Adding I2c TCA9545A to expand I2C buses available

How would I enable the system to recognize that there is a TCA9545A four port I2C bus switch there and handle it? I see that there are drivers for the family but how would I enable it and where would it show up?

Hi, from hardware point, I2C is master-to-slave mode, master will send out the query to address of slave, and slave will give feedback if exist.

hello lloyd_j_strickler,

you may use the sysnode to access the GPIO pins.
please also check my comments in Topic 1041755,

How would I go about using sysnode? I am new to this level of interfacing (2 weeks)

hello lloyd_j_strickler,

you should check the gpio definitions: /kernel/kernel-4.4/include/dt-bindings/gpio/tegra186-gpio.h

about accessing GPIOs via sysnode,
connect to Jetson platform, and you are able to found the GPIO pin at below path.


to generate gpio220 name for example,

cd /sys/class/gpio
echo 220 > export

set the pin direction and default value

cd /sys/class/gpio/gpio220
echo out > direction
echo 1 > value

please read the L4T documentation for more details.
you may refer to for guidance and tutorials.