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From:   Abhay Maheta <abhay.maheshbhai.maheta@intel.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     Abhay Maheta <abhay.maheshbhai.maheta@intel.com>
Subject: [PATCH BlueZ v3 2/4] shared/mcp: Add initial code for handling MCP
Date:   Tue, 18 Oct 2022 10:08:29 +0530
Message-Id: <20221018043831.342821-3-abhay.maheshbhai.maheta@intel.com>
In-Reply-To: <20221018043831.342821-1-abhay.maheshbhai.maheta@intel.com>
References: <20221018043831.342821-1-abhay.maheshbhai.maheta@intel.com>
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This adds initial code for Media Control Profile for Client Role.
---
 Makefile.am      |    1 +
 src/shared/mcp.c | 1419 ++++++++++++++++++++++++++++++++++++++++++++++
 src/shared/mcp.h |   61 ++
 src/shared/mcs.h |   65 +++
 4 files changed, 1546 insertions(+)
 create mode 100644 src/shared/mcp.c
 create mode 100644 src/shared/mcp.h
 create mode 100644 src/shared/mcs.h

diff --git a/Makefile.am b/Makefile.am
index 27715c73d..23f6c1b98 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -231,6 +231,7 @@ shared_sources = src/shared/io.h src/shared/timeout.h \
 			src/shared/gap.h src/shared/gap.c \
 			src/shared/log.h src/shared/log.c \
 			src/shared/bap.h src/shared/bap.c src/shared/ascs.h \
+			src shared/mcs.h src/shared/mcp.h src/shared/mcp.c \
 			src/shared/vcp.c src/shared/vcp.h \
 			src/shared/lc3.h src/shared/tty.h
 
diff --git a/src/shared/mcp.c b/src/shared/mcp.c
new file mode 100644
index 000000000..b3726ebae
--- /dev/null
+++ b/src/shared/mcp.c
@@ -0,0 +1,1419 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2022  Intel Corporation. All rights reserved.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <inttypes.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "lib/bluetooth.h"
+#include "lib/uuid.h"
+#include "lib/hci.h"
+
+#include "src/shared/queue.h"
+#include "src/shared/util.h"
+#include "src/shared/timeout.h"
+#include "src/shared/att.h"
+#include "src/shared/gatt-db.h"
+#include "src/shared/gatt-server.h"
+#include "src/shared/gatt-client.h"
+#include "src/shared/mcp.h"
+#include "src/shared/mcs.h"
+
+#define DBG(_mcp, fmt, arg...) \
+	mcp_debug(_mcp, "%s:%s() " fmt, __FILE__, __func__, ## arg)
+
+struct bt_mcp_db {
+	struct gatt_db *db;
+	struct bt_mcs *mcs;
+};
+
+struct bt_mcp_pending {
+	unsigned int id;
+	struct bt_mcp *mcp;
+	bt_gatt_client_read_callback_t func;
+	void *user_data;
+};
+
+struct event_callback {
+	const struct bt_mcp_event_callback *cbs;
+	void *user_data;
+};
+
+struct bt_mcp_session_info {
+	uint8_t content_control_id;
+	uint32_t cp_op_supported;
+};
+
+struct bt_mcp {
+	int ref_count;
+	struct bt_gatt_client *client;
+	struct bt_mcp_db *ldb;
+	struct bt_mcp_db *rdb;
+	unsigned int mp_name_id;
+	unsigned int track_changed_id;
+	unsigned int track_title_id;
+	unsigned int track_duration_id;
+	unsigned int track_position_id;
+	unsigned int media_state_id;
+	unsigned int media_cp_id;
+	unsigned int media_cp_op_supported_id;
+
+	struct bt_mcp_session_info session;
+	struct event_callback *cb;
+
+	struct queue *pending;
+
+	bt_mcp_debug_func_t debug_func;
+	bt_mcp_destroy_func_t debug_destroy;
+	void *debug_data;
+	void *user_data;
+};
+
+struct bt_mcs {
+	struct bt_mcp_db *mdb;
+	struct gatt_db_attribute *service;
+	struct gatt_db_attribute *mp_name;
+	struct gatt_db_attribute *track_changed;
+	struct gatt_db_attribute *track_changed_ccc;
+	struct gatt_db_attribute *track_title;
+	struct gatt_db_attribute *track_duration;
+	struct gatt_db_attribute *track_position;
+	struct gatt_db_attribute *playback_speed;
+	struct gatt_db_attribute *seeking_speed;
+	struct gatt_db_attribute *play_order;
+	struct gatt_db_attribute *play_order_supported;
+	struct gatt_db_attribute *media_state;
+	struct gatt_db_attribute *media_state_ccc;
+	struct gatt_db_attribute *media_cp;
+	struct gatt_db_attribute *media_cp_ccc;
+	struct gatt_db_attribute *media_cp_op_supportd;
+	struct gatt_db_attribute *content_control_id;
+	struct gatt_db_attribute *content_control_id_ccc;
+};
+
+static struct queue *mcp_db;
+
+static void mcp_debug(struct bt_mcp *mcp, const char *format, ...)
