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From:   Sathish Narasimman <sathish.narasimman@intel.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     Sathish Narasimman <sathish.narasimman@intel.com>
Subject: [PATCH BlueZ 1/1] sharaed/vcp: Add bt_vcp_set_debug
Date:   Tue, 20 Sep 2022 15:58:47 +0530
Message-Id: <20220920102847.599893-1-sathish.narasimman@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This enables debug with bt_vcp_set_debug.
---
 profiles/audio/vcp.c |   7 ++
 src/shared/vcp.c     | 238 +++++++++++++++++++++++++++----------------
 src/shared/vcp.h     |   5 +
 3 files changed, 163 insertions(+), 87 deletions(-)

diff --git a/profiles/audio/vcp.c b/profiles/audio/vcp.c
index e7e84174e7d4..b42b0a4f79dd 100644
--- a/profiles/audio/vcp.c
+++ b/profiles/audio/vcp.c
@@ -62,6 +62,11 @@ struct vcp_data {
 
 static struct queue *sessions;
 
+static void vcp_debug(const char *str, void *user_data)
+{
+	DBG_IDX(0xffff, "%s", str);
+}
+
 static int vcp_disconnect(struct btd_service *service)
 {
 	DBG("");
@@ -87,6 +92,8 @@ static void vcp_data_add(struct vcp_data *data)
 		return;
 	}
 
+	bt_vcp_set_debug(data->vcp, vcp_debug, NULL, NULL);
+
 	if (!sessions)
 		sessions = queue_new();
 
diff --git a/src/shared/vcp.c b/src/shared/vcp.c
index 4f8dc37e3c3e..3d0ff016d805 100644
--- a/src/shared/vcp.c
+++ b/src/shared/vcp.c
@@ -26,7 +26,9 @@
 #include "src/shared/gatt-server.h"
 #include "src/shared/gatt-client.h"
 #include "src/shared/vcp.h"
-#include "src/log.h"
+
+#define DBG(_vcp, fmt, arg...) \
+	vcp_debug(_vcp, "%s:%s() " fmt, __FILE__, __func__, ## arg)
 
 #define VCP_STEP_SIZE 1
 
@@ -87,8 +89,11 @@ struct bt_vcp {
 	unsigned int vstate_id;
 	unsigned int vflag_id;
 
+	struct queue *notify;
 	struct queue *pending;
 
+	bt_vcp_debug_func_t debug_func;
+	bt_vcp_destroy_func_t debug_destroy;
 	void *debug_data;
 	void *user_data;
 };
@@ -262,11 +267,23 @@ void bt_vcp_unref(struct bt_vcp *vcp)
 	vcp_free(vcp);
 }
 
+static void vcp_debug(struct bt_vcp *vcp, const char *format, ...)
+{
+	va_list ap;
+
+	if (!vcp || !format || !vcp->debug_func)
+		return;
+
+	va_start(ap, format);
+	util_debug_va(vcp->debug_func, vcp->debug_data, format, ap);
+	va_end(ap);
+}
+
 static void vcp_disconnected(int err, void *user_data)
 {
 	struct bt_vcp *vcp = user_data;
 
-	DBG("vcp %p disconnected err %d", vcp, err);
+	DBG(vcp, "vcp %p disconnected err %d", vcp, err);
 
 	bt_vcp_detach(vcp);
 }
@@ -301,17 +318,17 @@ static uint8_t vcs_rel_vol_down(struct bt_vcs *vcs, struct bt_vcp *vcp,
 	struct vol_state *vstate;
 	uint8_t	*change_counter;
 
-	DBG("");
+	DBG(vcp, "Volume Down");
 
 	vdb = vcp_get_vdb(vcp);
 	if (!vdb) {
-		DBG("error: VDB not availalbe");
+		DBG(vcp, "error: VDB not availalbe");
 		return 0;
 	}
 
 	vstate = vdb_get_vstate(vdb);
 	if (!vstate) {
-		DBG("error: VSTATE not availalbe");
+		DBG(vcp, "error: VSTATE not availalbe");
 		return 0;
 	}
 
@@ -320,7 +337,7 @@ static uint8_t vcs_rel_vol_down(struct bt_vcs *vcs, struct bt_vcp *vcp,
 		return 0;
 
 	if (*change_counter != vstate->counter) {
-		DBG("Change Counter Mismatch Volume not decremented!");
+		DBG(vcp, "Change Counter Mismatch Volume not decremented!");
 		return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
 	}
 
