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 "hw/hw.h"
  26 #include "hw/i386/pc.h"
  27 #include "hw/isa/isa.h"
  28 #include "hw/audio/audio.h"
  29 #include "audio/audio.h"
  30 #include "qemu/timer.h"
  31 #include "hw/timer/i8254.h"
  32 #include "hw/audio/pcspk.h"
  33
  34 #define PCSPK_BUF_LEN 1792
  35 #define PCSPK_SAMPLE_RATE 32000
  36 #define PCSPK_MAX_FREQ (PCSPK_SAMPLE_RATE >> 1)
  37 #define PCSPK_MIN_COUNT ((PIT_FREQ + PCSPK_MAX_FREQ - 1) / PCSPK_MAX_FREQ)
  38
  39 #define PC_SPEAKER(obj) OBJECT_CHECK(PCSpkState, (obj), TYPE_PC_SPEAKER)
  40
  41 typedef struct {
  42     ISADevice parent_obj;
  43
  44     MemoryRegion ioport;
  45     uint32_t iobase;
  46     uint8_t sample_buf[PCSPK_BUF_LEN];
  47     QEMUSoundCard card;
  48     SWVoiceOut *voice;
  49     void *pit;
  50     unsigned int pit_count;
  51     unsigned int samples;
  52     unsigned int play_pos;
  53     int data_on;
  54     int dummy_refresh_clock;
  55 } PCSpkState;
  56
  57 static const char *s_spk = "pcspk";
  58 static PCSpkState *pcspk_state;
  59
  60 static inline void generate_samples(PCSpkState *s)
  61 {
  62     unsigned int i;
  63
  64     if (s->pit_count) {
  65         const uint32_t m = PCSPK_SAMPLE_RATE * s->pit_count;
  66         const uint32_t n = ((uint64_t)PIT_FREQ << 32) / m;
  67
  68         /* multiple of wavelength for gapless looping */
  69         s->samples = (PCSPK_BUF_LEN * PIT_FREQ / m * m / (PIT_FREQ >> 1) + 1) >> 1;
  70         for (i = 0; i < s->samples; ++i)
  71             s->sample_buf[i] = (64 & (n * i >> 25)) - 32;
  72     } else {
  73         s->samples = PCSPK_BUF_LEN;
  74         for (i = 0; i < PCSPK_BUF_LEN; ++i)
  75             s->sample_buf[i] = 128; /* silence */
  76     }
  77 }
  78
  79 static void pcspk_callback(void *opaque, int free)
  80 {
  81     PCSpkState *s = opaque;
  82     PITChannelInfo ch;
  83     unsigned int n;
  84
  85     pit_get_channel_info(s->pit, 2, &ch);
  86
  87     if (ch.mode != 3) {
  88         return;
  89     }
  90
  91     n = ch.initial_count;
  92     /* avoid frequencies that are not reproducible with sample rate */
  93     if (n < PCSPK_MIN_COUNT)
  94         n = 0;
  95
  96     if (s->pit_count != n) {
  97         s->pit_count = n;
  98         s->play_pos = 0;
  99         generate_samples(s);
 100     }
 101
 102     while (free > 0) {
 103         n = audio_MIN(s->samples - s->play_pos, (unsigned int)free);
 104         n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
 105         if (!n)
 106             break;
 107         s->play_pos = (s->play_pos + n) % s->samples;
 108         free -= n;
 109     }
 110 }
 111
 112 static int pcspk_audio_init(ISABus *bus)
 113 {
 114     PCSpkState *s = pcspk_state;
 115     struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUD_FMT_U8, 0};
 116
 117     AUD_register_card(s_spk, &s->card);
 118
 119     s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
 120     if (!s->voice) {
 121         AUD_log(s_spk, "Could not open voice\n");
 122         return -1;
 123     }
 124
 125     return 0;
 126 }
 127
 128 static uint64_t pcspk_io_read(void *opaque, hwaddr addr,
 129                               unsigned size)
 130 {
 131     PCSpkState *s = opaque;
 132     PITChannelInfo ch;
 133
 134     pit_get_channel_info(s->pit, 2, &ch);
 135
 136     s->dummy_refresh_clock ^= (1 << 4);
 137
 138     return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock |
 139        (ch.out << 5);
 140 }
 141
 142 static void pcspk_io_write(void *opaque, hwaddr addr, uint64_t val,
 143                            unsigned size)
 144 {
 145     PCSpkState *s = opaque;
 146     const int gate = val & 1;
 147
 148     s->data_on = (val >> 1) & 1;
 149     pit_set_gate(s->pit, 2, gate);
 150     if (s->voice) {
 151         if (gate) /* restart */
 152             s->play_pos = 0;
 153         AUD_set_active_out(s->voice, gate & s->data_on);
 154     }
 155 }
 156
 157 static const MemoryRegionOps pcspk_io_ops = {
 158     .read = pcspk_io_read,
 159     .write = pcspk_io_write,
 160     .impl = {
 161         .min_access_size = 1,
 162         .max_access_size = 1,
 163     },
 164 };
 165
 166 static int pcspk_initfn(ISADevice *dev)
 167 {
 168     PCSpkState *s = PC_SPEAKER(dev);
 169
 170     memory_region_init_io(&s->ioport, &pcspk_io_ops, s, "elcr", 1);
 171     isa_register_ioport(dev, &s->ioport, s->iobase);
 172
 173     pcspk_state = s;
 174
 175     return 0;
 176 }
 177
 178 static Property pcspk_properties[] = {
 179     DEFINE_PROP_HEX32("iobase", PCSpkState, iobase,  -1),
 180     DEFINE_PROP_PTR("pit", PCSpkState, pit),
 181     DEFINE_PROP_END_OF_LIST(),
 182 };
 183
 184 static void pcspk_class_initfn(ObjectClass *klass, void *data)
 185 {
 186     DeviceClass *dc = DEVICE_CLASS(klass);
 187     ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
 188
 189     ic->init = pcspk_initfn;
 190     dc->no_user = 1;
 191     dc->props = pcspk_properties;
 192 }
 193
 194 static const TypeInfo pcspk_info = {
 195     .name           = TYPE_PC_SPEAKER,
 196     .parent         = TYPE_ISA_DEVICE,
 197     .instance_size  = sizeof(PCSpkState),
 198     .class_init     = pcspk_class_initfn,
 199 };
 200
 201 static void pcspk_register(void)
 202 {
 203     type_register_static(&pcspk_info);
 204     isa_register_soundhw("pcspk", "PC speaker", pcspk_audio_init);
 205 }
 206 type_init(pcspk_register)