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 extern irqreturn_t mac_scc_dispatch(int, void *);
88
89 /*
90 * Initialize the VIAs
91 *
92 * First we figure out where they actually _are_ as well as what type of
93 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
94 * Then we pretty much clear them out and disable all IRQ sources.
95 *
96 * Note: the OSS is actually "detected" here and not in oss_init(). It just
97 * seems more logical to do it here since via_init() needs to know
98 * these things anyways.
99 */
100
via_init(void)101 void __init via_init(void)
102 {
103 switch(macintosh_config->via_type) {
104
105 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
106
107 case MAC_VIA_IIci:
108 via1 = (void *) VIA1_BASE;
109 if (macintosh_config->ident == MAC_MODEL_IIFX) {
110 via2 = NULL;
111 rbv_present = 0;
112 oss_present = 1;
113 } else {
114 via2 = (void *) RBV_BASE;
115 rbv_present = 1;
116 oss_present = 0;
117 }
118 if (macintosh_config->ident == MAC_MODEL_LCIII) {
119 rbv_clear = 0x00;
120 } else {
121 /* on most RBVs (& unlike the VIAs), you */
122 /* need to set bit 7 when you write to IFR */
123 /* in order for your clear to occur. */
124 rbv_clear = 0x80;
125 }
126 gIER = rIER;
127 gIFR = rIFR;
128 gBufA = rSIFR;
129 gBufB = rBufB;
130 break;
131
132 /* Quadra and early MacIIs agree on the VIA locations */
133
134 case MAC_VIA_QUADRA:
135 case MAC_VIA_II:
136 via1 = (void *) VIA1_BASE;
137 via2 = (void *) VIA2_BASE;
138 rbv_present = 0;
139 oss_present = 0;
140 rbv_clear = 0x00;
141 gIER = vIER;
142 gIFR = vIFR;
143 gBufA = vBufA;
144 gBufB = vBufB;
145 break;
146 default:
147 panic("UNKNOWN VIA TYPE");
148 }
149
150 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
151
152 printk(KERN_INFO "VIA2 at %p is ", via2);
153 if (rbv_present) {
154 printk("an RBV\n");
155 } else if (oss_present) {
156 printk("an OSS\n");
157 } else {
158 printk("a 6522 or clone\n");
159 }
160
161 #ifdef DEBUG_VIA
162 via_debug_dump();
163 #endif
164
165 /*
166 * Shut down all IRQ sources, reset the timers, and
167 * kill the timer latch on VIA1.
168 */
169
170 via1[vIER] = 0x7F;
171 via1[vIFR] = 0x7F;
172 via1[vT1LL] = 0;
173 via1[vT1LH] = 0;
174 via1[vT1CL] = 0;
175 via1[vT1CH] = 0;
176 via1[vT2CL] = 0;
177 via1[vT2CH] = 0;
178 via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
179 via1[vACR] &= ~0x03; /* disable port A & B latches */
180
181 /*
182 * SE/30: disable video IRQ
183 * XXX: testing for SE/30 VBL
184 */
185
186 if (macintosh_config->ident == MAC_MODEL_SE30) {
187 via1[vDirB] |= 0x40;
188 via1[vBufB] |= 0x40;
189 }
190
191 /*
192 * Set the RTC bits to a known state: all lines to outputs and
193 * RTC disabled (yes that's 0 to enable and 1 to disable).
194 */
195
196 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
197 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
198
199 /* Everything below this point is VIA2/RBV only... */
200
201 if (oss_present)
202 return;
203
204 /* Some machines support an alternate IRQ mapping that spreads */
205 /* Ethernet and Sound out to their own autolevel IRQs and moves */
206 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
207 /* that the IIfx emulates this alternate mapping using the OSS. */
208
209 via_alt_mapping = 0;
210 if (macintosh_config->via_type == MAC_VIA_QUADRA)
211 switch (macintosh_config->ident) {
212 case MAC_MODEL_C660:
213 case MAC_MODEL_Q840:
214 /* not applicable */
215 break;
216 case MAC_MODEL_P588:
217 case MAC_MODEL_TV:
218 case MAC_MODEL_PB140:
219 case MAC_MODEL_PB145:
220 case MAC_MODEL_PB160:
221 case MAC_MODEL_PB165:
222 case MAC_MODEL_PB165C:
223 case MAC_MODEL_PB170:
224 case MAC_MODEL_PB180:
225 case MAC_MODEL_PB180C:
226 case MAC_MODEL_PB190:
227 case MAC_MODEL_PB520:
228 /* not yet tested */
229 break;
230 default:
231 via_alt_mapping = 1;
232 via1[vDirB] |= 0x40;
233 via1[vBufB] &= ~0x40;
234 break;
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 /*
256 * Set vPCR for control line interrupts (but not on RBV)
257 */
258 if (!rbv_present) {
259 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
260 * are made negative edge triggered here.
