Jetson Nano, Enable spi1 and spi2 in the device tree

[bf1]

Hi,
I know that I can use jetson-io.
But I want also to modify some uart parameters that I cannot with jetson-io.
I want to modify the dma mode to rx, tx in order to comply with this post :

ttyTHS2 filling with 0x00

Every few hours of run time (3-4 hours), I see /dev/ttyTHS2 fill with 0x00 in place of the actual data coming from a GPS module. I’ve set UART traces on the GPS module itself to confirm the module is not the one sending 0x00. In user space I made some logs to output what was being read from /dev/ttyTHS2 and confirmed this behavior with a hexdump on /dev/ttyTHS2. Below is an example of the log output. ERROR imu - [16341588] Unexpected header 0x0 ERROR imu - [16341591] Unexpected GPS chara…

(solution found by AS409 contributor).
So if I need to modify DT, by the way I want to enable spi1 and spi2.

Is there a clear and step-by-step doc do modify DT and waht file to modifiy to do that?

regards