Xavier NX and TC358840 HDMI to MIPI-CSI Bridge

Hi All,

I can’t seem to find out anywhere if 4kp30 and / or 4kp60 is supported using a TC358840 bridge chip and the Xavier NX. The NX can now support encoding at 4kp60 but I only see references to this frame size and rate but nothing to suggest it will definitely work or not. If not, then is there a nVidia board that can support this will the same or better CUDA core count and tensorflow cores please?

Thanks and all comments are appreciated,

Dan

I this you can check TX2 base Jetson device like TX2/TX2 NX/TX2 4G

Hi Shane et al,

So I guess if my NX is based on the TX2 (tegra194) then it should all work? One other question; I can see that the CSI port has i2c connected to pins 215 and 213 but when I perform a modprobe there’s no activity on the bus, is there another port that I should be using or is this a fault with my carrier or its configuration as imx219 drivers are trying to load on boot?

(The carrier is the Auvidea JNX30-PD and I’ve had no help from Auvidea at all, in fact it seems they’ve vanished from the face of the earth! It’s the only carrier I can find with the full 4 lanes on AB and CD CSI ports).

Any help from anyone regarding this would be greatly appreciated and in the mean time I’ll probe the other i2c buses to see if there’s anything going on there.

Kind Regards,

Dan

TX2 base is t186 instead of t194.

So a couple of things, my INT line wasn’t strapped to set the address of the chip which is now set and I can do an “i2cdetect -y -r 9” and I get a device at 0x0F which is the TC358840 chip, it then halts printing anything further out on the screen from the above command at 0x48 and 0x49 before carrying on which is strange but does recover ok after a few seconds.

Now the next issue is no device appearing as I thought it should do. I expected a /dev/video0 device but nothing. In fact after a reboot but before issuing the modprobe command there is no difference to what I get after the modprobe command. The driver is listed when I run “lsmod” and it has 0 for the used by column which to me means that it’s not connected up internally to anything or there is some other error.

What is going on, please can someone shed some light on this problem, pretty please???

Kind Regards, Dan

You may need to print some debug message in the _probe() function to get more information to know it root cause.

Hi Shane, I’ll look at that and see what happens and post the results. Is there anyone on here that has had some experience with this chip and the Xavier NX platform??

Cheers, Dan

What’s the bus-width in your device tree?

Hi Shane,

I’m quite new to all this devicetree stuff so I don’t know where to look I’m afraid but if you point me in the right direction I can take a look and get back to you. At the moment I’m following the JetsonHacks github repo on compiling the Kernel as I think there’s some sort of mismatch going on, the reason I say this is that initrd.img is linked to initrd.img-4.9.140-tegra and my kernel should be 4.9.253. So I thought it best to recompile and install the kernel with the imx219 camera removed and make sure the tc358840 drivers are selected. Once that’s done I’ll check it again.

I would like to follow your train of thought though as it’ll be better than mine lol!

Cheers, Dan

Please have further debug and checking if apply correct device tree for this device.

Hi Shane,

I’ve seen that this chip uses 8 CSI lanes for 4kp30 input so it won’t work with the NX, I did see however that others are using the LT6911UXC and I have some of these as engineering samples and would like to get them up and running. I see the kernel drivers are there for this part and I also saw a link that might help me, however it doesn’t seem to work anymore: https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/camera_sensor_prog.html#wwpID0E0XF0HA

Do you have an update link to this please? Or any other pointers in getting the drivers up and running so I can test it with the “yavta” application please?

Kind Regards, Dan

Xavier NX don’t support 8 lane configure. So you may try 4 lane 1080p@60

Hi Shane,

Does this mean that the Xavier NX does not support any MIPI-CSI input at 4k resolutions then? I was under the impression that it did but now I’m starting to wonder if this is possible in any way shape or form, do any of the nVidia boards support 4kp60 or 4kp30 on the MIPI-CSI bus?? I ask this because our end product depends on this resolution for medical imaging and hence is at the forefront of our requirements!! I seriously hope one does as otherwise we’d have to drop the nVidia products altogether and find another solution which is exactly what I don’t want to do…

Kind Regards, Dan

Suppose 4K@60 need 8 lane and Xavier NX don’t support this configure, however if 4k@30 4 lane configure should be able supported.

Hi Shane,

Thanks for your fast response it’s greatly appreciated! So I can use the LT6911UXC with 4 lanes on the Xavier NX @ 4kp30 but not the TC358840 as it can only output 4kp30 over 8 lanes, is that correct? Sorry to be a pain with all these questions ;)

Kind Regards, Dan

Suppose yes, Xavier didn’t support gain mode(8 lanes) configure. But if TC358840 able configure as 4k@30 should be support too.

Hi Shane,

The TC358840 datasheet says it needs dual link MIPI-CSI2 to support it’s max frame rate of 4kp30 so I’m assuming this is 8 lanes and your last comment says “didn’t support gain mode(8 lanes)”. Does that mean prior to the current firmware for the Xavier NX it didn’t support 8 lanes but the current release does support it?

Kind Regards, Dan

Xavier NX does not support 8 lanes configure.

Thanks Shane,

That clears it up for me. Basically the NX can’t use 8 lanes for one source and hence the TC358840 will only work at resolutions which only require 4 lanes, so not 4k resolutions! The LT6911UXC can output 4k over 4 lanes as it has the output bandwidth of 2Gbps per lane which covers 4kp30 but probably not 4kp60. So my only solution is to use the Lontium part.

Thanks for helping me clear this up Shane, it’s greatly appreciated!

Kind Regards, Dan

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