File: /usr/src/linux/arch/m68k/mac/via.c
1 /*
2 * 6522 Versatile Interface Adapter (VIA)
3 *
4 * There are two of these on the Mac II. Some IRQ's 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 * PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
17 * by Erik Vogan and adapted to Linux by Joshua M. Thompson (funaho@jurai.org)
18 *
19 */
20
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/delay.h>
25 #include <linux/init.h>
26
27 #include <linux/ide.h>
28
29 #include <asm/traps.h>
30 #include <asm/bootinfo.h>
31 #include <asm/macintosh.h>
32 #include <asm/macints.h>
33 #include <asm/machw.h>
34 #include <asm/mac_via.h>
35 #include <asm/mac_psc.h>
36
37 volatile __u8 *via1, *via2;
38 #if 0
39 /* See note in mac_via.h about how this is possibly not useful */
40 volatile long *via_memory_bogon=(long *)&via_memory_bogon;
41 #endif
42 int rbv_present,via_alt_mapping;
43 __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 * _consistantly_ 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 static int nubus_active = 0;
66
67 void via_debug_dump(void);
68 void via1_irq(int, void *, struct pt_regs *);
69 void via2_irq(int, void *, struct pt_regs *);
70 void via_nubus_irq(int, void *, struct pt_regs *);
71 void via_irq_enable(int irq);
72 void via_irq_disable(int irq);
73 void via_irq_clear(int irq);
74
75 extern void mac_bang(int, void *, struct pt_regs *);
76 extern void mac_scc_dispatch(int, void *, struct pt_regs *);
77 extern int oss_present;
78
79 /*
80 * Initialize the VIAs
81 *
82 * First we figure out where they actually _are_ as well as what type of
83 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
84 * Then we pretty much clear them out and disable all IRQ sources.
85 *
86 * Note: the OSS is actually "detected" here and not in oss_init(). It just
87 * seems more logical to do it here since via_init() needs to know
88 * these things anyways.
89 */
90
91 void __init via_init(void)
92 {
93 switch(macintosh_config->via_type) {
94
95 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
96
97 case MAC_VIA_IIci:
98 via1 = (void *) VIA1_BASE;
99 if (macintosh_config->ident == MAC_MODEL_IIFX) {
100 via2 = NULL;
101 rbv_present = 0;
102 oss_present = 1;
103 } else {
104 via2 = (void *) RBV_BASE;
105 rbv_present = 1;
106 oss_present = 0;
107 }
108 if (macintosh_config->ident == MAC_MODEL_LCIII) {
109 rbv_clear = 0x00;
110 } else {
111 /* on most RBVs (& unlike the VIAs), you */
112 /* need to set bit 7 when you write to IFR */
113 /* in order for your clear to occur. */
114 rbv_clear = 0x80;
115 }
116 gIER = rIER;
117 gIFR = rIFR;
118 gBufA = rSIFR;
119 gBufB = rBufB;
120 break;
121
122 /* Quadra and early MacIIs agree on the VIA locations */
123
124 case MAC_VIA_QUADRA:
125 case MAC_VIA_II:
126 via1 = (void *) VIA1_BASE;
127 via2 = (void *) VIA2_BASE;
128 rbv_present = 0;
129 oss_present = 0;
130 rbv_clear = 0x00;
131 gIER = vIER;
132 gIFR = vIFR;
133 gBufA = vBufA;
134 gBufB = vBufB;
135 break;
136 default:
137 panic("UNKNOWN VIA TYPE");
138 }
139
140 printk("VIA1 at %p is a 6522 or clone\n", via1);
141
142 printk("VIA2 at %p is ", via2);
143 if (rbv_present) {
144 printk("an RBV\n");
145 } else if (oss_present) {
146 printk("an OSS\n");
147 } else {
148 printk("a 6522 or clone\n");
149 }
150
151 #ifdef DEBUG_VIA
152 via_debug_dump();
153 #endif
154
155 /*
156 * Shut down all IRQ sources, reset the timers, and
157 * kill the timer latch on VIA1.
158 */
159
160 via1[vIER] = 0x7F;
161 via1[vIFR] = 0x7F;
162 via1[vT1LL] = 0;
163 via1[vT1LH] = 0;
164 via1[vT1CL] = 0;
165 via1[vT1CH] = 0;
166 via1[vT2CL] = 0;
167 via1[vT2CH] = 0;
168 via1[vACR] &= 0x3F;
169
170 /*
171 * SE/30: disable video IRQ
172 * XXX: testing for SE/30 VBL
173 */
174
175 if (macintosh_config->ident == MAC_MODEL_SE30) {
176 via1[vDirB] |= 0x40;
177 via1[vBufB] |= 0x40;
178 }
179
180 /*
181 * Set the RTC bits to a known state: all lines to outputs and
182 * RTC disabled (yes that's 0 to enable and 1 to disable).
