Bluetooth: HFP_HF: Support HF Indicators

Add configuration `CONFIG_BT_HFP_HF_HF_INDICATORS` to enable feature
HF Indicators.

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

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

Add function `bt_hfp_hf_enhanced_safety` to transfer enhanced safety
status.

Add function `bt_hfp_hf_battery` to transfer Remaining level of
Battery.

Send AT command to notify AG the supported HF indicators of HF in SLC
initialization sequence.

Send AT command to get the supported HF indicators of AG in SLC
initialization sequence.

Send AT command to get the enabled/disabled state of generic status
indicators from AG in SLC initialization sequence.

Handle unsolicited result code `+BIND`.

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

Author: lylezhu2012

include/zephyr/bluetooth/classic/hfp_hf.h

@@ -877,6 +877,32 @@ enum hfp_hf_ag_indicators {
  */
 int bt_hfp_hf_indicator_status(struct bt_hfp_hf *hf, uint8_t status);
 
+/** @brief Handsfree HF enable/disable enhanced safety
+ *
+ *  It allows HF to transfer of HF indicator enhanced safety value.
+ *  If @kconfig{CONFIG_BT_HFP_HF_HF_INDICATOR_ENH_SAFETY} is not enabled,
+ *  the error `-ENOTSUP` will be returned if the function called.
+ *
+ *  @param hf HFP HF object.
+ *  @param enable The enhanced safety is enabled/disabled.
+ *
+ *  @return 0 in case of success or negative value in case of error.
+ */
+int bt_hfp_hf_enhanced_safety(struct bt_hfp_hf *hf, bool enable);
+
+/** @brief Handsfree HF remaining battery level
+ *
+ *  It allows HF to transfer of HF indicator remaining battery level value.
+ *  If @kconfig{CONFIG_BT_HFP_HF_HF_INDICATOR_BATTERY} is not enabled,
+ *  the error `-ENOTSUP` will be returned if the function called.
+ *
+ *  @param hf HFP HF object.
+ *  @param level The remaining battery level.
+ *
+ *  @return 0 in case of success or negative value in case of error.
+ */
+int bt_hfp_hf_battery(struct bt_hfp_hf *hf, uint8_t level);
+
 #ifdef __cplusplus
 }
 #endif

subsys/bluetooth/host/classic/Kconfig

@@ -251,6 +251,23 @@ config BT_HFP_HF_VOICE_RECG_TEXT
 	help
 	  This option enables Voice Recognition Text for HFP HF
 
+config BT_HFP_HF_HF_INDICATORS
+	bool "HF Indicators for HFP HF [EXPERIMENTAL]"
+	help
+	  This option enables HF Indicators for HFP HF
+
+config BT_HFP_HF_HF_INDICATOR_ENH_SAFETY
+	bool "HF Indicator Enhanced Safety for HFP HF [EXPERIMENTAL]"
+	select BT_HFP_HF_HF_INDICATORS
+	help
+	  This option enables HF Indicator Enhanced Safety for HFP HF
+
+config BT_HFP_HF_HF_INDICATOR_BATTERY
+	bool "HF Indicator Battery level for HFP HF [EXPERIMENTAL]"
+	select BT_HFP_HF_HF_INDICATORS
+	help
+	  This option enables HF Indicator Battery level for HFP HF
+
 endif # BT_HFP_HF
 
 if BT_HFP_AG

subsys/bluetooth/host/classic/hfp_ag_internal.h

@@ -149,13 +149,6 @@ enum {
 	BT_HFP_AG_CALL_NUM_FLAGS,
 };
 
-/* HFP HF Indicators */
-enum {
-	HFP_HF_ENHANCED_SAFETY_IND = 1, /* Enhanced Safety */
-	HFP_HF_BATTERY_LEVEL_IND = 2,   /* Remaining level of Battery */
-	HFP_HF_IND_MAX
-};
-
 typedef enum __packed {
 	/** Session disconnected */
 	BT_HFP_DISCONNECTED,

subsys/bluetooth/host/classic/hfp_hf.c

@@ -1642,6 +1642,66 @@ static int cnum_handle(struct at_client *hf_at)
 	return 0;
 }
 
