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/ide.h> 31 #include <linux/module.h> 32 33 #include <asm/bootinfo.h> 34 #include <asm/macintosh.h> 35 #include <asm/macints.h> 36 #include <asm/machw.h> 37 #include <asm/mac_via.h> 38 #include <asm/mac_psc.h> 39 40 volatile __u8 *via1, *via2; 41 #if 0 42 /* See note in mac_via.h about how this is possibly not useful */ 43 volatile long *via_memory_bogon=(long *)&via_memory_bogon; 44 #endif 45 int rbv_present; 46 int via_alt_mapping; 47 EXPORT_SYMBOL(via_alt_mapping); 48 __u8 rbv_clear; 49 50 /* 51 * Globals for accessing the VIA chip registers without having to 52 * check if we're hitting a real VIA or an RBV. Normally you could 53 * just hit the combined register (ie, vIER|rIER) but that seems to 54 * break on AV Macs...probably because they actually decode more than 55 * eight address bits. Why can't Apple engineers at least be 56 * _consistently_ lazy? - 1999-05-21 (jmt) 57 */ 58 59 static int gIER,gIFR,gBufA,gBufB; 60 61 /* 62 * Timer defs. 63 */ 64 65 #define TICK_SIZE 10000 66 #define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */ 67 #define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF) 68 #define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8) 69 70 /* To disable a NuBus slot on Quadras we make the slot IRQ lines outputs, set 71 * high. On RBV we just use the slot interrupt enable register. On Macs with 72 * genuine VIA chips we must use nubus_disabled to keep track of disabled slot 73 * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1 74 * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt. 75 * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble, 76 * because closing one of those drivers can mask all of the NuBus interrupts. 77 * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's 78 * possible to get interrupts from cards that MacOS or the ROM has configured 79 * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and 80 * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS. 81 */ 82 static u8 nubus_disabled; 83 84 void via_debug_dump(void); 85 irqreturn_t via1_irq(int, void *); 86 irqreturn_t via2_irq(int, void *); 87 irqreturn_t via_nubus_irq(int, void *); 88 void via_irq_enable(int irq); 89 void via_irq_disable(int irq); 90 void via_irq_clear(int irq); 91 92 extern irqreturn_t mac_scc_dispatch(int, void *); 93 extern int oss_present; 94 95 /* 96 * Initialize the VIAs 97 * 98 * First we figure out where they actually _are_ as well as what type of 99 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.) 100 * Then we pretty much clear them out and disable all IRQ sources. 101 * 102 * Note: the OSS is actually "detected" here and not in oss_init(). It just 103 * seems more logical to do it here since via_init() needs to know 104 * these things anyways. 105 */ 106 107 void __init via_init(void) 108 { 109 switch(macintosh_config->via_type) { 110 111 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */ 112 113 case MAC_VIA_IIci: 114 via1 = (void *) VIA1_BASE; 115 if (macintosh_config->ident == MAC_MODEL_IIFX) { 116 via2 = NULL; 117 rbv_present = 0; 118 oss_present = 1; 119 } else { 120 via2 = (void *) RBV_BASE; 121 rbv_present = 1; 122 oss_present = 0; 123 } 124 if (macintosh_config->ident == MAC_MODEL_LCIII) { 125 rbv_clear = 0x00; 126 } else { 127 /* on most RBVs (& unlike the VIAs), you */ 128 /* need to set bit 7 when you write