xref: /linux/arch/m68k/mac/via.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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 #include <linux/ide.h>
27 
28 #include <asm/bootinfo.h>
29 #include <asm/macintosh.h>
30 #include <asm/macints.h>
31 #include <asm/machw.h>
32 #include <asm/mac_via.h>
33 #include <asm/mac_psc.h>
34 
35 volatile __u8 *via1, *via2;
36 #if 0
37 /* See note in mac_via.h about how this is possibly not useful */
38 volatile long *via_memory_bogon=(long *)&via_memory_bogon;
39 #endif
40 int  rbv_present,via_alt_mapping;
41 __u8 rbv_clear;
42 
43 /*
44  * Globals for accessing the VIA chip registers without having to
45  * check if we're hitting a real VIA or an RBV. Normally you could
46  * just hit the combined register (ie, vIER|rIER) but that seems to
47  * break on AV Macs...probably because they actually decode more than
48  * eight address bits. Why can't Apple engineers at least be
49  * _consistently_ lazy?                          - 1999-05-21 (jmt)
50  */
51 
52 static int gIER,gIFR,gBufA,gBufB;
53 
54 /*
55  * Timer defs.
56  */
57 
58 #define TICK_SIZE		10000
59 #define MAC_CLOCK_TICK		(783300/HZ)		/* ticks per HZ */
60 #define MAC_CLOCK_LOW		(MAC_CLOCK_TICK&0xFF)
61 #define MAC_CLOCK_HIGH		(MAC_CLOCK_TICK>>8)
62 
63 static int  nubus_active;
64 
65 void via_debug_dump(void);
66 irqreturn_t via1_irq(int, void *, struct pt_regs *);
67 irqreturn_t via2_irq(int, void *, struct pt_regs *);
68 irqreturn_t via_nubus_irq(int, void *, struct pt_regs *);
69 void via_irq_enable(int irq);
70 void via_irq_disable(int irq);
71 void via_irq_clear(int irq);
72 
73 extern irqreturn_t mac_scc_dispatch(int, void *, struct pt_regs *);
74 extern int oss_present;
75 
76 /*
77  * Initialize the VIAs
78  *
79  * First we figure out where they actually _are_ as well as what type of
80  * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
81  * Then we pretty much clear them out and disable all IRQ sources.
82  *
83  * Note: the OSS is actually "detected" here and not in oss_init(). It just
84  *	 seems more logical to do it here since via_init() needs to know
85  *	 these things anyways.
86  */
87 
88 void __init via_init(void)
89 {
90 	switch(macintosh_config->via_type) {
91 
92 		/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
93 
94 		case MAC_VIA_IIci:
95 			via1 = (void *) VIA1_BASE;
96 			if (macintosh_config->ident == MAC_MODEL_IIFX) {
97 				via2 = NULL;
98 				rbv_present = 0;
99 				oss_present = 1;
100 			} else {
101 				via2 = (void *) RBV_BASE;
102 				rbv_present = 1;
103 				oss_present = 0;
104 			}
105 			if (macintosh_config->ident == MAC_MODEL_LCIII) {
106 				rbv_clear = 0x00;
107 			} else {
108 				/* on most RBVs (& unlike the VIAs), you   */
109 				/* need to set bit 7 when you write to IFR */
110 				/* in order for your clear to occur.       */
111 				rbv_clear = 0x80;
112 			}
113 			gIER = rIER;
114 			gIFR = rIFR;
115 			gBufA = rSIFR;
116 			gBufB = rBufB;
117 			break;
118 
119 		/* Quadra and early MacIIs agree on the VIA locations */
120 
121 		case MAC_VIA_QUADRA:
122 		case MAC_VIA_II:
123 			via1 = (void *) VIA1_BASE;
124 			via2 = (void *) VIA2_BASE;
125 			rbv_present = 0;
126 			oss_present = 0;
127 			rbv_clear = 0x00;
128 			gIER = vIER;
129 			gIFR = vIFR;
130 			gBufA = vBufA;
131 			gBufB = vBufB;
132 			break;
133 		default:
134 			panic("UNKNOWN VIA TYPE");
135 	}
136 
137 	printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
138 
139 	printk(KERN_INFO "VIA2 at %p is ", via2);
140 	if (rbv_present) {
141 		printk(KERN_INFO "an RBV\n");
142 	} else if (oss_present) {
143 		printk(KERN_INFO "an OSS\n");
144 	} else {
145 		printk(KERN_INFO "a 6522 or clone\n");
146 	}
147 
148 #ifdef DEBUG_VIA
149 	via_debug_dump();
150 #endif
151 
152 	/*
153 	 * Shut down all IRQ sources, reset the timers, and
154 	 * kill the timer latch on VIA1.
