-dma.txt b/Documentation/devicetree/bindings/dma/img-mdc-dma.txt
> deleted file mode 100644
> index 28c1341db346..000000000000
> --- a/Documentation/devicetree/bindings/dma/img-mdc-dma.txt
> +++ /dev/null
> @@ -1,57 +0,0 @@
> -* IMG Multi-threaded DMA Controller (MDC)
> -
> -Required properties:
> -- compatible: Must be "img,pistachio-mdc-dma".
> -- reg: Must contain the base address and length of the MDC registers.
> -- interrupts: Must contain all the per-channel DMA interrupts.
> -- clocks: Must contain an entry for each entry in clock-names.
> -  See ../clock/clock-bindings.txt for details.
> -- clock-names: Must include the following entries:
> -  - sys: MDC system interface clock.
> -- img,cr-periph: Must contain a phandle to the peripheral control syscon
> -  node which contains the DMA request to channel mapping registers.
> -- img,max-burst-multiplier: Must be the maximum supported burst size multiplier.
> -  The maximum burst size is this value multiplied by the hardware-reported bus
> -  width.
> -- #dma-cells: Must be 3:
> -  - The first cell is the peripheral's DMA request line.
> -  - The second cell is a bitmap specifying to which channels the DMA request
> -    line may be mapped (i.e. bit N set indicates channel N is usable).
> -  - The third cell is the thread ID to be used by the channel.
> -
> -Optional properties:
> -- dma-channels: Number of supported DMA channels, up to 32.  If not specified
> -  the number reported by the hardware is used.
> -
> -Example:
> -
> -mdc: dma-controller@18143000 {
> -	compatible = "img,pistachio-mdc-dma";
> -	reg = <0x18143000 0x1000>;
> -	interrupts = <GIC_SHARED 27 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 28 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 29 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 30 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 31 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 32 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 33 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 34 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 35 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 36 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 37 IRQ_TYPE_LEVEL_HIGH>,
> -		     <GIC_SHARED 38 IRQ_TYPE_LEVEL_HIGH>;
> -	clocks = <&system_clk>;
> -	clock-names = "sys";
> -
> -	img,max-burst-multiplier = <16>;
> -	img,cr-periph = <&cr_periph>;
> -
> -	#dma-cells = <3>;
> -};
> -
> -spi@18100f00 {
> -	...
> -	dmas = <&mdc 9 0xffffffff 0>, <&mdc 10 0xffffffff 0>;
> -	dma-names = "tx", "rx";
> -	...
> -};
> diff --git a/Documentation/devicetree/bindings/dma/img-mdc-dma.yaml b/Documentation/devicetree/bindings/dma/img-mdc-dma.yaml
> new file mode 100644
> index 000000000000..b635125d7ae3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/img-mdc-dma.yaml

Use the compatible string for the filename.

> @@ -0,0 +1,98 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/img-mdc-dma.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: IMG Multi-threaded DMA Controller (MDC)
> +
> +maintainers:
> +  - Vinod Koul <vkoul@kernel.org>

No, must be someone with this h/w and cares about this h/w.

> +
> +allOf:
> +  - $ref: /schemas/dma/dma-controller.yaml#
> +
> +properties:
> +  compatible:
> +    description: Must be "img,pistachio-mdc-dma".

Drop. The schema says that. Same goes for all the other descriptions, so 
I won't repeat it everywhere.

> +    const: img,pistachio-mdc-dma
> +
> +  reg:
> +    description:
> +      Must contain the base address and length of the MDC registers.

Drop.

> +    minItems: 1

maxItems instead.

> +
> +  interrupts:
> +    description:
> +      Must contain all the per-channel DMA interrupts.

Must define how many.

> +
> +  clocks:
> +    description: |
> +      Must contain an entry for each entry in clock-names.
> +      See clock/clock.yaml for details.

Drop.

Must define how many clocks and what they are.

> +
> +  clock-names:
> +    description: |
> +      Must include the following entries:
> +        - sys: MDC system interface clock.

Drop. The schema says that.

> +    minItems: 1
> +    contains: { const: sys }

Must be exact list of values, not 'sys' plus anything else you want.

> +
> +  img,cr-periph:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description: |

Drop '|'. Not needed if no formatting to maintain.


> +      Must contain a phandle to the peripheral control syscon node
> +      which contains the DMA request to channel mapping registers.
> +
> +  img,max-burst-multiplier:
> +    description: |
> +      Must be the maximum supported burst size multiplier.
> +      The maximum burst size is this value multiplied by the
> +      hardware-reported bus width.

Wrap lines at 80 and drop '|'.

> +    $ref: /schemas/types.yaml#/definitions/uint32

constraints?

> +
> +  "#dma-cells":
> +    description: |
> +      Must be 3:
> +        - The first cell is the peripheral's DMA request line.
> +        - The second cell is a bitmap specifying to which channels the DMA request
> +          line may be mapped (i.e. bit N set indicates channel N is usable).
> +        - The third cell is the thread ID to be used by the channel.
> +    const: 3
> +
> +  dma-channels:
> +    description: |
> +      Number of supported DMA channels, up to 32. If not specified
> +      the number reported by the hardware is used.
> +    $ref: /schemas/types.yaml#/definitions/uint32

Drop. Already has a type defined.

> +    maximum: 32
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - "img,cr-periph"
> +  - "img,max-burst-multiplier"

Don't need quotes.

> +  - "#dma-cells"
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/mips-gic.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    mdc: dma-controller@18143000 {

Drop 'mdc'

> +      compatible = "img,pistachio-mdc-dma";
> +      reg = <0x18143000 0x1000>;
> +      interrupts = <GIC_SHARED 27 IRQ_TYPE_LEVEL_HIGH>,
> +            <GIC_SHARED 28 IRQ_TYPE_LEVEL_HIGH>;
> +      clocks = <&system_clk>;
> +      clock-names = "sys";
> +
> +      img,max-burst-multiplier = <16>;
> +      img,cr-periph = <&cr_periph>;
> +
> +      #dma-cells = <3>;
> +    };
> -- 
> 2.43.0
>