183 */
184
185 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
186 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
187
188 /* Everything below this point is VIA2/RBV only... */
189
190 if (oss_present) return;
191
192 #if 1
193 /* Some machines support an alternate IRQ mapping that spreads */
194 /* Ethernet and Sound out to their own autolevel IRQs and moves */
195 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
196 /* that the IIfx emulates this alternate mapping using the OSS. */
197
198 switch(macintosh_config->ident) {
199 case MAC_MODEL_C610:
200 case MAC_MODEL_Q610:
201 case MAC_MODEL_C650:
202 case MAC_MODEL_Q650:
203 case MAC_MODEL_Q700:
204 case MAC_MODEL_Q800:
205 case MAC_MODEL_Q900:
206 case MAC_MODEL_Q950:
207 via_alt_mapping = 1;
208 via1[vDirB] |= 0x40;
209 via1[vBufB] &= ~0x40;
210 break;
211 default:
212 via_alt_mapping = 0;
213 break;
214 }
215 #else
216 /* The alernate IRQ mapping seems to just not work. Anyone with a */
217 /* supported machine is welcome to take a stab at fixing it. It */
218 /* _should_ work on the following Quadras: 610,650,700,800,900,950 */
219 /* - 1999-06-12 (jmt) */
220
221 via_alt_mapping = 0;
222 #endif
223
224 /*
225 * Now initialize VIA2. For RBV we just kill all interrupts;
226 * for a regular VIA we also reset the timers and stuff.
227 */
228
229 via2[gIER] = 0x7F;
230 via2[gIFR] = 0x7F | rbv_clear;
231 if (!rbv_present) {
232 via2[vT1LL] = 0;
233 via2[vT1LH] = 0;
234 via2[vT1CL] = 0;
235 via2[vT1CH] = 0;
236 via2[vT2CL] = 0;
237 via2[vT2CH] = 0;
238 via2[vACR] &= 0x3F;
239 }
240 }
241
242 /*
243 * Start the 100 Hz clock
244 */
245
246 void __init via_init_clock(void (*func)(int, void *, struct pt_regs *))
247 {
248 via1[vACR] |= 0x40;
249 via1[vT1LL] = MAC_CLOCK_LOW;
250 via1[vT1LH] = MAC_CLOCK_HIGH;
251 via1[vT1CL] = MAC_CLOCK_LOW;
252 via1[vT1CH] = MAC_CLOCK_HIGH;
253
254 request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
255 }
256
257 /*
258 * Register the interrupt dispatchers for VIA or RBV machines only.
259 */
260
261 void __init via_register_interrupts(void)
262 {
263 if (via_alt_mapping) {
264 sys_request_irq(IRQ_AUTO_1, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
265 "software", (void *) via1);
266 sys_request_irq(IRQ_AUTO_6, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
267 "via1", (void *) via1);
268 } else {
269 sys_request_irq(IRQ_AUTO_1, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
270 "via1", (void *) via1);
271 #if 0 /* interferes with serial on some machines */
272 if (!psc_present) {
273 sys_request_irq(IRQ_AUTO_6, mac_bang, IRQ_FLG_LOCK,
274 "Off Switch", mac_bang);
275 }
276 #endif
277 }
278 sys_request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
279 "via2", (void *) via2);
280 if (!psc_present) {
281 sys_request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
282 "scc", mac_scc_dispatch);
283 }
284 request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
285 "nubus", (void *) via2);
286 }
287
288 /*
289 * Debugging dump, used in various places to see what's going on.
290 */
291
292 void via_debug_dump(void)
293 {
294 printk("VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
295 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
296 printk(" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
297 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
298 if (oss_present) {
299 printk("VIA2: <OSS>\n");
300 } else if (rbv_present) {
301 printk("VIA2: IFR = 0x%02X IER = 0x%02X\n",
302 (uint) via2[rIFR], (uint) via2[rIER]);
303 printk(" SIFR = 0x%02X SIER = 0x%02X\n",
304 (uint) via2[rSIFR], (uint) via2[rSIER]);
305 } else {
306 printk("VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
307 (uint) via2[vDirA], (uint) via2[vDirB],
308 (uint) via2[vACR]);
309 printk(" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
310 (uint) via2[vPCR],
311 (uint) via2[vIFR], (uint) via2[vIER]);
312 }
313 }
314
315 /*
316 * This is always executed with interrupts disabled.
