arch/i386/lib/interrupts.c

   1 /*
   2  * (C) Copyright 2009
   3  * Graeme Russ, <graeme.russ@gmail.com>
   4  *
   5  * (C) Copyright 2007
   6  * Daniel Hellstrom, Gaisler Research, <daniel@gaisler.com>
   7  *
   8  * (C) Copyright 2006
   9  * Detlev Zundel, DENX Software Engineering, <dzu@denx.de>
  10  *
  11  * (C) Copyright -2003
  12  * Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
  13  *
  14  * (C) Copyright 2002
  15  * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
  16  *
  17  * (C) Copyright 2001
  18  * Josh Huber, Mission Critical Linux, Inc, <huber@mclx.com>
  19  *
  20  * See file CREDITS for list of people who contributed to this
  21  * project.
  22  *
  23  * This program is free software; you can redistribute it and/or
  24  * modify it under the terms of the GNU General Public License as
  25  * published by the Free Software Foundation; either version 2 of
  26  * the License, or (at your option) any later version.
  27  *
  28  * This program is distributed in the hope that it will be useful,
  29  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  31  * GNU General Public License for more details.
  32  *
  33  * You should have received a copy of the GNU General Public License
  34  * along with this program; if not, write to the Free Software
  35  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  36  * MA 02111-1307 USA
  37  */
  38
  39 /*
  40  * This file contains the high-level API for the interrupt sub-system
  41  * of the x86 port of U-Boot. Most of the functionality has been
  42  * shamelessly stolen from the leon2 / leon3 ports of U-Boot.
  43  * Daniel Hellstrom, Detlev Zundel, Wolfgang Denk and Josh Huber are
  44  * credited for the corresponding work on those ports. The original
  45  * interrupt handling routines for the x86 port were written by
  46  * Daniel Engström
  47  */
  48
  49 #include <common.h>
  50 #include <asm/interrupt.h>
  51
  52 struct irq_action {
  53         interrupt_handler_t *handler;
  54         void *arg;
  55         unsigned int count;
  56 };
  57
  58 static struct irq_action irq_handlers[CONFIG_SYS_NUM_IRQS] = { {0} };
  59 static int spurious_irq_cnt = 0;
  60 static int spurious_irq = 0;
  61
  62 void irq_install_handler(int irq, interrupt_handler_t *handler, void *arg)
  63 {
  64         int status;
  65
  66         if (irq < 0 || irq >= CONFIG_SYS_NUM_IRQS) {
  67                 printf("irq_install_handler: bad irq number %d\n", irq);
  68                 return;
  69         }
  70
  71         if (irq_handlers[irq].handler != NULL)
  72                 printf("irq_install_handler: 0x%08lx replacing 0x%08lx\n",
  73                        (ulong) handler,
  74                        (ulong) irq_handlers[irq].handler);
  75
  76         status = disable_interrupts ();
  77
  78         irq_handlers[irq].handler = handler;
  79         irq_handlers[irq].arg = arg;
  80         irq_handlers[irq].count = 0;
  81
  82         unmask_irq(irq);
  83
  84         if (status)
  85                 enable_interrupts();
  86
  87         return;
  88 }
  89
  90 void irq_free_handler(int irq)
  91 {
  92         int status;
  93
  94         if (irq < 0 || irq >= CONFIG_SYS_NUM_IRQS) {
  95                 printf("irq_free_handler: bad irq number %d\n", irq);
  96                 return;
  97         }
  98
  99         status = disable_interrupts ();
 100
 101         mask_irq(irq);
 102
 103         irq_handlers[irq].handler = NULL;
 104         irq_handlers[irq].arg = NULL;
 105
 106         if (status)
 107                 enable_interrupts();
 108
 109         return;
 110 }
 111
 112 void do_irq(int hw_irq)
 113 {
 114         int irq = hw_irq - 0x20;
 115
 116         if (irq < 0 || irq >= CONFIG_SYS_NUM_IRQS) {
 117                 printf("do_irq: bad irq number %d\n", irq);
 118                 return;
 119         }
 120
 121         if (irq_handlers[irq].handler) {
 122                 mask_irq(irq);
 123
 124                 irq_handlers[irq].handler(irq_handlers[irq].arg);
 125                 irq_handlers[irq].count++;
 126
 127                 unmask_irq(irq);
 128                 specific_eoi(irq);
 129
 130         } else {
 131                 if ((irq & 7) != 7) {
 132                         spurious_irq_cnt++;
 133                         spurious_irq = irq;
 134                 }
 135         }
 136 }
 137
 138 #if defined(CONFIG_CMD_IRQ)
 139 int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 140 {
 141         int irq;
 142
 143         printf("Spurious IRQ: %u, last unknown IRQ: %d\n",
 144                spurious_irq_cnt, spurious_irq);
 145
 146         printf ("Interrupt-Information:\n");
 147         printf ("Nr  Routine   Arg       Count\n");
 148
 149         for (irq = 0; irq <= CONFIG_SYS_NUM_IRQS; irq++) {
 150                 if (irq_handlers[irq].handler != NULL) {
 151                         printf ("%02d  %08lx  %08lx  %d\n",
 152                                         irq,
 153                                         (ulong)irq_handlers[irq].handler,
 154                                         (ulong)irq_handlers[irq].arg,
 155                                         irq_handlers[irq].count);
 156                 }
 157         }
 158
 159         return 0;
 160 }
 161 #endif