diff mbox series

[BlueZ,v2,2/4] src/shared/micp.c: To implement MICP profile MICS service

Message ID 20230905070912.82340-3-nitin.jadhav@nxp.com
State New
Headers show
Series Implementation of MICS and MICP | expand

Commit Message

Nitin Jadhav Sept. 5, 2023, 7:09 a.m. UTC
- Implementation of functions related profile and service for MICS and MICP
- Specifications referred for implementation:
MICS - MICS_v1.0.pdf
MICP - MICP_v1.0.pdf

Co-developed-by: Mahesh Talewad <mahesh.talewad@nxp.com>
Signed-off-by: Mahesh Talewad <mahesh.talewad@nxp.com>
Signed-off-by: Nitin Jadhav <nitin.jadhav@nxp.com>
---
 Makefile.am       |   1 +
 src/shared/micp.c | 887 ++++++++++++++++++++++++++++++++++++++++++++++
 src/shared/micp.h |  83 +++++
 3 files changed, 971 insertions(+)
 create mode 100644 src/shared/micp.c
 create mode 100644 src/shared/micp.h
diff mbox series

Patch

diff --git a/Makefile.am b/Makefile.am
index 4b9b7e5cd..6f40f2a74 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -233,6 +233,7 @@  shared_sources = src/shared/io.h src/shared/timeout.h \
 			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/micp.c src/shared/micp.h \
 			src/shared/csip.c src/shared/csip.h \
 			src/shared/bass.h src/shared/bass.c \
 			src/shared/lc3.h src/shared/tty.h
diff --git a/src/shared/micp.c b/src/shared/micp.c
new file mode 100644
index 000000000..90d05b301
--- /dev/null
+++ b/src/shared/micp.c
@@ -0,0 +1,887 @@ 
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2023  NXP Semiconductors. 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 "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-helpers.h"
+#include "src/shared/micp.h"
+
+#define DBG(_micp, fmt, arg...) \
+	micp_debug(_micp, "%s:%s() " fmt, __FILE__, __func__, ##arg)
+
+/* Application error codes */
+#define MICP_ERROR_MUTE_DISABLED            0x80
+#define MICP_ERROR_VALUE_NOT_ALLOWED        0x13
+#define BT_ATT_ERROR_OPCODE_NOT_SUPPORTED   0x81
+
+/* Mute char values */
+#define MICS_NOT_MUTED  0x00
+#define MICS_MUTED      0x01
+#define MICS_DISABLED   0x02
+
+static struct queue *micp_db;
+static struct queue *micp_cbs;
+static struct queue *sessions;
+
+struct bt_micp_cb {
+	unsigned int id;
+	bt_micp_func_t attached;
+	bt_micp_func_t detached;
+	void *user_data;
+};
+
+typedef void (*micp_func_t)(struct bt_micp *micp, bool success,
+				uint8_t att_ecode, const uint8_t *value,
+				uint16_t length, void *user_data);
+
+struct bt_micp_pending {
+	unsigned int id;
+	struct bt_micp *micp;
+	micp_func_t func;
+	void *userdata;
+};
+
+struct bt_micp_ready {
+	unsigned int id;
+	bt_micp_ready_func_t func;
+	bt_micp_destroy_func_t destroy;
+	void *data;
+};
+
+typedef void (*micp_notify_t)(struct bt_micp *micp, uint16_t value_handle,
+				const uint8_t *value, uint16_t length,
+				void *user_data);
+
+struct bt_micp_notify {
+	unsigned int id;
+	struct bt_micp *micp;
+	micp_notify_t func;
+	void *user_data;
+};
+
+static void *iov_pull_mem(struct iovec *iov, size_t len)
+{
+	void *data = iov->iov_base;
+
+	if (iov->iov_len < len)
+		return NULL;
+
+	iov->iov_base += len;
+	iov->iov_len -= len;
+
+	return data;
+}
+
+static struct bt_micp_db *micp_get_mdb(struct bt_micp *micp)
+{
+	if (!micp)
