/sys/devices/virtual/gpio dissapears after installing RPi.GPIO on Archlinux ARM

Question

...tinkered a bit with GPIO and Piface Digital. It was all ok until I had installed RPi.GPIO via pip. After that the directory /sys/devices/virtual/gpio disappeared and never showed up again. I had it working earlier when I installed RPi.GPIO from tar.gz.

Yesterday I made a fresh install, and there was that directory. But again, after installing RPi.GPIO over pip it disappeared again. I have removed that package, rebooted several times, deatached the Piface Digital but no luck. Don't know, what else I can do except reimaging.

Any suggestions?

Answer 1

Are you sure it's not because you have a recent kernel? I.e. have you recently updated the firmware.

The gpio directory seems to have moved to /sys/class.

ls /sys/devices/virtual

bdi    graphics  mem   net  thermal  vc      vchiq   vtconsole
block  input     misc  raw  tty      vc-cma  vc-mem  workqueue

.

ls /sys/class

bdi          ieee80211         lirc          rtc          uio
block        input             mem           scsi_device  vc
bsg          iscsi_connection  misc          scsi_disk    vc-cma
dma          iscsi_endpoint    mmc_host      scsi_host    vchiq
gpio         iscsi_host        net           sound        vc-mem
graphics     iscsi_iface       power_supply  spidev       vtconsole
hidraw       iscsi_session     raw           spi_master
i2c-adapter  iscsi_transport   rc            thermal
i2c-dev      leds              rfkill        tty

Answer 2

As @joan listed, the gpio symbolic links in /sys/class/gpio/ moved from /sys/devices/virtual/ to /sys/devices/soc/20200000.gpio.

Solution 1

chmod -R +x /sys/devices/soc/20200000.gpio

Solution 2

Update the RPi.GPIO from /sys/devices/virtual/gpio to /sys/class/gpio.

Solution 3

Add line device_tree= in /boot/config.txt. That will revert the links to be in the old path. Make sure you reboot after changing the config.txt.

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Pick your flavor :)

Edit:

I've fixed both pi-gpio (pull request #34) and gpio-admin (pull request #7) in a manner so that both the old and the new paths are supported. Hopefully, those pull requests are merged soon...