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 #ifdef CONFIG_GENERIC_HARDIRQS
32 #include <linux/irq.h>
35 #include <asm/bootinfo.h>
36 #include <asm/macintosh.h>
37 #include <asm/macints.h>
38 #include <asm/mac_via.h>
39 #include <asm/mac_psc.h>
40 #include <asm/mac_oss.h>
42 volatile __u8 *via1, *via2;
45 EXPORT_SYMBOL(via_alt_mapping);
46 static __u8 rbv_clear;
49 * Globals for accessing the VIA chip registers without having to
50 * check if we're hitting a real VIA or an RBV. Normally you could
51 * just hit the combined register (ie, vIER|rIER) but that seems to
52 * break on AV Macs...probably because they actually decode more than
53 * eight address bits. Why can't Apple engineers at least be
54 * _consistently_ lazy? - 1999-05-21 (jmt)
57 static int gIER,gIFR,gBufA,gBufB;
63 #define TICK_SIZE 10000
64 #define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */
65 #define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF)
66 #define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8)
68 /* To disable a NuBus slot on Quadras we make that slot IRQ line an output set
69 * high. On RBV we just use the slot interrupt enable register. On Macs with
70 * genuine VIA chips we must use nubus_disabled to keep track of disabled slot
71 * interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
72 * or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
73 * So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
74 * because closing one of those drivers can mask all of the NuBus interrupts.
75 * Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
76 * possible to get interrupts from cards that MacOS or the ROM has configured
77 * but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
78 * Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
80 static u8 nubus_disabled;
82 void via_debug_dump(void);
83 irqreturn_t via1_irq(int, void *);
84 irqreturn_t via2_irq(int, void *);
85 irqreturn_t via_nubus_irq(int, void *);
86 void via_irq_enable(int irq);
87 void via_irq_disable(int irq);
88 void via_irq_clear(int irq);
93 * First we figure out where they actually _are_ as well as what type of
94 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
95 * Then we pretty much clear them out and disable all IRQ sources.
97 * Note: the OSS is actually "detected" here and not in oss_init(). It just
98 * seems more logical to do it here since via_init() needs to know
99 * these things anyways.
102 void __init via_init(void)
104 switch(macintosh_config->via_type) {
106 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
109 via1 = (void *) VIA1_BASE;
110 if (macintosh_config->ident == MAC_MODEL_IIFX) {
115 via2 = (void *) RBV_BASE;
119 if (macintosh_config->ident == MAC_MODEL_LCIII) {
122 /* on most RBVs (& unlike the VIAs), you */
123 /* need to set bit 7 when you write to IFR */
124 /* in order for your clear to occur. */
133 /* Quadra and early MacIIs agree on the VIA locations */
137 via1 = (void *) VIA1_BASE;
138 via2 = (void *) VIA2_BASE;
148 panic("UNKNOWN VIA TYPE");
151 printk(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
153 printk(KERN_INFO "VIA2 at %p is ", via2);
156 } else if (oss_present) {
159 printk("a 6522 or clone\n");
167 * Shut down all IRQ sources, reset the timers, and
168 * kill the timer latch on VIA1.
179 via1[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
180 via1[vACR] &= ~0x03; /* disable port A & B latches */
183 * SE/30: disable video IRQ
184 * XXX: testing for SE/30 VBL
187 if (macintosh_config->ident == MAC_MODEL_SE30) {
193 * Set the RTC bits to a known state: all lines to outputs and
194 * RTC disabled (yes that's 0 to enable and 1 to disable).
197 via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
198 via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
200 /* Everything below this point is VIA2/RBV only... */
205 /* Some machines support an alternate IRQ mapping that spreads */
206 /* Ethernet and Sound out to their own autolevel IRQs and moves */
207 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
208 /* that the IIfx emulates this alternate mapping using the OSS. */
211 if (macintosh_config->via_type == MAC_VIA_QUADRA)
212 switch (macintosh_config->ident) {
219 case MAC_MODEL_PB140:
220 case MAC_MODEL_PB145:
221 case MAC_MODEL_PB160:
222 case MAC_MODEL_PB165:
223 case MAC_MODEL_PB165C:
224 case MAC_MODEL_PB170:
225 case MAC_MODEL_PB180:
226 case MAC_MODEL_PB180C:
227 case MAC_MODEL_PB190:
228 case MAC_MODEL_PB520:
234 via1[vBufB] &= ~0x40;
239 * Now initialize VIA2. For RBV we just kill all interrupts;
240 * for a regular VIA we also reset the timers and stuff.
