external: tinycompress: add support for compress plugins

Add plugin support to use vendor specific compress implementation

Bug: 166667071
Test: manual offload playback test
Test: cts AudioTrackOffloadTest

CRs-Fixed: 2563258
Change-Id: I71f588b9ed84b62d3b1b08dae7ce65f8fa649e6a

8 files changed, 1003 insertions, 105 deletions

diff --git a/Android.bp b/Android.bp
index f0000f1..c11a974 100644
--- a/Android.bp
+++ b/Android.bp
@@ -12,6 +12,9 @@ cc_library_shared {
     srcs: [
         "compress.c",
         "utils.c",
+        "compress_hw.c",
+         "compress_plugin.c",
+         "snd_utils.c",
     ],
     shared_libs: [
         "libcutils",
diff --git a/compress.c b/compress.c
index 5845cae..7422c4b 100644
--- a/compress.c
+++ b/compress.c
@@ -75,6 +75,8 @@
 #include "sound/compress_params.h"
 #include "sound/compress_offload.h"
 #include "tinycompress/tinycompress.h"
+#include "compress_ops.h"
+#include "snd_utils.h"
 
 #define COMPR_ERR_MAX 128
 
@@ -91,8 +93,15 @@ struct compress {
 	int nonblocking;
 	unsigned int gapless_metadata;
 	unsigned int next_track;
+
+	struct compress_ops *ops;
+	void *data;
+	void *snd_node;
 };
 
+extern struct compress_ops compr_hw_ops;
+extern struct compress_ops compr_plug_ops;
+
 static int oops(struct compress *compress, int e, const char *fmt, ...)
 {
 	va_list ap;
@@ -120,75 +129,33 @@ static struct compress bad_compress = {
 
 int is_compress_running(struct compress *compress)
 {
-	return ((compress->fd > 0) && compress->running) ? 1 : 0;
+	return ((compress->fd >= 0) && compress->running) ? 1 : 0;
 }
 
 int is_compress_ready(struct compress *compress)
 {
-	return (compress->fd > 0) ? 1 : 0;
+	return (compress->fd >= 0) ? 1 : 0;
 }
 
 static int get_compress_version(struct compress *compress)
 {
 	int version = 0;
 
-	if (ioctl(compress->fd, SNDRV_COMPRESS_IOCTL_VERSION, &version)) {
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_IOCTL_VERSION, &version)) {
 		oops(compress, errno, "cant read version");
 		return -1;
 	}
 	return version;
 }
 
-static bool _is_codec_supported(struct compress *compress, struct compr_config *config,
-				const struct snd_compr_caps *caps)
-{
-	bool codec = false;
-	unsigned int i;
-
-	for (i = 0; i < caps->num_codecs; i++) {
-		if (caps->codecs[i] == config->codec->id) {
-			/* found the codec */
-			codec = true;
-			break;
-		}
-	}
-	if (codec == false) {
-		oops(compress, ENXIO, "this codec is not supported");
-		return false;
-	}
-
-	if (config->fragment_size < caps->min_fragment_size) {
-		oops(compress, EINVAL, "requested fragment size %d is below min supported %d",
-			config->fragment_size, caps->min_fragment_size);
-		return false;
-	}
-	if (config->fragment_size > caps->max_fragment_size) {
-		oops(compress, EINVAL, "requested fragment size %d is above max supported %d",
-			config->fragment_size, caps->max_fragment_size);
-		return false;
-	}
-	if (config->fragments < caps->min_fragments) {
-		oops(compress, EINVAL, "requested fragments %d are below min supported %d",
-			config->fragments, caps->min_fragments);
-		return false;
-	}
-	if (config->fragments > caps->max_fragments) {
-		oops(compress, EINVAL, "requested fragments %d are above max supported %d",
-			config->fragments, caps->max_fragments);
-		return false;
-	}
-
-	/* TODO: match the codec properties */
-	return true;
-}
-
-static bool _is_codec_type_supported(int fd, struct snd_codec *codec)
+static bool _is_codec_type_supported(struct compress_ops *ops, void *data,
+		struct snd_codec *codec)
 {
 	struct snd_compr_caps caps;
 	bool found = false;
 	unsigned int i;
 
-	if (ioctl(fd, SNDRV_COMPRESS_GET_CAPS, &caps)) {
+	if (ops->ioctl(data, SNDRV_COMPRESS_GET_CAPS, &caps)) {
 		oops(&bad_compress, errno, "cannot get device caps");
 		return false;
 	}
@@ -218,7 +185,7 @@ struct compress *compress_open(unsigned int card, unsigned int device,
 	struct compress *compress;
 	struct snd_compr_params params;
 	struct snd_compr_caps caps;
-	char fn[256];
+	int compress_type;
 
 	if (!config) {
 		oops(&bad_compress, EINVAL, "passed bad config");
@@ -237,8 +204,6 @@ struct compress *compress_open(unsigned int card, unsigned int device,
 	if (!compress->config)
 		goto input_fail;
 
-	snprintf(fn, sizeof(fn), "/dev/snd/comprC%uD%u", card, device);
-
 	compress->max_poll_wait_ms = DEFAULT_MAX_POLL_WAIT_MS;
 
 	compress->flags = flags;
@@ -247,17 +212,22 @@ struct compress *compress_open(unsigned int card, unsigned int device,
 		goto config_fail;
 	}
 
