1 files changed, 149 insertions, 0 deletions
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;
+}