317 *
318 * TBI: get time offset between scheduling timer ticks
319 */
320
321 unsigned long mac_gettimeoffset (void)
322 {
323 unsigned long ticks, offset = 0;
324
325 /* read VIA1 timer 2 current value */
326 ticks = via1[vT1CL] | (via1[vT1CH] << 8);
327 /* The probability of underflow is less than 2% */
328 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
329 /* Check for pending timer interrupt in VIA1 IFR */
330 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
331
332 ticks = MAC_CLOCK_TICK - ticks;
333 ticks = ticks * 10000L / MAC_CLOCK_TICK;
334
335 return ticks + offset;
336 }
337
338 /*
339 * Flush the L2 cache on Macs that have it by flipping
340 * the system into 24-bit mode for an instant.
341 */
342
343 void via_flush_cache(void)
344 {
345 via2[gBufB] &= ~VIA2B_vMode32;
346 via2[gBufB] |= VIA2B_vMode32;
347 }
348
349 /*
350 * Return the status of the L2 cache on a IIci
351 */
352
353 int via_get_cache_disable(void)
354 {
355 /* Safeguard against being called accidentally */
356 if (!via2) {
357 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
358 return 1;
359 }
360
361 return (int) via2[gBufB] & VIA2B_vCDis;
362 }
363
364 /*
365 * Initialize VIA2 for Nubus access
366 */
367
368 void __init via_nubus_init(void)
369 {
370 /* don't set nubus_active = 0 here, it kills the Baboon */
371 /* interrupt that we've already registered. */
372
373 /* unlock nubus transactions */
374
375 if (!rbv_present) {
376 /* set the line to be an output on non-RBV machines */
377 via2[vDirB] |= 0x02;
378 }
379
380 /* this seems to be an ADB bit on PMU machines */
381 /* according to MkLinux. -- jmt */
382
383 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
384 (macintosh_config->adb_type != MAC_ADB_PB2)) {
385 via2[gBufB] |= 0x02;
386 }
387
388 /* disable nubus slot interrupts. */
389 if (rbv_present) {
390 via2[rSIER] = 0x7F;
391 via2[rSIER] = nubus_active | 0x80;
392 } else {
393 via2[vBufA] = 0xFF;
394 via2[vDirA] = ~nubus_active;
395 }
396 }
397
398 /*
399 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
400 * via6522.c :-), disable/pending masks added.
401 *
402 * The new interrupt architecture in macints.c takes care of a lot of the
403 * gruntwork for us, including tallying the interrupts and calling the
404 * handlers on the linked list. All we need to do here is basically generate
405 * the machspec interrupt number after clearing the interrupt.
406 */
407
408 void via1_irq(int irq, void *dev_id, struct pt_regs *regs)
409 {
410 int irq_bit, i;
411 unsigned char events, mask;
412
413 mask = via1[vIER] & 0x7F;
414 if (!(events = via1[vIFR] & mask)) return;
415
416 for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
417 if (events & irq_bit) {
418 via1[vIER] = irq_bit;
419 mac_do_irq_list(VIA1_SOURCE_BASE + i, regs);
420 via1[vIFR] = irq_bit;
421 via1[vIER] = irq_bit | 0x80;
422 }
423
424 #if 0 /* freakin' pmu is doing weird stuff */
425 if (!oss_present) {
426 /* This (still) seems to be necessary to get IDE
427 working. However, if you enable VBL interrupts,
428 you're screwed... */
429 /* FIXME: should we check the SLOTIRQ bit before
430 pulling this stunt? */
431 /* No, it won't be set. that's why we're doing this. */
432 via_irq_disable(IRQ_MAC_NUBUS);
433 via_irq_clear(IRQ_MAC_NUBUS);
434 mac_do_irq_list(IRQ_MAC_NUBUS, regs);
435 via_irq_enable(IRQ_MAC_NUBUS);
436 }
437 #endif
438 }
439
440 void via2_irq(int irq, void *dev_id, struct pt_regs *regs)
441 {
442 int irq_bit, i;
443 unsigned char events, mask;
444
445 mask = via2[gIER] & 0x7F;
446 if (!(events = via2[gIFR] & mask)) return;
447
448 for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
449 if (events & irq_bit) {
450 via2[gIER] = irq_bit;
451 mac_do_irq_list(VIA2_SOURCE_BASE + i, regs);
452 via2[gIFR] = irq_bit | rbv_clear;
453 via2[gIER] = irq_bit | 0x80;
454 }
455 }
456
457 /*
458 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
459 * VIA2 dispatcher as a fast interrupt handler.
