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  * PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
  17  * by Erik Vogan and adapted to Linux by Joshua M. Thompson (funaho@jurai.org)
  18  *
  19  */
  20
  21 #include <linux/types.h>
  22 #include <linux/kernel.h>
  23 #include <linux/mm.h>
  24 #include <linux/delay.h>
  25 #include <linux/init.h>
  26
  27 #include <linux/ide.h>
  28
  29 #include <asm/traps.h>
  30 #include <asm/bootinfo.h>
  31 #include <asm/macintosh.h>
  32 #include <asm/macints.h>
  33 #include <asm/machw.h>
  34 #include <asm/mac_via.h>
  35 #include <asm/mac_psc.h>
  36
  37 volatile __u8 *via1, *via2;
  38 #if 0
  39 /* See note in mac_via.h about how this is possibly not useful */
  40 volatile long *via_memory_bogon=(long *)&via_memory_bogon;
  41 #endif
  42 int  rbv_present,via_alt_mapping;
  43 __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  * _consistantly_ 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 static int  nubus_active = 0;
  66
  67 void via_debug_dump(void);
  68 void via1_irq(int, void *, struct pt_regs *);
  69 void via2_irq(int, void *, struct pt_regs *);
  70 void via_nubus_irq(int, void *, struct pt_regs *);
  71 void via_irq_enable(int irq);
  72 void via_irq_disable(int irq);
  73 void via_irq_clear(int irq);
  74
  75 extern void mac_bang(int, void *, struct pt_regs *);
  76 extern void mac_scc_dispatch(int, void *, struct pt_regs *);
  77 extern int oss_present;
  78
  79 /*
  80  * Initialize the VIAs
  81  *
  82  * First we figure out where they actually _are_ as well as what type of
  83  * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
  84  * Then we pretty much clear them out and disable all IRQ sources.
  85  *
  86  * Note: the OSS is actually "detected" here and not in oss_init(). It just
  87  *       seems more logical to do it here since via_init() needs to know
  88  *       these things anyways.
  89  */
  90
  91 void __init via_init(void)
  92 {
  93         switch(macintosh_config->via_type) {
  94
  95                 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
  96
  97                 case MAC_VIA_IIci:
  98                         via1 = (void *) VIA1_BASE;
  99                         if (macintosh_config->ident == MAC_MODEL_IIFX) {
 100                                 via2 = NULL;
 101                                 rbv_present = 0;
 102                                 oss_present = 1;
 103                         } else {
 104                                 via2 = (void *) RBV_BASE;
 105                                 rbv_present = 1;
 106                                 oss_present = 0;
 107                         }
 108                         if (macintosh_config->ident == MAC_MODEL_LCIII) {
 109                                 rbv_clear = 0x00;
 110                         } else {
 111                                 /* on most RBVs (& unlike the VIAs), you   */
 112                                 /* need to set bit 7 when you write to IFR */
 113                                 /* in order for your clear to occur.       */
 114                                 rbv_clear = 0x80;
 115                         }
 116                         gIER = rIER;
 117                         gIFR = rIFR;
 118                         gBufA = rSIFR;
 119                         gBufB = rBufB;
 120                         break;
 121
 122                 /* Quadra and early MacIIs agree on the VIA locations */
 123
 124                 case MAC_VIA_QUADRA:
 125                 case MAC_VIA_II:
 126                         via1 = (void *) VIA1_BASE;
 127                         via2 = (void *) VIA2_BASE;
 128                         rbv_present = 0;
 129                         oss_present = 0;
 130                         rbv_clear = 0x00;
 131                         gIER = vIER;
 132                         gIFR = vIFR;
 133                         gBufA = vBufA;
 134                         gBufB = vBufB;
 135                         break;
 136                 default:
 137                         panic("UNKNOWN VIA TYPE");
 138         }
 139
 140         printk("VIA1 at %p is a 6522 or clone\n", via1);
 141
 142         printk("VIA2 at %p is ", via2);
 143         if (rbv_present) {
 144                 printk("an RBV\n");
 145         } else if (oss_present) {
 146                 printk("an OSS\n");
 147         } else {
 148                 printk("a 6522 or clone\n");
 149         }
 150
 151 #ifdef DEBUG_VIA
 152         via_debug_dump();
 153 #endif
 154
 155         /*
 156          * Shut down all IRQ sources, reset the timers, and
 157          * kill the timer latch on VIA1.