+		return NULL;
+
+	if (micp->ldb)
+		return micp->ldb;
+
+	return NULL;
+}
+
+static uint8_t *mdb_get_mute_state(struct bt_micp_db *vdb)
+{
+	if (!vdb->mics)
+		return NULL;
+
+	return &(vdb->mics->mute_stat);
+}
+
+struct bt_mics *micp_get_mics(struct bt_micp *micp)
+{
+	if (!micp)
+		return NULL;
+
+	if (micp->rdb->mics)
+		return micp->rdb->mics;
+
+	micp->rdb->mics = new0(struct bt_mics, 1);
+	micp->rdb->mics->mdb = micp->rdb;
+
+	return micp->rdb->mics;
+}
+
+static void micp_detached(void *data, void *user_data)
+{
+	struct bt_micp_cb *cb = data;
+	struct bt_micp *micp = user_data;
+
+	cb->detached(micp, cb->user_data);
+}
+
+void bt_micp_detach(struct bt_micp *micp)
+{
+	if (!queue_remove(sessions, micp))
+		return;
+
+	bt_gatt_client_unref(micp->client);
+	micp->client = NULL;
+
+	queue_foreach(micp_cbs, micp_detached, micp);
+}
+
+static void micp_db_free(void *data)
+{
+	struct bt_micp_db *mdb = data;
+
+	if (!mdb)
+		return;
+
+	gatt_db_unref(mdb->db);
+
+	free(mdb->mics);
+	free(mdb);
+}
+
+static void micp_ready_free(void *data)
+{
+	struct bt_micp_ready *ready = data;
+
+	if (ready->destroy)
+		ready->destroy(ready->data);
+
+	free(ready);
+}
+
+static void micp_free(void *data)
+{
+	struct bt_micp *micp = data;
+
+	bt_micp_detach(micp);
+
+	micp_db_free(micp->rdb);
+
+	queue_destroy(micp->pending, NULL);
+	queue_destroy(micp->ready_cbs, micp_ready_free);
+
+	free(micp);
+}
+
+bool bt_micp_set_user_data(struct bt_micp *micp, void *user_data)
+{
+
+	if (!micp)
+		return false;
+
+	micp->user_data = user_data;
+
+	return true;
+}
+
+static bool micp_db_match(const void *data, const void *match_data)
+{
+	const struct bt_micp_db *mdb = data;
+	const struct gatt_db *db = match_data;
+
+	return (mdb->db == db);
+}
+
+struct bt_att *bt_micp_get_att(struct bt_micp *micp)
+{
+	if (!micp)
+		return NULL;
+
+	if (micp->att)
+		return micp->att;
+
+	return bt_gatt_client_get_att(micp->client);
+}
+
+struct bt_micp *bt_micp_ref(struct bt_micp *micp)
+{
+	if (!micp)
+		return NULL;
+
+	__sync_fetch_and_add(&micp->ref_count, 1);
+
+	return micp;
+}
+
+void bt_micp_unref(struct bt_micp *micp)
+{
+	if (!micp)
+		return;
+
+	if (__sync_sub_and_fetch(&micp->ref_count, 1))
+		return;
+
+	micp_free(micp);
+}
+
+static void micp_debug(struct bt_micp *micp, const char *format, ...)
+{
+	va_list ap;
+
+	if (!micp || !format || !micp->debug_func)
+		return;
+
+	va_start(ap, format);
+	util_debug_va(micp->debug_func, micp->debug_data, format, ap);
+	va_end(ap);
+}
+
+static void micp_disconnected(int err, void *user_data)
+{
+	struct bt_micp *micp = user_data;
+
+	DBG(micp, "micp %p disconnected err %d", micp, err);
+
+	bt_micp_detach(micp);
+}
+
+static struct bt_micp *micp_get_session(struct bt_att *att, struct gatt_db *db)
+{
+	const struct queue_entry *entry;
+	struct bt_micp *micp;
+
+	for (entry = queue_get_entries(sessions); entry; entry = entry->next) {
+		struct bt_micp *micp = entry->data;
+
+		if (att == bt_micp_get_att(micp))
+			return micp;
+	}
+
+	micp = bt_micp_new(db, NULL);
+	micp->att = att;
+
+	bt_att_register_disconnect(att, micp_disconnected, micp, NULL);
+
+	bt_micp_attach(micp, NULL);
+
+	return micp;
+}
+
+static void mics_mute_read(struct gatt_db_attribute *attrib,
