xref: /openbmc/linux/arch/m68k/mac/via.c (revision 1da177e4)
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/traps.h>
29 #include <asm/bootinfo.h>
30 #include <asm/macintosh.h>
31 #include <asm/macints.h>
32 #include <asm/machw.h>
33 #include <asm/mac_via.h>
34 #include <asm/mac_psc.h>
35 
36 volatile __u8 *via1, *via2;
37 #if 0
38 /* See note in mac_via.h about how this is possibly not useful */
39 volatile long *via_memory_bogon=(long *)&via_memory_bogon;
40 #endif
41 int  rbv_present,via_alt_mapping;
42 __u8 rbv_clear;
43 
44 /*
45  * Globals for accessing the VIA chip registers without having to
46  * check if we're hitting a real VIA or an RBV. Normally you could
47  * just hit the combined register (ie, vIER|rIER) but that seems to
48  * break on AV Macs...probably because they actually decode more than
49  * eight address bits. Why can't Apple engineers at least be
50  * _consistently_ lazy?                          - 1999-05-21 (jmt)
51  */
52 
53 static int gIER,gIFR,gBufA,gBufB;
54 
55 /*
56  * Timer defs.
57  */
58 
59 #define TICK_SIZE		10000
60 #define MAC_CLOCK_TICK		(783300/HZ)		/* ticks per HZ */
61 #define MAC_CLOCK_LOW		(MAC_CLOCK_TICK&0xFF)
62 #define MAC_CLOCK_HIGH		(MAC_CLOCK_TICK>>8)
63 
64 static int  nubus_active;
65 
66 void via_debug_dump(void);
67 irqreturn_t via1_irq(int, void *, struct pt_regs *);
68 irqreturn_t via2_irq(int, void *, struct pt_regs *);
69 irqreturn_t via_nubus_irq(int, void *, struct pt_regs *);
70 void via_irq_enable(int irq);
71 void via_irq_disable(int irq);
72 void via_irq_clear(int irq);
73 
74 extern irqreturn_t mac_bang(int, void *, struct pt_regs *);
75 extern irqreturn_t mac_scc_dispatch(int, void *, struct pt_regs *);
76 extern int oss_present;
77 
78 /*
79  * Initialize the VIAs
80  *
81  * First we figure out where they actually _are_ as well as what type of
82  * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
83  * Then we pretty much clear them out and disable all IRQ sources.
84  *
85  * Note: the OSS is actually "detected" here and not in oss_init(). It just
86  *	 seems more logical to do it here since via_init() needs to know
87  *	 these things anyways.
88  */
89 
90 void __init via_init(void)
91 {
92 	switch(macintosh_config->via_type) {
93 
94 		/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
95 
96 		case MAC_VIA_IIci:
97 			via1 = (void *) VIA1_BASE;
98 			if (macintosh_config->ident == MAC_MODEL_IIFX) {
99 				via2 = NULL;
100 				rbv_present = 0;
101 				oss_present = 1;
102 			} else {
103 				via2 = (void *) RBV_BASE;
104 				rbv_present = 1;
105 				oss_present = 0;
106 			}
107 			if (macintosh_config->ident == MAC_MODEL_LCIII) {
108 				rbv_clear = 0x00;
109 			} else {
110 				/* on most RBVs (& unlike the VIAs), you   */
111 				/* need to set bit 7 when you write to IFR */
112 				/* in order for your clear to occur.       */
113 				rbv_clear = 0x80;
114 			}
115 			gIER = rIER;
116 			gIFR = rIFR;
117 			gBufA = rSIFR;
118 			gBufB = rBufB;
119 			break;
120 
121 		/* Quadra and early MacIIs agree on the VIA locations */
122 
123 		case MAC_VIA_QUADRA:
124 		case MAC_VIA_II:
125 			via1 = (void *) VIA1_BASE;
126 			via2 = (void *) VIA2_BASE;
127 			rbv_present = 0;
128 			oss_present = 0;
129 			rbv_clear = 0x00;
130 			gIER = vIER;
131 			gIFR = vIFR;
132 			gBufA = vBufA;
133 			gBufB = vBufB;
134 			break;
135 		default:
136 			panic("UNKNOWN VIA TYPE");
137 	}
138 
139 	printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
140 
141 	printk(KERN_INFO "VIA2 at %p is ", via2);
142 	if (rbv_present) {
143 		printk(KERN_INFO "an RBV\n");
144 	} else if (oss_present) {
145 		printk(KERN_INFO "an OSS\n");
146 	} else {
147 		printk(KERN_INFO "a 6522 or clone\n");
148 	}
149 
150 #ifdef DEBUG_VIA
151 	via_debug_dump();
152 #endif
153 
154 	/*
155 	 * Shut down all IRQ sources, reset the timers, and
156 	 * kill the timer latch on VIA1.
