Re: [PATCH v4 1/4] dt-bindings: dmaengine: Add MediaTek Command-Queue DMA controller bindings

[EastL <EastL.Lee@xxxxxxxxxxxx>]

On Fri, 2020-05-29 at 13:24 -0600, Rob Herring wrote:
> On Thu, May 28, 2020 at 05:57:09PM +0800, EastL wrote:
> > Document the devicetree bindings for MediaTek Command-Queue DMA controller
> > which could be found on MT6779 SoC or other similar Mediatek SoCs.
> > 
> > Signed-off-by: EastL <EastL.Lee@xxxxxxxxxxxx>
> 
> Need a full name

OK
> .
> 
> > ---
> >  .../devicetree/bindings/dma/mtk-cqdma.yaml         | 100 +++++++++++++++++++++
> >  1 file changed, 100 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/dma/mtk-cqdma.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/dma/mtk-cqdma.yaml b/Documentation/devicetree/bindings/dma/mtk-cqdma.yaml
> > new file mode 100644
> > index 0000000..045aa0c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/dma/mtk-cqdma.yaml
> > @@ -0,0 +1,100 @@
> > +# SPDX-License-Identifier: GPL-2.0
> 
> Dual license new bindings:
> 
> (GPL-2.0-only OR BSD-2-Clause)

OK
> 
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/dma/mtk-cqdma.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: MediaTek Command-Queue DMA controller Device Tree Binding
> > +
> > +maintainers:
> > +  - EastL <EastL.Lee@xxxxxxxxxxxx>
> > +
> > +description:
> > +  MediaTek Command-Queue DMA controller (CQDMA) on Mediatek SoC
> > +  is dedicated to memory-to-memory transfer through queue based
> > +  descriptor management.
> > +
> 
> Need a $ref to dma-controller.yaml

OK
> 
> > +properties:
> > +  "#dma-cells":
> > +    minimum: 1
> > +    # Should be enough
> > +    maximum: 255
> > +    description:
> > +      Used to provide DMA controller specific information.
> > +
> > +  compatible:
> > +    const: mediatek,cqdma
> 
> Needs SoC specific compatible string(s).
OK
> 
> > +
> > +  reg:
> > +    minItems: 1
> > +    maxItems: 255
> 
> You can have 255 register regions?
No, I'll fix maxItems to 5
> 
> You need to define what each region is if more than 1.
> 
> > +
> > +  interrupts:
> > +    minItems: 1
> > +    maxItems: 255
> 
> 255 interrupts?

the same, 5 interripts.
> 
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  clock-names:
> > +    const: cqdma
> > +
> > +  dma-channel-mask:
> > +    description:
> > +      Bitmask of available DMA channels in ascending order that are
> > +      not reserved by firmware and are available to the
> > +      kernel. i.e. first channel corresponds to LSB.
> > +      The first item in the array is for channels 0-31, the second is for
> > +      channels 32-63, etc.
> > +    allOf:
> > +      - $ref: /schemas/types.yaml#/definitions/uint32-array
> > +    items:
> > +      minItems: 1
> > +      # Should be enough
> > +      maxItems: 255
> 
> This already has a definition in dma-common.yaml. Don't copy-n-paste 
> it. Just add any constraints you have. Like what is the max number of 
> channels?

OK, the max channel number is 5, I'll fix it on next version.
> 
> > +
> > +  dma-channels:
> > +    $ref: /schemas/types.yaml#definitions/uint32
> > +    description:
> > +      Number of DMA channels supported by the controller.
> > +
> > +  dma-requests:
> > +    $ref: /schemas/types.yaml#definitions/uint32
> > +    description:
> > +      Number of DMA request signals supported by the controller.
> 
> Same comment on these 2.

OK
> 
> > +
> > +required:
> > +  - "#dma-cells"
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - clocks
> > +  - clock-names
> > +  - dma-channel-mask
> > +  - dma-channels
> > +  - dma-requests
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/clock/mt6779-clk.h>
> > +    cqdma: dma-controller@10212000 {
> > +        compatible = "mediatek,cqdma";
> > +        reg = <0 0x10212000 0 0x80>,
> > +            <0 0x10212080 0 0x80>,
> > +            <0 0x10212100 0 0x80>;
> 
> Examples default to 1 cell each for address and size.
OK
> 
> > +        interrupts = <GIC_SPI 139 IRQ_TYPE_LEVEL_LOW>,
> > +            <GIC_SPI 140 IRQ_TYPE_LEVEL_LOW>,
> > +            <GIC_SPI 141 IRQ_TYPE_LEVEL_LOW>;
> > +        clocks = <&infracfg_ao CLK_INFRA_CQ_DMA>;
> > +        clock-names = "cqdma";
> > +        dma-channel-mask = <63>;
> > +        dma-channels = <3>;
> > +        dma-requests = <32>;
> > +        #dma-cells = <1>;
> > +    };
> > +
> > +...
> > -- 
> > 1.9.1