| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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 <linux/irq.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; |
| |
| /* |
| * On Macs with a genuine VIA chip there is no way to mask an individual slot |
| * interrupt. This limitation also seems to apply to VIA clone logic cores in |
| * Quadra-like ASICs. (RBV and OSS machines don't have this limitation.) |
| * |
| * We used to fake it by configuring the relevant VIA pin as an output |
| * (to mask the interrupt) or input (to unmask). That scheme did not work on |
| * (at least) the Quadra 700. A NuBus card's /NMRQ signal is an open-collector |
| * circuit (see Designing Cards and Drivers for Macintosh II and Macintosh SE, |
| * p. 10-11 etc) but VIA outputs are not (see datasheet). |
| * |
| * Driving these outputs high must cause the VIA to source current and the |
| * card to sink current when it asserts /NMRQ. Current will flow but the pin |
| * voltage is uncertain and so the /NMRQ condition may still cause a transition |
| * at the VIA2 CA1 input (which explains the lost interrupts). A side effect |
| * is that a disabled slot IRQ can never be tested as pending or not. |
| * |
| * Driving these outputs low doesn't work either. All the slot /NMRQ lines are |
| * (active low) OR'd together to generate the CA1 (aka "SLOTS") interrupt (see |
| * The Guide To Macintosh Family Hardware, 2nd edition p. 167). If we drive a |
| * disabled /NMRQ line low, the falling edge immediately triggers a CA1 |
| * interrupt and all slot interrupts after that will generate no transition |
| * and therefore no interrupt, even after being re-enabled. |
| * |
| * So we make the VIA port A I/O lines inputs and use nubus_disabled to keep |
| * track of their states. When any slot IRQ becomes disabled we mask the CA1 |
| * umbrella interrupt. Only when all slot IRQs become enabled do we unmask |
| * the CA1 interrupt. It must remain enabled even when cards have no interrupt |
| * handler registered. Drivers must therefore disable a slot interrupt at the |
| * device before they call free_irq (like shared and autovector interrupts). |
| * |
| * There is also a related problem when MacOS is used to boot Linux. A network |
| * card brought up by a MacOS driver may raise an interrupt while Linux boots. |
| * This can be fatal since it can't be handled until the right driver loads |
| * (if such a driver exists at all). Apparently related to this hardware |
| * limitation, "Designing Cards and Drivers", p. 9-8, says that a slot |
| * interrupt with no driver would crash MacOS (the book was written before |
| * the appearance of Macs with RBV or OSS). |
| */ |
| |
| static u8 nubus_disabled; |
| |
| void via_debug_dump(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; |
| |
| if ((macintosh_config->via_type == MAC_VIA_QUADRA) && |
| (macintosh_config->adb_type != MAC_ADB_PB1) && |
| (macintosh_config->adb_type != MAC_ADB_PB2) && |
| (macintosh_config->ident != MAC_MODEL_C660) && |
| (macintosh_config->ident != MAC_MODEL_Q840)) { |
| via_alt_mapping = 1; |
| via1[vDirB] |= 0x40; |
| via1[vBufB] &= ~0x40; |
| } else { |
| via_alt_mapping = 0; |
| } |
| |
| /* |
| * 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 */ |
| } |
| |
| /* Everything below this point is VIA2 only... */ |
| |
| if (rbv_present) |
| return; |
| |
| /* |
| * Set vPCR for control line interrupts. |
| * |
| * CA1 (SLOTS IRQ), CB1 (ASC IRQ): negative edge trigger. |