to IFR */ 129 /* in order for your clear to occur. */ 130 rbv_clear = 0x80; 131 } 132 gIER = rIER; 133 gIFR = rIFR; 134 gBufA = rSIFR; 135 gBufB = rBufB; 136 break; 137 138 /* Quadra and early MacIIs agree on the VIA locations */ 139 140 case MAC_VIA_QUADRA: 141 case MAC_VIA_II: 142 via1 = (void *) VIA1_BASE; 143 via2 = (void *) VIA2_BASE; 144 rbv_present = 0; 145 oss_present = 0; 146 rbv_clear = 0x00; 147 gIER = vIER; 148 gIFR = vIFR; 149 gBufA = vBufA; 150 gBufB = vBufB; 151 break; 152 default: 153 panic("UNKNOWN VIA TYPE"); 154 } 155 156 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1); 157 158 printk(KERN_INFO "VIA2 at %p is ", via2); 159 if (rbv_present) { 160 printk("an RBV\n"); 161 } else if (oss_present) { 162 printk("an OSS\n"); 163 } else { 164 printk("a 6522 or clone\n"); 165 } 166 167 #ifdef DEBUG_VIA 168 via_debug_dump(); 169 #endif 170 171 /* 172 * Shut down all IRQ sources, reset the timers, and 173 * kill the timer latch on VIA1. 174 */ 175 176 via1[vIER] = 0x7F; 177 via1[vIFR] = 0x7F; 178 via1[vT1LL] = 0; 179 via1[vT1LH] = 0; 180 via1[vT1CL] = 0; 181 via1[vT1CH] = 0; 182 via1[vT2CL] = 0; 183 via1[vT2CH] = 0; 184 via1[vACR] &= 0x3F; 185 via1[vACR] &= ~0x03; /* disable port A & B latches */ 186 187 /* 188 * SE/30: disable video IRQ 189 * XXX: testing for SE/30 VBL 190 */ 191 192 if (macintosh_config->ident == MAC_MODEL_SE30) { 193 via1[vDirB] |= 0x40; 194 via1[vBufB] |= 0x40; 195 } 196 197 /* 198 * Set the RTC bits to a known state: all lines to outputs and 199 * RTC disabled (yes that's 0 to enable and 1 to disable). 200 */ 201 202 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData); 203 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk); 204 205 /* Everything below this point is VIA2/RBV only... */ 206 207 if (oss_present) return; 208 209 #if 1 210 /* Some machines support an alternate IRQ mapping that spreads */ 211 /* Ethernet and Sound out to their own autolevel IRQs and moves */ 212 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */ 213 /* that the IIfx emulates this alternate mapping using the OSS. */ 214 215 switch(macintosh_config->ident) { 216 case MAC_MODEL_P475: 217 case MAC_MODEL_P475F: 218 case MAC_MODEL_P575: 219 case MAC_MODEL_Q605: 220 case MAC_MODEL_Q605_ACC: 221 case MAC_MODEL_C610: 222 case MAC_MODEL_Q610: 223 case MAC_MODEL_Q630: 224 case MAC_MODEL_C650: 225 case MAC_MODEL_Q650: 226 case MAC_MODEL_Q700: 227 case MAC_MODEL_Q800: 228 case MAC_MODEL_Q900: 229 case MAC_MODEL_Q950: 230 via_alt_mapping = 1; 231 via1[vDirB] |= 0x40; 232 via1[vBufB] &= ~0x40; 233 break; 234 default: 235 via_alt_mapping = 0; 236 break; 237 } 238 #else 239 via_alt_mapping = 0; 240 #endif 241 242 /* 243 * Now initialize VIA2. For RBV we just kill all interrupts; 244 * for a regular VIA we also reset the timers and stuff. 245 */ 246 247 via2[gIER] = 0x7F; 248 via2[gIFR] = 0x7F | rbv_clear; 249 if (!rbv_present) { 250 via2[vT1LL] = 0; 251 via2[vT1LH] = 0; 252 via2[vT1CL] = 0; 253 via2[vT1CH] = 0; 254 via2[vT2CL] = 0; 255 via2[vT2CH] = 0; 256 via2[vACR] &= 0x3F; 257 via2[vACR] &= ~0x03; /* disable port A & B latches */ 258 } 259 260 /* 261 * Set vPCR for SCSI interrupts (but not on RBV) 262 */ 263 if (!rbv_present) { 264 if (macintosh_config->scsi_type == MAC_SCSI_OLD) { 265 /* CB2 (IRQ) indep. input, positive edge */ 266 /* CA2 (DRQ) indep. input, positive edge */ 267 via2[vPCR] = 0x66; 268 } else { 269 /* CB2 (IRQ) indep. input, negative edge */ 270 /* CA2 (DRQ) indep. input, negative edge */ 271 via2[vPCR] = 0x22; 272 } 273 } 274 } 275 276 /* 277 * Start the 100 Hz clock 278 */ 279 280 void __init via_init_clock(irq_handler_t func) 281 { 282 via1[vACR] |= 0x40; 283 via1[vT1LL] = MAC_CLOCK_LOW; 284 via1[vT1LH] = MAC_CLOCK_HIGH; 285 via1[vT1CL] = MAC_CLOCK_LOW; 286 via1[vT1CH] = MAC_CLOCK_HIGH; 287 288 request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func); 289 } 290 291 /* 292 * Register the interrupt dispatchers for VIA or RBV machines only. 293 */ 294 295 void __init via_register_interrupts(void) 296 { 297 if (via_alt_mapping) { 298 request_irq(IRQ_AUTO_1, via1_irq, 299 IRQ_FLG_LOCK|IRQ_FLG_FAST, "software", 300 (void *) via1); 301 request_irq(IRQ_AUTO_6, via1_irq, 302 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1", 303 (void *) via1); 304 } else { 305 request_irq(IRQ_AUTO_1, via1_irq, 306 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1", 307 (void *) via1); 308 } 309 request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST, 310 "via2", (void *) via2); 311 if (!psc_present) { 312 request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK, 313 "scc", mac_scc_dispatch); 314 } 315 request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST, 316 "nubus", (void *) via2); 317 } 318 319 /* 320 * Debugging dump, used in various places to see what's going on. 321 */ 322 323 void via_debug_dump(void) 324 { 325 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n", 326 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]); 327 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n", 328 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]); 329 if (oss_present) { 330 printk(KERN_DEBUG "VIA2: <OSS>\n"); 331 } else if (rbv_present) { 332 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n", 333 (uint) via2[rIFR], (uint) via2[rIER]); 334 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n", 335 (uint) via2[rSIFR], (uint) via2[rSIER]); 336 } else { 337 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n", 338 (uint) via2[vDirA], (uint) via2[vDirB], 339 (uint) via2[vACR]); 340 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n", 341 (uint) via2[vPCR], 342 (uint) via2[vIFR], (uint) via2[vIER]); 343 } 344 } 345 346 /* 347 * This is always executed with interrupts disabled. 348 * 349 * TBI: get time offset between scheduling timer ticks 350 */ 351 352 unsigned long mac_gettimeoffset (void) 353 { 354 unsigned long ticks, offset = 0; 355 356 /* read VIA1 timer 2 current value */ 357 ticks = via1[vT1CL] | (via1[vT1CH] << 8); 358 /* The probability of underflow is less than 2% */ 359 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50) 360 /* Check for pending timer interrupt in VIA1 IFR */ 361 if (via1[vIFR] & 0x40) offset = TICK_SIZE; 362 363 ticks = MAC_CLOCK_TICK - ticks; 364 ticks = ticks * 10000L / MAC_CLOCK_TICK; 365 366 return ticks + offset; 367 } 368 369 /* 370 * Flush the L2 cache on Macs that have it by flipping 371 * the system into 24-bit mode for an instant. 