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/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 /* To disable a NuBus slot on Quadras we make that slot IRQ line an output set
66 * high. On RBV we just use the slot interrupt enable register. On Macs with
67 * genuine VIA chips we must use nubus_disabled to keep track of disabled slot
68 * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
69 * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
70 * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
71 * because closing one of those drivers can mask all of the NuBus interrupts.
72 * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
73 * possible to get interrupts from cards that MacOS or the ROM has configured
74 * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
75 * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
76 */
77 static u8 nubus_disabled;
78
79 void via_debug_dump(void);
80 irqreturn_t via1_irq(int, void *);
81 irqreturn_t via2_irq(int, void *);
82 irqreturn_t via_nubus_irq(int, void *);
83 void via_irq_enable(int irq);
84 void via_irq_disable(int irq);
85 void via_irq_clear(int irq);
86
87 /*
88 * Initialize the VIAs
89 *
90 * First we figure out where they actually _are_ as well as what type of
91 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
92 * Then we pretty much clear them out and disable all IRQ sources.
93 *
94 * Note: the OSS is actually "detected" here and not in oss_init(). It just
95 * seems more logical to do it here since via_init() needs to know
96 * these things anyways.
97 */
98
via_init(void)99 void __init via_init(void)
100 {
101 switch(macintosh_config->via_type) {
102
103 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
104
105 case MAC_VIA_IIci:
106 via1 = (void *) VIA1_BASE;
107 if (macintosh_config->ident == MAC_MODEL_IIFX) {
108 via2 = NULL;
109 rbv_present = 0;
110 oss_present = 1;
111 } else {
112 via2 = (void *) RBV_BASE;
113 rbv_present = 1;
114 oss_present = 0;
115 }
116 if (macintosh_config->ident == MAC_MODEL_LCIII) {
117 rbv_clear = 0x00;
118 } else {
119 /* on most RBVs (& unlike the VIAs), you */
120 /* need to set bit 7 when you write to IFR */
121 /* in order for your clear to occur. */
122 rbv_clear = 0x80;
123 }
124 gIER = rIER;
125 gIFR = rIFR;
126 gBufA = rSIFR;
127 gBufB = rBufB;
128 break;
129
130 /* Quadra and early MacIIs agree on the VIA locations */
131
132 case MAC_VIA_QUADRA:
133 case MAC_VIA_II:
134 via1 = (void *) VIA1_BASE;
135 via2 = (void *) VIA2_BASE;
136 rbv_present = 0;
137 oss_present = 0;
138 rbv_clear = 0x00;
139 gIER = vIER;
140 gIFR = vIFR;
141 gBufA = vBufA;
142 gBufB = vBufB;
143 break;
144 default:
145 panic("UNKNOWN VIA TYPE");
146 }
147
148 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
149
150 printk(KERN_INFO "VIA2 at %p is ", via2);
151 if (rbv_present) {
152 printk("an RBV\n");
153 } else if (oss_present) {
154 printk("an OSS\n");
155 } else {
156 printk("a 6522 or clone\n");
157 }
158
159 #ifdef DEBUG_VIA
160 via_debug_dump();
161 #endif
162
163 /*
164 * Shut down all IRQ sources, reset the timers, and
165 * kill the timer latch on VIA1.
166 */
167
168 via1[vIER] = 0x7F;
169 via1[vIFR] = 0x7F;
170 via1[vT1LL] = 0;
171 via1[vT1LH] = 0;
172 via1[vT1CL] = 0;
173 via1[vT1CH] = 0;
174 via1[vT2CL] = 0;
175 via1[vT2CH] = 0;
176 via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
177 via1[vACR] &= ~0x03; /* disable port A & B latches */
178
179 /*
180 * SE/30: disable video IRQ
181 * XXX: testing for SE/30 VBL
182 */
183
184 if (macintosh_config->ident == MAC_MODEL_SE30) {
185 via1[vDirB] |= 0x40;
186 via1[vBufB] |= 0x40;
187 }
188
189 /*
190 * Set the RTC bits to a known state: all lines to outputs and
191 * RTC disabled (yes that's 0 to enable and 1 to disable).