| * |
| * Macs with ESP SCSI have a negative edge triggered SCSI interrupt. |
| * Testing reveals that PowerBooks do too. However, the SE/30 |
| * schematic diagram shows an active high NCR5380 IRQ line. |
| */ |
| |
| pr_debug("VIA2 vPCR is 0x%02X\n", via2[vPCR]); |
| if (macintosh_config->via_type == MAC_VIA_II) { |
| /* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, pos. edge */ |
| via2[vPCR] = 0x66; |
| } else { |
| /* CA2 (SCSI DRQ), CB2 (SCSI IRQ): indep. input, neg. edge */ |
| via2[vPCR] = 0x22; |
| } |
| } |
| |
| /* |
| * 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]); |
| } |
| } |
| |
| /* |
| * 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 the slot interrupts. On some hardware that's not possible. |
| * On some hardware it's unclear what all of these I/O lines do. |
| */ |
| |
| switch (macintosh_config->via_type) { |
| case MAC_VIA_II: |
| case MAC_VIA_QUADRA: |
| pr_debug("VIA2 vDirA is 0x%02X\n", via2[vDirA]); |
| break; |
| case MAC_VIA_IICI: |
| /* RBV. Disable all the slot interrupts. SIER works like IER. */ |
| via2[rSIER] = 0x7F; |
| break; |
| } |
| } |
| |
| void via_nubus_irq_startup(int irq) |
| { |
| int irq_idx = IRQ_IDX(irq); |
| |
| switch (macintosh_config->via_type) { |
| case MAC_VIA_II: |
| case MAC_VIA_QUADRA: |
| /* Make the port A line an input. Probably redundant. */ |
| if (macintosh_config->via_type == MAC_VIA_II) { |
| /* The top two bits are RAM size outputs. */ |
| via2[vDirA] &= 0xC0 | ~(1 << irq_idx); |
| } else { |
| /* Allow NuBus slots 9 through F. */ |
| via2[vDirA] &= 0x80 | ~(1 << irq_idx); |
| } |
| /* fall through */ |
| case MAC_VIA_IICI: |
| via_irq_enable(irq); |
| break; |
| } |
| } |
| |
| void via_nubus_irq_shutdown(int irq) |
| { |
| switch (macintosh_config->via_type) { |
| case MAC_VIA_II: |
| case MAC_VIA_QUADRA: |
| /* Ensure that the umbrella CA1 interrupt remains enabled. */ |
| via_irq_enable(irq); |
| break; |
| case MAC_VIA_IICI: |
| via_irq_disable(irq); |
| break; |
| } |
| } |
| |
| /* |
| * The generic VIA interrupt routines (shamelessly stolen from Alan Cox's |
| * via6522.c :-), disable/pending masks added. |
| */ |
| |
| #define VIA_TIMER_1_INT BIT(6) |
| |
| void via1_irq(struct irq_desc *desc) |
| { |
| int irq_num; |
| unsigned char irq_bit, events; |
| |
| events = via1[vIFR] & via1[vIER] & 0x7F; |
| if (!events) |
| return; |
| |
| irq_num = IRQ_MAC_TIMER_1; |
| irq_bit = VIA_TIMER_1_INT; |
| if (events & irq_bit) { |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| via1[vIFR] = irq_bit; |
| generic_handle_irq(irq_num); |
| local_irq_restore(flags); |
| |
| events &= ~irq_bit; |
| if (!events) |
| return; |
| } |
| |
| irq_num = VIA1_SOURCE_BASE; |
| irq_bit = 1; |
| do { |
| if (events & irq_bit) { |
| via1[vIFR] = irq_bit; |
| generic_handle_irq(irq_num); |
| } |
| ++irq_num; |
| irq_bit <<= 1; |
| } while (events >= irq_bit); |
| } |
| |
| static void via2_irq(struct irq_desc *desc) |
| { |
| int irq_num; |
| unsigned char irq_bit, events; |
| |
| events = via2[gIFR] & via2[gIER] & 0x7F; |
| if (!events) |
| return; |
| |
| irq_num = VIA2_SOURCE_BASE; |
| irq_bit = 1; |
| do { |
| if (events & irq_bit) { |
| via2[gIFR] = irq_bit | rbv_clear; |
| generic_handle_irq(irq_num); |
| } |
| ++irq_num; |
| irq_bit <<= 1; |
| } while (events >= irq_bit); |
| } |
| |
| /* |
| * Dispatch Nubus interrupts. We are called as a secondary dispatch by the |
