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 #include <linux/ide.h>
  27
  28 #include <asm/bootinfo.h>
  29 #include <asm/macintosh.h>
  30 #include <asm/macints.h>
  31 #include <asm/machw.h>
  32 #include <asm/mac_via.h>
  33 #include <asm/mac_psc.h>
  34
  35 volatile __u8 *via1, *via2;
  36 #if 0
  37 /* See note in mac_via.h about how this is possibly not useful */
  38 volatile long *via_memory_bogon=(long *)&via_memory_bogon;
  39 #endif
  40 int  rbv_present,via_alt_mapping;
  41 __u8 rbv_clear;
  42
  43 /*
  44  * Globals for accessing the VIA chip registers without having to
  45  * check if we're hitting a real VIA or an RBV. Normally you could
  46  * just hit the combined register (ie, vIER|rIER) but that seems to
  47  * break on AV Macs...probably because they actually decode more than
  48  * eight address bits. Why can't Apple engineers at least be
  49  * _consistently_ lazy?                          - 1999-05-21 (jmt)
  50  */
  51
  52 static int gIER,gIFR,gBufA,gBufB;
  53
  54 /*
  55  * Timer defs.
  56  */
  57
  58 #define TICK_SIZE               10000
  59 #define MAC_CLOCK_TICK          (783300/HZ)             /* ticks per HZ */
  60 #define MAC_CLOCK_LOW           (MAC_CLOCK_TICK&0xFF)
  61 #define MAC_CLOCK_HIGH          (MAC_CLOCK_TICK>>8)
  62
  63 static int  nubus_active;
  64
  65 void via_debug_dump(void);
  66 irqreturn_t via1_irq(int, void *);
  67 irqreturn_t via2_irq(int, void *);
  68 irqreturn_t via_nubus_irq(int, void *);
  69 void via_irq_enable(int irq);
  70 void via_irq_disable(int irq);
  71 void via_irq_clear(int irq);
  72
  73 extern irqreturn_t mac_scc_dispatch(int, void *);
  74 extern int oss_present;
  75
  76 /*
  77  * Initialize the VIAs
  78  *
  79  * First we figure out where they actually _are_ as well as what type of
  80  * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
  81  * Then we pretty much clear them out and disable all IRQ sources.
  82  *
  83  * Note: the OSS is actually "detected" here and not in oss_init(). It just
  84  *       seems more logical to do it here since via_init() needs to know
  85  *       these things anyways.
  86  */
  87
  88 void __init via_init(void)
  89 {
  90         switch(macintosh_config->via_type) {
  91
  92                 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
  93
  94                 case MAC_VIA_IIci:
  95                         via1 = (void *) VIA1_BASE;
  96                         if (macintosh_config->ident == MAC_MODEL_IIFX) {
  97                                 via2 = NULL;
  98                                 rbv_present = 0;
  99                                 oss_present = 1;
 100                         } else {
 101                                 via2 = (void *) RBV_BASE;
 102                                 rbv_present = 1;
 103                                 oss_present = 0;
 104                         }
 105                         if (macintosh_config->ident == MAC_MODEL_LCIII) {
 106                                 rbv_clear = 0x00;
 107                         } else {
 108                                 /* on most RBVs (& unlike the VIAs), you   */
 109                                 /* need to set bit 7 when you write to IFR */
 110                                 /* in order for your clear to occur.       */
 111                                 rbv_clear = 0x80;
 112                         }
 113                         gIER = rIER;
 114                         gIFR = rIFR;
 115                         gBufA = rSIFR;
 116                         gBufB = rBufB;
 117                         break;
 118
 119                 /* Quadra and early MacIIs agree on the VIA locations */
 120
 121                 case MAC_VIA_QUADRA:
 122                 case MAC_VIA_II:
 123                         via1 = (void *) VIA1_BASE;
 124                         via2 = (void *) VIA2_BASE;
 125                         rbv_present = 0;
 126                         oss_present = 0;
 127                         rbv_clear = 0x00;
 128                         gIER = vIER;
 129                         gIFR = vIFR;
 130                         gBufA = vBufA;
 131                         gBufB = vBufB;
 132                         break;
 133                 default:
 134                         panic("UNKNOWN VIA TYPE");
 135         }
 136
 137         printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
 138
 139         printk(KERN_INFO "VIA2 at %p is ", via2);
 140         if (rbv_present) {
 141                 printk(KERN_INFO "an RBV\n");
 142         } else if (oss_present) {
 143                 printk(KERN_INFO "an OSS\n");
 144         } else {
 145                 printk(KERN_INFO "a 6522 or clone\n");
 146         }
 147
 148 #ifdef DEBUG_VIA
 149         via_debug_dump();
 150 #endif
 151
 152         /*
 153          * Shut down all IRQ sources, reset the timers, and
 154          * kill the timer latch on VIA1.
