On 07/06/2023 14:58, Dmitry Baryshkov wrote:

On 06/06/2023 21:03, Steve Sandven wrote:

...

Hi Dmitry  -

Just wanted to follow up on investigation of virtual channel support on our 4000-OEM product (snapdragon 820C) – would appreciate any information or ideas you can provide.

Do you guys have any experience with supporting multiple cameras over a single mipi channel?

Last week we started the research, but unfortunately our main camss expert was OOO.

Bryan, can you hopefully comment regarding CSI Virtual channel support on MSM8996?

So at the moment upstream we have support for virtual channel data on sm8250 which is pixel data + meta data i.e. the sensor used provides pixel data and some kind of additional temperature data.

On another platform - I have a sensor setup where a RGB and B+W sensor are connected to the same MIPI interface.

We would have to figure out two sensors as opposed to sensor + meta data on the VC in CAMSS.

That said in principle that's doable.

On 8996 should be able to support multiple stream pixel data to the same CSIPHY.

I will hunt to find some more detail within qualcomm's documentation but as I say in principle at a high level its CAMSS rather than 8096/8996 specific work, though there may be some support in the silicon we can exploit to make it easier.

--- bod

On 09/06/2023 00:54, Steve Sandven wrote:

Hi Bryan -

Thanks for your response, we are certainly interested in mipi virtual channels as reducing cabling for our customers is a big deal.

Typically, we will see a gimbal with 3 or 4 cameras, and only 2 will be actively captured and processed/displayed by our system at a time - then switching to a different combination of 2 cameras.

None of these cameras will be the same resolution, or frame rate, and certainly not frame synchronized.

We currently have 1 mipi camera that has a metadata stream and B/W. The " RGB and B+W" sounds like a Boson MIPI which is coming out soon and we are interested in as well.

Look forward to hearing what you find out.

Best regards, Steve

Steve Sandven | Principal Software Engineer | SightLine Applications Inc. | Onboard Video Processing | he/him 503 880-6195 (mobile) | www.sightlineapplications.com

Hi.

I did some follow up on this. I believe 8x96 has three RDI - raw data interface lines per IFE - image front end.

So that means yes the hardware can support virtual channels, each RDI line is a channel.

We need to replicate similar functionality as was added in 8250 for 8x96.

* 89013969e2324 - media: camss: sm8250: Pipeline starting and stopping for multiple virtual channels (9 weeks ago) * 1c4abf0246d2a - media: camss: vfe-480: Multiple outputs support for SM8250 (9 weeks ago) * 8ce158c1be981 - media: camss: vfe: Reserve VFE lines on stream start and link to CSID (9 weeks ago) * 3c4ed72a16bc6 - media: camss: sm8250: Virtual channels for CSID (9 weeks ago)

Less work for 8x96 though since the core CAMSS driver has been updated already to handle the VCs - multi-stream in Linux parlance.

--- bod