examples/interrupt.c

   1 /*
   2  * (C) Copyright 2006
   3  * Detlev Zundel, DENX Software Engineering, dzu@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  *
  23  * This is a very simple standalone application demonstrating
  24  * catching IRQs on the MPC52xx architecture.
  25  *
  26  * The interrupt to be intercepted can be specified as an argument
  27  * to the application.  Specifying nothing will intercept IRQ1 on the
  28  * MPC5200 platform.  On the CR825 carrier board from MicroSys this
  29  * maps to the ABORT switch :)
  30  *
  31  * Note that the specified vector is only a logical number specified
  32  * by the respective header file.
  33  */
  34
  35 #include <common.h>
  36 #include <exports.h>
  37 #include <config.h>
  38
  39 #if defined(CONFIG_MPC5xxx)
  40 #define DFL_IRQ MPC5XXX_IRQ1
  41 #else
  42 #define DFL_IRQ 0
  43 #endif
  44
  45 static void irq_handler (void *arg);
  46
  47 int interrupt (int argc, char *argv[])
  48 {
  49         int c, irq = -1;
  50
  51         app_startup (argv);
  52
  53         if (argc > 1)
  54                 irq = simple_strtoul (argv[1], NULL, 0);
  55         if ((irq < 0) || (irq > NR_IRQS))
  56                 irq = DFL_IRQ;
  57
  58         printf ("Installing handler for irq vector %d and doing busy wait\n",
  59                 irq);
  60         printf ("Press 'q' to quit\n");
  61
  62         /* Install interrupt handler */
  63         install_hdlr (irq, irq_handler, NULL);
  64         while ((c = getc ()) != 'q') {
  65                 printf ("Ok, ok, I am still alive!\n");
  66         }
  67
  68         free_hdlr (irq);
  69         printf ("\nInterrupt handler has been uninstalled\n");
  70
  71         return (0);
  72 }
  73
  74 /*
  75  * Handler for interrupt
  76  */
  77 static void irq_handler (void *arg)
  78 {
  79         /* just for demonstration */
  80         printf ("+");
  81 }