SPI with external device

I’m using Jetson Nano B01 to control my camera module through SPI, and I have enabled SPI0 use jetson-io.py method, the loopback test showed correctly.
But when I connected the MOSI, MISO, CS0 and SCK between camera module and Jetson Nano, then sent date from MOSI pin following the camera introduction to enable it, I didn’t get any data feedback, the oscilloscope detected data being sent from MOSI, but the MISO received only ZERO.
The camera module has been working correctly on other MCUs, so it’s at good condition.
Do I have to add the camera driver & device or add it to device tree, as the SPI has been enabled?

What is the voltage on the SPI lines? I had an issue where the current drive of the Jetson Nano GPIO pins is not high enough.

Could you reference to the …/kernel/nvidia/drivers/media/spi/imx204.c for SPI sensor driver to implement your driver to confirm it.

Hi, the voltage is shown below:
SPI_1_MOSI(pin19) is 1.7V.
SPI_1_MISO(pin21) is 1.6V.
SPI_1_SCK(pin23) is near zero.
SPI_1_CS0(pin24) is 1.6V.
SPI_1_CS1(pin26) is near zero.

I am not using imx204 camera, do I still have to refer that imx204.c file?

I think if the loopback test working well the pin configure should be fine for it.

The loopback works with a little problem, the test file send 38 bytes data, and receive 38 bytes, but every time there are 1-2 bytes of data not correct.