2 * 6522 Versatile Interface Adapter (VIA)
4 * There are two of these on the Mac II. Some IRQ's 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 * PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
17 * by Erik Vogan and adapted to Linux by Joshua M. Thompson (funaho@jurai.org)
21 #include <linux/types.h>
22 #include <linux/kernel.h>
24 #include <linux/delay.h>
25 #include <linux/init.h>
27 #include <asm/traps.h>
28 #include <asm/bootinfo.h>
29 #include <asm/macintosh.h>
30 #include <asm/macints.h>
31 #include <asm/machw.h>
32 #include <asm/mac_via.h>
33 #include <asm/mac_psc.h>
35 volatile __u8
*via1
, *via2
;
37 /* See note in mac_via.h about how this is possibly not useful */
38 volatile long *via_memory_bogon
=(long *)&via_memory_bogon
;
40 int rbv_present
,via_alt_mapping
;
44 * Globals for accessing the VIA chip registers without having to
45 * check if we're hitting a real VIA or an RBV. Normally you could
46 * just hit the combined register (ie, vIER|rIER) but that seems to
47 * break on AV Macs...probably because they actually decode more than
48 * eight address bits. Why can't Apple engineers at least be
49 * _consistantly_ lazy? - 1999-05-21 (jmt)
52 static int gIER
,gIFR
,gBufA
,gBufB
;
58 #define TICK_SIZE 10000
59 #define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */
60 #define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF)
61 #define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8)
63 static int nubus_active
;
65 void via_debug_dump(void);
66 void via1_irq(int, void *, struct pt_regs
*);
67 void via2_irq(int, void *, struct pt_regs
*);
68 void via_nubus_irq(int, void *, struct pt_regs
*);
69 void via_irq_enable(int irq
);
70 void via_irq_disable(int irq
);
71 void via_irq_clear(int irq
);
73 extern void mac_bang(int, void *, struct pt_regs
*);
74 extern void mac_SCC_handler(int, void *, struct pt_regs
*);
75 extern int console_loglevel
;
76 extern int oss_present
;
81 * First we figure out where they actually _are_ as well as what type of
82 * VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
83 * Then we pretty much clear them out and disable all IRQ sources.
85 * Note: the OSS is actually "detected" here and not in oss_init(). It just
86 * seems more logical to do it here since via_init() needs to know
87 * these things anyways.
90 void __init
via_init(void)
92 switch(macintosh_config
->via_type
) {
94 /* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
97 via1
= (void *) VIA1_BASE
;
98 if (macintosh_config
->ident
== MAC_MODEL_IIFX
) {
103 via2
= (void *) RBV_BASE
;
107 if (macintosh_config
->ident
== MAC_MODEL_LCIII
) {
110 /* on most RBVs (& unlike the VIAs), you */
111 /* need to set bit 7 when you write to IFR */
112 /* in order for your clear to occur. */
121 /* Quadra and early MacIIs agree on the VIA locations */
125 via1
= (void *) VIA1_BASE
;
126 via2
= (void *) VIA2_BASE
;
136 panic("UNKNOWN VIA TYPE");
139 printk("VIA1 at %p is a 6522 or clone\n", via1
);
141 printk("VIA2 at %p is ", via2
);
144 } else if (oss_present
) {
147 printk("a 6522 or clone\n");
155 * Shut down all IRQ sources, reset the timers, and
156 * kill the timer latch on VIA1.
170 * SE/30: disable video IRQ
171 * XXX: testing for SE/30 VBL
174 if (macintosh_config
->ident
== MAC_MODEL_SE30
) {
180 * Set the RTC bits to a known state: all lines to outputs and
181 * RTC disabled (yes that's 0 to enable and 1 to disable).
