Linux-2.6.33.2/arch/m68k/mac/via.c
/*
* 6522 Versatile Interface Adapter (VIA)
*
* There are two of these on the Mac II. Some IRQs 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
*
* Additional data is here (the SY6522 was used in the Mac II etc):
* http://www.6502.org/documents/datasheets/synertek/synertek_sy6522.pdf
* http://www.6502.org/documents/datasheets/synertek/synertek_sy6522_programming_reference.pdf
*
* 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/module.h>
#include <asm/bootinfo.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_via.h>
#include <asm/mac_psc.h>
#include <asm/mac_oss.h>
volatile __u8 *via1, *via2;
int rbv_present;
int via_alt_mapping;
EXPORT_SYMBOL(via_alt_mapping);
static __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
* _consistently_ 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)
/* To disable a NuBus slot on Quadras we make that slot IRQ line an output set
* high. On RBV we just use the slot interrupt enable register. On Macs with
* genuine VIA chips we must use nubus_disabled to keep track of disabled slot
* interrupts. When any slot IRQ is disabled we mask the (edge triggered) CA1
* or "SLOTS" interrupt. When no slot is disabled, we unmask the CA1 interrupt.
* So, on genuine VIAs, having more than one NuBus IRQ can mean trouble,
* because closing one of those drivers can mask all of the NuBus interrupts.
* Also, since we can't mask the unregistered slot IRQs on genuine VIAs, it's
* possible to get interrupts from cards that MacOS or the ROM has configured
* but we have not. FWIW, "Designing Cards and Drivers for Macintosh II and
* Macintosh SE", page 9-8, says, a slot IRQ with no driver would crash MacOS.
*/
static u8 nubus_disabled;
void via_debug_dump(void);
irqreturn_t via1_irq(int, void *);
irqreturn_t via2_irq(int, void *);
irqreturn_t via_nubus_irq(int, void *);
void via_irq_enable(int irq);
void via_irq_disable(int irq);
void via_irq_clear(int irq);
extern irqreturn_t mac_scc_dispatch(int, void *);
/*
* 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(KERN_INFO "VIA1 at %p is a 6522 or clone\n", via1);
printk(KERN_INFO "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] &= ~0xC0; /* setup T1 timer with no PB7 output */
via1[vACR] &= ~0x03; /* disable port A & B latches */
/*
* 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;
/* 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. */
via_alt_mapping = 0;
if (macintosh_config->via_type == MAC_VIA_QUADRA)
switch (macintosh_config->ident) {
case MAC_MODEL_C660:
case MAC_MODEL_Q840:
/* not applicable */
break;
case MAC_MODEL_P588:
case MAC_MODEL_TV:
case MAC_MODEL_PB140:
case MAC_MODEL_PB145:
case MAC_MODEL_PB160:
case MAC_MODEL_PB165:
case MAC_MODEL_PB165C:
case MAC_MODEL_PB170:
case MAC_MODEL_PB180:
case MAC_MODEL_PB180C:
case MAC_MODEL_PB190:
case MAC_MODEL_PB520:
/* not yet tested */
break;
default:
via_alt_mapping = 1;
via1[vDirB] |= 0x40;
via1[vBufB] &= ~0x40;
break;
}
/*
* 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] &= ~0xC0; /* setup T1 timer with no PB7 output */
via2[vACR] &= ~0x03; /* disable port A & B latches */
}
/*
* Set vPCR for control line interrupts (but not on RBV)
*/
if (!rbv_present) {
/* For all VIA types, CA1 (SLOTS IRQ) and CB1 (ASC IRQ)
* are made negative edge triggered here.
*/
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;
}
}
}
/*
* Start the 100 Hz clock
*/
void __init via_init_clock(irq_handler_t func)
{
via1[vACR] |= 0x40;
via1[vT1LL] = MAC_CLOCK_LOW;
via1[vT1LH] = MAC_CLOCK_HIGH;
via1[vT1CL] = MAC_CLOCK_LOW;
via1[vT1CH] = MAC_CLOCK_HIGH;
if (request_irq(IRQ_MAC_TIMER_1, func, IRQ_FLG_LOCK, "timer", func))
pr_err("Couldn't register %s interrupt\n", "timer");
}
/*
* Register the interrupt dispatchers for VIA or RBV machines only.
