Re: [PATCH v1 1/3] dt-bindings: interconnect: Add Qualcomm CAMNOC ICC binding

[Dmitry Baryshkov]

On Fri, Aug 07, 2026 at 02:49:49PM +0300, Atanas Filipov wrote:
> Add a device tree binding for the Qualcomm Camera Network-on-Chip
> (CAMNOC) interconnect provider. CAMNOC is the internal AXI
> interconnect within the camera subsystem that arbitrates bandwidth
> between camera sub-devices and the external memory interconnect.
> 
> The CAMNOC ICC provider aggregates bandwidth requests from multiple
> independent consumers and scales the CAMNOC AXI clock accordingly,
> avoiding the race conditions that arise when each consumer calls
> clk_set_rate() directly on the shared clock.
> 
> Signed-off-by: Atanas Filipov <atanas.filipov@xxxxxxxxxxxxxxxx>
> ---
>  .../bindings/interconnect/qcom,camnoc.yaml    | 98 +++++++++++++++++++
>  .../dt-bindings/interconnect/qcom,camnoc.h    | 12 +++
>  2 files changed, 110 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml
>  create mode 100644 include/dt-bindings/interconnect/qcom,camnoc.h
> 
> diff --git a/Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml b/Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml
> new file mode 100644
> index 000000000000..b2f5c140ff80
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml
> @@ -0,0 +1,98 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/interconnect/qcom,camnoc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm Camera NOC (CAMNOC) Interconnect Provider
> +
> +maintainers:
> +  - Aleksandar Filipov <quic_afilipov@xxxxxxxxxxx>
> +
> +description:
> +  The Camera Network-on-Chip (CAMNOC) is the internal AXI interconnect
> +  within the Qualcomm camera subsystem. It arbitrates AXI bandwidth
> +  between camera sub-devices (IFE, JPEG, BPS, etc.) and the external
> +  memory interconnect. Multiple consumers may independently request
> +  bandwidth; the CAMNOC ICC provider aggregates these requests and
> +  scales CAM_CC_CAMNOC_AXI_CLK accordingly.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - qcom,sm8250-cam-virt
> +
> +  clocks:
> +    items:
> +      - description: CAMNOC AXI clock
> +
> +  clock-names:
> +    items:
> +      - const: camnoc_axi
> +
> +  '#interconnect-cells':
> +    const: 1
> +
> +required:
> +  - compatible
> +  - clocks
> +  - clock-names
> +  - '#interconnect-cells'
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/qcom,camcc-sm8250.h>
> +    #include <dt-bindings/interconnect/qcom,camnoc.h>
> +
> +    camnoc_icc: interconnect {
> +        compatible = "qcom,sm8250-cam-virt";
> +        clocks = <&camcc CAM_CC_CAMNOC_AXI_CLK>;
> +        clock-names = "camnoc_axi";
> +        #interconnect-cells = <1>;
> +    };
> +
> +    /* Example camera sub-device consuming the CAMNOC provider above */
> +    camera-subsystem@ac53000 {
> +        reg = <0x0ac53000 0x1000>;
> +
> +        interconnects = <&camnoc_icc MASTER_CAMNOC_JPEG
> +                         &camnoc_icc SLAVE_CAMNOC_AXI>;
> +        interconnect-names = "camnoc";
> +
> +        /*
> +         * Optional: an operating-points-v2 table lets the consumer
> +         * drive its CAMNOC bandwidth vote from the same OPP that
> +         * selects its core clock rate and RPMh performance state.

Is this a table for the camera-subsystem or for the CAMNOC_AXI_CLK? In
the latter case, the OPP table should be a part of the camnoc device.

> +         */
> +        operating-points-v2 = <&camera_opp_table>;
> +
> +        camera_opp_table: opp-table {
> +            compatible = "operating-points-v2";
> +
> +            opp-100000000 {
> +                opp-hz = /bits/ 64 <100000000>;
> +                opp-peak-kBps = <22246>;
> +                required-opps = <&rpmhpd_opp_min_svs>;
> +            };
> +
> +            opp-200000000 {
> +                opp-hz = /bits/ 64 <200000000>;
> +                opp-peak-kBps = <44492>;
> +                required-opps = <&rpmhpd_opp_low_svs>;
> +            };
> +
> +            opp-400000000 {
> +                opp-hz = /bits/ 64 <400000000>;
> +                opp-peak-kBps = <88983>;
> +                required-opps = <&rpmhpd_opp_svs>;
> +            };
> +
> +            opp-480000000 {
> +                opp-hz = /bits/ 64 <480000000>;
> +                opp-peak-kBps = <106780>;
> +                required-opps = <&rpmhpd_opp_svs_l1>;
> +            };
> +        };
> +    };
> diff --git a/include/dt-bindings/interconnect/qcom,camnoc.h b/include/dt-bindings/interconnect/qcom,camnoc.h
> new file mode 100644
> index 000000000000..a03f5e3f6446
> --- /dev/null
> +++ b/include/dt-bindings/interconnect/qcom,camnoc.h
> @@ -0,0 +1,12 @@
> +/* SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause */
> +/*
> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
> + */
> +
> +#ifndef __DT_BINDINGS_INTERCONNECT_QCOM_CAMNOC_H
> +#define __DT_BINDINGS_INTERCONNECT_QCOM_CAMNOC_H
> +
> +#define MASTER_CAMNOC_JPEG	0

I guess, there are other connection ports. Please describe them.

> +#define SLAVE_CAMNOC_AXI	1
> +
> +#endif /* __DT_BINDINGS_INTERCONNECT_QCOM_CAMNOC_H */
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry