diff -r ffa851df0825 -r 2fb8b9db1c86 symbian-qemu-0.9.1-12/qemu-symbian-svp/hw/i8254.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/symbian-qemu-0.9.1-12/qemu-symbian-svp/hw/i8254.c Fri Jul 31 15:01:17 2009 +0100 @@ -0,0 +1,506 @@ +/* + * QEMU 8253/8254 interval timer emulation + * + * Copyright (c) 2003-2004 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include "hw.h" +#include "pc.h" +#include "isa.h" +#include "qemu-timer.h" + +//#define DEBUG_PIT + +#define RW_STATE_LSB 1 +#define RW_STATE_MSB 2 +#define RW_STATE_WORD0 3 +#define RW_STATE_WORD1 4 + +typedef struct PITChannelState { + int count; /* can be 65536 */ + uint16_t latched_count; + uint8_t count_latched; + uint8_t status_latched; + uint8_t status; + uint8_t read_state; + uint8_t write_state; + uint8_t write_latch; + uint8_t rw_mode; + uint8_t mode; + uint8_t bcd; /* not supported */ + uint8_t gate; /* timer start */ + int64_t count_load_time; + /* irq handling */ + int64_t next_transition_time; + QEMUTimer *irq_timer; + qemu_irq irq; +} PITChannelState; + +struct PITState { + PITChannelState channels[3]; +}; + +static PITState pit_state; + +static void pit_irq_timer_update(PITChannelState *s, int64_t current_time); + +static int pit_get_count(PITChannelState *s) +{ + uint64_t d; + int counter; + + d = muldiv64(qemu_get_clock(vm_clock) - s->count_load_time, PIT_FREQ, ticks_per_sec); + switch(s->mode) { + case 0: + case 1: + case 4: + case 5: + counter = (s->count - d) & 0xffff; + break; + case 3: + /* XXX: may be incorrect for odd counts */ + counter = s->count - ((2 * d) % s->count); + break; + default: + counter = s->count - (d % s->count); + break; + } + return counter; +} + +/* get pit output bit */ +static int pit_get_out1(PITChannelState *s, int64_t current_time) +{ + uint64_t d; + int out; + + d = muldiv64(current_time - s->count_load_time, PIT_FREQ, ticks_per_sec); + switch(s->mode) { + default: + case 0: + out = (d >= s->count); + break; + case 1: + out = (d < s->count); + break; + case 2: + if ((d % s->count) == 0 && d != 0) + out = 1; + else + out = 0; + break; + case 3: + out = (d % s->count) < ((s->count + 1) >> 1); + break; + case 4: + case 5: + out = (d == s->count); + break; + } + return out; +} + +int pit_get_out(PITState *pit, int channel, int64_t current_time) +{ + PITChannelState *s = &pit->channels[channel]; + return pit_get_out1(s, current_time); +} + +/* return -1 if no transition will occur. */ +static int64_t pit_get_next_transition_time(PITChannelState *s, + int64_t current_time) +{ + uint64_t d, next_time, base; + int period2; + + d = muldiv64(current_time - s->count_load_time, PIT_FREQ, ticks_per_sec); + switch(s->mode) { + default: + case 0: + case 1: + if (d < s->count) + next_time = s->count; + else + return -1; + break; + case 2: + base = (d / s->count) * s->count; + if ((d - base) == 0 && d != 0) + next_time = base + s->count; + else + next_time = base + s->count + 1; + break; + case 3: + base = (d / s->count) * s->count; + period2 = ((s->count + 1) >> 1); + if ((d - base) < period2) + next_time = base + period2; + else + next_time = base + s->count; + break; + case 4: + case 5: + if (d < s->count) + next_time = s->count; + else if (d == s->count) + next_time = s->count + 1; + else + return -1; + break; + } + /* convert to timer units */ + next_time = s->count_load_time + muldiv64(next_time, ticks_per_sec, PIT_FREQ); + /* fix potential rounding problems */ + /* XXX: better solution: use a clock at PIT_FREQ Hz */ + if (next_time <= current_time) + next_time = current_time + 1; + return next_time; +} + +/* val must be 0 or 1 */ +void pit_set_gate(PITState *pit, int channel, int val) +{ + PITChannelState *s = &pit->channels[channel]; + + switch(s->mode) { + default: + case 0: + case 4: + /* XXX: just disable/enable counting */ + break; + case 1: + case 5: + if (s->gate < val) { + /* restart counting on rising edge */ + s->count_load_time = qemu_get_clock(vm_clock); + pit_irq_timer_update(s, s->count_load_time); + } + break; + case 2: + case 3: + if (s->gate < val) { + /* restart counting on rising edge */ + s->count_load_time = qemu_get_clock(vm_clock); + pit_irq_timer_update(s, s->count_load_time); + } + /* XXX: disable/enable counting */ + break; + } + s->gate = val; +} + +int pit_get_gate(PITState *pit, int channel) +{ + PITChannelState *s = &pit->channels[channel]; + return s->gate; +} + +int pit_get_initial_count(PITState *pit, int channel) +{ + PITChannelState *s = &pit->channels[channel]; + return s->count; +} + +int pit_get_mode(PITState *pit, int channel) +{ + PITChannelState *s = &pit->channels[channel]; + return s->mode; +} + +static inline void pit_load_count(PITChannelState *s, int val) +{ + if (val == 0) + val = 0x10000; + s->count_load_time = qemu_get_clock(vm_clock); + s->count = val; + pit_irq_timer_update(s, s->count_load_time); +} + +/* if already latched, do not latch again */ +static void pit_latch_count(PITChannelState *s) +{ + if (!s->count_latched) { + s->latched_count = pit_get_count(s); + s->count_latched = s->rw_mode; + } +} + +static void pit_ioport_write(void *opaque, uint32_t addr, uint32_t val) +{ + PITState *pit = opaque; + int channel, access; + PITChannelState *s; + + addr &= 3; + if (addr == 3) { + channel = val >> 6; + if (channel == 3) { + /* read back command */ + for(channel = 0; channel < 3; channel++) { + s = &pit->channels[channel]; + if (val & (2 << channel)) { + if (!(val & 0x20)) { + pit_latch_count(s); + } + if (!(val & 0x10) && !s->status_latched) { + /* status latch */ + /* XXX: add BCD and null count */ + s->status = (pit_get_out1(s, qemu_get_clock(vm_clock)) << 7) | + (s->rw_mode << 4) | + (s->mode << 1) | + s->bcd; + s->status_latched = 1; + } + } + } + } else { + s = &pit->channels[channel]; + access = (val >> 4) & 3; + if (access == 0) { + pit_latch_count(s); + } else { + s->rw_mode = access; + s->read_state = access; + s->write_state = access; + + s->mode = (val >> 1) & 7; + s->bcd = val & 1; + /* XXX: update irq timer ? */ + } + } + } else { + s = &pit->channels[addr]; + switch(s->write_state) { + default: + case RW_STATE_LSB: + pit_load_count(s, val); + break; + case RW_STATE_MSB: + pit_load_count(s, val << 8); + break; + case RW_STATE_WORD0: + s->write_latch = val; + s->write_state = RW_STATE_WORD1; + break; + case RW_STATE_WORD1: + pit_load_count(s, s->write_latch | (val << 8)); + s->write_state = RW_STATE_WORD0; + break; + } + } +} + +static uint32_t pit_ioport_read(void *opaque, uint32_t addr) +{ + PITState *pit = opaque; + int ret, count; + PITChannelState *s; + + addr &= 3; + s = &pit->channels[addr]; + if (s->status_latched) { + s->status_latched = 0; + ret = s->status; + } else if (s->count_latched) { + switch(s->count_latched) { + default: + case RW_STATE_LSB: + ret = s->latched_count & 0xff; + s->count_latched = 0; + break; + case RW_STATE_MSB: + ret = s->latched_count >> 8; + s->count_latched = 0; + break; + case RW_STATE_WORD0: + ret = s->latched_count & 0xff; + s->count_latched = RW_STATE_MSB; + break; + } + } else { + switch(s->read_state) { + default: + case RW_STATE_LSB: + count = pit_get_count(s); + ret = count & 0xff; + break; + case RW_STATE_MSB: + count = pit_get_count(s); + ret = (count >> 8) & 0xff; + break; + case RW_STATE_WORD0: + count = pit_get_count(s); + ret = count & 0xff; + s->read_state = RW_STATE_WORD1; + break; + case RW_STATE_WORD1: + count = pit_get_count(s); + ret = (count >> 8) & 0xff; + s->read_state = RW_STATE_WORD0; + break; + } + } + return ret; +} + +static void pit_irq_timer_update(PITChannelState *s, int64_t current_time) +{ + int64_t expire_time; + int irq_level; + + if (!s->irq_timer) + return; + expire_time = pit_get_next_transition_time(s, current_time); + irq_level = pit_get_out1(s, current_time); + qemu_set_irq(s->irq, irq_level); +#ifdef DEBUG_PIT + printf("irq_level=%d next_delay=%f\n", + irq_level, + (double)(expire_time - current_time) / ticks_per_sec); +#endif + s->next_transition_time = expire_time; + if (expire_time != -1) + qemu_mod_timer(s->irq_timer, expire_time); + else + qemu_del_timer(s->irq_timer); +} + +static void pit_irq_timer(void *opaque) +{ + PITChannelState *s = opaque; + + pit_irq_timer_update(s, s->next_transition_time); +} + +static void pit_save(QEMUFile *f, void *opaque) +{ + PITState *pit = opaque; + PITChannelState *s; + int i; + + for(i = 0; i < 3; i++) { + s = &pit->channels[i]; + qemu_put_be32(f, s->count); + qemu_put_be16s(f, &s->latched_count); + qemu_put_8s(f, &s->count_latched); + qemu_put_8s(f, &s->status_latched); + qemu_put_8s(f, &s->status); + qemu_put_8s(f, &s->read_state); + qemu_put_8s(f, &s->write_state); + qemu_put_8s(f, &s->write_latch); + qemu_put_8s(f, &s->rw_mode); + qemu_put_8s(f, &s->mode); + qemu_put_8s(f, &s->bcd); + qemu_put_8s(f, &s->gate); + qemu_put_be64(f, s->count_load_time); + if (s->irq_timer) { + qemu_put_be64(f, s->next_transition_time); + qemu_put_timer(f, s->irq_timer); + } + } +} + +static int pit_load(QEMUFile *f, void *opaque, int version_id) +{ + PITState *pit = opaque; + PITChannelState *s; + int i; + + if (version_id != 1) + return -EINVAL; + + for(i = 0; i < 3; i++) { + s = &pit->channels[i]; + s->count=qemu_get_be32(f); + qemu_get_be16s(f, &s->latched_count); + qemu_get_8s(f, &s->count_latched); + qemu_get_8s(f, &s->status_latched); + qemu_get_8s(f, &s->status); + qemu_get_8s(f, &s->read_state); + qemu_get_8s(f, &s->write_state); + qemu_get_8s(f, &s->write_latch); + qemu_get_8s(f, &s->rw_mode); + qemu_get_8s(f, &s->mode); + qemu_get_8s(f, &s->bcd); + qemu_get_8s(f, &s->gate); + s->count_load_time=qemu_get_be64(f); + if (s->irq_timer) { + s->next_transition_time=qemu_get_be64(f); + qemu_get_timer(f, s->irq_timer); + } + } + return 0; +} + +static void pit_reset(void *opaque) +{ + PITState *pit = opaque; + PITChannelState *s; + int i; + + for(i = 0;i < 3; i++) { + s = &pit->channels[i]; + s->mode = 3; + s->gate = (i != 2); + pit_load_count(s, 0); + } +} + +/* When HPET is operating in legacy mode, i8254 timer0 is disabled */ +void hpet_pit_disable(void) { + PITChannelState *s; + s = &pit_state.channels[0]; + qemu_del_timer(s->irq_timer); +} + +/* When HPET is reset or leaving legacy mode, it must reenable i8254 + * timer 0 + */ + +void hpet_pit_enable(void) +{ + PITState *pit = &pit_state; + PITChannelState *s; + s = &pit->channels[0]; + s->mode = 3; + s->gate = 1; + pit_load_count(s, 0); +} + +PITState *pit_init(int base, qemu_irq irq) +{ + PITState *pit = &pit_state; + PITChannelState *s; + + s = &pit->channels[0]; + /* the timer 0 is connected to an IRQ */ + s->irq_timer = qemu_new_timer(vm_clock, pit_irq_timer, s); + s->irq = irq; + + register_savevm("i8254", base, 1, pit_save, pit_load, pit); + + qemu_register_reset(pit_reset, pit); + register_ioport_write(base, 4, 1, pit_ioport_write, pit); + register_ioport_read(base, 3, 1, pit_ioport_read, pit); + + pit_reset(pit); + + return pit; +}