+			unsigned int id, uint16_t offset,
+			uint8_t opcode, struct bt_att *att,
+			void *user_data)
+{
+	struct bt_mics *mics = user_data;
+	struct iovec iov;
+
+	iov.iov_base = &mics->mute_stat;
+	iov.iov_len = sizeof(mics->mute_stat);
+
+	gatt_db_attribute_read_result(attrib, id, 0, iov.iov_base,
+								  iov.iov_len);
+}
+
+static uint8_t mics_not_muted(struct bt_mics *mics, struct bt_micp *micp,
+							  struct iovec *iov)
+{
+	struct bt_micp_db *mdb;
+	uint8_t *mute_state;
+
+	DBG(micp, "Mute state OP: Not Muted");
+
+	mdb = micp_get_mdb(micp);
+	if (!mdb) {
+		DBG(micp, "error: MDB not available");
+		return 0;
+	}
+
+	mute_state = mdb_get_mute_state(mdb);
+	if (!mute_state) {
+		DBG(micp, "Error : Mute State not available");
+		return 0;
+	}
+
+	*mute_state = MICS_NOT_MUTED;
+
+	gatt_db_attribute_notify(mdb->mics->ms, (void *)mute_state,
+				sizeof(uint8_t), bt_micp_get_att(micp));
+
+	return 0;
+}
+
+static uint8_t mics_muted(struct bt_mics *mics, struct bt_micp *micp,
+						  struct iovec *iov)
+{
+	struct bt_micp_db *mdb;
+	uint8_t *mute_state;
+
+	DBG(micp, "Mute state OP: Muted");
+
+	mdb = micp_get_mdb(micp);
+	if (!mdb) {
+		DBG(micp, "error: MDB not available");
+		return 0;
+	}
+
+	mute_state = mdb_get_mute_state(mdb);
+
+	*mute_state = MICS_MUTED;
+
+	gatt_db_attribute_notify(mdb->mics->ms, (void *)mute_state,
+				sizeof(uint8_t), bt_micp_get_att(micp));
+
+	return 0;
+}
+
+#define MICS_OP(_str, _op, _size, _func) \
+	{                                    \
+		.str = _str,                     \
+		.op = _op,                       \
+		.size = _size,                   \
+		.func = _func,                   \
+	}
+
+struct mics_op_handler {
+	const char *str;
+	uint8_t op;
+	size_t size;
+	uint8_t (*func)(struct bt_mics *mics, struct bt_micp *micp,
+					struct iovec *iov);
+} micp_handlers[] = {
+	MICS_OP("Not Muted", MICS_NOT_MUTED,
+			sizeof(uint8_t), mics_not_muted),
+	MICS_OP("Muted", MICS_MUTED,
+			sizeof(uint8_t), mics_muted),
+	{}};
+
+static void mics_mute_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)
+{
+	struct bt_mics *mics = user_data;
+	struct bt_micp *micp = micp_get_session(att, mics->mdb->db);
+	struct iovec iov = {
+		.iov_base = (void *)value,
+		.iov_len = len,
+	};
+	uint8_t *micp_op, *mute_state;
+	struct mics_op_handler *handler;
+	uint8_t ret = BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+	struct bt_micp_db *mdb;
+
+	DBG(micp, "MICS Mute Char write: len: %ld: %ld", len, iov.iov_len);
+
+	if (offset) {
+		DBG(micp, "invalid offset: %d", offset);
+		ret = BT_ATT_ERROR_INVALID_OFFSET;
+		goto respond;
+	}
+
+	if (len < sizeof(*micp_op)) {
+		DBG(micp, "invalid length: %ld < %ld sizeof(param)", len,
+			sizeof(*micp_op));
+		ret = BT_ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LEN;
+		goto respond;
+	}
+
+	micp_op = iov_pull_mem(&iov, sizeof(*micp_op));
+
+	if ((*micp_op == MICS_DISABLED) || (*micp_op != MICS_NOT_MUTED
+		&& *micp_op != MICS_MUTED)) {
+		DBG(micp, "Invalid operation - MICS DISABLED/RFU mics op:%d",
+					micp_op);
+		ret = MICP_ERROR_VALUE_NOT_ALLOWED;
+		goto respond;
+	}
+
+	mdb = micp_get_mdb(micp);
+	if (!mdb) {
+		DBG(micp, "error: MDB not available");
