irq_test.c

Linux device driver sample code

#include <linux/interrupt.h>
#include <linux/module.h>
#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/mach/irq.h>

void do_irq30_tasklet(unsigned long param)
{
	printk(KERN_INFO "IRQ30 Tasklet \n");
}

DECLARE_TASKLET(irq30_tasklet, do_irq30_tasklet, 0);

int aic_set_type(unsigned irq, unsigned type)
{
    unsigned int smr, srctype;

    switch (type) {
    case IRQT_HIGH:
        srctype = AT91_AIC_SRCTYPE_HIGH;
        break;
    case IRQT_RISING:
        srctype = AT91_AIC_SRCTYPE_RISING;
        break;
#if 0
    case IRQT_LOW:
        if ((irq == AT91_ID_FIQ) || is_extern_irq(irq))     /* only supported on external interrupts */
            srctype = AT91_AIC_SRCTYPE_LOW;
        else
            return -EINVAL;
        break;
    case IRQT_FALLING:
        if ((irq == AT91_ID_FIQ) || is_extern_irq(irq))     /* only supported on external interrupts */
            srctype = AT91_AIC_SRCTYPE_FALLING;
        else
            return -EINVAL;
        break;
#endif
    default:
        return -EINVAL;
    }

    smr = at91_sys_read(AT91_AIC_SMR(irq)) & ~AT91_AIC_SRCTYPE;
    at91_sys_write(AT91_AIC_SMR(irq), smr | srctype);
    return 0;
}

irqreturn_t myIRQ(int irq, void *devid)
{
	printk(KERN_INFO "IRQ test");

	tasklet_schedule(&irq30_tasklet);

	return IRQ_HANDLED;
}

int init_module(void)
{
	int ret;
	
	aic_set_type(30, IRQT_RISING);

	ret = request_irq(30, myIRQ, 0, "MYIRQ", 0);
	
	return 0;	
}

void cleanup_module(void)
{
	free_irq(30, 0);
}

/*
 * 	*PIOC_BSR = *PIOC_BSR | 0x00008000;  //Enable IRQ functionality
 * 	*PIOC_PDR = *PIOC_PDR | 0x00008000;  //Disable GPIO functionality.
 */