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/module.h>
  31 #include <linux/irq.h>
  32
  33 #include <asm/macintosh.h>
  34 #include <asm/macints.h>
  35 #include <asm/mac_via.h>
  36 #include <asm/mac_psc.h>
  37 #include <asm/mac_oss.h>
  38
  39 volatile __u8 *via1, *via2;
  40 int rbv_present;
  41 int via_alt_mapping;
  42 EXPORT_SYMBOL(via_alt_mapping);
  43 static __u8 rbv_clear;
  44
  45 /*
  46  * Globals for accessing the VIA chip registers without having to
  47  * check if we're hitting a real VIA or an RBV. Normally you could
  48  * just hit the combined register (ie, vIER|rIER) but that seems to
  49  * break on AV Macs...probably because they actually decode more than
  50  * eight address bits. Why can't Apple engineers at least be
  51  * _consistently_ lazy?                          - 1999-05-21 (jmt)
  52  */
  53
  54 static int gIER,gIFR,gBufA,gBufB;
  55
  56 /*
  57  * Timer defs.
  58  */
  59
  60 #define TICK_SIZE               10000
  61 #define MAC_CLOCK_TICK          (783300/HZ)             /* ticks per HZ */
  62 #define MAC_CLOCK_LOW           (MAC_CLOCK_TICK&0xFF)
  63 #define MAC_CLOCK_HIGH          (MAC_CLOCK_TICK>>8)
  64
  65
  66 /*
  67  * On Macs with a genuine VIA chip there is no way to mask an individual slot
  68  * interrupt. This limitation also seems to apply to VIA clone logic cores in
  69  * Quadra-like ASICs. (RBV and OSS machines don't have this limitation.)
  70  *
  71  * We used to fake it by configuring the relevent VIA pin as an output
  72  * (to mask the interrupt) or input (to unmask). That scheme did not work on
  73  * (at least) the Quadra 700. A NuBus card's /NMRQ signal is an open-collector
  74  * circuit (see Designing Cards and Drivers for Macintosh II and Macintosh SE,
  75  * p. 10-11 etc) but VIA outputs are not (see datasheet).
  76  *
  77  * Driving these outputs high must cause the VIA to source current and the
  78  * card to sink current when it asserts /NMRQ. Current will flow but the pin
  79  * voltage is uncertain and so the /NMRQ condition may still cause a transition
  80  * at the VIA2 CA1 input (which explains the lost interrupts). A side effect
  81  * is that a disabled slot IRQ can never be tested as pending or not.
  82  *
  83  * Driving these outputs low doesn't work either. All the slot /NMRQ lines are
  84  * (active low) OR'd together to generate the CA1 (aka "SLOTS") interrupt (see
  85  * The Guide To Macintosh Family Hardware, 2nd edition p. 167). If we drive a
  86  * disabled /NMRQ line low, the falling edge immediately triggers a CA1
  87  * interrupt and all slot interrupts after that will generate no transition
  88  * and therefore no interrupt, even after being re-enabled.
  89  *
  90  * So we make the VIA port A I/O lines inputs and use nubus_disabled to keep
  91  * track of their states. When any slot IRQ becomes disabled we mask the CA1
  92  * umbrella interrupt. Only when all slot IRQs become enabled do we unmask
  93  * the CA1 interrupt. It must remain enabled even when cards have no interrupt
  94  * handler registered. Drivers must therefore disable a slot interrupt at the
  95  * device before they call free_irq (like shared and autovector interrupts).
  96  *
  97  * There is also a related problem when MacOS is used to boot Linux. A network
  98  * card brought up by a MacOS driver may raise an interrupt while Linux boots.
  99  * This can be fatal since it can't be handled until the right driver loads
 100  * (if such a driver exists at all). Apparently related to this hardware
 101  * limitation, "Designing Cards and Drivers", p. 9-8, says that a slot
 102  * interrupt with no driver would crash MacOS (the book was written before
 103  * the appearance of Macs with RBV or OSS).
 104  */
 105
 106 static u8 nubus_disabled;
 107
 108 void via_debug_dump(void);
 109
 110 /*
 111  * Initialize the VIAs
 112  *
 113  * First we figure out where they actually _are_ as well as what type of
 114  * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
 115  * Then we pretty much clear them out and disable all IRQ sources.
 116  *
 117  * Note: the OSS is actually "detected" here and not in oss_init(). It just
 118  *       seems more logical to do it here since via_init() needs to know
 119  *       these things anyways.
