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/*
* 6522 Versatile Interface Adapter (VIA)
*
* There are two of these on the Mac II. Some IRQ's are vectored
* via them as are assorted bits and bobs - eg RTC, ADB.
*
* CSA: Motorola seems to have removed documentation on the 6522 from
* their web site; try
* http://nerini.drf.com/vectrex/other/text/chips/6522/
* http://www.zymurgy.net/classic/vic20/vicdet1.htm
* and
* http://193.23.168.87/mikro_laborversuche/via_iobaustein/via6522_1.html
* for info. A full-text web search on 6522 AND VIA will probably also
* net some usefulness. <cananian@alumni.princeton.edu> 20apr1999
*
* PRAM/RTC access algorithms are from the NetBSD RTC toolkit version 1.08b
* by Erik Vogan and adapted to Linux by Joshua M. Thompson (funaho@jurai.org)
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ide.h>
#include <asm/traps.h>
#include <asm/bootinfo.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/machw.h>
#include <asm/mac_via.h>
#include <asm/mac_psc.h>
volatile __u8 *via1, *via2;
#if 0
/* See note in mac_via.h about how this is possibly not useful */
volatile long *via_memory_bogon=(long *)&via_memory_bogon;
#endif
int rbv_present,via_alt_mapping;
__u8 rbv_clear;
/*
* Globals for accessing the VIA chip registers without having to
* check if we're hitting a real VIA or an RBV. Normally you could
* just hit the combined register (ie, vIER|rIER) but that seems to
* break on AV Macs...probably because they actually decode more than
* eight address bits. Why can't Apple engineers at least be
* _consistantly_ lazy? - 1999-05-21 (jmt)
*/
static int gIER,gIFR,gBufA,gBufB;
/*
* Timer defs.
*/
#define TICK_SIZE 10000
#define MAC_CLOCK_TICK (783300/HZ) /* ticks per HZ */
#define MAC_CLOCK_LOW (MAC_CLOCK_TICK&0xFF)
#define MAC_CLOCK_HIGH (MAC_CLOCK_TICK>>8)
static int nubus_active = 0;
void via_debug_dump(void);
void via1_irq(int, void *, struct pt_regs *);
void via2_irq(int, void *, struct pt_regs *);
void via_nubus_irq(int, void *, struct pt_regs *);
void via_irq_enable(int irq);
void via_irq_disable(int irq);
void via_irq_clear(int irq);
extern void mac_bang(int, void *, struct pt_regs *);
extern void mac_scc_dispatch(int, void *, struct pt_regs *);
extern int oss_present;
/*
* Initialize the VIAs
*
* First we figure out where they actually _are_ as well as what type of
* VIA we have for VIA2 (it could be a real VIA or an RBV or even an OSS.)
* Then we pretty much clear them out and disable all IRQ sources.
*
* Note: the OSS is actually "detected" here and not in oss_init(). It just
* seems more logical to do it here since via_init() needs to know
* these things anyways.
*/
void __init via_init(void)
{
switch(macintosh_config->via_type) {
/* IIci, IIsi, IIvx, IIvi (P6xx), LC series */
case MAC_VIA_IIci:
via1 = (void *) VIA1_BASE;
if (macintosh_config->ident == MAC_MODEL_IIFX) {
via2 = NULL;
rbv_present = 0;
oss_present = 1;
} else {
via2 = (void *) RBV_BASE;
rbv_present = 1;
oss_present = 0;
}
if (macintosh_config->ident == MAC_MODEL_LCIII) {
rbv_clear = 0x00;
} else {
/* on most RBVs (& unlike the VIAs), you */
/* need to set bit 7 when you write to IFR */
/* in order for your clear to occur. */
rbv_clear = 0x80;
}
gIER = rIER;
gIFR = rIFR;
gBufA = rSIFR;
gBufB = rBufB;
break;
/* Quadra and early MacIIs agree on the VIA locations */
case MAC_VIA_QUADRA:
case MAC_VIA_II:
via1 = (void *) VIA1_BASE;
via2 = (void *) VIA2_BASE;
rbv_present = 0;
oss_present = 0;
rbv_clear = 0x00;
gIER = vIER;
gIFR = vIFR;
gBufA = vBufA;
gBufB = vBufB;
break;
default:
panic("UNKNOWN VIA TYPE");
}
printk("VIA1 at %p is a 6522 or clone\n", via1);
printk("VIA2 at %p is ", via2);
if (rbv_present) {
printk("an RBV\n");
} else if (oss_present) {
printk("an OSS\n");
} else {
printk("a 6522 or clone\n");
}
#ifdef DEBUG_VIA
via_debug_dump();
#endif
/*
* Shut down all IRQ sources, reset the timers, and
* kill the timer latch on VIA1.