@@ -340,17 +357,17 @@ static uint8_t vcs_rel_vol_up(struct bt_vcs *vcs, struct bt_vcp *vcp,
 	struct vol_state *vstate;
 	uint8_t	*change_counter;
 
-	DBG("");
+	DBG(vcp, "Volume Up");
 
 	vdb = vcp_get_vdb(vcp);
 	if (!vdb) {
-		DBG("error: VDB not availalbe");
+		DBG(vcp, "error: VDB not availalbe");
 		return 0;
 	}
 
 	vstate = vdb_get_vstate(vdb);
 	if (!vstate) {
-		DBG("error: VCP database not availalbe!!!!");
+		DBG(vcp, "error: VCP database not availalbe!!!!");
 		return 0;
 	}
 
@@ -359,7 +376,7 @@ static uint8_t vcs_rel_vol_up(struct bt_vcs *vcs, struct bt_vcp *vcp,
 		return 0;
 
 	if (*change_counter != vstate->counter) {
-		DBG("Change Counter Mismatch Volume not decremented!");
+		DBG(vcp, "Change Counter Mismatch Volume not decremented!");
 		return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
 	}
 
@@ -379,17 +396,17 @@ static uint8_t vcs_unmute_rel_vol_down(struct bt_vcs *vcs, struct bt_vcp *vcp,
 	struct vol_state *vstate;
 	uint8_t	*change_counter;
 
-	DBG("");
+	DBG(vcp, "Un Mute and Volume Down");
 
 	vdb = vcp_get_vdb(vcp);
 	if (!vdb) {
-		DBG("error: VDB not availalbe");
+		DBG(vcp, "error: VDB not availalbe");
 		return 0;
 	}
 
 	vstate = vdb_get_vstate(vdb);
 	if (!vstate) {
-		DBG("error: VCP database not availalbe!!!!");
+		DBG(vcp, "error: VCP database not availalbe!!!!");
 		return 0;
 	}
 
@@ -398,7 +415,7 @@ static uint8_t vcs_unmute_rel_vol_down(struct bt_vcs *vcs, struct bt_vcp *vcp,
 		return 0;
 
 	if (*change_counter != vstate->counter) {
-		DBG("Change Counter Mismatch Volume not decremented!");
+		DBG(vcp, "Change Counter Mismatch Volume not decremented!");
 		return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
 	}
 
@@ -419,17 +436,17 @@ static uint8_t vcs_unmute_rel_vol_up(struct bt_vcs *vcs, struct bt_vcp *vcp,
 	struct vol_state *vstate;
 	uint8_t	*change_counter;
 
-	DBG("");
+	DBG(vcp, "UN Mute and Volume Up");
 
 	vdb = vcp_get_vdb(vcp);
 	if (!vdb) {
-		DBG("error: VDB not availalbe");
+		DBG(vcp, "error: VDB not availalbe");
 		return 0;
 	}
 
 	vstate = vdb_get_vstate(vdb);
 	if (!vstate) {
-		DBG("error: VSTATE not availalbe");
+		DBG(vcp, "error: VSTATE not availalbe");
 		return 0;
 	}
 
@@ -438,7 +455,7 @@ static uint8_t vcs_unmute_rel_vol_up(struct bt_vcs *vcs, struct bt_vcp *vcp,
 		return 0;
 
 	if (*change_counter != vstate->counter) {
-		DBG("Change Counter Mismatch Volume not decremented!");
+		DBG(vcp, "Change Counter Mismatch Volume not decremented!");
 		return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
 	}
 
@@ -459,17 +476,17 @@ static uint8_t vcs_set_absolute_vol(struct bt_vcs *vcs, struct bt_vcp *vcp,
 	struct vol_state *vstate;
 	struct bt_vcs_ab_vol *req;
 
-	DBG("");
+	DBG(vcp, "Set Absolute Volume");
 
 	vdb = vcp_get_vdb(vcp);
 	if (!vdb) {
-		DBG("error: VDB not availalbe");
+		DBG(vcp, "error: VDB not availalbe");
 		return 0;
 	}
 
 	vstate = vdb_get_vstate(vdb);
 	if (!vstate) {
-		DBG("error: VSTATE not availalbe");
+		DBG(vcp, "error: VSTATE not availalbe");
 		return 0;
 	}
 