184 via1
[vDirB
] |= (VIA1B_vRTCEnb
| VIA1B_vRTCClk
| VIA1B_vRTCData
);
185 via1
[vBufB
] |= (VIA1B_vRTCEnb
| VIA1B_vRTCClk
);
187 /* Everything below this point is VIA2/RBV only... */
189 if (oss_present
) return;
192 /* Some machines support an alternate IRQ mapping that spreads */
193 /* Ethernet and Sound out to their own autolevel IRQs and moves */
194 /* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
195 /* that the IIfx emulates this alternate mapping using the OSS. */
197 switch(macintosh_config
->ident
) {
208 via1
[vBufB
] &= ~0x40;
215 /* The alernate IRQ mapping seems to just not work. Anyone with a */
216 /* supported machine is welcome to take a stab at fixing it. It */
217 /* _should_ work on the following Quadras: 610,650,700,800,900,950 */
218 /* - 1999-06-12 (jmt) */
224 * Now initialize VIA2. For RBV we just kill all interrupts;
225 * for a regular VIA we also reset the timers and stuff.
229 via2
[gIFR
] = 0x7F | rbv_clear
;
242 * Start the 100 Hz clock
245 void __init
via_init_clock(void (*func
)(int, void *, struct pt_regs
*))
248 via1
[vT1LL
] = MAC_CLOCK_LOW
;
249 via1
[vT1LH
] = MAC_CLOCK_HIGH
;
250 via1
[vT1CL
] = MAC_CLOCK_LOW
;
251 via1
[vT1CH
] = MAC_CLOCK_HIGH
;
253 request_irq(IRQ_MAC_TIMER_1
, func
, IRQ_FLG_LOCK
, "timer", func
);
257 * Register the interrupt dispatchers for VIA or RBV machines only.
260 void __init
via_register_interrupts(void)
262 if (via_alt_mapping
) {
263 request_irq(IRQ_AUTO_1
, via1_irq
, IRQ_FLG_LOCK
|IRQ_FLG_FAST
,
264 "Software IRQ", (void *) via1
);
265 request_irq(IRQ_AUTO_6
, via1_irq
, IRQ_FLG_LOCK
|IRQ_FLG_FAST
,
266 "VIA1 Dispatch", (void *) via1
);
268 request_irq(IRQ_AUTO_1
, via1_irq
, IRQ_FLG_LOCK
|IRQ_FLG_FAST
,
269 "VIA1 Dispatch", (void *) via1
);
270 #if 0 /* interferes with serial on some machines */
272 request_irq(IRQ_AUTO_6
, mac_bang
, IRQ_FLG_LOCK
,
273 "Off Switch", mac_bang
);
277 request_irq(IRQ_AUTO_2
, via2_irq
, IRQ_FLG_LOCK
|IRQ_FLG_FAST
,
278 "VIA2 Dispatch", (void *) via2
);
280 request_irq(IRQ_AUTO_4
, mac_SCC_handler
, IRQ_FLG_LOCK
,
281 "SCC Dispatch", mac_SCC_handler
);
283 request_irq(IRQ_MAC_NUBUS
, via_nubus_irq
, IRQ_FLG_LOCK
|IRQ_FLG_FAST
,
284 "Nubus Dispatch", (void *) via2
);
288 * Debugging dump, used in various places to see what's going on.
291 void via_debug_dump(void)
293 printk("VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
294 (uint
) via1
[vDirA
], (uint
) via1
[vDirB
], (uint
) via1
[vACR
]);
295 printk(" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
296 (uint
) via1
[vPCR
], (uint
) via1
[vIFR
], (uint
) via1
[vIER
]);
298 printk("VIA2: <OSS>\n");
299 } else if (rbv_present
) {
300 printk("VIA2: IFR = 0x%02X IER = 0x%02X\n",
301 (uint
) via2
[rIFR
], (uint
) via2
[rIER
]);
302 printk(" SIFR = 0x%02X SIER = 0x%02X\n",
303 (uint
) via2
[rSIFR
], (uint
) via2
[rSIER
]);
305 printk("VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
306 (uint
) via2
[vDirA
], (uint
) via2
[vDirB
],
308 printk(" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
310 (uint
) via2
[vIFR
], (uint
) via2
[vIER
]);
315 * This is always executed with interrupts disabled.
