hw/audio/pcspk.c

   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/hw.h"
  27 #include "hw/isa/isa.h"
  28 #include "hw/audio/soundhw.h"
  29 #include "audio/audio.h"
  30 #include "qemu/module.h"
  31 #include "qemu/timer.h"
  32 #include "hw/timer/i8254.h"
  33 #include "hw/audio/pcspk.h"
  34 #include "qapi/error.h"
  35
  36 #define PCSPK_BUF_LEN 1792
  37 #define PCSPK_SAMPLE_RATE 32000
  38 #define PCSPK_MAX_FREQ (PCSPK_SAMPLE_RATE >> 1)
  39 #define PCSPK_MIN_COUNT DIV_ROUND_UP(PIT_FREQ, PCSPK_MAX_FREQ)
  40
  41 #define PC_SPEAKER(obj) OBJECT_CHECK(PCSpkState, (obj), TYPE_PC_SPEAKER)
  42
  43 typedef struct {
  44     ISADevice parent_obj;
  45
  46     MemoryRegion ioport;
  47     uint32_t iobase;
  48     uint8_t sample_buf[PCSPK_BUF_LEN];
  49     QEMUSoundCard card;
  50     SWVoiceOut *voice;
  51     void *pit;
  52     unsigned int pit_count;
  53     unsigned int samples;
  54     unsigned int play_pos;
  55     uint8_t data_on;
  56     uint8_t dummy_refresh_clock;
  57     bool migrate;
  58 } PCSpkState;
  59
  60 static const char *s_spk = "pcspk";
  61 static PCSpkState *pcspk_state;
  62
  63 static inline void generate_samples(PCSpkState *s)
  64 {
  65     unsigned int i;
  66
  67     if (s->pit_count) {
  68         const uint32_t m = PCSPK_SAMPLE_RATE * s->pit_count;
  69         const uint32_t n = ((uint64_t)PIT_FREQ << 32) / m;
  70
  71         /* multiple of wavelength for gapless looping */
  72         s->samples = (QEMU_ALIGN_DOWN(PCSPK_BUF_LEN * PIT_FREQ, m) / (PIT_FREQ >> 1) + 1) >> 1;
  73         for (i = 0; i < s->samples; ++i)
  74             s->sample_buf[i] = (64 & (n * i >> 25)) - 32;
  75     } else {
  76         s->samples = PCSPK_BUF_LEN;
  77         for (i = 0; i < PCSPK_BUF_LEN; ++i)
  78             s->sample_buf[i] = 128; /* silence */
  79     }
  80 }
  81
  82 static void pcspk_callback(void *opaque, int free)
  83 {
  84     PCSpkState *s = opaque;
  85     PITChannelInfo ch;
  86     unsigned int n;
  87
  88     pit_get_channel_info(s->pit, 2, &ch);
  89
  90     if (ch.mode != 3) {
  91         return;
  92     }
  93
  94     n = ch.initial_count;
  95     /* avoid frequencies that are not reproducible with sample rate */
  96     if (n < PCSPK_MIN_COUNT)
  97         n = 0;
  98
  99     if (s->pit_count != n) {
 100         s->pit_count = n;
 101         s->play_pos = 0;
 102         generate_samples(s);
 103     }
 104
 105     while (free > 0) {
 106         n = audio_MIN(s->samples - s->play_pos, (unsigned int)free);
 107         n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
 108         if (!n)
 109             break;
 110         s->play_pos = (s->play_pos + n) % s->samples;
 111         free -= n;
 112     }
 113 }
 114
 115 static int pcspk_audio_init(ISABus *bus)
 116 {
 117     PCSpkState *s = pcspk_state;
 118     struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUDIO_FORMAT_U8, 0};
 119
 120     AUD_register_card(s_spk, &s->card);
 121
 122     s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
 123     if (!s->voice) {
 124         AUD_log(s_spk, "Could not open voice\n");
 125         return -1;
 126     }
 127
 128     return 0;
 129 }
 130
 131 static uint64_t pcspk_io_read(void *opaque, hwaddr addr,
 132                               unsigned size)
 133 {
 134     PCSpkState *s = opaque;
