Re: [PATCH v2 10/14] dt-bindings: media: qcom: Add CAMSS Offline Processing Engine (OPE)

Konrad Dybcio
2026-04-28T10:16:02Z

On 4/27/26 10:33 PM, Loic Poulain wrote:
> On Mon, Apr 27, 2026 at 4:22 PM Konrad Dybcio
> <konrad.dybcio@oss.qualcomm.com> wrote:
>>
>> On 4/27/26 2:43 PM, Loic Poulain wrote:
>>> Add Devicetree binding documentation for the Qualcomm Camera Subsystem
>>> Offline Processing Engine (OPE) found on platforms such as Agatti.
>>> The OPE is a memory-to-memory image processing block which operates
>>> on frames read from and written back to system memory.
>>>
>>> Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
>>> ---
>>
>> [...]
>>
>>> + clocks = <&gcc GCC_CAMSS_OPE_CLK>,
>>> + <&gcc GCC_CAMSS_OPE_AHB_CLK>,
>>> + <&gcc GCC_CAMSS_NRT_AXI_CLK>;
>>
>> Should the two AXI clocks be aggregated by camss-top instead?
>>
>> Otherwise we run the risk of the OPE driver setting a rate of A
>> and another sub-device setting a rate of B
>
> On qcm2290, OPE appears to be the only consumer of the NRT AXI clock,
> while the capture path (VFE/TFE) relies on the RT AXI clock. That
> said, this may not always be the case and these clocks (AXI / NRT‑AXI
> / RT‑AXI) seem like they could reasonably be managed at the
> camss-bus/top level.
>
> The open question is how the NRT AXI clock should be enabled when
> required? enabling them unconditionally (similar to other camss PM
> clocks), introducing a dedicated CAMSS top‑level interface for voting,
> or leveraging an existing framework to handle this?

So, interconnect, or some internal, smaller version of it?

Konrad