+{
+	va_list ap;
+
+	if (!mcp || !format || !mcp->debug_func)
+		return;
+
+	va_start(ap, format);
+	util_debug_va(mcp->debug_func, mcp->debug_data, format, ap);
+	va_end(ap);
+}
+
+static bool mcp_db_match(const void *data, const void *match_data)
+{
+	const struct bt_mcp_db *mdb = data;
+	const struct gatt_db *db = match_data;
+
+	return (mdb->db == db);
+}
+
+static void mcp_db_free(void *data)
+{
+	struct bt_mcp_db *bdb = data;
+
+	if (!bdb)
+		return;
+
+	gatt_db_unref(bdb->db);
+
+	free(bdb->mcs);
+	free(bdb);
+}
+
+static void mcp_free(void *data)
+{
+	struct bt_mcp *mcp = data;
+
+	DBG(mcp, "");
+
+	bt_mcp_detach(mcp);
+
+	mcp_db_free(mcp->rdb);
+
+	queue_destroy(mcp->pending, NULL);
+
+	free(mcp);
+}
+
+struct bt_mcp *bt_mcp_ref(struct bt_mcp *mcp)
+{
+	if (!mcp)
+		return NULL;
+
+	__sync_fetch_and_add(&mcp->ref_count, 1);
+
+	return mcp;
+}
+
+void bt_mcp_unref(struct bt_mcp *mcp)
+{
+	if (!mcp)
+		return;
+
+	if (__sync_sub_and_fetch(&mcp->ref_count, 1))
+		return;
+
+	mcp_free(mcp);
+}
+
+bool bt_mcp_set_user_data(struct bt_mcp *mcp, void *user_data)
+{
+	if (!mcp)
+		return false;
+
+	mcp->user_data = user_data;
+
+	return true;
+}
+
+void *bt_mcp_get_user_data(struct bt_mcp *mcp)
+{
+	if (!mcp)
+		return NULL;
+
+	return mcp->user_data;
+}
+
+bool bt_mcp_set_debug(struct bt_mcp *mcp, bt_mcp_debug_func_t func,
+			void *user_data, bt_mcp_destroy_func_t destroy)
+{
+	if (!mcp)
+		return false;
+
+	if (mcp->debug_destroy)
+		mcp->debug_destroy(mcp->debug_data);
+
+	mcp->debug_func = func;
+	mcp->debug_destroy = destroy;
+	mcp->debug_data = user_data;
+
+	return true;
+}
+
+static void mcs_mp_name_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	char mp_name[] = "";
+	struct iovec iov;
+
+	iov.iov_base = mp_name;
+	iov.iov_len = sizeof(mp_name);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_track_title_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	char track_title[] = "";
+	struct iovec iov;
+
+	iov.iov_base = track_title;
+	iov.iov_len = 0;
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_track_duration_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	int32_t track_duration = 0xFFFFFFFF;
+	struct iovec iov;
+
+	iov.iov_base = &track_duration;
+	iov.iov_len = sizeof(track_duration);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_track_position_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	int32_t track_position = 0xFFFFFFFF;
+	struct iovec iov;
+
+	iov.iov_base = &track_position;
+	iov.iov_len = sizeof(track_position);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_track_position_write(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				const uint8_t *value, size_t len,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	gatt_db_attribute_write_result(attrib, id,
+			BT_ATT_ERROR_INSUFFICIENT_RESOURCES);
+}
+
+static void mcs_playback_speed_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	int8_t playback_speed = 0x00;
+	struct iovec iov;
+
+	iov.iov_base = &playback_speed;
+	iov.iov_len = sizeof(playback_speed);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_playback_speed_write(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				const uint8_t *value, size_t len,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	gatt_db_attribute_write_result(attrib, id,
+				BT_ATT_ERROR_INSUFFICIENT_RESOURCES);
+}
+
+static void mcs_seeking_speed_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	int8_t seeking_speed = 0x00;
+	struct iovec iov;
+
+	iov.iov_base = &seeking_speed;
+	iov.iov_len = sizeof(seeking_speed);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_playing_order_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	uint8_t playing_order = 0x01;
+	struct iovec iov;
+
+	iov.iov_base = &playing_order;
+	iov.iov_len = sizeof(playing_order);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_playing_order_write(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				const uint8_t *value, size_t len,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	gatt_db_attribute_write_result(attrib, id,
+				BT_ATT_ERROR_INSUFFICIENT_RESOURCES);
+}
+
+static void mcs_playing_order_supported_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	uint16_t playing_order_supported = 0x01;
+	struct iovec iov;
+
+	iov.iov_base = &playing_order_supported;
+	iov.iov_len = sizeof(playing_order_supported);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_media_state_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	uint8_t media_state = 0x00;
+	struct iovec iov;
+
+	iov.iov_base = &media_state;
+	iov.iov_len = sizeof(media_state);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_media_cp_write(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				const uint8_t *value, size_t len,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	gatt_db_attribute_write_result(attrib, id,
