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 /* Some machines support an alternate IRQ mapping that spreads */
198 /* Ethernet and Sound out to their own autolevel IRQs and moves */
199 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
200 /* that the IIfx emulates this alternate mapping using the OSS. */
203 if (macintosh_config->via_type == MAC_VIA_QUADRA)
204 switch (macintosh_config->ident) {
211 case MAC_MODEL_PB140:
212 case MAC_MODEL_PB145:
213 case MAC_MODEL_PB160:
214 case MAC_MODEL_PB165:
215 case MAC_MODEL_PB165C:
216 case MAC_MODEL_PB170:
217 case MAC_MODEL_PB180:
218 case MAC_MODEL_PB180C:
219 case MAC_MODEL_PB190:
220 case MAC_MODEL_PB520:
226 via1[vBufB] &= ~0x40;
231 * Now initialize VIA2. For RBV we just kill all interrupts;
232 * for a regular VIA we also reset the timers and stuff.
236 via2[gIFR] = 0x7F | rbv_clear;
244 via2[vACR] &= ~0xC0; /* setup T1 timer with no PB7 output */
245 via2[vACR] &= ~0x03; /* disable port A & B latches */
249 * Set vPCR for control line interrupts (but not on RBV)
252 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
253 * are made negative edge triggered here.
255 if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
256 /* CB2 (IRQ) indep. input, positive edge */
257 /* CA2 (DRQ) indep. input, positive edge */
260 /* CB2 (IRQ) indep. input, negative edge */
261 /* CA2 (DRQ) indep. input, negative edge */
268 * Start the 100 Hz clock
271 void __init via_init_clock(irq_handler_t func)
274 via1[vT1LL] = MAC_CLOCK_LOW;
275 via1[vT1LH] = MAC_CLOCK_HIGH;
276 via1[vT1CL] = MAC_CLOCK_LOW;
277 via1[vT1CH] = MAC_CLOCK_HIGH;
279 if (request_irq(IRQ_MAC_TIMER_1, func, 0, "timer", func))
280 pr_err("Couldn't register %s interrupt\n", "timer");
284 * Debugging dump, used in various places to see what's going on.
287 void via_debug_dump(void)
289 printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
290 (uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
291 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
292 (uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
294 printk(KERN_DEBUG "VIA2: <OSS>\n");
295 } else if (rbv_present) {
296 printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
297 (uint) via2[rIFR], (uint) via2[rIER]);
298 printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
299 (uint) via2[rSIFR], (uint) via2[rSIER]);
301 printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
302 (uint) via2[vDirA], (uint) via2[vDirB],
304 printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
306 (uint) via2[vIFR], (uint) via2[vIER]);
311 * This is always executed with interrupts disabled.
313 * TBI: get time offset between scheduling timer ticks
316 unsigned long mac_gettimeoffset (void)
318 unsigned long ticks, offset = 0;
320 /* read VIA1 timer 2 current value */
321 ticks = via1[vT1CL] | (via1[vT1CH] << 8);
322 /* The probability of underflow is less than 2% */
323 if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
324 /* Check for pending timer interrupt in VIA1 IFR */
325 if (via1[vIFR] & 0x40) offset = TICK_SIZE;
327 ticks = MAC_CLOCK_TICK - ticks;
328 ticks = ticks * 10000L / MAC_CLOCK_TICK;
330 return ticks + offset;
334 * Flush the L2 cache on Macs that have it by flipping
335 * the system into 24-bit mode for an instant.
338 void via_flush_cache(void)
340 via2[gBufB] &= ~VIA2B_vMode32;
341 via2[gBufB] |= VIA2B_vMode32;
345 * Return the status of the L2 cache on a IIci
348 int via_get_cache_disable(void)
350 /* Safeguard against being called accidentally */
352 printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
356 return (int) via2[gBufB] & VIA2B_vCDis;
360 * Initialize VIA2 for Nubus access
363 void __init via_nubus_init(void)
365 /* unlock nubus transactions */
367 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
368 (macintosh_config->adb_type != MAC_ADB_PB2)) {
369 /* set the line to be an output on non-RBV machines */
373 /* this seems to be an ADB bit on PMU machines */
374 /* according to MkLinux. -- jmt */
378 /* Disable all the slot interrupts (where possible). */
380 switch (macintosh_config->via_type) {
382 /* Just make the port A lines inputs. */
383 switch(macintosh_config->ident) {
388 /* The top two bits are RAM size outputs. */
396 /* RBV. Disable all the slot interrupts. SIER works like IER. */
400 /* Disable the inactive slot interrupts by making those lines outputs. */
401 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
402 (macintosh_config->adb_type != MAC_ADB_PB2)) {
411 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
412 * via6522.c :-), disable/pending masks added.
