arch/m68k/mac/via.c

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