 158          */
 159
 160         via1[vIER] = 0x7F;
 161         via1[vIFR] = 0x7F;
 162         via1[vT1LL] = 0;
 163         via1[vT1LH] = 0;
 164         via1[vT1CL] = 0;
 165         via1[vT1CH] = 0;
 166         via1[vT2CL] = 0;
 167         via1[vT2CH] = 0;
 168         via1[vACR] &= 0x3F;
 169
 170         /*
 171          * SE/30: disable video IRQ
 172          * XXX: testing for SE/30 VBL
 173          */
 174
 175         if (macintosh_config->ident == MAC_MODEL_SE30) {
 176                 via1[vDirB] |= 0x40;
 177                 via1[vBufB] |= 0x40;
 178         }
 179
 180         /*
 181          * Set the RTC bits to a known state: all lines to outputs and
 182          * RTC disabled (yes that's 0 to enable and 1 to disable).
 183          */
 184
 185         via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
 186         via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
 187
 188         /* Everything below this point is VIA2/RBV only... */
 189
 190         if (oss_present) return;
 191
 192 #if 1
 193         /* Some machines support an alternate IRQ mapping that spreads  */
 194         /* Ethernet and Sound out to their own autolevel IRQs and moves */
 195         /* VIA1 to level 6. A/UX uses this mapping and we do too.  Note */
 196         /* that the IIfx emulates this alternate mapping using the OSS. */
 197
 198         switch(macintosh_config->ident) {
 199                 case MAC_MODEL_C610:
 200                 case MAC_MODEL_Q610:
 201                 case MAC_MODEL_C650:
 202                 case MAC_MODEL_Q650:
 203                 case MAC_MODEL_Q700:
 204                 case MAC_MODEL_Q800:
 205                 case MAC_MODEL_Q900:
 206                 case MAC_MODEL_Q950:
 207                         via_alt_mapping = 1;
 208                         via1[vDirB] |= 0x40;
 209                         via1[vBufB] &= ~0x40;
 210                         break;
 211                 default:
 212                         via_alt_mapping = 0;
 213                         break;
 214         }
 215 #else
 216         /* The alernate IRQ mapping seems to just not work. Anyone with a   */
 217         /* supported machine is welcome to take a stab at fixing it. It     */
 218         /* _should_ work on the following Quadras: 610,650,700,800,900,950  */
 219         /*                                               - 1999-06-12 (jmt) */
 220
 221         via_alt_mapping = 0;
 222 #endif
 223
 224         /*
 225          * Now initialize VIA2. For RBV we just kill all interrupts;
 226          * for a regular VIA we also reset the timers and stuff.
 227          */
 228
 229         via2[gIER] = 0x7F;
 230         via2[gIFR] = 0x7F | rbv_clear;
 231         if (!rbv_present) {
 232                 via2[vT1LL] = 0;
 233                 via2[vT1LH] = 0;
 234                 via2[vT1CL] = 0;
 235                 via2[vT1CH] = 0;
 236                 via2[vT2CL] = 0;
 237                 via2[vT2CH] = 0;
 238                 via2[vACR] &= 0x3F;
 239         }
 240 }
 241
 242 /*
 243  * Start the 100 Hz clock
 244  */
 245
 246 void __init via_init_clock(void (*func)(int, void *, struct pt_regs *))
 247 {
 248         via1[vACR] |= 0x40;
 249         via1[vT1LL] = MAC_CLOCK_LOW;
 250         via1[vT1LH] = MAC_CLOCK_HIGH;
 251         via1[vT1CL] = MAC_CLOCK_LOW;
 252         via1[vT1CH] = MAC_CLOCK_HIGH;
 253
 254         request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
 255 }
 256
 257 /*
 258  * Register the interrupt dispatchers for VIA or RBV machines only.
