qemu/hw/audio/pcspk.c
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   1/*
   2 * QEMU PC speaker emulation
   3 *
   4 * Copyright (c) 2006 Joachim Henke
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24
  25#include "qemu/osdep.h"
  26#include "hw/isa/isa.h"
  27#include "hw/audio/soundhw.h"
  28#include "audio/audio.h"
  29#include "qemu/module.h"
  30#include "qemu/timer.h"
  31#include "qemu/error-report.h"
  32#include "hw/timer/i8254.h"
  33#include "migration/vmstate.h"
  34#include "hw/audio/pcspk.h"
  35#include "qapi/error.h"
  36#include "qom/object.h"
  37
  38#define PCSPK_BUF_LEN 1792
  39#define PCSPK_SAMPLE_RATE 32000
  40#define PCSPK_MAX_FREQ (PCSPK_SAMPLE_RATE >> 1)
  41#define PCSPK_MIN_COUNT DIV_ROUND_UP(PIT_FREQ, PCSPK_MAX_FREQ)
  42
  43OBJECT_DECLARE_SIMPLE_TYPE(PCSpkState, PC_SPEAKER)
  44
  45struct PCSpkState {
  46    ISADevice parent_obj;
  47
  48    MemoryRegion ioport;
  49    uint32_t iobase;
  50    uint8_t sample_buf[PCSPK_BUF_LEN];
  51    QEMUSoundCard card;
  52    SWVoiceOut *voice;
  53    void *pit;
  54    unsigned int pit_count;
  55    unsigned int samples;
  56    unsigned int play_pos;
  57    uint8_t data_on;
  58    uint8_t dummy_refresh_clock;
  59    bool migrate;
  60};
  61
  62static const char *s_spk = "pcspk";
  63static PCSpkState *pcspk_state;
  64
  65static inline void generate_samples(PCSpkState *s)
  66{
  67    unsigned int i;
  68
  69    if (s->pit_count) {
  70        const uint32_t m = PCSPK_SAMPLE_RATE * s->pit_count;
  71        const uint32_t n = ((uint64_t)PIT_FREQ << 32) / m;
  72
  73        /* multiple of wavelength for gapless looping */
  74        s->samples = (QEMU_ALIGN_DOWN(PCSPK_BUF_LEN * PIT_FREQ, m) / (PIT_FREQ >> 1) + 1) >> 1;
  75        for (i = 0; i < s->samples; ++i)
  76            s->sample_buf[i] = (64 & (n * i >> 25)) - 32;
  77    } else {
  78        s->samples = PCSPK_BUF_LEN;
  79        for (i = 0; i < PCSPK_BUF_LEN; ++i)
  80            s->sample_buf[i] = 128; /* silence */
  81    }
  82}
  83
  84static void pcspk_callback(void *opaque, int free)
  85{
  86    PCSpkState *s = opaque;
  87    PITChannelInfo ch;
  88    unsigned int n;
  89
  90    pit_get_channel_info(s->pit, 2, &ch);
  91
  92    if (ch.mode != 3) {
  93        return;
  94    }
  95
  96    n = ch.initial_count;
  97    /* avoid frequencies that are not reproducible with sample rate */
  98    if (n < PCSPK_MIN_COUNT)
  99        n = 0;
 100
 101    if (s->pit_count != n) {
 102        s->pit_count = n;
 103        s->play_pos = 0;
 104        generate_samples(s);
 105    }
 106
 107    while (free > 0) {
 108        n = MIN(s->samples - s->play_pos, (unsigned int)free);
 109        n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
 110        if (!n)
 111            break;
 112        s->play_pos = (s->play_pos + n) % s->samples;
 113        free -= n;
 114    }
 115}
 116
 117static int pcspk_audio_init(PCSpkState *s)
 118{
 119    struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUDIO_FORMAT_U8, 0};
 120
 121    if (s->voice) {
 122        /* already initialized */
 123        return 0;
 124    }
 125
 126    AUD_register_card(s_spk, &s->card);
 127
 128    s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
 129    if (!s->voice) {
 130        AUD_log(s_spk, "Could not open voice\n");
 131        return -1;
 132    }
 133
 134    return 0;
 135}
 136
