How to use SPI? Can you tell me brief steps?

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

Hi.

Since last month, I frequently ask about kernel & SPI.

Thanks to “linuxdev”, build kernel process is partially solved.
(But I still need to ask more (;_;))

Before study more about build kernel, I want to ask you people about breif step for using SPI on AGX DevKit.

For example.

  1. GPIO MUX setting(use GPIO MUX configuration .xls file from NVIDIA)
  2. Configure Device tree
  3. Build source
  4. Flash it to AGX.
    .
    .
    .

Like this.

In my situation, I can’t draw any blueprint about using SPI
(I’m expert to using Microcontroller such as TI C2000 MCU, AVR… etc )
(But I’m super newbie to Linux systems like RPi, Jetson…)

Can you help me to understand the way to develope SPI on AGX Xavier?

Thanks.

3

Have a reference to below link.

4

Can you tell me I’m wrong or right?

  1. Set pinmux using pinmux.xlxs from NVIDIA.
  2. Modify device tree
  3. Build kernel with modified PINMUX & Device tree.
  4. Flash kernel things to AGX.
  5. And some software level check & develope SPI code.

is it right?

5

Yes, that should be correct.

Also you need to flash whole system to update the cfg file. -k wouldn’t apply the cfg file.