2 * 6522 Versatile Interface Adapter (VIA)
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.
7 * CSA: Motorola seems to have removed documentation on the 6522 from
9 * http://nerini.drf.com/vectrex/other/text/chips/6522/
10 * http://www.zymurgy.net/classic/vic20/vicdet1.htm
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
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
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)
25 #include <linux/types.h>
26 #include <linux/kernel.h>
28 #include <linux/delay.h>
29 #include <linux/init.h>
30 #include <linux/ide.h>
31 #include <linux/module.h>
33 #include <asm/bootinfo.h>
34 #include <asm/macintosh.h>
35 #include <asm/macints.h>
36 #include <asm/machw.h>
37 #include <asm/mac_via.h>
38 #include <asm/mac_psc.h>
40 volatile __u8 *via1, *via2;
42 /* See note in mac_via.h about how this is possibly not useful */
43 volatile long *via_memory_bogon=(long *)&via_memory_bogon;
47 EXPORT_SYMBOL(via_alt_mapping);
51 * Globals for accessing the VIA chip registers without having to
52 * check if we're hitting a real VIA or an RBV. Normally you could
53 * just hit the combined register (ie, vIER|rIER) but that seems to
54 * break on AV Macs...probably because they actually decode more than
55 * eight address bits. Why can't Apple engineers at least be
56 * _consistently_ lazy? - 1999-05-21 (jmt)
59 static int gIER,gIFR,gBufA,gBufB;
65 #define TICK_SIZE 10000
66 #define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */
67 #define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF)
68 #define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8)
70 /* To disable a NuBus slot on Quadras we make the slot IRQ lines outputs, set
71 * high. On RBV we just use the slot interrupt enable register. On Macs with
72 * genuine VIA chips we must use nubus_disabled to keep track of disabled slot
73 * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
74 * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
75 * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
76 * because closing one of those drivers can mask all of the NuBus interrupts.
77 * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
78 * possible to get interrupts from cards that MacOS or the ROM has configured
79 * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
80 * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
82 static u8 nubus_disabled;
84 void via_debug_dump(void);
85 irqreturn_t via1_irq(int, void *);
86 irqreturn_t via2_irq(int, void *);
87 irqreturn_t via_nubus_irq(int, void *);
88 void via_irq_enable(int irq);
89 void via_irq_disable(int irq);
90 void via_irq_clear(int irq);
92 extern irqreturn_t mac_scc_dispatch(int, void *);
93 extern int oss_present;
98 * First we figure out where they actually _are_ as well as what type of
99 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
100 * Then we pretty much clear them out and disable all IRQ sources.
102 * Note: the OSS is actually "detected" here and not in oss_init(). It just
103 * seems more logical to do it here since via_init() needs to know
104 * these things anyways.
107 void __init via_init(void)
109 switch(macintosh_config->via_type) {
111 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
114 via1 = (void *) VIA1_BASE;
115 if (macintosh_config->ident == MAC_MODEL_IIFX) {
120 via2 = (void *) RBV_BASE;
124 if (macintosh_config->ident == MAC_MODEL_LCIII) {
127 /* on most RBVs (& unlike the VIAs), you */
128 /* need to set bit 7 when you write to IFR */
129 /* in order for your clear to occur. */
138 /* Quadra and early MacIIs agree on the VIA locations */
142 via1 = (void *) VIA1_BASE;
143 via2 = (void *) VIA2_BASE;
153 panic("UNKNOWN VIA TYPE");
156 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
158 printk(KERN_INFO "VIA2 at %p is ", via2);
161 } else if (oss_present) {
164 printk("a 6522 or clone\n");
172 * Shut down all IRQ sources, reset the timers, and
173 * kill the timer latch on VIA1.
185 via1[vACR] &= ~0x03; /* disable port A & B latches */
188 * SE/30: disable video IRQ
189 * XXX: testing for SE/30 VBL
192 if (macintosh_config->ident == MAC_MODEL_SE30) {
198 * Set the RTC bits to a known state: all lines to outputs and
199 * RTC disabled (yes that's 0 to enable and 1 to disable).
202 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
203 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
205 /* Everything below this point is VIA2/RBV only... */
207 if (oss_present) return;
210 /* Some machines support an alternate IRQ mapping that spreads */
211 /* Ethernet and Sound out to their own autolevel IRQs and moves */
212 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
213 /* that the IIfx emulates this alternate mapping using the OSS. */
215 switch(macintosh_config->ident) {
217 case MAC_MODEL_P475F:
220 case MAC_MODEL_Q605_ACC:
232 via1[vBufB] &= ~0x40;
243 * Now initialize VIA2. For RBV we just kill all interrupts;
244 * for a regular VIA we also reset the timers and stuff.