+		goto respond;
+	}
+
+	mute_state = mdb_get_mute_state(mdb);
+	if (*mute_state == MICS_DISABLED) {
+		DBG(micp, "state: MICS DISABLED , can not write value: %d",
+				*micp_op);
+		ret = MICP_ERROR_MUTE_DISABLED;
+		goto respond;
+	}
+
+	for (handler = micp_handlers; handler && handler->str; handler++) {
+		DBG(micp, "handler->op: %d micp_op: %d iov.iov_len: %ld",
+					handler->op, *micp_op, iov.iov_len);
+		if (handler->op != *micp_op)
+			continue;
+
+		if (len < handler->size) {
+			DBG(micp, "invalid len %ld : %ld < %ld handler->size",
+			len, iov.iov_len, handler->size);
+			ret = BT_ATT_ERROR_OPCODE_NOT_SUPPORTED;
+			goto respond;
+		}
+
+		break;
+	}
+
+	if (handler && handler->str) {
+		DBG(micp, "%s", handler->str);
+
+		ret = handler->func(mics, micp, &iov);
+	} else {
+		DBG(micp, "unknown opcode 0x%02x", *micp_op);
+		ret = BT_ATT_ERROR_OPCODE_NOT_SUPPORTED;
+	}
+
+respond:
+	gatt_db_attribute_write_result(attrib, id, ret);
+}
+
+static struct bt_mics *mics_new(struct gatt_db *db)
+{
+	struct bt_mics *mics;
+	bt_uuid_t uuid;
+
+	if (!db)
+		return NULL;
+
+	mics = new0(struct bt_mics, 1);
+
+	mics->mute_stat = MICS_MUTED;
+
+	/* Populate DB with MICS attributes */
+	bt_uuid16_create(&uuid, MICS_UUID);
+	mics->service = gatt_db_add_service(db, &uuid, true, 4);
+
+	bt_uuid16_create(&uuid, MUTE_CHRC_UUID);
+	mics->ms = gatt_db_service_add_characteristic(mics->service,
+				&uuid,
+				BT_ATT_PERM_READ | BT_ATT_PERM_WRITE,
+				BT_GATT_CHRC_PROP_READ | BT_GATT_CHRC_PROP_WRITE
+				| BT_GATT_CHRC_PROP_NOTIFY,
+				mics_mute_read, mics_mute_write,
+				mics);
+
+	mics->ms_ccc = gatt_db_service_add_ccc(mics->service,
+				BT_ATT_PERM_READ | BT_ATT_PERM_WRITE);
+
+	gatt_db_service_set_active(mics->service, true);
+
+	return mics;
+}
+
+static struct bt_micp_db *micp_db_new(struct gatt_db *db)
+{
+	struct bt_micp_db *mdb;
+
+	if (!db)
+		return NULL;
+
+	mdb = new0(struct bt_micp_db, 1);
+	mdb->db = gatt_db_ref(db);
+
+	if (!micp_db)
+		micp_db = queue_new();
+
+	mdb->mics = mics_new(db);
+	mdb->mics->mdb = mdb;
+
+	queue_push_tail(micp_db, mdb);
+
+	return mdb;
+}
+
+static struct bt_micp_db *micp_get_db(struct gatt_db *db)
+{
+	struct bt_micp_db *mdb;
+
+	mdb = queue_find(micp_db, micp_db_match, db);
+	if (mdb)
+		return mdb;
+
+	return micp_db_new(db);
+}
+
+void bt_micp_add_db(struct gatt_db *db)
+{
+	micp_db_new(db);
+}
+
+bool bt_micp_set_debug(struct bt_micp *micp, bt_micp_debug_func_t func,
+			void *user_data, bt_micp_destroy_func_t destroy)
+{
+	if (!micp)
+		return false;
+
+	if (micp->debug_destroy)
+		micp->debug_destroy(micp->debug_data);
+
+	micp->debug_func = func;
+	micp->debug_destroy = destroy;
+	micp->debug_data = user_data;
+
+	return true;
+}
+
+unsigned int bt_micp_register(bt_micp_func_t attached, bt_micp_func_t detached,
+							  void *user_data)
+{
+	struct bt_micp_cb *cb;
+	static unsigned int id;
+
+	if (!attached && !detached)
+		return 0;
+
+	if (!micp_cbs)
+		micp_cbs = queue_new();
+
+	cb = new0(struct bt_micp_cb, 1);
+	cb->id = ++id ? id : ++id;
+	cb->attached = attached;
+	cb->detached = detached;
+	cb->user_data = user_data;
+
+	queue_push_tail(micp_cbs, cb);
+
+	return cb->id;
+}
+
