Dear P. Balister,
I found that tutorial which explains very well how to create a GPIO folder and
set its direction
http://www.avrfreaks.net/wiki/index.php/Documentation:Linux/GPIO#gpio-sysfs
I searched for the misc GPIOs to make sure they are free and I'm pretty sure
that over_gpio0 and overo_gpio170 are free. the are not used at all inside the
code. I connected them to debug led0 and debug_led1 and used echo 1>
/sys/class/gpio/gpio0/value after setting the direction but nothing at all, the
two debug leds are off.
Another question, what is the difference between gpio0 and gpiochip0 found at
/sys/class/gpio
Regards,
S. Yassin
HW Engineer
DLECS
________________________________
From: Philip Balister <phi...@balister.org>
To: Sameh Yassin <sameh_yassi...@yahoo.com>
Cc: GNURADIO <discuss-gnuradio@gnu.org>
Sent: Wednesday, May 2, 2012 1:33 PM
Subject: Re: [Discuss-gnuradio] E100 - Interface between OMAP3 and FPGA
On 05/01/2012 04:28 AM, Sameh Yassin wrote:
> Hello Dear ,
>
> I used the first link to use overo GPIOs on the E100 to communicate with the
> SPARTN3AN FPGA.
>
> I'm doing the following:
> 1- I chose an empty GPIO input to the FPGA (for example overo_gpio22).
> 2- I modified the FPGA image so that debug_led1 = over_gpio220
> 3- I'll set and clear overo GPIO using the bash shell as I read in the first
> link that u recommended.
>
> The problem:
> Although the following gpios are free on the FPGA. There are other gpios
>valid on the overo. Srictly speaking
>
> The free GPIOs on the overo
> $ root@usrp-e1xx:/sys/class/gpio# ls
>
> exportgpio16 gpio168 gpiochip128 gpiochip192 gpiochip64 unexport
> gpio15gpio164 gpiochip0 gpiochip160 gpiochip32 gpiochip96
It looks like you are running an older version of uhd, which suggests an
older kernel version. The older driver claimed a few extra gpio's for
testing purposes.
I see:
root@usrp-e1xx:~# ls /sys/class/gpio/
export gpio16@ gpio173@ gpiochip128@ gpiochip32@ unexport
gpio114@ gpio164@ gpio175@ gpiochip160@ gpiochip64@
gpio15@ gpio168@ gpiochip0@ gpiochip192@ gpiochip96@
Note the extra gpio's exposed to user space. These are used by uhd for
signaling and configuring the clock generator.
Philip
>
>
> The free gpios at the FPGA found at u1e.v
> input overo_gpio0, input overo_gpio14, input overo_gpio21, input
> overo_gpio22, // Misc GPIO
>
> input overo_gpio23, input overo_gpio64, input overo_gpio127, // Misc GPIO
> input overo_gpio176, input overo_gpio163, input overo_gpio170, // Misc GPIO
>
> Is that normal of I did something wrong at the kernel at the overo?
>
> Regards,
> S. Yassin
> HW Engineer
> DLECS
>
>
> ________________________________
> From: Philip Balister <phi...@balister.org>
> To: Sameh Yassin <sameh_yassi...@yahoo.com>
> Cc: "discuss-gnuradio@gnu.org" <discuss-gnuradio@gnu.org>
> Sent: Saturday, April 28, 2012 2:18 PM
> Subject: Re: [Discuss-gnuradio] E100 - Interface between OMAP3 and FPGA
>
> On 04/28/2012 08:07 AM, Sameh Yassin wrote:
>> Dear all,
>>
>> I need to send data from the OMAP3 to the Spartan3an FPGA. As I understand
>> ,from the wiki and presentations, there are two ways to communicate namely;
>> using setting_reg and GPIO. The second way seems easier so I'll try it
>> first.
>>
>> I intend to set or clear the free GPIOS on the Spartan FPGA such as
>> over_gpio_22. I added the following code to the example tx_waveforms.cpp.
>>
>> static struct gpio gpio_test = { 22, GPIOF_OUT_INIT_LOW,
>>"OVERO_GPIO_22" };
>> gpio_set_value(22,1);
>> //set gpio22 which is connected to pin IO_L30N_0
>>
>>
>> I tried to compile then I got the error that can't find GPIO.h.
>>
>> My question: did I use the correct high level function or I used a "lower
>> level" that is used to implement the function?
>
> This is the easiest way to toggle gpio's from userspace.
>
> http://wiki.gumstix.org/index.php?title=GPIO#Accessing_GPIO.27s_from_userland
>
> Also:
>
> http://elinux.org/GPIO
>
> The kernel on the e100 already supports the sysfs entries for gpio's.
> (UHD uses it)
>
> Philip
>
>>
>>
>>
>> Regards,
>> S. Yassin
>>
>>
>>
>> _______________________________________________
>> Discuss-gnuradio mailing list
>> Discuss-gnuradio@gnu.org
>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio_______________________________________________
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