I.MX6 MIPI Virtual Chanel 0 Problem

[joachimjaehn]

Hi @ all

I use the IMX.6QDL on an DartMX6 Board from Varicite. I would like to use an MIPI CMOS Gray scale Senor (IMX290). I have running an other Sensor on Virtual Chanel 1. It works without problems. But it is Impossible to change the Virtual Chanel from the IMX290. So i have to use the Virtual Chanel 0. Now i got problems if i change the virtual Chanel of the old Sensor to 0 and the new sensor will not work too. See Attach. If I darken the sensor the image will also darken. So the data comes from the sensor. But I don't get a stable picture.

Both sensors use MIPI with 4Lanes, a data rate of 594Mbps and the data format RAW10. I can't find the differences between VC0 and VC1.

VC0 = > MUX Parallel => IPU0 CSI0 => SMFC => IDMAC => Memory

VC1 => IPU0 CSI1 => SMFC => IDMAC => Memory

I can't find the Problem. can anyone help me?

[Yuri]

Hello,

  useful doc :

https://community.nxp.com/docs/DOC-94312 

Regards,

Yuri.

[Yuri]

Hello,

Perhaps, the following from section 3.2 (MIPI CSI2 Virtual Channel Issue) of i.MX6 IPU TVIN Application Note,

Rev. 0, helps to clarify the issue:

  "For some MIPI CSI2 TVIN chips, when software sets their virtual channel to not 0, they will only
send MIPI long packages (video data) to other virtual channel but keep MIPI short packages (timing data
such as frame start, frame end) on virtual channel 0. Such kind of TVIN chip can’t be supported by iMX6
with not 0 virtual channel. They must work at virtual channel 0.
With such TVIN chip, to hardware design, if parallel CSI0 is also used for another camera sensor,
then the two cameras will fail to work together."

iMX6 IPU TVIN Application Notes 

Regards,

Yuri.

[hbeij]

Hi Joachim,

I'm also starting IMX290 driver development now. Do you care to collaborate with me? Two pair of eyes will see more!

Kind regards,

Hendrik