-	if (flags & COMPRESS_OUT) {
-		compress->fd = open(fn, O_RDONLY);
-	} else {
-		compress->fd = open(fn, O_WRONLY);
-	}
+	compress->snd_node = snd_utils_get_dev_node(card, device, NODE_COMPRESS);
+	compress_type = snd_utils_get_node_type(compress->snd_node);
+	if (compress_type == SND_NODE_TYPE_PLUGIN)
+		compress->ops = &compr_plug_ops;
+	else
+		compress->ops = &compr_hw_ops;
+
+	compress->fd = compress->ops->open(card, device, flags,
+									   &compress->data, compress->snd_node);
 	if (compress->fd < 0) {
-		oops(&bad_compress, errno, "cannot open device '%s'", fn);
+		oops(&bad_compress, errno, "cannot open card(%u) device(%u)",
+			card, device);
 		goto config_fail;
 	}
 
-	if (ioctl(compress->fd, SNDRV_COMPRESS_GET_CAPS, &caps)) {
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_GET_CAPS, &caps)) {
 		oops(compress, errno, "cannot get device caps");
 		goto codec_fail;
 	}
@@ -281,7 +251,7 @@ struct compress *compress_open(unsigned int card, unsigned int device,
 	memcpy(compress->config, config, sizeof(*compress->config));
 	fill_compress_params(config, &params);
 
-	if (ioctl(compress->fd, SNDRV_COMPRESS_SET_PARAMS, &params)) {
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_SET_PARAMS, &params)) {
 		oops(&bad_compress, errno, "cannot set device");
 		goto codec_fail;
 	}
@@ -289,7 +259,8 @@ struct compress *compress_open(unsigned int card, unsigned int device,
 	return compress;
 
 codec_fail:
-	close(compress->fd);
+	snd_utils_put_dev_node(compress->snd_node);
+	compress->ops->close(compress->data);
 	compress->fd = -1;
 config_fail:
 	free(compress->config);
@@ -303,8 +274,8 @@ void compress_close(struct compress *compress)
 	if (compress == &bad_compress)
 		return;
 
-	if (compress->fd >= 0)
-		close(compress->fd);
+	snd_utils_put_dev_node(compress->snd_node);
+	compress->ops->close(compress->data);
 	compress->running = 0;
 	compress->fd = -1;
 	free(compress->config);
@@ -320,7 +291,7 @@ int compress_get_hpointer(struct compress *compress,
 	if (!is_compress_ready(compress))
 		return oops(compress, ENODEV, "device not ready");
 
-	if (ioctl(compress->fd, SNDRV_COMPRESS_AVAIL, &kavail))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_AVAIL, &kavail))
 		return oops(compress, errno, "cannot get avail");
 	if (0 == kavail.tstamp.sampling_rate)
 		return oops(compress, ENODATA, "sample rate unknown");
@@ -340,7 +311,7 @@ int compress_get_tstamp(struct compress *compress,
 	if (!is_compress_ready(compress))
 		return oops(compress, ENODEV, "device not ready");
 
-	if (ioctl(compress->fd, SNDRV_COMPRESS_TSTAMP, &ktstamp))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_TSTAMP, &ktstamp))
 		return oops(compress, errno, "cannot get tstamp");
 
 	*samples = ktstamp.pcm_io_frames;
@@ -361,12 +332,11 @@ int compress_write(struct compress *compress, const void *buf, unsigned int size
 		return oops(compress, EINVAL, "Invalid flag set");
 	if (!is_compress_ready(compress))
 		return oops(compress, ENODEV, "device not ready");
-	fds.fd = compress->fd;
 	fds.events = POLLOUT;
 
 	/*TODO: treat auto start here first */
 	while (size) {
-		if (ioctl(compress->fd, SNDRV_COMPRESS_AVAIL, &avail))
+		if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_AVAIL, &avail))
 			return oops(compress, errno, "cannot get avail");
 
 		/* We can write if we have at least one fragment available
@@ -377,13 +347,14 @@ int compress_write(struct compress *compress, const void *buf, unsigned int size
 			if (compress->nonblocking)
 				return total;
 
-			ret = poll(&fds, 1, compress->max_poll_wait_ms);
+			ret = compress->ops->poll(compress->data, &fds, 1,
+								compress->max_poll_wait_ms);
 			if (fds.revents & POLLERR) {
 				return oops(compress, EIO, "poll returned error!");
 			}
 			/* A pause will cause -EBADFD or zero.
 			 * This is not an error, just stop writing */
-			if ((ret == 0) || (ret == -EBADFD))
+			if ((ret == 0) || (ret < 0 && errno == EBADFD))
 				break;
 			if (ret < 0)
 				return oops(compress, errno, "poll error");
@@ -396,12 +367,13 @@ int compress_write(struct compress *compress, const void *buf, unsigned int size
 			to_write =  avail.avail;
 		else
 			to_write = size;
-		written = write(compress->fd, cbuf, to_write);
-		/* If play was paused the write returns -EBADFD */
-		if (written == -EBADFD)
-			break;
-		if (written < 0)
+		written = compress->ops->write(compress->data, cbuf, to_write);
+		if (written < 0) {
+			/* If play was paused the write returns -EBADFD */
+			if (errno == EBADFD)
+				break;
 			return oops(compress, errno, "write failed!");
+		}
 