244 via2[gIFR] = 0x7F | rbv_clear;
252 via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
253 via2[vACR] &= ~0x03; /* disable port A & B latches */
257 * Set vPCR for control line interrupts (but not on RBV)
260 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
261 * are made negative edge triggered here.
263 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
264 /* CB2 (IRQ) indep. input, positive edge */
265 /* CA2 (DRQ) indep. input, positive edge */
268 /* CB2 (IRQ) indep. input, negative edge */
269 /* CA2 (DRQ) indep. input, negative edge */
276 * Start the 100 Hz clock
279 void __init via_init_clock(irq_handler_t func)
282 via1[vT1LL] = MAC_CLOCK_LOW;
283 via1[vT1LH] = MAC_CLOCK_HIGH;
284 via1[vT1CL] = MAC_CLOCK_LOW;
285 via1[vT1CH] = MAC_CLOCK_HIGH;
287 if (request_irq(IRQ_MAC_TIMER_1, func, 0, "timer", func))
288 pr_err("Couldn't register %s interrupt\n", "timer");
292 * Register the interrupt dispatchers for VIA or RBV machines only.
295 void __init via_register_interrupts(void)
297 if (via_alt_mapping) {
298 if (request_irq(IRQ_AUTO_1, via1_irq, 0, "software",
300 pr_err("Couldn't register %s interrupt\n", "software");
301 if (request_irq(IRQ_AUTO_6, via1_irq, 0, "via1", (void *)via1))
302 pr_err("Couldn't register %s interrupt\n", "via1");
304 if (request_irq(IRQ_AUTO_1, via1_irq, 0, "via1", (void *)via1))
305 pr_err("Couldn't register %s interrupt\n", "via1");
307 if (request_irq(IRQ_AUTO_2, via2_irq, 0, "via2", (void *)via2))
308 pr_err("Couldn't register %s interrupt\n", "via2");
309 if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq, 0, "nubus",
311 pr_err("Couldn't register %s interrupt\n", "nubus");
315 * Debugging dump, used in various places to see what's going on.
318 void via_debug_dump(void)
320 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
321 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
322 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
323 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
325 printk(KERN_DEBUG "VIA2: <OSS>\n");
326 } else if (rbv_present) {
327 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
328 (uint) via2[rIFR], (uint) via2[rIER]);
329 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
330 (uint) via2[rSIFR], (uint) via2[rSIER]);
332 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
333 (uint) via2[vDirA], (uint) via2[vDirB],
335 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
337 (uint) via2[vIFR], (uint) via2[vIER]);
342 * This is always executed with interrupts disabled.
344 * TBI: get time offset between scheduling timer ticks
347 unsigned long mac_gettimeoffset (void)
349 unsigned long ticks, offset = 0;
351 /* read VIA1 timer 2 current value */
352 ticks = via1[vT1CL] | (via1[vT1CH] << 8);
353 /* The probability of underflow is less than 2% */
354 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
355 /* Check for pending timer interrupt in VIA1 IFR */
356 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
358 ticks = MAC_CLOCK_TICK - ticks;
359 ticks = ticks * 10000L / MAC_CLOCK_TICK;
361 return ticks + offset;
365 * Flush the L2 cache on Macs that have it by flipping
366 * the system into 24-bit mode for an instant.
369 void via_flush_cache(void)
371 via2[gBufB] &= ~VIA2B_vMode32;
372 via2[gBufB] |= VIA2B_vMode32;
376 * Return the status of the L2 cache on a IIci
379 int via_get_cache_disable(void)
381 /* Safeguard against being called accidentally */
383 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
387 return (int) via2[gBufB] & VIA2B_vCDis;
391 * Initialize VIA2 for Nubus access
394 void __init via_nubus_init(void)
396 /* unlock nubus transactions */
398 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
399 (macintosh_config->adb_type != MAC_ADB_PB2)) {
400 /* set the line to be an output on non-RBV machines */
404 /* this seems to be an ADB bit on PMU machines */
405 /* according to MkLinux. -- jmt */
409 /* Disable all the slot interrupts (where possible). */
411 switch (macintosh_config->via_type) {
413 /* Just make the port A lines inputs. */
414 switch(macintosh_config->ident) {
419 /* The top two bits are RAM size outputs. */
427 /* RBV. Disable all the slot interrupts. SIER works like IER. */
431 /* Disable the inactive slot interrupts by making those lines outputs. */
432 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
433 (macintosh_config->adb_type != MAC_ADB_PB2)) {
442 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
443 * via6522.c :-), disable/pending masks added.
