cpu/arm926ejs/interrupts.c

   1 /*
   2  * (C) Copyright 2003
   3  * Texas Instruments <www.ti.com>
   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  * (C) Copyright 2002
  14  * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
  15  *
  16  * See file CREDITS for list of people who contributed to this
  17  * project.
  18  *
  19  * This program is free software; you can redistribute it and/or
  20  * modify it under the terms of the GNU General Public License as
  21  * published by the Free Software Foundation; either version 2 of
  22  * the License, or (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program; if not, write to the Free Software
  31  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  32  * MA 02111-1307 USA
  33  */
  34
  35 #include <common.h>
  36 #include <arm925t.h>
  37
  38 #include <asm/proc-armv/ptrace.h>
  39
  40 extern void reset_cpu(ulong addr);
  41 #define TIMER_LOAD_VAL 0xffffffff
  42
  43 /* macro to read the 32 bit timer */
  44 #define READ_TIMER (*(volatile ulong *)(CFG_TIMERBASE+8))
  45
  46 #ifdef CONFIG_USE_IRQ
  47 /* enable IRQ interrupts */
  48 void enable_interrupts (void)
  49 {
  50         unsigned long temp;
  51         __asm__ __volatile__("mrs %0, cpsr\n"
  52                              "bic %0, %0, #0x80\n"
  53                              "msr cpsr_c, %0"
  54                              : "=r" (temp)
  55                              :
  56                              : "memory");
  57 }
  58
  59
  60 /*
  61  * disable IRQ/FIQ interrupts
  62  * returns true if interrupts had been enabled before we disabled them
  63  */
  64 int disable_interrupts (void)
  65 {
  66         unsigned long old,temp;
  67         __asm__ __volatile__("mrs %0, cpsr\n"
  68                              "orr %1, %0, #0xc0\n"
  69                              "msr cpsr_c, %1"
  70                              : "=r" (old), "=r" (temp)
  71                              :
  72                              : "memory");
  73         return (old & 0x80) == 0;
  74 }
  75 #else
  76 void enable_interrupts (void)
  77 {
  78         return;
  79 }
  80 int disable_interrupts (void)
  81 {
  82         return 0;
  83 }
  84 #endif
  85
  86
  87 void bad_mode (void)
  88 {
  89         panic ("Resetting CPU ...\n");
  90         reset_cpu (0);
  91 }
  92
  93 void show_regs (struct pt_regs *regs)
  94 {
  95         unsigned long flags;
  96         const char *processor_modes[] = {
  97         "USER_26",      "FIQ_26",       "IRQ_26",       "SVC_26",
  98         "UK4_26",       "UK5_26",       "UK6_26",       "UK7_26",
  99         "UK8_26",       "UK9_26",       "UK10_26",      "UK11_26",
 100         "UK12_26",      "UK13_26",      "UK14_26",      "UK15_26",
 101         "USER_32",      "FIQ_32",       "IRQ_32",       "SVC_32",
 102         "UK4_32",       "UK5_32",       "UK6_32",       "ABT_32",
 103         "UK8_32",       "UK9_32",       "UK10_32",      "UND_32",
 104         "UK12_32",      "UK13_32",      "UK14_32",      "SYS_32",
 105         };
 106
 107         flags = condition_codes (regs);
 108
 109         printf ("pc : [<%08lx>]    lr : [<%08lx>]\n"
 110                 "sp : %08lx  ip : %08lx  fp : %08lx\n",
 111                 instruction_pointer (regs),
 112                 regs->ARM_lr, regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
 113         printf ("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
 114                 regs->ARM_r10, regs->ARM_r9, regs->ARM_r8);
 115         printf ("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
 116                 regs->ARM_r7, regs->ARM_r6, regs->ARM_r5, regs->ARM_r4);
 117         printf ("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
 118                 regs->ARM_r3, regs->ARM_r2, regs->ARM_r1, regs->ARM_r0);
 119         printf ("Flags: %c%c%c%c",
 120                 flags & CC_N_BIT ? 'N' : 'n',
 121                 flags & CC_Z_BIT ? 'Z' : 'z',
 122                 flags & CC_C_BIT ? 'C' : 'c', flags & CC_V_BIT ? 'V' : 'v');
 123         printf ("  IRQs %s  FIQs %s  Mode %s%s\n",
 124                 interrupts_enabled (regs) ? "on" : "off",
 125                 fast_interrupts_enabled (regs) ? "on" : "off",
 126                 processor_modes[processor_mode (regs)],
 127                 thumb_mode (regs) ? " (T)" : "");
 128 }
 129
 130 void do_undefined_instruction (struct pt_regs *pt_regs)
 131 {
 132         printf ("undefined instruction\n");
 133         show_regs (pt_regs);
 134         bad_mode ();
 135 }
 136
 137 void do_software_interrupt (struct pt_regs *pt_regs)
 138 {
 139         printf ("software interrupt\n");
 140         show_regs (pt_regs);
 141         bad_mode ();
 142 }
 143
 144 void do_prefetch_abort (struct pt_regs *pt_regs)
 145 {
 146         printf ("prefetch abort\n");
 147         show_regs (pt_regs);
 148         bad_mode ();
 149 }
 150
 151 void do_data_abort (struct pt_regs *pt_regs)
 152 {
 153         printf ("data abort\n");
 154         show_regs (pt_regs);
 155         bad_mode ();
 156 }
 157
 158 void do_not_used (struct pt_regs *pt_regs)
 159 {
 160         printf ("not used\n");