372 */ 373 374 void via_flush_cache(void) 375 { 376 via2[gBufB] &= ~VIA2B_vMode32; 377 via2[gBufB] |= VIA2B_vMode32; 378 } 379 380 /* 381 * Return the status of the L2 cache on a IIci 382 */ 383 384 int via_get_cache_disable(void) 385 { 386 /* Safeguard against being called accidentally */ 387 if (!via2) { 388 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n"); 389 return 1; 390 } 391 392 return (int) via2[gBufB] & VIA2B_vCDis; 393 } 394 395 /* 396 * Initialize VIA2 for Nubus access 397 */ 398 399 void __init via_nubus_init(void) 400 { 401 /* unlock nubus transactions */ 402 403 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 404 (macintosh_config->adb_type != MAC_ADB_PB2)) { 405 /* set the line to be an output on non-RBV machines */ 406 if (!rbv_present) 407 via2[vDirB] |= 0x02; 408 409 /* this seems to be an ADB bit on PMU machines */ 410 /* according to MkLinux. -- jmt */ 411 via2[gBufB] |= 0x02; 412 } 413 414 /* Disable all the slot interrupts (where possible). */ 415 416 switch (macintosh_config->via_type) { 417 case MAC_VIA_II: 418 /* Just make the port A lines inputs. */ 419 switch(macintosh_config->ident) { 420 case MAC_MODEL_II: 421 case MAC_MODEL_IIX: 422 case MAC_MODEL_IICX: 423 case MAC_MODEL_SE30: 424 /* The top two bits are RAM size outputs. */ 425 via2[vDirA] &= 0xC0; 426 break; 427 default: 428 via2[vDirA] &= 0x80; 429 } 430 break; 431 case MAC_VIA_IIci: 432 /* RBV. Disable all the slot interrupts. SIER works like IER. */ 433 via2[rSIER] = 0x7F; 434 break; 435 case MAC_VIA_QUADRA: 436 /* Disable the inactive slot interrupts by making those lines outputs. */ 437 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 438 (macintosh_config->adb_type != MAC_ADB_PB2)) { 439 via2[vBufA] |= 0x7F; 440 via2[vDirA] |= 0x7F; 441 } 442 break; 443 } 444 } 445 446 /* 447 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's 448 * via6522.c :-), disable/pending masks added. 449 */ 450 451 irqreturn_t via1_irq(int irq, void *dev_id) 452 { 453 int irq_num; 454 unsigned char irq_bit, events; 455 456 events = via1[vIFR] & via1[vIER] & 0x7F; 457 if (!events) 458 return IRQ_NONE; 459 460 irq_num = VIA1_SOURCE_BASE; 461 irq_bit = 1; 462 do { 463 if (events & irq_bit) { 464 via1[vIFR] = irq_bit; 465 m68k_handle_int(irq_num); 466 } 467 ++irq_num; 468 irq_bit <<= 1; 469 } while (events >= irq_bit); 470 471 #if 0 /* freakin' pmu is doing weird stuff */ 472 if (!oss_present) { 473 /* This (still) seems to be necessary to get IDE 474 working. However, if you enable VBL interrupts, 475 you're screwed... */ 476 /* FIXME: should we check the SLOTIRQ bit before 477 pulling this stunt? */ 478 /* No, it won't be set. that's why we're doing this. */ 479 via_irq_disable(IRQ_MAC_NUBUS); 480 via_irq_clear(IRQ_MAC_NUBUS); 481 m68k_handle_int(IRQ_MAC_NUBUS); 482 via_irq_enable(IRQ_MAC_NUBUS); 483 } 484 #endif 485 return IRQ_HANDLED; 486 } 487 488 irqreturn_t via2_irq(int irq, void *dev_id) 489 { 490 int irq_num; 491 unsigned char irq_bit, events; 492 493 events = via2[gIFR] & via2[gIER] & 0x7F; 494 if (!events) 495 return IRQ_NONE; 496 497 irq_num = VIA2_SOURCE_BASE; 498 irq_bit = 1; 499 do { 500 if (events & irq_bit) { 501 via2[gIFR] = irq_bit | rbv_clear; 502 m68k_handle_int(irq_num); 503 } 504 ++irq_num; 505 irq_bit <<= 1; 506 } while (events >= irq_bit); 507 return IRQ_HANDLED; 508 } 509 510 /* 511 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the 512 * VIA2 dispatcher as a fast interrupt handler. 