git.rot13.org Git - simavr/blob - simavr/sim/sim_irq.c

   1 /*
   2         sim_irq.c
   3
   4         Copyright 2008, 2009 Michel Pollet <buserror@gmail.com>
   5
   6         This file is part of simavr.
   7
   8         simavr is free software: you can redistribute it and/or modify
   9         it under the terms of the GNU General Public License as published by
  10         the Free Software Foundation, either version 3 of the License, or
  11         (at your option) any later version.
  12
  13         simavr is distributed in the hope that it will be useful,
  14         but WITHOUT ANY WARRANTY; without even the implied warranty of
  15         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16         GNU General Public License for more details.
  17
  18         You should have received a copy of the GNU General Public License
  19         along with simavr.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include "sim_irq.h"
  26
  27 // internal structure for a hook, never seen by the notify procs
  28 typedef struct avr_irq_hook_t {
  29         struct avr_irq_hook_t * next;
  30         int busy;       // prevent reentrance of callbacks
  31
  32         struct avr_irq_t * chain;       // raise the IRQ on this too - optional if "notify" is on
  33         avr_irq_notify_t notify;        // called when IRQ is raised - optional if "chain" is on
  34         void * param;                           // "notify" parameter
  35 } avr_irq_hook_t;
  36
  37 static void
  38 _avr_irq_pool_add(
  39                 avr_irq_pool_t * pool,
  40                 avr_irq_t * irq)
  41 {
  42         if ((pool->count & 0xf) == 0) {
  43                 pool->irq = (avr_irq_t**)realloc(pool->irq,
  44                                 (pool->count + 16) * sizeof(avr_irq_t *));
  45         }
  46         pool->irq[pool->count++] = irq;
  47         irq->pool = pool;
  48 }
  49
  50 static void
  51 _avr_irq_pool_remove(
  52                 avr_irq_pool_t * pool,
  53                 avr_irq_t * irq)
  54 {
  55         for (int i = 0; i < pool->count; i++)
  56                 if (pool->irq[i] == irq) {
  57                         pool->irq[i] = 0;
  58                         return;
  59                 }
  60 }
  61
  62 void
  63 avr_init_irq(
  64                 avr_irq_pool_t * pool,
  65                 avr_irq_t * irq,
  66                 uint32_t base,
  67                 uint32_t count,
  68                 const char ** names /* optional */)
  69 {
  70         memset(irq, 0, sizeof(avr_irq_t) * count);
  71
  72         for (int i = 0; i < count; i++) {
  73                 irq[i].irq = base + i;
  74                 if (pool)
  75                         _avr_irq_pool_add(pool, &irq[i]);
  76                 if (names && names[i])
  77                         irq[i].name = strdup(names[i]);
  78         }
  79 }
  80
  81 avr_irq_t *
  82 avr_alloc_irq(
  83                 avr_irq_pool_t * pool,
  84                 uint32_t base,
  85                 uint32_t count,
  86                 const char ** names /* optional */)
  87 {
  88         avr_irq_t * irq = (avr_irq_t*)malloc(sizeof(avr_irq_t) * count);
  89         avr_init_irq(pool, irq, base, count, names);
  90         for (int i = 0; i < count; i++)
  91                 irq[i].flags |= IRQ_FLAG_ALLOC;
  92         return irq;
  93 }
  94
  95 static avr_irq_hook_t *
  96 _avr_alloc_irq_hook(
  97                 avr_irq_t * irq)
  98 {
  99         avr_irq_hook_t *hook = malloc(sizeof(avr_irq_hook_t));
 100         memset(hook, 0, sizeof(avr_irq_hook_t));
 101         hook->next = irq->hook;
 102         irq->hook = hook;
 103         return hook;
 104 }
 105
 106 void
 107 avr_free_irq(
 108                 avr_irq_t * irq,
 109                 uint32_t count)
 110 {
 111         if (!irq || !count)
 112                 return;
 113         for (int i = 0; i < count; i++) {
 114                 avr_irq_t * iq = irq + i;
 115                 if (iq->pool)
 116                         _avr_irq_pool_remove(iq->pool, iq);
 117                 if (iq->name)
 118                         free((char*)iq->name);
 119                 iq->name = NULL;
 120                 // purge hooks
 121                 avr_irq_hook_t *hook = iq->hook;
 122                 while (hook) {
 123                         avr_irq_hook_t * next = hook->next;
 124                         free(hook);
 125                         hook = next;
