audio: Initialize the radio voice session

This just allocates the structre and creates the RIL connection. This is
per audio_device structure to make sure we to not run into issues with
audioserver threading.

Change-Id: I42e1b7ae57579f39c5f76566ef5b67d4e2c13e3f
diff --git a/audio/voice.c b/audio/voice.c
new file mode 100644
index 0000000..57fcc60
--- /dev/null
+++ b/audio/voice.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2017 Christopher N. Hesse <raymanfx@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "audio_hw_voice"
+#define LOG_NDEBUG 0
+/*#define VERY_VERY_VERBOSE_LOGGING*/
+#ifdef VERY_VERY_VERBOSE_LOGGING
+#define ALOGVV ALOGV
+#else
+#define ALOGVV(a...) do { } while(0)
+#endif
+
+#include <stdlib.h>
+#include <pthread.h>
+
+#include "audio_hw.h"
+#include "voice.h"
+
+struct voice_session *voice_session_init(void)
+{
+    struct voice_session *session;
+    int ret;
+
+    session = calloc(1, sizeof(struct voice_session));
+    if (session == NULL) {
+        return NULL;
+    }
+
+    /* Do this as the last step so we do not have to close it on error */
+    ret = ril_open(&session->ril);
+    if (ret != 0) {
+        free(session);
+        return NULL;
+    }
+
+    return session;
+}
+
+void voice_session_deinit(struct voice_session *session)
+{
+    ril_close(&session->ril);
+    free(session);
+}