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AXI GPIO Interrupt

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Hello everyone,

i'd like to use an interrupt from a pushbutton. The buttons are connected via axi_gpio (IOCarrierCard). They works in uio in petalinux. I can read the value of the 4 pushbuttons in uio.
Now i try to detect an interrupt.
I enabled interrupts in axi_gpio ip and fabric interrupts and IRQ_F2P in zynq processing system. After that i connected them.
In the kernel config i activated "userspace i/o drivers", "userspace i/o platform driver with irq..." and "xilinx axi performance monitor driver".
My system-top.dts looks like:

&axi_gpio_0 {
ttcompatible = "generic-uio";
                interrupts = <0 29 4>;
ttinterrupt-parent = <&intc>;
t};

After booting the system and push the buttons, i don't see an interrupt with "cat /proc/interrupt" (i see  61:          0          0       GIC  61  gpio ).
I also try to write a user application and wait for an interrupt with:

int irq_count = 0;
... open and map uio ....
if(read(fd, &irq_count, 4) != 4)
t{
ttperror("read uio0");
               
t}
printf("Interrupt!");

I think after receiving an interrupt, the programm should print "Interrupt" but nothing happpens.

I followed this tutorial: http://svenand.blogdrive.com/archive/150.html#.VWRsV0YQjph


My setup:
Petalinux, SDK, Vivado 2014.4
Microzed Board with IOCarrier Card

Thanks for your answers,
Sebastian

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    Hi Sebastian,

    Hmmm, I don't have an explanation as to why all of the outputs are running together.

    I do have an idea about pressing and releasing an button generating an interrupt.  Since they are electro-mechanical switches on MicroZed IO Carrier board, there is a contact which has some springy-ness to it.  As a result, you will get some bounce effect upon the contact which could trigger multiple interrupts since the logic level would vary slightly as the contact bounced after being pressed/depressed.  You could look this up, it is sometimes debounced in software using polling or some other technique.

    Since you have the programmable logic at your disposal, you could implement debounce logic in your hardware design.  There is an example in our older "Introduction to Zynq" SpeedWay training which includes some debounce logic in verilog but you might have an idea on how to do this yourself.

    http://microzed.org/support/trainings-and-videos

    Regards,

    -Kevin

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  • 0

    Hi Sebastian,

    Hmmm, I don't have an explanation as to why all of the outputs are running together.

    I do have an idea about pressing and releasing an button generating an interrupt.  Since they are electro-mechanical switches on MicroZed IO Carrier board, there is a contact which has some springy-ness to it.  As a result, you will get some bounce effect upon the contact which could trigger multiple interrupts since the logic level would vary slightly as the contact bounced after being pressed/depressed.  You could look this up, it is sometimes debounced in software using polling or some other technique.

    Since you have the programmable logic at your disposal, you could implement debounce logic in your hardware design.  There is an example in our older "Introduction to Zynq" SpeedWay training which includes some debounce logic in verilog but you might have an idea on how to do this yourself.

    http://microzed.org/support/trainings-and-videos

    Regards,

    -Kevin

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