xref: /openbmc/qemu/audio/noaudio.c (revision a27bd6c7)
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 int no_run_out (HWVoiceOut *hw, int live)
45 {
46     NoVoiceOut *no = (NoVoiceOut *) hw;
47     int decr, samples;
48     int64_t now;
49     int64_t ticks;
50     int64_t bytes;
51 
52     now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
53     ticks = now - no->old_ticks;
54     bytes = muldiv64(ticks, hw->info.bytes_per_second, NANOSECONDS_PER_SECOND);
55     bytes = audio_MIN(bytes, INT_MAX);
56     samples = bytes >> hw->info.shift;
57 
58     no->old_ticks = now;
59     decr = audio_MIN (live, samples);
60     hw->rpos = (hw->rpos + decr) % hw->samples;
61     return decr;
62 }
63 
64 static int no_write (SWVoiceOut *sw, void *buf, int len)
65 {
66     return audio_pcm_sw_write(sw, buf, len);
67 }
68 
69 static int no_init_out(HWVoiceOut *hw, struct audsettings *as, void *drv_opaque)
70 {
71     audio_pcm_init_info (&hw->info, as);
72     hw->samples = 1024;
73     return 0;
74 }
75 
76 static void no_fini_out (HWVoiceOut *hw)
77 {
78     (void) hw;
79 }
80 
81 static int no_ctl_out (HWVoiceOut *hw, int cmd, ...)
82 {
83     (void) hw;
84     (void) cmd;
85     return 0;
86 }
87 
88 static int no_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
89 {
90     audio_pcm_init_info (&hw->info, as);
91     hw->samples = 1024;
92     return 0;
93 }
94 
95 static void no_fini_in (HWVoiceIn *hw)
96 {
97     (void) hw;
98 }
99 
100 static int no_run_in (HWVoiceIn *hw)
101 {
102     NoVoiceIn *no = (NoVoiceIn *) hw;
103     int live = audio_pcm_hw_get_live_in (hw);
104     int dead = hw->samples - live;
105     int samples = 0;
106 
107     if (dead) {
108         int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
109         int64_t ticks = now - no->old_ticks;
110         int64_t bytes =
111             muldiv64(ticks, hw->info.bytes_per_second, NANOSECONDS_PER_SECOND);
112 
113         no->old_ticks = now;
114         bytes = audio_MIN (bytes, INT_MAX);
115         samples = bytes >> hw->info.shift;
116         samples = audio_MIN (samples, dead);
117     }
118     return samples;
119 }
120 
121 static int no_read (SWVoiceIn *sw, void *buf, int size)
122 {
123     /* use custom code here instead of audio_pcm_sw_read() to avoid
124      * useless resampling/mixing */
125     int samples = size >> sw->info.shift;
126     int total = sw->hw->total_samples_captured - sw->total_hw_samples_acquired;
127     int to_clear = audio_MIN (samples, total);
128     sw->total_hw_samples_acquired += total;
129     audio_pcm_info_clear_buf (&sw->info, buf, to_clear);
130     return to_clear << sw->info.shift;
131 }
132 
133 static int no_ctl_in (HWVoiceIn *hw, int cmd, ...)
134 {
135     (void) hw;
136     (void) cmd;
137     return 0;
138 }
139 
140 static void *no_audio_init(Audiodev *dev)
141 {
142     return &no_audio_init;
143 }
144 
145 static void no_audio_fini (void *opaque)
146 {
147     (void) opaque;
148 }
149 
150 static struct audio_pcm_ops no_pcm_ops = {
151     .init_out = no_init_out,
152     .fini_out = no_fini_out,
153     .run_out  = no_run_out,
154     .write    = no_write,
155     .ctl_out  = no_ctl_out,
156 
157     .init_in  = no_init_in,
158     .fini_in  = no_fini_in,
159     .run_in   = no_run_in,
160     .read     = no_read,
161     .ctl_in   = no_ctl_in
162 };
163 
164 static struct audio_driver no_audio_driver = {
165     .name           = "none",
166     .descr          = "Timer based audio emulation",
167     .init           = no_audio_init,
168     .fini           = no_audio_fini,
169     .pcm_ops        = &no_pcm_ops,
170     .can_be_default = 1,
171     .max_voices_out = INT_MAX,
172     .max_voices_in  = INT_MAX,
173     .voice_size_out = sizeof (NoVoiceOut),
174     .voice_size_in  = sizeof (NoVoiceIn)
175 };
176 
177 static void register_audio_none(void)
178 {
179     audio_driver_register(&no_audio_driver);
180 }
181 type_init(register_audio_none);
182