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);
81 void via_irq_enable(int irq
);
82 void via_irq_disable(int irq
);
83 void via_irq_clear(int irq
);
88 * First we figure out where they actually _are_ as well as what type of
89 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
90 * Then we pretty much clear them out and disable all IRQ sources.
92 * Note: the OSS is actually "detected" here and not in oss_init(). It just
93 * seems more logical to do it here since via_init() needs to know
94 * these things anyways.
97 void __init
via_init(void)
99 switch(macintosh_config
->via_type
) {
101 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
104 via1
= (void *) VIA1_BASE
;
105 if (macintosh_config
->ident
== MAC_MODEL_IIFX
) {
110 via2
= (void *) RBV_BASE
;
114 if (macintosh_config
->ident
== MAC_MODEL_LCIII
) {
117 /* on most RBVs (& unlike the VIAs), you */
118 /* need to set bit 7 when you write to IFR */
119 /* in order for your clear to occur. */
128 /* Quadra and early MacIIs agree on the VIA locations */
132 via1
= (void *) VIA1_BASE
;
133 via2
= (void *) VIA2_BASE
;
143 panic("UNKNOWN VIA TYPE");
146 printk(KERN_INFO
"VIA1 at %p is a 6522 or clone\n", via1
);
148 printk(KERN_INFO
"VIA2 at %p is ", via2
);
151 } else if (oss_present
) {
154 printk("a 6522 or clone\n");
162 * Shut down all IRQ sources, reset the timers, and
163 * kill the timer latch on VIA1.
174 via1
[vACR
] &= ~0xC0; /* setup T1 timer with no PB7 output */
175 via1
[vACR
] &= ~0x03; /* disable port A & B latches */
178 * SE/30: disable video IRQ
179 * XXX: testing for SE/30 VBL
182 if (macintosh_config
->ident
== MAC_MODEL_SE30
) {
188 * Set the RTC bits to a known state: all lines to outputs and
189 * RTC disabled (yes that's 0 to enable and 1 to disable).
192 via1
[vDirB
] |= (VIA1B_vRTCEnb
| VIA1B_vRTCClk
| VIA1B_vRTCData
);
193 via1
[vBufB
] |= (VIA1B_vRTCEnb
| VIA1B_vRTCClk
);
195 /* Everything below this point is VIA2/RBV only... */
200 /* Some machines support an alternate IRQ mapping that spreads */
201 /* Ethernet and Sound out to their own autolevel IRQs and moves */
202 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
203 /* that the IIfx emulates this alternate mapping using the OSS. */
206 if (macintosh_config
->via_type
== MAC_VIA_QUADRA
)
207 switch (macintosh_config
->ident
) {
214 case MAC_MODEL_PB140
:
215 case MAC_MODEL_PB145
:
216 case MAC_MODEL_PB160
:
217 case MAC_MODEL_PB165
:
218 case MAC_MODEL_PB165C
:
219 case MAC_MODEL_PB170
:
220 case MAC_MODEL_PB180
:
221 case MAC_MODEL_PB180C
:
222 case MAC_MODEL_PB190
:
223 case MAC_MODEL_PB520
:
229 via1
[vBufB
] &= ~0x40;
234 * Now initialize VIA2. For RBV we just kill all interrupts;
235 * for a regular VIA we also reset the timers and stuff.
239 via2
[gIFR
] = 0x7F | rbv_clear
;
247 via2
[vACR
] &= ~0xC0; /* setup T1 timer with no PB7 output */
248 via2
[vACR
] &= ~0x03; /* disable port A & B latches */
252 * Set vPCR for control line interrupts (but not on RBV)
255 /* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
256 * are made negative edge triggered here.
258 if (macintosh_config
->scsi_type
== MAC_SCSI_OLD
) {
259 /* CB2 (IRQ) indep. input, positive edge */
260 /* CA2 (DRQ) indep. input, positive edge */
263 /* CB2 (IRQ) indep. input, negative edge */
264 /* CA2 (DRQ) indep. input, negative edge */
271 * Start the 100 Hz clock
274 void __init
via_init_clock(irq_handler_t func
)
277 via1
[vT1LL
] = MAC_CLOCK_LOW
;
278 via1
[vT1LH
] = MAC_CLOCK_HIGH
;
279 via1
[vT1CL
] = MAC_CLOCK_LOW
;
280 via1
[vT1CH
] = MAC_CLOCK_HIGH
;
282 if (request_irq(IRQ_MAC_TIMER_1
, func
, 0, "timer", func
))
283 pr_err("Couldn't register %s interrupt\n", "timer");
287 * Debugging dump, used in various places to see what's going on.
