--- /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;
+}