@@ -478,7 +495,7 @@ static uint8_t vcs_set_absolute_vol(struct bt_vcs *vcs, struct bt_vcp *vcp,
 		return 0;
 
 	if (req->change_counter != vstate->counter) {
-		DBG("Change Counter Mismatch Volume not decremented!");
+		DBG(vcp, "Change Counter Mismatch Volume not decremented!");
 		return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
 	}
 
@@ -498,17 +515,17 @@ static uint8_t vcs_unmute(struct bt_vcs *vcs, struct bt_vcp *vcp,
 	struct vol_state *vstate;
 	uint8_t	*change_counter;
 
-	DBG("");
+	DBG(vcp, "Un Mute");
 
 	vdb = vcp_get_vdb(vcp);
 	if (!vdb) {
-		DBG("error: VDB not availalbe");
+		DBG(vcp, "error: VDB not availalbe");
 		return 0;
 	}
 
 	vstate = vdb_get_vstate(vdb);
 	if (!vstate) {
-		DBG("error: VSTATE not availalbe");
+		DBG(vcp, "error: VSTATE not availalbe");
 		return 0;
 	}
 
@@ -517,7 +534,7 @@ static uint8_t vcs_unmute(struct bt_vcs *vcs, struct bt_vcp *vcp,
 		return 0;
 
 	if (*change_counter != vstate->counter) {
-		DBG("Change Counter Mismatch Volume not decremented!");
+		DBG(vcp, "Change Counter Mismatch Volume not decremented!");
 		return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
 	}
 
@@ -537,17 +554,17 @@ static uint8_t vcs_mute(struct bt_vcs *vcs, struct bt_vcp *vcp,
 	struct vol_state *vstate;
 	uint8_t	*change_counter;
 
-	DBG("");
+	DBG(vcp, "MUTE");
 
 	vdb = vcp_get_vdb(vcp);
 	if (!vdb) {
-		DBG("error: VDB not availalbe");
+		DBG(vcp, "error: VDB not availalbe");
 		return 0;
 	}
 
 	vstate = vdb_get_vstate(vdb);
 	if (!vstate) {
-		DBG("error: VSTATE not availalbe");
+		DBG(vcp, "error: VSTATE not availalbe");
 		return 0;
 	}
 
@@ -556,7 +573,7 @@ static uint8_t vcs_mute(struct bt_vcs *vcs, struct bt_vcp *vcp,
 		return 0;
 
 	if (*change_counter != vstate->counter) {
-		DBG("Change Counter Mismatch Volume not decremented!");
+		DBG(vcp, "Change Counter Mismatch Volume not decremented!");
 		return BT_ATT_ERROR_INVALID_CHANGE_COUNTER;
 	}
 
@@ -622,16 +639,16 @@ static void vcs_cp_write(struct gatt_db_attribute *attrib,
 	struct vcs_op_handler *handler;
 	uint8_t ret = BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
 
-	DBG("");
+	DBG(vcp, "VCP Control Point Write");
 
 	if (offset) {
-		DBG("invalid offset %d", offset);
+		DBG(vcp, "invalid offset %d", offset);
 		ret = BT_ATT_ERROR_INVALID_OFFSET;
 		goto respond;
 	}
 
 	if (len < sizeof(*vcp_op)) {
-		DBG("invalid len %ld < %ld sizeof(*param)", len,
+		DBG(vcp, "invalid len %ld < %ld sizeof(*param)", len,
 							sizeof(*vcp_op));
 		ret = BT_ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LEN;
 		goto respond;
@@ -639,14 +656,12 @@ static void vcs_cp_write(struct gatt_db_attribute *attrib,
 
 	vcp_op = iov_pull_mem(&iov, sizeof(*vcp_op));
 
-	DBG("op: %x", *vcp_op);
-
 	for (handler = vcp_handlers; handler && handler->str; handler++) {
 		if (handler->op != *vcp_op)
 			continue;
 
 		if (iov.iov_len < handler->size) {
-			DBG("invalid len %ld < %ld handler->size", len,
+			DBG(vcp, "invalid len %ld < %ld handler->size", len,
 			    handler->size);
 			ret = BT_ATT_ERROR_OPCODE_NOT_SUPPORTED;
 			goto respond;
@@ -656,11 +671,11 @@ static void vcs_cp_write(struct gatt_db_attribute *attrib,
 	}
 
 	if (handler && handler->str) {
-		DBG("%s", handler->str);
+		DBG(vcp, "%s", handler->str);
 
 		ret = handler->func(vcs, vcp, &iov);
 	} else {
-		DBG("Unknown opcode 0x%02x", *vcp_op);
+		DBG(vcp, "Unknown opcode 0x%02x", *vcp_op);
 		ret = BT_ATT_ERROR_OPCODE_NOT_SUPPORTED;
 	}
 
