which one is pins in hardware for /dev/i2c-0

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
5

OK, I know I haven’t been specific enough. Here it is.

Try the following command on JTX1, by which you can find the corresponding hardware register address for each /dev/i2c-?.

ubuntu@tegra-ubuntu:~$ ls -d /sys/bus/platform/devices/*.i2c/i2c-*/
/sys/bus/platform/devices/546c0000.i2c/i2c-6/
/sys/bus/platform/devices/7000c000.i2c/i2c-0/
/sys/bus/platform/devices/7000c400.i2c/i2c-1/
/sys/bus/platform/devices/7000c500.i2c/i2c-2/
/sys/bus/platform/devices/7000c700.i2c/i2c-3/
/sys/bus/platform/devices/7000d000.i2c/i2c-4/
/sys/bus/platform/devices/7000d100.i2c/i2c-5/

This matches what’s been defined in the DTSI (device tree) of JTX1. Take /dev/i2c-0 for example. It corresponds to “i2c1” (line #1306~1315) in the DTSI file.

http://nv-tegra.nvidia.com/gitweb/?p=linux-3.10.git;a=blob;f=arch/arm64/boot/dts/tegra210-soc-base.dtsi;h=930f02bfce9a6225d7946dfc03df83620ce6c5ec;hb=4206e3f9c9b3a1757c36bb798ca751c09e2db8c5

Next refer to “Tegra X1 (SoC) Technical Reference Manual” (http://developer.nvidia.com/embedded/dlc/tegra-x1-technical-reference-manual). Based on my own reading and understanding, JTX1 has been configured to “Config 1”, or “PinMux = 0”, in the pinmux table (page 609~610). From there I conclude /dev/i2c-0 corresponds to I2C_1 in the table, which in turn corresponds to GEN1_I2C.