ROM-6881 How to use GPIO

Contents

• 1Configuration
• 2ROM-6881
• 3SOM-DB2510 Setting GPIO
• 4Test
• 5GPIO Test

Configuration

The RK3588 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. GPIO3_A0 becomes 96

ROM-6881

GPIO Number	GPIO formed	Numeric Representation
GPIO0	Ext-GPIO0 P00	493
GPIO1	Ext-GPIO0 P01	494
GPIO2	Ext-GPIO0 P02	495
GPIO3	Ext-GPIO0 P03	496
GPIO4	Ext-GPIO0 P04	497
GPIO5	GPIO4_B5	141
GPIO6	Ext-GPIO0 P05	498
GPIO7	Ext-GPIO0 P06	499
GPIO8	Ext-GPIO0 P07	500
GPIO9	GPIO4_A0	128
GPIO10	GPIO3_C0	112
GPIO11	GPIO3_C1	113

SOM-DB2510 Setting GPIO

1. Before the test, jump the GPIO0_0-GPIO0_6 and GPIO0_10 Jumper on the baseplate to 1-2.

2. Short-circuit GPIO signals on CN9 with cable

Test

Here we take GPIO0 of ROM-6881 as an example.

Export GPIO then you can use control GPIO from userr space through sysfs.

Export GPIO0

# echo 493 > /sys/class/gpio/export

Set GPIO direction to in/out

# echo "out" > /sys/class/gpio/gpio493/direction

Set GPIO value 0/1 if GPIO pin define is output

#  echo 1 > /sys/class/gpio/gpio493/value

Unexport GPIO0

# echo 493 > /sys/class/gpio/unexport

Used as IRQ signal

Note:You have to configure GPIO to input

#  echo "rising" > /sys/class/gpio/gpio493/edge

• rising: Trigger on rising edge
• falling: Trigger on falling edge
• both: Trigger on both edges
• none: Disable interrupt on both edges

GPIO Test

1. GPIO0 and GPIO1 are taken as an example: Connect GPIO0 and GPIO1

• Export GPIO0 and GPIO1

# echo 493 > /sys/class/gpio/export
# echo 494 > /sys/class/gpio/export

• Set GPIO0 to output and GPIO1 to input

# echo "out" > /sys/class/gpio/gpio493/direction
# echo "in" > /sys/class/gpio/gpio494/direction

• Change GPIO0 to 1 and read GPIO1 value

# echo 1 > /sys/class/gpio/gpio493/value
# cat /sys/class/gpio/gpio494/value 
1

• Change GPIO0 to 0 and read GPIO1 value

# echo 0 > /sys/class/gpio/gpio493/value
# cat /sys/class/gpio/gpio494/value 
0

2. Test GPIO mode 2

# /tools/test/adv/gpio/gpio_autotest.sh