Re: [PATCH v10 1/7] dt-bindings: soc: Add Aspeed XDMA Engine

[Rob Herring <robh@kernel.org>]

On Mon, Apr 20, 2020 at 03:26:05PM -0500, Eddie James wrote:
> Document the bindings for the Aspeed AST25XX and AST26XX XDMA engine.
> 
> Signed-off-by: Eddie James <eajames@linux.ibm.com>
> Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
> ---
>  .../devicetree/bindings/soc/aspeed/xdma.yaml  | 108 ++++++++++++++++++
>  MAINTAINERS                                   |   6 +
>  2 files changed, 114 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/aspeed/xdma.yaml
> 
> diff --git a/Documentation/devicetree/bindings/soc/aspeed/xdma.yaml b/Documentation/devicetree/bindings/soc/aspeed/xdma.yaml
> new file mode 100644
> index 000000000000..428a575da1be
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/aspeed/xdma.yaml
> @@ -0,0 +1,108 @@
> +# SPDX-License-Identifier: (GPL-2.0-or-later)

Dual license new bindings please:

(GPL-2.0-only OR BSD-2-Clause)

> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/soc/aspeed/xdma.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Aspeed AST25XX and AST26XX XDMA Engine
> +
> +maintainers:
> + - Eddie James <eajames@linux.ibm.com>
> +
> +description: |
> +  This binding describes the XDMA Engine embedded in the AST2500 and AST2600
> +  SOCs. The XDMA engine can perform automatic DMA operations over PCI between
> +  the SOC (acting as a BMC) and a host processor.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - aspeed,ast2500-xdma
> +      - aspeed,ast2600-xdma
> +
> +  reg:
> +    items:
> +      - description: engine register space

That's all 'reg' properties. You don't need a description for a 
single entry. Just:

reg:
  maxItems: 1

> +
> +  clocks:
> +    maxItems: 1
> +
> +  resets:
> +    minItems: 1
> +    maxItems: 2
> +
> +  reset-names:
> +    maxItems: 2
> +    items:
> +      - const: device
> +      - const: root-complex
> +
> +  interrupts-extended:

Just use 'interrupts'. The tools fix things up so both work.

> +    maxItems: 2
> +    items:
> +      - description: global interrupt for the XDMA engine
> +      - description: PCI-E reset or PERST interrupt
> +
> +  aspeed,scu:
> +    description: a reference to the System Control Unit node of the Aspeed SOC.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/phandle
> +
> +  aspeed,pcie-device:
> +    description: describes which PCI-E device the XDMA engine should use
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/string
> +      - oneOf:
> +        - items:
> +          - const: bmc
> +        - items:
> +          - const: vga

The oneOf (inclusive) can be just:

enum: [ bmc, vga ]

> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - resets
> +  - interrupts-extended
> +  - aspeed,scu
> +  - memory-region
> +
> +if:
> +  properties:
> +    compatible:
> +      contains:
> +        const: aspeed,ast2600-xdma
> +then:
> +  required:
> +    - reset-names
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/ast2600-clock.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/interrupt-controller/aspeed-scu-ic.h>
> +    syscon: syscon@1e6e2000 {
> +        reg = <0x1e6e2000 0x1000>;
> +        ranges = <0 0x1e6e2000 0x1000>;
> +        #address-cells = <1>;
> +        #size-cells = <1>;
> +        #clock-cells = <1>;
> +        #reset-cells = <1>;
> +        scu_ic0: interrupt-controller@560 {
> +            reg = <0x560 0x4>;
> +            interrupt-controller;
> +            #interrupt-cells = <1>;
> +        };
> +    };
> +    xdma@1e6e7000 {
> +        compatible = "aspeed,ast2600-xdma";
> +        reg = <0x1e6e7000 0x100>;
> +        clocks = <&syscon ASPEED_CLK_GATE_BCLK>;
> +        resets = <&syscon ASPEED_RESET_DEV_XDMA>, <&syscon ASPEED_RESET_RC_XDMA>;
> +        reset-names = "device", "root-complex";
> +        interrupts-extended = <&gic GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
> +                              <&scu_ic0 ASPEED_AST2600_SCU_IC0_PCIE_PERST_LO_TO_HI>;
> +        aspeed,scu = <&syscon>;
> +        aspeed,pcie-device = "bmc";
> +        memory-region = <&vga_memory>;
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index ecd7def6ff4b..b1963e01a75e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2774,6 +2774,12 @@ S:	Maintained
>  F:	Documentation/devicetree/bindings/media/aspeed-video.txt
>  F:	drivers/media/platform/aspeed-video.c
>  
> +ASPEED XDMA ENGINE DRIVER
> +M:	Eddie James <eajames@linux.ibm.com>
> +L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/soc/aspeed/xdma.yaml
> +
>  ASUS NOTEBOOKS AND EEEPC ACPI/WMI EXTRAS DRIVERS
>  M:	Corentin Chary <corentin.chary@gmail.com>
>  L:	acpi4asus-user@lists.sourceforge.net
> -- 
> 2.24.0
>