GPIO

The current state of the system’s GPIOs can be obtained in user-mode, as shown in the following example:

root@neuralplex:~# gpiodetect
gpiochip0 [5d080000.gpio] (32 lines)
gpiochip1 [5d090000.gpio] (32 lines)
gpiochip2 [5d0a0000.gpio] (32 lines)
gpiochip3 [5d0b0000.gpio] (32 lines)
gpiochip4 [5d0c0000.gpio] (32 lines)
gpiochip5 [5d0d0000.gpio] (32 lines)
gpiochip6 [5d0e0000.gpio] (32 lines)
gpiochip7 [5d0f0000.gpio] (32 lines)


gpiodetect	List all gpiochips present on the system, their names, labels and number of GPIO lines
gpioinfo	List all lines of specified gpiochips, their names, consumers, direction, active state and additional flags
gpioget	Read values of specified GPIO lines
gpioset	Set values of specified GPIO lines, potentially keep the lines exported and wait until timeout, user input or signal
gpiofind	Find the gpiochip name and line offset given the line name
gpiomon	Wait for events on GPIO lines, specify which events to watch, how many events to process before exiting or if the events should be reported to the console

gpioinfo

root@neuralplex:~# gpioinfo -c4
gpiochip4 - 32 lines:
  line   0:  "                   "  input
  line   1:  "                   "  output active-low consumer="enable"
  line   2:  "                   "  input
  line   3:  "usb3-hub-reset     "  input
  line   4:  "                   "  input
  line   5:  "                   "  input
  line   6:  "                   "  input
  line   7:  "                   "  input
  line   8:  "                   "  input
  line   9:  "                   "  input
  line  10:  "                   "  input
  line  11:  "                   "  input
  line  12:  "sd-card-detect     "  input active-low consumer="cd"
  line  13:  "                   "  input
  line  14:  "                   "  input
  line  15:  "                   "  input
  line  16:  "                   "  input
  line  17:  "                   "  input
  line  18:  "                   "  input
  line  19:  "wlreg_on           "  input
  line  20:  "bluetooth-disable  "  input
  line  21:  "                   "  input
  line  22:  "cellular-disable   "  input
  line  23:  "                   "  output
  line  24:  "audio-reset        "  input
  line  25:  "cellular-reset     "  input
  line  26:  "gps-reset          "  input
  line  27:  "pcie0-clkreq-b     "  output active-low consumer="enable"
  line  28:  "pcie01-wake-b      "  input
  line  29:  "pcie0-reset-b      "  input
  line  30:  "pcie1-clkreq-b     "  input
  line  31:  "                   "  input

gpioget

The gpioget utility can be used to manipulate GPIO from the command line.

For example, to read the value of the audio-reset GPIO pin:

root@neuralplex:~# gpioget -c4 24
"24"=inactive

gpioset

The gpioset utility can be used to manipulate GPIO from the command line.

For example, to set the value of the audio-reset GPIO pin:

root@neuralplex:~# gpioset -c4 24=1