arch/m68k/mac/via.c

   1 /*
   2  *      6522 Versatile Interface Adapter (VIA)
   3  *
   4  *      There are two of these on the Mac II. Some IRQs are vectored
   5  *      via them as are assorted bits and bobs - eg RTC, ADB.
   6  *
   7  * CSA: Motorola seems to have removed documentation on the 6522 from
   8  * their web site; try
   9  *     http://nerini.drf.com/vectrex/other/text/chips/6522/
  10  *     http://www.zymurgy.net/classic/vic20/vicdet1.htm
  11  * and
  12  *     http://193.23.168.87/mikro_laborversuche/via_iobaustein/via6522_1.html
  13  * for info.  A full-text web search on 6522 AND VIA will probably also
  14  * net some usefulness. <cananian@alumni.princeton.edu> 20apr1999
  15  *
  16  * Additional data is here (the SY6522 was used in the Mac II etc):
  17  *     http://www.6502.org/documents/datasheets/synertek/synertek_sy6522.pdf
  18  *     http://www.6502.org/documents/datasheets/synertek/synertek_sy6522_programming_reference.pdf
  19  *
  20  * PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
  21  * by Erik Vogan and adapted to Linux by Joshua M. Thompson (funaho@jurai.org)
  22  *
  23  */
  24
  25 #include <linux/types.h>
  26 #include <linux/kernel.h>
  27 #include <linux/mm.h>
  28 #include <linux/delay.h>
  29 #include <linux/init.h>
  30 #include <linux/ide.h>
  31 #include <linux/module.h>
  32
  33 #include <asm/bootinfo.h>
  34 #include <asm/macintosh.h>
  35 #include <asm/macints.h>
  36 #include <asm/machw.h>
  37 #include <asm/mac_via.h>
  38 #include <asm/mac_psc.h>
  39
  40 volatile __u8 *via1, *via2;
  41 #if 0
  42 /* See note in mac_via.h about how this is possibly not useful */
  43 volatile long *via_memory_bogon=(long *)&via_memory_bogon;
  44 #endif
  45 int rbv_present;
  46 int via_alt_mapping;
  47 EXPORT_SYMBOL(via_alt_mapping);
  48 __u8 rbv_clear;
  49
  50 /*
  51  * Globals for accessing the VIA chip registers without having to
  52  * check if we're hitting a real VIA or an RBV. Normally you could
  53  * just hit the combined register (ie, vIER|rIER) but that seems to
  54  * break on AV Macs...probably because they actually decode more than
  55  * eight address bits. Why can't Apple engineers at least be
  56  * _consistently_ lazy?                          - 1999-05-21 (jmt)
  57  */
  58
  59 static int gIER,gIFR,gBufA,gBufB;
  60
  61 /*
  62  * Timer defs.
  63  */
  64
  65 #define TICK_SIZE               10000
  66 #define MAC_CLOCK_TICK          (783300/HZ)             /* ticks per HZ */
  67 #define MAC_CLOCK_LOW           (MAC_CLOCK_TICK&0xFF)
  68 #define MAC_CLOCK_HIGH          (MAC_CLOCK_TICK>>8)
  69
  70 /* To disable a NuBus slot on Quadras we make the slot IRQ lines outputs, set
  71  * high. On RBV we just use the slot interrupt enable register. On Macs with
  72  * genuine VIA chips we must use nubus_disabled to keep track of disabled slot
  73  * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
  74  * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
  75  * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
  76  * because closing one of those drivers can mask all of the NuBus interrupts.
  77  * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
  78  * possible to get interrupts from cards that MacOS or the ROM has configured
  79  * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
  80  * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
  81  */
  82 static u8 nubus_disabled;
  83
  84 void via_debug_dump(void);
  85 irqreturn_t via1_irq(int, void *);
  86 irqreturn_t via2_irq(int, void *);
  87 irqreturn_t via_nubus_irq(int, void *);
  88 void via_irq_enable(int irq);
  89 void via_irq_disable(int irq);
  90 void via_irq_clear(int irq);
  91
  92 extern irqreturn_t mac_scc_dispatch(int, void *);
  93 extern int oss_present;
  94
  95 /*
  96  * Initialize the VIAs
  97  *
  98  * First we figure out where they actually _are_ as well as what type of
  99  * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
 100  * Then we pretty much clear them out and disable all IRQ sources.
 101  *
 102  * Note: the OSS is actually "detected" here and not in oss_init(). It just
 103  *       seems more logical to do it here since via_init() needs to know
 104  *       these things anyways.
 105  */
 106
 107 void __init via_init(void)
 108 {
 109         switch(macintosh_config->via_type) {
 110
 111                 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
 112
 113                 case MAC_VIA_IIci:
 114                         via1 = (void *) VIA1_BASE;
 115                         if (macintosh_config->ident == MAC_MODEL_IIFX) {
 116                                 via2 = NULL;
 117                                 rbv_present = 0;
 118                                 oss_present = 1;
 119                         } else {
 120                                 via2 = (void *) RBV_BASE;
 121                                 rbv_present = 1;
 122                                 oss_present = 0;
 123                         }
 124                         if (macintosh_config->ident == MAC_MODEL_LCIII) {
 125                                 rbv_clear = 0x00;
 126                         } else {
 127                                 /* on most RBVs (& unlike the VIAs), you   */
 128                                 /* need to set bit 7 when you write to IFR */
 129                                 /* in order for your clear to occur.       */
 130                                 rbv_clear = 0x80;
 131                         }
 132                         gIER = rIER;
 133                         gIFR = rIFR;
 134                         gBufA = rSIFR;
 135                         gBufB = rBufB;
 136                         break;
 137
 138                 /* Quadra and early MacIIs agree on the VIA locations */
 139
 140                 case MAC_VIA_QUADRA:
 141                 case MAC_VIA_II:
 142                         via1 = (void *) VIA1_BASE;
 143                         via2 = (void *) VIA2_BASE;
 144                         rbv_present = 0;
 145                         oss_present = 0;
 146                         rbv_clear = 0x00;
 147                         gIER = vIER;
 148                         gIFR = vIFR;
 149                         gBufA = vBufA;
 150                         gBufB = vBufB;
 151                         break;
 152                 default:
 153                         panic("UNKNOWN VIA TYPE");
 154         }
 155
 156         printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
 157
 158         printk(KERN_INFO "VIA2 at %p is ", via2);
 159         if (rbv_present) {
 160                 printk("an RBV\n");
 161         } else if (oss_present) {
 162                 printk("an OSS\n");
 163         } else {
 164                 printk("a 6522 or clone\n");
 165         }
 166
 167 #ifdef DEBUG_VIA
 168         via_debug_dump();
 169 #endif
 170
 171         /*
 172          * Shut down all IRQ sources, reset the timers, and
 173          * kill the timer latch on VIA1.
 174          */
 175
 176         via1[vIER] = 0x7F;
 177         via1[vIFR] = 0x7F;
 178         via1[vT1LL] = 0;
 179         via1[vT1LH] = 0;
 180         via1[vT1CL] = 0;
 181         via1[vT1CH] = 0;
 182         via1[vT2CL] = 0;
 183         via1[vT2CH] = 0;
 184         via1[vACR] &= 0x3F;
 185         via1[vACR] &= ~0x03; /* disable port A & B latches */
 186
 187         /*
 188          * SE/30: disable video IRQ
 189          * XXX: testing for SE/30 VBL
 190          */
 191
 192         if (macintosh_config->ident == MAC_MODEL_SE30) {
 193                 via1[vDirB] |= 0x40;
 194                 via1[vBufB] |= 0x40;
 195         }
 196
 197         /*
 198          * Set the RTC bits to a known state: all lines to outputs and
 199          * RTC disabled (yes that's 0 to enable and 1 to disable).
 200          */
 201
 202         via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
 203         via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
 204
 205         /* Everything below this point is VIA2/RBV only... */
 206
 207         if (oss_present) return;
 208
 209 #if 1
 210         /* Some machines support an alternate IRQ mapping that spreads  */
 211         /* Ethernet and Sound out to their own autolevel IRQs and moves */
 212         /* VIA1 to level 6. A/UX uses this mapping and we do too.  Note */
 213         /* that the IIfx emulates this alternate mapping using the OSS. */
 214
 215         switch(macintosh_config->ident) {
 216                 case MAC_MODEL_P475:
 217                 case MAC_MODEL_P475F:
 218                 case MAC_MODEL_P575:
 219                 case MAC_MODEL_Q605:
 220                 case MAC_MODEL_Q605_ACC:
 221                 case MAC_MODEL_C610:
 222                 case MAC_MODEL_Q610:
 223                 case MAC_MODEL_Q630:
 224                 case MAC_MODEL_C650:
 225                 case MAC_MODEL_Q650:
 226                 case MAC_MODEL_Q700:
 227                 case MAC_MODEL_Q800:
 228                 case MAC_MODEL_Q900:
 229                 case MAC_MODEL_Q950:
 230                         via_alt_mapping = 1;
 231                         via1[vDirB] |= 0x40;
 232                         via1[vBufB] &= ~0x40;
 233                         break;
 234                 default:
 235                         via_alt_mapping = 0;
 236                         break;
 237         }
 238 #else
 239         via_alt_mapping = 0;
 240 #endif
 241
 242         /*
 243          * Now initialize VIA2. For RBV we just kill all interrupts;
 244          * for a regular VIA we also reset the timers and stuff.
 245          */
 246
 247         via2[gIER] = 0x7F;
 248         via2[gIFR] = 0x7F | rbv_clear;
 249         if (!rbv_present) {
 250                 via2[vT1LL] = 0;
 251                 via2[vT1LH] = 0;
 252                 via2[vT1CL] = 0;
 253                 via2[vT1CH] = 0;
 254                 via2[vT2CL] = 0;
 255                 via2[vT2CH] = 0;
 256                 via2[vACR] &= 0x3F;
 257                 via2[vACR] &= ~0x03; /* disable port A & B latches */
 258         }
 259
 260         /*
 261          * Set vPCR for SCSI interrupts (but not on RBV)
 262          */
 263         if (!rbv_present) {
 264                 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
 265                         /* CB2 (IRQ) indep. input, positive edge */
 266                         /* CA2 (DRQ) indep. input, positive edge */
 267                         via2[vPCR] = 0x66;
 268                 } else {
 269                         /* CB2 (IRQ) indep. input, negative edge */
 270                         /* CA2 (DRQ) indep. input, negative edge */
 271                         via2[vPCR] = 0x22;
 272                 }
 273         }
 274 }
 275
 276 /*
 277  * Start the 100 Hz clock
 278  */
 279
 280 void __init via_init_clock(irq_handler_t func)
 281 {
 282         via1[vACR] |= 0x40;
 283         via1[vT1LL] = MAC_CLOCK_LOW;
 284         via1[vT1LH] = MAC_CLOCK_HIGH;
 285         via1[vT1CL] = MAC_CLOCK_LOW;
 286         via1[vT1CH] = MAC_CLOCK_HIGH;
 287
 288         request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
 289 }
 290
 291 /*
 292  * Register the interrupt dispatchers for VIA or RBV machines only.
 293  */
 294
 295 void __init via_register_interrupts(void)
 296 {
 297         if (via_alt_mapping) {
 298                 request_irq(IRQ_AUTO_1, via1_irq,
 299                                 IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
 300                                 (void *) via1);
 301                 request_irq(IRQ_AUTO_6, via1_irq,
 302                                 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
 303                                 (void *) via1);
 304         } else {
 305                 request_irq(IRQ_AUTO_1, via1_irq,
 306                                 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
 307                                 (void *) via1);
 308         }
 309         request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 310                         "via2", (void *) via2);
 311         if (!psc_present) {
 312                 request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
 313                                 "scc", mac_scc_dispatch);
 314         }
 315         request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 316                         "nubus", (void *) via2);
 317 }
 318
 319 /*
 320  * Debugging dump, used in various places to see what's going on.
