xref: /openbmc/qemu/audio/noaudio.c (revision 52c95cae)
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 #include "qemu/osdep.h"
25 #include "qemu-common.h"
26 #include "qemu/host-utils.h"
27 #include "audio.h"
28 #include "qemu/timer.h"
29 
30 #define AUDIO_CAP "noaudio"
31 #include "audio_int.h"
32 
33 typedef struct NoVoiceOut {
34     HWVoiceOut hw;
35     int64_t old_ticks;
36 } NoVoiceOut;
37 
38 typedef struct NoVoiceIn {
39     HWVoiceIn hw;
40     int64_t old_ticks;
41 } NoVoiceIn;
42 
43 static int no_run_out (HWVoiceOut *hw, int live)
44 {
45     NoVoiceOut *no = (NoVoiceOut *) hw;
46     int decr, samples;
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     bytes = audio_MIN(bytes, INT_MAX);
55     samples = bytes >> hw->info.shift;
56 
57     no->old_ticks = now;
58     decr = audio_MIN (live, samples);
59     hw->rpos = (hw->rpos + decr) % hw->samples;
60     return decr;
61 }
62 
63 static int no_write (SWVoiceOut *sw, void *buf, int len)
64 {
65     return audio_pcm_sw_write(sw, buf, len);
66 }
67 
68 static int no_init_out(HWVoiceOut *hw, struct audsettings *as, void *drv_opaque)
69 {
70     audio_pcm_init_info (&hw->info, as);
71     hw->samples = 1024;
72     return 0;
73 }
74 
75 static void no_fini_out (HWVoiceOut *hw)
76 {
77     (void) hw;
78 }
79 
80 static int no_ctl_out (HWVoiceOut *hw, int cmd, ...)
81 {
82     (void) hw;
83     (void) cmd;
84     return 0;
85 }
86 
87 static int no_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
88 {
89     audio_pcm_init_info (&hw->info, as);
90     hw->samples = 1024;
91     return 0;
92 }
93 
94 static void no_fini_in (HWVoiceIn *hw)
95 {
96     (void) hw;
97 }
98 
99 static int no_run_in (HWVoiceIn *hw)
100 {
101     NoVoiceIn *no = (NoVoiceIn *) hw;
102     int live = audio_pcm_hw_get_live_in (hw);
103     int dead = hw->samples - live;
104     int samples = 0;
105 
106     if (dead) {
107         int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
108         int64_t ticks = now - no->old_ticks;
109         int64_t bytes =
110             muldiv64(ticks, hw->info.bytes_per_second, NANOSECONDS_PER_SECOND);
111 
112         no->old_ticks = now;
113         bytes = audio_MIN (bytes, INT_MAX);
114         samples = bytes >> hw->info.shift;
115         samples = audio_MIN (samples, dead);
116     }
117     return samples;
118 }
119 
120 static int no_read (SWVoiceIn *sw, void *buf, int size)
121 {
122     /* use custom code here instead of audio_pcm_sw_read() to avoid
123      * useless resampling/mixing */
124     int samples = size >> sw->info.shift;
125     int total = sw->hw->total_samples_captured - sw->total_hw_samples_acquired;
126     int to_clear = audio_MIN (samples, total);
127     sw->total_hw_samples_acquired += total;
128     audio_pcm_info_clear_buf (&sw->info, buf, to_clear);
129     return to_clear << sw->info.shift;
130 }
131 
132 static int no_ctl_in (HWVoiceIn *hw, int cmd, ...)
133 {
134     (void) hw;
135     (void) cmd;
136     return 0;
137 }
138 
139 static void *no_audio_init (void)
140 {
141     return &no_audio_init;
142 }
143 
144 static void no_audio_fini (void *opaque)
145 {
146     (void) opaque;
147 }
148 
149 static struct audio_pcm_ops no_pcm_ops = {
150     .init_out = no_init_out,
151     .fini_out = no_fini_out,
152     .run_out  = no_run_out,
153     .write    = no_write,
154     .ctl_out  = no_ctl_out,
155 
156     .init_in  = no_init_in,
157     .fini_in  = no_fini_in,
158     .run_in   = no_run_in,
159     .read     = no_read,
160     .ctl_in   = no_ctl_in
161 };
162 
163 static struct audio_driver no_audio_driver = {
164     .name           = "none",
165     .descr          = "Timer based audio emulation",
166     .options        = NULL,
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