Bluetooth: HFP_AG: Support HF Indicators

Add configuration `CONFIG_BT_HFP_AG_HF_INDICATORS` to enable feature
HF Indicators.

Add configuration `CONFIG_BT_HFP_AG_HF_INDICATOR_ENH_SAFETY` to
support HF indicator `Enhanced Safety`.

Add configuration `CONFIG_BT_HFP_AG_HF_INDICATOR_BATTERY` to support
HF indicator `Remaining level of Battery`.

Add function `bt_hfp_ag_hf_indicator` to activate/deactivate HF
indicator.

Optimize the handle of AT command `AT+BIND`.

Handle AT command `AT+BIEV`.

Add callback `hf_indicator_value` to notify the value of HF indicator.

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

Author: lylezhu2012

include/zephyr/bluetooth/classic/hfp_ag.h

@@ -71,6 +71,12 @@ struct bt_hfp_ag_call;
 typedef int (*bt_hfp_ag_query_subscriber_func_t)(struct bt_hfp_ag *ag, char *number, uint8_t type,
 						 uint8_t service);
 
+/* HF indicators */
+enum hfp_ag_hf_indicators {
+	HFP_AG_ENHANCED_SAFETY_IND = 1, /* Enhanced Safety */
+	HFP_AG_BATTERY_LEVEL_IND = 2,   /* Remaining level of Battery */
+};
+
 /** @brief HFP profile AG application callback */
 struct bt_hfp_ag_cb {
 	/** HF AG connected callback to application
@@ -388,6 +394,20 @@ struct bt_hfp_ag_cb {
 	 *  @return 0 in case of success or negative value in case of error.
 	 */
 	int (*subscriber_number)(struct bt_hfp_ag *ag, bt_hfp_ag_query_subscriber_func_t func);
+
+	/** HF indicator value callback
+	 *
+	 *  If this callback is provided it will be called whenever the
+	 *  AT command `AT+BIEV` is received.
+	 *  If @kconfig{CONFIG_BT_HFP_AG_HF_INDICATORS} is not enabled,
+	 *  the callback will not be notified.
+	 *
+	 *  @param ag HFP AG object.
+	 *  @param indicator HF indicator
+	 *  @param value The value of specific indicator
+	 */
+	void (*hf_indicator_value)(struct bt_hfp_ag *ag, enum hfp_ag_hf_indicators indicator,
+				   uint32_t value);
 };
 
 /** @brief Register HFP AG profile
@@ -747,6 +767,29 @@ int bt_hfp_ag_battery_level(struct bt_hfp_ag *ag, uint8_t level);
  */
 int bt_hfp_ag_service_availability(struct bt_hfp_ag *ag, bool available);
 
+/** @brief Activate/deactivate HF indicator
+ *
+ *  It allows HF to issue the +BIND unsolicited result code to
+ *  activate/deactivate of the AG’s supported HF Indicators.
+ *  The indicator of supported indicators can be activated/deactivated
+ *  are defined in `enum hfp_ag_hf_indicators`.
+ *  `BT_HFP_AG_HF_INDICATOR_ENH_SAFETY` is used to support
+ *  `Enhanced Safety`. Only the configuration has been enabled, the
+ *  `indicator` can be HFP_AG_ENHANCED_SAFETY_IND.
+ *  `BT_HFP_AG_HF_INDICATOR_BATTERY` is used to support
+ *  `Remaining level of Battery`. Only the configuration has been
+ *  enabled, the `indicator` can be HFP_AG_BATTERY_LEVEL_IND.
+ *  If @kconfig{CONFIG_BT_HFP_HF_HF_INDICATORS} is not enabled, the error
+ *  `-ENOTSUP` will be returned if the function called.
+ *
+ *  @param ag HFP AG object.
+ *  @param indicator The indicator of the AG’s supported HF Indicators.
+ *  @param enable enable/disable specific HF Indicator.
+ *
+ *  @return 0 in case of success or negative value in case of error.
+ */
+int bt_hfp_ag_hf_indicator(struct bt_hfp_ag *ag, enum hfp_ag_hf_indicators indicator, bool enable);
+
 #ifdef __cplusplus
 }
 #endif

subsys/bluetooth/host/classic/Kconfig

@@ -396,6 +396,23 @@ config BT_HFP_AG_VOICE_TAG
 	help
 	  This option enables Attach a phone number for a voice tag for HFP AG
 
