Bluetooth: HFP_AG: Set signal strength

Add a function `bt_hfp_ag_signal_strength` to set the signal strength.

Signed-off-by: Lyle Zhu <[email protected]>

Author: lylezhu2012

include/zephyr/bluetooth/classic/hfp_ag.h

@@ -703,6 +703,17 @@ int bt_hfp_ag_vre_state(struct bt_hfp_ag *ag, uint8_t state);
 int bt_hfp_ag_vre_textual_representation(struct bt_hfp_ag *ag, uint8_t state, const char *id,
 					 uint8_t type, uint8_t operation, const char *text);
 
+/** @brief Set signal strength
+ *
+ *  Set signal strength.
+ *
+ *  @param ag HFP AG object.
+ *  @param strength Signal strength.
+ *
+ *  @return 0 in case of success or negative value in case of error.
+ */
+int bt_hfp_ag_signal_strength(struct bt_hfp_ag *ag, uint8_t strength);
+
 #ifdef __cplusplus
 }
 #endif

subsys/bluetooth/host/classic/hfp_ag.c

@@ -376,6 +376,14 @@ static int hfp_ag_update_indicator(struct bt_hfp_ag *ag, enum bt_hfp_ag_indicato
 	int err;
 	uint8_t old_value;
 
+	if (index >= BT_HFP_AG_IND_MAX) {
+		return -EINVAL;
+	}
+
+	if ((ag_ind[index].max < value) || (ag_ind[index].min > value)) {
+		return -EINVAL;
+	}
+
 	hfp_ag_lock(ag);
 	old_value = ag->indicator_value[index];
 	if (value == old_value) {
@@ -4612,3 +4620,29 @@ int bt_hfp_ag_vre_textual_representation(struct bt_hfp_ag *ag, uint8_t state, co
 	return -ENOTSUP;
 #endif /* CONFIG_BT_HFP_AG_VOICE_RECG_TEXT */
 }
+
+int bt_hfp_ag_signal_strength(struct bt_hfp_ag *ag, uint8_t strength)
+{
+	int err;
+
+	LOG_DBG("");
+
+	if (ag == NULL) {
+		return -EINVAL;
+	}
+
+	hfp_ag_lock(ag);
+	if (ag->state != BT_HFP_CONNECTED) {
+		hfp_ag_unlock(ag);
+		return -ENOTCONN;
+	}
+	hfp_ag_unlock(ag);
+
+	err = hfp_ag_update_indicator(ag, BT_HFP_AG_SIGNAL_IND, strength,
+						NULL, NULL);
+	if (err) {
+		LOG_ERR("Fail to set signal strength err :(%d)", err);
+	}
+
+	return err;
+}