 		size -= written;
 		cbuf += written;
@@ -423,11 +395,10 @@ int compress_read(struct compress *compress, void *buf, unsigned int size)
 		return oops(compress, EINVAL, "Invalid flag set");
 	if (!is_compress_ready(compress))
 		return oops(compress, ENODEV, "device not ready");
-	fds.fd = compress->fd;
 	fds.events = POLLIN;
 
 	while (size) {
-		if (ioctl(compress->fd, SNDRV_COMPRESS_AVAIL, &avail))
+		if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_AVAIL, &avail))
 			return oops(compress, errno, "cannot get avail");
 
 		if ( (avail.avail < frag_size) && (avail.avail < size) ) {
@@ -437,13 +408,14 @@ int compress_read(struct compress *compress, void *buf, unsigned int size)
 			if (compress->nonblocking)
 				return total;
 
-			ret = poll(&fds, 1, compress->max_poll_wait_ms);
+			ret = compress->ops->poll(compress->data, &fds, 1,
+							compress->max_poll_wait_ms);
 			if (fds.revents & POLLERR) {
 				return oops(compress, EIO, "poll returned error!");
 			}
 			/* A pause will cause -EBADFD or zero.
 			 * This is not an error, just stop reading */
-			if ((ret == 0) || (ret == -EBADFD))
+			if ((ret == 0) || (ret < 0 && errno == EBADFD))
 				break;
 			if (ret < 0)
 				return oops(compress, errno, "poll error");
@@ -456,12 +428,13 @@ int compress_read(struct compress *compress, void *buf, unsigned int size)
 			to_read = avail.avail;
 		else
 			to_read = size;
-		num_read = read(compress->fd, cbuf, to_read);
-		/* If play was paused the read returns -EBADFD */
-		if (num_read == -EBADFD)
-			break;
-		if (num_read < 0)
+		num_read = compress->ops->read(compress->data, cbuf, to_read);
+		if (num_read < 0) {
+			/* If play was paused the read returns -EBADFD */
+			if (errno == EBADFD)
+				break;
 			return oops(compress, errno, "read failed!");
+		}
 
 		size -= num_read;
 		cbuf += num_read;
@@ -475,7 +448,7 @@ int compress_start(struct compress *compress)
 {
 	if (!is_compress_ready(compress))
 		return oops(compress, ENODEV, "device not ready");
-	if (ioctl(compress->fd, SNDRV_COMPRESS_START))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_START))
 		return oops(compress, errno, "cannot start the stream");
 	compress->running = 1;
 	return 0;
@@ -486,7 +459,7 @@ int compress_stop(struct compress *compress)
 {
 	if (!is_compress_running(compress))
 		return oops(compress, ENODEV, "device not ready");
-	if (ioctl(compress->fd, SNDRV_COMPRESS_STOP))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_STOP))
 		return oops(compress, errno, "cannot stop the stream");
 	return 0;
 }
@@ -495,14 +468,14 @@ int compress_pause(struct compress *compress)
 {
 	if (!is_compress_running(compress))
 		return oops(compress, ENODEV, "device not ready");
-	if (ioctl(compress->fd, SNDRV_COMPRESS_PAUSE))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_PAUSE))
 		return oops(compress, errno, "cannot pause the stream");
 	return 0;
 }
 
 int compress_resume(struct compress *compress)
 {
-	if (ioctl(compress->fd, SNDRV_COMPRESS_RESUME))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_RESUME))
 		return oops(compress, errno, "cannot resume the stream");
 	return 0;
 }
@@ -511,7 +484,7 @@ int compress_drain(struct compress *compress)
 {
 	if (!is_compress_running(compress))
 		return oops(compress, ENODEV, "device not ready");
-	if (ioctl(compress->fd, SNDRV_COMPRESS_DRAIN))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_DRAIN))
 		return oops(compress, errno, "cannot drain the stream");
 	return 0;
 }
@@ -523,7 +496,7 @@ int compress_partial_drain(struct compress *compress)
 
 	if (!compress->next_track)
 		return oops(compress, EPERM, "next track not signalled");
-	if (ioctl(compress->fd, SNDRV_COMPRESS_PARTIAL_DRAIN))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_PARTIAL_DRAIN))
 		return oops(compress, errno, "cannot drain the stream\n");
 	compress->next_track = 0;
 	return 0;
@@ -536,7 +509,7 @@ int compress_next_track(struct compress *compress)
 
 	if (!compress->gapless_metadata)
 		return oops(compress, EPERM, "metadata not set");
-	if (ioctl(compress->fd, SNDRV_COMPRESS_NEXT_TRACK))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_NEXT_TRACK))
 		return oops(compress, errno, "cannot set next track\n");
 	compress->next_track = 1;
 	compress->gapless_metadata = 0;
@@ -561,12 +534,12 @@ int compress_set_gapless_metadata(struct compress *compress,
 
 	metadata.key = SNDRV_COMPRESS_ENCODER_PADDING;
 	metadata.value[0] = mdata->encoder_padding;
-	if (ioctl(compress->fd, SNDRV_COMPRESS_SET_METADATA, &metadata))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_SET_METADATA, &metadata))
 		return oops(compress, errno, "can't set metadata for stream\n");
 
