AML-A311D-CC and cameras

General
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1

Hello,

I’m looking for a platform where I can connect a camera sensor on MIPI CSI but I need to generate a clock in range [6-27]MHz to the 18th pin of the camera connector (CSI_CLKBP). On schematics I found it was connected to the PWMAO_D of the A311D SoC, but I’m unsure about its capabilities. I couldn’t find additional information in the software stack sources.

Is it possible to modify the device tree in order to generate a valid clock for such camera ?

Edit: Figured out that A311D CSI ISP is not currently supported, but I’m not sure it’s a real problem ?

Cheers,
Simon

2

Normaly, we don’t need ISP functionalities but… Can we still grab frames ?

3

In order to get an camera to work, you need the following chain:

  1. Generate proper clocks either via PWM or a clock generator. For many sensors, this is unnecessary.
  2. MIPI CSI support (this is not yet available on upstream kernel). This is probably your blocker.
  3. ISP if the sensor does not provide YUV output.
4

Hello @librecomputer, thanks for your answer.

  1. Well for this sensor it could be needed but not mandatory I could use an external oscillator too.
  2. If not on upstream, is there an implementation on your side or on Khadas side ?
  3. He does not provide YUV but we fake it using Y8_1X8 (GREY).

Cheers, Simon

5

If you search for amlcam, there’s code for driving the CSI with various YUV sensors. It’s in the NDA Yocto SDK: aml-comp/hardware/aml-5.4/amlogic/arm-isp/driver/linux/kernel/mipi_yuv_sensor/amlcam

Perhaps you can find it on GitHub but it will require porting to upstream. We plan to bring CSI up around the end of the year. Khadas doesn’t care about upstream.

6

Pretty cool, I will keep an eye on this :eyes: