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>
31 #include <linux/irq.h>
33 #include <asm/bootinfo.h>
34 #include <asm/macintosh.h>
35 #include <asm/macints.h>
36 #include <asm/mac_via.h>
37 #include <asm/mac_psc.h>
38 #include <asm/mac_oss.h>
40 volatile __u8 *via1, *via2;
43 EXPORT_SYMBOL(via_alt_mapping);
44 static __u8 rbv_clear;
47 * Globals for accessing the VIA chip registers without having to
48 * check if we're hitting a real VIA or an RBV. Normally you could
49 * just hit the combined register (ie, vIER|rIER) but that seems to
50 * break on AV Macs...probably because they actually decode more than
51 * eight address bits. Why can't Apple engineers at least be
52 * _consistently_ lazy? - 1999-05-21 (jmt)
55 static int gIER,gIFR,gBufA,gBufB;
61 #define TICK_SIZE 10000
62 #define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */
63 #define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF)
64 #define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8)
66 /* To disable a NuBus slot on Quadras we make that slot IRQ line an output set
67 * high. On RBV we just use the slot interrupt enable register. On Macs with
68 * genuine VIA chips we must use nubus_disabled to keep track of disabled slot
69 * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
70 * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
71 * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
72 * because closing one of those drivers can mask all of the NuBus interrupts.
73 * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
74 * possible to get interrupts from cards that MacOS or the ROM has configured
75 * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
76 * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
78 static u8 nubus_disabled;
80 void via_debug_dump(void);
85 * First we figure out where they actually _are_ as well as what type of
86 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
87 * Then we pretty much clear them out and disable all IRQ sources.
89 * Note: the OSS is actually "detected" here and not in oss_init(). It just
90 * seems more logical to do it here since via_init() needs to know
91 * these things anyways.
94 void __init via_init(void)
96 switch(macintosh_config->via_type) {
98 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
101 via1 = (void *) VIA1_BASE;
102 if (macintosh_config->ident == MAC_MODEL_IIFX) {
107 via2 = (void *) RBV_BASE;
111 if (macintosh_config->ident == MAC_MODEL_LCIII) {
114 /* on most RBVs (& unlike the VIAs), you */
115 /* need to set bit 7 when you write to IFR */
116 /* in order for your clear to occur. */
125 /* Quadra and early MacIIs agree on the VIA locations */
129 via1 = (void *) VIA1_BASE;
130 via2 = (void *) VIA2_BASE;
140 panic("UNKNOWN VIA TYPE");
143 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
145 printk(KERN_INFO "VIA2 at %p is ", via2);
148 } else if (oss_present) {
151 printk("a 6522 or clone\n");
159 * Shut down all IRQ sources, reset the timers, and
160 * kill the timer latch on VIA1.
171 via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
172 via1[vACR] &= ~0x03; /* disable port A & B latches */
175 * SE/30: disable video IRQ
176 * XXX: testing for SE/30 VBL
179 if (macintosh_config->ident == MAC_MODEL_SE30) {
185 * Set the RTC bits to a known state: all lines to outputs and
186 * RTC disabled (yes that's 0 to enable and 1 to disable).
189 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
190 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
192 /* Everything below this point is VIA2/RBV only... */
197 if ((macintosh_config->via_type == MAC_VIA_QUADRA) &&
198 (macintosh_config->adb_type != MAC_ADB_PB1) &&
199 (macintosh_config->adb_type != MAC_ADB_PB2) &&
200 (macintosh_config->ident != MAC_MODEL_C660) &&
201 (macintosh_config->ident != MAC_MODEL_Q840)) {
204 via1[vBufB] &= ~0x40;
210 * Now initialize VIA2. For RBV we just kill all interrupts;
211 * for a regular VIA we also reset the timers and stuff.
215 via2[gIFR] = 0x7F | rbv_clear;
223 via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
224 via2[vACR] &= ~0x03; /* disable port A & B latches */
228 * Set vPCR for control line interrupts (but not on RBV)
231 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
232 * are made negative edge triggered here.
234 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
235 /* CB2 (IRQ) indep. input, positive edge */
236 /* CA2 (DRQ) indep. input, positive edge */
239 /* CB2 (IRQ) indep. input, negative edge */
240 /* CA2 (DRQ) indep. input, negative edge */
247 * Start the 100 Hz clock
250 void __init via_init_clock(irq_handler_t func)
253 via1[vT1LL] = MAC_CLOCK_LOW;
254 via1[vT1LH] = MAC_CLOCK_HIGH;
255 via1[vT1CL] = MAC_CLOCK_LOW;
256 via1[vT1CH] = MAC_CLOCK_HIGH;
258 if (request_irq(IRQ_MAC_TIMER_1, func, 0, "timer", func))
259 pr_err("Couldn't register %s interrupt\n", "timer");
263 * Debugging dump, used in various places to see what's going on.
266 void via_debug_dump(void)
268 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
269 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
270 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
271 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
273 printk(KERN_DEBUG "VIA2: <OSS>\n");
274 } else if (rbv_present) {
275 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
276 (uint) via2[rIFR], (uint) via2[rIER]);
277 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
278 (uint) via2[rSIFR], (uint) via2[rSIER]);
280 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
281 (uint) via2[vDirA], (uint) via2[vDirB],
283 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
285 (uint) via2[vIFR], (uint) via2[vIER]);
290 * This is always executed with interrupts disabled.
292 * TBI: get time offset between scheduling timer ticks
295 unsigned long mac_gettimeoffset (void)
297 unsigned long ticks, offset = 0;
299 /* read VIA1 timer 2 current value */
300 ticks = via1[vT1CL] | (via1[vT1CH] << 8);
301 /* The probability of underflow is less than 2% */
302 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
303 /* Check for pending timer interrupt in VIA1 IFR */
304 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
306 ticks = MAC_CLOCK_TICK - ticks;
307 ticks = ticks * 10000L / MAC_CLOCK_TICK;
309 return ticks + offset;
313 * Flush the L2 cache on Macs that have it by flipping
314 * the system into 24-bit mode for an instant.
317 void via_flush_cache(void)
319 via2[gBufB] &= ~VIA2B_vMode32;
320 via2[gBufB] |= VIA2B_vMode32;
324 * Return the status of the L2 cache on a IIci
327 int via_get_cache_disable(void)
329 /* Safeguard against being called accidentally */
331 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
335 return (int) via2[gBufB] & VIA2B_vCDis;
339 * Initialize VIA2 for Nubus access
342 void __init via_nubus_init(void)
344 /* unlock nubus transactions */
346 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
347 (macintosh_config->adb_type != MAC_ADB_PB2)) {
348 /* set the line to be an output on non-RBV machines */
352 /* this seems to be an ADB bit on PMU machines */
353 /* according to MkLinux. -- jmt */
357 /* Disable all the slot interrupts (where possible). */
359 switch (macintosh_config->via_type) {
361 /* Just make the port A lines inputs. */
362 switch(macintosh_config->ident) {
367 /* The top two bits are RAM size outputs. */
375 /* RBV. Disable all the slot interrupts. SIER works like IER. */
379 /* Disable the inactive slot interrupts by making those lines outputs. */
380 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
381 (macintosh_config->adb_type != MAC_ADB_PB2)) {
390 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
391 * via6522.c :-), disable/pending masks added.