 155          */
 156
 157         via1[vIER] = 0x7F;
 158         via1[vIFR] = 0x7F;
 159         via1[vT1LL] = 0;
 160         via1[vT1LH] = 0;
 161         via1[vT1CL] = 0;
 162         via1[vT1CH] = 0;
 163         via1[vT2CL] = 0;
 164         via1[vT2CH] = 0;
 165         via1[vACR] &= 0x3F;
 166
 167         /*
 168          * SE/30: disable video IRQ
 169          * XXX: testing for SE/30 VBL
 170          */
 171
 172         if (macintosh_config->ident == MAC_MODEL_SE30) {
 173                 via1[vDirB] |= 0x40;
 174                 via1[vBufB] |= 0x40;
 175         }
 176
 177         /*
 178          * Set the RTC bits to a known state: all lines to outputs and
 179          * RTC disabled (yes that's 0 to enable and 1 to disable).
 180          */
 181
 182         via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
 183         via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
 184
 185         /* Everything below this point is VIA2/RBV only... */
 186
 187         if (oss_present) return;
 188
 189 #if 1
 190         /* Some machines support an alternate IRQ mapping that spreads  */
 191         /* Ethernet and Sound out to their own autolevel IRQs and moves */
 192         /* VIA1 to level 6. A/UX uses this mapping and we do too.  Note */
 193         /* that the IIfx emulates this alternate mapping using the OSS. */
 194
 195         switch(macintosh_config->ident) {
 196                 case MAC_MODEL_C610:
 197                 case MAC_MODEL_Q610:
 198                 case MAC_MODEL_C650:
 199                 case MAC_MODEL_Q650:
 200                 case MAC_MODEL_Q700:
 201                 case MAC_MODEL_Q800:
 202                 case MAC_MODEL_Q900:
 203                 case MAC_MODEL_Q950:
 204                         via_alt_mapping = 1;
 205                         via1[vDirB] |= 0x40;
 206                         via1[vBufB] &= ~0x40;
 207                         break;
 208                 default:
 209                         via_alt_mapping = 0;
 210                         break;
 211         }
 212 #else
 213         via_alt_mapping = 0;
 214 #endif
 215
 216         /*
 217          * Now initialize VIA2. For RBV we just kill all interrupts;
 218          * for a regular VIA we also reset the timers and stuff.
 219          */
 220
 221         via2[gIER] = 0x7F;
 222         via2[gIFR] = 0x7F | rbv_clear;
 223         if (!rbv_present) {
 224                 via2[vT1LL] = 0;
 225                 via2[vT1LH] = 0;
 226                 via2[vT1CL] = 0;
 227                 via2[vT1CH] = 0;
 228                 via2[vT2CL] = 0;
 229                 via2[vT2CH] = 0;
 230                 via2[vACR] &= 0x3F;
 231         }
 232 }
 233
 234 /*
 235  * Start the 100 Hz clock
 236  */
 237
 238 void __init via_init_clock(irq_handler_t func)
 239 {
 240         via1[vACR] |= 0x40;
 241         via1[vT1LL] = MAC_CLOCK_LOW;
 242         via1[vT1LH] = MAC_CLOCK_HIGH;
 243         via1[vT1CL] = MAC_CLOCK_LOW;
 244         via1[vT1CH] = MAC_CLOCK_HIGH;
 245
 246         request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
 247 }
 248
 249 /*
 250  * Register the interrupt dispatchers for VIA or RBV machines only.