+				BT_ATT_ERROR_INSUFFICIENT_RESOURCES);
+}
+
+static void mcs_media_cp_op_supported_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	uint32_t cp_op_supported = 0x00000000;
+	struct iovec iov;
+
+	iov.iov_base = &cp_op_supported;
+	iov.iov_len = sizeof(cp_op_supported);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static void mcs_media_content_control_id_read(struct gatt_db_attribute *attrib,
+				unsigned int id, uint16_t offset,
+				uint8_t opcode, struct bt_att *att,
+				void *user_data)
+{
+	uint8_t content_control_id = 0x00;
+	struct iovec iov;
+
+	iov.iov_base = &content_control_id;
+	iov.iov_len = sizeof(content_control_id);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+							iov.iov_len);
+}
+
+static struct bt_mcs *mcs_new(struct gatt_db *db)
+{
+	struct bt_mcs *mcs;
+	bt_uuid_t uuid;
+
+	if (!db)
+		return NULL;
+
+	mcs = new0(struct bt_mcs, 1);
+
+	/* Populate DB with MCS attributes */
+	bt_uuid16_create(&uuid, GMCS_UUID);
+	mcs->service = gatt_db_add_service(db, &uuid, true, 31);
+
+	bt_uuid16_create(&uuid, MEDIA_PLAYER_NAME_CHRC_UUID);
+	mcs->mp_name = gatt_db_service_add_characteristic(mcs->service, &uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					mcs_mp_name_read, NULL,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_TRACK_CHNGD_CHRC_UUID);
+	mcs->track_changed = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_NONE,
+					BT_GATT_CHRC_PROP_NOTIFY,
+					NULL, NULL,
+					mcs);
+
+	mcs->track_changed_ccc = gatt_db_service_add_ccc(mcs->service,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+	bt_uuid16_create(&uuid, MEDIA_TRACK_TITLE_CHRC_UUID);
+	mcs->track_title = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					mcs_track_title_read, NULL,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_TRACK_DURATION_CHRC_UUID);
+	mcs->track_duration = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					mcs_track_duration_read, NULL,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_TRACK_POSTION_CHRC_UUID);
+	mcs->track_position = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE,
+					BT_GATT_CHRC_PROP_READ |
+					BT_GATT_CHRC_PROP_WRITE |
+					BT_GATT_CHRC_PROP_WRITE_WITHOUT_RESP,
+					mcs_track_position_read,
+					mcs_track_position_write,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_PLAYBACK_SPEED_CHRC_UUID);
+	mcs->playback_speed = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE,
+					BT_GATT_CHRC_PROP_READ |
+					BT_GATT_CHRC_PROP_WRITE |
+					BT_GATT_CHRC_PROP_WRITE_WITHOUT_RESP,
+					mcs_playback_speed_read,
+					mcs_playback_speed_write,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_SEEKING_SPEED_CHRC_UUID);
+	mcs->seeking_speed = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					mcs_seeking_speed_read, NULL,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_PLAYING_ORDER_CHRC_UUID);
+	mcs->play_order = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE,
+					BT_GATT_CHRC_PROP_READ |
+					BT_GATT_CHRC_PROP_WRITE |
+					BT_GATT_CHRC_PROP_WRITE_WITHOUT_RESP,
+					mcs_playing_order_read,
+					mcs_playing_order_write,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_PLAY_ORDER_SUPPRTD_CHRC_UUID);
+	mcs->play_order_supported = gatt_db_service_add_characteristic(
+					mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					mcs_playing_order_supported_read, NULL,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_STATE_CHRC_UUID);
+	mcs->media_state = gatt_db_service_add_characteristic(mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ |
+					BT_GATT_CHRC_PROP_NOTIFY,
+					mcs_media_state_read, NULL,
+					mcs);
+
+	mcs->media_state_ccc = gatt_db_service_add_ccc(mcs->service,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+	bt_uuid16_create(&uuid, MEDIA_CP_CHRC_UUID);
+	mcs->media_cp = gatt_db_service_add_characteristic(mcs->service, &uuid,
+					BT_ATT_PERM_WRITE,
+					BT_GATT_CHRC_PROP_WRITE |
+					BT_GATT_CHRC_PROP_NOTIFY |
+					BT_GATT_CHRC_PROP_WRITE_WITHOUT_RESP,
+					NULL, mcs_media_cp_write,
+					mcs);
+
+	mcs->media_cp_ccc = gatt_db_service_add_ccc(mcs->service,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+	bt_uuid16_create(&uuid, MEDIA_CP_OP_SUPPORTED_CHRC_UUID);
+	mcs->media_cp_op_supportd = gatt_db_service_add_characteristic(
+					mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ,
+					mcs_media_cp_op_supported_read, NULL,
+					mcs);
+
+	bt_uuid16_create(&uuid, MEDIA_CONTENT_CONTROL_ID_CHRC_UUID);
+	mcs->content_control_id = gatt_db_service_add_characteristic(
+					mcs->service,
+					&uuid,
+					BT_ATT_PERM_READ,
+					BT_GATT_CHRC_PROP_READ |
+					BT_GATT_CHRC_PROP_NOTIFY,
+					mcs_media_content_control_id_read,
+					NULL,
+					mcs);
+
+	mcs->content_control_id_ccc = gatt_db_service_add_ccc(mcs->service,
+					BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+	gatt_db_service_set_active(mcs->service, false);