 135     PITChannelInfo ch;
 136
 137     pit_get_channel_info(s->pit, 2, &ch);
 138
 139     s->dummy_refresh_clock ^= (1 << 4);
 140
 141     return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock |
 142        (ch.out << 5);
 143 }
 144
 145 static void pcspk_io_write(void *opaque, hwaddr addr, uint64_t val,
 146                            unsigned size)
 147 {
 148     PCSpkState *s = opaque;
 149     const int gate = val & 1;
 150
 151     s->data_on = (val >> 1) & 1;
 152     pit_set_gate(s->pit, 2, gate);
 153     if (s->voice) {
 154         if (gate) /* restart */
 155             s->play_pos = 0;
 156         AUD_set_active_out(s->voice, gate & s->data_on);
 157     }
 158 }
 159
 160 static const MemoryRegionOps pcspk_io_ops = {
 161     .read = pcspk_io_read,
 162     .write = pcspk_io_write,
 163     .impl = {
 164         .min_access_size = 1,
 165         .max_access_size = 1,
 166     },
 167 };
 168
 169 static void pcspk_initfn(Object *obj)
 170 {
 171     PCSpkState *s = PC_SPEAKER(obj);
 172
 173     memory_region_init_io(&s->ioport, OBJECT(s), &pcspk_io_ops, s, "pcspk", 1);
 174
 175     object_property_add_link(obj, "pit", TYPE_PIT_COMMON,
 176                              (Object **)&s->pit,
 177                              qdev_prop_allow_set_link_before_realize,
 178                              0, &error_abort);
 179 }
 180
 181 static void pcspk_realizefn(DeviceState *dev, Error **errp)
 182 {
 183     ISADevice *isadev = ISA_DEVICE(dev);
 184     PCSpkState *s = PC_SPEAKER(dev);
 185
 186     isa_register_ioport(isadev, &s->ioport, s->iobase);
 187
 188     pcspk_state = s;
 189 }
 190
 191 static bool migrate_needed(void *opaque)
 192 {
 193     PCSpkState *s = opaque;
 194
 195     return s->migrate;
 196 }
 197
 198 static const VMStateDescription vmstate_spk = {
 199     .name = "pcspk",
 200     .version_id = 1,
 201     .minimum_version_id = 1,
 202     .minimum_version_id_old = 1,
 203     .needed = migrate_needed,
 204     .fields      = (VMStateField[]) {
 205         VMSTATE_UINT8(data_on, PCSpkState),
 206         VMSTATE_UINT8(dummy_refresh_clock, PCSpkState),
 207         VMSTATE_END_OF_LIST()
 208     }
 209 };
 210
 211 static Property pcspk_properties[] = {
 212     DEFINE_PROP_UINT32("iobase", PCSpkState, iobase,  -1),
 213     DEFINE_PROP_BOOL("migrate", PCSpkState, migrate,  true),
 214     DEFINE_PROP_END_OF_LIST(),
 215 };
 216
 217 static void pcspk_class_initfn(ObjectClass *klass, void *data)
 218 {
 219     DeviceClass *dc = DEVICE_CLASS(klass);
 220
 221     dc->realize = pcspk_realizefn;
 222     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
 223     dc->vmsd = &vmstate_spk;
 224     dc->props = pcspk_properties;
 225     /* Reason: realize sets global pcspk_state */
 226     /* Reason: pit object link */
 227     dc->user_creatable = false;
 228 }
 229
 230 static const TypeInfo pcspk_info = {
 231     .name           = TYPE_PC_SPEAKER,
 232     .parent         = TYPE_ISA_DEVICE,
 233     .instance_size  = sizeof(PCSpkState),
 234     .instance_init  = pcspk_initfn,
 235     .class_init     = pcspk_class_initfn,
 236 };
 237
 238 static void pcspk_register(void)
 239 {
 240     type_register_static(&pcspk_info);
 241     isa_register_soundhw("pcspk", "PC speaker", pcspk_audio_init);
 242 }
 243 type_init(pcspk_register)