157 	 */
158 
159 	via1[vIER] = 0x7F;
160 	via1[vIFR] = 0x7F;
161 	via1[vT1LL] = 0;
162 	via1[vT1LH] = 0;
163 	via1[vT1CL] = 0;
164 	via1[vT1CH] = 0;
165 	via1[vT2CL] = 0;
166 	via1[vT2CH] = 0;
167 	via1[vACR] &= 0x3F;
168 
169 	/*
170 	 * SE/30: disable video IRQ
171 	 * XXX: testing for SE/30 VBL
172 	 */
173 
174 	if (macintosh_config->ident == MAC_MODEL_SE30) {
175 		via1[vDirB] |= 0x40;
176 		via1[vBufB] |= 0x40;
177 	}
178 
179 	/*
180 	 * Set the RTC bits to a known state: all lines to outputs and
181 	 * RTC disabled (yes that's 0 to enable and 1 to disable).
182 	 */
183 
184 	via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
185 	via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
186 
187 	/* Everything below this point is VIA2/RBV only... */
188 
189 	if (oss_present) return;
190 
191 #if 1
192 	/* Some machines support an alternate IRQ mapping that spreads  */
193 	/* Ethernet and Sound out to their own autolevel IRQs and moves */
194 	/* VIA1 to level 6. A/UX uses this mapping and we do too.  Note */
195 	/* that the IIfx emulates this alternate mapping using the OSS. */
196 
197 	switch(macintosh_config->ident) {
198 		case MAC_MODEL_C610:
199 		case MAC_MODEL_Q610:
200 		case MAC_MODEL_C650:
201 		case MAC_MODEL_Q650:
202 		case MAC_MODEL_Q700:
203 		case MAC_MODEL_Q800:
204 		case MAC_MODEL_Q900:
205 		case MAC_MODEL_Q950:
206 			via_alt_mapping = 1;
207 			via1[vDirB] |= 0x40;
208 			via1[vBufB] &= ~0x40;
209 			break;
210 		default:
211 			via_alt_mapping = 0;
212 			break;
213 	}
214 #else
215 	/* The alernate IRQ mapping seems to just not work. Anyone with a   */
216 	/* supported machine is welcome to take a stab at fixing it. It     */
217 	/* _should_ work on the following Quadras: 610,650,700,800,900,950  */
218 	/*                                               - 1999-06-12 (jmt) */
219 
220 	via_alt_mapping = 0;
221 #endif
222 
223 	/*
224 	 * Now initialize VIA2. For RBV we just kill all interrupts;
225 	 * for a regular VIA we also reset the timers and stuff.
226 	 */
227 
228 	via2[gIER] = 0x7F;
229 	via2[gIFR] = 0x7F | rbv_clear;
230 	if (!rbv_present) {
231 		via2[vT1LL] = 0;
232 		via2[vT1LH] = 0;
233 		via2[vT1CL] = 0;
234 		via2[vT1CH] = 0;
235 		via2[vT2CL] = 0;
236 		via2[vT2CH] = 0;
237 		via2[vACR] &= 0x3F;
238 	}
239 }
240 
241 /*
242  * Start the 100 Hz clock
243  */
244 
245 void __init via_init_clock(irqreturn_t (*func)(int, void *, struct pt_regs *))
246 {
247 	via1[vACR] |= 0x40;
248 	via1[vT1LL] = MAC_CLOCK_LOW;
249 	via1[vT1LH] = MAC_CLOCK_HIGH;
250 	via1[vT1CL] = MAC_CLOCK_LOW;
251 	via1[vT1CH] = MAC_CLOCK_HIGH;
252 
253 	request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
254 }
255 
256 /*
257  * Register the interrupt dispatchers for VIA or RBV machines only.
