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Bertrand

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GPIO names problem
« on: August 21, 2014, 07:53:38 PM »
Hello all,

My question is about the GPIO-2 connector on A10-OLinuXino-LIME.

I was reading the user manual and the schematics:
https://www.olimex.com/Products/OLinuXino/A10/A10-OLinuXino-LIME/resources/A10-OLinuXino-LIME_manual.pdf  https://github.com/OLIMEX/OLINUXINO/blob/master/HARDWARE/A10-OLinuXino-LIME/A10-OLinuXino-Lime_Rev_C.pdf

I found that the pins 17 through 29 on GPIO-2 connector have different signal names in the schematics and the user manual.
Let's take for exemple pin 29, in the schematics signal name is "PI10" and in the user manual its "PC18". Which is anoying because PC18 is already on GPIO-1 connector (schematics and user manual both agree on that).

Could you tell me what I am missing here ?

Thank you very much for your help.

brt

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Re: GPIO names problem
« Reply #1 on: September 04, 2014, 01:41:01 AM »
I was wondering why GPIO1/pin31 and GPIO2/pin29 are both documented (in A10-OlinuXino-LIME_manual.pdf) to be wired to PC18. This lead me to this thread. Looking at https://github.com/OLIMEX/OLINUXINO/blob/master/HARDWARE/A10-OLinuXino-LIME/A10_Lime_GPIOs.pdf, even though it is apparently for the older revision B of the board, that seems to make more sense.

Can anybody comment / confirm? -Bert Lindner

[edited: get the pin numbers right]

brt

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Re: GPIO names problem
« Reply #2 on: September 04, 2014, 02:58:00 AM »
Just tested the pins with a led. If I have the (mainline 3.17-rc) linux kernel gpio enumeration logic right, then it seems to match up with A10_Lime_GPIOs.pdf and not A10-OLinuXino-LIME_manual.pdf.

GPIO2 pins 9 thru 39 show up as logical gpios 256 thru 271 and if I understand the kernel numbering right from https://groups.google.com/forum/#!searchin/linux-sunxi/gpio/linux-sunxi/GjEHbncgw3s/1XSKU3w6CfMJ , these are PI0 thru PI15.

(The number of gpios per bank for sun7i/A20 does not match up with those mentioned 'for sunxi' in the patch, but the logic seems to hold).

-Bert Lindner

brt

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Re: GPIO names problem
« Reply #3 on: September 12, 2014, 12:50:31 PM »
I've recorded the mappings I found at https://docs.google.com/file/d/0B-6ABBpYc3P3ZElDSjY2R1Jzc0k, see also my post in the A20 section: https://www.olimex.com/forum/index.php?topic=3648.0

The A20 board should be the same as the A10 one, with some minor changes (the board still says 'A10-olinuxino-lime' on it), but YMMV and the above documentation may well be wrong.