Re: [PATCH v4 armsoc/drivers/bus+gpio 2/5] dt-bindings: bus: Document moxtet bus binding

[Rob Herring <robh@kernel.org>]

On Thu, Mar 07, 2019 at 01:52:48PM +0100, Marek Behún wrote:
> This adds device tree binding documentation for the Moxtet bus, a bus
> via which the different modules connected to the Turris Mox router can
> be configured.
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../devicetree/bindings/bus/moxtet.txt        | 44 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 45 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/moxtet.txt
> 
> diff --git a/Documentation/devicetree/bindings/bus/moxtet.txt b/Documentation/devicetree/bindings/bus/moxtet.txt
> new file mode 100644
> index 000000000000..7be9d00c1767
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/moxtet.txt
> @@ -0,0 +1,44 @@
> +Turris Mox module status and configuration bus (over SPI)
> +
> +Required properties:
> + - compatible		: Should be "cznic,moxtet"
> + - #address-cells	: Has to be 1
> + - #size-cells		: Has to be 0
> + - spi-cpol		: Required inverted clock polarity
> + - spi-cpha		: Required shifted clock phase
> + - interrupts		: Must contain reference to the shared interrupt line
> + - interrupt-controller	: Required
> + - #interrupt-cells	: Has to be 1
> +
> +For other required and optional properties of SPI slave nodes please refer to
> +../spi/spi-bus.txt.
> +
> +Required properties of subnodes:
> + - reg			: Should be position on the Moxtet bus

'position' is a little vague.

> +
> +The driver finds the devices connected to the bus by itself, but it may be
> +needed to reference some of them from other parts of the device tree. In that
> +case the devices can be defined as subnodes of the moxtet node.
> +
> +Example:
> +
> +	moxtet@1 {
> +		compatible = "cznic,moxtet";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		reg = <1>;
> +		spi-max-frequency = <10000000>;
> +		spi-cpol;
> +		spi-cpha;
> +		interrupt-controller;
> +		#interrupt-cells = <1>;
> +		interrupt-parent = <&gpiosb>;
> +		interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
> +
> +		moxtet_sfp: gpio@0 {
> +			compatible = "cznic,moxtet-sfp";

cznic,moxtet-gpio according to the next patch.

> +			gpio-controller;
> +			#gpio-cells = <2>;
> +			reg = <0>;
> +		}
> +	};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d96d36c83bc3..3f461a2d776a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1502,6 +1502,7 @@ ARM/CZ.NIC TURRIS MOX SUPPORT
>  M:	Marek Behun <marek.behun@nic.cz>
>  W:	http://mox.turris.cz
>  S:	Maintained
> +F:	Documentation/devicetree/bindings/bus/moxtet.txt
>  F:	include/linux/moxtet.h
>  F:	drivers/bus/moxtet.c
>  
> -- 
> 2.19.2
>