394 void via1_irq(unsigned int irq, struct irq_desc *desc)
397 unsigned char irq_bit, events;
399 events = via1[vIFR] & via1[vIER] & 0x7F;
403 irq_num = VIA1_SOURCE_BASE;
406 if (events & irq_bit) {
407 via1[vIFR] = irq_bit;
408 generic_handle_irq(irq_num);
412 } while (events >= irq_bit);
415 static void via2_irq(unsigned int irq, struct irq_desc *desc)
418 unsigned char irq_bit, events;
420 events = via2[gIFR] & via2[gIER] & 0x7F;
424 irq_num = VIA2_SOURCE_BASE;
427 if (events & irq_bit) {
428 via2[gIFR] = irq_bit | rbv_clear;
429 generic_handle_irq(irq_num);
433 } while (events >= irq_bit);
437 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
438 * VIA2 dispatcher as a fast interrupt handler.
441 void via_nubus_irq(unsigned int irq, struct irq_desc *desc)
444 unsigned char slot_bit, events;
446 events = ~via2[gBufA] & 0x7F;
448 events &= via2[rSIER];
450 events &= ~via2[vDirA];
455 slot_irq = IRQ_NUBUS_F;
458 if (events & slot_bit) {
460 generic_handle_irq(slot_irq);
466 /* clear the CA1 interrupt and make certain there's no more. */
467 via2[gIFR] = 0x02 | rbv_clear;
468 events = ~via2[gBufA] & 0x7F;
470 events &= via2[rSIER];
472 events &= ~via2[vDirA];
477 * Register the interrupt dispatchers for VIA or RBV machines only.
480 void __init via_register_interrupts(void)
482 if (via_alt_mapping) {
483 /* software interrupt */
484 irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
486 irq_set_chained_handler(IRQ_AUTO_6, via1_irq);
488 irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
490 irq_set_chained_handler(IRQ_AUTO_2, via2_irq);
491 irq_set_chained_handler(IRQ_MAC_NUBUS, via_nubus_irq);
494 void via_irq_enable(int irq) {
495 int irq_src = IRQ_SRC(irq);
496 int irq_idx = IRQ_IDX(irq);
499 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
503 via1[vIER] = IER_SET_BIT(irq_idx);
504 } else if (irq_src == 2) {
505 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
506 via2[gIER] = IER_SET_BIT(irq_idx);
507 } else if (irq_src == 7) {
508 switch (macintosh_config->via_type) {
510 nubus_disabled &= ~(1 << irq_idx);
511 /* Enable the CA1 interrupt when no slot is disabled. */
513 via2[gIER] = IER_SET_BIT(1);
516 /* On RBV, enable the slot interrupt.
517 * SIER works like IER.
519 via2[rSIER] = IER_SET_BIT(irq_idx);
522 /* Make the port A line an input to enable the slot irq.
523 * But not on PowerBooks, that's ADB.
525 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
526 (macintosh_config->adb_type != MAC_ADB_PB2))
527 via2[vDirA] &= ~(1 << irq_idx);
533 void via_irq_disable(int irq) {
534 int irq_src = IRQ_SRC(irq);
535 int irq_idx = IRQ_IDX(irq);
538 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
542 via1[vIER] = IER_CLR_BIT(irq_idx);
543 } else if (irq_src == 2) {
544 via2[gIER] = IER_CLR_BIT(irq_idx);
545 } else if (irq_src == 7) {
546 switch (macintosh_config->via_type) {
548 nubus_disabled |= 1 << irq_idx;
550 via2[gIER] = IER_CLR_BIT(1);
553 via2[rSIER] = IER_CLR_BIT(irq_idx);
556 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
557 (macintosh_config->adb_type != MAC_ADB_PB2))
558 via2[vDirA] |= 1 << irq_idx;
564 void via1_set_head(int head)
567 via1[vBufA] &= ~VIA1A_vHeadSel;
569 via1[vBufA] |= VIA1A_vHeadSel;
571 EXPORT_SYMBOL(via1_set_head);
573 int via2_scsi_drq_pending(void)
575 return via2[gIFR] & (1 << IRQ_IDX(IRQ_MAC_SCSIDRQ));
577 EXPORT_SYMBOL(via2_scsi_drq_pending);