+config BT_HFP_AG_HF_INDICATORS
+	bool "HF Indicators for HFP AG [EXPERIMENTAL]"
+	help
+	  This option enables HF Indicators for HFP AG
+
+config BT_HFP_AG_HF_INDICATOR_ENH_SAFETY
+	bool "HF Indicator Enhanced Safety for HFP AG [EXPERIMENTAL]"
+	select BT_HFP_AG_HF_INDICATORS
+	help
+	  This option enables HF Indicator Enhanced Safety for HFP AG
+
+config BT_HFP_AG_HF_INDICATOR_BATTERY
+	bool "HF Indicator Battery level for HFP AG [EXPERIMENTAL]"
+	select BT_HFP_AG_HF_INDICATORS
+	help
+	  This option enables HF Indicator Battery level for HFP AG
+
 endif # BT_HFP_AG
 
 config BT_AVDTP

subsys/bluetooth/host/classic/hfp_ag.c

@@ -1508,6 +1508,7 @@ static int bt_hfp_ag_bind_handler(struct bt_hfp_ag *ag, struct net_buf *buf)
 {
 	uint32_t indicator;
 	uint32_t hf_indicators = 0U;
+	uint32_t supported_indicators = 0U;
 	int err;
 	char *data;
 	uint32_t len;
@@ -1526,20 +1527,27 @@ static int bt_hfp_ag_bind_handler(struct bt_hfp_ag *ag, struct net_buf *buf)
 		}
 
 		hfp_ag_lock(ag);
-		hf_indicators = ag->hf_indicators_of_hf & ag->hf_indicators_of_ag;
+		hf_indicators = ag->hf_indicators;
+		supported_indicators = ag->hf_indicators_of_ag & ag->hf_indicators_of_hf;
 		hfp_ag_unlock(ag);
-		len = (sizeof(hf_indicators) * 8) > HFP_HF_IND_MAX ? HFP_HF_IND_MAX
-								   : (sizeof(hf_indicators) * 8);
+		len = MIN(NUM_BITS(sizeof(supported_indicators)), HFP_HF_IND_MAX);
 		for (int i = 1; i < len; i++) {
-			if (BIT(i) & hf_indicators) {
-				err = hfp_ag_send_data(ag, NULL, NULL, "\r\n+BIND:%d,%d\r\n", i, 1);
-			} else {
-				err = hfp_ag_send_data(ag, NULL, NULL, "\r\n+BIND:%d,%d\r\n", i, 0);
+			bool enabled;
+
+			if (!(BIT(i) & supported_indicators)) {
+				continue;
 			}
-			if (err < 0) {
+
+			enabled = BIT(i) & hf_indicators;
+			err = hfp_ag_send_data(ag, NULL, NULL, "\r\n+BIND:%d,%d\r\n", i,
+				enabled ? 1 : 0);
+			if (err) {
 				return err;
 			}
-			if (hf_indicators == 0) {
+
+			supported_indicators &= ~BIT(i);
+
+			if (!supported_indicators) {
 				break;
 			}
 		}
@@ -1561,12 +1569,11 @@ static int bt_hfp_ag_bind_handler(struct bt_hfp_ag *ag, struct net_buf *buf)
 		hfp_ag_lock(ag);
 		hf_indicators = ag->hf_indicators_of_ag;
 		hfp_ag_unlock(ag);
-		len = (sizeof(hf_indicators) * 8) > HFP_HF_IND_MAX ? HFP_HF_IND_MAX
-								   : (sizeof(hf_indicators) * 8);
+		len = MIN(NUM_BITS(sizeof(hf_indicators)), HFP_HF_IND_MAX);
 		for (int i = 1; (i < len) && (hf_indicators != 0); i++) {
 			if (BIT(i) & hf_indicators) {
 				int length = snprintk(
-					data, (char *)&ag->buffer[HF_MAX_BUF_LEN - 1] - data - 3,
+					data, (char *)&ag->buffer[HF_MAX_BUF_LEN - 1] - data - 2,
 					"%d", i);
 				data += length;
 				hf_indicators &= ~BIT(i);
@@ -1578,8 +1585,6 @@ static int bt_hfp_ag_bind_handler(struct bt_hfp_ag *ag, struct net_buf *buf)
 		}
 		*data = ')';
 		data++;
-		*data = '\r';
-		data++;
 		*data = '\0';
 		data++;
 