317 * TBI: get time offset between scheduling timer ticks
320 unsigned long mac_gettimeoffset (void)
322 unsigned long ticks
, offset
= 0;
324 /* read VIA1 timer 2 current value */
325 ticks
= via1
[vT1CL
] | (via1
[vT1CH
] << 8);
326 /* The probability of underflow is less than 2% */
327 if (ticks
> MAC_CLOCK_TICK
- MAC_CLOCK_TICK
/ 50)
328 /* Check for pending timer interrupt in VIA1 IFR */
329 if (via1
[vIFR
] & 0x40) offset
= TICK_SIZE
;
331 ticks
= MAC_CLOCK_TICK
- ticks
;
332 ticks
= ticks
* 10000L / MAC_CLOCK_TICK
;
334 return ticks
+ offset
;
338 * Flush the L2 cache on Macs that have it by flipping
339 * the system into 24-bit mode for an instant.
342 void via_flush_cache(void)
344 via2
[gBufB
] &= ~VIA2B_vMode32
;
345 via2
[gBufB
] |= VIA2B_vMode32
;
349 * Return the status of the L2 cache on a IIci
352 int via_get_cache_disable(void)
354 /* Safeguard against being called accidentally */
356 printk(KERN_ERR
"via_get_cache_disable called on a non-VIA machine!\n");
360 return (int) via2
[gBufB
] & VIA2B_vCDis
;
364 * VIA-based power switch, for machines that support it.
367 void via_poweroff(void)
370 via2
[rBufB
] &= ~0x04;
372 /* Direction of vDirB is output */
374 /* Send a value of 0 on that line */
375 via2
[vBufB
] &= ~0x04;
376 /* Otherwise it prints "It is now.." then shuts off */
380 /* We should never make it this far... */
381 printk ("It is now safe to switch off your machine.\n");
386 * Initialize VIA2 for Nubus access
389 void __init
via_nubus_init(void)
393 /* unlock nubus transactions */
396 /* set the line to be an output on non-RBV machines */
401 /* disable nubus slot interrupts. */
403 via2
[rSIER
] = 0x7F; /* like VIA; bit 7=clr,set */
405 via2
[vBufA
] = 0xFF; /* active low irqs, force high */
406 via2
[vDirA
] = 0xFF; /* ddr to output. */
411 * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
412 * via6522.c :-), disable/pending masks added.
414 * The new interrupt architecture in macints.c takes care of a lot of the
415 * gruntwork for us, including tallying the interrupts and calling the
416 * handlers on the linked list. All we need to do here is basically generate
417 * the machspec interrupt number after clearing the interrupt.
420 void via1_irq(int irq
, void *dev_id
, struct pt_regs
*regs
)
423 unsigned char events
, mask
;
427 mask
= via1
[vIER
] & 0x7F;
428 if (!(events
= via1
[vIFR
] & mask
)) return;
430 for (i
= 0, irq_bit
= 1 ; i
< 7 ; i
++, irq_bit
<<= 1)
431 if (events
& irq_bit
) {
432 via1
[vIER
] = irq_bit
;
433 mac_do_irq_list(VIA1_SOURCE_BASE
+ i
, regs
);
434 via1
[vIFR
] = irq_bit
;
435 via1
[vIER
] = irq_bit
| 0x80;
439 /* This (still) seems to be necessary to get IDE
440 working. However, if you enable VBL interrupts,
442 /* FIXME: should we check the SLOTIRQ bit before
443 pulling this stunt? */
444 /* No, it won't be set. that's why we're doing this. */
445 via_irq_disable(IRQ_MAC_NUBUS
);
446 via_irq_clear(IRQ_MAC_NUBUS
);
447 mac_do_irq_list(IRQ_MAC_NUBUS
, regs
);
448 via_irq_enable(IRQ_MAC_NUBUS
);
452 void via2_irq(int irq
, void *dev_id
, struct pt_regs
*regs
)
455 unsigned char events
, mask
;
459 mask
= via2
[gIER
] & 0x7F;
460 if (!(events
= via2
[gIFR
] & mask
)) return;
462 for (i
= 0, irq_bit
= 1 ; i
< 7 ; i
++, irq_bit
<<= 1)
463 if (events
& irq_bit
) {
464 via2
[gIER
] = irq_bit
;
465 mac_do_irq_list(VIA2_SOURCE_BASE
+ i
, regs
);
466 via2
[gIFR
] = irq_bit
| rbv_clear
;
467 via2
[gIER
] = irq_bit
| 0x80;
472 * Dispatch Nubus interrupts. We are called as a secondary dispatch by the
473 * VIA2 dispatcher as a fast interrupt handler.
