Re: [PATCH 2/3] dt-bindings: fpga: Add Efinix serial SPI programming binding description

[Conor Dooley <conor@kernel.org>]

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On Thu, Jun 20, 2024 at 04:44:40PM +0200, iansdannapel@gmail.com wrote:
> From: Ian Dannapel <iansdannapel@gmail.com>
> 
> Add device tree binding documentation for configuring Efinix FPGA
> using serial SPI passive programming mode.
> 
> Signed-off-by: Ian Dannapel <iansdannapel@gmail.com>
> ---
>  .../bindings/fpga/efnx,fpga-passive-spi.yaml  | 76 +++++++++++++++++++
>  1 file changed, 76 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/fpga/efnx,fpga-passive-spi.yaml
> 
> diff --git a/Documentation/devicetree/bindings/fpga/efnx,fpga-passive-spi.yaml b/Documentation/devicetree/bindings/fpga/efnx,fpga-passive-spi.yaml
> new file mode 100644
> index 000000000000..855ceb3b89e8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/fpga/efnx,fpga-passive-spi.yaml
> @@ -0,0 +1,76 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/fpga/efnx,fpga-passive-spi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Efinix SPI FPGA Manager
> +
> +description: |
> +  Efinix Trion and Titanium Series FPGAs support a method of loading the
> +  bitstream over what is referred to as "SPI Passive Programming".
> +  Only serial (1x bus width) is supported, setting the programming mode
> +  is not in the scope the this manager and must be done elsewhere.
> +
> +  References:
> +  - https://www.efinixinc.com/docs/an033-configuring-titanium-fpgas-v2.6.pdf
> +  - https://www.efinixinc.com/docs/an006-configuring-trion-fpgas-v6.0.pdf
> +
> +allOf:
> +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      - efnx,fpga-spi-passive

Ahh, here is the user. Can you please add specific compatibles for the
Trion and Titanium series FPGAs? And when you do, make the filename
match a compatible please.

Additionally, why "efnx" and not "efinix"?

> +
> +  spi-cpha: true
> +  spi-cpol: true
> +
> +  spi-max-frequency:
> +    maximum: 25000000
> +
> +  reg:
> +    maxItems: 1
> +
> +  reset-gpios:
> +    description:
> +      reset pin (low active)
> +    maxItems: 1
> +
> +  cs-gpios:
> +    description:
> +      chip-select pin (low active)
> +    maxItems: 1
> +
> +  done-gpios:
> +    description:
> +      optional programming done pin, referred as CDONE (high active)

Why not call it "cdone-gpios" if that;s what it is referred to as?

> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - reset-gpios
> +  - cs-gpios
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    &spi2 {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      fpga_mgr_spi: fpga-mgr@0 {
> +        compatible = "efnx,fpga-spi-passive";
> +        spi-max-frequency = <25000000>;
> +        spi-cpha;
> +        spi-cpol;
> +        reg = <0>;

order of compatible, reg, others here please.

> +        reset-gpios = <&gpio4 17 GPIO_ACTIVE_LOW>;
> +        cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
> +        done-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
> +      };
> +    };
> +...
> -- 
> 2.34.1
> 

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