Re: [PATCH v3 1/9] dt-bindings: misc: Describe TI FPC202 dual port controller

Conor Dooley
2024-11-25T18:26:42Z

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On Mon, Nov 25, 2024 at 09:45:15AM +0100, Romain Gantois wrote:
> The FPC202 dual port controller serves as a low speed signal aggregator for
> common port types, notably SFP. It provides access to I2C and low-speed
> GPIO signals of a downstream device through a single upstream control
> interface.
>
> Up to two logical I2C addresses can be accessed on each of the FPC202's
> ports. The port controller acts as an I2C translator (ATR). It converts
> addresses of incoming and outgoing I2C transactions. One use case of this
> is accessing two SFP modules at logical address 0x50 from the same upstream
> I2C controller, using two different client aliases.
>
> Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
> ---
> .../devicetree/bindings/misc/ti,fpc202.yaml | 96 ++++++++++++++++++++++
> MAINTAINERS | 6 ++
> 2 files changed, 102 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/misc/ti,fpc202.yaml b/Documentation/devicetree/bindings/misc/ti,fpc202.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..d0464a77cabed81301e27ac2fd4e7f943a027f2a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/misc/ti,fpc202.yaml
> @@ -0,0 +1,96 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/misc/ti,fpc202.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI FPC202 dual port controller with expanded IOs
> +
> +maintainers:
> + - Romain Gantois <romain.gantois@bootlin.com>
> +
> +allOf:
> + - $ref: /schemas/i2c/i2c-atr.yaml#
> +
> +properties:
> + compatible:
> + const: ti,fpc202
> +
> + reg:
> + maxItems: 1
> +
> + gpio-controller: true
> +
> + "#gpio-cells":
> + const: 2
> +
> + enable-gpios:
> + description:
> + Specifier for the GPIO connected to the EN pin.
> + maxItems: 1
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 0
> +
> +patternProperties:
> + "^i2c@[0-1]$":
> + $ref: /schemas/i2c/i2c-controller.yaml
> + description: Downstream device ports 0 and 1
> +
> + properties:
> + reg:
> + maxItems: 1
> + description:
> + Downstream port ID
> +
> + required:
> + - "#address-cells"
> + - "#size-cells"
> + - reg
> +
> + unevaluatedProperties: false
> +
> +required:
> + - compatible
> + - gpio-controller
> + - "#gpio-cells"
> + - reg
> + - "#address-cells"
> + - "#size-cells"
> + - i2c@0
> + - i2c@1

btw, why are both downstream ports required?

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