476 void via_nubus_irq(int irq
, void *dev_id
, struct pt_regs
*regs
)
479 unsigned char events
;
481 if (!(events
= ~via2
[gBufA
] & nubus_active
)) return;
483 for (i
= 0, irq_bit
= 1 ; i
< 7 ; i
++, irq_bit
<<= 1) {
484 if (events
& irq_bit
) {
485 via_irq_disable(NUBUS_SOURCE_BASE
+ i
);
486 mac_do_irq_list(NUBUS_SOURCE_BASE
+ i
, regs
);
487 via_irq_enable(NUBUS_SOURCE_BASE
+ i
);
492 void via_irq_enable(int irq
) {
493 int irq_src
= IRQ_SRC(irq
);
494 int irq_idx
= IRQ_IDX(irq
);
495 int irq_bit
= 1 << irq_idx
;
498 printk("via_irq_enable(%d)\n", irq
);
502 via1
[vIER
] = irq_bit
| 0x80;
503 } else if (irq_src
== 2) {
505 * Set vPCR for SCSI interrupts (but not on RBV)
507 if ((irq_idx
== 0) && !rbv_present
) {
508 if (macintosh_config
->scsi_type
== MAC_SCSI_OLD
) {
509 /* CB2 (IRQ) indep. input, positive edge */
510 /* CA2 (DRQ) indep. input, positive edge */
513 /* CB2 (IRQ) indep. input, negative edge */
514 /* CA2 (DRQ) indep. input, negative edge */
518 via2
[gIER
] = irq_bit
| 0x80;
519 } else if (irq_src
== 7) {
521 /* enable the slot interrupt. SIER works like IER. */
522 via2
[rSIER
] = IER_SET_BIT(irq_idx
);
524 /* Make sure the bit is an input, to enable the irq */
525 via2
[vDirA
] &= ~irq_bit
;
527 nubus_active
|= irq_bit
;
531 void via_irq_disable(int irq
) {
532 int irq_src
= IRQ_SRC(irq
);
533 int irq_idx
= IRQ_IDX(irq
);
534 int irq_bit
= 1 << irq_idx
;
537 printk("via_irq_disable(%d)\n", irq
);
541 via1
[vIER
] = irq_bit
;
542 } else if (irq_src
== 2) {
543 via2
[gIER
] = irq_bit
;
544 } else if (irq_src
== 7) {
546 /* disable the slot interrupt. SIER works like IER. */
547 via2
[rSIER
] = IER_CLR_BIT(irq_idx
);
549 /* disable the nubus irq by changing dir to output */
550 via2
[vDirA
] |= irq_bit
;
552 nubus_active
&= ~irq_bit
;
556 void via_irq_clear(int irq
) {
557 int irq_src
= IRQ_SRC(irq
);
558 int irq_idx
= IRQ_IDX(irq
);
559 int irq_bit
= 1 << irq_idx
;
562 via1
[vIFR
] = irq_bit
;
563 } else if (irq_src
== 2) {
564 via2
[gIFR
] = irq_bit
| rbv_clear
;
565 } else if (irq_src
== 7) {
571 * Returns nonzero if an interrupt is pending on the given
572 * VIA/IRQ combination.
575 int via_irq_pending(int irq
)
577 int irq_src
= IRQ_SRC(irq
);
578 int irq_idx
= IRQ_IDX(irq
);
579 int irq_bit
= 1 << irq_idx
;
582 return via1
[vIFR
] & irq_bit
;
583 } else if (irq_src
== 2) {
584 return via2
[gIFR
] & irq_bit
;
585 } else if (irq_src
== 7) {
586 return ~via2
[gBufA
] & irq_bit
;
591 void via_scsi_clear(void)
593 volatile unsigned char deep_magic
;
596 printk("via_scsi_clear()\n");
599 /* We handle this in oss.c , but this gets called in mac_scsinew.c */
600 if(oss_present
) return;
603 via2
[rIFR
] = (1<<3) | (1<<0) | rbv_clear
;
604 deep_magic
= via2
[rBufB
];
606 deep_magic
= via2
[vBufB
];
608 mac_enable_irq(IRQ_MAC_SCSI
);
612 * PRAM/RTC access routines
614 * Must be called with interrupts disabled and
615 * the RTC should be enabled.
