[MinnowBoard] Echo to MinnowBoardMax GPIO export fails

[Darren Hart]

Thank you John,

So now we need to sort out if this is some configuration delta that I'm
ignorant of, or if Ubuntu is being clever.

For those of you experiencing problems here, do you have anything else
connected to the board? Any GPIO expanders or devices which might have
GPIOs? I'm assuming not, but it's worth checking.

On an Ubuntu kernel, can someone send me the output of:

$ ls /sys/class/gpio/gpiochip*/

Or perhaps:

$ tree /sys/class/gpio

Thanks,

-- 
Darren Hart
Intel Open Source Technology Center




On 1/7/15, 5:32 PM, "John Hawley" <john.hawley at intel.com> wrote:

>Ok I spent a little bit of time digging into this, it *LOOKS* like
>Ubuntu is offset by +256 vs. stock and/or Fedora kernels.  Not 100% sure
>why yet.
>
>That being said I wrote up a quick script that should discover the right
>values for everything and output it to a text console:
>
>https://github.com/warthog9/minnow-max-extras/blob/master/lse/what_gpio_nu
>m.sh
>
>and I've got a merge request in with it (I'll let Darren have a look at
>it and yell at me about it before it gets merged).
>
>If you are having problems, can you run that script and let me know if
>the output is right for you?  In the meantime I'll try and dig into why
>the offset.
>
>- John 'Warthog9' Hawley
>
>On 01/07/2015 06:51 AM, Michael Jones wrote:
>> Martin,
>> 
>> Very helpful, thanks. I had to think a bit to understand the base of 82
>>and 154.
>> 
>> For others:
>> 
>> For 8x, Code GPIO# = 338 + Linux GPIO# (Chart) - 82
>> For 2x, Code GPIO# = 410 + Linux GPIO# (Chart) - 154
>> 
>> So for the two examples:
>> 
>> 338 + 84 - 82 = 340
>> 
>> and
>> 
>> 410 + 208 - 154 = 464
>> 
>> I¹ll give this a try later this week.
>> 
>> Are there any proper ways to expose the /sys paths for user mode like
>>one can do for /dev/ttyN? Or do people just run their code as root?
>> 
>> Mike
>> 
>> 
>> On Jan 5, 2015, at 7:29 AM, Martin Oldfield
>><elinux-mbmx-2014-11 at mjoldfield.com> wrote:
>> 
>>> I've also found wildly different GPIO numbers on my Minnowboard Max.
>>>
>>> You can read about it at
>>> http://www.mjoldfield.com/atelier/2014/12/mbmx-gpio.html.
>>>
>>>
>>>
>>> --
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>>>http://minnowboard.57273.x6.nabble.com/MinnowBoard-Echo-to-MinnowBoardMa
>>>x-GPIO-export-fails-tp903p907.html
>>> Sent from the MinnowBoard mailing list archive at Nabble.com.
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>> 
>> 
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