415 void via1_irq(unsigned int irq, struct irq_desc *desc)
418 unsigned char irq_bit, events;
420 events = via1[vIFR] & via1[vIER] & 0x7F;
424 irq_num = VIA1_SOURCE_BASE;
427 if (events & irq_bit) {
428 via1[vIFR] = irq_bit;
429 generic_handle_irq(irq_num);
433 } while (events >= irq_bit);
436 static void via2_irq(unsigned int irq, struct irq_desc *desc)
439 unsigned char irq_bit, events;
441 events = via2[gIFR] & via2[gIER] & 0x7F;
445 irq_num = VIA2_SOURCE_BASE;
448 if (events & irq_bit) {
449 via2[gIFR] = irq_bit | rbv_clear;
450 generic_handle_irq(irq_num);
454 } while (events >= irq_bit);
458 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
459 * VIA2 dispatcher as a fast interrupt handler.
462 void via_nubus_irq(unsigned int irq, struct irq_desc *desc)
465 unsigned char slot_bit, events;
467 events = ~via2[gBufA] & 0x7F;
469 events &= via2[rSIER];
471 events &= ~via2[vDirA];
476 slot_irq = IRQ_NUBUS_F;
479 if (events & slot_bit) {
481 generic_handle_irq(slot_irq);
487 /* clear the CA1 interrupt and make certain there's no more. */
488 via2[gIFR] = 0x02 | rbv_clear;
489 events = ~via2[gBufA] & 0x7F;
491 events &= via2[rSIER];
493 events &= ~via2[vDirA];
498 * Register the interrupt dispatchers for VIA or RBV machines only.
501 void __init via_register_interrupts(void)
503 if (via_alt_mapping) {
504 /* software interrupt */
505 irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
507 irq_set_chained_handler(IRQ_AUTO_6, via1_irq);
509 irq_set_chained_handler(IRQ_AUTO_1, via1_irq);
511 irq_set_chained_handler(IRQ_AUTO_2, via2_irq);
512 irq_set_chained_handler(IRQ_MAC_NUBUS, via_nubus_irq);
515 void via_irq_enable(int irq) {
516 int irq_src = IRQ_SRC(irq);
517 int irq_idx = IRQ_IDX(irq);
520 printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
524 via1[vIER] = IER_SET_BIT(irq_idx);
525 } else if (irq_src == 2) {
526 if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
527 via2[gIER] = IER_SET_BIT(irq_idx);
528 } else if (irq_src == 7) {
529 switch (macintosh_config->via_type) {
531 nubus_disabled &= ~(1 << irq_idx);
532 /* Enable the CA1 interrupt when no slot is disabled. */
534 via2[gIER] = IER_SET_BIT(1);
537 /* On RBV, enable the slot interrupt.
538 * SIER works like IER.
540 via2[rSIER] = IER_SET_BIT(irq_idx);
543 /* Make the port A line an input to enable the slot irq.
544 * But not on PowerBooks, that's ADB.
546 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
547 (macintosh_config->adb_type != MAC_ADB_PB2))
548 via2[vDirA] &= ~(1 << irq_idx);
554 void via_irq_disable(int irq) {
555 int irq_src = IRQ_SRC(irq);
556 int irq_idx = IRQ_IDX(irq);
559 printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
563 via1[vIER] = IER_CLR_BIT(irq_idx);
564 } else if (irq_src == 2) {
565 via2[gIER] = IER_CLR_BIT(irq_idx);
566 } else if (irq_src == 7) {
567 switch (macintosh_config->via_type) {
569 nubus_disabled |= 1 << irq_idx;
571 via2[gIER] = IER_CLR_BIT(1);
574 via2[rSIER] = IER_CLR_BIT(irq_idx);
577 if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
578 (macintosh_config->adb_type != MAC_ADB_PB2))
579 via2[vDirA] |= 1 << irq_idx;
585 void via1_set_head(int head)
588 via1[vBufA] &= ~VIA1A_vHeadSel;
590 via1[vBufA] |= VIA1A_vHeadSel;
592 EXPORT_SYMBOL(via1_set_head);
594 int via2_scsi_drq_pending(void)
596 return via2[gIFR] & (1 << IRQ_IDX(IRQ_MAC_SCSIDRQ));
598 EXPORT_SYMBOL(via2_scsi_drq_pending);