 251  */
 252
 253 void __init via_register_interrupts(void)
 254 {
 255         if (via_alt_mapping) {
 256                 request_irq(IRQ_AUTO_1, via1_irq,
 257                                 IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
 258                                 (void *) via1);
 259                 request_irq(IRQ_AUTO_6, via1_irq,
 260                                 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
 261                                 (void *) via1);
 262         } else {
 263                 request_irq(IRQ_AUTO_1, via1_irq,
 264                                 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
 265                                 (void *) via1);
 266         }
 267         request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 268                         "via2", (void *) via2);
 269         if (!psc_present) {
 270                 request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
 271                                 "scc", mac_scc_dispatch);
 272         }
 273         request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
 274                         "nubus", (void *) via2);
 275 }
 276
 277 /*
 278  * Debugging dump, used in various places to see what's going on.
 279  */
 280
 281 void via_debug_dump(void)
 282 {
 283         printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 284                 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
 285         printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 286                 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
 287         if (oss_present) {
 288                 printk(KERN_DEBUG "VIA2: <OSS>\n");
 289         } else if (rbv_present) {
 290                 printk(KERN_DEBUG "VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
 291                         (uint) via2[rIFR], (uint) via2[rIER]);
 292                 printk(KERN_DEBUG "      SIFR = 0x%02X SIER = 0x%02X\n",
 293                         (uint) via2[rSIFR], (uint) via2[rSIER]);
 294         } else {
 295                 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
 296                         (uint) via2[vDirA], (uint) via2[vDirB],
 297                         (uint) via2[vACR]);
 298                 printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
 299                         (uint) via2[vPCR],
 300                         (uint) via2[vIFR], (uint) via2[vIER]);
 301         }
 302 }
 303
 304 /*
 305  * This is always executed with interrupts disabled.
 306  *
 307  * TBI: get time offset between scheduling timer ticks
 308  */
 309
 310 unsigned long mac_gettimeoffset (void)
 311 {
 312         unsigned long ticks, offset = 0;
 313
 314         /* read VIA1 timer 2 current value */
 315         ticks = via1[vT1CL] | (via1[vT1CH] << 8);
 316         /* The probability of underflow is less than 2% */
 317         if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
 318                 /* Check for pending timer interrupt in VIA1 IFR */
 319                 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
 320
 321         ticks = MAC_CLOCK_TICK - ticks;
 322         ticks = ticks * 10000L / MAC_CLOCK_TICK;
 323
 324         return ticks + offset;
 325 }
 326
 327 /*
 328  * Flush the L2 cache on Macs that have it by flipping
 329  * the system into 24-bit mode for an instant.
 330  */
 331
 332 void via_flush_cache(void)
 333 {
 334         via2[gBufB] &= ~VIA2B_vMode32;
 335         via2[gBufB] |= VIA2B_vMode32;
 336 }
 337
 338 /*
 339  * Return the status of the L2 cache on a IIci
 340  */
 341
 342 int via_get_cache_disable(void)
 343 {
 344         /* Safeguard against being called accidentally */
 345         if (!via2) {
 346                 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
 347                 return 1;
 348         }
 349
 350         return (int) via2[gBufB] & VIA2B_vCDis;
 351 }
 352
 353 /*
 354  * Initialize VIA2 for Nubus access
 355  */
 356
 357 void __init via_nubus_init(void)
 358 {
 359         /* don't set nubus_active = 0 here, it kills the Baboon */
 360         /* interrupt that we've already registered.             */
 361
 362         /* unlock nubus transactions */
 363
 364         if (!rbv_present) {
 365                 /* set the line to be an output on non-RBV machines */
 366                 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 367                    (macintosh_config->adb_type != MAC_ADB_PB2)) {
 368                         via2[vDirB] |= 0x02;
 369                 }
 370         }
 371
 372         /* this seems to be an ADB bit on PMU machines */
 373         /* according to MkLinux.  -- jmt               */
 374
 375         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 376             (macintosh_config->adb_type != MAC_ADB_PB2)) {
 377                 via2[gBufB] |= 0x02;
 378         }
 379
 380         /* disable nubus slot interrupts. */
 381         if (rbv_present) {
 382                 via2[rSIER] = 0x7F;
 383                 via2[rSIER] = nubus_active | 0x80;
 384         } else {
 385                 /* These are ADB bits on PMU */
 386                 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 387                    (macintosh_config->adb_type != MAC_ADB_PB2)) {
 388                         switch(macintosh_config->ident)
 389                         {
 390                                 case MAC_MODEL_II:
 391                                 case MAC_MODEL_IIX:
 392                                 case MAC_MODEL_IICX:
 393                                 case MAC_MODEL_SE30:
 394                                         via2[vBufA] |= 0x3F;
 395                                         via2[vDirA] = ~nubus_active | 0xc0;
 396                                         break;
 397                                 default:
 398                                         via2[vBufA] = 0xFF;
 399                                         via2[vDirA] = ~nubus_active;
 400                         }
 401                 }
 402         }
 403 }
 404
 405 /*
 406  * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
 407  * via6522.c :-), disable/pending masks added.