| * VIA2 dispatcher as a fast interrupt handler. |
| */ |
| |
| static void via_nubus_irq(struct irq_desc *desc) |
| { |
| 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; |
| |
| do { |
| slot_irq = IRQ_NUBUS_F; |
| slot_bit = 0x40; |
| do { |
| if (events & slot_bit) { |
| events &= ~slot_bit; |
| generic_handle_irq(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); |
| } |
| |
| /* |
| * Register the interrupt dispatchers for VIA or RBV machines only. |
| */ |
| |
| void __init via_register_interrupts(void) |
| { |
| if (via_alt_mapping) { |
| /* software interrupt */ |
| irq_set_chained_handler(IRQ_AUTO_1, via1_irq); |
| /* via1 interrupt */ |
| irq_set_chained_handler(IRQ_AUTO_6, via1_irq); |
| } else { |
| irq_set_chained_handler(IRQ_AUTO_1, via1_irq); |
| } |
| irq_set_chained_handler(IRQ_AUTO_2, via2_irq); |
| irq_set_chained_handler(IRQ_MAC_NUBUS, via_nubus_irq); |
| } |
| |
| void via_irq_enable(int irq) { |
| int irq_src = IRQ_SRC(irq); |
| int irq_idx = IRQ_IDX(irq); |
| |
| 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: |
| case MAC_VIA_QUADRA: |
| 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; |
| } |
| } |
| } |
| |
| void via_irq_disable(int irq) { |
| int irq_src = IRQ_SRC(irq); |
| int irq_idx = IRQ_IDX(irq); |
| |
| 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: |
| case MAC_VIA_QUADRA: |
| 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; |
| } |
| } |
| } |
| |
| void via1_set_head(int head) |
| { |
| if (head == 0) |
| via1[vBufA] &= ~VIA1A_vHeadSel; |
| else |
| via1[vBufA] |= VIA1A_vHeadSel; |
| } |
| EXPORT_SYMBOL(via1_set_head); |
| |
| int via2_scsi_drq_pending(void) |
| { |
| return via2[gIFR] & (1 << IRQ_IDX(IRQ_MAC_SCSIDRQ)); |
| } |
| EXPORT_SYMBOL(via2_scsi_drq_pending); |
| |
| /* timer and clock source */ |
| |
| #define VIA_CLOCK_FREQ 783360 /* VIA "phase 2" clock in Hz */ |
| #define VIA_TIMER_INTERVAL (1000000 / HZ) /* microseconds per jiffy */ |
| #define VIA_TIMER_CYCLES (VIA_CLOCK_FREQ / HZ) /* clock cycles per jiffy */ |
| |
| #define VIA_TC (VIA_TIMER_CYCLES - 2) /* including 0 and -1 */ |
| #define VIA_TC_LOW (VIA_TC & 0xFF) |
| #define VIA_TC_HIGH (VIA_TC >> 8) |
| |
| void __init via_init_clock(irq_handler_t timer_routine) |
| { |
| if (request_irq(IRQ_MAC_TIMER_1, timer_routine, 0, "timer", NULL)) { |
| pr_err("Couldn't register %s interrupt\n", "timer"); |
| return; |
| } |
| |
| via1[vT1LL] = VIA_TC_LOW; |
| via1[vT1LH] = VIA_TC_HIGH; |
| via1[vT1CL] = VIA_TC_LOW; |
| via1[vT1CH] = VIA_TC_HIGH; |
| via1[vACR] |= 0x40; |
| } |
| |
| u32 mac_gettimeoffset(void) |
| { |
| unsigned long flags; |
| u8 count_high; |
| u16 count, offset = 0; |
| |
| /* |
| * Timer counter wrap-around is detected with the timer interrupt flag |
| * but reading the counter low byte (vT1CL) would reset the flag. |
| * Also, accessing both counter registers is essentially a data race. |
| * These problems are avoided by ignoring the low byte. Clock accuracy |
| * is 256 times worse (error can reach 0.327 ms) but CPU overhead is |
| * reduced by avoiding slow VIA register accesses. |
| */ |
| |
| local_irq_save(flags); |
| count_high = via1[vT1CH]; |
| if (count_high == 0xFF) |
| count_high = 0; |
| if (count_high > 0 && (via1[vIFR] & VIA_TIMER_1_INT)) |
| offset = VIA_TIMER_CYCLES; |
| local_irq_restore(flags); |
| |
| count = count_high << 8; |
| count = VIA_TIMER_CYCLES - count + offset; |
| |
| return ((count * VIA_TIMER_INTERVAL) / VIA_TIMER_CYCLES) * 1000; |
| } |