 321  */
 322
 323 void via_debug_dump(void)
 324 {
 325         printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 326                 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
 327         printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 328                 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
 329         if (oss_present) {
 330                 printk(KERN_DEBUG "VIA2: <OSS>\n");
 331         } else if (rbv_present) {
 332                 printk(KERN_DEBUG "VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
 333                         (uint) via2[rIFR], (uint) via2[rIER]);
 334                 printk(KERN_DEBUG "      SIFR = 0x%02X SIER = 0x%02X\n",
 335                         (uint) via2[rSIFR], (uint) via2[rSIER]);
 336         } else {
 337                 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 338                         (uint) via2[vDirA], (uint) via2[vDirB],
 339                         (uint) via2[vACR]);
 340                 printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 341                         (uint) via2[vPCR],
 342                         (uint) via2[vIFR], (uint) via2[vIER]);
 343         }
 344 }
 345
 346 /*
 347  * This is always executed with interrupts disabled.
 348  *
 349  * TBI: get time offset between scheduling timer ticks
 350  */
 351
 352 unsigned long mac_gettimeoffset (void)
 353 {
 354         unsigned long ticks, offset = 0;
 355
 356         /* read VIA1 timer 2 current value */
 357         ticks = via1[vT1CL] | (via1[vT1CH] << 8);
 358         /* The probability of underflow is less than 2% */
 359         if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
 360                 /* Check for pending timer interrupt in VIA1 IFR */
 361                 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
 362
 363         ticks = MAC_CLOCK_TICK - ticks;
 364         ticks = ticks * 10000L / MAC_CLOCK_TICK;
 365
 366         return ticks + offset;
 367 }
 368
 369 /*
 370  * Flush the L2 cache on Macs that have it by flipping
 371  * the system into 24-bit mode for an instant.
 372  */
 373
 374 void via_flush_cache(void)
 375 {
 376         via2[gBufB] &= ~VIA2B_vMode32;
 377         via2[gBufB] |= VIA2B_vMode32;
 378 }
 379
 380 /*
 381  * Return the status of the L2 cache on a IIci
 382  */
 383
 384 int via_get_cache_disable(void)
 385 {
 386         /* Safeguard against being called accidentally */
 387         if (!via2) {
 388                 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
 389                 return 1;
 390         }
 391
 392         return (int) via2[gBufB] & VIA2B_vCDis;
 393 }
 394
 395 /*
 396  * Initialize VIA2 for Nubus access
 397  */
 398
 399 void __init via_nubus_init(void)
 400 {
 401         /* unlock nubus transactions */
 402
 403         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 404             (macintosh_config->adb_type != MAC_ADB_PB2)) {
 405                 /* set the line to be an output on non-RBV machines */
 406                 if (!rbv_present)
 407                         via2[vDirB] |= 0x02;
 408
 409                 /* this seems to be an ADB bit on PMU machines */
 410                 /* according to MkLinux.  -- jmt               */
 411                 via2[gBufB] |= 0x02;
 412         }
 413
 414         /* Disable all the slot interrupts (where possible). */
 415
 416         switch (macintosh_config->via_type) {
 417         case MAC_VIA_II:
 418                 /* Just make the port A lines inputs. */
 419                 switch(macintosh_config->ident) {
 420                 case MAC_MODEL_II:
 421                 case MAC_MODEL_IIX:
 422                 case MAC_MODEL_IICX:
 423                 case MAC_MODEL_SE30:
 424                         /* The top two bits are RAM size outputs. */
 425                         via2[vDirA] &= 0xC0;
 426                         break;
 427                 default:
 428                         via2[vDirA] &= 0x80;
 429                 }
 430                 break;
 431         case MAC_VIA_IIci:
 432                 /* RBV. Disable all the slot interrupts. SIER works like IER. */
 433                 via2[rSIER] = 0x7F;
 434                 break;
 435         case MAC_VIA_QUADRA:
 436                 /* Disable the inactive slot interrupts by making those lines outputs. */
 437                 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 438                     (macintosh_config->adb_type != MAC_ADB_PB2)) {
 439                         via2[vBufA] |= 0x7F;
 440                         via2[vDirA] |= 0x7F;
 441                 }
 442                 break;
 443         }
 444 }
 445
 446 /*
 447  * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
 448  * via6522.c :-), disable/pending masks added.