258  */
259 
260 void __init via_register_interrupts(void)
261 {
262 	if (via_alt_mapping) {
263 		cpu_request_irq(IRQ_AUTO_1, via1_irq,
264 				IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
265 				(void *) via1);
266 		cpu_request_irq(IRQ_AUTO_6, via1_irq,
267 				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
268 				(void *) via1);
269 	} else {
270 		cpu_request_irq(IRQ_AUTO_1, via1_irq,
271 				IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
272 				(void *) via1);
273 #if 0 /* interferes with serial on some machines */
274 		if (!psc_present) {
275 			cpu_request_irq(IRQ_AUTO_6, mac_bang, IRQ_FLG_LOCK,
276 					"Off Switch", mac_bang);
277 		}
278 #endif
279 	}
280 	cpu_request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
281 			"via2", (void *) via2);
282 	if (!psc_present) {
283 		cpu_request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
284 				"scc", mac_scc_dispatch);
285 	}
286 	request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
287 			"nubus", (void *) via2);
288 }
289 
290 /*
291  * Debugging dump, used in various places to see what's going on.
292  */
293 
294 void via_debug_dump(void)
295 {
296 	printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
297 		(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
298 	printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
299 		(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
300 	if (oss_present) {
301 		printk(KERN_DEBUG "VIA2: <OSS>\n");
302 	} else if (rbv_present) {
303 		printk(KERN_DEBUG "VIA2:  IFR = 0x%02X  IER = 0x%02X\n",
304 			(uint) via2[rIFR], (uint) via2[rIER]);
305 		printk(KERN_DEBUG "      SIFR = 0x%02X SIER = 0x%02X\n",
306 			(uint) via2[rSIFR], (uint) via2[rSIER]);
307 	} else {
308 		printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
309 			(uint) via2[vDirA], (uint) via2[vDirB],
310 			(uint) via2[vACR]);
311 		printk(KERN_DEBUG "         PCR = 0x%02X  IFR = 0x%02X IER = 0x%02X\n",
312 			(uint) via2[vPCR],
313 			(uint) via2[vIFR], (uint) via2[vIER]);
314 	}
315 }
316 
317 /*
318  * This is always executed with interrupts disabled.
319  *
320  * TBI: get time offset between scheduling timer ticks
321  */
322 
323 unsigned long mac_gettimeoffset (void)
324 {
325 	unsigned long ticks, offset = 0;
326 
327 	/* read VIA1 timer 2 current value */
328 	ticks = via1[vT1CL] | (via1[vT1CH] << 8);
329 	/* The probability of underflow is less than 2% */
330 	if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
331 		/* Check for pending timer interrupt in VIA1 IFR */
332 		if (via1[vIFR] & 0x40) offset = TICK_SIZE;
333 
334 	ticks = MAC_CLOCK_TICK - ticks;
335 	ticks = ticks * 10000L / MAC_CLOCK_TICK;
336 
337 	return ticks + offset;
338 }
339 
340 /*
341  * Flush the L2 cache on Macs that have it by flipping
342  * the system into 24-bit mode for an instant.
