SPI 3.1 enable

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

Hello folks,
I am facing one issue.
I wish to have the SPI pins enabled on my Jetson board, i.e. spidev.3.0 and spidev.3.1 need to be enabled.
I have followed this link.
https://elinux.org/Jetson/TX2_SPI
I got spidev.3.0 enabled.
I then read this link as well:

However, I am still confused and it doesn’t lead to a proper answer.
Can someone pls let me know as to how can I enable both the SPI on the Jetson TX2 board?
Any directions/ leads will be appreciated.

Thank you,
-Abhishek.

2

Something like this to enable spidev3.1

spi@3240000{
    compatible = "nvidia,tegra186-spi";
    reg = <0x0 0x3240000 0x0 0x10000>;
    ....
    ....
    ....
    linux,phandle = <0x80>;
    spi@0 {
      compatible = "spidev";
      reg = <0x0>;
      spi-max-frequency = <0x1312D00>;
      nvidia,enable-hw-based-cs;
      nvidia,cs-setup-clk-count = <0x1e>;
      nvidia,cs-hold-clk-count = <0x1e>;
      nvidia,rx-clk-tap-delay = <0x1f>;
      nvidia,tx-clk-tap-delau = <0x0>;
    }; 

    spi@1 {
      compatible = "spidev";
      reg = <0x1>;
      spi-max-frequency = <0x1312D00>;
      nvidia,enable-hw-based-cs;
      nvidia,cs-setup-clk-count = <0x1e>;
      nvidia,cs-hold-clk-count = <0x1e>;
      nvidia,rx-clk-tap-delay = <0x1f>;
      nvidia,tx-clk-tap-delau = <0x0>;
    }; 
 };
3

Thank you Shane:)

4

Hello all,

This open a /dev/spidev3.1 but it doesn’t work.

5

What’s your problem. You have to give more detail information otherwise no one can help.

6

I want to use pin 26th on j21 connector (works like chip select 1). I configured both spi (3240000)
spi@0 {
compatible = “spidev”;
reg = <0x0>;
spi-max-frequency = <0x1312D00>;
nvidia,enable-hw-based-cs;
nvidia,cs-setup-clk-count = <0x1e>;
nvidia,cs-hold-clk-count = <0x1e>;
nvidia,rx-clk-tap-delay = <0x1f>;
nvidia,tx-clk-tap-delay = <0x0>;
};
spi@1 {
compatible = “spidev”;
reg = <0x1>;
spi-max-frequency = <0x1312D00>;
nvidia,enable-hw-based-cs;
nvidia,cs-setup-clk-count = <0x1e>;
nvidia,cs-hold-clk-count = <0x1e>;
nvidia,rx-clk-tap-delay = <0x1f>;
nvidia,tx-clk-tap-delay = <0x0>;
};

I can find into dev both spi’s:
ls /dev/spi
/dev/spidev3.0 /dev/spidev3.1

But when i try to read/write trough spidev3.1 nothing happen. Chip select 1 (26th j21) always is in low level.

7

Did you probe others pin to check?

8

No, because this pin must to be root like spi chip select 1.