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