Re: [PATCH v4 1/4] dt-bindings: interconnect: qcom,sdm845-cpu-bwmon: add BWMON device

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Wed 01 Jun 03:11 PDT 2022, Krzysztof Kozlowski wrote:

> Add bindings for the Qualcomm Bandwidth Monitor device providing
> performance data on interconnects.  The bindings describe only BWMON
> version 4, e.g. the instance on SDM845 between CPU and Last Level Cache
> Controller.
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Acked-by: Georgi Djakov <djakov@kernel.org>
> ---
>  .../interconnect/qcom,sdm845-cpu-bwmon.yaml   | 97 +++++++++++++++++++
>  1 file changed, 97 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interconnect/qcom,sdm845-cpu-bwmon.yaml
> 
> diff --git a/Documentation/devicetree/bindings/interconnect/qcom,sdm845-cpu-bwmon.yaml b/Documentation/devicetree/bindings/interconnect/qcom,sdm845-cpu-bwmon.yaml
> new file mode 100644
> index 000000000000..8c82e06ee432
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interconnect/qcom,sdm845-cpu-bwmon.yaml
> @@ -0,0 +1,97 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/interconnect/qcom,sdm845-cpu-bwmon.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm Interconnect Bandwidth Monitor
> +
> +maintainers:
> +  - Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> +
> +description:
> +  Bandwidth Monitor measures current throughput on buses between various NoC
> +  fabrics and provides information when it crosses configured thresholds.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - qcom,sdm845-cpu-bwmon       # BWMON v4

It seems the thing that's called bwmon v4 is compatible with a number of
different platforms, should we add a generic compatible to the binding
as well, to avoid having to update the implementation for each SoC?

(I.e. "qcom,sdm845-cpu-bwmon", "qcom,bwmon-v4")

Regards,
Bjorn

> +
> +  interconnects:
> +    maxItems: 2
> +
> +  interconnect-names:
> +    items:
> +      - const: ddr
> +      - const: l3c
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  operating-points-v2: true
> +  opp-table: true
> +
> +  reg:
> +    # Currently described BWMON v4 and v5 use one register address space.
> +    # BWMON v2 uses two register spaces - not yet described.
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - interconnects
> +  - interconnect-names
> +  - interrupts
> +  - operating-points-v2
> +  - opp-table
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interconnect/qcom,osm-l3.h>
> +    #include <dt-bindings/interconnect/qcom,sdm845.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +    pmu@1436400 {
> +        compatible = "qcom,sdm845-cpu-bwmon";
> +        reg = <0x01436400 0x600>;
> +
> +        interrupts = <GIC_SPI 581 IRQ_TYPE_LEVEL_HIGH>;
> +
> +        interconnects = <&gladiator_noc MASTER_APPSS_PROC 3 &mem_noc SLAVE_EBI1 3>,
> +                        <&osm_l3 MASTER_OSM_L3_APPS &osm_l3 SLAVE_OSM_L3>;
> +        interconnect-names = "ddr", "l3c";
> +
> +        operating-points-v2 = <&cpu_bwmon_opp_table>;
> +
> +        cpu_bwmon_opp_table: opp-table {
> +            compatible = "operating-points-v2";
> +
> +            opp-0 {
> +                opp-peak-kBps = <800000 4800000>;
> +            };
> +            opp-1 {
> +                opp-peak-kBps = <1804000 9216000>;
> +            };
> +            opp-2 {
> +                opp-peak-kBps = <2188000 11980800>;
> +            };
> +            opp-3 {
> +                opp-peak-kBps = <3072000 15052800>;
> +            };
> +            opp-4 {
> +                opp-peak-kBps = <4068000 19353600>;
> +            };
> +            opp-5 {
> +                opp-peak-kBps = <5412000 20889600>;
> +            };
> +            opp-6 {
> +                opp-peak-kBps = <6220000 22425600>;
> +            };
> +            opp-7 {
> +                opp-peak-kBps = <7216000 25497600>;
> +            };
> +        };
> +    };
> -- 
> 2.34.1
>