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATORS)
+static int bind_handle(struct at_client *hf_at)
+{
+	struct bt_hfp_hf *hf = CONTAINER_OF(hf_at, struct bt_hfp_hf, at);
+	int err;
+	uint32_t index;
+	uint32_t value;
+	uint32_t ind = 0;
+	uint32_t ind_enable = hf->ind_enable;
+
+	err = at_open_list(hf_at);
+	if (!err) {
+		/* It is a list. */
+		while (at_has_next_list(hf_at)) {
+			err = at_get_number(hf_at, &index);
+			if (err) {
+				LOG_INF("Cannot get indicator");
+				goto failed;
+			}
+
+			ind |= BIT(index);
+		}
+
+		if (at_close_list(hf_at) < 0) {
+			LOG_ERR("Could not get close list");
+			goto failed;
+		}
+
+		hf->ag_ind = ind;
+		return 0;
+	}
+
+	err = at_get_number(hf_at, &index);
+	if (err) {
+		LOG_INF("Cannot get indicator");
+		goto failed;
+	}
+
+	err = at_get_number(hf_at, &value);
+	if (err) {
+		LOG_INF("Cannot get status");
+		goto failed;
+	}
+
+	if (!value) {
+		ind_enable &= ~BIT(index);
+	} else {
+		ind_enable |= BIT(index);
+	}
+
+	hf->ind_enable = ind_enable;
+	return 0;
+
+failed:
+	LOG_ERR("Error on AT+BIND response");
+	hf_slc_error(hf_at);
+	return -EINVAL;
+}
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
+
 static const struct unsolicited {
 	const char *cmd;
 	enum at_cmd_type type;
@@ -1672,6 +1732,9 @@ static const struct unsolicited {
 	{ "BVRA", AT_CMD_TYPE_UNSOLICITED, bvra_handle },
 #endif /* CONFIG_BT_HFP_HF_VOICE_RECG */
 	{ "CNUM", AT_CMD_TYPE_UNSOLICITED, cnum_handle },
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATORS)
+	{ "BIND", AT_CMD_TYPE_UNSOLICITED, bind_handle },
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
 };
 
 static const struct unsolicited *hfp_hf_unsol_lookup(struct at_client *hf_at)
@@ -1913,6 +1976,51 @@ static void slc_completed(struct at_client *hf_at)
 	}
 }
 
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATORS)
+static int send_at_bind_status(struct bt_hfp_hf *hf, at_finish_cb_t cb)
+{
+	return hfp_hf_send_cmd(hf, NULL, cb, "AT+BIND?");
+}
+
+static int send_at_bind_hf_supported(struct bt_hfp_hf *hf, at_finish_cb_t cb)
+{
+	char buffer[4];
+	char *bind;
+
+	hf->hf_ind = 0;
+
+	bind = &buffer[0];
+	if (IS_ENABLED(CONFIG_BT_HFP_HF_HF_INDICATOR_ENH_SAFETY)) {
+		*bind = '0' + HFP_HF_ENHANCED_SAFETY_IND;
+		bind++;
+		*bind = ',';
+		bind++;
+		hf->hf_ind |= BIT(HFP_HF_ENHANCED_SAFETY_IND);
+	}
+
+	if (IS_ENABLED(CONFIG_BT_HFP_HF_HF_INDICATOR_BATTERY)) {
+		*bind = '0' + HFP_HF_BATTERY_LEVEL_IND;
+		bind++;
+		*bind = ',';
+		bind++;
+		hf->hf_ind |= BIT(HFP_HF_BATTERY_LEVEL_IND);
+	}
+
+	if (bind <= &buffer[0]) {
+		return -EINVAL;
+	}
+
+	bind--;
+	*bind = '\0';
+	return hfp_hf_send_cmd(hf, NULL, cb, "AT+BIND=%s", buffer);
+}
+
+static int send_at_bind_supported(struct bt_hfp_hf *hf, at_finish_cb_t cb)
+{
+	return hfp_hf_send_cmd(hf, NULL, cb, "AT+BIND=?");
+}
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
+
 #if defined(CONFIG_BT_HFP_HF_3WAY_CALL)
 static int send_at_chld_supported(struct bt_hfp_hf *hf, at_finish_cb_t cb)
 {
@@ -1989,6 +2097,11 @@ static struct slc_init
 #if defined(CONFIG_BT_HFP_HF_3WAY_CALL)
 	{send_at_chld_supported, true, BT_HFP_AG_FEATURE_3WAY_CALL},
 #endif /* CONFIG_BT_HFP_HF_3WAY_CALL */
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATORS)
+	{send_at_bind_hf_supported, true, BT_HFP_AG_FEATURE_HF_IND},
+	{send_at_bind_supported, true, BT_HFP_AG_FEATURE_HF_IND},
+	{send_at_bind_status, true, BT_HFP_AG_FEATURE_HF_IND},
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
 };
 