 	metadata.key = SNDRV_COMPRESS_ENCODER_DELAY;
 	metadata.value[0] = mdata->encoder_delay;
-	if (ioctl(compress->fd, SNDRV_COMPRESS_SET_METADATA, &metadata))
+	if (compress->ops->ioctl(compress->data, SNDRV_COMPRESS_SET_METADATA, &metadata))
 		return oops(compress, errno, "can't set metadata for stream\n");
 	compress->gapless_metadata = 1;
 	return 0;
@@ -588,25 +561,27 @@ int compress_set_next_track_param(struct compress *compress,
 bool is_codec_supported(unsigned int card, unsigned int device,
 		unsigned int flags, struct snd_codec *codec)
 {
-	unsigned int dev_flag;
+	struct compress_ops *ops;
+	void *snd_node, *data;
 	bool ret;
-	int fd;
-	char fn[256];
-
-	snprintf(fn, sizeof(fn), "/dev/snd/comprC%uD%u", card, device);
+	int compress_type, fd;
 
-	if (flags & COMPRESS_OUT)
-		dev_flag = O_RDONLY;
+	snd_node = snd_utils_get_dev_node(card, device, NODE_COMPRESS);
+	compress_type = snd_utils_get_node_type(snd_node);
+	if (compress_type == SND_NODE_TYPE_PLUGIN)
+		ops = &compr_plug_ops;
 	else
-		dev_flag = O_WRONLY;
+		ops = &compr_hw_ops;
 
-	fd = open(fn, dev_flag);
+	fd = ops->open(card, device, flags, &data, NULL);
 	if (fd < 0)
-		return oops(&bad_compress, errno, "cannot open device '%s'", fn);
+		return oops(&bad_compress, errno, "cannot open card %u, device %u",
+					card, device);
 
-	ret = _is_codec_type_supported(fd, codec);
+	ret = _is_codec_type_supported(ops, data, codec);
 
-	close(fd);
+	snd_utils_put_dev_node(snd_node);
+	ops->close(data);
 	return ret;
 }
 
@@ -625,10 +600,9 @@ int compress_wait(struct compress *compress, int timeout_ms)
 	struct pollfd fds;
 	int ret;
 
-	fds.fd = compress->fd;
 	fds.events = POLLOUT | POLLIN;
 
