max80_fw/fw/irq.c

#include "picorv32.h"
#include "fw.h"
#include "console.h"

/* Invalid interrupt */
static void spurious_irq_handler(unsigned int vector)
{
    con_printf("spurious interrupt: %u\n", vector);
    mask_irq(vector);
}

/* Valid edge-triggered interrupt just to wake up waitirq */
void null_irq_handler(unsigned int vector)
{
}

/* __irq_handler_table must be in .sdata so it ends up in the zero page */
irq_handler_t __attribute__((section(".sdata")))
__irq_handler_table[IRQ_VECTORS] =
  { [0 ... IRQ_VECTORS-1] = spurious_irq_handler };

irq_handler_t register_irq(unsigned int vector, irq_handler_t handler,
			   bool enable)
{
    irq_handler_t old_handler;

    if (vector >= IRQ_VECTORS)
	return NULL;		/* Invalid vector */

    mask_irq(vector);

    if (!handler) {
	enable = false;
	handler = spurious_irq_handler;
    }
    
    old_handler = __irq_handler_table[vector];
    __irq_handler_table[vector] = handler;

    if (enable)
	unmask_irq(vector);

    if (old_handler == spurious_irq_handler)
	old_handler = NULL;

    con_printf("irq: register vector %u, handler = %p, mask = %08x\n",
	       vector, handler, irqmask());

    return old_handler;
}