@@ -676,8 +691,6 @@ static void vcs_state_read(struct gatt_db_attribute *attrib,
 	struct bt_vcs *vcs = user_data;
 	struct iovec iov;
 
-	DBG("");
-
 	iov.iov_base = vcs->vstate;
 	iov.iov_len = sizeof(*vcs->vstate);
 
@@ -693,8 +706,6 @@ static void vcs_flag_read(struct gatt_db_attribute *attrib,
 	struct bt_vcs *vcs = user_data;
 	struct iovec iov;
 
-	DBG("vf: %x", vcs->vol_flag);
-
 	iov.iov_base = &vcs->vol_flag;
 	iov.iov_len = sizeof(vcs->vol_flag);
 
@@ -797,6 +808,22 @@ void bt_vcp_add_db(struct gatt_db *db)
 	vcp_db_new(db);
 }
 
+bool bt_vcp_set_debug(struct bt_vcp *vcp, bt_vcp_debug_func_t func,
+			void *user_data, bt_vcp_destroy_func_t destroy)
+{
+	if (!vcp)
+		return false;
+
+	if (vcp->debug_destroy)
+		vcp->debug_destroy(vcp->debug_data);
+
+	vcp->debug_func = func;
+	vcp->debug_destroy = destroy;
+	vcp->debug_data = user_data;
+
+	return true;
+}
+
 unsigned int bt_vcp_register(bt_vcp_func_t attached, bt_vcp_func_t detached,
 							void *user_data)
 {
@@ -871,40 +898,28 @@ done:
 	return vcp;
 }
 
-static void vcp_vstate_register(uint16_t att_ecode, void *user_data)
-{
-	DBG("");
-	if (att_ecode)
-		DBG("VCS register failed: 0x%04x", att_ecode);
-}
-
-static void vcp_vflag_register(uint16_t att_ecode, void *user_data)
-{
-	DBG("");
-	if (att_ecode)
-		DBG("VCS register failed: 0x%04x", att_ecode);
-}
-
-static void vcp_vstate_notify(uint16_t value_handle, const uint8_t *value,
-				uint16_t length, void *user_data)
+static void vcp_vstate_notify(struct bt_vcp *vcp, uint16_t value_handle,
+				const uint8_t *value, uint16_t length,
+				void *user_data)
 {
 	struct vol_state vstate;
 
 	memcpy(&vstate, value, sizeof(struct vol_state));
 
-	DBG("Vol Settings 0x%x", vstate.vol_set);
-	DBG("Mute Status 0x%x", vstate.mute);
-	DBG("Vol Counter 0x%x", vstate.counter);
+	DBG(vcp, "Vol Settings 0x%x", vstate.vol_set);
+	DBG(vcp, "Mute Status 0x%x", vstate.mute);
+	DBG(vcp, "Vol Counter 0x%x", vstate.counter);
 }
 
-static void vcp_vflag_notify(uint16_t value_handle, const uint8_t *value,
-				uint16_t length, void *user_data)
+static void vcp_vflag_notify(struct bt_vcp *vcp, uint16_t value_handle,
+			     const uint8_t *value, uint16_t length,
+			     void *user_data)
 {
 	uint8_t vflag;
 
 	memcpy(&vflag, value, sizeof(vflag));
 
-	DBG("Vol Flag 0x%x", vflag);
+	DBG(vcp, "Vol Flag 0x%x", vflag);
 }
 
 static void read_vol_flag(struct bt_vcp *vcp, bool success, uint8_t att_ecode,
@@ -918,17 +933,17 @@ static void read_vol_flag(struct bt_vcp *vcp, bool success, uint8_t att_ecode,
 	};
 
 	if (!success) {
-		DBG("Unable to read VCP Vol State: error 0x%02x", att_ecode);
+		DBG(vcp, "Unable to read Vol Flag: error 0x%02x", att_ecode);
 		return;
 	}
 
 	vol_flag = iov_pull_mem(&iov, sizeof(*vol_flag));
 	if (!vol_flag) {
-		DBG("Unable to get Vol State");
+		DBG(vcp, "Unable to get Vol Flag");
 		return;
 	}
 