155 	 */
156 
157 	via1[vIER] = 0x7F;
158 	via1[vIFR] = 0x7F;
159 	via1[vT1LL] = 0;
160 	via1[vT1LH] = 0;
161 	via1[vT1CL] = 0;
162 	via1[vT1CH] = 0;
163 	via1[vT2CL] = 0;
164 	via1[vT2CH] = 0;
165 	via1[vACR] &= 0x3F;
166 
167 	/*
168 	 * SE/30: disable video IRQ
169 	 * XXX: testing for SE/30 VBL
170 	 */
171 
172 	if (macintosh_config->ident == MAC_MODEL_SE30) {
173 		via1[vDirB] |= 0x40;
174 		via1[vBufB] |= 0x40;
175 	}
176 
177 	/*
178 	 * Set the RTC bits to a known state: all lines to outputs and
179 	 * RTC disabled (yes that's 0 to enable and 1 to disable).
180 	 */
181 
182 	via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
183 	via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
184 
185 	/* Everything below this point is VIA2/RBV only... */
186 
187 	if (oss_present) return;
188 
189 #if 1
190 	/* Some machines support an alternate IRQ mapping that spreads  */
191 	/* Ethernet and Sound out to their own autolevel IRQs and moves */
192 	/* VIA1 to level 6. A/UX uses this mapping and we do too.  Note */
193 	/* that the IIfx emulates this alternate mapping using the OSS. */
194 
195 	switch(macintosh_config->ident) {
196 		case MAC_MODEL_C610:
197 		case MAC_MODEL_Q610:
198 		case MAC_MODEL_C650:
199 		case MAC_MODEL_Q650:
200 		case MAC_MODEL_Q700:
201 		case MAC_MODEL_Q800:
202 		case MAC_MODEL_Q900:
203 		case MAC_MODEL_Q950:
204 			via_alt_mapping = 1;
205 			via1[vDirB] |= 0x40;
206 			via1[vBufB] &= ~0x40;
207 			break;
208 		default:
209 			via_alt_mapping = 0;
210 			break;
211 	}
212 #else
213 	via_alt_mapping = 0;
214 #endif
215 
216 	/*
217 	 * Now initialize VIA2. For RBV we just kill all interrupts;
218 	 * for a regular VIA we also reset the timers and stuff.
219 	 */
220 
221 	via2[gIER] = 0x7F;
222 	via2[gIFR] = 0x7F | rbv_clear;
223 	if (!rbv_present) {
224 		via2[vT1LL] = 0;
225 		via2[vT1LH] = 0;
226 		via2[vT1CL] = 0;
227 		via2[vT1CH] = 0;
228 		via2[vT2CL] = 0;
229 		via2[vT2CH] = 0;
230 		via2[vACR] &= 0x3F;
231 	}
232 }
233 
234 /*
235  * Start the 100 Hz clock
236  */
237 
238 void __init via_init_clock(irqreturn_t (*func)(int, void *, struct pt_regs *))
239 {
240 	via1[vACR] |= 0x40;
241 	via1[vT1LL] = MAC_CLOCK_LOW;
242 	via1[vT1LH] = MAC_CLOCK_HIGH;
243 	via1[vT1CL] = MAC_CLOCK_LOW;
244 	via1[vT1CH] = MAC_CLOCK_HIGH;
245 
246 	request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
247 }
248 
249 /*
250  * Register the interrupt dispatchers for VIA or RBV machines only.