261 */
262 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
263 /* CB2 (IRQ) indep. input, positive edge */
264 /* CA2 (DRQ) indep. input, positive edge */
265 via2[vPCR] = 0x66;
266 } else {
267 /* CB2 (IRQ) indep. input, negative edge */
268 /* CA2 (DRQ) indep. input, negative edge */
269 via2[vPCR] = 0x22;
270 }
271 }
272 }
273
274 /*
275 * Start the 100 Hz clock
276 */
277
via_init_clock(irq_handler_t func)278 void __init via_init_clock(irq_handler_t func)
279 {
280 via1[vACR] |= 0x40;
281 via1[vT1LL] = MAC_CLOCK_LOW;
282 via1[vT1LH] = MAC_CLOCK_HIGH;
283 via1[vT1CL] = MAC_CLOCK_LOW;
284 via1[vT1CH] = MAC_CLOCK_HIGH;
285
286 if (request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func))
287 pr_err("Couldn't register %s interrupt\n", "timer");
288 }
289
290 /*
291 * Register the interrupt dispatchers for VIA or RBV machines only.
292 */
293
via_register_interrupts(void)294 void __init via_register_interrupts(void)
295 {
296 if (via_alt_mapping) {
297 if (request_irq(IRQ_AUTO_1, via1_irq,
298 IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
299 (void *) via1))
300 pr_err("Couldn't register %s interrupt\n", "software");
301 if (request_irq(IRQ_AUTO_6, via1_irq,
302 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
303 (void *) via1))
304 pr_err("Couldn't register %s interrupt\n", "via1");
305 } else {
306 if (request_irq(IRQ_AUTO_1, via1_irq,
307 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
308 (void *) via1))
309 pr_err("Couldn't register %s interrupt\n", "via1");
310 }
311 if (request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
312 "via2", (void *) via2))
313 pr_err("Couldn't register %s interrupt\n", "via2");
314 if (!psc_present) {
315 if (request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
316 "scc", mac_scc_dispatch))
317 pr_err("Couldn't register %s interrupt\n", "scc");
318 }
319 if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq,
320 IRQ_FLG_LOCK|IRQ_FLG_FAST, "nubus", (void *) via2))
321 pr_err("Couldn't register %s interrupt\n", "nubus");
322 }
323
324 /*
325 * Debugging dump, used in various places to see what's going on.
326 */
327
via_debug_dump(void)328 void via_debug_dump(void)
329 {
330 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
331 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
332 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
333 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
334 if (oss_present) {
335 printk(KERN_DEBUG "VIA2: <OSS>\n");
336 } else if (rbv_present) {
337 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
338 (uint) via2[rIFR], (uint) via2[rIER]);
339 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
340 (uint) via2[rSIFR], (uint) via2[rSIER]);
341 } else {
342 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
343 (uint) via2[vDirA], (uint) via2[vDirB],
344 (uint) via2[vACR]);
345 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
346 (uint) via2[vPCR],
347 (uint) via2[vIFR], (uint) via2[vIER]);
348 }
349 }
350
351 /*
352 * This is always executed with interrupts disabled.
353 *
354 * TBI: get time offset between scheduling timer ticks
355 */
356
mac_gettimeoffset(void)357 unsigned long mac_gettimeoffset (void)
358 {
359 unsigned long ticks, offset = 0;
360
361 /* read VIA1 timer 2 current value */
362 ticks = via1[vT1CL] | (via1[vT1CH] << 8);
363 /* The probability of underflow is less than 2% */
364 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
365 /* Check for pending timer interrupt in VIA1 IFR */
366 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
367
368 ticks = MAC_CLOCK_TICK - ticks;
369 ticks = ticks * 10000L / MAC_CLOCK_TICK;
370
371 return ticks + offset;
372 }
373
374 /*
375 * Flush the L2 cache on Macs that have it by flipping
376 * the system into 24-bit mode for an instant.
