Subject: Re: MPC5121e, Linux, simple IO ports

From: CF Studelec <[email-masked]>
Date: Thu, 21 Mar 2013 14:44:46 +0100

Sorry to bump the post, i'm wondering if it was correctly sent.

Le 21/03/2013 09:54, CF Studelec a écrit :
> Hello,
>
> This is a simple board base on mpc5121e MCU.
>
>
> Gpio is detected: kernel is compiled with its support - i got
> gpiochip_find_base: found new base @224 in dmesg - on kernel 3.0.4.
>
>  
> But i'm unable to access it through /sys/class/gpio. I can successfully
> export a pin (ie, if i type cat 224 > export, gpio224 is created), but i
> can't successfully control it:
>
>  
>
> echo "out" > /sys/class/gpio/gpio224/direction
>
> cat /sys/class/gpio/gpio224/value
>
> 0
>
> echo 1 > /sys/class/gpio/gpio224/value
>
> cat /sys/class/gpio/gpio224/value
>
> 0
>
>  
>
> My need is a simple chipselect (well, 3 chipselect exactly ), for a
> custom design. Running linux is mandatory. I suspect the MPC5121e to be
> in the bad function mode, so:
>
> - does anyone knows how to change mode ? What register can i acces and
> how ? does it worths a try ?
>
> - does anyone successfully performed simple IO control ?
>
>  
>
> Last thing, i have tryed to access internal registers through /dev/mem,
> but no success. There are very few ressources available for this
> microcontroler, but i'm stick to it. Perhaps anybody knows how to access
> (read) internal registers with /proc or sys-fs ?
>
>  
>
> Thank you for your help.
>
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