290 void via_debug_dump(void)
292 printk(KERN_DEBUG
"VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
293 (uint
) via1
[vDirA
], (uint
) via1
[vDirB
], (uint
) via1
[vACR
]);
294 printk(KERN_DEBUG
" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
295 (uint
) via1
[vPCR
], (uint
) via1
[vIFR
], (uint
) via1
[vIER
]);
297 printk(KERN_DEBUG
"VIA2: <OSS>\n");
298 } else if (rbv_present
) {
299 printk(KERN_DEBUG
"VIA2: IFR = 0x%02X IER = 0x%02X\n",
300 (uint
) via2
[rIFR
], (uint
) via2
[rIER
]);
301 printk(KERN_DEBUG
" SIFR = 0x%02X SIER = 0x%02X\n",
302 (uint
) via2
[rSIFR
], (uint
) via2
[rSIER
]);
304 printk(KERN_DEBUG
"VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
305 (uint
) via2
[vDirA
], (uint
) via2
[vDirB
],
307 printk(KERN_DEBUG
" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
309 (uint
) via2
[vIFR
], (uint
) via2
[vIER
]);
314 * This is always executed with interrupts disabled.
316 * TBI: get time offset between scheduling timer ticks
319 unsigned long mac_gettimeoffset (void)
321 unsigned long ticks
, offset
= 0;
323 /* read VIA1 timer 2 current value */
324 ticks
= via1
[vT1CL
] | (via1
[vT1CH
] << 8);
325 /* The probability of underflow is less than 2% */
326 if (ticks
> MAC_CLOCK_TICK
- MAC_CLOCK_TICK
/ 50)
327 /* Check for pending timer interrupt in VIA1 IFR */
328 if (via1
[vIFR
] & 0x40) offset
= TICK_SIZE
;
330 ticks
= MAC_CLOCK_TICK
- ticks
;
331 ticks
= ticks
* 10000L / MAC_CLOCK_TICK
;
333 return ticks
+ offset
;
337 * Flush the L2 cache on Macs that have it by flipping
338 * the system into 24-bit mode for an instant.
341 void via_flush_cache(void)
343 via2
[gBufB
] &= ~VIA2B_vMode32
;
344 via2
[gBufB
] |= VIA2B_vMode32
;
348 * Return the status of the L2 cache on a IIci
351 int via_get_cache_disable(void)
353 /* Safeguard against being called accidentally */
355 printk(KERN_ERR
"via_get_cache_disable called on a non-VIA machine!\n");
359 return (int) via2
[gBufB
] & VIA2B_vCDis
;
363 * Initialize VIA2 for Nubus access
366 void __init
via_nubus_init(void)
368 /* unlock nubus transactions */
370 if ((macintosh_config
->adb_type
!= MAC_ADB_PB1
) &&
371 (macintosh_config
->adb_type
!= MAC_ADB_PB2
)) {
372 /* set the line to be an output on non-RBV machines */
376 /* this seems to be an ADB bit on PMU machines */
377 /* according to MkLinux. -- jmt */
381 /* Disable all the slot interrupts (where possible). */
383 switch (macintosh_config
->via_type
) {
385 /* Just make the port A lines inputs. */
386 switch(macintosh_config
->ident
) {
391 /* The top two bits are RAM size outputs. */
399 /* RBV. Disable all the slot interrupts. SIER works like IER. */
403 /* Disable the inactive slot interrupts by making those lines outputs. */
404 if ((macintosh_config
->adb_type
!= MAC_ADB_PB1
) &&
405 (macintosh_config
->adb_type
!= MAC_ADB_PB2
)) {
414 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
415 * via6522.c :-), disable/pending masks added.
418 void via1_irq(unsigned int irq
, struct irq_desc
*desc
)
421 unsigned char irq_bit
, events
;
423 events
= via1
[vIFR
] & via1
[vIER
] & 0x7F;
427 irq_num
= VIA1_SOURCE_BASE
;
430 if (events
& irq_bit
) {
431 via1
[vIFR
] = irq_bit
;
432 generic_handle_irq(irq_num
);
436 } while (events
>= irq_bit
);
439 static void via2_irq(unsigned int irq
, struct irq_desc
*desc
)
442 unsigned char irq_bit
, events
;
444 events
= via2
[gIFR
] & via2
[gIER
] & 0x7F;
448 irq_num
= VIA2_SOURCE_BASE
;
451 if (events
& irq_bit
) {
452 via2
[gIFR
] = irq_bit
| rbv_clear
;
453 generic_handle_irq(irq_num
);
457 } while (events
>= irq_bit
);
461 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
462 * VIA2 dispatcher as a fast interrupt handler.
