How to use GPIO RK3568

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Configuration

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 : A0~A7 0-7 B0~B7 8-15 C0~C7 16-23 D0~D7 24-31

E.g. GPIO3_A0 becomes 96

RSB-4810

GPIO Number GPIO formed Numeric Representation
GPIO1
GPIO3_A0
96
GPIO2
GPIO3_A2
98
GPIO3
GPIO3_A3
99
GPIO4
GPIO3_A4
100
GPIO5
GPIO3_A5
101
GPIO6
GPIO3_A6
102


ROM-5880

GPIO Number GPIO formed Numeric Representation
GPIO0 GPIO2_D0 88
GPIO1 GPIO2_D1 89
GPIO2 GPIO2_D2 90
GPIO3 GPIO2_D3 91
GPIO4 GPIO2_C6 86
GPIO5 GPIO3_A1 97
GPIO6 GPIO3_A7 103
GPIO7 GPIO3_B0 104
GPIO8 GPIO3_B1 105
GPIO9 GPIO3_B2 106
GPIO10 GPIO3_B3 107
GPIO11 GPIO3_B4 108

Test

Here we take GPIO1 of 4810 as an example.

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

Export GPIO1

# echo 96 > /sys/class/gpio/export

Set GPIO direction to in/out

# echo "out" > /sys/class/gpio/gpio96/direction

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

#  echo 1 > /sys/class/gpio/gpio96/value

Used as IRQ signal

Note:You have to configure GPIO to input

#  echo "rising" > /sys/class/gpio/gpio96/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 96 > /sys/class/gpio/unexport

Test

GPIO1 and GPIO2 are taken as an example:

  • Connect GPIO1 and GPIO2
  • Export GPIO1 and GPIO2
# echo 96 > /sys/class/gpio/export
# echo 98 > /sys/class/gpio/export
  • Set GPIO 1 to output
# echo "out" > /sys/class/gpio/gpio96/direction
  • Set GPIO 2 to input
# echo "in" > /sys/class/gpio/gpio98/direction
  • Change GPIO1 to 1 and read GPIO2value
# echo 1 > /sys/class/gpio/gpio96/value
# cat /sys/class/gpio/gpio98/value 
1
  • Change GPIO1 to 0 and read GPIO2 value
# echo 0 > /sys/class/gpio/gpio96/value
# cat /sys/class/gpio/gpio98/value 
0