@@ -1599,7 +1604,7 @@ static int bt_hfp_ag_bind_handler(struct bt_hfp_ag *ag, struct net_buf *buf)
 			}
 		}
 
-		if (indicator < (sizeof(hf_indicators) * 8)) {
+		if (indicator < NUM_BITS(sizeof(hf_indicators))) {
 			hf_indicators |= BIT(indicator);
 		}
 	}
@@ -3089,6 +3094,47 @@ static int bt_hfp_ag_cnum_handler(struct bt_hfp_ag *ag, struct net_buf *buf)
 	return 0;
 }
 
+static int bt_hfp_ag_biev_handler(struct bt_hfp_ag *ag, struct net_buf *buf)
+{
+	uint32_t indicator;
+	uint32_t value;
+
+	if (!is_char(buf, '=')) {
+		return -ENOTSUP;
+	}
+
+	if (get_number(buf, &indicator)) {
+		return -ENOTSUP;
+	}
+
+	if (!is_char(buf, ',')) {
+		return -ENOTSUP;
+	}
+
+	if (get_number(buf, &value)) {
+		return -ENOTSUP;
+	}
+
+	if (!is_char(buf, '\r')) {
+		return -ENOTSUP;
+	}
+
+	hfp_ag_lock(ag);
+	if (!(ag->hf_indicators_of_ag & BIT(indicator))) {
+		hfp_ag_unlock(ag);
+		return -ENOTSUP;
+	}
+	hfp_ag_unlock(ag);
+
+#if defined(CONFIG_BT_HFP_AG_HF_INDICATORS)
+	if (bt_ag && bt_ag->hf_indicator_value) {
+		bt_ag->hf_indicator_value(ag, indicator, value);
+	}
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
+
+	return 0;
+}
+
 static struct bt_hfp_ag_at_cmd_handler cmd_handlers[] = {
 	{"AT+BRSF", bt_hfp_ag_brsf_handler}, {"AT+BAC", bt_hfp_ag_bac_handler},
 	{"AT+CIND", bt_hfp_ag_cind_handler}, {"AT+CMER", bt_hfp_ag_cmer_handler},
@@ -3103,6 +3149,7 @@ static struct bt_hfp_ag_at_cmd_handler cmd_handlers[] = {
 	{"AT+BTRH", bt_hfp_ag_btrh_handler}, {"AT+CCWA", bt_hfp_ag_ccwa_handler},
 	{"AT+BVRA", bt_hfp_ag_bvra_handler}, {"AT+BINP", bt_hfp_ag_binp_handler},
 	{"AT+VTS", bt_hfp_ag_vts_handler},   {"AT+CNUM", bt_hfp_ag_cnum_handler},
+	{"AT+BIEV", bt_hfp_ag_biev_handler},
 };
 
 static void hfp_ag_connected(struct bt_rfcomm_dlc *dlc)
@@ -3492,6 +3539,17 @@ int bt_hfp_ag_connect(struct bt_conn *conn, struct bt_hfp_ag **ag, uint8_t chann
 		/* Set the supported features*/
 		_ag->ag_features = BT_HFP_AG_SUPPORTED_FEATURES;
 