 449  */
 450
 451 irqreturn_t via1_irq(int irq, void *dev_id)
 452 {
 453         int irq_num;
 454         unsigned char irq_bit, events;
 455
 456         events = via1[vIFR] & via1[vIER] & 0x7F;
 457         if (!events)
 458                 return IRQ_NONE;
 459
 460         irq_num = VIA1_SOURCE_BASE;
 461         irq_bit = 1;
 462         do {
 463                 if (events & irq_bit) {
 464                         via1[vIFR] = irq_bit;
 465                         m68k_handle_int(irq_num);
 466                 }
 467                 ++irq_num;
 468                 irq_bit <<= 1;
 469         } while (events >= irq_bit);
 470
 471 #if 0 /* freakin' pmu is doing weird stuff */
 472         if (!oss_present) {
 473                 /* This (still) seems to be necessary to get IDE
 474                    working.  However, if you enable VBL interrupts,
 475                    you're screwed... */
 476                 /* FIXME: should we check the SLOTIRQ bit before
 477                    pulling this stunt? */
 478                 /* No, it won't be set. that's why we're doing this. */
 479                 via_irq_disable(IRQ_MAC_NUBUS);
 480                 via_irq_clear(IRQ_MAC_NUBUS);
 481                 m68k_handle_int(IRQ_MAC_NUBUS);
 482                 via_irq_enable(IRQ_MAC_NUBUS);
 483         }
 484 #endif
 485         return IRQ_HANDLED;
 486 }
 487
 488 irqreturn_t via2_irq(int irq, void *dev_id)
 489 {
 490         int irq_num;
 491         unsigned char irq_bit, events;
 492
 493         events = via2[gIFR] & via2[gIER] & 0x7F;
 494         if (!events)
 495                 return IRQ_NONE;
 496
 497         irq_num = VIA2_SOURCE_BASE;
 498         irq_bit = 1;
 499         do {
 500                 if (events & irq_bit) {
 501                         via2[gIFR] = irq_bit | rbv_clear;
 502                         m68k_handle_int(irq_num);
 503                 }
 504                 ++irq_num;
 505                 irq_bit <<= 1;
 506         } while (events >= irq_bit);
 507         return IRQ_HANDLED;
 508 }
 509
 510 /*
 511  * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
 512  * VIA2 dispatcher as a fast interrupt handler.
 513  */
 514
 515 irqreturn_t via_nubus_irq(int irq, void *dev_id)
 516 {
 517         int slot_irq;
 518         unsigned char slot_bit, events;
 519
 520         events = ~via2[gBufA] & 0x7F;
 521         if (rbv_present)
 522                 events &= via2[rSIER];
 523         else
 524                 events &= ~via2[vDirA];
 525         if (!events)
 526                 return IRQ_NONE;
 527
 528         do {
 529                 slot_irq = IRQ_NUBUS_F;
 530                 slot_bit = 0x40;
 531                 do {
 532                         if (events & slot_bit) {
 533                                 events &= ~slot_bit;
 534                                 m68k_handle_int(slot_irq);
 535                         }
 536                         --slot_irq;
 537                         slot_bit >>= 1;
 538                 } while (events);
 539
 540                 /* clear the CA1 interrupt and make certain there's no more. */
 541                 via2[gIFR] = 0x02 | rbv_clear;
 542                 events = ~via2[gBufA] & 0x7F;
 543                 if (rbv_present)
 544                         events &= via2[rSIER];
 545                 else
 546                         events &= ~via2[vDirA];
 547         } while (events);
 548         return IRQ_HANDLED;
 549 }
 550
 551 void via_irq_enable(int irq) {
 552         int irq_src     = IRQ_SRC(irq);
 553         int irq_idx     = IRQ_IDX(irq);
 554
 555 #ifdef DEBUG_IRQUSE
 556         printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
 557 #endif
 558
 559         if (irq_src == 1) {
 560                 via1[vIER] = IER_SET_BIT(irq_idx);
 561         } else if (irq_src == 2) {
 562                 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
 563                         via2[gIER] = IER_SET_BIT(irq_idx);
 564         } else if (irq_src == 7) {
 565                 switch (macintosh_config->via_type) {
 566                 case MAC_VIA_II:
 567                         nubus_disabled &= ~(1 << irq_idx);
 568                         /* Enable the CA1 interrupt when no slot is disabled. */
 569                         if (!nubus_disabled)
 570                                 via2[gIER] = IER_SET_BIT(1);
 571                         break;
 572                 case MAC_VIA_IIci:
 573                         /* On RBV, enable the slot interrupt.
