SPI port indexing confusion


I enabled the SPI port using Jetson-IO tool.

The SPI1 port of Jetson-TX2 is referred with three different index!

  • spidev3.0 (and 3.1) in linux (dmesg) , and this index should be used in python code

  • spi4 in Jetson-IO tool

  • SPI1 in P2597 schematic and Jetson module datasheet.

Is there any hidden relation between indexes for someone who wants to understand this?

Sorry for the late response, our team will do the investigation and provide suggestions soon. Thanks


I am waiting for a response.


Get the PinMux Spreadsheet and check the Column 1 like SPI1_CLK and Column 5/6/7 to find the function configure like SPI4_CLK,
The SPI4_* is the HW function name start from 1 and minus 1 to get software bus due to started from 0.
So you can get the SPI1_* is the /dev/spidev3.x

According to what you said, I conclude the following:

Jetson SOM connector name    -    SFIO or configured function name   -   linux spidev name

         SPI1               -                   SPI4                -        spidev3.x
         SPI2               -                   SPI1                -        spidev0.x
         SPI0               -                   SPI2                -        spidev1.x

Is the “minus 1” rule documented anywhere?

Suppose yes


This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.