1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Digital Audio (PCM) abstract layer
* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
*/
#include <linux/time.h>
#include <linux/gcd.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/timer.h>
#include "pcm_local.h"
/*
* Timer functions
*/
void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream)
{
unsigned long rate, mult, fsize, l, post;
struct snd_pcm_runtime *runtime = substream->runtime;
mult = 1000000000;
rate = runtime->rate;
if (snd_BUG_ON(!rate))
return;
l = gcd(mult, rate);
mult /= l;
rate /= l;
fsize = runtime->period_size;
if (snd_BUG_ON(!fsize))
return;
l = gcd(rate, fsize);
rate /= l;
fsize /= l;
post = 1;
while ((mult * fsize) / fsize != mult) {
mult /= 2;
post *= 2;
}
if (rate == 0) {
pcm_err(substream->pcm,
"pcm timer resolution out of range (rate = %u, period_size = %lu)\n",
runtime->rate, runtime->period_size);
runtime->timer_resolution = -1;
return;
}
runtime->timer_resolution = (mult * fsize / rate) * post;
}
static unsigned long snd_pcm_timer_resolution(struct snd_timer * timer)
{
struct snd_pcm_substream *substream;
substream = timer->private_data;
return substream->runtime ? substream->runtime->timer_resolution : 0;
}
static int snd_pcm_timer_start(struct snd_timer * timer)
{
struct snd_pcm_substream *substream;
substream = snd_timer_chip(timer);
substream->timer_running = 1;
return 0;
}
static int snd_pcm_timer_stop(struct snd_timer * timer)
{
struct snd_pcm_substream *substream;
substream = snd_timer_chip(timer);
substream->timer_running = 0;
return 0;
}
static const struct snd_timer_hardware snd_pcm_timer =
{
.flags = SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_SLAVE,
.resolution = 0,
.ticks = 1,
.c_resolution = snd_pcm_timer_resolution,
.start = snd_pcm_timer_start,
.stop = snd_pcm_timer_stop,
};
/*
* Init functions
*/
static void snd_pcm_timer_free(struct snd_timer *timer)
{
struct snd_pcm_substream *substream = timer->private_data;
substream->timer = NULL;
}
void snd_pcm_timer_init(struct snd_pcm_substream *substream)
{
struct snd_timer_id tid;
struct snd_timer *timer;
tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
tid.dev_class = SNDRV_TIMER_CLASS_PCM;
tid.card = substream->pcm->card->number;
tid.device = substream->pcm->device;
tid.subdevice = (substream->number << 1) | (substream->stream & 1);
if (snd_timer_new(substream->pcm->card, "PCM", &tid, &timer) < 0)
return;
sprintf(timer->name, "PCM %s %i-%i-%i",
substream->stream == SNDRV_PCM_STREAM_CAPTURE ?
"capture" : "playback",
tid.card, tid.device, tid.subdevice);
timer->hw = snd_pcm_timer;
if (snd_device_register(timer->card, timer) < 0) {
snd_device_free(timer->card, timer);
return;
}
timer->private_data = substream;
timer->private_free = snd_pcm_timer_free;
substream->timer = timer;
}
void snd_pcm_timer_done(struct snd_pcm_substream *substream)
{
if (substream->timer) {
snd_device_free(substream->pcm->card, substream->timer);
substream->timer = NULL;
}
}
|
