Re: [PATCH anybus v4 6/7] dt-bindings: anybuss-host: document devicetree binding

[Rob Herring <robh@kernel.org>]

On Wed, Nov 21, 2018 at 10:07:08AM -0500, thesven73@gmail.com wrote:
> This patch adds devicetree binding documentation for the
> Arcx Anybus-S host.
> 
> Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
> ---
>  .../bindings/fieldbus/arcx,anybuss-host.txt   | 66 +++++++++++++++++++
>  1 file changed, 66 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
> 
> diff --git a/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt b/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
> new file mode 100644
> index 000000000000..456587f288c1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
> @@ -0,0 +1,66 @@
> +* Arcx Anybus-S host
> +
> +This host communicates with the SoC over a parallel bus. It is
> +expected that its Device Tree node is specified as the child of a node
> +corresponding to the parallel bus used for communication.
> +
> +Required properties:
> +--------------------
> +
> +  - compatible : The following string:
> +        "arcx,anybuss-host"
> +
> +  - reg : bus memory area where the Anybus-S host dpram is located.
> +
> +  - interrupts : interrupt connected to the Anybus-S host interrupt line.
> +	Generic interrupt client node bindings are described in
> +		interrupt-controller/interrupts.txt
> +
> +  - resets : the reset line associated with the Anybus-S host.
> +
> +Optional: use of subnodes
> +-------------------------
> +
> +The card connected to a host may need additional properties. These can be
> +specified in subnodes to the host node.
> +
> +The subnodes are identified by the standard 'reg' property. Which information
> +exactly can be specified depends on the bindings for the function driver
> +for the subnode.
> +
> +Required host node properties when using subnodes:
> +- #address-cells: should be one.
> +- #size-cells: should be zero.
> +
> +Required subnode properties:
> +- reg: Must contain the fieldbus type of the card this subnode describes.
> +
> +Example of usage:
> +-----------------
> +
> +This example places the Anybus-S host on top of the i.MX WEIM parallel bus, see:
> +Documentation/devicetree/bindings/bus/imx-weim.txt
> +
> +&weim {
> +	anybus-host@0 {
> +		compatible = "arcx,anybuss-host";
> +		reg = <0 0x400000 0x800>;
> +		interrupt-parent = <&gpio1>;
> +		interrupts = <1 IRQ_TYPE_LEVEL_LOW>;
> +		resets = <&anybus_bridge 0>;

I'm still not clear what a bridge vs. host is. Both examples are on WEIM 
bus CS0?

> +		/* fsl,weim-cs-timing is a i.MX WEIM bus specific property */
> +		fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
> +				0x00000000 0xa0000240 0x00000000>;
> +		/*
> +		 * optional subnode for a profinet card
> +		 * (fieldbus type = 0x0089)
> +		 */
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		profinet@0 {

Unit-addresses are based on 'reg'. So this should either be '89' or 
based on a definition for the bus (e.g. PCI uses dev and func).

> +			reg = <0x0089>;

Is fieldbus type how one addresses a device on the bus?

> +			/* profinet specific properties go here */
> +		};
> +	};
> +
> +};
> -- 
> 2.17.1
>