How to use GPIO for RSB-4710
From ESS-WIKI
Configuration
The RK3399 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 : A0～A7 0-7 B0～B7 8-15 C0～C7 16-23 D0～D7 24-31
E.g. GPIO2_B0 becomes 72
RSB-4710
| GPIO Number | GPIO Formed | Numeric Representation |
| GPIO1 | GPIO2_B0 | 72 |
| GPIO2 | GPIO1_C2 | 50 |
| GPIO4 | GPIO3_D4 | 124 |
| GPIO5 | GPIO4_A4 | 132 |
| GPIO6 | GPIO0_B0 | 8 |
TEST
Export GPIO in order to use control GPIO from the user space through sysfs.
Export GPIO1.
$ echo 72 > /sys/class/gpio/export
Set GPIO direction to in/out.
$ echo "out" > /sys/class/gpio/gpio72/direction
Set GPIO value 0/1 if GPIO pin define is output.
$ echo 1 > /sys/class/gpio/gpio72/value
Used as IRQ signal
Note:You have to configure GPIO to input
$ echo "rising" > /sys/class/gpio/gpio72/edge
- rising: Trigger on rising edge
- falling: Trigger on falling edge
- both: Trigger on both edges
- none: Disable interrupt on both edges
Unexport GPIO1.
$ echo 72 > /sys/class/gpio/unexport
GPIO 1 and GPIO 2 are taken as an example:
- Connect GPIO 1 and GPIO 2.
- Export GPIO 1 and GPIO 2.
$ echo 72 > /sys/class/gpio/export $ echo 50 > /sys/class/gpio/export
- Set GPIO 1 to output.
$ echo "out" > /sys/class/gpio/gpio72/direction
- Set GPIO 2 to input
$ echo "in" > /sys/class/gpio/gpio50/direction
- Change GPIO 1 to 1 and read GPIO 2 value
$ echo 1 > /sys/class/gpio/gpio72/value $ cat /sys/class/gpio/gpio50/value 1
- Change GPIO 1 to 0 and read GPIO 2 value
$ echo 0 > /sys/class/gpio/gpio72/value $ cat /sys/class/gpio/gpio50/value 0