+static bool match_id(const void *data, const void *match_data)
+{
+	const struct bt_micp_cb *cb = data;
+	unsigned int id = PTR_TO_UINT(match_data);
+
+	return (cb->id == id);
+}
+
+bool bt_micp_unregister(unsigned int id)
+{
+	struct bt_micp_cb *cb;
+
+	cb = queue_remove_if(micp_cbs, match_id, UINT_TO_PTR(id));
+	if (!cb)
+		return false;
+
+	free(cb);
+
+	return true;
+}
+
+struct bt_micp *bt_micp_new(struct gatt_db *ldb, struct gatt_db *rdb)
+{
+	struct bt_micp *micp;
+	struct bt_micp_db *mdb;
+
+	if (!ldb)
+		return NULL;
+
+	mdb = micp_get_db(ldb);
+	if (!mdb)
+		return NULL;
+
+	micp = new0(struct bt_micp, 1);
+	micp->ldb = mdb;
+	micp->pending = queue_new();
+	micp->ready_cbs = queue_new();
+
+	if (!rdb)
+		goto done;
+
+	mdb = new0(struct bt_micp_db, 1);
+	mdb->db = gatt_db_ref(rdb);
+
+	micp->rdb = mdb;
+
+done:
+	bt_micp_ref(micp);
+
+	return micp;
+}
+
+static void micp_pending_destroy(void *data)
+{
+	struct bt_micp_pending *pending = data;
+	struct bt_micp *micp = pending->micp;
+
+	if (queue_remove_if(micp->pending, NULL, pending))
+		free(pending);
+}
+
+static void micp_pending_complete(bool success, uint8_t att_ecode,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
+{
+	struct bt_micp_pending *pending = user_data;
+
+	if (pending->func)
+		pending->func(pending->micp, success, att_ecode, value, length,
+					  pending->userdata);
+}
+
+static void micp_read_value(struct bt_micp *micp, uint16_t value_handle,
+				micp_func_t func, void *user_data)
+{
+	struct bt_micp_pending *pending;
+
+	pending = new0(struct bt_micp_pending, 1);
+	pending->micp = micp;
+	pending->func = func;
+	pending->userdata = user_data;
+
+	pending->id = bt_gatt_client_read_value(micp->client, value_handle,
+					micp_pending_complete, pending,
+					micp_pending_destroy);
+
+	if (!pending->id) {
+		DBG(micp, "unable to send read request");
+		free(pending);
+		return;
+	}
+
+	queue_push_tail(micp->pending, pending);
+}
+
+static void micp_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_micp_notify *notify = user_data;
+
+	if (att_ecode)
+		DBG(notify->micp, "MICP register failed 0x%04x", att_ecode);
+}
+
+static void micp_notify(uint16_t value_handle, const uint8_t *value,
+				uint16_t length, void *user_data)
+{
+	struct bt_micp_notify *notify = user_data;
+
+	if (notify->func)
+		notify->func(notify->micp, value_handle, value, length,
+					 notify->user_data);
+}
+
+static void micp_notify_destroy(void *data)
+{
+	struct bt_micp_notify *notify = data;
+	struct bt_micp *micp = notify->micp;
+
+	if (queue_remove_if(micp->notify, NULL, notify))
+		free(notify);
+}
+
+static unsigned int micp_register_notify(struct bt_micp *micp,
+					uint16_t value_handle,
+					micp_notify_t func,
+					void *user_data)
+{
+	struct bt_micp_notify *notify;
+
+	notify = new0(struct bt_micp_notify, 1);
+	notify->micp = micp;
+	notify->func = func;
+	notify->user_data = user_data;
+
+	notify->id = bt_gatt_client_register_notify(micp->client,
+					value_handle, micp_register,
+					micp_notify, notify,
+					micp_notify_destroy);
+	if (!notify->id) {
+		DBG(micp, "Unable to register for notifications");
+		free(notify);
+		return 0;
+	}
+
+	queue_push_tail(micp->notify, notify);
+
+	return notify->id;