 static int slc_init_start(struct bt_hfp_hf *hf);
@@ -2512,6 +2625,115 @@ int bt_hfp_hf_indicator_status(struct bt_hfp_hf *hf, uint8_t status)
 	return err;
 }
 
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATOR_ENH_SAFETY)
+static int biev_enh_safety_finish(struct at_client *hf_at,
+		   enum at_result result, enum at_cme cme_err)
+{
+	struct bt_hfp_hf *hf = CONTAINER_OF(hf_at, struct bt_hfp_hf, at);
+
+	LOG_DBG("AT+BIEV (result %d) on %p", result, hf);
+
+	return 0;
+}
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATOR_ENH_SAFETY */
+
+int bt_hfp_hf_enhanced_safety(struct bt_hfp_hf *hf, bool enable)
+{
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATOR_ENH_SAFETY)
+	int err;
+
+	LOG_DBG("");
+
+	if (!hf) {
+		LOG_ERR("No HF connection found");
+		return -ENOTCONN;
+	}
+
+	if (!atomic_test_bit(hf->flags, BT_HFP_HF_FLAG_CONNECTED)) {
+		LOG_ERR("SLC is not established on %p", hf);
+		return -ENOTCONN;
+	}
+
+	if (!((hf->hf_ind & BIT(HFP_HF_ENHANCED_SAFETY_IND)) &&
+		(hf->ag_ind & BIT(HFP_HF_ENHANCED_SAFETY_IND)))) {
+		LOG_ERR("The indicator is unsupported");
+		return -ENOTSUP;
+	}
+
+	if (!(hf->ind_enable & BIT(HFP_HF_ENHANCED_SAFETY_IND))) {
+		LOG_ERR("The indicator is disabled");
+		return -EINVAL;
+	}
+
+	err = hfp_hf_send_cmd(hf, NULL, biev_enh_safety_finish, "AT+BIEV=%d,%d",
+		HFP_HF_ENHANCED_SAFETY_IND, enable ? 1 : 0);
+	if (err < 0) {
+		LOG_ERR("Fail to transfer enhanced safety value on %p", hf);
+	}
+
+	return err;
+#else
+	return -ENOTSUP;
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATOR_ENH_SAFETY */
+}
+
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATOR_BATTERY)
+static int biev_battery_finish(struct at_client *hf_at,
+		   enum at_result result, enum at_cme cme_err)
+{
+	struct bt_hfp_hf *hf = CONTAINER_OF(hf_at, struct bt_hfp_hf, at);
+
+	LOG_DBG("AT+BIEV (result %d) on %p", result, hf);
+
+	return 0;
+}
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATOR_BATTERY */
+
+int bt_hfp_hf_battery(struct bt_hfp_hf *hf, uint8_t level)
+{
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATOR_BATTERY)
+	int err;
+
+	LOG_DBG("");
+
+	if (!hf) {
+		LOG_ERR("No HF connection found");
+		return -ENOTCONN;
+	}
+
+	if (!atomic_test_bit(hf->flags, BT_HFP_HF_FLAG_CONNECTED)) {
+		LOG_ERR("SLC is not established on %p", hf);
+		return -ENOTCONN;
+	}
+
+	if (!((hf->hf_ind & BIT(HFP_HF_BATTERY_LEVEL_IND)) &&
+		(hf->ag_ind & BIT(HFP_HF_BATTERY_LEVEL_IND)))) {
+		LOG_ERR("The indicator is unsupported");
+		return -ENOTSUP;
+	}
+
+	if (!(hf->ind_enable & BIT(HFP_HF_BATTERY_LEVEL_IND))) {
+		LOG_ERR("The indicator is disabled");
+		return -EINVAL;
+	}
+
+	if (!IS_VALID_BATTERY_LEVEL(level)) {
+		LOG_ERR("Invalid battery level %d", level);
+		return -EINVAL;
+	}
+
+	err = hfp_hf_send_cmd(hf, NULL, biev_battery_finish, "AT+BIEV=%d,%d",
+		HFP_HF_BATTERY_LEVEL_IND, level);
+	if (err < 0) {
+		LOG_ERR("Fail to transfer remaining battery level on %p", hf);
+	}
+
+	return err;
+#else
+	return -ENOTSUP;
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATOR_BATTERY */
+}
+
 static int ata_finish(struct at_client *hf_at, enum at_result result,
 		   enum at_cme cme_err)
 {

