cpu/nios2/interrupts.c

   1 /*
   2  * (C) Copyright 2000-2002
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * (C) Copyright 2004, 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 <nios2.h>
  29 #include <nios2-io.h>
  30 #include <asm/io.h>
  31 #include <asm/ptrace.h>
  32 #include <common.h>
  33 #include <command.h>
  34 #include <watchdog.h>
  35 #ifdef CONFIG_STATUS_LED
  36 #include <status_led.h>
  37 #endif
  38
  39 #if defined(CFG_NIOS_TMRBASE) && !defined(CFG_NIOS_TMRIRQ)
  40 #error CFG_NIOS_TMRIRQ not defined (see documentation)
  41 #endif
  42
  43 /****************************************************************************/
  44
  45 struct  irq_action {
  46         interrupt_handler_t *handler;
  47         void *arg;
  48         int count;
  49 };
  50
  51 static struct irq_action vecs[32];
  52
  53 /*************************************************************************/
  54 volatile ulong timestamp = 0;
  55
  56 void reset_timer (void)
  57 {
  58         timestamp = 0;
  59 }
  60
  61 ulong get_timer (ulong base)
  62 {
  63         WATCHDOG_RESET ();
  64         return (timestamp - base);
  65 }
  66
  67 void set_timer (ulong t)
  68 {
  69         timestamp = t;
  70 }
  71
  72
  73 /* The board must handle this interrupt if a timer is not
  74  * provided.
  75  */
  76 #if defined(CFG_NIOS_TMRBASE)
  77 void tmr_isr (void *arg)
  78 {
  79         nios_timer_t *tmr = (nios_timer_t *)arg;
  80         /* Interrupt is cleared by writing anything to the
  81          * status register.
  82          */
  83         writel (&tmr->status, 0);
  84         timestamp += CFG_NIOS_TMRMS;
  85 #ifdef CONFIG_STATUS_LED
  86         status_led_tick(timestamp);
  87 #endif
  88 }
  89
  90 static void tmr_init (void)
  91 {
  92         nios_timer_t *tmr =(nios_timer_t *)CFG_NIOS_TMRBASE;
  93
  94         writel (&tmr->status, 0);
  95         writel (&tmr->control, 0);
  96         writel (&tmr->control, NIOS_TIMER_STOP);
  97
  98 #if defined(CFG_NIOS_TMRCNT)
  99         writel (&tmr->periodl, CFG_NIOS_TMRCNT & 0xffff);
 100         writel (&tmr->periodh, (CFG_NIOS_TMRCNT >> 16) & 0xffff);
 101 #endif
 102         writel (&tmr->control, NIOS_TIMER_ITO | NIOS_TIMER_CONT |
 103                           NIOS_TIMER_START );
 104         irq_install_handler (CFG_NIOS_TMRIRQ, tmr_isr, (void *)tmr);
 105 }
 106
 107 #endif /* CFG_NIOS_TMRBASE */
 108
 109 /*************************************************************************/
 110 int disable_interrupts (void)
 111 {
 112         int val = rdctl (CTL_STATUS);
 113         wrctl (CTL_STATUS, val & ~STATUS_IE);
 114         return (val & STATUS_IE);
 115 }
 116
 117 void enable_interrupts( void )
 118 {
 119         int val = rdctl (CTL_STATUS);
 120         wrctl (CTL_STATUS, val | STATUS_IE);
 121 }
 122
 123 void external_interrupt (struct pt_regs *regs)
 124 {
 125         unsigned irqs;
 126         struct irq_action *act;
 127
 128         /* Evaluate only irqs that are both enabled AND pending */
 129         irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING);
 130         act = vecs;
 131
 132         /* Assume (as does the Nios2 HAL) that bit 0 is highest
 133          * priority. NOTE: There is ALWAYS a handler assigned
 134          * (the default if no other).
 135          */
 136         while (irqs) {
 137                 if (irqs & 1) {
 138                         act->handler (act->arg);
 139                         act->count++;
 140                 }
 141                 irqs >>=1;
 142                 act++;
 143         }
 144 }
 145
 146 static void def_hdlr (void *arg)
 147 {
 148         unsigned irqs = rdctl (CTL_IENABLE);
 149
 150         /* Disable the individual interrupt -- with gratuitous
 151          * warning.
 152          */
 153         irqs &= ~(1 << (int)arg);
 154         wrctl (CTL_IENABLE, irqs);
 155         printf ("WARNING: Disabling unhandled interrupt: %d\n",
 156                         (int)arg);
 157 }
 158
 159 /*************************************************************************/
 160 void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg)
 161 {
 162
 163         int flag;
 164         struct irq_action *act;
 165         unsigned ena = rdctl (CTL_IENABLE);
 166
 167         if ((irq < 0) || (irq > 31))
 168                 return;
 169         act = &vecs[irq];
 170
 171         flag = disable_interrupts ();
 172         if (hdlr) {
 173                 act->handler = hdlr;
 174                 act->arg = arg;
 175                 ena |= (1 << irq);              /* enable */
 176         } else {
 177                 act->handler = def_hdlr;
 178                 act->arg = (void *)irq;
 179                 ena &= ~(1 << irq);             /* disable */
 180         }
 181         wrctl (CTL_IENABLE, ena);
 182         if (flag) enable_interrupts ();
 183 }
 184
 185
 186 int interrupt_init (void)
 187 {
 188         int i;
 189
 190         /* Assign the default handler to all */
 191         for (i = 0; i < 32; i++) {
 192                 vecs[i].handler = def_hdlr;
 193                 vecs[i].arg = (void *)i;
 194                 vecs[i].count = 0;
 195         }
 196
 197 #if defined(CFG_NIOS_TMRBASE)
 198         tmr_init ();
 199 #endif
 200
 201         enable_interrupts ();
 202         return (0);
 203 }
 204
 205
 206 /*************************************************************************/
 207 #if defined(CONFIG_CMD_IRQ)
 208 int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 209 {
 210         int i;
 211         struct irq_action *act = vecs;
 212
 213         printf ("\nInterrupt-Information:\n\n");
 214         printf ("Nr  Routine   Arg       Count\n");
 215         printf ("-----------------------------\n");
 216
 217         for (i=0; i<32; i++) {
 218                 if (act->handler != def_hdlr) {
 219                         printf ("%02d  %08lx  %08lx  %d\n",
 220                                 i,
 221                                 (ulong)act->handler,
 222                                 (ulong)act->arg,
 223                                 act->count);
 224                 }
 225                 act++;
 226         }
 227         printf ("\n");
 228
 229         return (0);
 230 }
 231 #endif