Enable i2c on Jetson NX dev kit 40 pin header

[mike.polia1]

I am trying to enable one or more of the I2C devices on the Jetson Xavier NX 40 pin header. I’ve been trying to do it using the jetson-io.py tool, but It is not obvious (to me at least) where to set the I2C configuration for the 40 pin header.

Also, I was expecting to have more than one I2C device available on the Dev kit. When I use the i2cdetect tool, it gives me bus/addr info only for i2c-0.

Is there a DTS file available that has the I2C configured on the 40 pin header?

Thank you.
Mike Polia

[ShaneCCC]

The I2C pin was default enable as I2C function pins, don’t need configure by jetson-io.
Which pin do you connect to? The PIN 3/5 was i2c bus 8 PIN 27/28 was bus 1

[mike.polia1]

I do not see any configuration in the DTB files that assign any of the pins of the 40 Pin header to any I2C functionality.

I would expect to see binding of the 40 pin header to I2C devices similar to the HDR40 binding for the SPI pins.

The decompiled DTS files are attached.

kernel_tegra194-p3668-0000-p3509-0000.dts (390.3 KB)
kernel_tegra194-p3668-0000-p3509-0000-user-custom.dts (392.5 KB)

[mike.polia1]

Here is the device tree generated by the running system.
devicetreebase.dts (395.6 KB)

Shouldn’t I see something like this for I2C?

		hdr40-pin19 {
			nvidia,tristate = <0x00>;
			nvidia,function = "spi1";
			nvidia,pull = <0x01>;
			nvidia,enable-input = <0x01>;
			nvidia,pins = "spi1_mosi_pz5";
			nvidia,lpdr = <0x00>;
		};

[ShaneCCC]

Like below.

				hdr40-pin3 {
27 					nvidia,pins = "dp_aux_ch3_n";
28 					nvidia,pin-label = "i2c9";
29 				};
30 				hdr40-pin5 {
31 					nvidia,pins = "dp_aux_ch3_p";
32 					nvidia,pin-label = "i2c9";
33 				};

				hdr40-pin27 {
171 					nvidia,pins = "gen2_i2c_sda_pdd0";
172 				};
173 				hdr40-pin28 {
174 					nvidia,pins = "gen2_i2c_scl_pcc7";
175 				};