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/module.h>
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>
39 volatile __u8 *via1, *via2;
42 EXPORT_SYMBOL(via_alt_mapping);
43 static __u8 rbv_clear;
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)
54 static int gIER,gIFR,gBufA,gBufB;
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)
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.
77 static u8 nubus_disabled;
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);
87 extern irqreturn_t mac_scc_dispatch(int, void *);
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.
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.
101 void __init via_init(void)
103 switch(macintosh_config->via_type) {
105 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
108 via1 = (void *) VIA1_BASE;
109 if (macintosh_config->ident == MAC_MODEL_IIFX) {
114 via2 = (void *) RBV_BASE;
118 if (macintosh_config->ident == MAC_MODEL_LCIII) {
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. */
132 /* Quadra and early MacIIs agree on the VIA locations */
136 via1 = (void *) VIA1_BASE;
137 via2 = (void *) VIA2_BASE;
147 panic("UNKNOWN VIA TYPE");
150 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
152 printk(KERN_INFO "VIA2 at %p is ", via2);
155 } else if (oss_present) {
158 printk("a 6522 or clone\n");
166 * Shut down all IRQ sources, reset the timers, and
167 * kill the timer latch on VIA1.
178 via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
179 via1[vACR] &= ~0x03; /* disable port A & B latches */
182 * SE/30: disable video IRQ
183 * XXX: testing for SE/30 VBL
186 if (macintosh_config->ident == MAC_MODEL_SE30) {
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).
196 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
197 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
199 /* Everything below this point is VIA2/RBV only... */
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. */
210 if (macintosh_config->via_type == MAC_VIA_QUADRA)
211 switch (macintosh_config->ident) {
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:
233 via1[vBufB] &= ~0x40;
238 * Now initialize VIA2. For RBV we just kill all interrupts;
239 * for a regular VIA we also reset the timers and stuff.
243 via2[gIFR] = 0x7F | rbv_clear;
251 via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
252 via2[vACR] &= ~0x03; /* disable port A & B latches */
256 * Set vPCR for control line interrupts (but not on RBV)
259 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
260 * are made negative edge triggered here.
262 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
263 /* CB2 (IRQ) indep. input, positive edge */
264 /* CA2 (DRQ) indep. input, positive edge */
267 /* CB2 (IRQ) indep. input, negative edge */
268 /* CA2 (DRQ) indep. input, negative edge */
275 * Start the 100 Hz clock
278 void __init via_init_clock(irq_handler_t func)
281 via1[vT1LL] = MAC_CLOCK_LOW;
282 via1[vT1LH] = MAC_CLOCK_HIGH;
283 via1[vT1CL] = MAC_CLOCK_LOW;
284 via1[vT1CH] = MAC_CLOCK_HIGH;
286 if (request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func))
287 pr_err("Couldn't register %s interrupt\n", "timer");
291 * Register the interrupt dispatchers for VIA or RBV machines only.
294 void __init via_register_interrupts(void)
296 if (via_alt_mapping) {
297 if (request_irq(IRQ_AUTO_1, via1_irq,
298 IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
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",
304 pr_err("Couldn't register %s interrupt\n", "via1");
306 if (request_irq(IRQ_AUTO_1, via1_irq,
307 IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
309 pr_err("Couldn't register %s interrupt\n", "via1");
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");
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");
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");
325 * Debugging dump, used in various places to see what's going on.
328 void via_debug_dump(void)
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]);
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]);
342 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
343 (uint) via2[vDirA], (uint) via2[vDirB],
345 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
347 (uint) via2[vIFR], (uint) via2[vIER]);
352 * This is always executed with interrupts disabled.
354 * TBI: get time offset between scheduling timer ticks
357 unsigned long mac_gettimeoffset (void)
359 unsigned long ticks, offset = 0;
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;
368 ticks = MAC_CLOCK_TICK - ticks;
369 ticks = ticks * 10000L / MAC_CLOCK_TICK;
371 return ticks + offset;
375 * Flush the L2 cache on Macs that have it by flipping
376 * the system into 24-bit mode for an instant.
379 void via_flush_cache(void)
381 via2[gBufB] &= ~VIA2B_vMode32;
382 via2[gBufB] |= VIA2B_vMode32;
386 * Return the status of the L2 cache on a IIci
389 int via_get_cache_disable(void)
391 /* Safeguard against being called accidentally */
393 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
397 return (int) via2[gBufB] & VIA2B_vCDis;
401 * Initialize VIA2 for Nubus access
404 void __init via_nubus_init(void)
406 /* unlock nubus transactions */
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 */
414 /* this seems to be an ADB bit on PMU machines */
415 /* according to MkLinux. -- jmt */
419 /* Disable all the slot interrupts (where possible). */
421 switch (macintosh_config->via_type) {
423 /* Just make the port A lines inputs. */
424 switch(macintosh_config->ident) {
429 /* The top two bits are RAM size outputs. */
437 /* RBV. Disable all the slot interrupts. SIER works like IER. */
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)) {
452 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
453 * via6522.c :-), disable/pending masks added.
456 irqreturn_t via1_irq(int irq, void *dev_id)
459 unsigned char irq_bit, events;
461 events = via1[vIFR] & via1[vIER] & 0x7F;
465 irq_num = VIA1_SOURCE_BASE;
468 if (events & irq_bit) {
469 via1[vIFR] = irq_bit;
470 m68k_handle_int(irq_num);
474 } while (events >= irq_bit);
478 irqreturn_t via2_irq(int irq, void *dev_id)
481 unsigned char irq_bit, events;
483 events = via2[gIFR] & via2[gIER] & 0x7F;
487 irq_num = VIA2_SOURCE_BASE;
490 if (events & irq_bit) {
491 via2[gIFR] = irq_bit | rbv_clear;
492 m68k_handle_int(irq_num);
496 } while (events >= irq_bit);
501 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
502 * VIA2 dispatcher as a fast interrupt handler.
505 irqreturn_t via_nubus_irq(int irq, void *dev_id)
508 unsigned char slot_bit, events;
510 events = ~via2[gBufA] & 0x7F;
512 events &= via2[rSIER];
514 events &= ~via2[vDirA];
519 slot_irq = IRQ_NUBUS_F;
522 if (events & slot_bit) {
524 m68k_handle_int(slot_irq);
530 /* clear the CA1 interrupt and make certain there's no more. */
531 via2[gIFR] = 0x02 | rbv_clear;
532 events = ~via2[gBufA] & 0x7F;
534 events &= via2[rSIER];
536 events &= ~via2[vDirA];
541 void via_irq_enable(int irq) {
542 int irq_src = IRQ_SRC(irq);
543 int irq_idx = IRQ_IDX(irq);
546 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
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) {
557 nubus_disabled &= ~(1 << irq_idx);
558 /* Enable the CA1 interrupt when no slot is disabled. */
560 via2[gIER] = IER_SET_BIT(1);
563 /* On RBV, enable the slot interrupt.
564 * SIER works like IER.
566 via2[rSIER] = IER_SET_BIT(irq_idx);
569 /* Make the port A line an input to enable the slot irq.
570 * But not on PowerBooks, that's ADB.
572 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
573 (macintosh_config->adb_type != MAC_ADB_PB2))
574 via2[vDirA] &= ~(1 << irq_idx);
580 void via_irq_disable(int irq) {
581 int irq_src = IRQ_SRC(irq);
582 int irq_idx = IRQ_IDX(irq);
585 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
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) {
595 nubus_disabled |= 1 << irq_idx;
597 via2[gIER] = IER_CLR_BIT(1);
600 via2[rSIER] = IER_CLR_BIT(irq_idx);
603 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
604 (macintosh_config->adb_type != MAC_ADB_PB2))
605 via2[vDirA] |= 1 << irq_idx;
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;
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.
628 * Returns nonzero if an interrupt is pending on the given
629 * VIA/IRQ combination.
632 int via_irq_pending(int irq)
634 int irq_src = IRQ_SRC(irq);
635 int irq_idx = IRQ_IDX(irq);
636 int irq_bit = 1 << irq_idx;
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;
649 void via1_set_head(int head)
652 via1[vBufA] &= ~VIA1A_vHeadSel;
654 via1[vBufA] |= VIA1A_vHeadSel;
656 EXPORT_SYMBOL(via1_set_head);