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 relevant 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(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(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 static void via_nubus_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 if (irq_src == 1) { 554 via1[vIER] = IER_SET_BIT(irq_idx); 555 } else if (irq_src == 2) { 556 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0) 557 via2[gIER] = IER_SET_BIT(irq_idx); 558 } else if (irq_src == 7) { 559 switch (macintosh_config->via_type) { 560 case MAC_VIA_II: 561 case MAC_VIA_QUADRA: 562 nubus_disabled &= ~(1 << irq_idx); 563 /* Enable the CA1 interrupt when no slot is disabled. */ 564 if (!nubus_disabled) 565 via2[gIER] = IER_SET_BIT(1); 566 break; 567 case MAC_VIA_IICI: 568 /* On RBV, enable the slot interrupt. 569 * SIER works like IER. 570 */ 571 via2[rSIER] = IER_SET_BIT(irq_idx); 572 break; 573 } 574 } 575 } 576 577 void via_irq_disable(int irq) { 578 int irq_src = IRQ_SRC(irq); 579 int irq_idx = IRQ_IDX(irq); 580 581 if (irq_src == 1) { 582 via1[vIER] = IER_CLR_BIT(irq_idx); 583 } else if (irq_src == 2) { 584 via2[gIER] = IER_CLR_BIT(irq_idx); 585 } else if (irq_src == 7) { 586 switch (macintosh_config->via_type) { 587 case MAC_VIA_II: 588 case MAC_VIA_QUADRA: 589 nubus_disabled |= 1 << irq_idx; 590 if (nubus_disabled) 591 via2[gIER] = IER_CLR_BIT(1); 592 break; 593 case MAC_VIA_IICI: 594 via2[rSIER] = IER_CLR_BIT(irq_idx); 595 break; 596 } 597 } 598 } 599 600 void via1_set_head(int head) 601 { 602 if (head == 0) 603 via1[vBufA] &= ~VIA1A_vHeadSel; 604 else 605 via1[vBufA] |= VIA1A_vHeadSel; 606 } 607 EXPORT_SYMBOL(via1_set_head); 608 609 int via2_scsi_drq_pending(void) 610 { 611 return via2[gIFR] & (1 << IRQ_IDX(IRQ_MAC_SCSIDRQ)); 612 } 613 EXPORT_SYMBOL(via2_scsi_drq_pending); 614