Re: [RFC 1/2] dt-bindings: firmware: arm,scmi: Add support for memlat vendor protocol

[Rob Herring]

On Thu, Nov 03, 2022 at 10:28:31AM +0530, Sibi Sankar wrote:
> Add bindings support for the SCMI QTI memlat (memory latency) vendor
> protocol. The memlat vendor protocol enables the frequency scaling of
> various buses (L3/LLCC/DDR) based on the memory latency governor
> running on the CPUSS Control Processor.

I thought the interconnect binding was what provided details for bus 
scaling.

> 
> Signed-off-by: Sibi Sankar <quic_sibis@xxxxxxxxxxx>
> ---
>  .../devicetree/bindings/firmware/arm,scmi.yaml     | 164 +++++++++++++++++++++
>  1 file changed, 164 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> index 1c0388da6721..efc8a5a8bffe 100644
> --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
> @@ -189,6 +189,47 @@ properties:
>        reg:
>          const: 0x18
>  
> +  protocol@80:
> +    type: object
> +    properties:
> +      reg:
> +        const: 0x80
> +
> +      qcom,bus-type:
> +        $ref: /schemas/types.yaml#/definitions/uint32-array
> +        items:
> +          minItems: 1
> +        description:
> +          Identifier of the bus type to be scaled by the memlat protocol.
> +
> +      cpu-map:

cpu-map only goes under /cpus node.

> +        type: object
> +        description:
> +          The list of all cpu cluster configurations to be tracked by the memlat protocol
> +
> +        patternProperties:
> +          '^cluster[0-9]':
> +            type: object
> +            description:
> +              Each cluster node describes the frequency domain associated with the
> +              CPUFREQ HW engine and bandwidth requirements of the buses to be scaled.
> +
> +            properties:

cpu-map nodes don't have properties.

> +              operating-points-v2: true
> +
> +              qcom,freq-domain:

Please don't add new users of this. Use the performance-domains binding 
instead.

> +                $ref: /schemas/types.yaml#/definitions/phandle-array
> +                description:
> +                  Reference to the frequency domain of the CPUFREQ HW engine
> +                items:
> +                  - items:
> +                      - description: phandle to CPUFREQ HW engine
> +                      - description: frequency domain associated with the cluster
> +
> +            required:
> +              - qcom,freq-domain
> +              - operating-points-v2
> +
>  additionalProperties: false
>  
>  patternProperties:
> @@ -429,4 +470,127 @@ examples:
>          };
>      };
>  
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +    firmware {
> +        scmi {
> +            compatible = "arm,scmi";
> +
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            mboxes = <&cpucp_mbox>;
> +            mbox-names = "tx";
> +            shmem = <&cpu_scp_lpri>;
> +
> +            scmi_memlat: protocol@80 {
> +                reg = <0x80>;
> +                qcom,bus-type = <0x2>;
> +
> +                cpu-map {
> +                    cluster0 {
> +                        qcom,freq-domain = <&cpufreq_hw 0>;
> +                        operating-points-v2 = <&cpu0_opp_table>;
> +                    };
> +
> +                    cluster1 {
> +                        qcom,freq-domain = <&cpufreq_hw 1>;
> +                        operating-points-v2 = <&cpu4_opp_table>;
> +                    };
> +
> +                    cluster2 {
> +                        qcom,freq-domain = <&cpufreq_hw 2>;
> +                        operating-points-v2 = <&cpu7_opp_table>;
> +                    };
> +                };
> +            };
> +        };
> +
> +        cpu0_opp_table: opp-table-cpu0 {
> +            compatible = "operating-points-v2";
> +
> +            cpu0_opp_300mhz: opp-300000000 {
> +                opp-hz = /bits/ 64 <300000000>;
> +                opp-peak-kBps = <9600000>;
> +            };
> +
> +            cpu0_opp_1325mhz: opp-1324800000 {
> +                opp-hz = /bits/ 64 <1324800000>;
> +                opp-peak-kBps = <33792000>;
> +            };
> +
> +            cpu0_opp_2016mhz: opp-2016000000 {
> +                opp-hz = /bits/ 64 <2016000000>;
> +                opp-peak-kBps = <48537600>;
> +            };
> +        };
> +
> +        cpu4_opp_table: opp-table-cpu4 {
> +            compatible = "operating-points-v2";
> +
> +            cpu4_opp_691mhz: opp-691200000 {
> +                opp-hz = /bits/ 64 <691200000>;
> +                opp-peak-kBps = <9600000>;
> +            };
> +
> +            cpu4_opp_941mhz: opp-940800000 {
> +                opp-hz = /bits/ 64 <940800000>;
> +                opp-peak-kBps = <17817600>;
> +            };
> +
> +            cpu4_opp_2611mhz: opp-2611200000 {
> +                opp-hz = /bits/ 64 <2611200000>;
> +                opp-peak-kBps = <48537600>;
> +            };
> +        };
> +
> +        cpu7_opp_table: opp-table-cpu7 {
> +            compatible = "operating-points-v2";
> +
> +            cpu7_opp_806mhz: opp-806400000 {
> +                opp-hz = /bits/ 64 <806400000>;
> +                opp-peak-kBps = <9600000>;
> +            };
> +
> +            cpu7_opp_2381mhz: opp-2380800000 {
> +                opp-hz = /bits/ 64 <2380800000>;
> +                opp-peak-kBps = <44851200>;
> +            };
> +
> +            cpu7_opp_2515mhz: opp-2515200000 {
> +                opp-hz = /bits/ 64 <2515200000>;
> +                opp-peak-kBps = <48537600>;
> +            };
> +        };
> +    };
> +
> +
> +    soc {
> +        #address-cells = <2>;
> +        #size-cells = <2>;
> +
> +        cpucp_mbox: mailbox@17400000 {
> +            compatible = "qcom,cpucp-mbox";
> +            reg =   <0x0 0x17c00000 0x0 0x10>, <0x0 0x18590300 0x0 0x700>;
> +            interrupts = <GIC_SPI 62 IRQ_TYPE_LEVEL_HIGH>;
> +            #mbox-cells = <0>;
> +        };
> +
> +        sram@18509400 {
> +            compatible = "mmio-sram";
> +            reg = <0x0 0x18509400 0x0 0x400>;
> +            no-memory-wc;
> +
> +            #address-cells = <1>;
> +            #size-cells = <1>;
> +            ranges = <0x0 0x0 0x18509400 0x400>;
> +
> +            cpu_scp_lpri: scp-sram-section@0 {
> +                compatible = "arm,scmi-shmem";
> +                reg = <0x0 0x80>;
> +            };
> +        };
> +    };
> +
>  ...
> -- 
> 2.7.4
> 
>