From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?=
 <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 sound/core/pcm_timer.c | 143 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 143 insertions(+)
 create mode 100644 sound/core/pcm_timer.c

(limited to 'sound/core/pcm_timer.c')

diff --git a/sound/core/pcm_timer.c b/sound/core/pcm_timer.c
new file mode 100644
index 000000000..20ecd8f18
--- /dev/null
+++ b/sound/core/pcm_timer.c
@@ -0,0 +1,143 @@
+/*
+ *  Digital Audio (PCM) abstract layer
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.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 <linux/time.h>
+#include <linux/gcd.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/timer.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 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;
+	}
+}
-- 
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