-	DBG("Vol Flag:%x", *vol_flag);
+	DBG(vcp, "Vol Flag:%x", *vol_flag);
 }
 
 static void read_vol_state(struct bt_vcp *vcp, bool success, uint8_t att_ecode,
@@ -942,19 +957,19 @@ static void read_vol_state(struct bt_vcp *vcp, bool success, uint8_t att_ecode,
 	};
 
 	if (!success) {
-		DBG("Unable to read VCP Vol State: error 0x%02x", att_ecode);
+		DBG(vcp, "Unable to read Vol State: error 0x%02x", att_ecode);
 		return;
 	}
 
 	vs = iov_pull_mem(&iov, sizeof(*vs));
 	if (!vs) {
-		DBG("Unable to get Vol State");
+		DBG(vcp, "Unable to get Vol State");
 		return;
 	}
 
-	DBG("Vol Set:%x", vs->vol_set);
-	DBG("Vol Mute:%x", vs->mute);
-	DBG("Vol Counter:%x", vs->counter);
+	DBG(vcp, "Vol Set:%x", vs->vol_set);
+	DBG(vcp, "Vol Mute:%x", vs->mute);
+	DBG(vcp, "Vol Counter:%x", vs->counter);
 }
 
 static void vcp_pending_destroy(void *data)
@@ -991,7 +1006,7 @@ static void vcp_read_value(struct bt_vcp *vcp, uint16_t value_handle,
 						vcp_pending_complete, pending,
 						vcp_pending_destroy);
 	if (!pending->id) {
-		DBG("Unable to send Read request");
+		DBG(vcp, "Unable to send Read request");
 		free(pending);
 		return;
 	}
@@ -999,6 +1014,60 @@ static void vcp_read_value(struct bt_vcp *vcp, uint16_t value_handle,
 	queue_push_tail(vcp->pending, pending);
 }
 
+static void vcp_register(uint16_t att_ecode, void *user_data)
+{
+	struct bt_vcp_notify *notify = user_data;
+
+	if (att_ecode)
+		DBG(notify->vcp, "VCP register failed: 0x%04x", att_ecode);
+}
+
+static void vcp_notify(uint16_t value_handle, const uint8_t *value,
+				uint16_t length, void *user_data)
+{
+	struct bt_vcp_notify *notify = user_data;
+
+	if (notify->func)
+		notify->func(notify->vcp, value_handle, value, length,
+						notify->user_data);
+}
+
+static void vcp_notify_destroy(void *data)
+{
+	struct bt_vcp_notify *notify = data;
+	struct bt_vcp *vcp = notify->vcp;
+
+	if (queue_remove_if(vcp->notify, NULL, notify))
+		free(notify);
+}
+
+static unsigned int vcp_register_notify(struct bt_vcp *vcp,
+					uint16_t value_handle,
+					vcp_notify_t func,
+					void *user_data)
+{
+	struct bt_vcp_notify *notify;
+
+	notify = new0(struct bt_vcp_notify, 1);
+	notify->vcp = vcp;
+	notify->func = func;
+	notify->user_data = user_data;
+
+	notify->id = bt_gatt_client_register_notify(vcp->client,
+						value_handle, vcp_register,
+						vcp_notify, notify,
+						vcp_notify_destroy);
+	if (!notify->id) {
+		DBG(vcp, "Unable to register for notifications");
+		free(notify);
+		return 0;
+	}
+
+	queue_push_tail(vcp->notify, notify);
+
+	return notify->id;
+}
+
 static void foreach_vcs_char(struct gatt_db_attribute *attr, void *user_data)
 {
 	struct bt_vcp *vcp = user_data;
@@ -1006,7 +1075,6 @@ static void foreach_vcs_char(struct gatt_db_attribute *attr, void *user_data)
 	bt_uuid_t uuid, uuid_vstate, uuid_cp, uuid_vflag;
 	struct bt_vcs *vcs;
 