192 */
193
194 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
195 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
196
197 /* Everything below this point is VIA2/RBV only... */
198
199 if (oss_present)
200 return;
201
202 /* Some machines support an alternate IRQ mapping that spreads */
203 /* Ethernet and Sound out to their own autolevel IRQs and moves */
204 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
205 /* that the IIfx emulates this alternate mapping using the OSS. */
206
207 via_alt_mapping = 0;
208 if (macintosh_config->via_type == MAC_VIA_QUADRA)
209 switch (macintosh_config->ident) {
210 case MAC_MODEL_C660:
211 case MAC_MODEL_Q840:
212 /* not applicable */
213 break;
214 case MAC_MODEL_P588:
215 case MAC_MODEL_TV:
216 case MAC_MODEL_PB140:
217 case MAC_MODEL_PB145:
218 case MAC_MODEL_PB160:
219 case MAC_MODEL_PB165:
220 case MAC_MODEL_PB165C:
221 case MAC_MODEL_PB170:
222 case MAC_MODEL_PB180:
223 case MAC_MODEL_PB180C:
224 case MAC_MODEL_PB190:
225 case MAC_MODEL_PB520:
226 /* not yet tested */
227 break;
228 default:
229 via_alt_mapping = 1;
230 via1[vDirB] |= 0x40;
231 via1[vBufB] &= ~0x40;
232 break;
233 }
234
235 /*
236 * Now initialize VIA2. For RBV we just kill all interrupts;
237 * for a regular VIA we also reset the timers and stuff.
238 */
239
240 via2[gIER] = 0x7F;
241 via2[gIFR] = 0x7F | rbv_clear;
242 if (!rbv_present) {
243 via2[vT1LL] = 0;
244 via2[vT1LH] = 0;
245 via2[vT1CL] = 0;
246 via2[vT1CH] = 0;
247 via2[vT2CL] = 0;
248 via2[vT2CH] = 0;
249 via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
250 via2[vACR] &= ~0x03; /* disable port A & B latches */
251 }
252
253 /*
254 * Set vPCR for control line interrupts (but not on RBV)
255 */
256 if (!rbv_present) {
257 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
258 * are made negative edge triggered here.
259 */
260 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
261 /* CB2 (IRQ) indep. input, positive edge */
262 /* CA2 (DRQ) indep. input, positive edge */
263 via2[vPCR] = 0x66;
264 } else {
265 /* CB2 (IRQ) indep. input, negative edge */
266 /* CA2 (DRQ) indep. input, negative edge */
267 via2[vPCR] = 0x22;
268 }
269 }
270 }
271
272 /*
273 * Start the 100 Hz clock
274 */
275
via_init_clock(irq_handler_t func)276 void __init via_init_clock(irq_handler_t func)
277 {
278 via1[vACR] |= 0x40;
279 via1[vT1LL] = MAC_CLOCK_LOW;
280 via1[vT1LH] = MAC_CLOCK_HIGH;
281 via1[vT1CL] = MAC_CLOCK_LOW;
282 via1[vT1CH] = MAC_CLOCK_HIGH;
283
284 if (request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func))
285 pr_err("Couldn't register %s interrupt\n", "timer");
286 }
287
288 /*
289 * Register the interrupt dispatchers for VIA or RBV machines only.
290 */
291
via_register_interrupts(void)292 void __init via_register_interrupts(void)
293 {
294 if (via_alt_mapping) {
295 if (request_irq(IRQ_AUTO_1, via1_irq,
296 IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
297 (void *) via1))
298 pr_err("Couldn't register %s interrupt\n", "software");
299 if (request_irq(IRQ_AUTO_6, via1_irq,
300 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
301 (void *) via1))
302 pr_err("Couldn't register %s interrupt\n", "via1");
303 } else {
304 if (request_irq(IRQ_AUTO_1, via1_irq,
305 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
306 (void *) via1))
307 pr_err("Couldn't register %s interrupt\n", "via1");
308 }
309 if (request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
310 "via2", (void *) via2))
311 pr_err("Couldn't register %s interrupt\n", "via2");
312 if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq,
313 IRQ_FLG_LOCK|IRQ_FLG_FAST, "nubus", (void *) via2))
314 pr_err("Couldn't register %s interrupt\n", "nubus");
315 }
316
317 /*
318 * Debugging dump, used in various places to see what's going on.
319 */
320
via_debug_dump(void)321 void via_debug_dump(void)
322 {
323 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
324 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
325 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
326 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
327 if (oss_present) {
328 printk(KERN_DEBUG "VIA2: <OSS>\n");
329 } else if (rbv_present) {
330 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
331 (uint) via2[rIFR], (uint) via2[rIER]);
332 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
333 (uint) via2[rSIFR], (uint) via2[rSIER]);
334 } else {
335 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
336 (uint) via2[vDirA], (uint) via2[vDirB],
337 (uint) via2[vACR]);
338 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
339 (uint) via2[vPCR],
340 (uint) via2[vIFR], (uint) via2[vIER]);
341 }
342 }
343
344 /*
345 * This is always executed with interrupts disabled.
