Rockchip GPIO
Pin naming, numbering, pinctrl and using GPIO from user space with libgpiod.
Rockchip GPIOs are organised in banks of 32 pins (GPIO0–GPIO4), each split into ports A–D of 8 pins. Knowing the naming scheme lets you go from a schematic net (GPIO3_B5) to a device-tree phandle (<&gpio3 RK_PB5 …>) to a libgpiod line (gpiochip3 line 13) in seconds.
Key points
- Line offset in a bank = letter index × 8 + pin (A=0, B=1, C=2, D=3).
- Use gpioinfo / gpioset / gpioget (libgpiod) instead of the deprecated /sys/class/gpio.
- Check IO-domain voltage (1.8 V vs 3.3 V) for the bank in the io-domains node before wiring peripherals.