TX2NX SPI transfer fails

[TrevinN]

1.How can I confirm that Pinmux has switched to SPI function
IN Jetson_TX2_NX_pinmux_config_1.05，we use the group shown in the following figure.

2.in hardware/nvidia/soc/t18x/kernel-dts/tegra186-soc/tegra186-soc-spi.dtsi
aliases {
spi0 = &spi0;
spi1 = &spi1;
spi2 = &spi2;
spi3 = &spi3;
spi4 = &aon_spi;
spi6 = &qspi6;
};

which SPI ( spi0/spi1 ) matches DTS according to the SPI shown in the above figure
3. There is no spi node under tx2nx /dev, but after loading kernel kernel 4.9 drivers spi spidev.ko, the following nodes will appear:
root@mix:/mnt/nfs# ls -l /dev/spidev
spidev0.0 spidev0.1 spidev1.0 spidev1.1
Is there a problem with dynamically loading KO? Do I need to modify some driver configurations? Can the above /dev/spi nodes be used directly? However, when I tested directly operating the above nodes, the oscilloscope did not detect any waveforms

[KevinFFF]

Hi TrevinN,

Are you using the devkit or custom board for TX2 NX?
What’s your Jetpack version in use?

@TrevinN

How can I confirm that Pinmux has switched to SPI function

Please check the column of Customer Usage as following.

It seems default used as GPIO before modification for SPI usage.

@TrevinN

which SPI ( spi0/spi1 ) matches DTS according to the SPI shown in the above figure

You could refer to tegra186-soc-spi.dtsi and get the following result:

spi0 = &spi0; //spi0: spi@3210000 {
spi1 = &spi1; //spi1: spi@c260000 {
spi2 = &spi2; //spi2: spi@3230000 {
spi3 = &spi3; //spi3: spi@3240000 {
spi4 = &aon_spi; //aon_spi: aon_spi@c260000 {
spi6 = &qspi6; //qspi6: spi@3270000 {

In your case (module pin 91, 93, 89, 95), it should mapping to spi0.
You could also refer to the following figure from design guide.

@TrevinN

after loading kernel kernel 4.9 drivers spi spidev.ko, the following nodes will appear:

It is expected due to SPI driver built as loadable kernel module and should be loaded manually.