446 irqreturn_t via1_irq(int irq, void *dev_id)
449 unsigned char irq_bit, events;
451 events = via1[vIFR] & via1[vIER] & 0x7F;
455 irq_num = VIA1_SOURCE_BASE;
458 if (events & irq_bit) {
459 via1[vIFR] = irq_bit;
460 generic_handle_irq(irq_num);
464 } while (events >= irq_bit);
468 irqreturn_t via2_irq(int irq, void *dev_id)
471 unsigned char irq_bit, events;
473 events = via2[gIFR] & via2[gIER] & 0x7F;
477 irq_num = VIA2_SOURCE_BASE;
480 if (events & irq_bit) {
481 via2[gIFR] = irq_bit | rbv_clear;
482 generic_handle_irq(irq_num);
486 } while (events >= irq_bit);
491 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
492 * VIA2 dispatcher as a fast interrupt handler.
495 irqreturn_t via_nubus_irq(int irq, void *dev_id)
498 unsigned char slot_bit, events;
500 events = ~via2[gBufA] & 0x7F;
502 events &= via2[rSIER];
504 events &= ~via2[vDirA];
509 slot_irq = IRQ_NUBUS_F;
512 if (events & slot_bit) {
514 generic_handle_irq(slot_irq);
520 /* clear the CA1 interrupt and make certain there's no more. */
521 via2[gIFR] = 0x02 | rbv_clear;
522 events = ~via2[gBufA] & 0x7F;
524 events &= via2[rSIER];
526 events &= ~via2[vDirA];
531 void via_irq_enable(int irq) {
532 int irq_src = IRQ_SRC(irq);
533 int irq_idx = IRQ_IDX(irq);
536 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
540 via1[vIER] = IER_SET_BIT(irq_idx);
541 } else if (irq_src == 2) {
542 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
543 via2[gIER] = IER_SET_BIT(irq_idx);
544 } else if (irq_src == 7) {
545 switch (macintosh_config->via_type) {
547 nubus_disabled &= ~(1 << irq_idx);
548 /* Enable the CA1 interrupt when no slot is disabled. */
550 via2[gIER] = IER_SET_BIT(1);
553 /* On RBV, enable the slot interrupt.
554 * SIER works like IER.
556 via2[rSIER] = IER_SET_BIT(irq_idx);
559 /* Make the port A line an input to enable the slot irq.
560 * But not on PowerBooks, that's ADB.
562 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
563 (macintosh_config->adb_type != MAC_ADB_PB2))
564 via2[vDirA] &= ~(1 << irq_idx);
570 void via_irq_disable(int irq) {
571 int irq_src = IRQ_SRC(irq);
572 int irq_idx = IRQ_IDX(irq);
575 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
579 via1[vIER] = IER_CLR_BIT(irq_idx);
580 } else if (irq_src == 2) {
581 via2[gIER] = IER_CLR_BIT(irq_idx);
582 } else if (irq_src == 7) {
583 switch (macintosh_config->via_type) {
585 nubus_disabled |= 1 << irq_idx;
587 via2[gIER] = IER_CLR_BIT(1);
590 via2[rSIER] = IER_CLR_BIT(irq_idx);
593 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
594 (macintosh_config->adb_type != MAC_ADB_PB2))
595 via2[vDirA] |= 1 << irq_idx;
601 void via_irq_clear(int irq) {
602 int irq_src = IRQ_SRC(irq);
603 int irq_idx = IRQ_IDX(irq);
604 int irq_bit = 1 << irq_idx;
607 via1[vIFR] = irq_bit;
608 } else if (irq_src == 2) {
609 via2[gIFR] = irq_bit | rbv_clear;
610 } else if (irq_src == 7) {
611 /* FIXME: There is no way to clear an individual nubus slot
612 * IRQ flag, other than getting the device to do it.
618 * Returns nonzero if an interrupt is pending on the given
619 * VIA/IRQ combination.
622 int via_irq_pending(int irq)
624 int irq_src = IRQ_SRC(irq);
625 int irq_idx = IRQ_IDX(irq);
626 int irq_bit = 1 << irq_idx;
629 return via1[vIFR] & irq_bit;
630 } else if (irq_src == 2) {
631 return via2[gIFR] & irq_bit;
632 } else if (irq_src == 7) {
633 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
634 return ~via2[gBufA] & irq_bit;
639 void via1_set_head(int head)
642 via1[vBufA] &= ~VIA1A_vHeadSel;
644 via1[vBufA] |= VIA1A_vHeadSel;
646 EXPORT_SYMBOL(via1_set_head);