Re: [PATCH v11 04/14] dt-bindings: Add bindings document of Aspeed PECI adapter

[Rob Herring <robh@kernel.org>]

On Wed, Dec 11, 2019 at 11:46:14AM -0800, Jae Hyun Yoo wrote:
> This commit adds bindings document of Aspeed PECI adapter for ASPEED
> AST24xx/25xx/26xx SoCs.
> 
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Joel Stanley <joel@jms.id.au>
> Cc: Andrew Jeffery <andrew@aj.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jason M Biils <jason.m.bills@linux.intel.com>
> Cc: Milton Miller II <miltonm@us.ibm.com>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Robin Murphy <robin.murphy@arm.com>
> Cc: Ryan Chen <ryan_chen@aspeedtech.com>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> ---
> Changes since v10:
> - Changed documents format to DT schema format so I dropped all review tags.
>   Please review it again.
> 
>  .../devicetree/bindings/peci/peci-aspeed.yaml | 124 ++++++++++++++++++
>  1 file changed, 124 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/peci/peci-aspeed.yaml
> 
> diff --git a/Documentation/devicetree/bindings/peci/peci-aspeed.yaml b/Documentation/devicetree/bindings/peci/peci-aspeed.yaml
> new file mode 100644
> index 000000000000..0f5c2993fe9b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/peci/peci-aspeed.yaml
> @@ -0,0 +1,124 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/peci/peci-aspeed.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Aspeed PECI Bus Device Tree Bindings
> +
> +maintainers:
> +  - Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - aspeed,ast2400-peci
> +      - aspeed,ast2500-peci
> +      - aspeed,ast2600-peci
> +
> +  reg:
> +    maxItems: 1
> +

> +  "#address-cells":
> +    # Required to define a client address.
> +    const: 1
> +
> +  "#size-cells":
> +    # Required to define a client address.
> +    const: 0

These 2 can be defined by the bus schema.

> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    description: |

You can drop the '|' if there's no formatting to preserve.

> +      Clock source for PECI controller. Should reference the external
> +      oscillator clock.
> +    maxItems: 1
> +
> +  resets:
> +    maxItems: 1
> +
> +  clock-frequency:
> +    # Operation frequency of PECI controller in units of Hz.
> +    minimum: 187500
> +    maximum: 24000000
> +
> +  msg-timing:
> +    description: |
> +      Message timing negotiation period. This value will determine the period
> +      of message timing negotiation to be issued by PECI controller. The unit
> +      of the programmed value is four times of PECI clock period.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - minimum: 0
> +        maximum: 255
> +        default: 1
> +
> +  addr-timing:
> +    description: |
> +      Address timing negotiation period. This value will determine the period
> +      of address timing negotiation to be issued by PECI controller. The unit
> +      of the programmed value is four times of PECI clock period.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - minimum: 0
> +        maximum: 255
> +        default: 1
> +
> +  rd-sampling-point:
> +    description: |
> +      Read sampling point selection. The whole period of a bit time will be
> +      divided into 16 time frames. This value will determine the time frame
> +      in which the controller will sample PECI signal for data read back.
> +      Usually in the middle of a bit time is the best.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - minimum: 0
> +        maximum: 15
> +        default: 8
> +
> +  cmd-timeout-ms:
> +    # Command timeout in units of ms.
> +    allOf:
> +      - $ref: /schemas/types.yaml#/definitions/uint32
> +      - minimum: 1
> +        maximum: 60000
> +        default: 1000
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#address-cells"
> +  - "#size-cells"
> +  - interrupts
> +  - clocks
> +  - resets
> +  - clock-frequency
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/clock/ast2600-clock.h>
> +    peci: bus@1e78b000 {
> +        compatible = "simple-bus";
> +        #address-cells = <1>;
> +        #size-cells = <1>;
> +        ranges = <0x0 0x1e78b000 0x60>;

You can drop this node in the examples.

> +
> +        peci0: peci-bus@0 {
> +            compatible = "aspeed,ast2600-peci";
> +            reg = <0x0 0x100>;
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +            interrupts = <GIC_SPI 38 IRQ_TYPE_LEVEL_HIGH>;
> +            clocks = <&syscon ASPEED_CLK_GATE_REF0CLK>;
> +            resets = <&syscon ASPEED_RESET_PECI>;
> +            clock-frequency = <24000000>;
> +            msg-timing = <1>;
> +            addr-timing = <1>;
> +            rd-sampling-point = <8>;
> +            cmd-timeout-ms = <1000>;
> +        };
> +    };
> +...
> -- 
> 2.17.1
>