343  */
344 
345 void via_flush_cache(void)
346 {
347 	via2[gBufB] &= ~VIA2B_vMode32;
348 	via2[gBufB] |= VIA2B_vMode32;
349 }
350 
351 /*
352  * Return the status of the L2 cache on a IIci
353  */
354 
355 int via_get_cache_disable(void)
356 {
357 	/* Safeguard against being called accidentally */
358 	if (!via2) {
359 		printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
360 		return 1;
361 	}
362 
363 	return (int) via2[gBufB] & VIA2B_vCDis;
364 }
365 
366 /*
367  * Initialize VIA2 for Nubus access
368  */
369 
370 void __init via_nubus_init(void)
371 {
372 	/* don't set nubus_active = 0 here, it kills the Baboon */
373 	/* interrupt that we've already registered.		*/
374 
375 	/* unlock nubus transactions */
376 
377 	if (!rbv_present) {
378 		/* set the line to be an output on non-RBV machines */
379 		if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
380 		   (macintosh_config->adb_type != MAC_ADB_PB2)) {
381 			via2[vDirB] |= 0x02;
382 		}
383 	}
384 
385 	/* this seems to be an ADB bit on PMU machines */
386 	/* according to MkLinux.  -- jmt               */
387 
388 	if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
389 	    (macintosh_config->adb_type != MAC_ADB_PB2)) {
390 		via2[gBufB] |= 0x02;
391 	}
392 
393 	/* disable nubus slot interrupts. */
394 	if (rbv_present) {
395 		via2[rSIER] = 0x7F;
396 		via2[rSIER] = nubus_active | 0x80;
397 	} else {
398 		/* These are ADB bits on PMU */
399 		if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
400 		   (macintosh_config->adb_type != MAC_ADB_PB2)) {
401 			switch(macintosh_config->ident)
402 			{
403 				case MAC_MODEL_II:
404 				case MAC_MODEL_IIX:
405 				case MAC_MODEL_IICX:
406 				case MAC_MODEL_SE30:
407 					via2[vBufA] |= 0x3F;
408 					via2[vDirA] = ~nubus_active | 0xc0;
409 					break;
410 				default:
411 					via2[vBufA] = 0xFF;
412 					via2[vDirA] = ~nubus_active;
413 			}
414 		}
415 	}
416 }
417 
418 /*
419  * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
420  * via6522.c :-), disable/pending masks added.
421  *
422  * The new interrupt architecture in macints.c takes care of a lot of the
423  * gruntwork for us, including tallying the interrupts and calling the
424  * handlers on the linked list. All we need to do here is basically generate
425  * the machspec interrupt number after clearing the interrupt.
426  */
427 
428 irqreturn_t via1_irq(int irq, void *dev_id, struct pt_regs *regs)
429 {
430 	int irq_bit, i;
431 	unsigned char events, mask;
432 
433 	mask = via1[vIER] & 0x7F;
434 	if (!(events = via1[vIFR] & mask))
435 		return IRQ_NONE;
436 
437 	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
438 		if (events & irq_bit) {
439 			via1[vIER] = irq_bit;
440 			mac_do_irq_list(VIA1_SOURCE_BASE + i, regs);
441 			via1[vIFR] = irq_bit;
442 			via1[vIER] = irq_bit | 0x80;
443 		}
444 
445 #if 0 /* freakin' pmu is doing weird stuff */
446 	if (!oss_present) {
447 		/* This (still) seems to be necessary to get IDE
448 		   working.  However, if you enable VBL interrupts,
449 		   you're screwed... */
450 		/* FIXME: should we check the SLOTIRQ bit before
451                    pulling this stunt? */
452 		/* No, it won't be set. that's why we're doing this. */
453 		via_irq_disable(IRQ_MAC_NUBUS);
454 		via_irq_clear(IRQ_MAC_NUBUS);
455 		mac_do_irq_list(IRQ_MAC_NUBUS, regs);
456 		via_irq_enable(IRQ_MAC_NUBUS);
457 	}
458 #endif
459 	return IRQ_HANDLED;
460 }
461 
462 irqreturn_t via2_irq(int irq, void *dev_id, struct pt_regs *regs)
463 {
464 	int irq_bit, i;
465 	unsigned char events, mask;
466 
467 	mask = via2[gIER] & 0x7F;
468 	if (!(events = via2[gIFR] & mask))
469 		return IRQ_NONE;
470 
471 	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
472 		if (events & irq_bit) {
473 			via2[gIER] = irq_bit;
474 			mac_do_irq_list(VIA2_SOURCE_BASE + i, regs);
475 			via2[gIFR] = irq_bit | rbv_clear;
476 			via2[gIER] = irq_bit | 0x80;
477 		}
478 	return IRQ_HANDLED;
479 }
480 
481 /*
482  * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
483  * VIA2 dispatcher as a fast interrupt handler.