248 via2[gIFR] = 0x7F | rbv_clear;
257 via2[vACR] &= ~0x03; /* disable port A & B latches */
261 * Set vPCR for SCSI interrupts (but not on RBV)
264 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
265 /* CB2 (IRQ) indep. input, positive edge */
266 /* CA2 (DRQ) indep. input, positive edge */
269 /* CB2 (IRQ) indep. input, negative edge */
270 /* CA2 (DRQ) indep. input, negative edge */
277 * Start the 100 Hz clock
280 void __init via_init_clock(irq_handler_t func)
283 via1[vT1LL] = MAC_CLOCK_LOW;
284 via1[vT1LH] = MAC_CLOCK_HIGH;
285 via1[vT1CL] = MAC_CLOCK_LOW;
286 via1[vT1CH] = MAC_CLOCK_HIGH;
288 request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
292 * Register the interrupt dispatchers for VIA or RBV machines only.
295 void __init via_register_interrupts(void)
297 if (via_alt_mapping) {
298 request_irq(IRQ_AUTO_1, via1_irq,
299 IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
301 request_irq(IRQ_AUTO_6, via1_irq,
302 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
305 request_irq(IRQ_AUTO_1, via1_irq,
306 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
309 request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
310 "via2", (void *) via2);
312 request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
313 "scc", mac_scc_dispatch);
315 request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
316 "nubus", (void *) via2);
320 * Debugging dump, used in various places to see what's going on.
323 void via_debug_dump(void)
325 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
326 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
327 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
328 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
330 printk(KERN_DEBUG "VIA2: <OSS>\n");
331 } else if (rbv_present) {
332 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
333 (uint) via2[rIFR], (uint) via2[rIER]);
334 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
335 (uint) via2[rSIFR], (uint) via2[rSIER]);
337 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
338 (uint) via2[vDirA], (uint) via2[vDirB],
340 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
342 (uint) via2[vIFR], (uint) via2[vIER]);
347 * This is always executed with interrupts disabled.
349 * TBI: get time offset between scheduling timer ticks
352 unsigned long mac_gettimeoffset (void)
354 unsigned long ticks, offset = 0;
356 /* read VIA1 timer 2 current value */
357 ticks = via1[vT1CL] | (via1[vT1CH] << 8);
358 /* The probability of underflow is less than 2% */
359 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
360 /* Check for pending timer interrupt in VIA1 IFR */
361 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
363 ticks = MAC_CLOCK_TICK - ticks;
364 ticks = ticks * 10000L / MAC_CLOCK_TICK;
366 return ticks + offset;
370 * Flush the L2 cache on Macs that have it by flipping
371 * the system into 24-bit mode for an instant.
374 void via_flush_cache(void)
376 via2[gBufB] &= ~VIA2B_vMode32;
377 via2[gBufB] |= VIA2B_vMode32;
381 * Return the status of the L2 cache on a IIci
384 int via_get_cache_disable(void)
386 /* Safeguard against being called accidentally */
388 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
392 return (int) via2[gBufB] & VIA2B_vCDis;
396 * Initialize VIA2 for Nubus access
399 void __init via_nubus_init(void)
401 /* unlock nubus transactions */
403 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
404 (macintosh_config->adb_type != MAC_ADB_PB2)) {
405 /* set the line to be an output on non-RBV machines */
409 /* this seems to be an ADB bit on PMU machines */
410 /* according to MkLinux. -- jmt */
414 /* Disable all the slot interrupts (where possible). */
416 switch (macintosh_config->via_type) {
418 /* Just make the port A lines inputs. */
419 switch(macintosh_config->ident) {
424 /* The top two bits are RAM size outputs. */
432 /* RBV. Disable all the slot interrupts. SIER works like IER. */
436 /* Disable the inactive slot interrupts by making those lines outputs. */
437 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
438 (macintosh_config->adb_type != MAC_ADB_PB2)) {
447 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
448 * via6522.c :-), disable/pending masks added.