618 static __u8
via_pram_readbyte(void)
623 reg
= via1
[vBufB
] & ~VIA1B_vRTCClk
;
625 /* Set the RTC data line to be an input. */
627 via1
[vDirB
] &= ~VIA1B_vRTCData
;
629 /* The bits of the byte come out in MSB order */
632 for (i
= 0 ; i
< 8 ; i
++) {
634 via1
[vBufB
] = reg
| VIA1B_vRTCClk
;
635 data
= (data
<< 1) | (via1
[vBufB
] & VIA1B_vRTCData
);
638 /* Return RTC data line to output state */
640 via1
[vDirB
] |= VIA1B_vRTCData
;
645 static void via_pram_writebyte(__u8 data
)
649 reg
= via1
[vBufB
] & ~(VIA1B_vRTCClk
| VIA1B_vRTCData
);
651 /* The bits of the byte go in in MSB order */
653 for (i
= 0 ; i
< 8 ; i
++) {
654 bit
= data
& 0x80? 1 : 0;
656 via1
[vBufB
] = reg
| bit
;
657 via1
[vBufB
] = reg
| bit
| VIA1B_vRTCClk
;
662 * Execute a PRAM/RTC command. For read commands
663 * data should point to a one-byte buffer for the
664 * resulting data. For write commands it should point
665 * to the data byte to for the command.
667 * This function disables all interrupts while running.
670 void via_pram_command(int command
, __u8
*data
)
672 unsigned long cpu_flags
;
675 save_flags(cpu_flags
);
678 /* Enable the RTC and make sure the strobe line is high */
680 via1
[vBufB
] = (via1
[vBufB
] | VIA1B_vRTCClk
) & ~VIA1B_vRTCEnb
;
682 if (command
& 0xFF00) { /* extended (two-byte) command */
683 via_pram_writebyte((command
& 0xFF00) >> 8);
684 via_pram_writebyte(command
& 0xFF);
685 is_read
= command
& 0x8000;
686 } else { /* one-byte command */
687 via_pram_writebyte(command
);
688 is_read
= command
& 0x80;
691 *data
= via_pram_readbyte();
693 via_pram_writebyte(*data
);
696 /* All done, disable the RTC */
698 via1
[vBufB
] |= VIA1B_vRTCEnb
;
700 restore_flags(cpu_flags
);
704 * Return the current time in seconds since January 1, 1904.
706 * This only works on machines with the VIA-based PRAM/RTC, which
707 * is basically any machine with Mac II-style ADB.
710 __u32
via_read_time(void)
715 } result
, last_result
;
719 * The NetBSD guys say to loop until you get the same reading
726 printk("via_read_time: couldn't get valid time, "
727 "last read = 0x%08X and 0x%08X\n", last_result
.idata
,
732 last_result
.idata
= result
.idata
;
735 via_pram_command(0x81, &result
.cdata
[3]);
736 via_pram_command(0x85, &result
.cdata
[2]);
737 via_pram_command(0x89, &result
.cdata
[1]);
738 via_pram_command(0x8D, &result
.cdata
[0]);
739 } while (result
.idata
!= last_result
.idata
);
745 * Set the current time to a number of seconds since January 1, 1904.
747 * This only works on machines with the VIA-based PRAM/RTC, which
748 * is basically any machine with Mac II-style ADB.
751 void via_write_time(__u32 time
)
759 /* Clear the write protect bit */
762 via_pram_command(0x35, &temp
);
765 via_pram_command(0x01, &data
.cdata
[3]);
766 via_pram_command(0x05, &data
.cdata
[2]);
767 via_pram_command(0x09, &data
.cdata
[1]);
768 via_pram_command(0x0D, &data
.cdata
[0]);
770 /* Set the write protect bit */
773 via_pram_command(0x35, &temp
);