346 *
347 * TBI: get time offset between scheduling timer ticks
348 */
349
mac_gettimeoffset(void)350 unsigned long mac_gettimeoffset (void)
351 {
352 unsigned long ticks, offset = 0;
353
354 /* read VIA1 timer 2 current value */
355 ticks = via1[vT1CL] | (via1[vT1CH] << 8);
356 /* The probability of underflow is less than 2% */
357 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
358 /* Check for pending timer interrupt in VIA1 IFR */
359 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
360
361 ticks = MAC_CLOCK_TICK - ticks;
362 ticks = ticks * 10000L / MAC_CLOCK_TICK;
363
364 return ticks + offset;
365 }
366
367 /*
368 * Flush the L2 cache on Macs that have it by flipping
369 * the system into 24-bit mode for an instant.
370 */
371
via_flush_cache(void)372 void via_flush_cache(void)
373 {
374 via2[gBufB] &= ~VIA2B_vMode32;
375 via2[gBufB] |= VIA2B_vMode32;
376 }
377
378 /*
379 * Return the status of the L2 cache on a IIci
380 */
381
via_get_cache_disable(void)382 int via_get_cache_disable(void)
383 {
384 /* Safeguard against being called accidentally */
385 if (!via2) {
386 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
387 return 1;
388 }
389
390 return (int) via2[gBufB] & VIA2B_vCDis;
391 }
392
393 /*
394 * Initialize VIA2 for Nubus access
395 */
396
via_nubus_init(void)397 void __init via_nubus_init(void)
398 {
399 /* unlock nubus transactions */
400
401 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
402 (macintosh_config->adb_type != MAC_ADB_PB2)) {
403 /* set the line to be an output on non-RBV machines */
404 if (!rbv_present)
405 via2[vDirB] |= 0x02;
406
407 /* this seems to be an ADB bit on PMU machines */
408 /* according to MkLinux. -- jmt */
409 via2[gBufB] |= 0x02;
410 }
411
412 /* Disable all the slot interrupts (where possible). */
413
414 switch (macintosh_config->via_type) {
415 case MAC_VIA_II:
416 /* Just make the port A lines inputs. */
417 switch(macintosh_config->ident) {
418 case MAC_MODEL_II:
419 case MAC_MODEL_IIX:
420 case MAC_MODEL_IICX:
421 case MAC_MODEL_SE30:
422 /* The top two bits are RAM size outputs. */
423 via2[vDirA] &= 0xC0;
424 break;
425 default:
426 via2[vDirA] &= 0x80;
427 }
428 break;
429 case MAC_VIA_IIci:
430 /* RBV. Disable all the slot interrupts. SIER works like IER. */
431 via2[rSIER] = 0x7F;
432 break;
433 case MAC_VIA_QUADRA:
434 /* Disable the inactive slot interrupts by making those lines outputs. */
435 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
436 (macintosh_config->adb_type != MAC_ADB_PB2)) {
437 via2[vBufA] |= 0x7F;
438 via2[vDirA] |= 0x7F;
439 }
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
via1_irq(int irq,void * dev_id)449 irqreturn_t via1_irq(int irq, void *dev_id)
450 {
451 int irq_num;
452 unsigned char irq_bit, events;
453
454 events = via1[vIFR] & via1[vIER] & 0x7F;
455 if (!events)
456 return IRQ_NONE;
457
458 irq_num = VIA1_SOURCE_BASE;
459 irq_bit = 1;
460 do {
461 if (events & irq_bit) {
462 via1[vIFR] = irq_bit;
463 m68k_handle_int(irq_num);
464 }
465 ++irq_num;
466 irq_bit <<= 1;
467 } while (events >= irq_bit);
468 return IRQ_HANDLED;
469 }
470
via2_irq(int irq,void * dev_id)471 irqreturn_t via2_irq(int irq, void *dev_id)
472 {
473 int irq_num;
474 unsigned char irq_bit, events;
475
476 events = via2[gIFR] & via2[gIER] & 0x7F;
477 if (!events)
478 return IRQ_NONE;
479
480 irq_num = VIA2_SOURCE_BASE;
481 irq_bit = 1;
482 do {
483 if (events & irq_bit) {
484 via2[gIFR] = irq_bit | rbv_clear;
485 m68k_handle_int(irq_num);
486 }
487 ++irq_num;
488 irq_bit <<= 1;
489 } while (events >= irq_bit);
490 return IRQ_HANDLED;
491 }
492
493 /*
494 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
495 * VIA2 dispatcher as a fast interrupt handler.
