u-boot/examples/standalone/interrupt.c

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/*
* (C) Copyright 2006
* Detlev Zundel, DENX Software Engineering, dzu@denx.de.
*
* SPDX-License-Identifier: GPL-2.0+
*
* This is a very simple standalone application demonstrating
* catching IRQs on the MPC52xx architecture.
*
* The interrupt to be intercepted can be specified as an argument
* to the application. Specifying nothing will intercept IRQ1 on the
* MPC5200 platform. On the CR825 carrier board from MicroSys this
* maps to the ABORT switch :)
*
* Note that the specified vector is only a logical number specified
* by the respective header file.
*/
#include <common.h>
#include <exports.h>
#include <config.h>
#if defined(CONFIG_MPC5xxx)
#define DFL_IRQ MPC5XXX_IRQ1
#else
#define DFL_IRQ 0
#endif
static void irq_handler (void *arg);
int interrupt (int argc, char * const argv[])
{
int c, irq = -1;
app_startup (argv);
if (argc > 1)
irq = simple_strtoul (argv[1], NULL, 0);
if ((irq < 0) || (irq > NR_IRQS))
irq = DFL_IRQ;
printf ("Installing handler for irq vector %d and doing busy wait\n",
irq);
printf ("Press 'q' to quit\n");
/* Install interrupt handler */
install_hdlr (irq, irq_handler, NULL);
while ((c = getc ()) != 'q') {
printf ("Ok, ok, I am still alive!\n");
}
free_hdlr (irq);
printf ("\nInterrupt handler has been uninstalled\n");
return (0);
}
/*
* Handler for interrupt
*/
static void irq_handler (void *arg)
{
/* just for demonstration */
printf ("+");
}