Re: [PATCH 1/3] dt-bindings: dma: ti: k3-bcdma: Describe cfg register regions

[Conor Dooley]

On Thu, Aug 10, 2023 at 11:13:53PM +0530, Vignesh Raghavendra wrote:
> Block copy DMA(BCDMA)module on K3 SoCs have ring cfg, TX and RX
> channel cfg register regions which are usually configured by a Device
> Management firmware. But certain entities such as bootloader (like
> U-Boot) may have to access them directly. Describe this region in the
> binding documentation for completeness of module description.
> 
> Keep the binding compatible with existing DTS files by requiring first
> five regions to be present at least.
> 
> Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
> ---
>  .../devicetree/bindings/dma/ti/k3-bcdma.yaml  | 25 +++++++++++++------
>  1 file changed, 17 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
> index 4ca300a42a99..d166e284532b 100644
> --- a/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
> +++ b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
> @@ -37,11 +37,11 @@ properties:
>  
>    reg:
>      minItems: 3
> -    maxItems: 5
> +    maxItems: 8

How come none of these reg entries have a description? What
differentiates a "gcfg" from a "cfg" for example?

>  
>    reg-names:
>      minItems: 3
> -    maxItems: 5
> +    maxItems: 8
>  
>    "#dma-cells":
>      const: 3
> @@ -161,14 +161,19 @@ allOf:
>        properties:
>          reg:
>            minItems: 5
> +          maxItems: 8
>  
>          reg-names:
> +          minItems: 5
>            items:
>              - const: gcfg
>              - const: bchanrt
>              - const: rchanrt
>              - const: tchanrt
>              - const: ringrt
> +            - const: cfg
> +            - const: tchan
> +            - const: rchan
>  
>        required:
>          - ti,sci-rm-range-bchan
> @@ -216,12 +221,16 @@ examples:
>              main_bcdma: dma-controller@485c0100 {
>                  compatible = "ti,am64-dmss-bcdma";
>  
> -                reg = <0x0 0x485c0100 0x0 0x100>,
> -                      <0x0 0x4c000000 0x0 0x20000>,
> -                      <0x0 0x4a820000 0x0 0x20000>,
> -                      <0x0 0x4aa40000 0x0 0x20000>,
> -                      <0x0 0x4bc00000 0x0 0x100000>;
> -                reg-names = "gcfg", "bchanrt", "rchanrt", "tchanrt", "ringrt";
> +                reg = <0x00 0x485c0100 0x00 0x100>,

Why have you added extra zeros? (0x00)

Thanks,
Conor.

> +                      <0x00 0x4c000000 0x00 0x20000>,
> +                      <0x00 0x4a820000 0x00 0x20000>,
> +                      <0x00 0x4aa40000 0x00 0x20000>,
> +                      <0x00 0x4bc00000 0x00 0x100000>,
> +                      <0x00 0x48600000 0x00 0x8000>,
> +                      <0x00 0x484a4000 0x00 0x2000>,
> +                      <0x00 0x484c2000 0x00 0x2000>;
> +                reg-names = "gcfg", "bchanrt", "rchanrt", "tchanrt", "ringrt",
> +                            "cfg", "tchan", "rchan";
>                  msi-parent = <&inta_main_dmss>;
>                  #dma-cells = <3>;
>  
> -- 
> 2.41.0
>

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