Re: [PATCH v2 1/3] dt-bindings: interconnect: Add Qualcomm CAMNOC ICC binding
From: Krzysztof Kozlowski
Date: Thu Aug 27 2026 - 05:30:09 EST
On 27/08/2026 11:23, Krzysztof Kozlowski wrote:
> On Wed, Aug 19, 2026 at 12:32:09PM +0300, Atanas Filipov wrote:
>> Add binding for the Qualcomm CAMNOC interconnect provider. CAMNOC is
>> the internal AXI interconnect within the camera subsystem. Multiple
>> sub-devices share CAM_CC_CAMNOC_AXI_CLK; the ICC provider aggregates
>> their bandwidth votes and scales the clock accordingly, avoiding the
>> last-writer-wins race from direct clk_set_rate() calls.
>>
>> Signed-off-by: Atanas Filipov <atanas.filipov@xxxxxxxxxxxxxxxx>
>> ---
>> .../bindings/interconnect/qcom,camnoc.yaml | 124 ++++++++++++++++++
>> .../dt-bindings/interconnect/qcom,camnoc.h | 52 ++++++++
>> 2 files changed, 176 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..b2659db2cf27
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/interconnect/qcom,camnoc.yaml
>
> Filename must match compatible.
>
>> @@ -0,0 +1,124 @@
>> +# 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:
>> + - Atanas Filipov <atanas.filipov@xxxxxxxxxxxxxxxx>
>> +
>> +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, IPE, etc.) and the external
>> + memory interconnect. Multiple consumers may independently request
>> + bandwidth via icc_set_bw(); the CAMNOC ICC provider aggregates all active
>> + votes and scales CAM_CC_CAMNOC_AXI_CLK accordingly, avoiding the
>> + last-writer-wins race that arises when each consumer calls clk_set_rate()
>> + directly on the shared clock.
>> +
>> + Each camera sub-device driver that shares the CAMNOC AXI clock should
>> + obtain an ICC path from its master port to SLAVE_CAMNOC_AXI and vote for
>> + bandwidth using the port IDs defined in
>> + include/dt-bindings/interconnect/qcom,camnoc.h.
>> +
>> +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 provider node */
>
> Drop, redundant.
>
>> + cam_virt: interconnect-cam-virt {
>
> Drop unused label
>
>> + compatible = "qcom,sm8250-cam-virt";
>> + clocks = <&camcc CAM_CC_CAMNOC_AXI_CLK>;
>> + clock-names = "camnoc_axi";
>> + #interconnect-cells = <1>;
>> + };
>> +
>> + /*
>> + * Simple consumer example: IFE sub-device voting for CAMNOC bandwidth
>
>
> And what are the writing schema/bindings asking about consumers? Or
> DTS101 slides? Look at other bindings instead of coming with own style.
>
And:
Drop second/last, redundant "binding". The "dt-bindings" prefix is
already stating that these are bindings.
See also:
https://elixir.bootlin.com/linux/v7.1-rc7/source/Documentation/devicetree/bindings/submitting-patches.rst#L23
Best regards,
Krzysztof