Hi Guys,
After enable SPI1 by tegra-io utility in nano dev kit running on l4t32.3.1, I shortcut SPI_1_MOSI(J41 Pin 19) and SPI_1_MOSI(J41 Pin 21) and test by linux official spidev_test tool, it works.
sercomm:~$ sudo ./spidev_test -D /dev/spidev0.0 -v -p "test spi1"
spi mode: 0x0
bits per word: 8
max speed: 4000000 Hz (4000 KHz)
verbose=1
TX | 74 65 73 74 20 73 70 69 31 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | test.spi1
RX | 74 65 73 74 20 73 70 69 31 __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ | test.spi1
But when I test the Nano dev kit SPI1 with a slave(stm32 Nucleo), the voltage of SPI_1_CS0(J41 Pin 124) is about -1.9V, and more or less 0V same as that of GND after use the above script "sudo ./spidev_test -D /dev/spidev0.0 -v -p “test spi1”. The slave and master can’t communicate through spi1. As we all known, the CS pin of SPI1 should high or low when transfer data, that is so weird.