Forum: GNU Radio E100 - Interface between OMAP3 and FPGA

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?



Regards,
S. Yassin

On 04/28/2012 08:07 AM, Sameh Yassin wrote:
>
> 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#Acces...

Also:

http://elinux.org/GPIO

The kernel on the e100 already supports the sysfs entries for gpio's.
(UHD uses it)

Philip

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


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 <philip@balister.org>
To: Sameh Yassin <sameh_yassin99@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:
>
> 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#Acces...

Also:

http://elinux.org/GPIO

The kernel on the e100 already supports the sysfs entries for gpio's.
(UHD uses it)

Philip

On 05/01/2012 04:28 AM, Sameh Yassin wrote:
>  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

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/Documentat...


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 <philip@balister.org>
To: Sameh Yassin <sameh_yassin99@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:
> 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

On 05/02/2012 08:16 AM, Sameh Yassin wrote:
> 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/Documentat...
>
>
> 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.
>

What version of the e100 image are you using. Can you start by making
sure you are using the latest?

http://code.ettus.com/redmine/ettus/projects/usrpe...

I think earler images will not have access to gpio0 due to some pinmux
stuff in u-boot. I need to double check 170 pinmuxing also. there should
be some free gpios in the 20's with the current image.

> Another question, what is the difference between gpio0 and gpiochip0 found at 
/sys/class/gpio

I think the gpiochip entries represent the various banks of gpios.

Philip

Hello Dear,

I've monitored the automatic boot and I think that is the latest version

U-Boot 2011.06-00575-g6b73deb (Sep 07 2011 - 07:26:10)

I also checked uname -a

3.0.0.


Regards,
S. Yassin
HW Engineer
DLECS


________________________________
 From: Philip Balister <philip@balister.org>
To: Sameh Yassin <sameh_yassin99@yahoo.com>
Cc: GNURADIO <discuss-gnuradio@gnu.org>
Sent: Wednesday, May 2, 2012 3:02 PM
Subject: Re: Using Sysfs to set a GPIO in Overo

On 05/02/2012 08:16 AM, Sameh Yassin wrote:
> 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/Documentat...
>
>
> 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.
>

What version of the e100 image are you using. Can you start by making
sure you are using the latest?

http://code.ettus.com/redmine/ettus/projects/usrpe...

I think earler images will not have access to gpio0 due to some pinmux
stuff in u-boot. I need to double check 170 pinmuxing also. there should
be some free gpios in the 20's with the current image.

> Another question, what is the difference between gpio0 and gpiochip0 found at 
/sys/class/gpio

I think the gpiochip entries represent the various banks of gpios.

Philip

Hello dear,

I followed the instruction and updated my sd card image. Now, inside 
/sys/class/gpio

$root@usrp-e1xx:/sys/class/gpio# ls
export  gpio16@  gpio173@  gpiochip128@ gpiochip32@ unexport
gpio114@ gpio164@ gpio175@  gpiochip160@ gpiochip64@
gpio15@  gpio168@ gpiochip0@ gpiochip192@ gpiochip96@

They changed from last version as us said. However, none of these are 
connected to the FPGA.
Should I try
$ echo 22 > /sys/class/gpio/export
$ echo "high" > /sys/class/gpio/gpio72/direction

or it is meaningless to create gpio "driver" in this way.

Regards,
S. Yassin
HW Engineer
DLECS


________________________________
 From: Philip Balister <philip@balister.org>
To: Sameh Yassin <sameh_yassin99@yahoo.com>
Sent: Thursday, May 3, 2012 1:30 PM
Subject: Re: Making sure of uboot version

On 05/03/2012 07:14 AM, Sameh Yassin wrote:
> Hello Dear,
>
> I've monitored the automatic boot and I think that is the latest version
>
> U-Boot 2011.06-00575-g6b73deb (Sep 07 2011 - 07:26:10)

It is not. You need to make an sd card with the e1xx-003 image on it.

See the link in the earlier email for instructions how to do this.

Philip