*/
via1[vIER] = 0x7F;
via1[vIFR] = 0x7F;
via1[vT1LL] = 0;
via1[vT1LH] = 0;
via1[vT1CL] = 0;
via1[vT1CH] = 0;
via1[vT2CL] = 0;
via1[vT2CH] = 0;
via1[vACR] &= 0x3F;
/*
* SE/30: disable video IRQ
* XXX: testing for SE/30 VBL
*/
if (macintosh_config->ident == MAC_MODEL_SE30) {
via1[vDirB] |= 0x40;
via1[vBufB] |= 0x40;
}
/*
* Set the RTC bits to a known state: all lines to outputs and
* RTC disabled (yes that's 0 to enable and 1 to disable).
*/
via1[vDirB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk | VIA1B_vRTCData);
via1[vBufB] |= (VIA1B_vRTCEnb | VIA1B_vRTCClk);
/* Everything below this point is VIA2/RBV only... */
if (oss_present) return;
#if 1
/* Some machines support an alternate IRQ mapping that spreads */
/* Ethernet and Sound out to their own autolevel IRQs and moves */
/* VIA1 to level 6. A/UX uses this mapping and we do too. Note */
/* that the IIfx emulates this alternate mapping using the OSS. */
switch(macintosh_config->ident) {
case MAC_MODEL_C610:
case MAC_MODEL_Q610:
case MAC_MODEL_C650:
case MAC_MODEL_Q650:
case MAC_MODEL_Q700:
case MAC_MODEL_Q800:
case MAC_MODEL_Q900:
case MAC_MODEL_Q950:
via_alt_mapping = 1;
via1[vDirB] |= 0x40;
via1[vBufB] &= ~0x40;
break;
default:
via_alt_mapping = 0;
break;
}
#else
/* The alernate IRQ mapping seems to just not work. Anyone with a */
/* supported machine is welcome to take a stab at fixing it. It */
/* _should_ work on the following Quadras: 610,650,700,800,900,950 */
/* - 1999-06-12 (jmt) */
via_alt_mapping = 0;
#endif
/*
* Now initialize VIA2. For RBV we just kill all interrupts;
* for a regular VIA we also reset the timers and stuff.
*/
via2[gIER] = 0x7F;
via2[gIFR] = 0x7F | rbv_clear;
if (!rbv_present) {
via2[vT1LL] = 0;
via2[vT1LH] = 0;
via2[vT1CL] = 0;
via2[vT1CH] = 0;
via2[vT2CL] = 0;
via2[vT2CH] = 0;
via2[vACR] &= 0x3F;
}
}
/*
* Start the 100 Hz clock
*/
void __init via_init_clock(void (*func)(int, void *, struct pt_regs *))
{
via1[vACR] |= 0x40;
via1[vT1LL] = MAC_CLOCK_LOW;
via1[vT1LH] = MAC_CLOCK_HIGH;
via1[vT1CL] = MAC_CLOCK_LOW;
via1[vT1CH] = MAC_CLOCK_HIGH;
request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func);
}
/*
* Register the interrupt dispatchers for VIA or RBV machines only.
*/
void __init via_register_interrupts(void)
{
if (via_alt_mapping) {
sys_request_irq(IRQ_AUTO_1, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
"software", (void *) via1);
sys_request_irq(IRQ_AUTO_6, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
"via1", (void *) via1);
} else {
sys_request_irq(IRQ_AUTO_1, via1_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
"via1", (void *) via1);
#if 0 /* interferes with serial on some machines */
if (!psc_present) {
sys_request_irq(IRQ_AUTO_6, mac_bang, IRQ_FLG_LOCK,
"Off Switch", mac_bang);
}
#endif
}
sys_request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
"via2", (void *) via2);
if (!psc_present) {
sys_request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
"scc", mac_scc_dispatch);
}
request_irq(IRQ_MAC_NUBUS, via_nubus_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
"nubus", (void *) via2);
}
/*
* Debugging dump, used in various places to see what's going on.
