cpu/ixp/interrupts.c

   1 /*
   2  * (C) Copyright 2006
   3  * Stefan Roese, DENX Software Engineering, sr@denx.de.
   4  *
   5  * (C) Copyright 2002
   6  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   7  * Marius Groeger <mgroeger@sysgo.de>
   8  *
   9  * (C) Copyright 2002
  10  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
  11  * Alex Zuepke <azu@sysgo.de>
  12  *
  13  * See file CREDITS for list of people who contributed to this
  14  * project.
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation; either version 2 of
  19  * the License, or (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program; if not, write to the Free Software
  28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  29  * MA 02111-1307 USA
  30  */
  31
  32 #include <common.h>
  33 #include <asm/arch/ixp425.h>
  34
  35 #ifdef CONFIG_USE_IRQ
  36 /*
  37  * When interrupts are enabled, use timer 2 for time/delay generation...
  38  */
  39
  40 #define FREQ            66666666
  41 #define CLOCK_TICK_RATE (((FREQ / CFG_HZ & ~IXP425_OST_RELOAD_MASK) + 1) * CFG_HZ)
  42 #define LATCH           ((CLOCK_TICK_RATE + CFG_HZ/2) / CFG_HZ) /* For divider */
  43
  44 struct _irq_handler {
  45         void                *m_data;
  46         void (*m_func)( void *data);
  47 };
  48
  49 static struct _irq_handler IRQ_HANDLER[N_IRQS];
  50
  51 static volatile ulong timestamp;
  52
  53 /* enable IRQ/FIQ interrupts */
  54 void enable_interrupts(void)
  55 {
  56         unsigned long temp;
  57         __asm__ __volatile__("mrs %0, cpsr\n"
  58                              "bic %0, %0, #0x80\n"
  59                              "msr cpsr_c, %0"
  60                              : "=r" (temp)
  61                              :
  62                              : "memory");
  63 }
  64
  65 /*
  66  * disable IRQ/FIQ interrupts
  67  * returns true if interrupts had been enabled before we disabled them
  68  */
  69 int disable_interrupts(void)
  70 {
  71         unsigned long old,temp;
  72         __asm__ __volatile__("mrs %0, cpsr\n"
  73                              "orr %1, %0, #0x80\n"
  74                              "msr cpsr_c, %1"
  75                              : "=r" (old), "=r" (temp)
  76                              :
  77                              : "memory");
  78         return (old & 0x80) == 0;
  79 }
  80
  81 static void default_isr(void *data)
  82 {
  83         printf("default_isr():  called for IRQ %d, Interrupt Status=%x PR=%x\n",
  84                (int)data, *IXP425_ICIP, *IXP425_ICIH);
  85 }
  86
  87 static int next_irq(void)
  88 {
  89         return (((*IXP425_ICIH & 0x000000fc) >> 2) - 1);
  90 }
  91
  92 static void timer_isr(void *data)
  93 {
  94         unsigned int *pTime = (unsigned int *)data;
  95
  96         (*pTime)++;
  97
  98         /*
  99          * Reset IRQ source
 100          */
 101         *IXP425_OSST = IXP425_OSST_TIMER_2_PEND;
 102 }
 103
 104 ulong get_timer (ulong base)
 105 {
 106         return timestamp - base;
 107 }
 108
 109 void reset_timer (void)
 110 {
 111         timestamp = 0;
 112 }
 113
 114 #else /* #ifdef CONFIG_USE_IRQ */
 115 void enable_interrupts (void)
 116 {
 117         return;
 118 }
 119 int disable_interrupts (void)
 120 {
 121         return 0;
 122 }
 123 #endif /* #ifdef CONFIG_USE_IRQ */
 124
 125 void bad_mode (void)
 126 {
 127         panic ("Resetting CPU ...\n");
 128         reset_cpu (0);
 129 }
 130
 131 void show_regs (struct pt_regs *regs)
 132 {
 133         unsigned long flags;
 134         const char *processor_modes[] = {
 135         "USER_26",      "FIQ_26",       "IRQ_26",       "SVC_26",
 136         "UK4_26",       "UK5_26",       "UK6_26",       "UK7_26",
 137         "UK8_26",       "UK9_26",       "UK10_26",      "UK11_26",
 138         "UK12_26",      "UK13_26",      "UK14_26",      "UK15_26",
