GPIO_ROM-5880_
The RK3568 bank/bit notation for GPIOs must be formed as “GPIO<GPIO_ bank>_<gpio_bit>”. The numeric value of GPIO is calculated as follows: 32 x (gpio_bank) + gpio_bit gpio_bit: A0A7 0-7 B0B7 8-15 C0C7 16-23 D0D7 24-31 E.g. GPIO2_D0 becomes 88
ROM-5880 GPIO

SOM-DB2510 GPIO Pin header:

Export GPIO then you can use control GPIO from user space through sysfs. Export GPIO
# echo 88 > /sys/class/gpio/export
Set GPIO direction to in/out
# echo "out" > /sys/class/gpio/gpio88/direction
Set GPIO value 0/1 if GPIO pin define is output
# echo 1 > /sys/class/gpio/gpio88/value
Used as IRQ signal
# echo "rising" > /sys/class/gpio/gpio88/edge
NOTE: You have to configure GPIO to input. rising: Trigger on rising edge falling: Trigger on falling edge both: Trigger on both edges none: Disable interrupt on both edges
Unexport GPIO
# echo 88 > /sys/class/gpio/unexport
GPIO0 and GPIO1 are taken as an example: Connect GPIO0 and GPIO1
Export GPIO0 and GPIO1
# echo 88 > /sys/class/gpio/export
# echo 89 > /sys/class/gpio/export
Set GPIO0 to output and GPIO1 to input
# echo "out" > /sys/class/gpio/gpio88/direction
# echo "in" > /sys/class/gpio/gpio89/direction
Change GPIO0 to 1 and read GPIO1 value
# echo 1 > /sys/class/gpio/gpio88/value
# cat /sys/class/gpio/gpio89/value
1
Change GPIO0 to 0 and read GPIO2 value
# echo 0 > /sys/class/gpio/gpio88/value
# cat /sys/class/gpio/gpio89/value
0