subsys/bluetooth/host/classic/hfp_internal.h

@@ -126,6 +126,12 @@
 #define BT_HFP_HF_SDP_FEATURE_VOICE_RECG_TEXT_ENABLE 0
 #endif /* CONFIG_BT_HFP_HF_VOICE_RECG_TEXT */
 
+#if defined(CONFIG_BT_HFP_HF_HF_INDICATORS)
+#define BT_HFP_HF_FEATURE_HF_IND_ENABLE BT_HFP_HF_FEATURE_HF_IND
+#else
+#define BT_HFP_HF_FEATURE_HF_IND_ENABLE 0
+#endif /* CONFIG_BT_HFP_HF_HF_INDICATORS */
+
 /* HFP HF Supported features */
 #define BT_HFP_HF_SUPPORTED_FEATURES (\
 	BT_HFP_HF_FEATURE_CLI_ENABLE | \
@@ -137,7 +143,8 @@
 	BT_HFP_HF_FEATURE_ECC_ENABLE | \
 	BT_HFP_HF_FEATURE_VOICE_RECG_ENABLE | \
 	BT_HFP_HF_FEATURE_ENH_VOICE_RECG_ENABLE | \
-	BT_HFP_HF_FEATURE_VOICE_RECG_TEXT_ENABLE)
+	BT_HFP_HF_FEATURE_VOICE_RECG_TEXT_ENABLE | \
+	BT_HFP_HF_FEATURE_HF_IND_ENABLE)
 
 /* HFP HF Supported features in SDP */
 #define BT_HFP_HF_SDP_SUPPORTED_FEATURES (\
@@ -245,6 +252,10 @@ struct bt_hfp_hf {
 	uint8_t vgs;
 	int8_t ind_table[HF_MAX_AG_INDICATORS];
 
+	uint32_t hf_ind;
+	uint32_t ag_ind;
+	uint32_t ind_enable;
+
 	/* AT command initialization indicator */
 	uint8_t cmd_init_seq;
 
@@ -350,3 +361,12 @@ struct bt_hfp_hf {
 
 #define IS_VALID_DTMF(c) ((((c) >= '0') && ((c) <= '9')) || \
 	(((c) >= 'A') && ((c) <= 'D')) || ((c) == '#') || ((c) == '*'))
+
+/* HFP HF Indicators */
+enum {
+	HFP_HF_ENHANCED_SAFETY_IND = 1, /* Enhanced Safety */
+	HFP_HF_BATTERY_LEVEL_IND = 2,   /* Remaining level of Battery */
+	HFP_HF_IND_MAX
+};
+
+#define IS_VALID_BATTERY_LEVEL(level) (((level) >= 0) && ((level) <= 100))