the R764 on the J68 of the LS1088ARDB board

root@TinyLinux:~# cat /sys/kernel/debug/gpio
gpiochip3: GPIOs 384-415, parent: platform/2330000.gpio, 2330000.gpio:

gpiochip2: GPIOs 416-447, parent: platform/2320000.gpio, 2320000.gpio:

gpiochip1: GPIOs 448-479, parent: platform/2310000.gpio, 2310000.gpio:

gpiochip0: GPIOs 480-511, parent: platform/2300000.gpio, 2300000.gpio:
root@TinyLinux:~# cd ..
root@TinyLinux:/home# cd ..
root@TinyLinux:/# ls
bin  boot  dev  etc  home  init  lib  media  mnt  proc  root  run  sbin  sys  tmp  usr  var
root@TinyLinux:/# cd sys
root@TinyLinux:/sys# cd class
root@TinyLinux:/sys/class# ls
ata_device   devfreq       hnae         mem             phy           sas_end_device  spi_master  typec_mux     vtconsole
ata_link     dma           hwmon        misc            power_supply  sas_expander    spi_slave   ubi           wakeup
ata_port     drm           i2c-adapter  mmc_host        pps           sas_host        spidev      udc           watchdog
backlight    dvb           i2c-dev      mtd             ptp           sas_phy         tee         uio
bdi          extcon        input        mux             pwm           sas_port        thermal     usb_role
block        firmware      iommu        net             regulator     scsi_device     tpm         vc
bsg          fpga_manager  leds         nvme            remoteproc    scsi_disk       tpmrm       vfio
chromeos     gpio          macvtap      nvme-subsystem  rtc           scsi_host       tty         video4linux
devcoredump  graphics      mdio_bus     pci_bus         sas_device    sound           typec       virtio-ports
root@TinyLinux:/sys/class# cd gpio
root@TinyLinux:/sys/class/gpio# echo 390 > export
root@TinyLinux:/sys/class/gpio# cd gpio390
root@TinyLinux:/sys/class/gpio/gpio390# echo in > direction // input
root@TinyLinux:/sys/class/gpio/gpio390# cat value
1
root@TinyLinux:/sys/class/gpio/gpio390# echo both > edge
root@TinyLinux:/sys/class/gpio/gpio390# cd ..
root@TinyLinux:/sys/class/gpio# more gpio390/*
::::::::::::::
gpio390/active_low
::::::::::::::
0
::::::::::::::
gpio390/consumers
::::::::::::::

*** gpio390/device: directory ***

::::::::::::::
gpio390/direction
::::::::::::::
in
::::::::::::::
gpio390/edge
::::::::::::::
both

*** gpio390/power: directory ***


*** gpio390/subsystem: directory ***

::::::::::::::
gpio390/suppliers
::::::::::::::
::::::::::::::
gpio390/uevent
::::::::::::::
::::::::::::::
gpio390/value
::::::::::::::
1
root@TinyLinux:/sys/class/gpio# cd gpio390
root@TinyLinux:/sys/class/gpio/gpio390# cat value
1
root@TinyLinux:/sys/class/gpio/gpio390# cat value
0