 120  */
 121
 122 void __init via_init(void)
 123 {
 124         switch(macintosh_config->via_type) {
 125
 126                 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
 127
 128                 case MAC_VIA_IICI:
 129                         via1 = (void *) VIA1_BASE;
 130                         if (macintosh_config->ident == MAC_MODEL_IIFX) {
 131                                 via2 = NULL;
 132                                 rbv_present = 0;
 133                                 oss_present = 1;
 134                         } else {
 135                                 via2 = (void *) RBV_BASE;
 136                                 rbv_present = 1;
 137                                 oss_present = 0;
 138                         }
 139                         if (macintosh_config->ident == MAC_MODEL_LCIII) {
 140                                 rbv_clear = 0x00;
 141                         } else {
 142                                 /* on most RBVs (& unlike the VIAs), you   */
 143                                 /* need to set bit 7 when you write to IFR */
 144                                 /* in order for your clear to occur.       */
 145                                 rbv_clear = 0x80;
 146                         }
 147                         gIER = rIER;
 148                         gIFR = rIFR;
 149                         gBufA = rSIFR;
 150                         gBufB = rBufB;
 151                         break;
 152
 153                 /* Quadra and early MacIIs agree on the VIA locations */
 154
 155                 case MAC_VIA_QUADRA:
 156                 case MAC_VIA_II:
 157                         via1 = (void *) VIA1_BASE;
 158                         via2 = (void *) VIA2_BASE;
 159                         rbv_present = 0;
 160                         oss_present = 0;
 161                         rbv_clear = 0x00;
 162                         gIER = vIER;
 163                         gIFR = vIFR;
 164                         gBufA = vBufA;
 165                         gBufB = vBufB;
 166                         break;
 167                 default:
 168                         panic("UNKNOWN VIA TYPE");
 169         }
 170
 171         printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
 172
 173         printk(KERN_INFO "VIA2 at %p is ", via2);
 174         if (rbv_present) {
 175                 printk("an RBV\n");
 176         } else if (oss_present) {
 177                 printk("an OSS\n");
 178         } else {
 179                 printk("a 6522 or clone\n");
 180         }
 181
 182 #ifdef DEBUG_VIA
 183         via_debug_dump();
 184 #endif
 185
 186         /*
 187          * Shut down all IRQ sources, reset the timers, and
 188          * kill the timer latch on VIA1.
 189          */
 190
 191         via1[vIER] = 0x7F;
 192         via1[vIFR] = 0x7F;
 193         via1[vT1LL] = 0;
 194         via1[vT1LH] = 0;
 195         via1[vT1CL] = 0;
 196         via1[vT1CH] = 0;
 197         via1[vT2CL] = 0;
 198         via1[vT2CH] = 0;
 199         via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
 200         via1[vACR] &= ~0x03; /* disable port A & B latches */
 201
 202         /*
 203          * SE/30: disable video IRQ
 204          * XXX: testing for SE/30 VBL
 205          */
 206
 207         if (macintosh_config->ident == MAC_MODEL_SE30) {
 208                 via1[vDirB] |= 0x40;
 209                 via1[vBufB] |= 0x40;
 210         }
 211
 212         /*
 213          * Set the RTC bits to a known state: all lines to outputs and
 214          * RTC disabled (yes that's 0 to enable and 1 to disable).
 215          */
 216
 217         via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
 218         via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
 219
 220         /* Everything below this point is VIA2/RBV only... */
 221
 222         if (oss_present)
 223                 return;
 224
 225         if ((macintosh_config->via_type == MAC_VIA_QUADRA) &&
 226             (macintosh_config->adb_type != MAC_ADB_PB1) &&
 227             (macintosh_config->adb_type != MAC_ADB_PB2) &&
 228             (macintosh_config->ident    != MAC_MODEL_C660) &&
 229             (macintosh_config->ident    != MAC_MODEL_Q840)) {
 230                 via_alt_mapping = 1;
 231                 via1[vDirB] |= 0x40;
 232                 via1[vBufB] &= ~0x40;
 233         } else {
 234                 via_alt_mapping = 0;
 235         }
 236
 237         /*
 238          * Now initialize VIA2. For RBV we just kill all interrupts;
 239          * for a regular VIA we also reset the timers and stuff.