-	ret = poll(&fds, 1, timeout_ms);
+	ret = compress->ops->poll(compress->data, &fds, 1, timeout_ms);
 	if (ret > 0) {
 		if (fds.revents & POLLERR)
 			return oops(compress, EIO, "poll returned error!");
diff --git a/compress_hw.c b/compress_hw.c
new file mode 100644
index 0000000..b2252cc
--- /dev/null
+++ b/compress_hw.c
@@ -0,0 +1,138 @@
+/* compress_hw.c
+**
+** Copyright (c) 2019, The Linux Foundation. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <unistd.h>
+#include <poll.h>
+
+#include <sys/ioctl.h>
+#include <linux/ioctl.h>
+#include <sound/asound.h>
+#include "tinycompress/tinycompress.h"
+#include "compress_ops.h"
+
+struct compress_hw_data {
+	unsigned int card;
+	unsigned int device;
+	unsigned int fd;
+};
+
+static int compress_hw_poll(void *data, struct pollfd *fds,
+				nfds_t nfds, int timeout)
+{
+	struct compress_hw_data *hw_data = data;
+
+	fds->fd = hw_data->fd;
+	return poll(fds, nfds, timeout);
+}
+
+static int compress_hw_write(void *data, const void *buf, size_t size)
+{
+	struct compress_hw_data *hw_data = data;
+
+	return write(hw_data->fd, buf, size);
+}
+
+static int compress_hw_read(void *data, void *buf, size_t size)
+{
+	struct compress_hw_data *hw_data = data;
+
+	return read(hw_data->fd, buf, size);
+}
+
+static int compress_hw_ioctl(void *data, unsigned int cmd, ...)
+{
+	struct compress_hw_data *hw_data = data;
+	va_list ap;
+	void *arg;
+
+	va_start(ap, cmd);
+	arg = va_arg(ap, void *);
+	va_end(ap);
+
+	return ioctl(hw_data->fd, cmd, arg);
+}
+
+static void compress_hw_close(void *data)
+{
+	struct compress_hw_data *hw_data = data;
+
+	if (hw_data->fd > 0)
+		close(hw_data->fd);
+
+	free(hw_data);
+}
+
+static int compress_hw_open(unsigned int card, unsigned int device,
+		unsigned int flags, void **data, __unused void *node)
+{
+	struct compress_hw_data *hw_data;
+	char fn[256];
+	int fd;
+
+	hw_data = calloc(1, sizeof(*hw_data));
+	if (!hw_data) {
+		return -ENOMEM;
+	}
+
+	snprintf(fn, sizeof(fn), "/dev/snd/comprC%uD%u", card, device);
+
+	if (flags & COMPRESS_OUT)
+		fd = open(fn,  O_RDONLY);
+	else
+		fd = open(fn, O_WRONLY);
+
+	if (fd < 0) {
+		return fd;
+	}
+
+	hw_data->card = card;
+	hw_data->device = device;
+	hw_data->fd = fd;
+
+	*data = hw_data;
+
+	return fd;
+}
+
+struct compress_ops compr_hw_ops = {
+	.open = compress_hw_open,
+	.close = compress_hw_close,
+	.ioctl = compress_hw_ioctl,
+	.read = compress_hw_read,
+	.write = compress_hw_write,
+	.poll = compress_hw_poll,
+};
diff --git a/compress_ops.h b/compress_ops.h
new file mode 100644
index 0000000..a3147b7
--- /dev/null
+++ b/compress_ops.h
@@ -0,0 +1,50 @@
+/* compress.h
+**
+** Copyright (c) 2019, The Linux Foundation. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#ifndef __COMPRESS_H__
+#define __COMPRESS_H__
+
+#include <poll.h>
+
+#include "sound/compress_params.h"
+#include "sound/compress_offload.h"
+
+struct compress_ops {
+	int (*open) (unsigned int card, unsigned int device,
+			unsigned int flags, void **data, void *node);
+	void (*close) (void *data);
+	int (*ioctl) (void *data, unsigned int cmd, ...);
+	int (*read) (void *data, void *buf, size_t size);
+	int (*write) (void *data, const void *buf, size_t size);
+	int (*poll) (void *data, struct pollfd *fds, nfds_t nfds,
+				 int timeout);
+};
+
+#endif /* end of __PCM_H__ */
diff --git a/compress_plugin.c b/compress_plugin.c
new file mode 100644
index 0000000..d445ae9
--- /dev/null
+++ b/compress_plugin.c
@@ -0,0 +1,423 @@
+/* compress_plugin.c
+**
+** Copyright (c) 2019, The Linux Foundation. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <poll.h>
+#include <dlfcn.h>
+
+#include <sys/ioctl.h>
+#include <linux/ioctl.h>
+#include <sound/asound.h>
+#include "tinycompress/compress_plugin.h"
+#include "sound/compress_offload.h"
+#include "compress_ops.h"
+#include "snd_utils.h"
+
+#define U32_MAX	((uint32_t)~0U)
+
+enum {
+	COMPRESS_PLUG_STATE_OPEN,
+	COMPRESS_PLUG_STATE_SETUP,
+	COMPRESS_PLUG_STATE_PREPARED,
+	COMPRESS_PLUG_STATE_PAUSE,
+	COMPRESS_PLUG_STATE_RUNNING,
+};
+
+struct compress_plug_data {
+	unsigned int card;
+	unsigned int device;
+	unsigned int fd;
+	unsigned int flags;
+
+	void *dl_hdl;
+	COMPRESS_PLUGIN_OPEN_FN_PTR();
+
+	struct compress_plugin *plugin;
+	void *dev_node;
+};
+
+static int compress_plug_get_caps(struct compress_plug_data *plug_data,
+		struct snd_compr_caps *caps)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	return plugin->ops->get_caps(plugin, caps);
+}
+
+static int compress_plug_set_params(struct compress_plug_data *plug_data,
+		struct snd_compr_params *params)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+	int rc;
+
+	if (plugin->state != COMPRESS_PLUG_STATE_OPEN)
+		return -EBADFD;
+
+	if (params->buffer.fragment_size == 0 ||
+	   params->buffer.fragments > U32_MAX / params->buffer.fragment_size ||
+	   params->buffer.fragments == 0)
+		return -EINVAL;
+
+	rc = plugin->ops->set_params(plugin, params);
+	if (!rc)
