GPIO - which is not safe to use?

Forum: Linux
Tom 
Hello!

I need 10 GPIO pins, but I'm not sure if every pin on Mini is safe to use.
Which one I can not definitely use? I've tried to use one of GPG pins and
there was problem.

thanks in advance
best regards
Tom

Tinkerg 
Hi Tom
I know that the ones tied to the user buttons have 10k pull ups on them -
0,5,6,7 & 11 that is connector 12. I think all of the GPIO are configured
by default to be interrupts not sure thou (actually closer to a guess based
on some of the mini2440 data sheets I have looked at, one is
Mini2440Essentials.pdf it shows all as eint's as signal then GPIO as alt 1)
http://www.andahammer.com/assets/Uploads/All2440/Firmware/Mini2440Essent...
Page  7 & 8 for user buttons / Connector 12 and page 13 & 14 for connector
4 with GPIO
I am interested in what you have tried, I am looking to use 5 min and
likely more. 
Blessings
Tim

Joachim 
Hi Tom,
this is, what I found out about GPIOs.
I hope, you don't mind the german words in the table. I just copy/pasted
it.
I rebuild the kernel and use the /sys/class/gpio interface which is very
convenient. The GPIO 203 did not work on Kernel 2.6.29, which was the
default on minis with 128MB flash. All GPIOs did work on kernel 2.6.32.
If you use SuperVivi as bootloader, the GPGx should be low (0) during
startup, ohterwise the board will boot into the bootloader.
I use vboot which does not show this behaviour.

Pin  Bez.  GPIO  Bem.  ExportNr Test
9  EINT0  GPF0    160  I, O: ok
10  EINT1  GPF1    161  I, O: ok
11  EINT2  GPF2    162  I, O: ok
12  EINT3  GPF3    163  I, O: ok
13  EINT4  GPF4    164  I, O: ok
14  EINT5  GPF5    165  I, O: ok
15  EINT6  GPF6    166  I, O: ok
16  EINT8  GPG0  Button1  192  Durch Button belegt, nur I
17  EINT9  GPG1    193  I, O: ok
18  EINT11  GPG3  Button2  195  Durch Button belegt, nur I
19  EINT13  GPG5  Button3  197  Durch Button belegt, nur I
20  EINT14  GPG6  Button4  198  Durch Button belegt, nur I
21  EINT15  GPG7    199  I, O: ok
22  EINT17  GPG9    201  I, O: ok
23  EINT18  GPG10    202  I, O: ok
24  EINT19  GPG11  Button5  203  Durch Button belegt, nur I
31    GPB0    32  Da ist der Beeper angeschlossen
32    GPB1    33  I, O: ok, kein Pull-up

Regards 
Joachim