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/i386/pc.h"
  28 #include "hw/isa/isa.h"
  29 #include "hw/audio/audio.h"
  30 #include "audio/audio.h"
  31 #include "qemu/timer.h"
  32 #include "hw/timer/i8254.h"
  33 #include "hw/audio/pcspk.h"
  34
  35 #define PCSPK_BUF_LEN 1792
  36 #define PCSPK_SAMPLE_RATE 32000
  37 #define PCSPK_MAX_FREQ (PCSPK_SAMPLE_RATE >> 1)
  38 #define PCSPK_MIN_COUNT ((PIT_FREQ + PCSPK_MAX_FREQ - 1) / PCSPK_MAX_FREQ)
  39
  40 #define PC_SPEAKER(obj) OBJECT_CHECK(PCSpkState, (obj), TYPE_PC_SPEAKER)
  41
  42 typedef struct {
  43     ISADevice parent_obj;
  44
  45     MemoryRegion ioport;
  46     uint32_t iobase;
  47     uint8_t sample_buf[PCSPK_BUF_LEN];
  48     QEMUSoundCard card;
  49     SWVoiceOut *voice;
  50     void *pit;
  51     unsigned int pit_count;
  52     unsigned int samples;
  53     unsigned int play_pos;
  54     int data_on;
  55     int dummy_refresh_clock;
  56 } PCSpkState;
  57
  58 static const char *s_spk = "pcspk";
  59 static PCSpkState *pcspk_state;
  60
  61 static inline void generate_samples(PCSpkState *s)
  62 {
  63     unsigned int i;
  64
  65     if (s->pit_count) {
  66         const uint32_t m = PCSPK_SAMPLE_RATE * s->pit_count;
  67         const uint32_t n = ((uint64_t)PIT_FREQ << 32) / m;
  68
  69         /* multiple of wavelength for gapless looping */
  70         s->samples = (PCSPK_BUF_LEN * PIT_FREQ / m * m / (PIT_FREQ >> 1) + 1) >> 1;
  71         for (i = 0; i < s->samples; ++i)
  72             s->sample_buf[i] = (64 & (n * i >> 25)) - 32;
  73     } else {
  74         s->samples = PCSPK_BUF_LEN;
  75         for (i = 0; i < PCSPK_BUF_LEN; ++i)
  76             s->sample_buf[i] = 128; /* silence */
  77     }
  78 }
  79
  80 static void pcspk_callback(void *opaque, int free)
  81 {
  82     PCSpkState *s = opaque;
  83     PITChannelInfo ch;
  84     unsigned int n;
  85
  86     pit_get_channel_info(s->pit, 2, &ch);
  87
  88     if (ch.mode != 3) {
  89         return;
  90     }
  91
  92     n = ch.initial_count;
  93     /* avoid frequencies that are not reproducible with sample rate */
  94     if (n < PCSPK_MIN_COUNT)
  95         n = 0;
  96
  97     if (s->pit_count != n) {
  98         s->pit_count = n;
  99         s->play_pos = 0;
 100         generate_samples(s);
 101     }
 102
 103     while (free > 0) {
 104         n = audio_MIN(s->samples - s->play_pos, (unsigned int)free);
 105         n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
 106         if (!n)
 107             break;
 108         s->play_pos = (s->play_pos + n) % s->samples;
 109         free -= n;
 110     }
 111 }
 112
 113 static int pcspk_audio_init(ISABus *bus)
 114 {
 115     PCSpkState *s = pcspk_state;
 116     struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUD_FMT_U8, 0};
 117
 118     AUD_register_card(s_spk, &s->card);
 119
 120     s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
 121     if (!s->voice) {
 122         AUD_log(s_spk, "Could not open voice\n");
 123         return -1;
 124     }
 125
 126     return 0;
 127 }
 128
 129 static uint64_t pcspk_io_read(void *opaque, hwaddr addr,
 130                               unsigned size)
 131 {
 132     PCSpkState *s = opaque;
 133     PITChannelInfo ch;
 134
 135     pit_get_channel_info(s->pit, 2, &ch);
 136
 137     s->dummy_refresh_clock ^= (1 << 4);
 138
 139     return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock |
 140        (ch.out << 5);
 141 }
 142
 143 static void pcspk_io_write(void *opaque, hwaddr addr, uint64_t val,
 144                            unsigned size)
 145 {
 146     PCSpkState *s = opaque;
 147     const int gate = val & 1;
 148
 149     s->data_on = (val >> 1) & 1;
 150     pit_set_gate(s->pit, 2, gate);
 151     if (s->voice) {
 152         if (gate) /* restart */
 153             s->play_pos = 0;
 154         AUD_set_active_out(s->voice, gate & s->data_on);
 155     }
 156 }
 157
 158 static const MemoryRegionOps pcspk_io_ops = {
 159     .read = pcspk_io_read,
 160     .write = pcspk_io_write,
 161     .impl = {
 162         .min_access_size = 1,
 163         .max_access_size = 1,
 164     },
 165 };
 166
 167 static void pcspk_initfn(Object *obj)
 168 {
 169     PCSpkState *s = PC_SPEAKER(obj);
 170
 171     memory_region_init_io(&s->ioport, OBJECT(s), &pcspk_io_ops, s, "pcspk", 1);
 172 }
 173
 174 static void pcspk_realizefn(DeviceState *dev, Error **errp)
 175 {
 176     ISADevice *isadev = ISA_DEVICE(dev);
 177     PCSpkState *s = PC_SPEAKER(dev);
 178
 179     isa_register_ioport(isadev, &s->ioport, s->iobase);
 180
 181     pcspk_state = s;
 182 }
 183
 184 static Property pcspk_properties[] = {
 185     DEFINE_PROP_UINT32("iobase", PCSpkState, iobase,  -1),
 186     DEFINE_PROP_PTR("pit", PCSpkState, pit),
 187     DEFINE_PROP_END_OF_LIST(),
 188 };
 189
 190 static void pcspk_class_initfn(ObjectClass *klass, void *data)
 191 {
 192     DeviceClass *dc = DEVICE_CLASS(klass);
 193
 194     dc->realize = pcspk_realizefn;
 195     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
 196     dc->props = pcspk_properties;
 197     /* Reason: pointer property "pit", realize sets global pcspk_state */
 198     dc->cannot_instantiate_with_device_add_yet = true;
 199 }
 200
 201 static const TypeInfo pcspk_info = {
 202     .name           = TYPE_PC_SPEAKER,
 203     .parent         = TYPE_ISA_DEVICE,
 204     .instance_size  = sizeof(PCSpkState),
 205     .instance_init  = pcspk_initfn,
 206     .class_init     = pcspk_class_initfn,
 207 };
 208
 209 static void pcspk_register(void)
 210 {
 211     type_register_static(&pcspk_info);
 212     isa_register_soundhw("pcspk", "PC speaker", pcspk_audio_init);
 213 }
 214 type_init(pcspk_register)