 259  */
 260
 261 void __init via_register_interrupts(void)
 262 {
 263         if (via_alt_mapping) {
 264                 sys_request_irq(IRQ_AUTO_1, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 265                                 "software", (void *) via1);
 266                 sys_request_irq(IRQ_AUTO_6, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 267                                 "via1", (void *) via1);
 268         } else {
 269                 sys_request_irq(IRQ_AUTO_1, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 270                                 "via1", (void *) via1);
 271 #if 0 /* interferes with serial on some machines */
 272                 if (!psc_present) {
 273                         sys_request_irq(IRQ_AUTO_6, mac_bang, IRQ_FLG_LOCK,
 274                                         "Off Switch", mac_bang);
 275                 }
 276 #endif
 277         }
 278         sys_request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 279                         "via2", (void *) via2);
 280         if (!psc_present) {
 281                 sys_request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
 282                                 "scc", mac_scc_dispatch);
 283         }
 284         request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 285                         "nubus", (void *) via2);
 286 }
 287
 288 /*
 289  * Debugging dump, used in various places to see what's going on.
 290  */
 291
 292 void via_debug_dump(void)
 293 {
 294         printk("VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 295                 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
 296         printk("         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 297                 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
 298         if (oss_present) {
 299                 printk("VIA2: <OSS>\n");
 300         } else if (rbv_present) {
 301                 printk("VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
 302                         (uint) via2[rIFR], (uint) via2[rIER]);
 303                 printk("      SIFR = 0x%02X SIER = 0x%02X\n",
 304                         (uint) via2[rSIFR], (uint) via2[rSIER]);
 305         } else {
 306                 printk("VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 307                         (uint) via2[vDirA], (uint) via2[vDirB],
 308                         (uint) via2[vACR]);
 309                 printk("         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 310                         (uint) via2[vPCR],
 311                         (uint) via2[vIFR], (uint) via2[vIER]);
 312         }
 313 }
 314
 315 /*
 316  * This is always executed with interrupts disabled.
 317  *
 318  * TBI: get time offset between scheduling timer ticks
 319  */
 320
 321 unsigned long mac_gettimeoffset (void)
 322 {
 323         unsigned long ticks, offset = 0;
 324
 325         /* read VIA1 timer 2 current value */
 326         ticks = via1[vT1CL] | (via1[vT1CH] << 8);
 327         /* The probability of underflow is less than 2% */
 328         if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
 329                 /* Check for pending timer interrupt in VIA1 IFR */
 330                 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
 331
 332         ticks = MAC_CLOCK_TICK - ticks;
 333         ticks = ticks * 10000L / MAC_CLOCK_TICK;
 334
 335         return ticks + offset;
 336 }
 337
 338 /*
 339  * Flush the L2 cache on Macs that have it by flipping
 340  * the system into 24-bit mode for an instant.
