diff options
author | bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162> | 2004-03-14 12:20:30 +0000 |
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committer | bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162> | 2004-03-14 12:20:30 +0000 |
commit | 80cabfad16384ca47f783a7c494bd1c3c6e3c4bc (patch) | |
tree | ad2965750e60527e38280de84ab1d6d01d33ef68 /hw/i8254.c | |
parent | 38ca2abc2eb0fc8edd067420b3fcfa10ffa0054b (diff) |
separated more devices from emulator
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@656 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'hw/i8254.c')
-rw-r--r-- | hw/i8254.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/hw/i8254.c b/hw/i8254.c new file mode 100644 index 0000000000..7dc5f3c25f --- /dev/null +++ b/hw/i8254.c @@ -0,0 +1,297 @@ +/* + * 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 <stdlib.h> +#include <stdio.h> +#include <stdarg.h> +#include <string.h> +#include <getopt.h> +#include <inttypes.h> +#include <unistd.h> +#include <sys/mman.h> +#include <fcntl.h> +#include <signal.h> +#include <time.h> +#include <sys/time.h> +#include <malloc.h> +#include <termios.h> +#include <sys/poll.h> +#include <errno.h> +#include <sys/wait.h> +#include <netinet/in.h> + +#include "cpu.h" +#include "vl.h" + +#define RW_STATE_LSB 0 +#define RW_STATE_MSB 1 +#define RW_STATE_WORD0 2 +#define RW_STATE_WORD1 3 +#define RW_STATE_LATCHED_WORD0 4 +#define RW_STATE_LATCHED_WORD1 5 + +PITChannelState pit_channels[3]; + +static int pit_get_count(PITChannelState *s) +{ + uint64_t d; + int counter; + + d = muldiv64(cpu_get_ticks() - 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 */ +int pit_get_out(PITChannelState *s) +{ + uint64_t d; + int out; + + d = muldiv64(cpu_get_ticks() - 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; +} + +/* get the number of 0 to 1 transitions we had since we call this + function */ +/* XXX: maybe better to use ticks precision to avoid getting edges + twice if checks are done at very small intervals */ +int pit_get_out_edges(PITChannelState *s) +{ + uint64_t d1, d2; + int64_t ticks; + int ret, v; + + ticks = cpu_get_ticks(); + d1 = muldiv64(s->count_last_edge_check_time - s->count_load_time, + PIT_FREQ, ticks_per_sec); + d2 = muldiv64(ticks - s->count_load_time, + PIT_FREQ, ticks_per_sec); + s->count_last_edge_check_time = ticks; + switch(s->mode) { + default: + case 0: + if (d1 < s->count && d2 >= s->count) + ret = 1; + else + ret = 0; + break; + case 1: + ret = 0; + break; + case 2: + d1 /= s->count; + d2 /= s->count; + ret = d2 - d1; + break; + case 3: + v = s->count - ((s->count + 1) >> 1); + d1 = (d1 + v) / s->count; + d2 = (d2 + v) / s->count; + ret = d2 - d1; + break; + case 4: + case 5: + if (d1 < s->count && d2 >= s->count) + ret = 1; + else + ret = 0; + break; + } + return ret; +} + +/* val must be 0 or 1 */ +void pit_set_gate(PITChannelState *s, int val) +{ + 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 = cpu_get_ticks(); + s->count_last_edge_check_time = s->count_load_time; + } + break; + case 2: + case 3: + if (s->gate < val) { + /* restart counting on rising edge */ + s->count_load_time = cpu_get_ticks(); + s->count_last_edge_check_time = s->count_load_time; + } + /* XXX: disable/enable counting */ + break; + } + s->gate = val; +} + +static inline void pit_load_count(PITChannelState *s, int val) +{ + if (val == 0) + val = 0x10000; + s->count_load_time = cpu_get_ticks(); + s->count_last_edge_check_time = s->count_load_time; + s->count = val; + if (s == &pit_channels[0] && val <= pit_min_timer_count) { + fprintf(stderr, + "\nWARNING: qemu: on your system, accurate timer emulation is impossible if its frequency is more than %d Hz. If using a 2.6 guest Linux kernel, you must patch asm/param.h to change HZ from 1000 to 100.\n\n", + PIT_FREQ / pit_min_timer_count); + } +} + +void pit_ioport_write(CPUState *env, uint32_t addr, uint32_t val) +{ + int channel, access; + PITChannelState *s; + + addr &= 3; + if (addr == 3) { + channel = val >> 6; + if (channel == 3) + return; + s = &pit_channels[channel]; + access = (val >> 4) & 3; + switch(access) { + case 0: + s->latched_count = pit_get_count(s); + s->rw_state = RW_STATE_LATCHED_WORD0; + break; + default: + s->mode = (val >> 1) & 7; + s->bcd = val & 1; + s->rw_state = access - 1 + RW_STATE_LSB; + break; + } + } else { + s = &pit_channels[addr]; + switch(s->rw_state) { + 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: + case RW_STATE_WORD1: + if (s->rw_state & 1) { + pit_load_count(s, (s->latched_count & 0xff) | (val << 8)); + } else { + s->latched_count = val; + } + s->rw_state ^= 1; + break; + } + } +} + +uint32_t pit_ioport_read(CPUState *env, uint32_t addr) +{ + int ret, count; + PITChannelState *s; + + addr &= 3; + s = &pit_channels[addr]; + switch(s->rw_state) { + case RW_STATE_LSB: + case RW_STATE_MSB: + case RW_STATE_WORD0: + case RW_STATE_WORD1: + count = pit_get_count(s); + if (s->rw_state & 1) + ret = (count >> 8) & 0xff; + else + ret = count & 0xff; + if (s->rw_state & 2) + s->rw_state ^= 1; + break; + default: + case RW_STATE_LATCHED_WORD0: + case RW_STATE_LATCHED_WORD1: + if (s->rw_state & 1) + ret = s->latched_count >> 8; + else + ret = s->latched_count & 0xff; + s->rw_state ^= 1; + break; + } + return ret; +} + +void pit_init(void) +{ + 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); + } + + register_ioport_write(0x40, 4, pit_ioport_write, 1); + register_ioport_read(0x40, 3, pit_ioport_read, 1); +} + |