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/*
* QEMU PC speaker emulation
*
* Copyright (c) 2006 Joachim Henke
*
* 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 "vl.h"
#define PCSPK_BUF_LEN 1792
#define PCSPK_SAMPLE_RATE 32000
#define PCSPK_MAX_FREQ (PCSPK_SAMPLE_RATE >> 1)
#define PCSPK_MIN_COUNT ((PIT_FREQ + PCSPK_MAX_FREQ - 1) / PCSPK_MAX_FREQ)
typedef struct {
uint8_t sample_buf[PCSPK_BUF_LEN];
QEMUSoundCard card;
SWVoiceOut *voice;
PITState *pit;
unsigned int pit_count;
unsigned int samples;
unsigned int play_pos;
int data_on;
int dummy_refresh_clock;
} PCSpkState;
static const char *s_spk = "pcspk";
static PCSpkState pcspk_state;
static inline void generate_samples(PCSpkState *s)
{
unsigned int i;
if (s->pit_count) {
const uint32_t m = PCSPK_SAMPLE_RATE * s->pit_count;
const uint32_t n = ((uint64_t)PIT_FREQ << 32) / m;
/* multiple of wavelength for gapless looping */
s->samples = (PCSPK_BUF_LEN * PIT_FREQ / m * m / (PIT_FREQ >> 1) + 1) >> 1;
for (i = 0; i < s->samples; ++i)
s->sample_buf[i] = (64 & (n * i >> 25)) - 32;
} else {
s->samples = PCSPK_BUF_LEN;
for (i = 0; i < PCSPK_BUF_LEN; ++i)
s->sample_buf[i] = 128; /* silence */
}
}
static void pcspk_callback(void *opaque, int free)
{
PCSpkState *s = opaque;
unsigned int n;
if (pit_get_mode(s->pit, 2) != 3)
return;
n = pit_get_initial_count(s->pit, 2);
/* avoid frequencies that are not reproducible with sample rate */
if (n < PCSPK_MIN_COUNT)
n = 0;
if (s->pit_count != n) {
s->pit_count = n;
s->play_pos = 0;
generate_samples(s);
}
while (free > 0) {
n = audio_MIN(s->samples - s->play_pos, (unsigned int)free);
n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
if (!n)
break;
s->play_pos = (s->play_pos + n) % s->samples;
free -= n;
}
}
int pcspk_audio_init(AudioState *audio)
{
PCSpkState *s = &pcspk_state;
audsettings_t as = {PCSPK_SAMPLE_RATE, 1, AUD_FMT_U8, 0};
if (!audio) {
AUD_log(s_spk, "No audio state\n");
return -1;
}
AUD_register_card(audio, s_spk, &s->card);
s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
if (!s->voice) {
AUD_log(s_spk, "Could not open voice\n");
return -1;
}
return 0;
}
static uint32_t pcspk_ioport_read(void *opaque, uint32_t addr)
{
PCSpkState *s = opaque;
int out;
s->dummy_refresh_clock ^= (1 << 4);
out = pit_get_out(s->pit, 2, qemu_get_clock(vm_clock)) << 5;
return pit_get_gate(s->pit, 2) | (s->data_on << 1) | s->dummy_refresh_clock | out;
}
static void pcspk_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
PCSpkState *s = opaque;
const int gate = val & 1;
s->data_on = (val >> 1) & 1;
pit_set_gate(s->pit, 2, gate);
if (s->voice) {
if (gate) /* restart */
s->play_pos = 0;
AUD_set_active_out(s->voice, gate & s->data_on);
}
}
void pcspk_init(PITState *pit)
{
PCSpkState *s = &pcspk_state;
s->pit = pit;
register_ioport_read(0x61, 1, 1, pcspk_ioport_read, s);
register_ioport_write(0x61, 1, 1, pcspk_ioport_write, s);
}
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