 408  *
 409  * The new interrupt architecture in macints.c takes care of a lot of the
 410  * gruntwork for us, including tallying the interrupts and calling the
 411  * handlers on the linked list. All we need to do here is basically generate
 412  * the machspec interrupt number after clearing the interrupt.
 413  */
 414
 415 irqreturn_t via1_irq(int irq, void *dev_id)
 416 {
 417         int irq_bit, i;
 418         unsigned char events, mask;
 419
 420         mask = via1[vIER] & 0x7F;
 421         if (!(events = via1[vIFR] & mask))
 422                 return IRQ_NONE;
 423
 424         for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
 425                 if (events & irq_bit) {
 426                         via1[vIER] = irq_bit;
 427                         m68k_handle_int(VIA1_SOURCE_BASE + i);
 428                         via1[vIFR] = irq_bit;
 429                         via1[vIER] = irq_bit | 0x80;
 430                 }
 431
 432 #if 0 /* freakin' pmu is doing weird stuff */
 433         if (!oss_present) {
 434                 /* This (still) seems to be necessary to get IDE
 435                    working.  However, if you enable VBL interrupts,
 436                    you're screwed... */
 437                 /* FIXME: should we check the SLOTIRQ bit before
 438                    pulling this stunt? */
 439                 /* No, it won't be set. that's why we're doing this. */
 440                 via_irq_disable(IRQ_MAC_NUBUS);
 441                 via_irq_clear(IRQ_MAC_NUBUS);
 442                 m68k_handle_int(IRQ_MAC_NUBUS);
 443                 via_irq_enable(IRQ_MAC_NUBUS);
 444         }
 445 #endif
 446         return IRQ_HANDLED;
 447 }
 448
 449 irqreturn_t via2_irq(int irq, void *dev_id)
 450 {
 451         int irq_bit, i;
 452         unsigned char events, mask;
 453
 454         mask = via2[gIER] & 0x7F;
 455         if (!(events = via2[gIFR] & mask))
 456                 return IRQ_NONE;
 457
 458         for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
 459                 if (events & irq_bit) {
 460                         via2[gIER] = irq_bit;
 461                         via2[gIFR] = irq_bit | rbv_clear;
 462                         m68k_handle_int(VIA2_SOURCE_BASE + i);
 463                         via2[gIER] = irq_bit | 0x80;
 464                 }
 465         return IRQ_HANDLED;
 466 }
 467
 468 /*
 469  * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
 470  * VIA2 dispatcher as a fast interrupt handler.