 126                 }
 127                 iq->hook = NULL;
 128         }
 129         // if that irq list was allocated by us, free it
 130         if (irq->flags & IRQ_FLAG_ALLOC)
 131                 free(irq);
 132 }
 133
 134 void
 135 avr_irq_register_notify(
 136                 avr_irq_t * irq,
 137                 avr_irq_notify_t notify,
 138                 void * param)
 139 {
 140         if (!irq || !notify)
 141                 return;
 142
 143         avr_irq_hook_t *hook = irq->hook;
 144         while (hook) {
 145                 if (hook->notify == notify && hook->param == param)
 146                         return; // already there
 147                 hook = hook->next;
 148         }
 149         hook = _avr_alloc_irq_hook(irq);
 150         hook->notify = notify;
 151         hook->param = param;
 152 }
 153
 154 void
 155 avr_irq_unregister_notify(
 156                 avr_irq_t * irq,
 157                 avr_irq_notify_t notify,
 158                 void * param)
 159 {
 160         avr_irq_hook_t *hook, *prev;
 161         if (!irq || !notify)
 162                 return;
 163
 164         hook = irq->hook;
 165         prev = NULL;
 166         while (hook) {
 167                 if (hook->notify == notify && hook->param == param)
 168                 {
 169                         if ( prev )
 170                                 prev->next = hook->next;
 171                         else
 172                                 irq->hook = hook->next;
 173                         free(hook);
 174                         return;
 175                 }
 176                 prev = hook;
 177                 hook = hook->next;
 178         }
 179 }
 180
 181 void
 182 avr_raise_irq(
 183                 avr_irq_t * irq,
 184                 uint32_t value)
 185 {
 186         if (!irq)
 187                 return ;
 188         uint32_t output = (irq->flags & IRQ_FLAG_NOT) ? !value : value;
 189         if (irq->value == output && (irq->flags & IRQ_FLAG_FILTERED))
 190                 return;
 191         avr_irq_hook_t *hook = irq->hook;
 192         while (hook) {
 193                 avr_irq_hook_t * next = hook->next;
 194                         // prevents reentrance / endless calling loops
 195                 if (hook->busy == 0) {
 196                         hook->busy++;
 197                         if (hook->notify)
 198                                 hook->notify(irq, output,  hook->param);
 199                         if (hook->chain)
 200                                 avr_raise_irq(hook->chain, output);
 201                         hook->busy--;
 202                 }
 203                 hook = next;
 204         }
 205         // the value is set after the callbacks are called, so the callbacks
 206         // can themselves compare for old/new values between their parameter
 207         // they are passed (new value) and the previous irq->value
 208         irq->value = output;
 209 }
 210
 211 void
 212 avr_connect_irq(
 213                 avr_irq_t * src,
 214                 avr_irq_t * dst)
 215 {
 216         if (!src || !dst || src == dst) {
 217                 printf("avr_connect_irq invalid irq %p/%p", src, dst);
 218                 return;
 219         }
 220         avr_irq_hook_t *hook = src->hook;
 221         while (hook) {
 222                 if (hook->chain == dst)
 223                         return; // already there
 224                 hook = hook->next;
 225         }
 226         hook = _avr_alloc_irq_hook(src);
 227         hook->chain = dst;
 228 }
 229
 230 void
 231 avr_unconnect_irq(
 232                 avr_irq_t * src,
 233                 avr_irq_t * dst)
 234 {
 235         avr_irq_hook_t *hook, *prev;
 236
 237         if (!src || !dst || src == dst) {
 238                 printf("error: avr_connect_irq invalid irq %p/%p", src, dst); fflush(stdout);
 239                 return;
 240         }
 241         hook = src->hook;
 242         prev = NULL;
 243         while (hook) {
 244                 if (hook->chain == dst)
 245                 {
 246                         if ( prev )
 247                                 prev->next = hook->next;
 248                         else
 249                                 src->hook = hook->next;
 250                         free(hook);
 251                         return;
 252                 }
 253                 prev = hook;
 254                 hook = hook->next;
 255         }
 256 }