 161         show_regs (pt_regs);
 162         bad_mode ();
 163 }
 164
 165 void do_fiq (struct pt_regs *pt_regs)
 166 {
 167         printf ("fast interrupt request\n");
 168         show_regs (pt_regs);
 169         bad_mode ();
 170 }
 171
 172 void do_irq (struct pt_regs *pt_regs)
 173 {
 174         printf ("interrupt request\n");
 175         show_regs (pt_regs);
 176         bad_mode ();
 177 }
 178
 179 static ulong timestamp;
 180 static ulong lastdec;
 181
 182 /* nothing really to do with interrupts, just starts up a counter. */
 183 int interrupt_init (void)
 184 {
 185         int32_t val;
 186
 187         /* Start the decrementer ticking down from 0xffffffff */
 188         *((int32_t *) (CFG_TIMERBASE + LOAD_TIM)) = TIMER_LOAD_VAL;
 189         val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | (CFG_PVT << MPUTIM_PTV_BIT);
 190         *((int32_t *) (CFG_TIMERBASE + CNTL_TIMER)) = val;
 191
 192         /* init the timestamp and lastdec value */
 193         reset_timer_masked();
 194
 195         return (0);
 196 }
 197
 198 /*
 199  * timer without interrupts
 200  */
 201
 202 void reset_timer (void)
 203 {
 204         reset_timer_masked ();
 205 }
 206
 207 ulong get_timer (ulong base)
 208 {
 209         return get_timer_masked () - base;
 210 }
 211
 212 void set_timer (ulong t)
 213 {
 214         timestamp = t;
 215 }
 216
 217 /* delay x useconds AND perserve advance timstamp value */
 218 void udelay (unsigned long usec)
 219 {
 220         ulong tmo, tmp;
 221
 222         if(usec >= 1000){               /* if "big" number, spread normalization to seconds */
 223                 tmo = usec / 1000;      /* start to normalize for usec to ticks per sec */
 224                 tmo *= CFG_HZ;          /* find number of "ticks" to wait to achieve target */
 225                 tmo /= 1000;            /* finish normalize. */
 226         }else{                          /* else small number, don't kill it prior to HZ multiply */
 227                 tmo = usec * CFG_HZ;
 228                 tmo /= (1000*1000);
 229         }
 230
 231         tmp = get_timer (0);            /* get current timestamp */
 232         if( (tmo + tmp) < tmp )         /* if setting this fordward will roll time stamp */
 233                 reset_timer_masked ();  /* reset "advancing" timestamp to 0, set lastdec value */
 234         else
 235                 tmo += tmp;             /* else, set advancing stamp wake up time */
 236
 237         while (get_timer_masked () < tmo)/* loop till event */
 238                 /*NOP*/;
 239 }
 240
 241 void reset_timer_masked (void)
 242 {
 243         /* reset time */
 244         lastdec = READ_TIMER;  /* capure current decrementer value time */
 245         timestamp = 0;         /* start "advancing" time stamp from 0 */
 246 }
 247
 248 ulong get_timer_masked (void)
 249 {
 250         ulong now = READ_TIMER;         /* current tick value */
 251
 252         if (lastdec >= now) {           /* normal mode (non roll) */
 253                 /* normal mode */
 254                 timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
 255         } else {                        /* we have overflow of the count down timer */
 256                 /* nts = ts + ld + (TLV - now)
 257                  * ts=old stamp, ld=time that passed before passing through -1
 258                  * (TLV-now) amount of time after passing though -1
 259                  * nts = new "advancing time stamp"...it could also roll and cause problems.
 260                  */
 261                 timestamp += lastdec + TIMER_LOAD_VAL - now;
 262         }
 263         lastdec = now;
 264
 265         return timestamp;
 266 }
 267
 268 /* waits specified delay value and resets timestamp */
 269 void udelay_masked (unsigned long usec)
 270 {
 271         ulong tmo, tmp;
 272
 273         if(usec >= 1000){               /* if "big" number, spread normalization to seconds */
 274                 tmo = usec / 1000;      /* start to normalize for usec to ticks per sec */
 275                 tmo *= CFG_HZ;          /* find number of "ticks" to wait to achieve target */
 276                 tmo /= 1000;            /* finish normalize. */
 277         }else{                          /* else small number, don't kill it prior to HZ multiply */
 278                 tmo = usec * CFG_HZ;
 279                 tmo /= (1000*1000);
 280         }
 281
 282         reset_timer_masked ();  /* set "advancing" timestamp to 0, set lastdec vaule */
 283
 284         while (get_timer_masked () < tmo) /* wait for time stamp to overtake tick number.*/
 285                 /*NOP*/;
 286 }
 287
 288 /*
 289  * This function is derived from PowerPC code (read timebase as long long).
 290  * On ARM it just returns the timer value.
 291  */
 292 unsigned long long get_ticks(void)
 293 {
 294         return get_timer(0);
 295 }
 296
 297 /*
 298  * This function is derived from PowerPC code (timebase clock frequency).
 299  * On ARM it returns the number of timer ticks per second.
 300  */
 301 ulong get_tbclk (void)
 302 {
 303         ulong tbclk;
 304
 305         tbclk = CFG_HZ;
 306         return tbclk;
 307 }