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

Conor Dooley
2024-11-08T18:23:43Z

[-- Attachment #1: Type: text/plain, Size: 3488 bytes --]

On Fri, Nov 08, 2024 at 04:36:53PM +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 | 75 ++++++++++++++++++++++
> 1 file changed, 75 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..ad11abe11e68aa266acdd6b43a5b425340bbbba8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/misc/ti,fpc202.yaml
> @@ -0,0 +1,75 @@
> +# 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#

Gotta say, this looks absolutely nothing like the other i2c-atr user!

> +
> +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
> +
> + port0:

ports usually go in a ports node, and are port@0 not port0. That said,
these are i2c buses, so the node name would usually be i2c@ for those.
In fact, given you have i2c-mux as your node name, the binding for that
expects you to format your child nodes like '^i2c@[0-9a-f]+$'. Is there
a reason you can't just drop this ports business and go with a pattern
property here that restricts the pattern to '^i2c@[0-1]$'?

> + $ref: /schemas/i2c/i2c-controller.yaml
> + description:
> + Device port 0, accessible over I2C.
> +
> + port1:
> + $ref: /schemas/i2c/i2c-controller.yaml
> + description:
> + Device port 1, accessible over I2C.
> +
> +
> +required:
> + - compatible
> + - gpio-controller
> + - "#gpio-cells"
> + - reg
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + i2c {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + fpc202: i2c-mux@f {

The label here is uused, you should drop it.

Cheers,
Conor.

> + compatible = "ti,fpc202";
> + reg = <0xf>;
> +
> + gpio-controller;
> + #gpio-cells = <2>;
> +
> + port0 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + };
> +
> + port1 {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + };
> + };
> + };
> +...
>
> --
> 2.47.0
>

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]