*/
void __init via_register_interrupts(void)
{
if (via_alt_mapping) {
if (request_irq(IRQ_AUTO_1, via1_irq,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "software",
(void *) via1))
pr_err("Couldn't register %s interrupt\n", "software");
if (request_irq(IRQ_AUTO_6, via1_irq,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
(void *) via1))
pr_err("Couldn't register %s interrupt\n", "via1");
} else {
if (request_irq(IRQ_AUTO_1, via1_irq,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "via1",
(void *) via1))
pr_err("Couldn't register %s interrupt\n", "via1");
}
if (request_irq(IRQ_AUTO_2, via2_irq, IRQ_FLG_LOCK|IRQ_FLG_FAST,
"via2", (void *) via2))
pr_err("Couldn't register %s interrupt\n", "via2");
if (!psc_present) {
if (request_irq(IRQ_AUTO_4, mac_scc_dispatch, IRQ_FLG_LOCK,
"scc", mac_scc_dispatch))
pr_err("Couldn't register %s interrupt\n", "scc");
}
if (request_irq(IRQ_MAC_NUBUS, via_nubus_irq,
IRQ_FLG_LOCK|IRQ_FLG_FAST, "nubus", (void *) via2))
pr_err("Couldn't register %s interrupt\n", "nubus");
}
/*
* Debugging dump, used in various places to see what's going on.
*/
void via_debug_dump(void)
{
printk(KERN_DEBUG "VIA1: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
(uint) via1[vDirA], (uint) via1[vDirB], (uint) via1[vACR]);
printk(KERN_DEBUG " PCR = 0x%02X IFR = 0x%02X IER = 0x%02X\n",
(uint) via1[vPCR], (uint) via1[vIFR], (uint) via1[vIER]);
if (oss_present) {
printk(KERN_DEBUG "VIA2: <OSS>\n");
} else if (rbv_present) {
printk(KERN_DEBUG "VIA2: IFR = 0x%02X IER = 0x%02X\n",
(uint) via2[rIFR], (uint) via2[rIER]);
printk(KERN_DEBUG " SIFR = 0x%02X SIER = 0x%02X\n",
(uint) via2[rSIFR], (uint) via2[rSIER]);
} else {
printk(KERN_DEBUG "VIA2: DDRA = 0x%02X DDRB = 0x%02X ACR = 0x%02X\n",
(uint) via2[vDirA], (uint) via2[vDirB],
(uint) via2[vACR]);
printk(KERN_DEBUG " 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)
{
/* unlock nubus transactions */
if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
(macintosh_config->adb_type != MAC_ADB_PB2)) {
/* set the line to be an output on non-RBV machines */
if (!rbv_present)
via2[vDirB] |= 0x02;
/* this seems to be an ADB bit on PMU machines */
/* according to MkLinux. -- jmt */
via2[gBufB] |= 0x02;
}
/* Disable all the slot interrupts (where possible). */
switch (macintosh_config->via_type) {
case MAC_VIA_II:
/* Just make the port A lines inputs. */
switch(macintosh_config->ident) {
case MAC_MODEL_II:
case MAC_MODEL_IIX:
case MAC_MODEL_IICX:
case MAC_MODEL_SE30:
/* The top two bits are RAM size outputs. */
via2[vDirA] &= 0xC0;
break;
default:
via2[vDirA] &= 0x80;
}
break;
case MAC_VIA_IIci:
/* RBV. Disable all the slot interrupts. SIER works like IER. */
via2[rSIER] = 0x7F;
break;
case MAC_VIA_QUADRA:
/* Disable the inactive slot interrupts by making those lines outputs. */
if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
(macintosh_config->adb_type != MAC_ADB_PB2)) {
via2[vBufA] |= 0x7F;
via2[vDirA] |= 0x7F;
}
break;
}
}
/*
* The generic VIA interrupt routines (shamelessly stolen from Alan Cox's
* via6522.c :-), disable/pending masks added.