513 */ 514 515 irqreturn_t via_nubus_irq(int irq, void *dev_id) 516 { 517 int slot_irq; 518 unsigned char slot_bit, events; 519 520 events = ~via2[gBufA] & 0x7F; 521 if (rbv_present) 522 events &= via2[rSIER]; 523 else 524 events &= ~via2[vDirA]; 525 if (!events) 526 return IRQ_NONE; 527 528 do { 529 slot_irq = IRQ_NUBUS_F; 530 slot_bit = 0x40; 531 do { 532 if (events & slot_bit) { 533 events &= ~slot_bit; 534 m68k_handle_int(slot_irq); 535 } 536 --slot_irq; 537 slot_bit >>= 1; 538 } while (events); 539 540 /* clear the CA1 interrupt and make certain there's no more. */ 541 via2[gIFR] = 0x02 | rbv_clear; 542 events = ~via2[gBufA] & 0x7F; 543 if (rbv_present) 544 events &= via2[rSIER]; 545 else 546 events &= ~via2[vDirA]; 547 } while (events); 548 return IRQ_HANDLED; 549 } 550 551 void via_irq_enable(int irq) { 552 int irq_src = IRQ_SRC(irq); 553 int irq_idx = IRQ_IDX(irq); 554 555 #ifdef DEBUG_IRQUSE 556 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq); 557 #endif 558 559 if (irq_src == 1) { 560 via1[vIER] = IER_SET_BIT(irq_idx); 561 } else if (irq_src == 2) { 562 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0) 563 via2[gIER] = IER_SET_BIT(irq_idx); 564 } else if (irq_src == 7) { 565 switch (macintosh_config->via_type) { 566 case MAC_VIA_II: 567 nubus_disabled &= ~(1 << irq_idx); 568 /* Enable the CA1 interrupt when no slot is disabled. */ 569 if (!nubus_disabled) 570 via2[gIER] = IER_SET_BIT(1); 571 break; 572 case MAC_VIA_IIci: 573 /* On RBV, enable the slot interrupt. 574 * SIER works like IER. 575 */ 576 via2[rSIER] = IER_SET_BIT(irq_idx); 577 break; 578 case MAC_VIA_QUADRA: 579 /* Make the port A line an input to enable the slot irq. 580 * But not on PowerBooks, that's ADB. 581 */ 582 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 583 (macintosh_config->adb_type != MAC_ADB_PB2)) 584 via2[vDirA] &= ~(1 << irq_idx); 585 break; 586 } 587 } 588 } 589 590 void via_irq_disable(int irq) { 591 int irq_src = IRQ_SRC(irq); 592 int irq_idx = IRQ_IDX(irq); 593 594 #ifdef DEBUG_IRQUSE 595 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq); 596 #endif 597 598 if (irq_src == 1) { 599 via1[vIER] = IER_CLR_BIT(irq_idx); 600 } else if (irq_src == 2) { 601 via2[gIER] = IER_CLR_BIT(irq_idx); 602 } else if (irq_src == 7) { 603 switch (macintosh_config->via_type) { 604 case MAC_VIA_II: 605 nubus_disabled |= 1 << irq_idx; 606 if (nubus_disabled) 607 via2[gIER] = IER_CLR_BIT(1); 608 break; 609 case MAC_VIA_IIci: 610 via2[rSIER] = IER_CLR_BIT(irq_idx); 611 break; 612 case MAC_VIA_QUADRA: 613 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 614 (macintosh_config->adb_type != MAC_ADB_PB2)) 615 via2[vDirA] |= 1 << irq_idx; 616 break; 617 } 618 } 619 } 620 621 void via_irq_clear(int irq) { 622 int irq_src = IRQ_SRC(irq); 623 int irq_idx = IRQ_IDX(irq); 624 int irq_bit = 1 << irq_idx; 625 626 if (irq_src == 1) { 627 via1[vIFR] = irq_bit; 628 } else if (irq_src == 2) { 629 via2[gIFR] = irq_bit | rbv_clear; 630 } else if (irq_src == 7) { 631 /* FIXME: There is no way to clear an individual nubus slot 632 * IRQ flag, other than getting the device to do it. 633 */ 634 } 635 } 636 637 /* 638 * Returns nonzero if an interrupt is pending on the given 639 * VIA/IRQ combination. 640 */ 641 642 int via_irq_pending(int irq) 643 { 644 int irq_src = IRQ_SRC(irq); 645 int irq_idx = IRQ_IDX(irq); 646 int irq_bit = 1 << irq_idx; 647 648 if (irq_src == 1) { 649 return via1[vIFR] & irq_bit; 650 } else if (irq_src == 2) { 651 return via2[gIFR] & irq_bit; 652 } else if (irq_src == 7) { 653 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */ 654 return ~via2[gBufA] & irq_bit; 655 } 656 return 0; 657 } 658