 574                          * SIER works like IER.
 575                          */
 576                         via2[rSIER] = IER_SET_BIT(irq_idx);
 577                         break;
 578                 case MAC_VIA_QUADRA:
 579                         /* Make the port A line an input to enable the slot irq.
 580                          * But not on PowerBooks, that's ADB.
 581                          */
 582                         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 583                             (macintosh_config->adb_type != MAC_ADB_PB2))
 584                                 via2[vDirA] &= ~(1 << irq_idx);
 585                         break;
 586                 }
 587         }
 588 }
 589
 590 void via_irq_disable(int irq) {
 591         int irq_src     = IRQ_SRC(irq);
 592         int irq_idx     = IRQ_IDX(irq);
 593
 594 #ifdef DEBUG_IRQUSE
 595         printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
 596 #endif
 597
 598         if (irq_src == 1) {
 599                 via1[vIER] = IER_CLR_BIT(irq_idx);
 600         } else if (irq_src == 2) {
 601                 via2[gIER] = IER_CLR_BIT(irq_idx);
 602         } else if (irq_src == 7) {
 603                 switch (macintosh_config->via_type) {
 604                 case MAC_VIA_II:
 605                         nubus_disabled |= 1 << irq_idx;
 606                         if (nubus_disabled)
 607                                 via2[gIER] = IER_CLR_BIT(1);
 608                         break;
 609                 case MAC_VIA_IIci:
 610                         via2[rSIER] = IER_CLR_BIT(irq_idx);
 611                         break;
 612                 case MAC_VIA_QUADRA:
 613                         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 614                             (macintosh_config->adb_type != MAC_ADB_PB2))
 615                                 via2[vDirA] |= 1 << irq_idx;
 616                         break;
 617                 }
 618         }
 619 }
 620
 621 void via_irq_clear(int irq) {
 622         int irq_src     = IRQ_SRC(irq);
 623         int irq_idx     = IRQ_IDX(irq);
 624         int irq_bit     = 1 << irq_idx;
 625
 626         if (irq_src == 1) {
 627                 via1[vIFR] = irq_bit;
 628         } else if (irq_src == 2) {
 629                 via2[gIFR] = irq_bit | rbv_clear;
 630         } else if (irq_src == 7) {
 631                 /* FIXME: There is no way to clear an individual nubus slot
 632                  * IRQ flag, other than getting the device to do it.
 633                  */
 634         }
 635 }
 636
 637 /*
 638  * Returns nonzero if an interrupt is pending on the given
 639  * VIA/IRQ combination.
 640  */
 641
 642 int via_irq_pending(int irq)
 643 {
 644         int irq_src     = IRQ_SRC(irq);
 645         int irq_idx     = IRQ_IDX(irq);
 646         int irq_bit     = 1 << irq_idx;
 647
 648         if (irq_src == 1) {
 649                 return via1[vIFR] & irq_bit;
 650         } else if (irq_src == 2) {
 651                 return via2[gIFR] & irq_bit;
 652         } else if (irq_src == 7) {
 653                 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
 654                 return ~via2[gBufA] & irq_bit;
 655         }
 656         return 0;
 657 }