+
+	return mcs;
+}
+
+static struct bt_mcs *mcp_get_mcs(struct bt_mcp *mcp)
+{
+	if (!mcp)
+		return NULL;
+
+	if (mcp->rdb->mcs)
+		return mcp->rdb->mcs;
+
+	mcp->rdb->mcs = new0(struct bt_mcs, 1);
+	mcp->rdb->mcs->mdb = mcp->rdb;
+
+	return mcp->rdb->mcs;
+}
+
+static unsigned int mcp_send(struct bt_mcp *mcp, uint8_t operation)
+{
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+	int ret;
+	uint16_t handle;
+
+	DBG(mcp, "mcs %p", mcs);
+
+	if (!mcp->client)
+		return -1;
+
+	if (!gatt_db_attribute_get_char_data(mcs->media_cp, NULL, &handle,
+					NULL, NULL, NULL))
+		return -1;
+
+	ret = bt_gatt_client_write_without_response(mcp->client, handle, false,
+					&operation, sizeof(uint8_t));
+	if (!ret)
+		return -1;
+
+	return 0;
+}
+
+unsigned int bt_mcp_play(struct bt_mcp *mcp)
+{
+	if (!(mcp->session.cp_op_supported & BT_MCS_CMD_PLAY_SUPPORTED))
+		return -ENOTSUP;
+
+	DBG(mcp, "mcp %p", mcp);
+
+	return mcp_send(mcp, BT_MCS_CMD_PLAY);
+}
+
+unsigned int bt_mcp_pause(struct bt_mcp *mcp)
+{
+	if (!(mcp->session.cp_op_supported & BT_MCS_CMD_PAUSE_SUPPORTED))
+		return -ENOTSUP;
+
+	DBG(mcp, "mcp %p", mcp);
+
+	return mcp_send(mcp, BT_MCS_CMD_PAUSE);
+}
+
+unsigned int bt_mcp_stop(struct bt_mcp *mcp)
+{
+	if (!(mcp->session.cp_op_supported & BT_MCS_CMD_STOP_SUPPORTED))
+		return -ENOTSUP;
+
+	DBG(mcp, "mcp %p", mcp);
+
+	return mcp_send(mcp, BT_MCS_CMD_STOP);
+}
+
+static void mcp_mp_set_player_name(struct bt_mcp *mcp, const uint8_t *value,
+					uint16_t length)
+{
+	struct event_callback *cb = mcp->cb;
+
+	if (cb && cb->cbs && cb->cbs->player_name)
+		cb->cbs->player_name(mcp, value, length);
+}
+
+static void mcp_mp_set_track_title(struct bt_mcp *mcp, const uint8_t *value,
+					uint16_t length)
+{
+	struct event_callback *cb = mcp->cb;
+
+	if (cb && cb->cbs && cb->cbs->track_title)
+		cb->cbs->track_title(mcp, value, length);
+}
+
+static void mcp_mp_set_title_duration(struct bt_mcp *mcp, int32_t duration)
+{
+	struct event_callback *cb = mcp->cb;
+
+	DBG(mcp, "Track Duration 0x%08x", duration);
+
+	if (cb && cb->cbs && cb->cbs->track_duration)
+		cb->cbs->track_duration(mcp, duration);
+}
+
+static void mcp_mp_set_title_position(struct bt_mcp *mcp, int32_t position)
+{
+	struct event_callback *cb = mcp->cb;
+
+	DBG(mcp, "Track Position 0x%08x", position);
+
+	if (cb && cb->cbs && cb->cbs->track_position)
+		cb->cbs->track_position(mcp, position);
+}
+
+static void mcp_mp_set_media_state(struct bt_mcp *mcp, uint8_t state)
+{
+	struct event_callback *cb = mcp->cb;
+
+	DBG(mcp, "Media State 0x%02x", state);
+
+	if (cb && cb->cbs && cb->cbs->media_state)
+		cb->cbs->media_state(mcp, state);
+}
+
+static void read_media_player_name(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (!success) {
+		DBG(mcp, "Unable to read media player name: error 0x%02x",
+				att_ecode);
+		return;
+	}
+
+	if (!length)
+		return;
+
+	mcp_mp_set_player_name(mcp, value, length);
+}
+
+static void read_track_title(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (!success) {
+		DBG(mcp, "Unable to read track title: error 0x%02x",
+					att_ecode);
+		return;
+	}
+
+	if (!length)
+		return;
+
+	mcp_mp_set_track_title(mcp, value, length);
+}
+
+static void read_track_duration(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+	int32_t duration;
+
+	if (!success) {
+		DBG(mcp, "Unable to read track duration: error 0x%02x",
+					att_ecode);
+		return;
+	}
+
+	if (length != sizeof(duration))
+		DBG(mcp, "Wrong length received Length : %u", length);
+
+	memcpy(&duration, value, length);
+	mcp_mp_set_title_duration(mcp, duration);
+}
+
+static void read_track_position(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+	int32_t position;
+
+	if (!success) {
+		DBG(mcp, "Unable to read track position: error 0x%02x",
+					att_ecode);
+		return;
+	}
+
+	if (length != sizeof(position))
+		DBG(mcp, "Wrong length received Length : %u", length);
+
+	memcpy(&position, value, length);
+	mcp_mp_set_title_position(mcp, position);
+}
+
+static void read_media_state(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (!success) {
+		DBG(mcp, "Unable to read media state: error 0x%02x",
+					att_ecode);
+		return;
+	}
+
+	if (length != sizeof(uint8_t))
+		DBG(mcp, "Wrong length received Length : %u", length);
+
+	mcp_mp_set_media_state(mcp, *value);
+}
+
+static void read_media_cp_op_supported(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (!success) {
+		DBG(mcp, "Unable to read media CP OP supported: error 0x%02x",
+					att_ecode);
+		return;
+	}
+
+	if (length != sizeof(uint32_t))
+		DBG(mcp, "Wrong length received Length : %u", length);
+
+	memcpy(&mcp->session.cp_op_supported, value, sizeof(uint32_t));
+	DBG(mcp, "Media Control Point Opcodes Supported 0x%08x",
+			mcp->session.cp_op_supported);
+}
+