+}
+
+static void micp_mute_state_notify(struct bt_micp *micp, uint16_t value_handle,
+					const uint8_t *value, uint16_t length,
+					void *user_data)
+{
+	uint8_t mute_state;
+
+	memcpy(&mute_state, value, sizeof(mute_state));
+
+	DBG(micp, "Mute state: 0x%x", mute_state);
+}
+
+static void read_mute_state(struct bt_micp *micp, bool success,
+					uint8_t att_ecode, const uint8_t *value,
+					uint16_t length, void *user_data)
+{
+	uint8_t *mute_state;
+	struct iovec iov = {
+		.iov_base = (void *)value,
+		.iov_len = length,
+	};
+
+	if (!success) {
+		DBG(micp, "Unable to read Mute state: error 0x%02x", att_ecode);
+		return;
+	}
+
+	mute_state = iov_pull_mem(&iov, sizeof(uint8_t));
+	if (mute_state == NULL) {
+		DBG(micp, "Unable to get Mute state");
+		return;
+	}
+
+	DBG(micp, "Mute state: %x", *mute_state);
+}
+
+static void foreach_mics_char(struct gatt_db_attribute *attr, void *user_data)
+{
+	struct bt_micp *micp = user_data;
+	uint16_t value_handle;
+	bt_uuid_t uuid, uuid_mute;
+	struct bt_mics *mics;
+
+	if (!gatt_db_attribute_get_char_data(attr, NULL, &value_handle,
+			NULL, NULL, &uuid))
+		return;
+
+	bt_uuid16_create(&uuid_mute, MUTE_CHRC_UUID);
+	if (!bt_uuid_cmp(&uuid, &uuid_mute)) {
+		DBG(micp, "MICS Mute characteristic found: handle 0x%04x",
+				value_handle);
+
+		mics = micp_get_mics(micp);
+		if (!mics || mics->ms)
+			return;
+
+		mics->ms = attr;
+
+		micp_read_value(micp, value_handle, read_mute_state, micp);
+
+		micp->mute_id = micp_register_notify(micp, value_handle,
+						micp_mute_state_notify, NULL);
+	}
+}
+
+static void foreach_mics_service(struct gatt_db_attribute *attr,
+					void *user_data)
+{
+	struct bt_micp *micp = user_data;
+	struct bt_mics *mics = micp_get_mics(micp);
+
+	mics->service = attr;
+
+	gatt_db_service_set_claimed(attr, true);
+	gatt_db_service_foreach_char(attr, foreach_mics_char, micp);
+}
+
+unsigned int bt_micp_ready_register(struct bt_micp *micp,
+				bt_micp_ready_func_t func, void *user_data,
+				bt_micp_destroy_func_t destroy)
+{
+	struct bt_micp_ready *ready;
+	static unsigned int id;
+
+	DBG(micp, "bt_micp_ready_register_Entry\n");
+	if (!micp)
+		return 0;
+
+	ready = new0(struct bt_micp_ready, 1);
+	ready->id = ++id ? id : ++id;
+	ready->func = func;
+	ready->destroy = destroy;
+	ready->data = user_data;
+
+	queue_push_tail(micp->ready_cbs, ready);
+
+	return ready->id;
+}
+
+static bool match_ready_id(const void *data, const void *match_data)
+{
+	const struct bt_micp_ready *ready = data;
+	unsigned int id = PTR_TO_UINT(match_data);
+
+	return (ready->id == id);
+}
+
+bool bt_micp_ready_unregister(struct bt_micp *micp, unsigned int id)
+{
+	struct bt_micp_ready *ready;
+
+	ready = queue_remove_if(micp->ready_cbs, match_ready_id,
+						UINT_TO_PTR(id));
+	if (!ready)
+		return false;
+
+	micp_ready_free(ready);
+
+	return true;
+}
+
+static struct bt_micp *bt_micp_ref_safe(struct bt_micp *micp)
+{
+	if (!micp || !micp->ref_count)
+		return NULL;
+
+	return bt_micp_ref(micp);
+}
+
+static void micp_notify_ready(struct bt_micp *micp)
+{
+	const struct queue_entry *entry;
+
+	if (!bt_micp_ref_safe(micp))
+		return;
+
+	for (entry = queue_get_entries(micp->ready_cbs); entry;
