Re: [avrdude-dev] [bug #40748] linuxgpio doesn't work on Raspberry PI rev. 2.

[René Liebscher]

Hi,

I'm sure how you can get the error you observe. In the loop pin should 
never set to 0 for open the gpio file. (value  = 0 is filtered and all 
exceptions of this are set to non-0 values.)
Could print out the relevant values in the loop so I can understand what 
going on.

Just insert the following line in the for loop:

        fprintf(stderr, "linuxgpio: i=%d, pin=%d, mask=%08x, 
inverse=%08x\n", i, pgm->pinno[i], pgm->pin[i].mask[0], 
pgm->pin[i].inverse[0]);


René



On 29.11.2013 13:19, anonymous wrote:
> URL:
>    <http://savannah.nongnu.org/bugs/?40748>
>
>                   Summary: linuxgpio doesn't work on Raspberry PI rev. 2.
>                   Project: AVR Downloader/UploaDEr
>              Submitted by: None
>              Submitted on: Fri 29 Nov 2013 12:19:14 PM UTC
>                  Category: None
>                  Severity: 3 - Normal
>                  Priority: 5 - Normal
>                Item Group: None
>                    Status: None
>                   Privacy: Public
>               Assigned to: None
>           Originator Name: Joakim Lubeck
>          Originator Email: address@hidden
>               Open/Closed: Open
>           Discussion Lock: Any
>
>      _______________________________________________________
>
> Details:
>
> I just wanted to test linuxgpio on a Raspberry PI rev. 2. I used the following
> configuration entry:
>
> ---
> programmer
>    id    = "linuxgpio";
>    desc  = "Use the Linux sysfs interface to bitbang GPIO lines";
>    type  = "linuxgpio";
>    reset = 17;
>    sck   = 2;
>    mosi  = 3;
>    miso  = 4;
> ;
> ---
>
> And used this command:
>
> ---
> sudo ./avrdude -c linuxgpio -p t1634
> Can't export GPIO 0, already exported/busy?: Device or resource busy
> ---
>
> I don't really know why, but it may be because GPIO 0 isn't available on the
> RPi rev. 2. and because of the "special handling" of GPIO 0 in linuxgpio.c.
>
> I don't have a solution but got it to work with this as a workaround:
>
> ---
> svn diff linuxgpio.c
> Index: linuxgpio.c
> ===================================================================
> --- linuxgpio.c (revision 1250)
> +++ linuxgpio.c (working copy)
> @@ -257,7 +257,7 @@
>     //that unwanted toggling of GPIO0 can occur and that other optional pins
>     //mostry LED status, can't be set to GPIO0. It can be fixed when a better
>     //solution exists.
> -  for (i=0; i<N_PINS; i++) {
> +  for (i=2; i<N_PINS; i++) {
>       if ( pgm->pinno[i] != 0 ||
>            i == PIN_AVR_RESET ||
>            i == PIN_AVR_SCK   ||
> ---
>
> /Joakim