 139         "USER_32",      "FIQ_32",       "IRQ_32",       "SVC_32",
 140         "UK4_32",       "UK5_32",       "UK6_32",       "ABT_32",
 141         "UK8_32",       "UK9_32",       "UK10_32",      "UND_32",
 142         "UK12_32",      "UK13_32",      "UK14_32",      "SYS_32"
 143         };
 144
 145         flags = condition_codes (regs);
 146
 147         printf ("pc : [<%08lx>]    lr : [<%08lx>]\n"
 148                 "sp : %08lx  ip : %08lx  fp : %08lx\n",
 149                 instruction_pointer (regs),
 150                 regs->ARM_lr, regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
 151         printf ("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 152                 regs->ARM_r10, regs->ARM_r9, regs->ARM_r8);
 153         printf ("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 154                 regs->ARM_r7, regs->ARM_r6, regs->ARM_r5, regs->ARM_r4);
 155         printf ("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 156                 regs->ARM_r3, regs->ARM_r2, regs->ARM_r1, regs->ARM_r0);
 157         printf ("Flags: %c%c%c%c",
 158                 flags & CC_N_BIT ? 'N' : 'n',
 159                 flags & CC_Z_BIT ? 'Z' : 'z',
 160                 flags & CC_C_BIT ? 'C' : 'c', flags & CC_V_BIT ? 'V' : 'v');
 161         printf ("  IRQs %s  FIQs %s  Mode %s%s\n",
 162                 interrupts_enabled (regs) ? "on" : "off",
 163                 fast_interrupts_enabled (regs) ? "on" : "off",
 164                 processor_modes[processor_mode (regs)],
 165                 thumb_mode (regs) ? " (T)" : "");
 166 }
 167
 168 void do_undefined_instruction (struct pt_regs *pt_regs)
 169 {
 170         printf ("undefined instruction\n");
 171         show_regs (pt_regs);
 172         bad_mode ();
 173 }
 174
 175 void do_software_interrupt (struct pt_regs *pt_regs)
 176 {
 177         printf ("software interrupt\n");
 178         show_regs (pt_regs);
 179         bad_mode ();
 180 }
 181
 182 void do_prefetch_abort (struct pt_regs *pt_regs)
 183 {
 184         printf ("prefetch abort\n");
 185         show_regs (pt_regs);
 186         bad_mode ();
 187 }
 188
 189 void do_data_abort (struct pt_regs *pt_regs)
 190 {
 191         printf ("data abort\n");
 192         show_regs (pt_regs);
 193         bad_mode ();
 194 }
 195
 196 void do_not_used (struct pt_regs *pt_regs)
 197 {
 198         printf ("not used\n");
 199         show_regs (pt_regs);
 200         bad_mode ();
 201 }
 202
 203 void do_fiq (struct pt_regs *pt_regs)
 204 {
 205         printf ("fast interrupt request\n");
 206         show_regs (pt_regs);
 207         printf("IRQ=%08lx FIQ=%08lx\n", *IXP425_ICIH, *IXP425_ICFH);
 208 }
 209
 210 void do_irq (struct pt_regs *pt_regs)
 211 {
 212 #ifdef CONFIG_USE_IRQ
 213         int irq = next_irq();
 214
 215         IRQ_HANDLER[irq].m_func(IRQ_HANDLER[irq].m_data);
 216 #else
 217         printf ("interrupt request\n");
 218         show_regs (pt_regs);
 219         bad_mode ();
 220 #endif
 221 }
 222
 223 int interrupt_init (void)
 224 {
 225 #ifdef CONFIG_USE_IRQ
 226         int i;
 227
 228         /* install default interrupt handlers */
 229         for (i = 0; i < N_IRQS; i++) {
 230                 IRQ_HANDLER[i].m_data = (void *)i;
 231                 IRQ_HANDLER[i].m_func = default_isr;
 232         }
 233
 234         /* install interrupt handler for timer */
 235         IRQ_HANDLER[IXP425_TIMER_2_IRQ].m_data = (void *)&timestamp;
 236         IRQ_HANDLER[IXP425_TIMER_2_IRQ].m_func = timer_isr;
 237
 238         /* setup the Timer counter value */
 239         *IXP425_OSRT2 = (LATCH & ~IXP425_OST_RELOAD_MASK) | IXP425_OST_ENABLE;
 240
 241         /* configure interrupts for IRQ mode */
 242         *IXP425_ICLR = 0x00000000;
 243
 244         /* enable timer irq */
 245         *IXP425_ICMR = (1 << IXP425_TIMER_2_IRQ);
 246 #endif
 247
 248         return (0);
 249 }