251  */
252 
253 void __init via_register_interrupts(void)
254 {
255 	if (via_alt_mapping) {
256 		request_irq(IRQ_AUTO_1, via1_irq,
257 				IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
258 				(void *) via1);
259 		request_irq(IRQ_AUTO_6, via1_irq,
260 				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
261 				(void *) via1);
262 	} else {
263 		request_irq(IRQ_AUTO_1, via1_irq,
264 				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
265 				(void *) via1);
266 	}
267 	request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
268 			"via2", (void *) via2);
269 	if (!psc_present) {
270 		request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
271 				"scc", mac_scc_dispatch);
272 	}
273 	request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
274 			"nubus", (void *) via2);
275 }
276 
277 /*
278  * Debugging dump, used in various places to see what's going on.
279  */
280 
281 void via_debug_dump(void)
282 {
283 	printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
284 		(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
285 	printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
286 		(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
287 	if (oss_present) {
288 		printk(KERN_DEBUG "VIA2: <OSS>\n");
289 	} else if (rbv_present) {
290 		printk(KERN_DEBUG "VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
291 			(uint) via2[rIFR], (uint) via2[rIER]);
292 		printk(KERN_DEBUG "      SIFR = 0x%02X SIER = 0x%02X\n",
293 			(uint) via2[rSIFR], (uint) via2[rSIER]);
294 	} else {
295 		printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
296 			(uint) via2[vDirA], (uint) via2[vDirB],
297 			(uint) via2[vACR]);
298 		printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
299 			(uint) via2[vPCR],
300 			(uint) via2[vIFR], (uint) via2[vIER]);
301 	}
302 }
303 
304 /*
305  * This is always executed with interrupts disabled.
306  *
307  * TBI: get time offset between scheduling timer ticks
308  */
309 
310 unsigned long mac_gettimeoffset (void)
311 {
312 	unsigned long ticks, offset = 0;
313 
314 	/* read VIA1 timer 2 current value */
315 	ticks = via1[vT1CL] | (via1[vT1CH] << 8);
316 	/* The probability of underflow is less than 2% */
317 	if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
318 		/* Check for pending timer interrupt in VIA1 IFR */
319 		if (via1[vIFR] & 0x40) offset = TICK_SIZE;
320 
321 	ticks = MAC_CLOCK_TICK - ticks;
322 	ticks = ticks * 10000L / MAC_CLOCK_TICK;
323 
324 	return ticks + offset;
325 }
326 
327 /*
328  * Flush the L2 cache on Macs that have it by flipping
329  * the system into 24-bit mode for an instant.
330  */
331 
332 void via_flush_cache(void)
333 {
334 	via2[gBufB] &= ~VIA2B_vMode32;
335 	via2[gBufB] |= VIA2B_vMode32;
336 }
337 
338 /*
339  * Return the status of the L2 cache on a IIci
340  */
341 
342 int via_get_cache_disable(void)
343 {
344 	/* Safeguard against being called accidentally */
345 	if (!via2) {
346 		printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
347 		return 1;
348 	}
349 
350 	return (int) via2[gBufB] & VIA2B_vCDis;
351 }
352 
353 /*
354  * Initialize VIA2 for Nubus access
355  */
356 
357 void __init via_nubus_init(void)
358 {
359 	/* don't set nubus_active = 0 here, it kills the Baboon */
360 	/* interrupt that we've already registered.		*/
361 
362 	/* unlock nubus transactions */
363 
364 	if (!rbv_present) {
365 		/* set the line to be an output on non-RBV machines */
366 		if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
367 		   (macintosh_config->adb_type != MAC_ADB_PB2)) {
368 			via2[vDirB] |= 0x02;
369 		}
370 	}
371 
372 	/* this seems to be an ADB bit on PMU machines */
373 	/* according to MkLinux.  -- jmt               */
374 
375 	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
376 	    (macintosh_config->adb_type != MAC_ADB_PB2)) {
377 		via2[gBufB] |= 0x02;
378 	}
379 
380 	/* disable nubus slot interrupts. */
381 	if (rbv_present) {
382 		via2[rSIER] = 0x7F;
383 		via2[rSIER] = nubus_active | 0x80;
384 	} else {
385 		/* These are ADB bits on PMU */
386 		if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
387 		   (macintosh_config->adb_type != MAC_ADB_PB2)) {
388 			switch(macintosh_config->ident)
389 			{
390 				case MAC_MODEL_II:
391 				case MAC_MODEL_IIX:
392 				case MAC_MODEL_IICX:
393 				case MAC_MODEL_SE30:
394 					via2[vBufA] |= 0x3F;
395 					via2[vDirA] = ~nubus_active | 0xc0;
396 					break;
397 				default:
398 					via2[vBufA] = 0xFF;
399 					via2[vDirA] = ~nubus_active;
400 			}
401 		}
402 	}
403 }
404 
405 /*
406  * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
407  * via6522.c :-), disable/pending masks added.
