GHRD interrupts

I have the Arrow SoCkit, and I have been struggling with this for a while. I'm digging into the device tree for the arrow board posted on rocketboards, and I found an entry for the gpio's.

agpio0: gpio@0xc0000000 {

compatible = "altr,pio-1.0";

/* Register base 0xff200000 is for a light-weight bridge */

reg = <0xff200000 0x10>;

width = <32>;

/* There are 64 interrupts from the FPGA start at 72, so 45 has to be wrong */

interrupts = <0 45 4>;

interrupt-controller;

# interrupt-cells = <1>;

gpio-controller;

# gpio-cells = <2>;

level_trigger = <0>;

I verified this is what the Linux kernel sees by looking in the folder at /proc/device-tree/soc/gpio@0xc0000000

I'm worried about the comment : /* There are 64 interrupts from the FPGA start at 72, so 45 has to be wrong */

I wonder why that has to be wrong?

This looks different from the Altera boards device tree entry, which is:

button_pio: gpio@0x100c0 {

compatible = "ALTR,pio-13.0.1", "ALTR,pio-1.0", "altr,pio-1.0";

reg = < 0x000100C0 0x00000010 >;

interrupt-parent = < &hps_0_arm_gic_0 >;

interrupts = < 0 41 1 >;

width = < 2 >; /* width type NUMBER */

resetvalue = < 0 >; /* resetValue type NUMBER */

level_trigger = < 0 >; /* embeddedsw.dts.params.level_trigger type NUMBER */

# gpio-cells = < 2 >;

gpio-controller;

}; //end gpio@0x100c0 (button_pio)

This entry has quite few differences from the arrow version.

I have tried following the example here: C:\altera\13.0sp1\embedded\examples\software\Altera-SoCFPGA-Push-Button-Linux-GNU.tar.gz

I was able to build the gpio-interrupt driver in the example. I used the yocto project kernel headers for the altera board to build against. (Not sure if this was the right way to do this.)

For the arrow board, when I insert the altera-gpio.ko kernel module, ( with 'modprobe gpio_altera'), I find gpiochip224 in /sys/class/gpio.

The next step I did was insert the gpio-interrupt kernel module I built from the example with the command 'modprobe gpio_interrupt gpio_number=224'

So I look at /proc/interrupts and I see this:

CPU0 CPU1

525: 123056 121886 GIC twd

648: 1 0 GIC eth0

656: 1 0 GIC dwc_otg, dwc_otg_pcd, d

667: 2280 0 GIC dw-mci

679: 0 0 GIC ff705000.spi

682: 0 0 GIC dw_spi0

684: 0 0 GIC dw_spi1

686: 0 0 GIC ffc04000.i2c

687: 0 0 GIC ffc05000.i2c

690: 6879 0 GIC serial

697: 9 0 GIC timer2

752: 0 0 altera-gpio (null)

IPI0: 0 0 CPU wakeup interrupts

IPI1: 0 0 Timer broadcast interrupts

IPI2: 1127 1196 Rescheduling interrupts

IPI3: 0 0 Function call interrupts

IPI4: 1 2 Single function call interrupts

IPI5: 0 0 CPU stop interrupts

Err: 0

There is an entry for the altera-gpio interrupt, but it does respond when I push the button (No updating /proc/interrupts, and no message in 'dmesg')

The '(null)' after the interrupt is concerning.

Any help is appreciated.

Thanks.

Hi ecullert

I have writen a hps gpio interrupt driver with kernel-3.8. I build the driver within the kernel and it works.

I get the kernel source from http://www.rocketboards.org/foswiki/view/projects/sockitlinarolinuxdesktop

In the dts I just add myself code

gpio1: gpio@0xff709000 {

compatible = "key";

reg = < 0xff709000 0x00001000 >;

interrupts = <0 165 4>;

};

The interrupt number in dts is 32 less than the number in GIC

The I write my own driver (initial the driver and register the interrupt in kernel)

This driver just uste the gpio interrupt but not fpga interrupt

I hope the information be helpful for you!

Hi,

Can someone please give some help on how to actually use the interrupt. I have a FIFO setup connected the light weight avalon master. The interrupt from the FIFO is connected to the HPS.

But how do I set up the device tree.

I read up somewhere to generate the device tree file from the sopcinfo file. I tried doing this but I got the following response.

"Master and slave interfaces for the Transparent bridge in fifo_0 of type altera_avalon_fifo have different types."

Any thoughts?

Jack

@ecullert

Thank you for your very detailled help.

I have done a "make" with linux-altera-3.7.

Everything works fine in my virtual machine but not on my Evaluation Board.

The Problem:

I get an error for "insmod gpio_interruot.ko" because I should use kernel version 3.8.0.

Is there an altera-linux-3.8?

I have not found anything on Google.

Best regards,

Michael

As far as I can tell, the altera yocto source package is still on 3.7. You could build the 3.7 Linux and do your testing unless there is a reason you need 3.8.

The following webpages should get you through the entire process.

http://www.rocketboards.org/foswiki/documentation/gsrdgettingstartedyocto

http://www.rocketboards.org/foswiki/documentation/gsrdsdcard