Rock3/extlinux
Contents
Common Hardware Interfaces, I2C, PWM, SPI, UART, CAN, etc
The ROCK 3 system images use configuration file /boot/uEnv.txt.
Warning: Remember there is only one line including item "overlays=" in file /boot/uEnv.txt.
To enable I2C, PWM, SPI, UART, CAN, etc, please see RK3566/RK3568 Available Overlay (ROCK 3A, ROCK 3B, Radxa CM3) part of Device Tree Overlays
I2C
To enable I2C-2 (/dev/i2c-2), add item "rk3568-i2c2-m0" to the "overlays=" line.
overlays=rk3568-i2c2-m0
To enable I2C-3 (/dev/i2c-3), add item "rk3568-i2c3-m0" to the "overlays=" line.
overlays=rk3568-i2c3-m0
PWM
PWM0
Option 1: PWM0-M0
To enable PWM0-M0, add item "rk3568-pwm0-m0" to the "overlays=" line.
overlays=rk3568-pwm0-m0
The related directory /sys/devices/platform/fdd70000.pwm/pwm/pwmchip*
will be created.
And you can do the operation in the directory.
Option 2: PWM0-M1
To enable PWM0-M0, add item "rk3568-pwm0-m1" to the "overlays=" line.
overlays=rk3568-pwm0-m1
The related directory /sys/devices/platform/fdd70000.pwm/pwm/pwmchip*
will be created.
PWM1
PWM1-M1
To enable PWM11-M1, add item "rk3568-pwm1-m1" to the "overlays=" line.
overlays=rk3568-pwm1-m1
The related directory /sys/devices/platform/fdd70010.pwm/pwm/pwmchip*
will be created.
SPI
UART
System default enable uart2-m0 (/dev/ttyS2) to be debug console.
overlays=rk3568-fiq-debugger-uart2m0
If you want to enable uart2-m0 (/dev/ttyS2) to be normal console, modify item "rk3568-uart2-m0" to the "overlays=" line.
overlays=rk3568-uart2-m0
CAN
I2C
PWM
SPI
UART
CAN