iwlagn: add IQ inversion support for 2000 series devices
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / sound / core / pcm_timer.c
blobb01d9481d632c4245d3403a445e6e641b9b2e2aa
1 /*
2 * Digital Audio (PCM) abstract layer
3 * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/time.h>
23 #include <linux/gcd.h>
24 #include <sound/core.h>
25 #include <sound/pcm.h>
26 #include <sound/timer.h>
29 * Timer functions
32 void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream)
34 unsigned long rate, mult, fsize, l, post;
35 struct snd_pcm_runtime *runtime = substream->runtime;
37 mult = 1000000000;
38 rate = runtime->rate;
39 if (snd_BUG_ON(!rate))
40 return;
41 l = gcd(mult, rate);
42 mult /= l;
43 rate /= l;
44 fsize = runtime->period_size;
45 if (snd_BUG_ON(!fsize))
46 return;
47 l = gcd(rate, fsize);
48 rate /= l;
49 fsize /= l;
50 post = 1;
51 while ((mult * fsize) / fsize != mult) {
52 mult /= 2;
53 post *= 2;
55 if (rate == 0) {
56 snd_printk(KERN_ERR "pcm timer resolution out of range (rate = %u, period_size = %lu)\n", runtime->rate, runtime->period_size);
57 runtime->timer_resolution = -1;
58 return;
60 runtime->timer_resolution = (mult * fsize / rate) * post;
63 static unsigned long snd_pcm_timer_resolution(struct snd_timer * timer)
65 struct snd_pcm_substream *substream;
67 substream = timer->private_data;
68 return substream->runtime ? substream->runtime->timer_resolution : 0;
71 static int snd_pcm_timer_start(struct snd_timer * timer)
73 struct snd_pcm_substream *substream;
75 substream = snd_timer_chip(timer);
76 substream->timer_running = 1;
77 return 0;
80 static int snd_pcm_timer_stop(struct snd_timer * timer)
82 struct snd_pcm_substream *substream;
84 substream = snd_timer_chip(timer);
85 substream->timer_running = 0;
86 return 0;
89 static struct snd_timer_hardware snd_pcm_timer =
91 .flags = SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_SLAVE,
92 .resolution = 0,
93 .ticks = 1,
94 .c_resolution = snd_pcm_timer_resolution,
95 .start = snd_pcm_timer_start,
96 .stop = snd_pcm_timer_stop,
100 * Init functions
103 static void snd_pcm_timer_free(struct snd_timer *timer)
105 struct snd_pcm_substream *substream = timer->private_data;
106 substream->timer = NULL;
109 void snd_pcm_timer_init(struct snd_pcm_substream *substream)
111 struct snd_timer_id tid;
112 struct snd_timer *timer;
114 tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
115 tid.dev_class = SNDRV_TIMER_CLASS_PCM;
116 tid.card = substream->pcm->card->number;
117 tid.device = substream->pcm->device;
118 tid.subdevice = (substream->number << 1) | (substream->stream & 1);
119 if (snd_timer_new(substream->pcm->card, "PCM", &tid, &timer) < 0)
120 return;
121 sprintf(timer->name, "PCM %s %i-%i-%i",
122 substream->stream == SNDRV_PCM_STREAM_CAPTURE ?
123 "capture" : "playback",
124 tid.card, tid.device, tid.subdevice);
125 timer->hw = snd_pcm_timer;
126 if (snd_device_register(timer->card, timer) < 0) {
127 snd_device_free(timer->card, timer);
128 return;
130 timer->private_data = substream;
131 timer->private_free = snd_pcm_timer_free;
132 substream->timer = timer;
135 void snd_pcm_timer_done(struct snd_pcm_substream *substream)
137 if (substream->timer) {
138 snd_device_free(substream->pcm->card, substream->timer);
139 substream->timer = NULL;