+		plugin->state = COMPRESS_PLUG_STATE_SETUP;
+
+	return rc;
+}
+
+static int compress_plug_avail(struct compress_plug_data *plug_data,
+		struct snd_compr_avail *avail)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	return plugin->ops->avail(plugin, avail);
+}
+
+static int compress_plug_tstamp(struct compress_plug_data *plug_data,
+		struct snd_compr_tstamp *tstamp)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	if (plugin->state != COMPRESS_PLUG_STATE_SETUP)
+		return -EBADFD;
+
+	return plugin->ops->tstamp(plugin, tstamp);
+}
+
+static int compress_plug_start(struct compress_plug_data *plug_data)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+	int rc;
+
+	/* for playback moved to prepare in first write */
+	/* for capture: move to prepare state set params */
+	 /* TODO: add direction in set params */
+	if (plugin->state != COMPRESS_PLUG_STATE_PREPARED)
+		return -EBADFD;
+
+	rc = plugin->ops->start(plugin);
+	if (!rc)
+		plugin->state = COMPRESS_PLUG_STATE_RUNNING;
+
+	return rc;
+}
+
+static int compress_plug_stop(struct compress_plug_data *plug_data)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+	int rc;
+
+	if (plugin->state == COMPRESS_PLUG_STATE_PREPARED ||
+		plugin->state == COMPRESS_PLUG_STATE_SETUP)
+		return -EBADFD;
+
+	rc = plugin->ops->stop(plugin);
+	if (!rc)
+		plugin->state = COMPRESS_PLUG_STATE_SETUP;
+
+	return rc;
+}
+
+static int compress_plug_pause(struct compress_plug_data *plug_data)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+	int rc;
+
+	if (plugin->state != COMPRESS_PLUG_STATE_RUNNING)
+		return -EBADFD;
+
+	rc = plugin->ops->pause(plugin);
+	if (!rc)
+		plugin->state = COMPRESS_PLUG_STATE_PAUSE;
+
+	return rc;
+}
+
+static int compress_plug_resume(struct compress_plug_data *plug_data)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+	int rc;
+
+	if (plugin->state != COMPRESS_PLUG_STATE_PAUSE)
+		return -EBADFD;
+
+	rc = plugin->ops->resume(plugin);
+	if (!rc)
+		plugin->state = COMPRESS_PLUG_STATE_RUNNING;
+
+	return rc;
+}
+
+static int compress_plug_drain(struct compress_plug_data *plug_data)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	/* check if we will allow in pause */
+	if (plugin->state != COMPRESS_PLUG_STATE_RUNNING)
+		return -EBADFD;
+
+	return plugin->ops->drain(plugin);
+}
+
+static int compress_plug_partial_drain(struct compress_plug_data *plug_data)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	 /* check if we will allow in pause */
+	if (plugin->state != COMPRESS_PLUG_STATE_RUNNING)
+		return -EBADFD;
+
+	return plugin->ops->partial_drain(plugin);
+}
+
+static int compress_plug_next_track(struct compress_plug_data *plug_data)
+{
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	/* transion to next track applied to running stream only */
+	if (plugin->state != COMPRESS_PLUG_STATE_RUNNING)
+		return -EBADFD;
+
+	return plugin->ops->next_track(plugin);
+}
+
+static int compress_plug_ioctl(void *data, unsigned int cmd, ...)
+{
+	struct compress_plug_data *plug_data = data;
+	struct compress_plugin *plugin = plug_data->plugin;
+	int ret = 0;
+	va_list ap;
+	void *arg;
+
+	va_start(ap, cmd);
+	arg = va_arg(ap, void *);
+	va_end(ap);
+
+	switch (cmd) {
+	case SNDRV_COMPRESS_IOCTL_VERSION:
+		*((int*)arg) = SNDRV_COMPRESS_VERSION;
+		break;
+	case SNDRV_COMPRESS_GET_CAPS:
+		ret = compress_plug_get_caps(plug_data, arg);
+		break;
+	case SNDRV_COMPRESS_SET_PARAMS:
+		ret = compress_plug_set_params(plug_data, arg);
+		break;
+	case SNDRV_COMPRESS_AVAIL:
+		ret = compress_plug_avail(plug_data, arg);
+		break;
+	case SNDRV_COMPRESS_TSTAMP:
+		ret = compress_plug_tstamp(plug_data, arg);
+		break;
+	case SNDRV_COMPRESS_START:
+		ret = compress_plug_start(plug_data);
+		break;
+	case SNDRV_COMPRESS_STOP:
+		ret = compress_plug_stop(plug_data);
+		break;
+	case SNDRV_COMPRESS_PAUSE:
+		ret = compress_plug_pause(plug_data);
+		break;
+	case SNDRV_COMPRESS_RESUME:
+		ret = compress_plug_resume(plug_data);
+		break;
+	case SNDRV_COMPRESS_DRAIN:
+		ret = compress_plug_drain(plug_data);
+		break;
+	case SNDRV_COMPRESS_PARTIAL_DRAIN:
+		ret = compress_plug_partial_drain(plug_data);
+		break;
+	case SNDRV_COMPRESS_NEXT_TRACK:
+		ret = compress_plug_next_track(plug_data);
+		break;
+	default:
+		if (plugin->ops->ioctl)
+			ret = plugin->ops->ioctl(plugin, cmd, arg);
+		else
+			ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static int compress_plug_poll(void *data, struct pollfd *fds,
+				nfds_t nfds, int timeout)
+{
+	struct compress_plug_data *plug_data = data;
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	if (plugin->state != COMPRESS_PLUG_STATE_RUNNING)
+		return -EBADFD;
+
+	return plugin->ops->poll(plugin, fds, nfds, timeout);
+}
+
+
+static int compress_plug_read(void *data, void *buf, size_t size)
+{
+	struct compress_plug_data *plug_data = data;
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	if (plugin->state != COMPRESS_PLUG_STATE_RUNNING &&
