lib_m68k/interrupts.c

   1 /*
   2  * (C) Copyright 2000-2004
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * (C) Copyright 2007 Freescale Semiconductor Inc
   6  * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
   7  *
   8  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24  * MA 02111-1307 USA
  25  */
  26
  27 #include <common.h>
  28 #include <watchdog.h>
  29 #include <asm/processor.h>
  30 #include <asm/immap.h>
  31
  32 #define NR_IRQS         (CONFIG_SYS_NUM_IRQS)
  33
  34 /*
  35  * Interrupt vector functions.
  36  */
  37 struct interrupt_action {
  38         interrupt_handler_t *handler;
  39         void *arg;
  40 };
  41
  42 static struct interrupt_action irq_vecs[NR_IRQS];
  43
  44 static __inline__ unsigned short get_sr (void)
  45 {
  46         unsigned short sr;
  47
  48         asm volatile ("move.w %%sr,%0":"=r" (sr):);
  49
  50         return sr;
  51 }
  52
  53 static __inline__ void set_sr (unsigned short sr)
  54 {
  55         asm volatile ("move.w %0,%%sr"::"r" (sr));
  56 }
  57
  58 /************************************************************************/
  59 /*
  60  * Install and free an interrupt handler
  61  */
  62 void irq_install_handler (int vec, interrupt_handler_t * handler, void *arg)
  63 {
  64         if ((vec < 0) || (vec > NR_IRQS)) {
  65                 printf ("irq_install_handler: wrong interrupt vector %d\n",
  66                         vec);
  67                 return;
  68         }
  69
  70         irq_vecs[vec].handler = handler;
  71         irq_vecs[vec].arg = arg;
  72 }
  73
  74 void irq_free_handler (int vec)
  75 {
  76         if ((vec < 0) || (vec > NR_IRQS)) {
  77                 return;
  78         }
  79
  80         irq_vecs[vec].handler = NULL;
  81         irq_vecs[vec].arg = NULL;
  82 }
  83
  84 void enable_interrupts (void)
  85 {
  86         unsigned short sr;
  87
  88         sr = get_sr ();
  89         set_sr (sr & ~0x0700);
  90 }
  91
  92 int disable_interrupts (void)
  93 {
  94         unsigned short sr;
  95
  96         sr = get_sr ();
  97         set_sr (sr | 0x0700);
  98
  99         return ((sr & 0x0700) == 0);    /* return TRUE, if interrupts were enabled before */
 100 }
 101
 102 void int_handler (struct pt_regs *fp)
 103 {
 104         int vec;
 105
 106         vec = (fp->vector >> 2) & 0xff;
 107         if (vec > 0x40)
 108                 vec -= 0x40;
 109
 110         if (irq_vecs[vec].handler != NULL) {
 111                 irq_vecs[vec].handler (irq_vecs[vec].arg);
 112         } else {
 113                 printf ("\nBogus External Interrupt Vector %d\n", vec);
 114         }
 115 }