Bluetooth: Classic: HFP_AG: Update the callback `sco_disconnected()`

Change the arguments of HFP AG callback `sco_disconnected()` to SCO
conn and disconnection reason.

Signed-off-by: Lyle Zhu <lyle.zhu@nxp.com>

doc/releases/migration-guide-4.2.rst

@@ -227,6 +227,13 @@ Bluetooth Host
   each role may be different. Any existing uses/checks for ``BT_ISO_CHAN_TYPE_CONNECTED``
   can be replaced with an ``||`` of the two. (:github:`75549`)
 
+Bluetooth Classic
+=================
+
+* The parameters of HFP AG callback ``sco_disconnected`` of the struct :c:struct:`bt_hfp_ag_cb`
+  have been changed to SCO connection object ``struct bt_conn *sco_conn`` and the disconnection
+  reason of the SCO connection ``uint8_t reason``.
+
 Networking
 **********
 

include/zephyr/bluetooth/classic/hfp_ag.h

@@ -111,10 +111,10 @@ struct bt_hfp_ag_cb {
 	 *  If this callback is provided it will be called whenever the
 	 *  SCO/eSCO connection gets disconnected.
 	 *
-	 *  @param ag HFP AG object.
-	 *  @param sco_conn SCO/eSCO Connection object.
+	 *  @param conn SCO/eSCO Connection object.
+	 *  @param reason BT_HCI_ERR_* reason for the disconnection.
 	 */
-	void (*sco_disconnected)(struct bt_hfp_ag *ag);
+	void (*sco_disconnected)(struct bt_conn *sco_conn, uint8_t reason);
 
 	/** HF memory dialing request Callback
 	 *

samples/bluetooth/handsfree_ag/src/main.c

@@ -63,9 +63,9 @@ static void ag_sco_connected(struct bt_hfp_ag *ag, struct bt_conn *sco_conn)
 	printk("HFP AG SCO connected!\n");
 }
 
-static void ag_sco_disconnected(struct bt_hfp_ag *ag)
+static void ag_sco_disconnected(struct bt_conn *sco_conn, uint8_t reason)
 {
-	printk("HFP AG SCO disconnected!\n");
+	printk("HFP AG SCO disconnected %u!\n", reason);
 }
 
 static void ag_ringing(struct bt_hfp_ag_call *call, bool in_band)

subsys/bluetooth/host/classic/hfp_ag.c

@@ -2029,8 +2029,8 @@ static void hfp_ag_sco_disconnected(struct bt_sco_chan *chan, uint8_t reason)
 
 	call = get_call_with_flag(ag, BT_HFP_AG_CALL_OPEN_SCO, true);
 
-	if ((bt_ag) && bt_ag->sco_disconnected) {
-		bt_ag->sco_disconnected(ag);
+	if ((bt_ag != NULL) && bt_ag->sco_disconnected) {
+		bt_ag->sco_disconnected(chan->sco, reason);
 	}
 
 	if (!call) {

subsys/bluetooth/host/classic/shell/hfp.c

@@ -73,14 +73,26 @@ static void hf_disconnected(struct bt_hfp_hf *hf)
 
 static void hf_sco_connected(struct bt_hfp_hf *hf, struct bt_conn *sco_conn)
 {
-	bt_shell_print("HF SCO connected");
-	hf_sco_conn = sco_conn;
+	bt_shell_print("HF SCO connected %p", sco_conn);
+
+	if (hf_sco_conn != NULL) {
+		bt_shell_warn("HF SCO conn %p exists", hf_sco_conn);
+		return;
+	}
+
+	hf_sco_conn = bt_conn_ref(sco_conn);
 }
 
 static void hf_sco_disconnected(struct bt_conn *sco_conn, uint8_t reason)
 {
-	bt_shell_print("HF SCO disconnected");
-	hf_sco_conn = NULL;
+	bt_shell_print("HF SCO disconnected %p (reason %u)", sco_conn, reason);
+
+	if (hf_sco_conn == sco_conn) {
+		bt_conn_unref(hf_sco_conn);
+		hf_sco_conn = NULL;
+	} else {
+		bt_shell_warn("Unknown SCO disconnected (%p != %p)", hf_sco_conn, sco_conn);
+	}
 }
 
 void hf_service(struct bt_hfp_hf *hf, uint32_t value)
@@ -998,14 +1010,26 @@ static void ag_disconnected(struct bt_hfp_ag *ag)
 
 static void ag_sco_connected(struct bt_hfp_ag *ag, struct bt_conn *sco_conn)
 {
-	bt_shell_print("ag sco connected");
-	hfp_ag_sco_conn = sco_conn;
+	bt_shell_print("AG SCO connected %p", sco_conn);
+
+	if (hfp_ag_sco_conn != NULL) {
+		bt_shell_warn("AG SCO conn %p exists", hfp_ag_sco_conn);
+		return;
+	}
+
+	hfp_ag_sco_conn = bt_conn_ref(sco_conn);
 }
 
-static void ag_sco_disconnected(struct bt_hfp_ag *ag)
+static void ag_sco_disconnected(struct bt_conn *sco_conn, uint8_t reason)
 {
-	bt_shell_print("ag sco disconnected");
-	hfp_ag_sco_conn = NULL;
+	bt_shell_print("AG SCO disconnected %p (reason %u)", sco_conn, reason);
+
+	if (hfp_ag_sco_conn == sco_conn) {
+		bt_conn_unref(hfp_ag_sco_conn);
+		hfp_ag_sco_conn = NULL;
+	} else {
+		bt_shell_warn("Unknown SCO disconnected (%p != %p)", hfp_ag_sco_conn, sco_conn);
+	}
 }
 
 static int ag_memory_dial(struct bt_hfp_ag *ag, const char *location, char **number)