-	DBG("");
 	if (!gatt_db_attribute_get_char_data(attr, NULL, &value_handle,
 						NULL, NULL, &uuid))
 		return;
@@ -1016,7 +1084,7 @@ static void foreach_vcs_char(struct gatt_db_attribute *attr, void *user_data)
 	bt_uuid16_create(&uuid_vflag, VOL_FLAG_CHRC_UUID);
 
 	if (!bt_uuid_cmp(&uuid, &uuid_vstate)) {
-		DBG("VCS Volume state found: handle 0x%04x", value_handle);
+		DBG(vcp, "VCS Vol state found: handle 0x%04x", value_handle);
 
 		vcs = vcp_get_vcs(vcp);
 		if (!vcs || vcs->vs)
@@ -1025,16 +1093,15 @@ static void foreach_vcs_char(struct gatt_db_attribute *attr, void *user_data)
 		vcs->vs = attr;
 
 		vcp_read_value(vcp, value_handle, read_vol_state, vcp);
-		vcp->vstate_id = bt_gatt_client_register_notify(vcp->client,
-						value_handle,
-						vcp_vstate_register,
-						vcp_vstate_notify, vcp, NULL);
+
+		vcp->vstate_id = vcp_register_notify(vcp, value_handle,
+						     vcp_vstate_notify, NULL);
 
 		return;
 	}
 
 	if (!bt_uuid_cmp(&uuid, &uuid_cp)) {
-		DBG("VCS Volume CP found: handle 0x%04x", value_handle);
+		DBG(vcp, "VCS Volume CP found: handle 0x%04x", value_handle);
 
 		vcs = vcp_get_vcs(vcp);
 		if (!vcs || vcs->vol_cp)
@@ -1046,7 +1113,7 @@ static void foreach_vcs_char(struct gatt_db_attribute *attr, void *user_data)
 	}
 
 	if (!bt_uuid_cmp(&uuid, &uuid_vflag)) {
-		DBG("VCS Vol Flaf found: handle 0x%04x", value_handle);
+		DBG(vcp, "VCS Vol Flag found: handle 0x%04x", value_handle);
 
 		vcs = vcp_get_vcs(vcp);
 		if (!vcs || vcs->vf)
@@ -1055,12 +1122,10 @@ static void foreach_vcs_char(struct gatt_db_attribute *attr, void *user_data)
 		vcs->vf = attr;
 
 		vcp_read_value(vcp, value_handle, read_vol_flag, vcp);
-		vcp->vflag_id = bt_gatt_client_register_notify(vcp->client,
-						value_handle,
-						vcp_vflag_register,
-						vcp_vflag_notify, vcp, NULL);
-	}
+		vcp->vflag_id = vcp_register_notify(vcp, value_handle,
+						    vcp_vflag_notify, NULL);
 
+	}
 }
 
 static void foreach_vcs_service(struct gatt_db_attribute *attr,
@@ -1069,7 +1134,6 @@ static void foreach_vcs_service(struct gatt_db_attribute *attr,
 	struct bt_vcp *vcp = user_data;
 	struct bt_vcs *vcs = vcp_get_vcs(vcp);
 
-	DBG("");
 	vcs->service = attr;
 
 	gatt_db_service_set_claimed(attr, true);
diff --git a/src/shared/vcp.h b/src/shared/vcp.h
index 1a999c7776fd..26db5732d19b 100644
--- a/src/shared/vcp.h
+++ b/src/shared/vcp.h
@@ -33,6 +33,8 @@
 
 struct bt_vcp;
 
+typedef void (*bt_vcp_destroy_func_t)(void *user_data);
+typedef void (*bt_vcp_debug_func_t)(const char *str, void *user_data);
 typedef void (*bt_vcp_func_t)(struct bt_vcp *vcp, void *user_data);
 
 struct bt_vcp *bt_vcp_ref(struct bt_vcp *vcp);
@@ -43,6 +45,9 @@ void bt_vcp_add_db(struct gatt_db *db);
 bool bt_vcp_attach(struct bt_vcp *vcp, struct bt_gatt_client *client);
 void bt_vcp_detach(struct bt_vcp *vcp);
 
+bool bt_vcp_set_debug(struct bt_vcp *vcp, bt_vcp_debug_func_t cb,
+			void *user_data, bt_vcp_destroy_func_t destroy);
+
 struct bt_att *bt_vcp_get_att(struct bt_vcp *vcp);
 
 bool bt_vcp_set_user_data(struct bt_vcp *vcp, void *user_data);
-- 
2.25.1