 240          */
 241
 242         via2[gIER] = 0x7F;
 243         via2[gIFR] = 0x7F | rbv_clear;
 244         if (!rbv_present) {
 245                 via2[vT1LL] = 0;
 246                 via2[vT1LH] = 0;
 247                 via2[vT1CL] = 0;
 248                 via2[vT1CH] = 0;
 249                 via2[vT2CL] = 0;
 250                 via2[vT2CH] = 0;
 251                 via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
 252                 via2[vACR] &= ~0x03; /* disable port A & B latches */
 253         }
 254
 255         /* Everything below this point is VIA2 only... */
 256
 257         if (rbv_present)
 258                 return;
 259
 260         /*
 261          * Set vPCR for control line interrupts.
 262          *
 263          * CA1 (SLOTS IRQ), CB1 (ASC IRQ): negative edge trigger.
 264          *
 265          * Macs with ESP SCSI have a negative edge triggered SCSI interrupt.
 266          * Testing reveals that PowerBooks do too. However, the SE/30
 267          * schematic diagram shows an active high NCR5380 IRQ line.
 268          */
 269
 270         pr_debug("VIA2 vPCR is 0x%02X\n", via2[vPCR]);
 271         if (macintosh_config->via_type == MAC_VIA_II) {
 272                 /* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, pos. edge */
 273                 via2[vPCR] = 0x66;
 274         } else {
 275                 /* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, neg. edge */
 276                 via2[vPCR] = 0x22;
 277         }
 278 }
 279
 280 /*
 281  * Start the 100 Hz clock
 282  */
 283
 284 void __init via_init_clock(irq_handler_t func)
 285 {
 286         via1[vACR] |= 0x40;
 287         via1[vT1LL] = MAC_CLOCK_LOW;
 288         via1[vT1LH] = MAC_CLOCK_HIGH;
 289         via1[vT1CL] = MAC_CLOCK_LOW;
 290         via1[vT1CH] = MAC_CLOCK_HIGH;
 291
 292         if (request_irq(IRQ_MAC_TIMER_1, func, 0, "timer", func))
 293                 pr_err("Couldn't register %s interrupt\n", "timer");
 294 }
 295
 296 /*
 297  * Debugging dump, used in various places to see what's going on.
 298  */
 299
 300 void via_debug_dump(void)
 301 {
 302         printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 303                 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
 304         printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 305                 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
 306         if (oss_present) {
 307                 printk(KERN_DEBUG "VIA2: <OSS>\n");
 308         } else if (rbv_present) {
 309                 printk(KERN_DEBUG "VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
 310                         (uint) via2[rIFR], (uint) via2[rIER]);
 311                 printk(KERN_DEBUG "      SIFR = 0x%02X SIER = 0x%02X\n",
 312                         (uint) via2[rSIFR], (uint) via2[rSIER]);
 313         } else {
 314                 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 315                         (uint) via2[vDirA], (uint) via2[vDirB],
 316                         (uint) via2[vACR]);
 317                 printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 318                         (uint) via2[vPCR],
 319                         (uint) via2[vIFR], (uint) via2[vIER]);
 320         }
 321 }
 322
 323 /*
 324  * This is always executed with interrupts disabled.
 325  *
 326  * TBI: get time offset between scheduling timer ticks
 327  */
 328
 329 u32 mac_gettimeoffset(void)
 330 {
 331         unsigned long ticks, offset = 0;
 332
 333         /* read VIA1 timer 2 current value */
 334         ticks = via1[vT1CL] | (via1[vT1CH] << 8);
 335         /* The probability of underflow is less than 2% */
 336         if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
 337                 /* Check for pending timer interrupt in VIA1 IFR */
 338                 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
 339
 340         ticks = MAC_CLOCK_TICK - ticks;
 341         ticks = ticks * 10000L / MAC_CLOCK_TICK;
 342
 343         return (ticks + offset) * 1000;
 344 }
 345
 346 /*
 347  * Flush the L2 cache on Macs that have it by flipping
 348  * the system into 24-bit mode for an instant.