 341  */
 342
 343 void via_flush_cache(void)
 344 {
 345         via2[gBufB] &= ~VIA2B_vMode32;
 346         via2[gBufB] |= VIA2B_vMode32;
 347 }
 348
 349 /*
 350  * Return the status of the L2 cache on a IIci
 351  */
 352
 353 int via_get_cache_disable(void)
 354 {
 355         /* Safeguard against being called accidentally */
 356         if (!via2) {
 357                 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
 358                 return 1;
 359         }
 360
 361         return (int) via2[gBufB] & VIA2B_vCDis;
 362 }
 363
 364 /*
 365  * Initialize VIA2 for Nubus access
 366  */
 367
 368 void __init via_nubus_init(void)
 369 {
 370         /* don't set nubus_active = 0 here, it kills the Baboon */
 371         /* interrupt that we've already registered.             */
 372
 373         /* unlock nubus transactions */
 374
 375         if (!rbv_present) {
 376                 /* set the line to be an output on non-RBV machines */
 377                 via2[vDirB] |= 0x02;
 378         }
 379
 380         /* this seems to be an ADB bit on PMU machines */
 381         /* according to MkLinux.  -- jmt               */
 382
 383         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 384             (macintosh_config->adb_type != MAC_ADB_PB2)) {
 385                 via2[gBufB] |= 0x02;
 386         }
 387
 388         /* disable nubus slot interrupts. */
 389         if (rbv_present) {
 390                 via2[rSIER] = 0x7F;
 391                 via2[rSIER] = nubus_active | 0x80;
 392         } else {
 393                 via2[vBufA] = 0xFF;
 394                 via2[vDirA] = ~nubus_active;
 395         }
 396 }
 397
 398 /*
 399  * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
 400  * via6522.c :-), disable/pending masks added.
 401  *
 402  * The new interrupt architecture in macints.c takes care of a lot of the
 403  * gruntwork for us, including tallying the interrupts and calling the
 404  * handlers on the linked list. All we need to do here is basically generate
 405  * the machspec interrupt number after clearing the interrupt.
 406  */
 407
 408 void via1_irq(int irq, void *dev_id, struct pt_regs *regs)
 409 {
 410         int irq_bit, i;
 411         unsigned char events, mask;
 412
 413         irq -= VEC_SPUR;
 414
 415         mask = via1[vIER] & 0x7F;
 416         if (!(events = via1[vIFR] & mask)) return;
 417
 418         for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
 419                 if (events & irq_bit) {
 420                         via1[vIER] = irq_bit;
 421                         mac_do_irq_list(VIA1_SOURCE_BASE + i, regs);
 422                         via1[vIFR] = irq_bit;
 423                         via1[vIER] = irq_bit | 0x80;
 424                 }
 425
 426         if (!oss_present) {
 427                 /* This (still) seems to be necessary to get IDE
 428                    working.  However, if you enable VBL interrupts,
 429                    you're screwed... */
 430                 /* FIXME: should we check the SLOTIRQ bit before
 431                    pulling this stunt? */
 432                 /* No, it won't be set. that's why we're doing this. */
 433                 via_irq_disable(IRQ_MAC_NUBUS);
 434                 via_irq_clear(IRQ_MAC_NUBUS);
 435                 mac_do_irq_list(IRQ_MAC_NUBUS, regs);
 436                 via_irq_enable(IRQ_MAC_NUBUS);
 437         }
 438 }
 439
 440 void via2_irq(int irq, void *dev_id, struct pt_regs *regs)
 441 {
 442         int irq_bit, i;
 443         unsigned char events, mask;
 444
 445         irq -= VEC_SPUR;
 446
 447         mask = via2[gIER] & 0x7F;
 448         if (!(events = via2[gIFR] & mask)) return;
 449
 450         for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
 451                 if (events & irq_bit) {
 452                         via2[gIER] = irq_bit;
 453                         mac_do_irq_list(VIA2_SOURCE_BASE + i, regs);
 454                         via2[gIFR] = irq_bit | rbv_clear;
 455                         via2[gIER] = irq_bit | 0x80;
 456                 }
 457 }
 458
 459 /*
 460  * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
 461  * VIA2 dispatcher as a fast interrupt handler.
