diff options
Diffstat (limited to 'hw/audio/pcspk.c')
| -rw-r--r-- | hw/audio/pcspk.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/hw/audio/pcspk.c b/hw/audio/pcspk.c new file mode 100644 index 0000000000..34e0df7485 --- /dev/null +++ b/hw/audio/pcspk.c @@ -0,0 +1,201 @@ +/* + * 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 "hw/hw.h" +#include "hw/i386/pc.h" +#include "hw/isa/isa.h" +#include "audio/audio.h" +#include "qemu/timer.h" +#include "hw/timer/i8254.h" +#include "hw/audio/pcspk.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 { + ISADevice dev; + MemoryRegion ioport; + uint32_t iobase; + uint8_t sample_buf[PCSPK_BUF_LEN]; + QEMUSoundCard card; + SWVoiceOut *voice; + void *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; + PITChannelInfo ch; + unsigned int n; + + pit_get_channel_info(s->pit, 2, &ch); + + if (ch.mode != 3) { + return; + } + + n = ch.initial_count; + /* 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(ISABus *bus) +{ + PCSpkState *s = pcspk_state; + struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUD_FMT_U8, 0}; + + AUD_register_card(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 uint64_t pcspk_io_read(void *opaque, hwaddr addr, + unsigned size) +{ + PCSpkState *s = opaque; + PITChannelInfo ch; + + pit_get_channel_info(s->pit, 2, &ch); + + s->dummy_refresh_clock ^= (1 << 4); + + return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock | + (ch.out << 5); +} + +static void pcspk_io_write(void *opaque, hwaddr addr, uint64_t val, + unsigned size) +{ + 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); + } +} + +static const MemoryRegionOps pcspk_io_ops = { + .read = pcspk_io_read, + .write = pcspk_io_write, + .impl = { + .min_access_size = 1, + .max_access_size = 1, + }, +}; + +static int pcspk_initfn(ISADevice *dev) +{ + PCSpkState *s = DO_UPCAST(PCSpkState, dev, dev); + + memory_region_init_io(&s->ioport, &pcspk_io_ops, s, "elcr", 1); + isa_register_ioport(dev, &s->ioport, s->iobase); + + pcspk_state = s; + + return 0; +} + +static Property pcspk_properties[] = { + DEFINE_PROP_HEX32("iobase", PCSpkState, iobase, -1), + DEFINE_PROP_PTR("pit", PCSpkState, pit), + DEFINE_PROP_END_OF_LIST(), +}; + +static void pcspk_class_initfn(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + ISADeviceClass *ic = ISA_DEVICE_CLASS(klass); + + ic->init = pcspk_initfn; + dc->no_user = 1; + dc->props = pcspk_properties; +} + +static const TypeInfo pcspk_info = { + .name = "isa-pcspk", + .parent = TYPE_ISA_DEVICE, + .instance_size = sizeof(PCSpkState), + .class_init = pcspk_class_initfn, +}; + +static void pcspk_register(void) +{ + type_register_static(&pcspk_info); +} +type_init(pcspk_register) |