 349  */
 350
 351 void via_flush_cache(void)
 352 {
 353         via2[gBufB] &= ~VIA2B_vMode32;
 354         via2[gBufB] |= VIA2B_vMode32;
 355 }
 356
 357 /*
 358  * Return the status of the L2 cache on a IIci
 359  */
 360
 361 int via_get_cache_disable(void)
 362 {
 363         /* Safeguard against being called accidentally */
 364         if (!via2) {
 365                 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
 366                 return 1;
 367         }
 368
 369         return (int) via2[gBufB] & VIA2B_vCDis;
 370 }
 371
 372 /*
 373  * Initialize VIA2 for Nubus access
 374  */
 375
 376 void __init via_nubus_init(void)
 377 {
 378         /* unlock nubus transactions */
 379
 380         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 381             (macintosh_config->adb_type != MAC_ADB_PB2)) {
 382                 /* set the line to be an output on non-RBV machines */
 383                 if (!rbv_present)
 384                         via2[vDirB] |= 0x02;
 385
 386                 /* this seems to be an ADB bit on PMU machines */
 387                 /* according to MkLinux.  -- jmt               */
 388                 via2[gBufB] |= 0x02;
 389         }
 390
 391         /*
 392          * Disable the slot interrupts. On some hardware that's not possible.
 393          * On some hardware it's unclear what all of these I/O lines do.
 394          */
 395
 396         switch (macintosh_config->via_type) {
 397         case MAC_VIA_II:
 398         case MAC_VIA_QUADRA:
 399                 pr_debug("VIA2 vDirA is 0x%02X\n", via2[vDirA]);
 400                 break;
 401         case MAC_VIA_IICI:
 402                 /* RBV. Disable all the slot interrupts. SIER works like IER. */
 403                 via2[rSIER] = 0x7F;
 404                 break;
 405         }
 406 }
 407
 408 void via_nubus_irq_startup(int irq)
 409 {
 410         int irq_idx = IRQ_IDX(irq);
 411
 412         switch (macintosh_config->via_type) {
 413         case MAC_VIA_II:
 414         case MAC_VIA_QUADRA:
 415                 /* Make the port A line an input. Probably redundant. */
 416                 if (macintosh_config->via_type == MAC_VIA_II) {
 417                         /* The top two bits are RAM size outputs. */
 418                         via2[vDirA] &= 0xC0 | ~(1 << irq_idx);
 419                 } else {
 420                         /* Allow NuBus slots 9 through F. */
 421                         via2[vDirA] &= 0x80 | ~(1 << irq_idx);
 422                 }
 423                 /* fall through */
 424         case MAC_VIA_IICI:
 425                 via_irq_enable(irq);
 426                 break;
 427         }
 428 }
 429
 430 void via_nubus_irq_shutdown(int irq)
 431 {
 432         switch (macintosh_config->via_type) {
 433         case MAC_VIA_II:
 434         case MAC_VIA_QUADRA:
 435                 /* Ensure that the umbrella CA1 interrupt remains enabled. */
 436                 via_irq_enable(irq);
 437                 break;
 438         case MAC_VIA_IICI:
 439                 via_irq_disable(irq);
 440                 break;
 441         }
 442 }
 443
 444 /*
 445  * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
 446  * via6522.c :-), disable/pending masks added.
 447  */
 448
 449 void via1_irq(unsigned int irq, struct irq_desc *desc)
 450 {
 451         int irq_num;
 452         unsigned char irq_bit, events;
 453
 454         events = via1[vIFR] & via1[vIER] & 0x7F;
 455         if (!events)
 456                 return;
 457
 458         irq_num = VIA1_SOURCE_BASE;
 459         irq_bit = 1;
 460         do {
 461                 if (events & irq_bit) {
 462                         via1[vIFR] = irq_bit;
 463                         generic_handle_irq(irq_num);
 464                 }
 465                 ++irq_num;
 466                 irq_bit <<= 1;
 467         } while (events >= irq_bit);
 468 }
 469
 470 static void via2_irq(unsigned int irq, struct irq_desc *desc)
 471 {
 472         int irq_num;
 473         unsigned char irq_bit, events;
 474
 475         events = via2[gIFR] & via2[gIER] & 0x7F;
 476         if (!events)
 477                 return;
 478
 479         irq_num = VIA2_SOURCE_BASE;
 480         irq_bit = 1;
 481         do {
 482                 if (events & irq_bit) {
 483                         via2[gIFR] = irq_bit | rbv_clear;
 484                         generic_handle_irq(irq_num);
 485                 }
 486                 ++irq_num;
 487                 irq_bit <<= 1;
 488         } while (events >= irq_bit);
 489 }
 490
 491 /*
 492  * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
 493  * VIA2 dispatcher as a fast interrupt handler.