465 void via_nubus_irq(unsigned int irq
, struct irq_desc
*desc
)
468 unsigned char slot_bit
, events
;
470 events
= ~via2
[gBufA
] & 0x7F;
472 events
&= via2
[rSIER
];
474 events
&= ~via2
[vDirA
];
479 slot_irq
= IRQ_NUBUS_F
;
482 if (events
& slot_bit
) {
484 generic_handle_irq(slot_irq
);
490 /* clear the CA1 interrupt and make certain there's no more. */
491 via2
[gIFR
] = 0x02 | rbv_clear
;
492 events
= ~via2
[gBufA
] & 0x7F;
494 events
&= via2
[rSIER
];
496 events
&= ~via2
[vDirA
];
501 * Register the interrupt dispatchers for VIA or RBV machines only.
504 void __init
via_register_interrupts(void)
506 if (via_alt_mapping
) {
507 /* software interrupt */
508 irq_set_chained_handler(IRQ_AUTO_1
, via1_irq
);
510 irq_set_chained_handler(IRQ_AUTO_6
, via1_irq
);
512 irq_set_chained_handler(IRQ_AUTO_1
, via1_irq
);
514 irq_set_chained_handler(IRQ_AUTO_2
, via2_irq
);
515 irq_set_chained_handler(IRQ_MAC_NUBUS
, via_nubus_irq
);
518 void via_irq_enable(int irq
) {
519 int irq_src
= IRQ_SRC(irq
);
520 int irq_idx
= IRQ_IDX(irq
);
523 printk(KERN_DEBUG
"via_irq_enable(%d)\n", irq
);
527 via1
[vIER
] = IER_SET_BIT(irq_idx
);
528 } else if (irq_src
== 2) {
529 if (irq
!= IRQ_MAC_NUBUS
|| nubus_disabled
== 0)
530 via2
[gIER
] = IER_SET_BIT(irq_idx
);
531 } else if (irq_src
== 7) {
532 switch (macintosh_config
->via_type
) {
534 nubus_disabled
&= ~(1 << irq_idx
);
535 /* Enable the CA1 interrupt when no slot is disabled. */
537 via2
[gIER
] = IER_SET_BIT(1);
540 /* On RBV, enable the slot interrupt.
541 * SIER works like IER.
543 via2
[rSIER
] = IER_SET_BIT(irq_idx
);
546 /* Make the port A line an input to enable the slot irq.
547 * But not on PowerBooks, that's ADB.
549 if ((macintosh_config
->adb_type
!= MAC_ADB_PB1
) &&
550 (macintosh_config
->adb_type
!= MAC_ADB_PB2
))
551 via2
[vDirA
] &= ~(1 << irq_idx
);
557 void via_irq_disable(int irq
) {
558 int irq_src
= IRQ_SRC(irq
);
559 int irq_idx
= IRQ_IDX(irq
);
562 printk(KERN_DEBUG
"via_irq_disable(%d)\n", irq
);
566 via1
[vIER
] = IER_CLR_BIT(irq_idx
);
567 } else if (irq_src
== 2) {
568 via2
[gIER
] = IER_CLR_BIT(irq_idx
);
569 } else if (irq_src
== 7) {
570 switch (macintosh_config
->via_type
) {
572 nubus_disabled
|= 1 << irq_idx
;
574 via2
[gIER
] = IER_CLR_BIT(1);
577 via2
[rSIER
] = IER_CLR_BIT(irq_idx
);
580 if ((macintosh_config
->adb_type
!= MAC_ADB_PB1
) &&
581 (macintosh_config
->adb_type
!= MAC_ADB_PB2
))
582 via2
[vDirA
] |= 1 << irq_idx
;
588 void via_irq_clear(int irq
) {
589 int irq_src
= IRQ_SRC(irq
);
590 int irq_idx
= IRQ_IDX(irq
);
591 int irq_bit
= 1 << irq_idx
;
594 via1
[vIFR
] = irq_bit
;
595 } else if (irq_src
== 2) {
596 via2
[gIFR
] = irq_bit
| rbv_clear
;
597 } else if (irq_src
== 7) {
598 /* FIXME: There is no way to clear an individual nubus slot
599 * IRQ flag, other than getting the device to do it.
605 * Returns nonzero if an interrupt is pending on the given
606 * VIA/IRQ combination.
609 int via_irq_pending(int irq
)
611 int irq_src
= IRQ_SRC(irq
);
612 int irq_idx
= IRQ_IDX(irq
);
613 int irq_bit
= 1 << irq_idx
;
616 return via1
[vIFR
] & irq_bit
;
617 } else if (irq_src
== 2) {
618 return via2
[gIFR
] & irq_bit
;
619 } else if (irq_src
== 7) {
620 /* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
621 return ~via2
[gBufA
] & irq_bit
;
626 void via1_set_head(int head
)
629 via1
[vBufA
] &= ~VIA1A_vHeadSel
;
631 via1
[vBufA
] |= VIA1A_vHeadSel
;
633 EXPORT_SYMBOL(via1_set_head
);