484  */
485 
486 irqreturn_t via_nubus_irq(int irq, void *dev_id, struct pt_regs *regs)
487 {
488 	int irq_bit, i;
489 	unsigned char events;
490 
491 	if (!(events = ~via2[gBufA] & nubus_active))
492 		return IRQ_NONE;
493 
494 	for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1) {
495 		if (events & irq_bit) {
496 			via_irq_disable(NUBUS_SOURCE_BASE + i);
497 			mac_do_irq_list(NUBUS_SOURCE_BASE + i, regs);
498 			via_irq_enable(NUBUS_SOURCE_BASE + i);
499 		}
500 	}
501 	return IRQ_HANDLED;
502 }
503 
504 void via_irq_enable(int irq) {
505 	int irq_src	= IRQ_SRC(irq);
506 	int irq_idx	= IRQ_IDX(irq);
507 	int irq_bit	= 1 << irq_idx;
508 
509 #ifdef DEBUG_IRQUSE
510 	printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
511 #endif
512 
513 	if (irq_src == 1) {
514 		via1[vIER] = irq_bit | 0x80;
515 	} else if (irq_src == 2) {
516 		/*
517 		 * Set vPCR for SCSI interrupts (but not on RBV)
518 		 */
519 		if ((irq_idx == 0) && !rbv_present) {
520 			if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
521 				/* CB2 (IRQ) indep. input, positive edge */
522 				/* CA2 (DRQ) indep. input, positive edge */
523 				via2[vPCR] = 0x66;
524 			} else {
525 				/* CB2 (IRQ) indep. input, negative edge */
526 				/* CA2 (DRQ) indep. input, negative edge */
527 				via2[vPCR] = 0x22;
528 			}
529 		}
530 		via2[gIER] = irq_bit | 0x80;
531 	} else if (irq_src == 7) {
532 		if (rbv_present) {
533 			/* enable the slot interrupt. SIER works like IER. */
534 			via2[rSIER] = IER_SET_BIT(irq_idx);
535 		} else {
536 			/* Make sure the bit is an input, to enable the irq */
537 			/* But not on PowerBooks, that's ADB... */
538 			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
539 			   (macintosh_config->adb_type != MAC_ADB_PB2)) {
540 				switch(macintosh_config->ident)
541 				{
542 					case MAC_MODEL_II:
543 					case MAC_MODEL_IIX:
544 					case MAC_MODEL_IICX:
545 					case MAC_MODEL_SE30:
546 						via2[vDirA] &= (~irq_bit | 0xc0);
547 						break;
548 					default:
549 						via2[vDirA] &= ~irq_bit;
550 				}
551 			}
552 		}
553 		nubus_active |= irq_bit;
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 	int irq_bit	= 1 << irq_idx;
561 
562 #ifdef DEBUG_IRQUSE
563 	printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
564 #endif
565 
566 	if (irq_src == 1) {
567 		via1[vIER] = irq_bit;
568 	} else if (irq_src == 2) {
569 		via2[gIER] = irq_bit;
570 	} else if (irq_src == 7) {
571 		if (rbv_present) {
572 			/* disable the slot interrupt.  SIER works like IER. */
573 			via2[rSIER] = IER_CLR_BIT(irq_idx);
574 		} else {
575 			/* disable the nubus irq by changing dir to output */
576 			/* except on PMU */
577 			if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
578 			   (macintosh_config->adb_type != MAC_ADB_PB2)) {
579 				via2[vDirA] |= irq_bit;
580 			}
581 		}
582 		nubus_active &= ~irq_bit;
583 	}
584 }
585 
586 void via_irq_clear(int irq) {
587 	int irq_src	= IRQ_SRC(irq);
588 	int irq_idx	= IRQ_IDX(irq);
589 	int irq_bit	= 1 << irq_idx;
590 
591 	if (irq_src == 1) {
592 		via1[vIFR] = irq_bit;
593 	} else if (irq_src == 2) {
594 		via2[gIFR] = irq_bit | rbv_clear;
595 	} else if (irq_src == 7) {
596 		/* FIXME: hmm.. */
597 	}
598 }
599 
600 /*
601  * Returns nonzero if an interrupt is pending on the given
602  * VIA/IRQ combination.
603  */
604 
605 int via_irq_pending(int irq)
606 {
607 	int irq_src	= IRQ_SRC(irq);
608 	int irq_idx	= IRQ_IDX(irq);
609 	int irq_bit	= 1 << irq_idx;
610 
611 	if (irq_src == 1) {
612 		return via1[vIFR] & irq_bit;
613 	} else if (irq_src == 2) {
614 		return via2[gIFR] & irq_bit;
615 	} else if (irq_src == 7) {
616 		return ~via2[gBufA] & irq_bit;
617 	}
618 	return 0;
619 }
620