*/
irqreturn_t via1_irq(int irq, void *dev_id)
{
int irq_num;
unsigned char irq_bit, events;
events = via1[vIFR] & via1[vIER] & 0x7F;
if (!events)
return IRQ_NONE;
irq_num = VIA1_SOURCE_BASE;
irq_bit = 1;
do {
if (events & irq_bit) {
via1[vIFR] = irq_bit;
m68k_handle_int(irq_num);
}
++irq_num;
irq_bit <<= 1;
} while (events >= irq_bit);
return IRQ_HANDLED;
}
irqreturn_t via2_irq(int irq, void *dev_id)
{
int irq_num;
unsigned char irq_bit, events;
events = via2[gIFR] & via2[gIER] & 0x7F;
if (!events)
return IRQ_NONE;
irq_num = VIA2_SOURCE_BASE;
irq_bit = 1;
do {
if (events & irq_bit) {
via2[gIFR] = irq_bit | rbv_clear;
m68k_handle_int(irq_num);
}
++irq_num;
irq_bit <<= 1;
} while (events >= irq_bit);
return IRQ_HANDLED;
}
/*
* Dispatch Nubus interrupts. We are called as a secondary dispatch by the
* VIA2 dispatcher as a fast interrupt handler.
*/
irqreturn_t via_nubus_irq(int irq, void *dev_id)
{
int slot_irq;
unsigned char slot_bit, events;
events = ~via2[gBufA] & 0x7F;
if (rbv_present)
events &= via2[rSIER];
else
events &= ~via2[vDirA];
if (!events)
return IRQ_NONE;
do {
slot_irq = IRQ_NUBUS_F;
slot_bit = 0x40;
do {
if (events & slot_bit) {
events &= ~slot_bit;
m68k_handle_int(slot_irq);
}
--slot_irq;
slot_bit >>= 1;
} while (events);
/* clear the CA1 interrupt and make certain there's no more. */
via2[gIFR] = 0x02 | rbv_clear;
events = ~via2[gBufA] & 0x7F;
if (rbv_present)
events &= via2[rSIER];
else
events &= ~via2[vDirA];
} while (events);
return IRQ_HANDLED;
}
void via_irq_enable(int irq) {
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
#ifdef DEBUG_IRQUSE
printk(KERN_DEBUG "via_irq_enable(%d)\n", irq);
#endif
if (irq_src == 1) {
via1[vIER] = IER_SET_BIT(irq_idx);
} else if (irq_src == 2) {
if (irq != IRQ_MAC_NUBUS || nubus_disabled == 0)
via2[gIER] = IER_SET_BIT(irq_idx);
} else if (irq_src == 7) {
switch (macintosh_config->via_type) {
case MAC_VIA_II:
nubus_disabled &= ~(1 << irq_idx);
/* Enable the CA1 interrupt when no slot is disabled. */
if (!nubus_disabled)
via2[gIER] = IER_SET_BIT(1);
break;
case MAC_VIA_IIci:
/* On RBV, enable the slot interrupt.
* SIER works like IER.
*/
via2[rSIER] = IER_SET_BIT(irq_idx);
break;
case MAC_VIA_QUADRA:
/* Make the port A line an input to enable the slot irq.
* But not on PowerBooks, that's ADB.
*/
if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
(macintosh_config->adb_type != MAC_ADB_PB2))
via2[vDirA] &= ~(1 << irq_idx);
break;
}
}
}
void via_irq_disable(int irq) {
int irq_src = IRQ_SRC(irq);
int irq_idx = IRQ_IDX(irq);
#ifdef DEBUG_IRQUSE
printk(KERN_DEBUG "via_irq_disable(%d)\n", irq);
#endif
if (irq_src == 1) {
via1[vIER] = IER_CLR_BIT(irq_idx);
} else if (irq_src == 2) {
via2[gIER] = IER_CLR_BIT(irq_idx);
} else if (irq_src == 7) {
switch (macintosh_config->via_type) {
case MAC_VIA_II:
nubus_disabled |= 1 << irq_idx;
if (nubus_disabled)
via2[gIER] = IER_CLR_BIT(1);
break;
case MAC_VIA_IIci:
via2[rSIER] = IER_CLR_BIT(irq_idx);
break;
case MAC_VIA_QUADRA:
if ((macintosh_config->adb_type != MAC_ADB_PB1) &&
(macintosh_config->adb_type != MAC_ADB_PB2))
via2[vDirA] |= 1 << irq_idx;
break;
}
}
}
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: There is no way to clear an individual nubus slot
* IRQ flag, other than getting the device to do it.
*/
}
}
/*
* 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) {
/* Always 0 for MAC_VIA_QUADRA if the slot irq is disabled. */
return ~via2[gBufA] & irq_bit;
}
return 0;
}
void via1_set_head(int head)
{
if (head == 0)
via1[vBufA] &= ~VIA1A_vHeadSel;
else
via1[vBufA] |= VIA1A_vHeadSel;
}
EXPORT_SYMBOL(via1_set_head);