 471  */
 472
 473 irqreturn_t via_nubus_irq(int irq, void *dev_id)
 474 {
 475         int irq_bit, i;
 476         unsigned char events;
 477
 478         if (!(events = ~via2[gBufA] & nubus_active))
 479                 return IRQ_NONE;
 480
 481         for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1) {
 482                 if (events & irq_bit) {
 483                         via_irq_disable(NUBUS_SOURCE_BASE + i);
 484                         m68k_handle_int(NUBUS_SOURCE_BASE + i);
 485                         via_irq_enable(NUBUS_SOURCE_BASE + i);
 486                 }
 487         }
 488         return IRQ_HANDLED;
 489 }
 490
 491 void via_irq_enable(int irq) {
 492         int irq_src     = IRQ_SRC(irq);
 493         int irq_idx     = IRQ_IDX(irq);
 494         int irq_bit     = 1 << irq_idx;
 495
 496 #ifdef DEBUG_IRQUSE
 497         printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
 498 #endif
 499
 500         if (irq_src == 1) {
 501                 via1[vIER] = irq_bit | 0x80;
 502         } else if (irq_src == 2) {
 503                 /*
 504                  * Set vPCR for SCSI interrupts (but not on RBV)
 505                  */
 506                 if ((irq_idx == 0) && !rbv_present) {
 507                         if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
 508                                 /* CB2 (IRQ) indep. input, positive edge */
 509                                 /* CA2 (DRQ) indep. input, positive edge */
 510                                 via2[vPCR] = 0x66;
 511                         } else {
 512                                 /* CB2 (IRQ) indep. input, negative edge */
 513                                 /* CA2 (DRQ) indep. input, negative edge */
 514                                 via2[vPCR] = 0x22;
 515                         }
 516                 }
 517                 via2[gIER] = irq_bit | 0x80;
 518         } else if (irq_src == 7) {
 519                 nubus_active |= irq_bit;
 520                 if (rbv_present) {
 521                         /* enable the slot interrupt. SIER works like IER. */
 522                         via2[rSIER] = IER_SET_BIT(irq_idx);
 523                 } else {
 524                         /* Make sure the bit is an input, to enable the irq */
 525                         /* But not on PowerBooks, that's ADB... */
 526                         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 527                            (macintosh_config->adb_type != MAC_ADB_PB2)) {
 528                                 switch(macintosh_config->ident)
 529                                 {
 530                                         case MAC_MODEL_II:
 531                                         case MAC_MODEL_IIX:
 532                                         case MAC_MODEL_IICX:
 533                                         case MAC_MODEL_SE30:
 534                                                 via2[vDirA] &= (~irq_bit | 0xc0);
 535                                                 break;
 536                                         default:
 537                                                 via2[vDirA] &= ~irq_bit;
 538                                 }
 539                         }
 540                 }
 541         }
 542 }
 543
 544 void via_irq_disable(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 #ifdef DEBUG_IRQUSE
 550         printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
 551 #endif
 552
 553         if (irq_src == 1) {
 554                 via1[vIER] = irq_bit;
 555         } else if (irq_src == 2) {
 556                 via2[gIER] = irq_bit;
 557         } else if (irq_src == 7) {
 558                 if (rbv_present) {
 559                         /* disable the slot interrupt.  SIER works like IER. */
 560                         via2[rSIER] = IER_CLR_BIT(irq_idx);
 561                 } else {
 562                         /* disable the nubus irq by changing dir to output */
 563                         /* except on PMU */
 564                         if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
 565                            (macintosh_config->adb_type != MAC_ADB_PB2)) {
 566                                 via2[vDirA] |= irq_bit;
 567                         }
 568                 }
 569                 nubus_active &= ~irq_bit;
 570         }
 571 }
 572
 573 void via_irq_clear(int irq) {
 574         int irq_src     = IRQ_SRC(irq);
 575         int irq_idx     = IRQ_IDX(irq);
 576         int irq_bit     = 1 << irq_idx;
 577
 578         if (irq_src == 1) {
 579                 via1[vIFR] = irq_bit;
 580         } else if (irq_src == 2) {
 581                 via2[gIFR] = irq_bit | rbv_clear;
 582         } else if (irq_src == 7) {
 583                 /* FIXME: hmm.. */
 584         }
 585 }
 586
 587 /*
 588  * Returns nonzero if an interrupt is pending on the given
 589  * VIA/IRQ combination.
 590  */
 591
 592 int via_irq_pending(int irq)
 593 {
 594         int irq_src     = IRQ_SRC(irq);
 595         int irq_idx     = IRQ_IDX(irq);
 596         int irq_bit     = 1 << irq_idx;
 597
 598         if (irq_src == 1) {
 599                 return via1[vIFR] & irq_bit;
 600         } else if (irq_src == 2) {
 601                 return via2[gIFR] & irq_bit;
 602         } else if (irq_src == 7) {
 603                 return ~via2[gBufA] & irq_bit;
 604         }
 605         return 0;
 606 }