+							entry = entry->next) {
+		struct bt_micp_ready *ready = entry->data;
+
+		ready->func(micp, ready->data);
+	}
+
+	bt_micp_unref(micp);
+}
+
+static void micp_idle(void *data)
+{
+	struct bt_micp *micp = data;
+
+	micp->idle_id = 0;
+	micp_notify_ready(micp);
+}
+
+bool bt_micp_attach(struct bt_micp *micp, struct bt_gatt_client *client)
+{
+	bt_uuid_t uuid;
+
+	if (!sessions)
+		sessions = queue_new();
+
+	queue_push_tail(sessions, micp);
+
+	if (!client)
+		return true;
+
+	if (micp->client)
+		return false;
+
+	micp->client = bt_gatt_client_clone(client);
+	if (!micp->client)
+		return false;
+
+	bt_gatt_client_idle_register(micp->client, micp_idle, micp, NULL);
+
+	bt_uuid16_create(&uuid, MICS_UUID);
+	gatt_db_foreach_service(micp->ldb->db, &uuid, foreach_mics_service,
+						micp);
+	return true;
+}
diff --git a/src/shared/micp.h b/src/shared/micp.h
new file mode 100644
index 000000000..c881aded9
--- /dev/null
+++ b/src/shared/micp.h
@@ -0,0 +1,83 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2023  NXP Semiconductors. All rights reserved.
+ *
+ */
+#include <stdbool.h>
+#include <inttypes.h>
+
+#include "src/shared/io.h"
+#include "src/shared/gatt-client.h"
+
+struct bt_mics;
+struct bt_micp;
+
+typedef void (*bt_micp_ready_func_t)(struct bt_micp *micp, void *user_data);
+typedef void (*bt_micp_destroy_func_t)(void *user_data);
+typedef void (*bt_micp_debug_func_t)(const char *str, void *user_data);
+typedef void (*bt_micp_func_t)(struct bt_micp *micp, void *user_data);
+
+struct bt_micp_db {
+	struct gatt_db *db;
+	struct bt_mics *mics;
+};
+
+struct bt_mics {
+	struct bt_micp_db *mdb;
+	uint8_t mute_stat;
+	struct gatt_db_attribute *service;
+	struct gatt_db_attribute *ms;
+	struct gatt_db_attribute *ms_ccc;
+};
+
+struct bt_micp {
+	int ref_count;
+	struct bt_micp_db *ldb;
+	struct bt_micp_db *rdb;
+	struct bt_gatt_client *client;
+	struct bt_att *att;
+	unsigned int mute_id;
+
+	unsigned int idle_id;
+	uint8_t mute;
+
+	struct queue *notify;
+	struct queue *pending;
+	struct queue *ready_cbs;
+
+	bt_micp_debug_func_t debug_func;
+	bt_micp_destroy_func_t debug_destroy;
+
+	void *debug_data;
+	void *user_data;
+};
+
+struct bt_micp *bt_micp_ref(struct bt_micp *micp);
+void bt_micp_unref(struct bt_micp *micp);
+
+void bt_micp_add_db(struct gatt_db *db);
+
+bool bt_micp_attach(struct bt_micp *micp, struct bt_gatt_client *client);
+void bt_micp_detach(struct bt_micp *micp);
+
+bool bt_micp_set_debug(struct bt_micp *micp, bt_micp_debug_func_t func,
+		void *user_data, bt_micp_destroy_func_t destroy);
+
+struct bt_att *bt_micp_get_att(struct bt_micp *micp);
+
+bool bt_micp_set_user_data(struct bt_micp *micp, void *user_data);
+
+/* session related functions */
+unsigned int bt_micp_register(bt_micp_func_t attached, bt_micp_func_t detached,
+					void *user_data);
+unsigned int bt_micp_ready_register(struct bt_micp *micp,
+				bt_micp_ready_func_t func, void *user_data,
+				bt_micp_destroy_func_t destroy);
+bool bt_micp_ready_unregister(struct bt_micp *micp, unsigned int id);
+
+bool bt_micp_unregister(unsigned int id);
+struct bt_micp *bt_micp_new(struct gatt_db *ldb, struct gatt_db *rdb);
+struct bt_mics *micp_get_mics(struct bt_micp *micp);