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