*/
void via_debug_dump(void)
{
printk("VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
printk(" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
if (oss_present) {
printk("VIA2: <OSS>\n");
} else if (rbv_present) {
printk("VIA2: IFR = 0x%02X IER = 0x%02X\n",
(uint) via2[rIFR], (uint) via2[rIER]);
printk(" SIFR = 0x%02X SIER = 0x%02X\n",
(uint) via2[rSIFR], (uint) via2[rSIER]);
} else {
printk("VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
(uint) via2[vDirA], (uint) via2[vDirB],
(uint) via2[vACR]);
printk(" PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
(uint) via2[vPCR],
(uint) via2[vIFR], (uint) via2[vIER]);
}
}
/*
* This is always executed with interrupts disabled.
*
* TBI: get time offset between scheduling timer ticks
*/
unsigned long mac_gettimeoffset (void)
{
unsigned long ticks, offset = 0;
/* read VIA1 timer 2 current value */
ticks = via1[vT1CL] | (via1[vT1CH] << 8);
/* The probability of underflow is less than 2% */
if (ticks > MAC_CLOCK_TICK - MAC_CLOCK_TICK / 50)
/* Check for pending timer interrupt in VIA1 IFR */
if (via1[vIFR] & 0x40) offset = TICK_SIZE;
ticks = MAC_CLOCK_TICK - ticks;
ticks = ticks * 10000L / MAC_CLOCK_TICK;
return ticks + offset;
}
/*
* Flush the L2 cache on Macs that have it by flipping
* the system into 24-bit mode for an instant.
*/
void via_flush_cache(void)
{
via2[gBufB] &= ~VIA2B_vMode32;
via2[gBufB] |= VIA2B_vMode32;
}
/*
* Return the status of the L2 cache on a IIci
*/
int via_get_cache_disable(void)
{
/* Safeguard against being called accidentally */
if (!via2) {
printk(KERN_ERR "via_get_cache_disable called on a non-VIA machine!\n");
return 1;
}
return (int) via2[gBufB] & VIA2B_vCDis;
}
/*
* Initialize VIA2 for Nubus access
*/
void __init via_nubus_init(void)
{
/* don't set nubus_active = 0 here, it kills the Baboon */
/* interrupt that we've already registered. */
/* unlock nubus transactions */
if (!rbv_present) {
/* set the line to be an output on non-RBV machines */
via2[vDirB] |= 0x02;
}
/* this seems to be an ADB bit on PMU machines */
/* according to MkLinux. -- jmt */
if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
(macintosh_config->adb_type != MAC_ADB_PB2)) {
via2[gBufB] |= 0x02;
}
/* disable nubus slot interrupts. */
if (rbv_present) {
via2[rSIER] = 0x7F;
via2[rSIER] = nubus_active | 0x80;
} else {
via2[vBufA] = 0xFF;
via2[vDirA] = ~nubus_active;
}
}
/*
* The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
* via6522.c :-), disable/pending masks added.
*
* The new interrupt architecture in macints.c takes care of a lot of the
* gruntwork for us, including tallying the interrupts and calling the
* handlers on the linked list. All we need to do here is basically generate
* the machspec interrupt number after clearing the interrupt.
