Re: [PATCH v4 1/2] dt-bindings: Add support for the Broadcom UART driver

[Rob Herring <robh@kernel.org>]

On Fri, Feb 19, 2021 at 03:37:07PM -0500, Al Cooper wrote:
> Add DT bindings for the Broadcom 8250 based UART driver. This
> UART is based on an 8250 but adds additional functionality. The
> additional features include the ability to use DMA for transfers and
> a baud rate clock system that is more accurate at high baud rates.
> This UART is backward compatible with the standard 8250 UART.
> 
> Signed-off-by: Al Cooper <alcooperx@gmail.com>
> ---
>  .../bindings/serial/brcm,bcm7271-uart.yaml    | 96 +++++++++++++++++++
>  1 file changed, 96 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/serial/brcm,bcm7271-uart.yaml
> 
> diff --git a/Documentation/devicetree/bindings/serial/brcm,bcm7271-uart.yaml b/Documentation/devicetree/bindings/serial/brcm,bcm7271-uart.yaml
> new file mode 100644
> index 000000000000..f3d58e613480
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/serial/brcm,bcm7271-uart.yaml
> @@ -0,0 +1,96 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/serial/brcm,bcm7271-uart.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Broadcom 8250 based serial port devicetree bindings
> +
> +maintainers:
> +  - Al Cooper <alcooperx@gmail.com>
> +
> +description: |+
> +  The Broadcom UART is based on the basic 8250 UART but with
> +  enhancements for more accurate high speed baud rates and support
> +  for DMA.
> +
> +properties:
> +  $nodename:
> +    pattern: "^serial@[0-9a-f]+$"

Reference serial.yaml and you can drop this (and have slave devices).

You'll need to use 'unevaluatedProperties' instead of 
'additionalProperties' as well.

> +
> +  compatible:
> +    items:
> +      - enum:
> +          - brcm,bcm7271-uart
> +          - brcm,bcm7278-uart

Blank line.

> +  reg:
> +    minItems: 1
> +    maxItems: 5
> +
> +  reg-names:
> +    description: The UART register block and optionally the DMA register blocks.
> +    oneOf:
> +      - items:
> +          - const: uart
> +      - items:
> +          - const: uart
> +          - const: dma_arb
> +          - const: dma_rx
> +          - const: dma_tx
> +          - const: dma_intr2
> +
> +  clocks:
> +    minItems: 1
> +
> +  clock-names:
> +    const: sw_baud
> +
> +  interrupts:
> +    minItems: 1
> +    maxItems: 2
> +
> +  interrupt-names:
> +    description: The UART interrupt and optionally the DMA interrupt.
> +    oneOf:
> +      - items:
> +          - const: uart
> +      - items:
> +          - const: uart
> +          - const: dma

Drop the oneOf and add 'minItems: 1'.

> +
> +required:
> +  - compatible
> +  - reg
> +  - reg-names
> +  - clocks
> +  - clock-names
> +  - interrupts
> +  - interrupt-names
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    serial@840d000 {
> +        compatible = "brcm,bcm7271-uart";
> +        reg = <0x840d000 0x20>;
> +        reg-names = "uart";
> +        interrupts = <0x0 0x62 0x4>;
> +        interrupt-names = "uart";
> +        clocks = <&scmi_clk 190>;
> +        clock-names = "sw_baud";
> +    };
> +
> +    serial@840e000 {
> +        compatible = "brcm,bcm7271-uart";
> +        reg = <0x840e000 0x20>,
> +              <0x840e080 0x8>,
> +              <0x840e100 0xa8>,
> +              <0x840e200 0x4c>,
> +              <0x840e300 0x30>;
> +        reg-names = "uart", "dma_arb", "dma_rx", "dma_tx", "dma_intr2";
> +        interrupts = <0x0 0x62 0x4>, <0x0 0x75 0x4>;
> +        interrupt-names = "uart", "dma";
> +        clocks = <&scmi_clk 190>;
> +        clock-names = "sw_baud";
> +    };
> -- 
> 2.17.1
>