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/bootinfo.h> 34 #include <asm/macintosh.h> 35 #include <asm/macints.h> 36 #include <asm/mac_via.h> 37 #include <asm/mac_psc.h> 38 #include <asm/mac_oss.h> 39 40 volatile __u8 *via1, *via2; 41 int rbv_present; 42 int via_alt_mapping; 43 EXPORT_SYMBOL(via_alt_mapping); 44 static __u8 rbv_clear; 45 46 /* 47 * Globals for accessing the VIA chip registers without having to 48 * check if we're hitting a real VIA or an RBV. Normally you could 49 * just hit the combined register (ie, vIER|rIER) but that seems to 50 * break on AV Macs...probably because they actually decode more than 51 * eight address bits. Why can't Apple engineers at least be 52 * _consistently_ lazy? - 1999-05-21 (jmt) 53 */ 54 55 static int gIER,gIFR,gBufA,gBufB; 56 57 /* 58 * Timer defs. 59 */ 60 61 #define TICK_SIZE 10000 62 #define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */ 63 #define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF) 64 #define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8) 65 66 /* To disable a NuBus slot on Quadras we make that slot IRQ line an output set 67 * high. On RBV we just use the slot interrupt enable register. On Macs with 68 * genuine VIA chips we must use nubus_disabled to keep track of disabled slot 69 * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1 70 * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt. 71 * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble, 72 * because closing one of those drivers can mask all of the NuBus interrupts. 73 * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's 74 * possible to get interrupts from cards that MacOS or the ROM has configured 75 * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and 76 * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS. 77 */ 78 static u8 nubus_disabled; 79 80 void via_debug_dump(void); 81 void via_irq_enable(int irq); 82 void via_irq_disable(int irq); 83 void via_irq_clear(int irq); 84 85 /* 86 * Initialize the VIAs 87 * 88 * First we figure out where they actually _are_ as well as what type of 89 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.) 90 * Then we pretty much clear them out and disable all IRQ sources. 91 * 92 * Note: the OSS is actually "detected" here and not in oss_init(). It just 93 * seems more logical to do it here since via_init() needs to know 94 * these things anyways. 95 */ 96 97 void __init via_init(void) 98 { 99 switch(macintosh_config->via_type) { 100 101 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */ 102 103 case MAC_VIA_IIci: 104 via1 = (void *) VIA1_BASE; 105 if (macintosh_config->ident == MAC_MODEL_IIFX) { 106 via2 = NULL; 107 rbv_present = 0; 108 oss_present = 1; 109 } else { 110 via2 = (void *) RBV_BASE; 111 rbv_present = 1; 112 oss_present = 0; 113 } 114 if (macintosh_config->ident == MAC_MODEL_LCIII) { 115 rbv_clear = 0x00; 116 } else { 117 /* on most RBVs (& unlike the VIAs), you */ 118 /* need to set bit 7 when you write to IFR */ 119 /* in order for your clear to occur. */ 120 rbv_clear = 0x80; 121 } 122 gIER = rIER; 123 gIFR = rIFR; 124 gBufA = rSIFR; 125 gBufB = rBufB; 126 break; 127 128 /* Quadra and early MacIIs agree on the VIA locations */ 129 130 case