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.h"
  26 #include "pc.h"
  27 #include "isa.h"
  28 #include "audio/audio.h"
  29 #include "qemu-timer.h"
  30 #include "i8254.h"
  31 #include "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     unsigned int n;
  79
  80     if (pit_get_mode(s->pit, 2) != 3)
  81         return;
  82
  83     n = pit_get_initial_count(s->pit, 2);
  84     /* avoid frequencies that are not reproducible with sample rate */
  85     if (n < PCSPK_MIN_COUNT)
  86         n = 0;
  87
  88     if (s->pit_count != n) {
  89         s->pit_count = n;
  90         s->play_pos = 0;
  91         generate_samples(s);
  92     }
  93
  94     while (free > 0) {
  95         n = audio_MIN(s->samples - s->play_pos, (unsigned int)free);
  96         n = AUD_write(s->voice, &s->sample_buf[s->play_pos], n);
  97         if (!n)
  98             break;
  99         s->play_pos = (s->play_pos + n) % s->samples;
 100         free -= n;
 101     }
 102 }
 103
 104 int pcspk_audio_init(ISABus *bus)
 105 {
 106     PCSpkState *s = pcspk_state;
 107     struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUD_FMT_U8, 0};
 108
 109     AUD_register_card(s_spk, &s->card);
 110
 111     s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
 112     if (!s->voice) {
 113         AUD_log(s_spk, "Could not open voice\n");
 114         return -1;
 115     }
 116
 117     return 0;
 118 }
 119
 120 static uint64_t pcspk_io_read(void *opaque, target_phys_addr_t addr,
 121                               unsigned size)
 122 {
 123     PCSpkState *s = opaque;
 124     int out;
 125
 126     s->dummy_refresh_clock ^= (1 << 4);
 127     out = pit_get_out(s->pit, 2, qemu_get_clock_ns(vm_clock)) << 5;
 128
 129     return pit_get_gate(s->pit, 2) | (s->data_on << 1) | s->dummy_refresh_clock | out;
 130 }
 131
 132 static void pcspk_io_write(void *opaque, target_phys_addr_t addr, uint64_t val,
 133                            unsigned size)
 134 {
 135     PCSpkState *s = opaque;
 136     const int gate = val & 1;
 137
 138     s->data_on = (val >> 1) & 1;
 139     pit_set_gate(s->pit, 2, gate);
 140     if (s->voice) {
 141         if (gate) /* restart */
 142             s->play_pos = 0;
 143         AUD_set_active_out(s->voice, gate & s->data_on);
 144     }
 145 }
 146
 147 static const MemoryRegionOps pcspk_io_ops = {
 148     .read = pcspk_io_read,
 149     .write = pcspk_io_write,
 150     .impl = {
 151         .min_access_size = 1,
 152         .max_access_size = 1,
 153     },
 154 };
 155
 156 static int pcspk_initfn(ISADevice *dev)
 157 {
 158     PCSpkState *s = DO_UPCAST(PCSpkState, dev, dev);
 159
 160     memory_region_init_io(&s->ioport, &pcspk_io_ops, s, "elcr", 1);
 161     isa_register_ioport(dev, &s->ioport, s->iobase);
 162
 163     pcspk_state = s;
 164
 165     return 0;
 166 }
 167
 168 static Property pcspk_properties[] = {
 169     DEFINE_PROP_HEX32("iobase", PCSpkState, iobase,  -1),
 170     DEFINE_PROP_PTR("pit", PCSpkState, pit),
 171     DEFINE_PROP_END_OF_LIST(),
 172 };
 173
 174 static void pcspk_class_initfn(ObjectClass *klass, void *data)
 175 {
 176     DeviceClass *dc = DEVICE_CLASS(klass);
 177     ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
 178
 179     ic->init = pcspk_initfn;
 180     dc->no_user = 1;
 181     dc->props = pcspk_properties;
 182 }
 183
 184 static TypeInfo pcspk_info = {
 185     .name           = "isa-pcspk",
 186     .parent         = TYPE_ISA_DEVICE,
 187     .instance_size  = sizeof(PCSpkState),
 188     .class_init     = pcspk_class_initfn,
 189 };
 190
 191 static void pcspk_register(void)
 192 {
 193     type_register_static(&pcspk_info);
 194 }
 195 type_init(pcspk_register)