408  *
409  * The new interrupt architecture in macints.c takes care of a lot of the
410  * gruntwork for us, including tallying the interrupts and calling the
411  * handlers on the linked list. All we need to do here is basically generate
412  * the machspec interrupt number after clearing the interrupt.
413  */
414 
415 irqreturn_t via1_irq(int irq, void *dev_id, struct pt_regs *regs)
416 {
417 	int irq_bit, i;
418 	unsigned char events, mask;
419 
420 	mask = via1[vIER] & 0x7F;
421 	if (!(events = via1[vIFR] & mask))
422 		return IRQ_NONE;
423 
424 	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
425 		if (events & irq_bit) {
426 			via1[vIER] = irq_bit;
427 			m68k_handle_int(VIA1_SOURCE_BASE + i, regs);
428 			via1[vIFR] = irq_bit;
429 			via1[vIER] = irq_bit | 0x80;
430 		}
431 
432 #if 0 /* freakin' pmu is doing weird stuff */
433 	if (!oss_present) {
434 		/* This (still) seems to be necessary to get IDE
435 		   working.  However, if you enable VBL interrupts,
436 		   you're screwed... */
437 		/* FIXME: should we check the SLOTIRQ bit before
438                    pulling this stunt? */
439 		/* No, it won't be set. that's why we're doing this. */
440 		via_irq_disable(IRQ_MAC_NUBUS);
441 		via_irq_clear(IRQ_MAC_NUBUS);
442 		m68k_handle_int(IRQ_MAC_NUBUS, regs);
443 		via_irq_enable(IRQ_MAC_NUBUS);
444 	}
445 #endif
446 	return IRQ_HANDLED;
447 }
448 
449 irqreturn_t via2_irq(int irq, void *dev_id, struct pt_regs *regs)
450 {
451 	int irq_bit, i;
452 	unsigned char events, mask;
453 
454 	mask = via2[gIER] & 0x7F;
455 	if (!(events = via2[gIFR] & mask))
456 		return IRQ_NONE;
457 
458 	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
459 		if (events & irq_bit) {
460 			via2[gIER] = irq_bit;
461 			via2[gIFR] = irq_bit | rbv_clear;
462 			m68k_handle_int(VIA2_SOURCE_BASE + i, regs);
463 			via2[gIER] = irq_bit | 0x80;
464 		}
465 	return IRQ_HANDLED;
466 }
467 
468 /*
469  * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
470  * VIA2 dispatcher as a fast interrupt handler.