451 irqreturn_t via1_irq(int irq, void *dev_id)
454 unsigned char irq_bit, events;
456 events = via1[vIFR] & via1[vIER] & 0x7F;
460 irq_num = VIA1_SOURCE_BASE;
463 if (events & irq_bit) {
464 via1[vIFR] = irq_bit;
465 m68k_handle_int(irq_num);
469 } while (events >= irq_bit);
471 #if 0 /* freakin' pmu is doing weird stuff */
473 /* This (still) seems to be necessary to get IDE
474 working. However, if you enable VBL interrupts,
476 /* FIXME: should we check the SLOTIRQ bit before
477 pulling this stunt? */
478 /* No, it won't be set. that's why we're doing this. */
479 via_irq_disable(IRQ_MAC_NUBUS);
480 via_irq_clear(IRQ_MAC_NUBUS);
481 m68k_handle_int(IRQ_MAC_NUBUS);
482 via_irq_enable(IRQ_MAC_NUBUS);
488 irqreturn_t via2_irq(int irq, void *dev_id)
491 unsigned char irq_bit, events;
493 events = via2[gIFR] & via2[gIER] & 0x7F;
497 irq_num = VIA2_SOURCE_BASE;
500 if (events & irq_bit) {
501 via2[gIFR] = irq_bit | rbv_clear;
502 m68k_handle_int(irq_num);
506 } while (events >= irq_bit);
511 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
512 * VIA2 dispatcher as a fast interrupt handler.
515 irqreturn_t via_nubus_irq(int irq, void *dev_id)
518 unsigned char slot_bit, events;
520 events = ~via2[gBufA] & 0x7F;
522 events &= via2[rSIER];
524 events &= ~via2[vDirA];
529 slot_irq = IRQ_NUBUS_F;
532 if (events & slot_bit) {
534 m68k_handle_int(slot_irq);
540 /* clear the CA1 interrupt and make certain there's no more. */
541 via2[gIFR] = 0x02 | rbv_clear;
542 events = ~via2[gBufA] & 0x7F;
544 events &= via2[rSIER];
546 events &= ~via2[vDirA];
551 void via_irq_enable(int irq) {
552 int irq_src = IRQ_SRC(irq);
553 int irq_idx = IRQ_IDX(irq);
556 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
560 via1[vIER] = IER_SET_BIT(irq_idx);
561 } else if (irq_src == 2) {
562 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
563 via2[gIER] = IER_SET_BIT(irq_idx);
564 } else if (irq_src == 7) {
565 switch (macintosh_config->via_type) {
567 nubus_disabled &= ~(1 << irq_idx);
568 /* Enable the CA1 interrupt when no slot is disabled. */
570 via2[gIER] = IER_SET_BIT(1);
573 /* On RBV, enable the slot interrupt.
574 * SIER works like IER.
576 via2[rSIER] = IER_SET_BIT(irq_idx);
579 /* Make the port A line an input to enable the slot irq.
580 * But not on PowerBooks, that's ADB.
582 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
583 (macintosh_config->adb_type != MAC_ADB_PB2))
584 via2[vDirA] &= ~(1 << irq_idx);
590 void via_irq_disable(int irq) {
591 int irq_src = IRQ_SRC(irq);
592 int irq_idx = IRQ_IDX(irq);
595 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
599 via1[vIER] = IER_CLR_BIT(irq_idx);
600 } else if (irq_src == 2) {
601 via2[gIER] = IER_CLR_BIT(irq_idx);
602 } else if (irq_src == 7) {
603 switch (macintosh_config->via_type) {
605 nubus_disabled |= 1 << irq_idx;
607 via2[gIER] = IER_CLR_BIT(1);
610 via2[rSIER] = IER_CLR_BIT(irq_idx);
613 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
614 (macintosh_config->adb_type != MAC_ADB_PB2))
615 via2[vDirA] |= 1 << irq_idx;
621 void via_irq_clear(int irq) {
622 int irq_src = IRQ_SRC(irq);
623 int irq_idx = IRQ_IDX(irq);
624 int irq_bit = 1 << irq_idx;
627 via1[vIFR] = irq_bit;
628 } else if (irq_src == 2) {
629 via2[gIFR] = irq_bit | rbv_clear;
630 } else if (irq_src == 7) {
631 /* FIXME: There is no way to clear an individual nubus slot
632 * IRQ flag, other than getting the device to do it.
638 * Returns nonzero if an interrupt is pending on the given
639 * VIA/IRQ combination.
642 int via_irq_pending(int irq)
644 int irq_src = IRQ_SRC(irq);
645 int irq_idx = IRQ_IDX(irq);
646 int irq_bit = 1 << irq_idx;
649 return via1[vIFR] & irq_bit;
650 } else if (irq_src == 2) {
651 return via2[gIFR] & irq_bit;
652 } else if (irq_src == 7) {
653 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
654 return ~via2[gBufA] & irq_bit;