+		plugin->state != COMPRESS_PLUG_STATE_SETUP)
+		return -EBADFD;
+
+	return plugin->ops->read(plugin, buf, size);
+}
+
+static int compress_plug_write(void *data, const void *buf, size_t size)
+{
+	struct compress_plug_data *plug_data = data;
+	struct compress_plugin *plugin = plug_data->plugin;
+	int rc;
+
+	if (plugin->state != COMPRESS_PLUG_STATE_SETUP &&
+	    plugin->state != COMPRESS_PLUG_STATE_PREPARED &&
+	    plugin->state != COMPRESS_PLUG_STATE_RUNNING)
+		return -EBADFD;
+
+	rc = plugin->ops->write(plugin, buf, size);
+	if ((rc > 0) && (plugin->state == COMPRESS_PLUG_STATE_SETUP))
+		plugin->state = COMPRESS_PLUG_STATE_PREPARED;
+
+	return rc;
+}
+
+static void compress_plug_close(void *data)
+{
+	struct compress_plug_data *plug_data = data;
+	struct compress_plugin *plugin = plug_data->plugin;
+
+	plugin->ops->close(plugin);
+	dlclose(plug_data->dl_hdl);
+
+	free(plug_data);
+}
+
+static int compress_plug_open(unsigned int card, unsigned int device,
+			unsigned int flags, void **data, void *node)
+{
+	struct compress_plug_data *plug_data;
+	const char *err = NULL;
+	void *dl_hdl;
+	int rc = 0;
+	char *so_name, *open_fn, token[80], *name;
+
+	plug_data = calloc(1, sizeof(*plug_data));
+	if (!plug_data) {
+		return -ENOMEM;
+	}
+
+	rc = snd_utils_get_str(node, "so-name", &so_name);
+	if (rc) {
+		fprintf(stderr, "%s: failed to get plugin lib name\n",
+				__func__);
+		goto err_get_lib;
+	}
+
+	dl_hdl = dlopen(so_name, RTLD_NOW);
+	if (!dl_hdl) {
+		fprintf(stderr, "%s: unable to open %s, error: %s\n",
+					__func__, so_name, dlerror());
+		goto err_dl_open;
+	} else {
+		fprintf(stderr, "%s: dlopen successful for %s\n",
+					__func__, so_name);
+	}
+
+	sscanf(so_name, "lib%s", token);
+	name = strtok(token, ".");
+	open_fn = calloc(1, strlen(name) + strlen("_open") + 1);
+	if (!open_fn) {
+		rc = -ENOMEM;
+		goto err_open_fn;
+	}
+
+	strncpy(open_fn, name, strlen(name) + 1);
+	strcat(open_fn, "_open");
+
+	plug_data->plugin_open_fn = dlsym(dl_hdl, open_fn);
+	err = dlerror();
+
+	if (err) {
+		fprintf(stderr, "%s: dlsym to open fn failed, err = '%s'\n",
+				__func__, err);
+		goto err_dlsym;
+	}
+
+	rc = plug_data->plugin_open_fn(&plug_data->plugin,
+					card, device, flags);
+	if (rc) {
+		fprintf(stderr, "%s: failed to open plugin\n", __func__);
+		goto err_dlsym;
+	}
+
+	/* Call snd-card-def to get card and compress nodes */
+	/* Check how to manage fd for plugin */
+
+	plug_data->dl_hdl = dl_hdl;
+	plug_data->card = card;
+	plug_data->device = device;
+	plug_data->dev_node = node;
+	plug_data->flags = flags;
+
+	*data = plug_data;
+
+	plug_data->plugin->state = COMPRESS_PLUG_STATE_OPEN;
+
+	return 0;
+
+err_dlsym:
+	free(open_fn);
+err_open_fn:
+	dlclose(dl_hdl);
+err_get_lib:
+err_dl_open:
+	free(plug_data);
+
+	return rc;
+}
+
+struct compress_ops compr_plug_ops = {
+	.open = compress_plug_open,
+	.close = compress_plug_close,
+	.ioctl = compress_plug_ioctl,
+	.read = compress_plug_read,
+	.write = compress_plug_write,
+	.poll = compress_plug_poll,
+};
diff --git a/include/tinycompress/compress_plugin.h b/include/tinycompress/compress_plugin.h
new file mode 100644
index 0000000..abd59f2
--- /dev/null
+++ b/include/tinycompress/compress_plugin.h
@@ -0,0 +1,89 @@
+/* compress_plugin.h
+**
+** Copyright (c) 2019, The Linux Foundation. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#ifndef __COMPRESS_PLUGIN_H__
+#define __COMPRESS_PLUGIN_H__
+
+#include "sound/compress_params.h"
+#include "sound/compress_offload.h"
+
+#define COMPRESS_PLUGIN_OPEN_FN(name)                    \
+	int name##_open(struct compress_plugin **plugin,     \
+			unsigned int card,                   \
+			unsigned int device,                  \
+			unsigned int flags)
+
+#define COMPRESS_PLUGIN_OPEN_FN_PTR()                        \
+	int (*plugin_open_fn) (struct compress_plugin **plugin,  \
+				unsigned int card,                \
+				unsigned int device,               \
+				unsigned int flags);
+
+struct compress_plugin;
+
+struct compress_plugin_ops {
+	void (*close) (struct compress_plugin *plugin);
+	int (*get_caps) (struct compress_plugin *plugin,
+					 struct snd_compr_caps *caps);
+	int (*set_params) (struct compress_plugin *plugin,
+					   struct snd_compr_params *params);
+	int (*avail) (struct compress_plugin *plugin,
+				  struct snd_compr_avail *avail);
+	int (*tstamp) (struct compress_plugin *plugin,
+					 struct snd_compr_tstamp *tstamp);
+	int (*write) (struct compress_plugin *plugin,
+					 const void *buf, size_t size);
+	int (*read) (struct compress_plugin *plugin,
+					 void *buf, size_t size);
+	int (*start) (struct compress_plugin *plugin);
+	int (*stop) (struct compress_plugin *plugin);
+	int (*pause) (struct compress_plugin *plugin);
+	int (*resume) (struct compress_plugin *plugin);
+	int (*drain) (struct compress_plugin *plugin);
+	int (*partial_drain) (struct compress_plugin *plugin);