+static void read_content_control_id(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (!success) {
+		DBG(mcp, "Unable to read content control id: error 0x%02x",
+					att_ecode);
+		return;
+	}
+
+	if (length != sizeof(uint8_t))
+		DBG(mcp, "Wrong length received Length : %u", length);
+
+	DBG(mcp, "Content Control ID 0x%02x", *value);
+}
+
+static void mcp_pending_destroy(void *data)
+{
+	struct bt_mcp_pending *pending = data;
+	struct bt_mcp *mcp = pending->mcp;
+
+	queue_remove_if(mcp->pending, NULL, pending);
+}
+
+static void mcp_pending_complete(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_mcp_pending *pending = user_data;
+
+	if (pending->func)
+		pending->func(success, att_ecode, value, length,
+						pending->user_data);
+}
+
+static void mcp_read_value(struct bt_mcp *mcp, uint16_t value_handle,
+				bt_gatt_client_read_callback_t func,
+				void *user_data)
+{
+	struct bt_mcp_pending *pending;
+
+	pending = new0(struct bt_mcp_pending, 1);
+	pending->mcp = mcp;
+	pending->func = func;
+	pending->user_data = user_data;
+
+	pending->id = bt_gatt_client_read_value(mcp->client, value_handle,
+						mcp_pending_complete, pending,
+						mcp_pending_destroy);
+	if (!pending->id) {
+		DBG(mcp, "Unable to send Read request");
+		free(pending);
+		return;
+	}
+
+	queue_push_tail(mcp->pending, pending);
+}
+
+static void mcp_mp_name_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Player Name notification failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_mp_name_notify(uint16_t value_handle, const uint8_t *value,
+					uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (!length)
+		return;
+
+	mcp_mp_set_player_name(mcp, value, length);
+}
+
+static void mcp_track_changed_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Track Changed notification failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_track_changed_notify(uint16_t value_handle,
+			const uint8_t *value, uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+	struct event_callback *cb = mcp->cb;
+
+	DBG(mcp, "Track Changed");
+
+	if (cb && cb->cbs && cb->cbs->track_changed)
+		cb->cbs->track_changed(mcp);
+}
+
+static void mcp_track_title_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Track Title notification failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_track_title_notify(uint16_t value_handle,
+			const uint8_t *value, uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	mcp_mp_set_track_title(mcp, value, length);
+}
+
+static void mcp_track_duration_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Track Duration notification failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_track_duration_notify(uint16_t value_handle,
+			const uint8_t *value, uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+	int32_t duration;
+
+	memcpy(&duration, value, sizeof(int32_t));
+	mcp_mp_set_title_duration(mcp, duration);
+}
+
+static void mcp_track_position_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Track Position notification failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_track_position_notify(uint16_t value_handle,
+		const uint8_t *value, uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+	int32_t position;
+
+	memcpy(&position, value, sizeof(int32_t));
+	mcp_mp_set_title_position(mcp, position);
+}
+
+static void mcp_media_state_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Media State notification failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_media_state_notify(uint16_t value_handle,
+			const uint8_t *value, uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	mcp_mp_set_media_state(mcp, *value);
+}
+
+static void mcp_media_cp_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Media CP notification failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_media_cp_notify(uint16_t value_handle, const uint8_t *value,
+					uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	DBG(mcp, "Media CP Notification");
+}
+
+static void mcp_media_cp_op_supported_register(uint16_t att_ecode,
+					void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	if (att_ecode)
+		DBG(mcp, "Media Media CP OP Supported notify failed: 0x%04x",
+					att_ecode);
+}
+
+static void mcp_media_cp_op_supported_notify(uint16_t value_handle,
+			const uint8_t *value, uint16_t length, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+
+	memcpy(&mcp->session.cp_op_supported, value, sizeof(uint32_t));
+	DBG(mcp, "Media CP Opcodes Supported Notification 0x%08x",
+			mcp->session.cp_op_supported);
+}
+
+static void bt_mcp_mp_name_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->mp_name, NULL, &value_handle,
+						NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Media Player handle 0x%04x", value_handle);
+
+	mcp_read_value(mcp, value_handle, read_media_player_name, mcp);
+
+	mcp->mp_name_id = bt_gatt_client_register_notify(mcp->client,
