Re: [PATCH v7 3/7] dt-bindings: bus: add CDX bus controller for versal net

[Rob Herring <robh@kernel.org>]

On Tue, Jan 31, 2023 at 02:10:45PM +0530, Nipun Gupta wrote:
> Add CDX bus controller device tree bindings for versal-net
> devices.
> 
> Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
> ---
>  .../bindings/bus/xlnx,versal-net-cdx.yaml     | 68 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 69 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/bus/xlnx,versal-net-cdx.yaml
> 
> diff --git a/Documentation/devicetree/bindings/bus/xlnx,versal-net-cdx.yaml b/Documentation/devicetree/bindings/bus/xlnx,versal-net-cdx.yaml
> new file mode 100644
> index 000000000000..8452185b9d70
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/xlnx,versal-net-cdx.yaml
> @@ -0,0 +1,68 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/bus/xlnx,versal-net-cdx.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: AMD CDX bus controller
> +
> +description: |
> +  CDX bus controller for AMD devices is implemented to dynamically
> +  detect CDX bus and devices on these bus using the firmware.
> +  The CDX bus manages multiple FPGA based hardware devices, which
> +  can support network, crypto or any other specialized type of
> +  devices. These FPGA based devices can be added/modified dynamically
> +  on run-time.
> +
> +  All devices on the CDX bus will have a unique streamid (for IOMMU)
> +  and a unique device ID (for MSI) corresponding to a requestor ID
> +  (one to one associated with the device). The streamid and deviceid
> +  are used to configure SMMU and GIC-ITS respectively.
> +
> +  iommu-map property is used to define the set of stream ids
> +  corresponding to each device and the associated IOMMU.
> +
> +  The MSI writes are accompanied by sideband data (Device ID).
> +  The msi-map property is used to associate the devices with the
> +  device ID as well as the associated ITS controller.
> +
> +  rproc property (xlnx,rproc) is used to identify the remote processor
> +  with which APU (Application Processor Unit) interacts to find out
> +  the bus and device configuration.
> +
> +maintainers:
> +  - Nipun Gupta <nipun.gupta@amd.com>
> +  - Nikhil Agarwal <nikhil.agarwal@amd.com>
> +
> +properties:
> +  compatible:
> +    const: xlnx,versal-net-cdx
> +
> +  iommu-map: true
> +
> +  msi-map: true
> +
> +  xlnx,rproc:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      phandle to the remoteproc_r5 rproc node using which APU interacts
> +      with remote processor.
> +
> +required:
> +  - compatible
> +  - iommu-map
> +  - msi-map
> +  - xlnx,rproc
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    cdx {
> +        compatible = "xlnx,versal-net-cdx";
> +        /* define map for RIDs 250-259 */
> +        iommu-map = <250 &smmu 250 10>;
> +        /* define msi map for RIDs 250-259 */
> +        msi-map = <250 &its 250 10>;
> +        xlnx,rproc = <&remoteproc_r5>;

There's no addresses associated with this bus? Like the address range 
the devices are at. You should have 'ranges' whether Linux needs it yet 
or not.

Rob