+	int (*next_track) (struct compress_plugin *plugin);
+	int (*ioctl) (struct compress_plugin *plugin, int cmd, ...);
+	int (*poll) (struct compress_plugin *plugin,
+			struct pollfd *fds, nfds_t nfds, int timeout);
+};
+
+struct compress_plugin {
+	unsigned int card;
+
+	struct compress_plugin_ops *ops;
+
+	void *node;
+	int mode;
+	void *priv;
+
+	unsigned int state;
+};
+
+#endif /* end of __COMPRESS_PLUGIN_H__ */
diff --git a/snd_utils.c b/snd_utils.c
new file mode 100644
index 0000000..2c244cc
--- /dev/null
+++ b/snd_utils.c
@@ -0,0 +1,149 @@
+/* snd_utils.c
+**
+** Copyright (c) 2019, The Linux Foundation. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include "snd_utils.h"
+
+#define SND_DLSYM(h, p, s, err) \
+do {                            \
+	err = 0;                    \
+	p = dlsym(h, s);            \
+	if (!p)                     \
+		err = -ENODEV;          \
+} while(0)
+
+int snd_utils_get_int(struct snd_node *node, const char *prop, int *val)
+{
+	if (!node || !node->card_node || !node->dev_node)
+		return SND_NODE_TYPE_HW;
+
+	return node->get_int(node->dev_node, prop, val);
+}
+
+int snd_utils_get_str(struct snd_node *node, const char *prop, char **val)
+{
+	if (!node || !node->card_node || !node->dev_node)
+		return SND_NODE_TYPE_HW;
+
+	return node->get_str(node->dev_node, prop, val);
+}
+
+void snd_utils_put_dev_node(struct snd_node *node)
+{
+	if (!node)
+		return;
+
+	if (node->card_node)
+		node->put_card(node->card_node);
+
+	if (node->dl_hdl)
+		dlclose(node->dl_hdl);
+
+	free(node);
+}
+
+enum snd_node_type snd_utils_get_node_type(struct snd_node *node)
+{
+	int val = SND_NODE_TYPE_HW;
+
+	if (!node || !node->card_node || !node->dev_node)
+		return SND_NODE_TYPE_HW;
+
+	node->get_int(node->dev_node, "type", &val);
+
+	return val;
+};
+
+
+static int snd_utils_resolve_symbols(struct snd_node *node)
+{
+	void *dl = node->dl_hdl;
+	int err;
+
+	SND_DLSYM(dl, node->get_card, "snd_card_def_get_card", err);
+	if (err)
+		goto done;
+	SND_DLSYM(dl, node->put_card, "snd_card_def_put_card", err);
+	if (err)
+		goto done;
+	SND_DLSYM(dl, node->get_node, "snd_card_def_get_node", err);
+	if (err)
+		goto done;
+	SND_DLSYM(dl, node->get_int, "snd_card_def_get_int", err);
+	if (err)
+		goto done;
+	SND_DLSYM(dl, node->get_str, "snd_card_def_get_str", err);
+
+done:
+	return err;
+}
+
+struct snd_node *snd_utils_get_dev_node(unsigned int card,
+		unsigned int device, int dev_type)
+{
+	struct snd_node *node;
+	int rc = 0;
+
+	node = calloc(1, sizeof(*node));
+	if (!node)
+		return NULL;
+
+	node->dl_hdl = dlopen("libsndcardparser.so", RTLD_NOW);
+	if (!node->dl_hdl) {
+		goto err_dl_open;
+	}
+
+	rc = snd_utils_resolve_symbols(node);
+	if (rc < 0)
+		goto err_resolve_symbols;
+
+	node->card_node = node->get_card(card);
+	if (!node->card_node)
+		goto err_resolve_symbols;
+
+	node->dev_node = node->get_node(node->card_node,
+					device, dev_type);
+	if (!node->dev_node)
+		goto err_get_node;
+
+	return node;
+
+err_get_node:
+	node->put_card(node->card_node);
+
+err_resolve_symbols:
+	dlclose(node->dl_hdl);
+
+err_dl_open:
+	free(node);
+	return NULL;
+}
diff --git a/snd_utils.h b/snd_utils.h
new file mode 100644
index 0000000..d00f7f2
--- /dev/null
+++ b/snd_utils.h
@@ -0,0 +1,72 @@
+/* snd_utils.h
+**
+** Copyright (c) 2019, The Linux Foundation. All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above
+**     copyright notice, this list of conditions and the following
+**     disclaimer in the documentation and/or other materials provided
+**     with the distribution.
+**   * Neither the name of The Linux Foundation nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+** ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+** BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+** BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+** OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+** IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**/
+
+#ifndef __SND_CARD_UTILS_H__
+#define __SND_CARD_UTILS_H__
+
+#include <dlfcn.h>
+
+struct snd_node {
+	void *card_node;
+	void *dev_node;
+	void *dl_hdl;
+
+	void* (*get_card) (unsigned int card);
+	void (*put_card) (void *card);
+	void* (*get_node) (void *card, unsigned int id,
+				int type);
+	int (*get_int) (void *node, const char *prop, int *val);
+	int (*get_str) (void *node, const char *prop, char **val);
+};
+
+enum {
+	NODE_PCM,
+	NODE_MIXER,
+	NODE_COMPRESS,
+};
+
+enum snd_node_type {
+	SND_NODE_TYPE_HW = 0,
+	SND_NODE_TYPE_PLUGIN,
+	SND_NODE_TYPE_INVALID,
+};
+
+struct snd_node *snd_utils_get_dev_node(unsigned int card,
+		unsigned int device, int dev_type);
+
+void snd_utils_put_dev_node(struct snd_node *node);
+
+enum snd_node_type snd_utils_get_node_type(struct snd_node *node);
+
+int snd_utils_get_int(struct snd_node *node, const char *prop, int *val);
+
+int snd_utils_get_str(struct snd_node *node, const char *prop, char **val);
+
+#endif /* end of __SND_CARD_UTILS_H__ */