460 */
461
462 void via_nubus_irq(int irq, void *dev_id, struct pt_regs *regs)
463 {
464 int irq_bit, i;
465 unsigned char events;
466
467 if (!(events = ~via2[gBufA] & nubus_active)) return;
468
469 for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1) {
470 if (events & irq_bit) {
471 via_irq_disable(NUBUS_SOURCE_BASE + i);
472 mac_do_irq_list(NUBUS_SOURCE_BASE + i, regs);
473 via_irq_enable(NUBUS_SOURCE_BASE + i);
474 }
475 }
476 }
477
478 void via_irq_enable(int irq) {
479 int irq_src = IRQ_SRC(irq);
480 int irq_idx = IRQ_IDX(irq);
481 int irq_bit = 1 << irq_idx;
482
483 #ifdef DEBUG_IRQUSE
484 printk("via_irq_enable(%d)\n", irq);
485 #endif
486
487 if (irq_src == 1) {
488 via1[vIER] = irq_bit | 0x80;
489 } else if (irq_src == 2) {
490 /*
491 * Set vPCR for SCSI interrupts (but not on RBV)
492 */
493 if ((irq_idx == 0) && !rbv_present) {
494 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
495 /* CB2 (IRQ) indep. input, positive edge */
496 /* CA2 (DRQ) indep. input, positive edge */
497 via2[vPCR] = 0x66;
498 } else {
499 /* CB2 (IRQ) indep. input, negative edge */
500 /* CA2 (DRQ) indep. input, negative edge */
501 via2[vPCR] = 0x22;
502 }
503 }
504 via2[gIER] = irq_bit | 0x80;
505 } else if (irq_src == 7) {
506 if (rbv_present) {
507 /* enable the slot interrupt. SIER works like IER. */
508 via2[rSIER] = IER_SET_BIT(irq_idx);
509 } else {
510 /* Make sure the bit is an input, to enable the irq */
511 via2[vDirA] &= ~irq_bit;
512 }
513 nubus_active |= irq_bit;
514 }
515 }
516
517 void via_irq_disable(int irq) {
518 int irq_src = IRQ_SRC(irq);
519 int irq_idx = IRQ_IDX(irq);
520 int irq_bit = 1 << irq_idx;
521
522 #ifdef DEBUG_IRQUSE
523 printk("via_irq_disable(%d)\n", irq);
524 #endif
525
526 if (irq_src == 1) {
527 via1[vIER] = irq_bit;
528 } else if (irq_src == 2) {
529 via2[gIER] = irq_bit;
530 } else if (irq_src == 7) {
531 if (rbv_present) {
532 /* disable the slot interrupt. SIER works like IER. */
533 via2[rSIER] = IER_CLR_BIT(irq_idx);
534 } else {
535 /* disable the nubus irq by changing dir to output */
536 via2[vDirA] |= irq_bit;
537 }
538 nubus_active &= ~irq_bit;
539 }
540 }
541
542 void via_irq_clear(int irq) {
543 int irq_src = IRQ_SRC(irq);
544 int irq_idx = IRQ_IDX(irq);
545 int irq_bit = 1 << irq_idx;
546
547 if (irq_src == 1) {
548 via1[vIFR] = irq_bit;
549 } else if (irq_src == 2) {
550 via2[gIFR] = irq_bit | rbv_clear;
551 } else if (irq_src == 7) {
552 /* FIXME: hmm.. */
553 }
554 }
555
556 /*
557 * Returns nonzero if an interrupt is pending on the given
558 * VIA/IRQ combination.
559 */
560
561 int via_irq_pending(int irq)
562 {
563 int irq_src = IRQ_SRC(irq);
564 int irq_idx = IRQ_IDX(irq);
565 int irq_bit = 1 << irq_idx;
566
567 if (irq_src == 1) {
568 return via1[vIFR] & irq_bit;
569 } else if (irq_src == 2) {
570 return via2[gIFR] & irq_bit;
571 } else if (irq_src == 7) {
572 return ~via2[gBufA] & irq_bit;
573 }
574 return 0;
575 }
576