377 */
378
via_flush_cache(void)379 void via_flush_cache(void)
380 {
381 via2[gBufB] &= ~VIA2B_vMode32;
382 via2[gBufB] |= VIA2B_vMode32;
383 }
384
385 /*
386 * Return the status of the L2 cache on a IIci
387 */
388
via_get_cache_disable(void)389 int via_get_cache_disable(void)
390 {
391 /* Safeguard against being called accidentally */
392 if (!via2) {
393 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
394 return 1;
395 }
396
397 return (int) via2[gBufB] & VIA2B_vCDis;
398 }
399
400 /*
401 * Initialize VIA2 for Nubus access
402 */
403
via_nubus_init(void)404 void __init via_nubus_init(void)
405 {
406 /* unlock nubus transactions */
407
408 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
409 (macintosh_config->adb_type != MAC_ADB_PB2)) {
410 /* set the line to be an output on non-RBV machines */
411 if (!rbv_present)
412 via2[vDirB] |= 0x02;
413
414 /* this seems to be an ADB bit on PMU machines */
415 /* according to MkLinux. -- jmt */
416 via2[gBufB] |= 0x02;
417 }
418
419 /* Disable all the slot interrupts (where possible). */
420
421 switch (macintosh_config->via_type) {
422 case MAC_VIA_II:
423 /* Just make the port A lines inputs. */
424 switch(macintosh_config->ident) {
425 case MAC_MODEL_II:
426 case MAC_MODEL_IIX:
427 case MAC_MODEL_IICX:
428 case MAC_MODEL_SE30:
429 /* The top two bits are RAM size outputs. */
430 via2[vDirA] &= 0xC0;
431 break;
432 default:
433 via2[vDirA] &= 0x80;
434 }
435 break;
436 case MAC_VIA_IIci:
437 /* RBV. Disable all the slot interrupts. SIER works like IER. */
438 via2[rSIER] = 0x7F;
439 break;
440 case MAC_VIA_QUADRA:
441 /* Disable the inactive slot interrupts by making those lines outputs. */
442 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
443 (macintosh_config->adb_type != MAC_ADB_PB2)) {
444 via2[vBufA] |= 0x7F;
445 via2[vDirA] |= 0x7F;
446 }
447 break;
448 }
449 }
450
451 /*
452 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
453 * via6522.c :-), disable/pending masks added.
454 */
455
via1_irq(int irq,void * dev_id)456 irqreturn_t via1_irq(int irq, void *dev_id)
457 {
458 int irq_num;
459 unsigned char irq_bit, events;
460
461 events = via1[vIFR] & via1[vIER] & 0x7F;
462 if (!events)
463 return IRQ_NONE;
464
465 irq_num = VIA1_SOURCE_BASE;
466 irq_bit = 1;
467 do {
468 if (events & irq_bit) {
469 via1[vIFR] = irq_bit;
470 m68k_handle_int(irq_num);
471 }
472 ++irq_num;
473 irq_bit <<= 1;
474 } while (events >= irq_bit);
475 return IRQ_HANDLED;
476 }
477
via2_irq(int irq,void * dev_id)478 irqreturn_t via2_irq(int irq, void *dev_id)
479 {
480 int irq_num;
481 unsigned char irq_bit, events;
482
483 events = via2[gIFR] & via2[gIER] & 0x7F;
484 if (!events)
485 return IRQ_NONE;
486
487 irq_num = VIA2_SOURCE_BASE;
488 irq_bit = 1;
489 do {
490 if (events & irq_bit) {
491 via2[gIFR] = irq_bit | rbv_clear;
492 m68k_handle_int(irq_num);
493 }
494 ++irq_num;
495 irq_bit <<= 1;
496 } while (events >= irq_bit);
497 return IRQ_HANDLED;
498 }
499
500 /*
501 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
502 * VIA2 dispatcher as a fast interrupt handler.
