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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 00:20:36 +0200
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-17 00:20:36 +0200
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /sound/core/pcm_timer.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz
linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'sound/core/pcm_timer.c')
-rw-r--r--sound/core/pcm_timer.c161
1 files changed, 161 insertions, 0 deletions
diff --git a/sound/core/pcm_timer.c b/sound/core/pcm_timer.c
new file mode 100644
index 000000000000..884eaea31fec
--- /dev/null
+++ b/sound/core/pcm_timer.c
@@ -0,0 +1,161 @@
+/*
+ * Digital Audio (PCM) abstract layer
+ * Copyright (c) by Jaroslav Kysela <perex@suse.cz>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <sound/driver.h>
+#include <linux/time.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/timer.h>
+
+/*
+ * Timer functions
+ */
+
+/* Greatest common divisor */
+static unsigned long gcd(unsigned long a, unsigned long b)
+{
+ unsigned long r;
+ if (a < b) {
+ r = a;
+ a = b;
+ b = r;
+ }
+ while ((r = a % b) != 0) {
+ a = b;
+ b = r;
+ }
+ return b;
+}
+
+void snd_pcm_timer_resolution_change(snd_pcm_substream_t *substream)
+{
+ unsigned long rate, mult, fsize, l, post;
+ snd_pcm_runtime_t *runtime = substream->runtime;
+
+ mult = 1000000000;
+ rate = runtime->rate;
+ snd_assert(rate != 0, return);
+ l = gcd(mult, rate);
+ mult /= l;
+ rate /= l;
+ fsize = runtime->period_size;
+ snd_assert(fsize != 0, return);
+ l = gcd(rate, fsize);
+ rate /= l;
+ fsize /= l;
+ post = 1;
+ while ((mult * fsize) / fsize != mult) {
+ mult /= 2;
+ post *= 2;
+ }
+ if (rate == 0) {
+ snd_printk(KERN_ERR "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(snd_timer_t * timer)
+{
+ snd_pcm_substream_t * substream;
+
+ substream = timer->private_data;
+ return substream->runtime ? substream->runtime->timer_resolution : 0;
+}
+
+static int snd_pcm_timer_start(snd_timer_t * timer)
+{
+ unsigned long flags;
+ snd_pcm_substream_t * substream;
+
+ substream = snd_timer_chip(timer);
+ spin_lock_irqsave(&substream->timer_lock, flags);
+ substream->timer_running = 1;
+ spin_unlock_irqrestore(&substream->timer_lock, flags);
+ return 0;
+}
+
+static int snd_pcm_timer_stop(snd_timer_t * timer)
+{
+ unsigned long flags;
+ snd_pcm_substream_t * substream;
+
+ substream = snd_timer_chip(timer);
+ spin_lock_irqsave(&substream->timer_lock, flags);
+ substream->timer_running = 0;
+ spin_unlock_irqrestore(&substream->timer_lock, flags);
+ return 0;
+}
+
+static 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(snd_timer_t *timer)
+{
+ snd_pcm_substream_t *substream = timer->private_data;
+ substream->timer = NULL;
+}
+
+void snd_pcm_timer_init(snd_pcm_substream_t *substream)
+{
+ snd_timer_id_t tid;
+ snd_timer_t *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(snd_pcm_substream_t *substream)
+{
+ if (substream->timer) {
+ snd_device_free(substream->pcm->card, substream->timer);
+ substream->timer = NULL;
+ }
+}