i use a external pull-up to read a gpio pin with my code in c .
to test if it is possible use a pin with internal pull-up (without external), how can i enable and set internal pull-up?
Thanks
At First
disclaimer: i never tested pull-up configuration on my Olimex board.
To your question, it depends on the Kernel version
Freescale downstream kernel 2.6.35: look at the board config code
Mainline kernel > 3.x: look at the devicetree source (http://lxr.free-electrons.com/source/arch/arm/boot/dts/imx23-olinuxino.dts) and binding doc (http://lxr.free-electrons.com/source/Documentation/devicetree/bindings/pinctrl/fsl,mxs-pinctrl.txt)
Looking at the i.MX23 reference manual shows only a few pins on Olimex boards have configurable pull-ups like GPMI_CE0N and GPMI_CE1N (10 k).