Quoting David Dai (2019-07-19 13:32:23)
> Redefine the Network-on-Chip devices to more accurately describe
> the interconnect topology on Qualcomm's SDM845 platform. Each
> interconnect device can communicate with different instances of the
> RPMh hardware which are described as RSCs(Resource State Coordinators).
>
> Signed-off-by: David Dai <daidavid1@xxxxxxxxxxxxxx>
> ---
> diff --git a/Documentation/devicetree/bindings/interconnect/qcom,bcm-voter.txt b/Documentation/devicetree/bindings/interconnect/qcom,bcm-voter.txt
> new file mode 100644
> index 0000000..2cf7da2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interconnect/qcom,bcm-voter.txt
> @@ -0,0 +1,32 @@
> +Qualcomm BCM-Voter interconnect driver binding
> +-----------------------------------------------------------
> +
> +The Bus Clock Manager (BCM) is a dedicated hardware accelerator
> +that manages shared system resources by aggregating requests
> +from multiple Resource State Coordinators (RSC). Interconnect
> +providers are able to vote for aggregated thresholds values from
> +consumers by communicating through their respective RSCs.
> +
> +Required properties :
> +- compatible : shall contain only one of the following:
> + "qcom,sdm845-bcm-voter",
> +
> +Examples:
> +
> +apps_rsc: rsc@179c0000 {
But there isn't a reg property.
> + label = "apps_rsc";
Is label required?
> + compatible = "qcom,rpmh-rsc";
> +
> + apps_bcm_voter: bcm_voter {
> + compatible = "qcom,sdm845-bcm-voter";
> + };
> +}
> +
> +disp_rsc: rsc@179d0000 {
> + label = "disp_rsc";
> + compatible = "qcom,rpmh-rsc";
> +
> + disp_bcm_voter: bcm_voter {
> + compatible = "qcom,sdm845-bcm-voter";
> + };
> +}
> diff --git a/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt b/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
> index 5c4f1d9..27f9ed9 100644
> --- a/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
> +++ b/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
> @@ -4,21 +4,43 @@ Qualcomm SDM845 Network-On-Chip interconnect driver binding
> SDM845 interconnect providers support system bandwidth requirements through
> RPMh hardware accelerators known as Bus Clock Manager (BCM). The provider is
> able to communicate with the BCM through the Resource State Coordinator (RSC)
> -associated with each execution environment. Provider nodes must reside within
> -an RPMh device node pertaining to their RSC and each provider maps to a single
> -RPMh resource.
> +associated with each execution environment. Provider nodes must point to at
> +least one RPMh device child node pertaining to their RSC and each provider
> +can map to multiple RPMh resources.
>
> Required properties :
> - compatible : shall contain only one of the following:
> - "qcom,sdm845-rsc-hlos"
> + "qcom,sdm845-aggre1_noc",
> + "qcom,sdm845-aggre2_noc",
> + "qcom,sdm845-config_noc",
> + "qcom,sdm845-dc_noc",
> + "qcom,sdm845-gladiator_noc",
> + "qcom,sdm845-mem_noc",
> + "qcom,sdm845-mmss_noc",
> + "qcom,sdm845-system_noc",
> - #interconnect-cells : should contain 1
> +- reg : shall contain base register location and length
> +- qcom,bcm-voter : shall contain phandles to bcm voters
>
> Examples:
>
> -apps_rsc: rsc {
> - rsc_hlos: interconnect {
> - compatible = "qcom,sdm845-rsc-hlos";
> - #interconnect-cells = <1>;
> - };
> +aggre1_noc: interconnect@16e0000 {
> + compatible = "qcom,sdm845-aggre1_noc";
> + reg = <0x16e0000 0xd080>;
> + interconnect-cells = <1>;
> + qcom,bcm-voter = <&apps_bcm_voter>;
> };
>
> +mmss_noc: interconnect@1740000 {
> + compatible = "qcom,sdm845-mmss_noc";
> + reg = <0x1740000 0x1c1000>;
> + interconnect-cells = <1>;
> + qcom,bcm-voter = <&apps_bcm_voter>, <&disp_bcm_voter>;
> +};
> +
> +mem_noc: interconnect@1380000 {
> + compatible = "qcom,sdm845-mem_noc";
> + reg = <0 0x1380000 0 0x27200>;
> + #interconnect-cells = <1>;
> + qcom,bcm-voter = <&apps_bcm_voter>, <&disp_bcm_voter>;
> +};
How does a consumer target a particular RSC? For example, how can
display decide to use the disp_bcm_voter node from mem_noc here? Maybe
you can add that consumer to the example?
