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 #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     int data_on;
  56     int dummy_refresh_clock;
  57 } PCSpkState;
  58
  59 static const char *s_spk = "pcspk";
  60 static PCSpkState *pcspk_state;
  61
  62 static inline void generate_samples(PCSpkState *s)
  63 {
  64     unsigned int i;
  65
  66     if (s->pit_count) {
  67         const uint32_t m = PCSPK_SAMPLE_RATE * s->pit_count;
  68         const uint32_t n = ((uint64_t)PIT_FREQ << 32) / m;
  69
  70         /* multiple of wavelength for gapless looping */
  71         s->samples = (PCSPK_BUF_LEN * PIT_FREQ / m * m / (PIT_FREQ >> 1) + 1) >> 1;
  72         for (i = 0; i < s->samples; ++i)
  73             s->sample_buf[i] = (64 & (n * i >> 25)) - 32;
  74     } else {
  75         s->samples = PCSPK_BUF_LEN;
  76         for (i = 0; i < PCSPK_BUF_LEN; ++i)
  77             s->sample_buf[i] = 128; /* silence */
  78     }
  79 }
  80
  81 static void pcspk_callback(void *opaque, int free)
  82 {
  83     PCSpkState *s = opaque;
  84     PITChannelInfo ch;
  85     unsigned int n;
  86
  87     pit_get_channel_info(s->pit, 2, &ch);
  88
  89     if (ch.mode != 3) {
  90         return;
  91     }
  92
  93     n = ch.initial_count;
  94     /* avoid frequencies that are not reproducible with sample rate */
  95     if (n < PCSPK_MIN_COUNT)
  96         n = 0;
  97
  98     if (s->pit_count != n) {
  99         s->pit_count = n;
 100         s->play_pos = 0;
 101         generate_samples(s);
 102     }
 103
 104     while (free > 0) {
 105         n = audio_MIN(s->samples - s->play_pos, (unsigned int)free);
 106         n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
 107         if (!n)
 108             break;
 109         s->play_pos = (s->play_pos + n) % s->samples;
 110         free -= n;
 111     }
 112 }
 113
 114 static int pcspk_audio_init(ISABus *bus)
 115 {
 116     PCSpkState *s = pcspk_state;
 117     struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUD_FMT_U8, 0};
 118
 119     AUD_register_card(s_spk, &s->card);
 120
 121     s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
 122     if (!s->voice) {
 123         AUD_log(s_spk, "Could not open voice\n");
 124         return -1;
 125     }
 126
 127     return 0;
 128 }
 129
 130 static uint64_t pcspk_io_read(void *opaque, hwaddr addr,
 131                               unsigned size)
 132 {
 133     PCSpkState *s = opaque;
 134     PITChannelInfo ch;
 135
 136     pit_get_channel_info(s->pit, 2, &ch);
 137
 138     s->dummy_refresh_clock ^= (1 << 4);
 139
 140     return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock |
 141        (ch.out << 5);
 142 }
 143
 144 static void pcspk_io_write(void *opaque, hwaddr addr, uint64_t val,
 145                            unsigned size)
 146 {
 147     PCSpkState *s = opaque;
 148     const int gate = val & 1;
 149
 150     s->data_on = (val >> 1) & 1;
 151     pit_set_gate(s->pit, 2, gate);
 152     if (s->voice) {
 153         if (gate) /* restart */
 154             s->play_pos = 0;
 155         AUD_set_active_out(s->voice, gate & s->data_on);
 156     }
 157 }
 158
 159 static const MemoryRegionOps pcspk_io_ops = {
 160     .read = pcspk_io_read,
 161     .write = pcspk_io_write,
 162     .impl = {
 163         .min_access_size = 1,
 164         .max_access_size = 1,
 165     },
 166 };
 167
 168 static void pcspk_initfn(Object *obj)
 169 {
 170     PCSpkState *s = PC_SPEAKER(obj);
 171
 172     memory_region_init_io(&s->ioport, OBJECT(s), &pcspk_io_ops, s, "pcspk", 1);
 173
 174     object_property_add_link(obj, "pit", TYPE_PIT_COMMON,
 175                              (Object **)&s->pit,
 176                              qdev_prop_allow_set_link_before_realize,
 177                              0, &error_abort);
 178 }
 179
 180 static void pcspk_realizefn(DeviceState *dev, Error **errp)
 181 {
 182     ISADevice *isadev = ISA_DEVICE(dev);
 183     PCSpkState *s = PC_SPEAKER(dev);
 184
 185     isa_register_ioport(isadev, &s->ioport, s->iobase);
 186
 187     pcspk_state = s;
 188 }
 189
 190 static Property pcspk_properties[] = {
 191     DEFINE_PROP_UINT32("iobase", PCSpkState, iobase,  -1),
 192     DEFINE_PROP_END_OF_LIST(),
 193 };
 194
 195 static void pcspk_class_initfn(ObjectClass *klass, void *data)
 196 {
 197     DeviceClass *dc = DEVICE_CLASS(klass);
 198
 199     dc->realize = pcspk_realizefn;
 200     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
 201     dc->props = pcspk_properties;
 202     /* Reason: realize sets global pcspk_state */
 203     dc->cannot_instantiate_with_device_add_yet = true;
 204 }
 205
 206 static const TypeInfo pcspk_info = {
 207     .name           = TYPE_PC_SPEAKER,
 208     .parent         = TYPE_ISA_DEVICE,
 209     .instance_size  = sizeof(PCSpkState),
 210     .instance_init  = pcspk_initfn,
 211     .class_init     = pcspk_class_initfn,
 212 };
 213
 214 static void pcspk_register(void)
 215 {
 216     type_register_static(&pcspk_info);
 217     isa_register_soundhw("pcspk", "PC speaker", pcspk_audio_init);
 218 }
 219 type_init(pcspk_register)