+				value_handle, mcp_mp_name_register,
+				mcp_mp_name_notify, mcp, NULL);
+}
+
+static void bt_mcp_track_changed_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->track_changed, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Track Changed handle 0x%04x", value_handle);
+
+	mcp->track_changed_id = bt_gatt_client_register_notify(mcp->client,
+				value_handle, mcp_track_changed_register,
+				mcp_track_changed_notify, mcp, NULL);
+}
+
+static void bt_mcp_track_title_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->track_title, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Track Title handle 0x%04x", value_handle);
+
+	mcp_read_value(mcp, value_handle, read_track_title, mcp);
+
+	mcp->track_title_id = bt_gatt_client_register_notify(mcp->client,
+				value_handle, mcp_track_title_register,
+				mcp_track_title_notify, mcp, NULL);
+}
+
+static void bt_mcp_track_duration_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->track_duration, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Track Duration handle 0x%04x", value_handle);
+
+	mcp_read_value(mcp, value_handle, read_track_duration, mcp);
+
+	mcp->track_duration_id = bt_gatt_client_register_notify(mcp->client,
+				value_handle, mcp_track_duration_register,
+				mcp_track_duration_notify, mcp, NULL);
+}
+
+static void bt_mcp_track_position_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->track_position, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Track Position handle 0x%04x", value_handle);
+
+	mcp_read_value(mcp, value_handle, read_track_position, mcp);
+
+	mcp->track_position_id = bt_gatt_client_register_notify(mcp->client,
+				value_handle, mcp_track_position_register,
+				mcp_track_position_notify, mcp, NULL);
+}
+
+static void bt_mcp_media_state_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->media_state, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Media State handle 0x%04x", value_handle);
+
+	mcp_read_value(mcp, value_handle, read_media_state, mcp);
+
+	mcp->media_state_id = bt_gatt_client_register_notify(mcp->client,
+					value_handle, mcp_media_state_register,
+					mcp_media_state_notify, mcp, NULL);
+}
+
+static void bt_mcp_media_cp_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->media_cp, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Media Control Point handle 0x%04x", value_handle);
+
+	mcp->media_cp_id = bt_gatt_client_register_notify(mcp->client,
+					value_handle, mcp_media_cp_register,
+					mcp_media_cp_notify, mcp, NULL);
+}
+
+static void bt_mcp_media_cp_op_supported_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->media_cp_op_supportd, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Media Control Point Opcodes Supported handle 0x%04x",
+			value_handle);
+
+	mcp_read_value(mcp, value_handle, read_media_cp_op_supported, mcp);
+
+	mcp->media_cp_op_supported_id = bt_gatt_client_register_notify(
+		mcp->client, value_handle, mcp_media_cp_op_supported_register,
+		mcp_media_cp_op_supported_notify, mcp, NULL);
+}
+
+static void bt_mcp_content_control_id_supported_attach(struct bt_mcp *mcp)
+{
+	uint16_t value_handle;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	if (!gatt_db_attribute_get_char_data(mcs->content_control_id, NULL,
+				&value_handle, NULL, NULL, NULL))
+		return;
+
+	DBG(mcp, "Media Content Control id Supported handle 0x%04x",
+				value_handle);
+	mcp_read_value(mcp, value_handle, read_content_control_id, mcp);
+}
+
+static void foreach_mcs_char(struct gatt_db_attribute *attr, void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+	uint16_t value_handle;
+	bt_uuid_t uuid, uuid_mp_name, uuid_track_changed, uuid_track_title,
+		uuid_track_duration, uuid_track_position, uuid_media_state,
+		uuid_media_cp, uuid_media_cp_op_supported,
+		uuid_content_control_id;
+	struct bt_mcs *mcs;
+
+	if (!gatt_db_attribute_get_char_data(attr, NULL, &value_handle,
+						NULL, NULL, &uuid))
+		return;
+
+	bt_uuid16_create(&uuid_mp_name, MEDIA_PLAYER_NAME_CHRC_UUID);
+	bt_uuid16_create(&uuid_track_changed, MEDIA_TRACK_CHNGD_CHRC_UUID);
+	bt_uuid16_create(&uuid_track_title, MEDIA_TRACK_TITLE_CHRC_UUID);
+	bt_uuid16_create(&uuid_track_duration, MEDIA_TRACK_DURATION_CHRC_UUID);
+	bt_uuid16_create(&uuid_track_position, MEDIA_TRACK_POSTION_CHRC_UUID);
+	bt_uuid16_create(&uuid_media_state, MEDIA_STATE_CHRC_UUID);
+	bt_uuid16_create(&uuid_media_cp, MEDIA_CP_CHRC_UUID);
+	bt_uuid16_create(&uuid_media_cp_op_supported,
+					MEDIA_CP_OP_SUPPORTED_CHRC_UUID);
+	bt_uuid16_create(&uuid_content_control_id,
+					MEDIA_CONTENT_CONTROL_ID_CHRC_UUID);
+
+	if (!bt_uuid_cmp(&uuid, &uuid_mp_name)) {
+		DBG(mcp, "Media Player Name found: handle 0x%04x",
+					value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->mp_name)
+			return;
+
+		mcs->mp_name = attr;
+		bt_mcp_mp_name_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_track_changed)) {