MAC_VIA_QUADRA: 131 case MAC_VIA_II: 132 via1 = (void *) VIA1_BASE; 133 via2 = (void *) VIA2_BASE; 134 rbv_present = 0; 135 oss_present = 0; 136 rbv_clear = 0x00; 137 gIER = vIER; 138 gIFR = vIFR; 139 gBufA = vBufA; 140 gBufB = vBufB; 141 break; 142 default: 143 panic("UNKNOWN VIA TYPE"); 144 } 145 146 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1); 147 148 printk(KERN_INFO "VIA2 at %p is ", via2); 149 if (rbv_present) { 150 printk("an RBV\n"); 151 } else if (oss_present) { 152 printk("an OSS\n"); 153 } else { 154 printk("a 6522 or clone\n"); 155 } 156 157 #ifdef DEBUG_VIA 158 via_debug_dump(); 159 #endif 160 161 /* 162 * Shut down all IRQ sources, reset the timers, and 163 * kill the timer latch on VIA1. 164 */ 165 166 via1[vIER] = 0x7F; 167 via1[vIFR] = 0x7F; 168 via1[vT1LL] = 0; 169 via1[vT1LH] = 0; 170 via1[vT1CL] = 0; 171 via1[vT1CH] = 0; 172 via1[vT2CL] = 0; 173 via1[vT2CH] = 0; 174 via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */ 175 via1[vACR] &= ~0x03; /* disable port A & B latches */ 176 177 /* 178 * SE/30: disable video IRQ 179 * XXX: testing for SE/30 VBL 180 */ 181 182 if (macintosh_config->ident == MAC_MODEL_SE30) { 183 via1[vDirB] |= 0x40; 184 via1[vBufB] |= 0x40; 185 } 186 187 /* 188 * Set the RTC bits to a known state: all lines to outputs and 189 * RTC disabled (yes that's 0 to enable and 1 to disable). 190 */ 191 192 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData); 193 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk); 194 195 /* Everything below this point is VIA2/RBV only... */ 196 197 if (oss_present) 198 return; 199 200 /* Some machines support an alternate IRQ mapping that spreads */ 201 /* Ethernet and Sound out to their own autolevel IRQs and moves */ 202 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */ 203 /* that the IIfx emulates this alternate mapping using the OSS. */ 204 205 via_alt_mapping = 0; 206 if (macintosh_config->via_type == MAC_VIA_QUADRA) 207 switch (macintosh_config->ident) { 208 case MAC_MODEL_C660: 209 case MAC_MODEL_Q840: 210 /* not applicable */ 211 break; 212 case MAC_MODEL_P588: 213 case MAC_MODEL_TV: 214 case MAC_MODEL_PB140: 215 case MAC_MODEL_PB145: 216 case MAC_MODEL_PB160: 217 case MAC_MODEL_PB165: 218 case MAC_MODEL_PB165C: 219 case MAC_MODEL_PB170: 220 case MAC_MODEL_PB180: 221 case MAC_MODEL_PB180C: 222 case MAC_MODEL_PB190: 223 case MAC_MODEL_PB520: 224 /* not yet tested */ 225 break; 226 default: 227 via_alt_mapping = 1; 228 via1[vDirB] |= 0x40; 229 via1[vBufB] &= ~0x40; 230 break; 231 } 232 233 /* 234 * Now initialize VIA2. For RBV we just kill all interrupts; 235 * for a regular VIA we also reset the timers and stuff. 236 */ 237 238 via2[gIER] = 0x7F; 239 via2[gIFR] = 0x7F | rbv_clear; 240 if (!rbv_present) { 241 via2[vT1LL] = 0; 242 via2[vT1LH] = 0; 243 via2[vT1CL] = 0; 244 via2[vT1CH] = 0; 245 via2[vT2CL] = 0; 246 via2[vT2CH] = 0; 247 via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */ 248 via2[vACR] &= ~0x03; /* disable port A & B latches */ 249 } 250 251 /* 252 * Set vPCR for control line interrupts (but not on RBV) 253 */ 254 if (!rbv_present) { 255 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ) 256 * are made negative edge triggered here. 257 */ 258 if (macintosh_config->scsi_type == MAC_SCSI_OLD) { 259 /* CB2 (IRQ) indep. input, positive edge */ 260 /* CA2 (DRQ) indep. input, positive edge */ 261 via2[vPCR] = 0x66; 262 } else { 263 /* CB2 (IRQ) indep. input, negative edge */ 264 /* CA2 (DRQ) indep. input, negative edge */ 265 via2[vPCR] = 0x22; 266 } 267 } 268 } 269 270 /* 271 * Start the 100 Hz clock 272 */ 273 274 void __init via_init_clock(irq_handler_t func) 275 { 276 via1[vACR] |= 0x40; 277 via1[vT1LL] = MAC_CLOCK_LOW; 278 via1[vT1LH] = MAC_CLOCK_HIGH; 279 via1[vT1CL] = MAC_CLOCK_LOW; 280 via1[vT1CH] = MAC_CLOCK_HIGH; 281 282 if (request_irq(IRQ_MAC_TIMER_1, func, 0, "timer", func)) 283 pr_err("Couldn't register %s interrupt\n", "timer"); 284 } 285 286 /* 287 * Debugging dump, used in various places to see what's going on. 288 */ 289 290 void via_debug_dump(void) 291 { 292 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n", 293 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]); 294 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n", 295 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]); 296 if (oss_present) { 297 printk(KERN_DEBUG "VIA2: <OSS>\n"); 298 } else if (rbv_present) { 299 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n", 300 (uint) via2[rIFR], (uint) via2[rIER]); 301 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n", 302 (uint) via2[rSIFR], (uint) via2[rSIER]); 303 } else { 304 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n", 305 (uint) via2[vDirA], (uint) via2[vDirB], 306 (uint) via2[vACR]); 307 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n", 308 (uint) via2[vPCR], 309 (uint) via2[vIFR], (uint) via2[vIER]); 310 } 311 } 312 313 /* 314 * This is always executed with interrupts disabled. 315 * 316 * TBI: get time offset between scheduling timer ticks 317 */ 318 319 unsigned long mac_gettimeoffset (void) 320 { 321 unsigned long ticks, offset = 0; 322 323 /* read VIA1 timer 2 current value */ 324 ticks = via1[vT1CL] | (via1[vT1CH] << 8); 325 /* The probability of underflow is less than 2% */ 326 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50) 327 /* Check for pending timer interrupt in VIA1 IFR */ 328 if (via1[vIFR] & 0x40) offset = TICK_SIZE; 329 330 ticks = MAC_CLOCK_TICK - ticks; 331 ticks = ticks * 10000L / MAC_CLOCK_TICK; 332 333 return ticks + offset; 334 } 335 336 /* 337 * Flush the L2 cache on Macs that have it by flipping 338 * the system into 24-bit mode for an instant. 339 */ 340 341 void via_flush_cache(void) 342 { 343 via2[gBufB] &= ~VIA2B_vMode32; 344 via2[gBufB] |= VIA2B_vMode32; 345 } 346 347 /* 348 * Return the status of the L2 cache on a IIci 349 */ 350 351 int via_get_cache_disable(void) 352 { 353 /* Safeguard against being called accidentally */ 354 if (!via2) { 355 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n"); 356 return 1; 357 } 358 359 return (int) via2[gBufB] & VIA2B_vCDis; 360 } 361 362 /* 363 * Initialize VIA2 for Nubus access 364 */ 365 366 void __init via_nubus_init(void) 367 { 368 /* unlock nubus transactions */ 369 370 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 371 (macintosh_config->adb_type != MAC_ADB_PB2)) { 372 /* set the line to be an output on non-RBV machines */ 373 if (!rbv_present) 374 via2[vDirB] |= 