 494  */
 495
 496 void via_nubus_irq(unsigned int irq, struct irq_desc *desc)
 497 {
 498         int slot_irq;
 499         unsigned char slot_bit, events;
 500
 501         events = ~via2[gBufA] & 0x7F;
 502         if (rbv_present)
 503                 events &= via2[rSIER];
 504         else
 505                 events &= ~via2[vDirA];
 506         if (!events)
 507                 return;
 508
 509         do {
 510                 slot_irq = IRQ_NUBUS_F;
 511                 slot_bit = 0x40;
 512                 do {
 513                         if (events & slot_bit) {
 514                                 events &= ~slot_bit;
 515                                 generic_handle_irq(slot_irq);
 516                         }
 517                         --slot_irq;
 518                         slot_bit >>= 1;
 519                 } while (events);
 520
 521                 /* clear the CA1 interrupt and make certain there's no more. */
 522                 via2[gIFR] = 0x02 | rbv_clear;
 523                 events = ~via2[gBufA] & 0x7F;
 524                 if (rbv_present)
 525                         events &= via2[rSIER];
 526                 else
 527                         events &= ~via2[vDirA];
 528         } while (events);
 529 }
 530
 531 /*
 532  * Register the interrupt dispatchers for VIA or RBV machines only.
 533  */
 534
 535 void __init via_register_interrupts(void)
 536 {
 537         if (via_alt_mapping) {
 538                 /* software interrupt */
 539                 irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
 540                 /* via1 interrupt */
 541                 irq_set_chained_handler(IRQ_AUTO_6, via1_irq);
 542         } else {
 543                 irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
 544         }
 545         irq_set_chained_handler(IRQ_AUTO_2, via2_irq);
 546         irq_set_chained_handler(IRQ_MAC_NUBUS, via_nubus_irq);
 547 }
 548
 549 void via_irq_enable(int irq) {
 550         int irq_src     = IRQ_SRC(irq);
 551         int irq_idx     = IRQ_IDX(irq);
 552
 553 #ifdef DEBUG_IRQUSE
 554         printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
 555 #endif
 556
 557         if (irq_src == 1) {
 558                 via1[vIER] = IER_SET_BIT(irq_idx);
 559         } else if (irq_src == 2) {
 560                 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
 561                         via2[gIER] = IER_SET_BIT(irq_idx);
 562         } else if (irq_src == 7) {
 563                 switch (macintosh_config->via_type) {
 564                 case MAC_VIA_II:
 565                 case MAC_VIA_QUADRA:
 566                         nubus_disabled &= ~(1 << irq_idx);
 567                         /* Enable the CA1 interrupt when no slot is disabled. */
 568                         if (!nubus_disabled)
 569                                 via2[gIER] = IER_SET_BIT(1);
 570                         break;
 571                 case MAC_VIA_IICI:
 572                         /* On RBV, enable the slot interrupt.
 573                          * SIER works like IER.
 574                          */
 575                         via2[rSIER] = IER_SET_BIT(irq_idx);
 576                         break;
 577                 }
 578         }
 579 }
 580
 581 void via_irq_disable(int irq) {
 582         int irq_src     = IRQ_SRC(irq);
 583         int irq_idx     = IRQ_IDX(irq);
 584
 585 #ifdef DEBUG_IRQUSE
 586         printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
 587 #endif
 588
 589         if (irq_src == 1) {
 590                 via1[vIER] = IER_CLR_BIT(irq_idx);
 591         } else if (irq_src == 2) {
 592                 via2[gIER] = IER_CLR_BIT(irq_idx);
 593         } else if (irq_src == 7) {
 594                 switch (macintosh_config->via_type) {
 595                 case MAC_VIA_II:
 596                 case MAC_VIA_QUADRA:
 597                         nubus_disabled |= 1 << irq_idx;
 598                         if (nubus_disabled)
 599                                 via2[gIER] = IER_CLR_BIT(1);
 600                         break;
 601                 case MAC_VIA_IICI:
 602                         via2[rSIER] = IER_CLR_BIT(irq_idx);
 603                         break;
 604                 }
 605         }
 606 }
 607
 608 void via1_set_head(int head)
 609 {
 610         if (head == 0)
 611                 via1[vBufA] &= ~VIA1A_vHeadSel;
 612         else
 613                 via1[vBufA] |= VIA1A_vHeadSel;
 614 }
 615 EXPORT_SYMBOL(via1_set_head);
 616
 617 int via2_scsi_drq_pending(void)
 618 {
 619         return via2[gIFR] & (1 << IRQ_IDX(IRQ_MAC_SCSIDRQ));
 620 }
 621 EXPORT_SYMBOL(via2_scsi_drq_pending);