examples/standalone/interrupt.c

   1 /*
   2  * (C) Copyright 2006
   3  * Detlev Zundel, DENX Software Engineering, dzu@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  *
   7  * This is a very simple standalone application demonstrating
   8  * catching IRQs on the MPC52xx architecture.
   9  *
  10  * The interrupt to be intercepted can be specified as an argument
  11  * to the application.  Specifying nothing will intercept IRQ1 on the
  12  * MPC5200 platform.  On the CR825 carrier board from MicroSys this
  13  * maps to the ABORT switch :)
  14  *
  15  * Note that the specified vector is only a logical number specified
  16  * by the respective header file.
  17  */
  18
  19 #include <common.h>
  20 #include <exports.h>
  21 #include <config.h>
  22
  23 #if defined(CONFIG_MPC5xxx)
  24 #define DFL_IRQ MPC5XXX_IRQ1
  25 #else
  26 #define DFL_IRQ 0
  27 #endif
  28
  29 static void irq_handler (void *arg);
  30
  31 int interrupt (int argc, char * const argv[])
  32 {
  33         int c, irq = -1;
  34
  35         app_startup (argv);
  36
  37         if (argc > 1)
  38                 irq = simple_strtoul (argv[1], NULL, 0);
  39         if ((irq < 0) || (irq > NR_IRQS))
  40                 irq = DFL_IRQ;
  41
  42         printf ("Installing handler for irq vector %d and doing busy wait\n",
  43                 irq);
  44         printf ("Press 'q' to quit\n");
  45
  46         /* Install interrupt handler */
  47         install_hdlr (irq, irq_handler, NULL);
  48         while ((c = getc ()) != 'q') {
  49                 printf ("Ok, ok, I am still alive!\n");
  50         }
  51
  52         free_hdlr (irq);
  53         printf ("\nInterrupt handler has been uninstalled\n");
  54
  55         return (0);
  56 }
  57
  58 /*
  59  * Handler for interrupt
  60  */
  61 static void irq_handler (void *arg)
  62 {
  63         /* just for demonstration */
  64         printf ("+");
  65 }