+		/* Support HF indicators */
+		if (IS_ENABLED(CONFIG_BT_HFP_AG_HF_INDICATOR_ENH_SAFETY)) {
+			_ag->hf_indicators_of_ag |= BIT(HFP_HF_ENHANCED_SAFETY_IND);
+		}
+
+		if (IS_ENABLED(CONFIG_BT_HFP_AG_HF_INDICATOR_BATTERY)) {
+			_ag->hf_indicators_of_ag |= BIT(HFP_HF_BATTERY_LEVEL_IND);
+		}
+
+		_ag->hf_indicators = _ag->hf_indicators_of_ag;
+
 		/* If supported codec ids cannot be notified, disable codec negotiation. */
 		if (!(bt_ag && bt_ag->codec)) {
 			_ag->ag_features &= ~BT_HFP_AG_FEATURE_CODEC_NEG;
@@ -4730,3 +4788,49 @@ int bt_hfp_ag_service_availability(struct bt_hfp_ag *ag, bool available)
 
 	return err;
 }
+
+int bt_hfp_ag_hf_indicator(struct bt_hfp_ag *ag, enum hfp_ag_hf_indicators indicator, bool enable)
+{
+#if defined(CONFIG_BT_HFP_AG_HF_INDICATORS)
+	int err;
+	uint32_t supported_indicators;
+
+	LOG_DBG("");
+
+	if (ag == NULL) {
+		return -EINVAL;
+	}
+
+	hfp_ag_lock(ag);
+	if (ag->state != BT_HFP_CONNECTED) {
+		hfp_ag_unlock(ag);
+		return -ENOTCONN;
+	}
+
+	supported_indicators = ag->hf_indicators_of_ag & ag->hf_indicators_of_hf;
+	hfp_ag_unlock(ag);
+
+	if (!(supported_indicators & BIT(indicator))) {
+		LOG_ERR("Unsupported indicator %d", indicator);
+		return -ENOTSUP;
+	}
+
+	hfp_ag_lock(ag);
+	if (enable) {
+		ag->hf_indicators |= BIT(indicator);
+	} else {
+		ag->hf_indicators &= ~BIT(indicator);
+	}
+	hfp_ag_unlock(ag);
+
+	err = hfp_ag_send_data(ag, NULL, NULL, "\r\n+BIND:%d,%d\r\n",
+		indicator, enable ? 1  : 0);
+	if (err) {
+		LOG_ERR("Fail to update registration status of indicator:(%d)", err);
+	}
+
+	return err;
+#else
+	return -ENOTSUP;
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
+}

subsys/bluetooth/host/classic/hfp_ag_internal.h

@@ -92,6 +92,12 @@
 #define BT_HFP_AG_SDP_FEATURE_VOICE_TAG_ENABLE 0
 #endif /* CONFIG_BT_HFP_AG_VOICE_TAG */
 
+#if defined(CONFIG_BT_HFP_AG_HF_INDICATORS)
+#define BT_HFP_AG_FEATURE_HF_IND_ENABLE BT_HFP_AG_FEATURE_HF_IND
+#else
+#define BT_HFP_AG_FEATURE_HF_IND_ENABLE 0
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
+
 /* HFP AG Supported features */
 #define BT_HFP_AG_SUPPORTED_FEATURES (\
 	BT_HFP_AG_FEATURE_3WAY_CALL_ENABLE | \
@@ -104,7 +110,8 @@
 	BT_HFP_AG_FEATURE_VOICE_RECG_ENABLE | \
 	BT_HFP_AG_FEATURE_ENH_VOICE_RECG_ENABLE | \
 	BT_HFP_AG_FEATURE_VOICE_RECG_TEXT_ENABLE | \
-	BT_HFP_AG_FEATURE_VOICE_TAG_ENABLE)
+	BT_HFP_AG_FEATURE_VOICE_TAG_ENABLE | \
+	BT_HFP_AG_FEATURE_HF_IND_ENABLE)
 
 /* HFP AG Supported features in SDP */
 #define BT_HFP_AG_SDP_SUPPORTED_FEATURES (\
@@ -221,7 +228,7 @@ struct bt_hfp_ag {
 	/* HF Indicators */
 	uint32_t hf_indicators_of_ag;
 	uint32_t hf_indicators_of_hf;
-	uint8_t hf_indicator_value[HFP_HF_IND_MAX];
+	uint32_t hf_indicators;
 
 	/* operator */
 	uint8_t mode;