496 */
497
via_nubus_irq(int irq,void * dev_id)498 irqreturn_t via_nubus_irq(int irq, void *dev_id)
499 {
500 int slot_irq;
501 unsigned char slot_bit, events;
502
503 events = ~via2[gBufA] & 0x7F;
504 if (rbv_present)
505 events &= via2[rSIER];
506 else
507 events &= ~via2[vDirA];
508 if (!events)
509 return IRQ_NONE;
510
511 do {
512 slot_irq = IRQ_NUBUS_F;
513 slot_bit = 0x40;
514 do {
515 if (events & slot_bit) {
516 events &= ~slot_bit;
517 m68k_handle_int(slot_irq);
518 }
519 --slot_irq;
520 slot_bit >>= 1;
521 } while (events);
522
523 /* clear the CA1 interrupt and make certain there's no more. */
524 via2[gIFR] = 0x02 | rbv_clear;
525 events = ~via2[gBufA] & 0x7F;
526 if (rbv_present)
527 events &= via2[rSIER];
528 else
529 events &= ~via2[vDirA];
530 } while (events);
531 return IRQ_HANDLED;
532 }
533
via_irq_enable(int irq)534 void via_irq_enable(int irq) {
535 int irq_src = IRQ_SRC(irq);
536 int irq_idx = IRQ_IDX(irq);
537
538 #ifdef DEBUG_IRQUSE
539 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
540 #endif
541
542 if (irq_src == 1) {
543 via1[vIER] = IER_SET_BIT(irq_idx);
544 } else if (irq_src == 2) {
545 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
546 via2[gIER] = IER_SET_BIT(irq_idx);
547 } else if (irq_src == 7) {
548 switch (macintosh_config->via_type) {
549 case MAC_VIA_II:
550 nubus_disabled &= ~(1 << irq_idx);
551 /* Enable the CA1 interrupt when no slot is disabled. */
552 if (!nubus_disabled)
553 via2[gIER] = IER_SET_BIT(1);
554 break;
555 case MAC_VIA_IIci:
556 /* On RBV, enable the slot interrupt.
557 * SIER works like IER.
558 */
559 via2[rSIER] = IER_SET_BIT(irq_idx);
560 break;
561 case MAC_VIA_QUADRA:
562 /* Make the port A line an input to enable the slot irq.
563 * But not on PowerBooks, that's ADB.
564 */
565 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
566 (macintosh_config->adb_type != MAC_ADB_PB2))
567 via2[vDirA] &= ~(1 << irq_idx);
568 break;
569 }
570 }
571 }
572
via_irq_disable(int irq)573 void via_irq_disable(int irq) {
574 int irq_src = IRQ_SRC(irq);
575 int irq_idx = IRQ_IDX(irq);
576
577 #ifdef DEBUG_IRQUSE
578 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
579 #endif
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 nubus_disabled |= 1 << irq_idx;
589 if (nubus_disabled)
590 via2[gIER] = IER_CLR_BIT(1);
591 break;
592 case MAC_VIA_IIci:
593 via2[rSIER] = IER_CLR_BIT(irq_idx);
594 break;
595 case MAC_VIA_QUADRA:
596 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
597 (macintosh_config->adb_type != MAC_ADB_PB2))
598 via2[vDirA] |= 1 << irq_idx;
599 break;
600 }
601 }
602 }
603
via_irq_clear(int irq)604 void via_irq_clear(int irq) {
605 int irq_src = IRQ_SRC(irq);
606 int irq_idx = IRQ_IDX(irq);
607 int irq_bit = 1 << irq_idx;
608
609 if (irq_src == 1) {
610 via1[vIFR] = irq_bit;
611 } else if (irq_src == 2) {
612 via2[gIFR] = irq_bit | rbv_clear;
613 } else if (irq_src == 7) {
614 /* FIXME: There is no way to clear an individual nubus slot
615 * IRQ flag, other than getting the device to do it.
616 */
617 }
618 }
619
620 /*
621 * Returns nonzero if an interrupt is pending on the given
622 * VIA/IRQ combination.
623 */
624
via_irq_pending(int irq)625 int via_irq_pending(int irq)
626 {
627 int irq_src = IRQ_SRC(irq);
628 int irq_idx = IRQ_IDX(irq);
629 int irq_bit = 1 << irq_idx;
630
631 if (irq_src == 1) {
632 return via1[vIFR] & irq_bit;
633 } else if (irq_src == 2) {
634 return via2[gIFR] & irq_bit;
635 } else if (irq_src == 7) {
636 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
637 return ~via2[gBufA] & irq_bit;
638 }
639 return 0;
640 }
641
via1_set_head(int head)642 void via1_set_head(int head)
643 {
644 if (head == 0)
645 via1[vBufA] &= ~VIA1A_vHeadSel;
646 else
647 via1[vBufA] |= VIA1A_vHeadSel;
648 }
649 EXPORT_SYMBOL(via1_set_head);
650