Re: [PATCH v9 2/8] dt-bindings: Introduce interconnect binding

Rob Herring
2018-09-25T18:02:15Z

On Fri, Aug 31, 2018 at 05:01:45PM +0300, Georgi Djakov wrote:
> This binding is intended to represent the relations between the interconnect
> controllers (providers) and consumer device nodes. It will allow creating links
> between consumers and interconnect paths (exposed by interconnect providers).

As I mentioned in person, I want to see other SoC families using this
before accepting. They don't have to be ready for upstream, but WIP
patches or even just a "yes, this works for us and we're going to use
this binding on X".

Also, I think the QCom GPU use of this should be fully sorted out. Or
more generically how this fits into OPP binding which seems to be never
ending extended...

> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
> ---
> .../bindings/interconnect/interconnect.txt | 60 +++++++++++++++++++
> 1 file changed, 60 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/interconnect/interconnect.txt
>
> diff --git a/Documentation/devicetree/bindings/interconnect/interconnect.txt b/Documentation/devicetree/bindings/interconnect/interconnect.txt
> new file mode 100644
> index 000000000000..5cb7d3c8d44d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interconnect/interconnect.txt
> @@ -0,0 +1,60 @@
> +Interconnect Provider Device Tree Bindings
> +=========================================
> +
> +The purpose of this document is to define a common set of generic interconnect
> +providers/consumers properties.
> +
> +
> += interconnect providers =
> +
> +The interconnect provider binding is intended to represent the interconnect
> +controllers in the system. Each provider registers a set of interconnect
> +nodes, which expose the interconnect related capabilities of the interconnect
> +to consumer drivers. These capabilities can be throughput, latency, priority
> +etc. The consumer drivers set constraints on interconnect path (or endpoints)
> +depending on the use case. Interconnect providers can also be interconnect
> +consumers, such as in the case where two network-on-chip fabrics interface
> +directly

missing '.'

> +
> +Required properties:
> +- compatible : contains the interconnect provider compatible string
> +- #interconnect-cells : number of cells in a interconnect specifier needed to
> + encode the interconnect node id
> +
> +Example:
> +
> + snoc: snoc@580000 {
> + compatible = "qcom,msm8916-snoc";
> + #interconnect-cells = <1>;
> + reg = <0x580000 0x14000>;
> + clock-names = "bus_clk", "bus_a_clk";
> + clocks = <&rpmcc RPM_SMD_SNOC_CLK>,
> + <&rpmcc RPM_SMD_SNOC_A_CLK>;
> + };
> +
> +
> += interconnect consumers =
> +
> +The interconnect consumers are device nodes which dynamically express their
> +bandwidth requirements along interconnect paths they are connected to. There
> +can be multiple interconnect providers on a SoC and the consumer may consume
> +multiple paths from different providers depending on use case and the
> +components it has to interact with.
> +
> +Required properties:
> +interconnects : Pairs of phandles and interconnect provider specifier to denote
> + the edge source and destination ports of the interconnect path.
> +
> +Optional properties:
> +interconnect-names : List of interconnect path name strings sorted in the same
> + order as the interconnects property. Consumers drivers will use
> + interconnect-names to match interconnect paths with interconnect
> + specifiers.

specifier pairs.

> +
> +Example:
> +
> + sdhci@7864000 {
> + ...
> + interconnects = <&pnoc MASTER_SDCC_1 &bimc SLAVE_EBI_CH0>;
> + interconnect-names = "ddr";
> + };