+		DBG(mcp, "Track Changed found: handle 0x%04x", value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->track_changed)
+			return;
+
+		mcs->track_changed = attr;
+		bt_mcp_track_changed_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_track_title)) {
+		DBG(mcp, "Track Title found: handle 0x%04x", value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->track_title)
+			return;
+
+		mcs->track_title = attr;
+		bt_mcp_track_title_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_track_duration)) {
+		DBG(mcp, "Track Duration found: handle 0x%04x", value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->track_duration)
+			return;
+
+		mcs->track_duration = attr;
+		bt_mcp_track_duration_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_track_position)) {
+		DBG(mcp, "Track Position found: handle 0x%04x", value_handle);
+
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->track_position)
+			return;
+
+		mcs->track_position = attr;
+		bt_mcp_track_position_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_media_state)) {
+		DBG(mcp, "Media State found: handle 0x%04x", value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->media_state)
+			return;
+
+		mcs->media_state = attr;
+		bt_mcp_media_state_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_media_cp)) {
+		DBG(mcp, "Media Control Point found: handle 0x%04x",
+					value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->media_cp)
+			return;
+
+		mcs->media_cp = attr;
+		bt_mcp_media_cp_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_media_cp_op_supported)) {
+		DBG(mcp, "Media CP Opcodes Supported found: handle 0x%04x",
+					value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->media_cp_op_supportd)
+			return;
+
+		mcs->media_cp_op_supportd = attr;
+		bt_mcp_media_cp_op_supported_attach(mcp);
+	}
+
+	if (!bt_uuid_cmp(&uuid, &uuid_content_control_id)) {
+		DBG(mcp, "Content Control ID found: handle 0x%04x",
+					value_handle);
+
+		mcs = mcp_get_mcs(mcp);
+		if (!mcs || mcs->content_control_id)
+			return;
+
+		mcs->content_control_id = attr;
+		bt_mcp_content_control_id_supported_attach(mcp);
+	}
+}
+
+void bt_mcp_set_event_callbacks(struct bt_mcp *mcp,
+				const struct bt_mcp_event_callback *cbs,
+				void *user_data)
+{
+	struct event_callback *cb;
+
+	if (mcp->cb)
+		free(mcp->cb);
+
+	cb = new0(struct event_callback, 1);
+	cb->cbs = cbs;
+	cb->user_data = user_data;
+
+	mcp->cb = cb;
+}
+
+static void foreach_mcs_service(struct gatt_db_attribute *attr,
+						void *user_data)
+{
+	struct bt_mcp *mcp = user_data;
+	struct bt_mcs *mcs = mcp_get_mcs(mcp);
+
+	DBG(mcp, "");
+
+	mcs->service = attr;
+
+	gatt_db_service_foreach_char(attr, foreach_mcs_char, mcp);
+}
+
+static struct bt_mcp_db *mcp_db_new(struct gatt_db *db)
+{
+	struct bt_mcp_db *mdb;
+
+	if (!db)
+		return NULL;
+
+	mdb = new0(struct bt_mcp_db, 1);
+	mdb->db = gatt_db_ref(db);
+
+	if (!mcp_db)
+		mcp_db = queue_new();
+
+	queue_push_tail(mcp_db, mdb);
+
+	mdb->mcs = mcs_new(db);
+	return mdb;
+}
+
+static struct bt_mcp_db *mcp_get_db(struct gatt_db *db)
+{
+	struct bt_mcp_db *mdb;
+
+	mdb = queue_find(mcp_db, mcp_db_match, db);
+	if (mdb)
+		return mdb;
+
+	return mcp_db_new(db);
+}
+
+struct bt_mcp *bt_mcp_new(struct gatt_db *ldb, struct gatt_db *rdb)
+{
+	struct bt_mcp *mcp;
+	struct bt_mcp_db *mdb;
+
+	if (!ldb)
+		return NULL;
+
+	mdb = mcp_get_db(ldb);
+	if (!mdb)
+		return NULL;
+
+	mcp = new0(struct bt_mcp, 1);
+	mcp->ldb = mdb;
+	mcp->pending = queue_new();
+
+	if (!rdb)
+		goto done;
+
+	mdb = new0(struct bt_mcp_db, 1);
+	mdb->db = gatt_db_ref(rdb);
+
+	mcp->rdb = mdb;
+
+done:
+	bt_mcp_ref(mcp);
+
+	return mcp;
+}
+
+void bt_mcp_register(struct gatt_db *db)
+{
+	mcp_db_new(db);
+}
+
+bool bt_mcp_attach(struct bt_mcp *mcp, struct bt_gatt_client *client)
+{
+	bt_uuid_t uuid;
+
+	DBG(mcp, "mcp %p", mcp);
+
+	mcp->client = bt_gatt_client_clone(client);
+	if (!mcp->client)
+		return false;
+
+	if (mcp->rdb->mcs) {
+		bt_mcp_mp_name_attach(mcp);
+		bt_mcp_track_changed_attach(mcp);
+		bt_mcp_track_title_attach(mcp);
+		bt_mcp_track_duration_attach(mcp);
+		bt_mcp_track_position_attach(mcp);
+		bt_mcp_media_state_attach(mcp);
+		bt_mcp_media_cp_attach(mcp);
+		bt_mcp_media_cp_op_supported_attach(mcp);
+		bt_mcp_content_control_id_supported_attach(mcp);
+
+		return true;
+	}
+
+	bt_uuid16_create(&uuid, GMCS_UUID);
+	gatt_db_foreach_service(mcp->rdb->db, &uuid, foreach_mcs_service, mcp);
+
+	return true;
+}
+
+void bt_mcp_detach(struct bt_mcp *mcp)
+{
+	DBG(mcp, "%p", mcp);
+
+	bt_gatt_client_unref(mcp->client);
+	mcp->client = NULL;
+}
diff --git a/src/shared/mcp.h b/src/shared/mcp.h
new file mode 100644
index 000000000..a2cd6fc45
--- /dev/null
+++ b/src/shared/mcp.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2020  Intel Corporation. All rights reserved.
