audio/noaudio.c

   1 /*
   2  * QEMU Timer based audio emulation
   3  *
   4  * Copyright (c) 2004-2005 Vassili Karpov (malc)
   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 "qemu/host-utils.h"
  27 #include "qemu/module.h"
  28 #include "audio.h"
  29 #include "qemu/timer.h"
  30
  31 #define AUDIO_CAP "noaudio"
  32 #include "audio_int.h"
  33
  34 typedef struct NoVoiceOut {
  35     HWVoiceOut hw;
  36     int64_t old_ticks;
  37 } NoVoiceOut;
  38
  39 typedef struct NoVoiceIn {
  40     HWVoiceIn hw;
  41     int64_t old_ticks;
  42 } NoVoiceIn;
  43
  44 static size_t no_write(HWVoiceOut *hw, void *buf, size_t len)
  45 {
  46     NoVoiceOut *no = (NoVoiceOut *) hw;
  47     int64_t now;
  48     int64_t ticks;
  49     int64_t bytes;
  50
  51     now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  52     ticks = now - no->old_ticks;
  53     bytes = muldiv64(ticks, hw->info.bytes_per_second, NANOSECONDS_PER_SECOND);
  54
  55     no->old_ticks = now;
  56     return MIN(len, bytes);
  57 }
  58
  59 static int no_init_out(HWVoiceOut *hw, struct audsettings *as, void *drv_opaque)
  60 {
  61     audio_pcm_init_info (&hw->info, as);
  62     hw->samples = 1024;
  63     return 0;
  64 }
  65
  66 static void no_fini_out (HWVoiceOut *hw)
  67 {
  68     (void) hw;
  69 }
  70
  71 static int no_ctl_out (HWVoiceOut *hw, int cmd, ...)
  72 {
  73     (void) hw;
  74     (void) cmd;
  75     return 0;
  76 }
  77
  78 static int no_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
  79 {
  80     audio_pcm_init_info (&hw->info, as);
  81     hw->samples = 1024;
  82     return 0;
  83 }
  84
  85 static void no_fini_in (HWVoiceIn *hw)
  86 {
  87     (void) hw;
  88 }
  89
  90 static size_t no_read(HWVoiceIn *hw, void *buf, size_t size)
  91 {
  92     size_t to_clear;
  93     NoVoiceIn *no = (NoVoiceIn *) hw;
  94
  95     int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  96     int64_t ticks = now - no->old_ticks;
  97     int64_t bytes =
  98         muldiv64(ticks, hw->info.bytes_per_second, NANOSECONDS_PER_SECOND);
  99
 100     no->old_ticks = now;
 101     to_clear = MIN(bytes, size);
 102
 103     audio_pcm_info_clear_buf(&hw->info, buf, to_clear >> hw->info.shift);
 104     return to_clear;
 105 }
 106
 107 static int no_ctl_in (HWVoiceIn *hw, int cmd, ...)
 108 {
 109     (void) hw;
 110     (void) cmd;
 111     return 0;
 112 }
 113
 114 static void *no_audio_init(Audiodev *dev)
 115 {
 116     return &no_audio_init;
 117 }
 118
 119 static void no_audio_fini (void *opaque)
 120 {
 121     (void) opaque;
 122 }
 123
 124 static struct audio_pcm_ops no_pcm_ops = {
 125     .init_out = no_init_out,
 126     .fini_out = no_fini_out,
 127     .write    = no_write,
 128     .ctl_out  = no_ctl_out,
 129
 130     .init_in  = no_init_in,
 131     .fini_in  = no_fini_in,
 132     .read     = no_read,
 133     .ctl_in   = no_ctl_in
 134 };
 135
 136 static struct audio_driver no_audio_driver = {
 137     .name           = "none",
 138     .descr          = "Timer based audio emulation",
 139     .init           = no_audio_init,
 140     .fini           = no_audio_fini,
 141     .pcm_ops        = &no_pcm_ops,
 142     .can_be_default = 1,
 143     .max_voices_out = INT_MAX,
 144     .max_voices_in  = INT_MAX,
 145     .voice_size_out = sizeof (NoVoiceOut),
 146     .voice_size_in  = sizeof (NoVoiceIn)
 147 };
 148
 149 static void register_audio_none(void)
 150 {
 151     audio_driver_register(&no_audio_driver);
 152 }
 153 type_init(register_audio_none);