ECE497 Notes on gpio-keys

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thumb‎ Embedded Linux Class by Mark A. Yoder


I'm trying to figure out how to access the USER button on the Beagle xM. It looks like the new versions of the SD image use gpio-keys to manage gpio 4 so you can't access it via

beagle$ cd /sys/class/gpio
beagle$ echo 4 > export
bash: echo: write error: Device or resource busy

You need to access it via evtest, but I don't see a way to do it via the shell.

References

  • Here Jason suggests looking at evtest.c to learn how to access the USER button.
  • Here are some details on evtest.




thumb‎ Embedded Linux Class by Mark A. Yoder