 462  */
 463
 464 void via_nubus_irq(int irq, void *dev_id, struct pt_regs *regs)
 465 {
 466         int irq_bit, i;
 467         unsigned char events;
 468
 469         if (!(events = ~via2[gBufA] & nubus_active)) return;
 470
 471         for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1) {
 472                 if (events & irq_bit) {
 473                         via_irq_disable(NUBUS_SOURCE_BASE + i);
 474                         mac_do_irq_list(NUBUS_SOURCE_BASE + i, regs);
 475                         via_irq_enable(NUBUS_SOURCE_BASE + i);
 476                 }
 477         }
 478 }
 479
 480 void via_irq_enable(int irq) {
 481         int irq_src     = IRQ_SRC(irq);
 482         int irq_idx     = IRQ_IDX(irq);
 483         int irq_bit     = 1 << irq_idx;
 484
 485 #ifdef DEBUG_IRQUSE
 486         printk("via_irq_enable(%d)\n", irq);
 487 #endif
 488
 489         if (irq_src == 1) {
 490                 via1[vIER] = irq_bit | 0x80;
 491         } else if (irq_src == 2) {
 492                 /*
 493                  * Set vPCR for SCSI interrupts (but not on RBV)
 494                  */
 495                 if ((irq_idx == 0) && !rbv_present) {
 496                         if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
 497                                 /* CB2 (IRQ) indep. input, positive edge */
 498                                 /* CA2 (DRQ) indep. input, positive edge */
 499                                 via2[vPCR] = 0x66;
 500                         } else {
 501                                 /* CB2 (IRQ) indep. input, negative edge */
 502                                 /* CA2 (DRQ) indep. input, negative edge */
 503                                 via2[vPCR] = 0x22;
 504                         }
 505                 }
 506                 via2[gIER] = irq_bit | 0x80;
 507         } else if (irq_src == 7) {
 508                 if (rbv_present) {
 509                         /* enable the slot interrupt. SIER works like IER. */
 510                         via2[rSIER] = IER_SET_BIT(irq_idx);
 511                 } else {
 512                         /* Make sure the bit is an input, to enable the irq */
 513                         via2[vDirA] &= ~irq_bit;
 514                 }
 515                 nubus_active |= irq_bit;
 516         }
 517 }
 518
 519 void via_irq_disable(int irq) {
 520         int irq_src     = IRQ_SRC(irq);
 521         int irq_idx     = IRQ_IDX(irq);
 522         int irq_bit     = 1 << irq_idx;
 523
 524 #ifdef DEBUG_IRQUSE
 525         printk("via_irq_disable(%d)\n", irq);
 526 #endif
 527
 528         if (irq_src == 1) {
 529                 via1[vIER] = irq_bit;
 530         } else if (irq_src == 2) {
 531                 via2[gIER] = irq_bit;
 532         } else if (irq_src == 7) {
 533                 if (rbv_present) {
 534                         /* disable the slot interrupt.  SIER works like IER. */
 535                         via2[rSIER] = IER_CLR_BIT(irq_idx);
 536                 } else {
 537                         /* disable the nubus irq by changing dir to output */
 538                         via2[vDirA] |= irq_bit;
 539                 }
 540                 nubus_active &= ~irq_bit;
 541         }
 542 }
 543
 544 void via_irq_clear(int irq) {
 545         int irq_src     = IRQ_SRC(irq);
 546         int irq_idx     = IRQ_IDX(irq);
 547         int irq_bit     = 1 << irq_idx;
 548
 549         if (irq_src == 1) {
 550                 via1[vIFR] = irq_bit;
 551         } else if (irq_src == 2) {
 552                 via2[gIFR] = irq_bit | rbv_clear;
 553         } else if (irq_src == 7) {
 554                 /* FIXME: hmm.. */
 555         }
 556 }
 557
 558 /*
 559  * Returns nonzero if an interrupt is pending on the given
 560  * VIA/IRQ combination.
 561  */
 562
 563 int via_irq_pending(int irq)
 564 {
 565         int irq_src     = IRQ_SRC(irq);
 566         int irq_idx     = IRQ_IDX(irq);
 567         int irq_bit     = 1 << irq_idx;
 568
 569         if (irq_src == 1) {
 570                 return via1[vIFR] & irq_bit;
 571         } else if (irq_src == 2) {
 572                 return via2[gIFR] & irq_bit;
 573         } else if (irq_src == 7) {
 574                 return ~via2[gBufA] & irq_bit;
 575         }
 576         return 0;
 577 }