Re: [PATCH v5 3/4] dt: bindings: dma: Add DT bindings for HiSilicon Hiedma Controller

[Rob Herring <robh@kernel.org>]

On Thu, Nov 19, 2020 at 08:01:28PM +0000, Dongjiu Geng wrote:
> The Hiedma Controller v310 Provides eight DMA channels, each
> channel can be configured for one-way transfer. The data can
> be transferred in 8-bit, 16-bit, 32-bit, or 64-bit mode. This
> documentation describes DT bindings of this controller.
> 
> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
> ---
>  .../bindings/dma/hisilicon,hiedmacv310.yaml   | 103 ++++++++++++++++++
>  1 file changed, 103 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/hisilicon,hiedmacv310.yaml
> 
> diff --git a/Documentation/devicetree/bindings/dma/hisilicon,hiedmacv310.yaml b/Documentation/devicetree/bindings/dma/hisilicon,hiedmacv310.yaml
> new file mode 100644
> index 000000000000..fe5c5af4d3e1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/hisilicon,hiedmacv310.yaml
> @@ -0,0 +1,103 @@
> +# SPDX-License-Identifier:  GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/dma/hisilicon,hiedmacv310.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: HiSilicon Hiedma Controller v310 Device Tree Bindings
> +
> +description: |
> +  These bindings describe the DMA engine included in the HiSilicon Hiedma
> +  Controller v310 Device.
> +
> +maintainers:
> +  - Dongjiu Geng <gengdongjiu@huawei.com>
> +
> +allOf:
> +  - $ref: "dma-controller.yaml#"
> +
> +properties:
> +  "#dma-cells":
> +    const: 2
> +
> +  "#clock-cells":
> +    const: 2

The DMA controller is a clock provider? Odd. What does each cell 
represent?

> +
> +  compatible:
> +    const: hisilicon,hiedmacv310
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  misc_regmap:
> +    description: phandle pointing to the misc controller provider node.
> +
> +  misc_ctrl_base:
> +    maxItems: 1

These 2 can be a single property with phandle + reg offset.

Also, needs a vendor prefix and don't use '_'.

> +
> +  clocks:
> +    items:
> +      - description: apb clock
> +      - description: axi clock
> +
> +  clock-names:
> +    items:
> +      - const: apb_pclk
> +      - const: axi_aclk
> +
> +  resets:
> +    description: phandle pointing to the dma reset controller provider node.
> +
> +  reset-names:
> +    items:
> +      - const: dma-reset
> +
> +  dma-requests:
> +    maximum: 32
> +
> +  dma-channels:
> +    maximum: 8
> +
> +
> +required:
> +  - "#dma-cells"
> +  - "#clock-cells"
> +  - compatible
> +  - misc_regmap
> +  - misc_ctrl_base
> +  - reg
> +  - interrupts
> +  - clocks
> +  - clock-names
> +  - resets
> +  - reset-names
> +  - dma-requests
> +  - dma-channels
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/clock/hi3559av100-clock.h>
> +
> +    dma: dma-controller@10040000 {
> +      compatible = "hisilicon,hiedmacv310";
> +      reg = <0x10040000 0x1000>;
> +      misc_regmap = <&misc_ctrl>;
> +      misc_ctrl_base = <0x144>;
> +      interrupts = <0 82 4>;
> +      clocks = <&clock HI3559AV100_EDMAC1_CLK>, <&clock HI3559AV100_EDMAC1_AXICLK>;
> +      clock-names = "apb_pclk", "axi_aclk";
> +      #clock-cells = <2>;
> +      resets = <&clock 0x16c 7>;
> +      reset-names = "dma-reset";
> +      dma-requests = <32>;
> +      dma-channels = <8>;
> +      #dma-cells = <2>;
> +    };
> +
> +...
> -- 
> 2.17.1
>