cpu/nios/interrupts.c

   1 /*
   2  * (C) Copyright 2000-2002
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * (C) Copyright 2003, Psyent Corporation <www.psyent.com>
   6  * Scott McNutt <smcnutt@psyent.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
  28 #include <nios.h>
  29 #include <nios-io.h>
  30 #include <asm/ptrace.h>
  31 #include <common.h>
  32 #include <command.h>
  33
  34 /****************************************************************************/
  35
  36 struct  irq_action {
  37         interrupt_handler_t *handler;
  38         void *arg;
  39         int count;
  40 };
  41
  42 static struct irq_action irq_vecs[64];
  43
  44 /*************************************************************************/
  45 volatile ulong timestamp = 0;
  46
  47 void reset_timer (void)
  48 {
  49         timestamp = 0;
  50 }
  51
  52 ulong get_timer (ulong base)
  53 {
  54         return (timestamp - base);
  55 }
  56
  57 void set_timer (ulong t)
  58 {
  59         timestamp = t;
  60 }
  61
  62
  63 /* The board must handle this interrupt if a timer is not
  64  * provided.
  65  */
  66 #if defined(CFG_NIOS_TMRBASE)
  67 void timer_interrupt (struct pt_regs *regs)
  68 {
  69         /* Interrupt is cleared by writing anything to the
  70          * status register.
  71          */
  72         nios_timer_t *tmr = (nios_timer_t *)CFG_NIOS_TMRBASE;
  73         tmr->status = 0;
  74         timestamp += CFG_NIOS_TMRMS;
  75 }
  76 #endif
  77
  78 /*************************************************************************/
  79 int disable_interrupts (void)
  80 {
  81         int val = 0;
  82
  83         /* Writing anything to CLR_IE disables interrupts */
  84         val = rdctl (CTL_STATUS);
  85         wrctl (CTL_CLR_IE, 0);
  86         return (val & STATUS_IE);
  87 }
  88
  89 void enable_interrupts( void )
  90 {
  91         /* Writing anything SET_IE enables interrupts */
  92         wrctl (CTL_SET_IE, 0);
  93 }
  94
  95 void external_interrupt (struct pt_regs *regs)
  96 {
  97         unsigned vec;
  98
  99         vec = (regs->status & STATUS_IPRI) >> 9;        /* ipri */
 100
 101         irq_vecs[vec].count++;
 102         if (irq_vecs[vec].handler != NULL) {
 103                 (*irq_vecs[vec].handler)(irq_vecs[vec].arg);
 104         } else {
 105                 /* A sad side-effect of masking a bogus interrupt is
 106                  * that lower priority interrupts will also be disabled.
 107                  * This is probably not what we want ... so hang insted.
 108                  */
 109                 printf ("Unhandled interrupt: 0x%x\n", vec);
 110                 disable_interrupts ();
 111                 hang ();
 112         }
 113 }
 114
 115 /*************************************************************************/
 116 int interrupt_init (void)
 117 {
 118         int vec;
 119
 120 #if defined(CFG_NIOS_TMRBASE)
 121         nios_timer_t *tmr = (nios_timer_t *)CFG_NIOS_TMRBASE;
 122
 123         tmr->control &= ~NIOS_TIMER_ITO;
 124         tmr->control |= NIOS_TIMER_STOP;
 125 #endif
 126
 127         for (vec=0; vec<64; vec++ ) {
 128                 irq_vecs[vec].handler = NULL;
 129                 irq_vecs[vec].arg = NULL;
 130                 irq_vecs[vec].count = 0;
 131         }
 132
 133         /* Need timus interruptus -- start the lopri timer */
 134 #if defined(CFG_NIOS_TMRBASE)
 135         tmr->control |= ( NIOS_TIMER_ITO |
 136                           NIOS_TIMER_CONT |
 137                           NIOS_TIMER_START );
 138         ipri (CFG_NIOS_TMRIRQ + 1);
 139 #endif
 140         enable_interrupts ();
 141         return (0);
 142 }
 143
 144 void irq_install_handler (int vec, interrupt_handler_t *handler, void *arg)
 145 {
 146         struct irq_action *irqa = irq_vecs;
 147         int   i = vec;
 148         int flag;
 149
 150         if (irqa[i].handler != NULL) {
 151                 printf ("Interrupt vector %d: handler 0x%x "
 152                         "replacing 0x%x\n",
 153                         vec, (uint)handler, (uint)irqa[i].handler);
 154         }
 155
 156         flag = disable_interrupts ();
 157         irqa[i].handler = handler;
 158         irqa[i].arg = arg;
 159         if (flag )
 160                 enable_interrupts ();
 161 }
 162
 163 /*************************************************************************/
 164 #if (CONFIG_COMMANDS & CFG_CMD_IRQ)
 165 int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 166 {
 167         int vec;
 168
 169         printf ("\nInterrupt-Information:\n");
 170         printf ("Nr  Routine   Arg       CouIt's ok to cnt\n");
 171
 172         for (vec=0; vec<64; vec++) {
 173                 if (irq_vecs[vec].handler != NULL) {
 174                         printf ("%02d  %08lx  %08lx  %d\n",
 175                                 vec,
 176                                 (ulong)irq_vecs[vec].handler<<1,
 177                                 (ulong)irq_vecs[vec].arg,
 178                                 irq_vecs[vec].count);
 179                 }
 180         }
 181
 182         return (0);
 183 }
 184 #endif  /* CONFIG_COMMANDS & CFG_CMD_IRQ */