 137static uint64_t pcspk_io_read(void *opaque, hwaddr addr,
 138                              unsigned size)
 139{
 140    PCSpkState *s = opaque;
 141    PITChannelInfo ch;
 142
 143    pit_get_channel_info(s->pit, 2, &ch);
 144
 145    s->dummy_refresh_clock ^= (1 << 4);
 146
 147    return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock |
 148       (ch.out << 5);
 149}
 150
 151static void pcspk_io_write(void *opaque, hwaddr addr, uint64_t val,
 152                           unsigned size)
 153{
 154    PCSpkState *s = opaque;
 155    const int gate = val & 1;
 156
 157    s->data_on = (val >> 1) & 1;
 158    pit_set_gate(s->pit, 2, gate);
 159    if (s->voice) {
 160        if (gate) /* restart */
 161            s->play_pos = 0;
 162        AUD_set_active_out(s->voice, gate & s->data_on);
 163    }
 164}
 165
 166static const MemoryRegionOps pcspk_io_ops = {
 167    .read = pcspk_io_read,
 168    .write = pcspk_io_write,
 169    .impl = {
 170        .min_access_size = 1,
 171        .max_access_size = 1,
 172    },
 173};
 174
 175static void pcspk_initfn(Object *obj)
 176{
 177    PCSpkState *s = PC_SPEAKER(obj);
 178
 179    memory_region_init_io(&s->ioport, OBJECT(s), &pcspk_io_ops, s, "pcspk", 1);
 180
 181    object_property_add_link(obj, "pit", TYPE_PIT_COMMON,
 182                             (Object **)&s->pit,
 183                             qdev_prop_allow_set_link_before_realize,
 184                             0);
 185}
 186
 187static void pcspk_realizefn(DeviceState *dev, Error **errp)
 188{
 189    ISADevice *isadev = ISA_DEVICE(dev);
 190    PCSpkState *s = PC_SPEAKER(dev);
 191
 192    isa_register_ioport(isadev, &s->ioport, s->iobase);
 193
 194    if (s->card.state) {
 195        pcspk_audio_init(s);
 196    }
 197
 198    pcspk_state = s;
 199}
 200
 201static bool migrate_needed(void *opaque)
 202{
 203    PCSpkState *s = opaque;
 204
 205    return s->migrate;
 206}
 207
 208static const VMStateDescription vmstate_spk = {
 209    .name = "pcspk",
 210    .version_id = 1,
 211    .minimum_version_id = 1,
 212    .needed = migrate_needed,
 213    .fields      = (VMStateField[]) {
 214        VMSTATE_UINT8(data_on, PCSpkState),
 215        VMSTATE_UINT8(dummy_refresh_clock, PCSpkState),
 216        VMSTATE_END_OF_LIST()
 217    }
 218};
 219
 220static Property pcspk_properties[] = {
 221    DEFINE_AUDIO_PROPERTIES(PCSpkState, card),
 222    DEFINE_PROP_UINT32("iobase", PCSpkState, iobase,  0x61),
 223    DEFINE_PROP_BOOL("migrate", PCSpkState, migrate,  true),
 224    DEFINE_PROP_END_OF_LIST(),
 225};
 226
 227static void pcspk_class_initfn(ObjectClass *klass, void *data)
 228{
 229    DeviceClass *dc = DEVICE_CLASS(klass);
 230
 231    dc->realize = pcspk_realizefn;
 232    set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
 233    dc->vmsd = &vmstate_spk;
 234    device_class_set_props(dc, pcspk_properties);
 235    /* Reason: realize sets global pcspk_state */
 236    /* Reason: pit object link */
 237    dc->user_creatable = false;
 238}
 239
 240static const TypeInfo pcspk_info = {
 241    .name           = TYPE_PC_SPEAKER,
 242    .parent         = TYPE_ISA_DEVICE,
 243    .instance_size  = sizeof(PCSpkState),
 244    .instance_init  = pcspk_initfn,
 245    .class_init     = pcspk_class_initfn,
 246};
 247
 248static void pcspk_register(void)
 249{
 250    type_register_static(&pcspk_info);
 251}
 252type_init(pcspk_register)
 253