0x02; 375 376 /* this seems to be an ADB bit on PMU machines */ 377 /* according to MkLinux. -- jmt */ 378 via2[gBufB] |= 0x02; 379 } 380 381 /* Disable all the slot interrupts (where possible). */ 382 383 switch (macintosh_config->via_type) { 384 case MAC_VIA_II: 385 /* Just make the port A lines inputs. */ 386 switch(macintosh_config->ident) { 387 case MAC_MODEL_II: 388 case MAC_MODEL_IIX: 389 case MAC_MODEL_IICX: 390 case MAC_MODEL_SE30: 391 /* The top two bits are RAM size outputs. */ 392 via2[vDirA] &= 0xC0; 393 break; 394 default: 395 via2[vDirA] &= 0x80; 396 } 397 break; 398 case MAC_VIA_IIci: 399 /* RBV. Disable all the slot interrupts. SIER works like IER. */ 400 via2[rSIER] = 0x7F; 401 break; 402 case MAC_VIA_QUADRA: 403 /* Disable the inactive slot interrupts by making those lines outputs. */ 404 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 405 (macintosh_config->adb_type != MAC_ADB_PB2)) { 406 via2[vBufA] |= 0x7F; 407 via2[vDirA] |= 0x7F; 408 } 409 break; 410 } 411 } 412 413 /* 414 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's 415 * via6522.c :-), disable/pending masks added. 416 */ 417 418 void via1_irq(unsigned int irq, struct irq_desc *desc) 419 { 420 int irq_num; 421 unsigned char irq_bit, events; 422 423 events = via1[vIFR] & via1[vIER] & 0x7F; 424 if (!events) 425 return; 426 427 irq_num = VIA1_SOURCE_BASE; 428 irq_bit = 1; 429 do { 430 if (events & irq_bit) { 431 via1[vIFR] = irq_bit; 432 generic_handle_irq(irq_num); 433 } 434 ++irq_num; 435 irq_bit <<= 1; 436 } while (events >= irq_bit); 437 } 438 439 static void via2_irq(unsigned int irq, struct irq_desc *desc) 440 { 441 int irq_num; 442 unsigned char irq_bit, events; 443 444 events = via2[gIFR] & via2[gIER] & 0x7F; 445 if (!events) 446 return; 447 448 irq_num = VIA2_SOURCE_BASE; 449 irq_bit = 1; 450 do { 451 if (events & irq_bit) { 452 via2[gIFR] = irq_bit | rbv_clear; 453 generic_handle_irq(irq_num); 454 } 455 ++irq_num; 456 irq_bit <<= 1; 457 } while (events >= irq_bit); 458 } 459 460 /* 461 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the 462 * VIA2 dispatcher as a fast interrupt handler. 463 */ 464 465 void via_nubus_irq(unsigned int irq, struct irq_desc *desc) 466 { 467 int slot_irq; 468 unsigned char slot_bit, events; 469 470 events = ~via2[gBufA] & 0x7F; 471 if (rbv_present) 472 events &= via2[rSIER]; 473 else 474 events &= ~via2[vDirA]; 475 if (!events) 476 return; 477 478 do { 479 slot_irq = IRQ_NUBUS_F; 480 slot_bit = 0x40; 481 do { 482 if (events & slot_bit) { 483 events &= ~slot_bit; 484 generic_handle_irq(slot_irq); 485 } 486 --slot_irq; 487 slot_bit >>= 1; 488 } while (events); 489 490 /* clear the CA1 interrupt and make certain there's no more. */ 491 via2[gIFR] = 0x02 | rbv_clear; 492 events = ~via2[gBufA] & 0x7F; 493 if (rbv_present) 494 events &= via2[rSIER]; 495 else 496 events &= ~via2[vDirA]; 497 } while (events); 498 } 499 500 /* 501 * Register the interrupt dispatchers for VIA or RBV machines only. 502 */ 503 504 void __init via_register_interrupts(void) 505 { 506 if (via_alt_mapping) { 507 /* software interrupt */ 508 irq_set_chained_handler(IRQ_AUTO_1, via1_irq); 509 /* via1 interrupt */ 510 irq_set_chained_handler(IRQ_AUTO_6, via1_irq); 511 } else { 512 irq_set_chained_handler(IRQ_AUTO_1, via1_irq); 513 } 514 irq_set_chained_handler(IRQ_AUTO_2, via2_irq); 515 irq_set_chained_handler(IRQ_MAC_NUBUS, via_nubus_irq); 516 } 517 518 void via_irq_enable(int irq) { 519 int irq_src = IRQ_SRC(irq); 520 int irq_idx = IRQ_IDX(irq); 521 522 #ifdef DEBUG_IRQUSE 523 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq); 524 #endif 525 526 if (irq_src == 1) { 527 via1[vIER] = IER_SET_BIT(irq_idx); 528 } else if (irq_src == 2) { 529 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0) 530 via2[gIER] = IER_SET_BIT(irq_idx); 531 } else if (irq_src == 7) { 532 switch (macintosh_config->via_type) { 533 case MAC_VIA_II: 534 nubus_disabled &= ~(1 << irq_idx); 535 /* Enable the CA1 interrupt when no slot is disabled. */ 536 if (!nubus_disabled) 537 via2[gIER] = IER_SET_BIT(1); 538 break; 539 case MAC_VIA_IIci: 540 /* On RBV, enable the slot interrupt. 541 * SIER works like IER. 542 */ 543 via2[rSIER] = IER_SET_BIT(irq_idx); 544 break; 545 case MAC_VIA_QUADRA: 546 /* Make the port A line an input to enable the slot irq. 547 * But not on PowerBooks, that's ADB. 548 */ 549 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 550 (macintosh_config->adb_type != MAC_ADB_PB2)) 551 via2[vDirA] &= ~(1 << irq_idx); 552 break; 553 } 554 } 555 } 556 557 void via_irq_disable(int irq) { 558 int irq_src = IRQ_SRC(irq); 559 int irq_idx = IRQ_IDX(irq); 560 561 #ifdef DEBUG_IRQUSE 562 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq); 563 #endif 564 565 if (irq_src == 1) { 566 via1[vIER] = IER_CLR_BIT(irq_idx); 567 } else if (irq_src == 2) { 568 via2[gIER] = IER_CLR_BIT(irq_idx); 569 } else if (irq_src == 7) { 570 switch (macintosh_config->via_type) { 571 case MAC_VIA_II: 572 nubus_disabled |= 1 << irq_idx; 573 if (nubus_disabled) 574 via2[gIER] = IER_CLR_BIT(1); 575 break; 576 case MAC_VIA_IIci: 577 via2[rSIER] = IER_CLR_BIT(irq_idx); 578 break; 579 case MAC_VIA_QUADRA: 580 if ((macintosh_config->adb_type != MAC_ADB_PB1) && 581 (macintosh_config->adb_type != MAC_ADB_PB2)) 582 via2[vDirA] |= 1 << irq_idx; 583 break; 584 } 585 } 586 } 587 588 void via_irq_clear(int irq) { 589 int irq_src = IRQ_SRC(irq); 590 int irq_idx = IRQ_IDX(irq); 591 int irq_bit = 1 << irq_idx; 592 593 if (irq_src == 1) { 594 via1[vIFR] = irq_bit; 595 } else if (irq_src == 2) { 596 via2[gIFR] = irq_bit | rbv_clear; 597 } else if (irq_src == 7) { 598 /* FIXME: There is no way to clear an individual nubus slot 599 * IRQ flag, other than getting the device to do it. 600 */ 601 } 602 } 603 604 /* 605 * Returns nonzero if an interrupt is pending on the given 606 * VIA/IRQ combination. 607 */ 608 609 int via_irq_pending(int irq) 610 { 611 int irq_src = IRQ_SRC(irq); 612 int irq_idx = IRQ_IDX(irq); 613 int irq_bit = 1 << irq_idx; 614 615 if (irq_src == 1) { 616 return via1[vIFR] & irq_bit; 617 } else if (irq_src == 2) { 618 return via2[gIFR] & irq_bit; 619 } else if (irq_src == 7) { 620 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */ 621 return ~via2[gBufA] & irq_bit; 622 } 623 return 0; 624 } 625 626 void via1_set_head(int head) 627 { 628 if (head == 0) 629 via1[vBufA] &= ~VIA1A_vHeadSel; 630 else 631 via1[vBufA] |= VIA1A_vHeadSel; 632 } 633 EXPORT_SYMBOL(via1_set_head); 634