*/
void via1_irq(int irq, void *dev_id, struct pt_regs *regs)
{
int irq_bit, i;
unsigned char events, mask;
mask = via1[vIER] & 0x7F;
if (!(events = via1[vIFR] & mask)) return;
for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
if (events & irq_bit) {
via1[vIER] = irq_bit;
mac_do_irq_list(VIA1_SOURCE_BASE + i, regs);
via1[vIFR] = irq_bit;
via1[vIER] = irq_bit | 0x80;
}
#if 0 /* freakin' pmu is doing weird stuff */
if (!oss_present) {
/* This (still) seems to be necessary to get IDE
working. However, if you enable VBL interrupts,
you're screwed... */
/* FIXME: should we check the SLOTIRQ bit before
pulling this stunt? */
/* No, it won't be set. that's why we're doing this. */
via_irq_disable(IRQ_MAC_NUBUS);
via_irq_clear(IRQ_MAC_NUBUS);
mac_do_irq_list(IRQ_MAC_NUBUS, regs);
via_irq_enable(IRQ_MAC_NUBUS);
}
#endif
}
void via2_irq(int irq, void *dev_id, struct pt_regs *regs)
{
int irq_bit, i;
unsigned char events, mask;
mask = via2[gIER] & 0x7F;
if (!(events = via2[gIFR] & mask)) return;
for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1)
if (events & irq_bit) {
via2[gIER] = irq_bit;
mac_do_irq_list(VIA2_SOURCE_BASE + i, regs);
via2[gIFR] = irq_bit | rbv_clear;
via2[gIER] = irq_bit | 0x80;
}
}
/*
* Dispatch Nubus interrupts. We are called as a secondary dispatch by the
* VIA2 dispatcher as a fast interrupt handler.
*/
void via_nubus_irq(int irq, void *dev_id, struct pt_regs *regs)
{
int irq_bit, i;
unsigned char events;
if (!(events = ~via2[gBufA] & nubus_active)) return;
for (i = 0, irq_bit = 1 ; i < 7 ; i++, irq_bit <<= 1) {
if (events & irq_bit) {
via_irq_disable(NUBUS_SOURCE_BASE + i);
mac_do_irq_list(NUBUS_SOURCE_BASE + i, regs);
via_irq_enable(NUBUS_SOURCE_BASE + i);
}
}
}
void via_irq_enable(int irq) {
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
int irq_bit = 1 << irq_idx;
#ifdef DEBUG_IRQUSE
printk("via_irq_enable(%d)\n", irq);
#endif
if (irq_src == 1) {
via1[vIER] = irq_bit | 0x80;
} else if (irq_src == 2) {
/*
* Set vPCR for SCSI interrupts (but not on RBV)
*/
if ((irq_idx == 0) && !rbv_present) {
if (macintosh_config->scsi_type == MAC_SCSI_OLD) {
/* CB2 (IRQ) indep. input, positive edge */
/* CA2 (DRQ) indep. input, positive edge */
via2[vPCR] = 0x66;
} else {
/* CB2 (IRQ) indep. input, negative edge */
/* CA2 (DRQ) indep. input, negative edge */
via2[vPCR] = 0x22;
}
}
via2[gIER] = irq_bit | 0x80;
} else if (irq_src == 7) {
if (rbv_present) {
/* enable the slot interrupt. SIER works like IER. */
via2[rSIER] = IER_SET_BIT(irq_idx);
} else {
/* Make sure the bit is an input, to enable the irq */
via2[vDirA] &= ~irq_bit;
}
nubus_active |= irq_bit;
}
}
void via_irq_disable(int irq) {
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
int irq_bit = 1 << irq_idx;
#ifdef DEBUG_IRQUSE
printk("via_irq_disable(%d)\n", irq);
#endif
if (irq_src == 1) {
via1[vIER] = irq_bit;
} else if (irq_src == 2) {
via2[gIER] = irq_bit;
} else if (irq_src == 7) {
if (rbv_present) {
/* disable the slot interrupt. SIER works like IER. */
via2[rSIER] = IER_CLR_BIT(irq_idx);
} else {
/* disable the nubus irq by changing dir to output */
via2[vDirA] |= irq_bit;
}
nubus_active &= ~irq_bit;
}
}
void via_irq_clear(int irq) {
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
int irq_bit = 1 << irq_idx;
if (irq_src == 1) {
via1[vIFR] = irq_bit;
} else if (irq_src == 2) {
via2[gIFR] = irq_bit | rbv_clear;
} else if (irq_src == 7) {
/* FIXME: hmm.. */
}
}
/*
* Returns nonzero if an interrupt is pending on the given
* VIA/IRQ combination.
*/
int via_irq_pending(int irq)
{
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
int irq_bit = 1 << irq_idx;
if (irq_src == 1) {
return via1[vIFR] & irq_bit;
} else if (irq_src == 2) {
return via2[gIFR] & irq_bit;
} else if (irq_src == 7) {
return ~via2[gBufA] & irq_bit;
}
return 0;
}
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