+ *
+ */
+
+#include <stdbool.h>
+#include <inttypes.h>
+
+#ifndef __packed
+#define __packed __attribute__((packed))
+#endif
+
+struct bt_mcp;
+struct bt_mcp_db;
+struct bt_mcp_session_info;
+
+typedef void (*bt_mcp_debug_func_t)(const char *str, void *user_data);
+typedef void (*bt_mcp_destroy_func_t)(void *user_data);
+
+struct bt_mcp_event_callback {
+	void (*player_name)(struct bt_mcp *mcp,  const uint8_t *value,
+					uint16_t length);
+	void (*track_changed)(struct bt_mcp *mcp);
+	void (*track_title)(struct bt_mcp *mcp, const uint8_t *value,
+					uint16_t length);
+	void (*track_duration)(struct bt_mcp *mcp, int32_t duration);
+	void (*track_position)(struct bt_mcp *mcp, int32_t position);
+	void (*playback_speed)(struct bt_mcp *mcp, int8_t speed);
+	void (*seeking_speed)(struct bt_mcp *mcp, int8_t speed);
+	void (*play_order)(struct bt_mcp *mcp, uint8_t order);
+	void (*play_order_supported)(struct bt_mcp *mcp,
+					uint16_t order_supported);
+	void (*media_state)(struct bt_mcp *mcp, uint8_t state);
+	void (*content_control_id)(struct bt_mcp *mcp, uint8_t cc_id);
+};
+
+void bt_mcp_set_event_callbacks(struct bt_mcp *mcp,
+				const struct bt_mcp_event_callback *cbs,
+				void *user_data);
+
+bool bt_mcp_set_debug(struct bt_mcp *mcp, bt_mcp_debug_func_t cb,
+			void *user_data, bt_mcp_destroy_func_t destroy);
+
+void bt_mcp_register(struct gatt_db *db);
+bool bt_mcp_attach(struct bt_mcp *mcp, struct bt_gatt_client *client);
+void bt_mcp_detach(struct bt_mcp *mcp);
+
+struct bt_mcp *bt_mcp_new(struct gatt_db *ldb, struct gatt_db *rdb);
+struct bt_mcp *bt_mcp_ref(struct bt_mcp *mcp);
+void bt_mcp_unref(struct bt_mcp *mcp);
+
+bool bt_mcp_set_user_data(struct bt_mcp *mcp, void *user_data);
+void *bt_mcp_get_user_data(struct bt_mcp *mcp);
+
+unsigned int bt_mcp_play(struct bt_mcp *mcp);
+unsigned int bt_mcp_pause(struct bt_mcp *mcp);
+unsigned int bt_mcp_stop(struct bt_mcp *mcp);
diff --git a/src/shared/mcs.h b/src/shared/mcs.h
new file mode 100644
index 000000000..09b3bffe8
--- /dev/null
+++ b/src/shared/mcs.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2020  Intel Corporation. All rights reserved.
+ *
+ */
+
+/* MCP Media State */
+#define BT_MCS_STATUS_INACTIVE	0x00
+#define BT_MCS_STATUS_PLAYING	0x01
+#define BT_MCS_STATUS_PAUSED	0x02
+#define BT_MCS_STATUS_SEEKING	0x03
+
+/* MCP Control Point Opcodes */
+#define BT_MCS_CMD_PLAY			    0x01
+#define BT_MCS_CMD_PAUSE		    0x02
+#define BT_MCS_CMD_FAST_REWIND	    0x03
+#define BT_MCS_CMD_FAST_FORWARD	    0x04
+#define BT_MCS_CMD_STOP			    0x05
+
+#define BT_MCS_CMD_MOVE_RELATIVE    0x10
+
+#define BT_MCS_CMD_PREV_SEGMENT     0x20
+#define BT_MCS_CMD_NEXT_SEGMENT     0x21
+#define BT_MCS_CMD_FIRST_SEGMENT    0x22
+#define BT_MCS_CMD_LAST_SEGMENT     0x23
+#define BT_MCS_CMD_GOTO_SEGMENT     0x24
+
+#define BT_MCS_CMD_PREV_TRACK       0x30
+#define BT_MCS_CMD_NEXT_TRACK       0x31
+#define BT_MCS_CMD_FIRST_TRACK      0x32
+#define BT_MCS_CMD_LAST_TRACK       0x33
+#define BT_MCS_CMD_GOTO_TRACK       0x34
+
+#define BT_MCS_CMD_PREV_GROUP       0x40
+#define BT_MCS_CMD_NEXT_GROUP       0x41
+#define BT_MCS_CMD_FIRST_GROUP      0x42
+#define BT_MCS_CMD_LAST_GROUP       0x43
+#define BT_MCS_CMD_GOTO_GROUP       0x44
+
+
+/* MCP Control Point Opcodes Supported */
+#define BT_MCS_CMD_PLAY_SUPPORTED		0x00000001
+#define BT_MCS_CMD_PAUSE_SUPPORTED		0x00000002
+#define BT_MCS_CMD_FAST_REWIND_SUPPORTED	0x00000004
+#define BT_MCS_CMD_FAST_FORWARD_SUPPORTED	0x00000008
+#define BT_MCS_CMD_STOP_SUPPORTED		0x00000010
+#define BT_MCS_CMD_MOVE_RELATIVE_SUPPORTED	0x00000020
+#define BT_MCS_CMD_PREV_SEGMENT_SUPPORTED	0x00000040
+#define BT_MCS_CMD_NEXT_SEGMENT_SUPPORTED	0x00000080
+#define BT_MCS_CMD_FIRST_SEGMENT_SUPPORTED	0x00000100
+#define BT_MCS_CMD_LAST_SEGMENT_SUPPORTED	0x00000200
+#define BT_MCS_CMD_GOTO_SEGMENT_SUPPORTED	0x00000400
+#define BT_MCS_CMD_PREV_TRACK_SUPPORTED		0x00000800
+#define BT_MCS_CMD_NEXT_TRACK_SUPPORTED		0x00001000
+#define BT_MCS_CMD_FIRST_TRACK_SUPPORTED	0x00002000
+#define BT_MCS_CMD_LAST_TRACK_SUPPORTED		0x00004000
+#define BT_MCS_CMD_GOTO_TRACK_SUPPORTED		0x00008000
+#define BT_MCS_CMD_PREV_GROUP_SUPPORTED		0x00010000
+#define BT_MCS_CMD_NEXT_GROUP_SUPPORTED		0x00020000
+#define BT_MCS_CMD_FIRST_GROUP_SUPPORTED	0x00040000
+#define BT_MCS_CMD_LAST_GROUP_SUPPORTED		0x00080000
+#define BT_MCS_CMD_GOTO_GROUP_SUPPORTED		0x00100000
-- 
2.25.1