On 06/07/2012 11:16 PM, Chris Stone wrote:
I am using Xenomai 2.6.0 on kernel 3.0.13, with 
adeos-ipipe-3.0.13-powerpc-2.13-06 applied. My target CPU
is Freescale MPC8378.

On a powerpc, GPIO's are mapped to virtual irqs. Thus, in order to install an 
irq handler for a gpio
interrupt, one must do the following in the kernel:

        err = gpio_request(HYPHY_IRQ_GPIO, NULL);
        if (err<0) {
                printk(KERN_ERR "%s: could not request gpio %d, rc %d\n", 
__func__, HYPHY_IRQ_GPIO, err);
                return err;
        }
        err = gpio_direction_input(HYPHY_IRQ_GPIO);
        if (err<0) {
                printk(KERN_ERR "%s: could not set gpio %d to input, rc %d\n", 
__func__, HYPHY_IRQ_GPIO, err);
                return err;
        }

        virq = __gpio_to_irq(HYPHY_IRQ_GPIO);
        if (virq<  0) {
                printk(KERN_ERR "%s: could not map gpio %d to virq \n", 
__func__, HYPHY_IRQ_GPIO);
                return virq;
        }
       err = request_irq(virq, hyphy20G_irq, 0, 
hyphy20G_dev.name,&hyphy20G_dev);

In other words, you install the irq handler on the virtual irq number returned 
from __gpio_to_irq. The above
code works in my system, i.e., the hyphy20G_irq handler is called on an 
interrupt.

However, if I use:

err = rt_intr_create(intrObj, "HyPhyIRQ", virq, hyphy20G_irq, NULL, 0);
rt_intr_enable(intrObj);

then the hyphy20G_irq handler is not called on an interrupt. I realize that 
interrupt handlers are
recommended to be implemented in user space, but a user space implementation 
does not work either,

I believe this is a typo, but just for the record: the rt_intr* API is deprecated, and interrupt handlers in user-space over Xenomai are NOT recommended.

so I moved into the kernel to see if I could get something to work.

Is it possible to install an Xenomai ISR on a powerpc virtual irq?

Xenomai, and more specifically the I-pipe does interface with irq numbers defined in the kernel namespace, so yes, virqs is what we always use internally for powerpc.

You may want to check whether that GPIO is actually chained from a multiplex parent IRQ.

--
Philippe.

_______________________________________________
Xenomai mailing list
[email protected]
http://www.xenomai.org/mailman/listinfo/xenomai

Reply via email to