SPI port indexing confusion

Robotics & Edge Computing Jetson Systems Jetson TX2
1

Hi

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?

3

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

4

Hi.

I am waiting for a response.

Thanks.

5

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

6

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?

7

Suppose yes

8

Thanks