471  */
472 
473 irqreturn_t via_nubus_irq(int irq, void *dev_id, struct pt_regs *regs)
474 {
475 	int irq_bit, i;
476 	unsigned char events;
477 
478 	if (!(events = ~via2[gBufA] & nubus_active))
479 		return IRQ_NONE;
480 
481 	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1) {
482 		if (events & irq_bit) {
483 			via_irq_disable(NUBUS_SOURCE_BASE + i);
484 			m68k_handle_int(NUBUS_SOURCE_BASE + i, regs);
485 			via_irq_enable(NUBUS_SOURCE_BASE + i);
486 		}
487 	}
488 	return IRQ_HANDLED;
489 }
490 
491 void via_irq_enable(int irq) {
492 	int irq_src	= IRQ_SRC(irq);
493 	int irq_idx	= IRQ_IDX(irq);
494 	int irq_bit	= 1 << irq_idx;
495 
496 #ifdef DEBUG_IRQUSE
497 	printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
498 #endif
499 
500 	if (irq_src == 1) {
501 		via1[vIER] = irq_bit | 0x80;
502 	} else if (irq_src == 2) {
503 		/*
504 		 * Set vPCR for SCSI interrupts (but not on RBV)
505 		 */
506 		if ((irq_idx == 0) && !rbv_present) {
507 			if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
508 				/* CB2 (IRQ) indep. input, positive edge */
509 				/* CA2 (DRQ) indep. input, positive edge */
510 				via2[vPCR] = 0x66;
511 			} else {
512 				/* CB2 (IRQ) indep. input, negative edge */
513 				/* CA2 (DRQ) indep. input, negative edge */
514 				via2[vPCR] = 0x22;
515 			}
516 		}
517 		via2[gIER] = irq_bit | 0x80;
518 	} else if (irq_src == 7) {
519 		nubus_active |= irq_bit;
520 		if (rbv_present) {
521 			/* enable the slot interrupt. SIER works like IER. */
522 			via2[rSIER] = IER_SET_BIT(irq_idx);
523 		} else {
524 			/* Make sure the bit is an input, to enable the irq */
525 			/* But not on PowerBooks, that's ADB... */
526 			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
527 			   (macintosh_config->adb_type != MAC_ADB_PB2)) {
528 				switch(macintosh_config->ident)
529 				{
530 					case MAC_MODEL_II:
531 					case MAC_MODEL_IIX:
532 					case MAC_MODEL_IICX:
533 					case MAC_MODEL_SE30:
534 						via2[vDirA] &= (~irq_bit | 0xc0);
535 						break;
536 					default:
537 						via2[vDirA] &= ~irq_bit;
538 				}
539 			}
540 		}
541 	}
542 }
543 
544 void via_irq_disable(int irq) {
545 	int irq_src	= IRQ_SRC(irq);
546 	int irq_idx	= IRQ_IDX(irq);
547 	int irq_bit	= 1 << irq_idx;
548 
549 #ifdef DEBUG_IRQUSE
550 	printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
551 #endif
552 
553 	if (irq_src == 1) {
554 		via1[vIER] = irq_bit;
555 	} else if (irq_src == 2) {
556 		via2[gIER] = irq_bit;
557 	} else if (irq_src == 7) {
558 		if (rbv_present) {
559 			/* disable the slot interrupt.  SIER works like IER. */
560 			via2[rSIER] = IER_CLR_BIT(irq_idx);
561 		} else {
562 			/* disable the nubus irq by changing dir to output */
563 			/* except on PMU */
564 			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
565 			   (macintosh_config->adb_type != MAC_ADB_PB2)) {
566 				via2[vDirA] |= irq_bit;
567 			}
568 		}
569 		nubus_active &= ~irq_bit;
570 	}
571 }
572 
573 void via_irq_clear(int irq) {
574 	int irq_src	= IRQ_SRC(irq);
575 	int irq_idx	= IRQ_IDX(irq);
576 	int irq_bit	= 1 << irq_idx;
577 
578 	if (irq_src == 1) {
579 		via1[vIFR] = irq_bit;
580 	} else if (irq_src == 2) {
581 		via2[gIFR] = irq_bit | rbv_clear;
582 	} else if (irq_src == 7) {
583 		/* FIXME: hmm.. */
584 	}
585 }
586 
587 /*
588  * Returns nonzero if an interrupt is pending on the given
589  * VIA/IRQ combination.
590  */
591 
592 int via_irq_pending(int irq)
593 {
594 	int irq_src	= IRQ_SRC(irq);
595 	int irq_idx	= IRQ_IDX(irq);
596 	int irq_bit	= 1 << irq_idx;
597 
598 	if (irq_src == 1) {
599 		return via1[vIFR] & irq_bit;
600 	} else if (irq_src == 2) {
601 		return via2[gIFR] & irq_bit;
602 	} else if (irq_src == 7) {
603 		return ~via2[gBufA] & irq_bit;
604 	}
605 	return 0;
606 }
607