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

From: Rob Herring
Date: Mon Mar 11 2019 - 18:59:09 EST


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@xxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx
> ---
> .../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@xxxxxx>
> 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
>