503 */
504
via_nubus_irq(int irq,void * dev_id)505 irqreturn_t via_nubus_irq(int irq, void *dev_id)
506 {
507 int slot_irq;
508 unsigned char slot_bit, events;
509
510 events = ~via2[gBufA] & 0x7F;
511 if (rbv_present)
512 events &= via2[rSIER];
513 else
514 events &= ~via2[vDirA];
515 if (!events)
516 return IRQ_NONE;
517
518 do {
519 slot_irq = IRQ_NUBUS_F;
520 slot_bit = 0x40;
521 do {
522 if (events & slot_bit) {
523 events &= ~slot_bit;
524 m68k_handle_int(slot_irq);
525 }
526 --slot_irq;
527 slot_bit >>= 1;
528 } while (events);
529
530 /* clear the CA1 interrupt and make certain there's no more. */
531 via2[gIFR] = 0x02 | rbv_clear;
532 events = ~via2[gBufA] & 0x7F;
533 if (rbv_present)
534 events &= via2[rSIER];
535 else
536 events &= ~via2[vDirA];
537 } while (events);
538 return IRQ_HANDLED;
539 }
540
via_irq_enable(int irq)541 void via_irq_enable(int irq) {
542 int irq_src = IRQ_SRC(irq);
543 int irq_idx = IRQ_IDX(irq);
544
545 #ifdef DEBUG_IRQUSE
546 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
547 #endif
548
549 if (irq_src == 1) {
550 via1[vIER] = IER_SET_BIT(irq_idx);
551 } else if (irq_src == 2) {
552 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
553 via2[gIER] = IER_SET_BIT(irq_idx);
554 } else if (irq_src == 7) {
555 switch (macintosh_config->via_type) {
556 case MAC_VIA_II:
557 nubus_disabled &= ~(1 << irq_idx);
558 /* Enable the CA1 interrupt when no slot is disabled. */
559 if (!nubus_disabled)
560 via2[gIER] = IER_SET_BIT(1);
561 break;
562 case MAC_VIA_IIci:
563 /* On RBV, enable the slot interrupt.
564 * SIER works like IER.
565 */
566 via2[rSIER] = IER_SET_BIT(irq_idx);
567 break;
568 case MAC_VIA_QUADRA:
569 /* Make the port A line an input to enable the slot irq.
570 * But not on PowerBooks, that's ADB.
571 */
572 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
573 (macintosh_config->adb_type != MAC_ADB_PB2))
574 via2[vDirA] &= ~(1 << irq_idx);
575 break;
576 }
577 }
578 }
579
via_irq_disable(int irq)580 void via_irq_disable(int irq) {
581 int irq_src = IRQ_SRC(irq);
582 int irq_idx = IRQ_IDX(irq);
583
584 #ifdef DEBUG_IRQUSE
585 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
586 #endif
587
588 if (irq_src == 1) {
589 via1[vIER] = IER_CLR_BIT(irq_idx);
590 } else if (irq_src == 2) {
591 via2[gIER] = IER_CLR_BIT(irq_idx);
592 } else if (irq_src == 7) {
593 switch (macintosh_config->via_type) {
594 case MAC_VIA_II:
595 nubus_disabled |= 1 << irq_idx;
596 if (nubus_disabled)
597 via2[gIER] = IER_CLR_BIT(1);
598 break;
599 case MAC_VIA_IIci:
600 via2[rSIER] = IER_CLR_BIT(irq_idx);
601 break;
602 case MAC_VIA_QUADRA:
603 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
604 (macintosh_config->adb_type != MAC_ADB_PB2))
605 via2[vDirA] |= 1 << irq_idx;
606 break;
607 }
608 }
609 }
610
via_irq_clear(int irq)611 void via_irq_clear(int irq) {
612 int irq_src = IRQ_SRC(irq);
613 int irq_idx = IRQ_IDX(irq);
614 int irq_bit = 1 << irq_idx;
615
616 if (irq_src == 1) {
617 via1[vIFR] = irq_bit;
618 } else if (irq_src == 2) {
619 via2[gIFR] = irq_bit | rbv_clear;
620 } else if (irq_src == 7) {
621 /* FIXME: There is no way to clear an individual nubus slot
622 * IRQ flag, other than getting the device to do it.
623 */
624 }
625 }
626
627 /*
628 * Returns nonzero if an interrupt is pending on the given
629 * VIA/IRQ combination.
630 */
631
via_irq_pending(int irq)632 int via_irq_pending(int irq)
633 {
634 int irq_src = IRQ_SRC(irq);
635 int irq_idx = IRQ_IDX(irq);
636 int irq_bit = 1 << irq_idx;
637
638 if (irq_src == 1) {
639 return via1[vIFR] & irq_bit;
640 } else if (irq_src == 2) {
641 return via2[gIFR] & irq_bit;
642 } else if (irq_src == 7) {
643 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
644 return ~via2[gBufA] & irq_bit;
645 }
646 return 0;
647 }
648