GPIO under Linux kernel 3.3.0+ and 3.4.67+

[DM1GP]

Dear all,

As with kernel 3.4.67+, the way to do GPIO really has changed. It took me some
time to sort it out and I like to share, what I have found out.

Because I needed the ports, I've modified the initial configuration
to use the pins on the LCD connector for GPIO as well, together
with examples for shell and C.

Because I could not manage to attach a PDF here, I uploaded
this document to my web server.

http://www.py6zgp.com/download/A20-GPIO.pdf

Please feel free to correct any error I may have made.

Hope it will be useful!


Guido
DM1GP / PY6ZGP

[JohnS]

I don't actually have one of those boards but that looks like a very useful PDF for anyone who does!

I expect Olimex would consider putting it on their web page if you ask (mail support at olimex dot com).  They'll put your name on too I expect - if you want.

It may be that the port names are not intended to have changed the way they have.  Maybe post on the linux-sunxi ML (mailing list) and ask.

(There may be useful details in the Linux Documentation for GPIO too.)

One thing is that fex files should go away (wouldn't like to guess when!) as DT (device tree) will be used instead.

John