Bluetooth: host: Add DF to initalization sequence

Add Direction Finding to host initialization sequence.
It allows to get information about Direction finding
optional CTE settings supported by controller.

Signed-off-by: Piotr Pryga <piotr.pryga@nordicsemi.no>

include/bluetooth/hci.h

@@ -185,6 +185,8 @@ struct bt_hci_cmd_hdr {
 						BT_LE_FEAT_BIT_EXT_ADV)
 #define BT_FEAT_LE_EXT_PER_ADV(feat)            BT_LE_FEAT_TEST(feat, \
 						BT_LE_FEAT_BIT_PER_ADV)
+#define BT_FEAT_LE_CONNECTIONLESS_CTE_TX(feat)  BT_LE_FEAT_TEST(feat, \
+						BT_LE_FEAT_BIT_CONNECTIONLESS_CTE_TX)
 #define BT_FEAT_LE_PAST_SEND(feat)              BT_LE_FEAT_TEST(feat, \
 						BT_LE_FEAT_BIT_PAST_SEND)
 #define BT_FEAT_LE_PAST_RECV(feat)              BT_LE_FEAT_TEST(feat, \

subsys/bluetooth/host/Kconfig

@@ -608,6 +608,12 @@ config BT_DF
 	  It will allow to: get information about antennae, configure
 	  Constant Tone Extension, transmit CTE and sample incoming CTE.
 
+config BT_DEBUG_DF
+	bool "Bluetooth Direction Finding debug"
+	depends on BT_DF
+	help
+	  This option enables debug support for Bluetooth Direction Finding
+
 endif # BT_HCI_HOST
 
 config BT_ECC

subsys/bluetooth/host/direction.c

@@ -7,15 +7,40 @@
 #include <assert.h>
 
 #include <bluetooth/hci.h>
+#include <bluetooth/l2cap.h>
 #include <bluetooth/conn.h>
 #include <sys/byteorder.h>
 
 #include "conn_internal.h"
+#include "direction_internal.h"
 
-#define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_DEBUG_HCI_CORE)
+#define BT_DBG_ENABLED IS_ENABLED(CONFIG_BT_DEBUG_DF)
 #define LOG_MODULE_NAME bt_df
 #include "common/log.h"
 
+/* @brief Antenna information for LE Direction Finding */
+struct bt_le_df_ant_info {
+	/* Bitfield holding optional switching and sampling rates */
+	uint8_t switch_sample_rates;
+	/* Available antennae number */
+	uint8_t num_ant;
+	/* Maximum supported antennae switching pattern length */
+	uint8_t max_switch_pattern_len;
+	/* Maximum length of CTE in 8[us] units */
+	uint8_t max_cte_len;
+};
+
+static struct bt_le_df_ant_info df_ant_info;
+
+#define DF_SUPP_TEST(feat, n)                   ((feat) & BIT((n)))
+
+#define DF_AOD_TX_1US_SUPPORT(supp)             (DF_SUPP_TEST(supp, \
+						BT_HCI_LE_1US_AOD_TX))
+#define DF_AOD_RX_1US_SUPPORT(supp)             (DF_SUPP_TEST(supp, \
+						BT_HCI_LE_1US_AOD_RX))
+#define DF_AOA_RX_1US_SUPPORT(supp)             (DF_SUPP_TEST(supp, \
+						BT_HCI_LE_1US_AOA_RX))
+
 /* @brief Function provides information about DF antennae numer and
  *	  controller capabilities related with Constant Tone Extension.
  *
@@ -131,3 +156,30 @@ static int hci_df_set_conn_cte_tx_param(struct bt_conn *conn, uint8_t cte_types,
 
 	return err;
 }
+
+/* @brief Function initializes Direction Finding in Host
+ *
+ * @return Zero in case of success, other value in case of failure.
+ */
+int le_df_init(void)
+{
+	uint8_t max_switch_pattern_len;
+	uint8_t switch_sample_rates;
+	uint8_t max_cte_len;
+	uint8_t num_ant;
+	int err;
+
+	err = hci_df_read_ant_info(&switch_sample_rates, &num_ant,
+			     &max_switch_pattern_len, &max_cte_len);
+	if (err) {
+		return err;
+	}
+
+	df_ant_info.max_switch_pattern_len = max_switch_pattern_len;
+	df_ant_info.switch_sample_rates = switch_sample_rates;
+	df_ant_info.max_cte_len = max_cte_len;
+	df_ant_info.num_ant = num_ant;
+
+	BT_DBG("DF initialized.");
+	return 0;
+}

subsys/bluetooth/host/direction_internal.h

@@ -0,0 +1,8 @@
+/*
+ * Copyright (c) 2020 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Performs initialization of Direction Finding in Host */
+int le_df_init(void);

subsys/bluetooth/host/hci_core.c

@@ -47,6 +47,10 @@
 #include "crypto.h"
 #include "settings.h"
 
+#if IS_ENABLED(CONFIG_BT_DF)
+#include "direction_internal.h"
+#endif /* CONFIG_BT_DF */
+
 #if !defined(CONFIG_BT_EXT_ADV_LEGACY_SUPPORT)
 #undef BT_FEAT_LE_EXT_ADV
 #define BT_FEAT_LE_EXT_ADV(feat)  1
@@ -5722,6 +5726,15 @@ static int le_init(void)
 	}
 #endif
 
+#if IS_ENABLED(CONFIG_BT_DF)
+	if (BT_FEAT_LE_CONNECTIONLESS_CTE_TX(bt_dev.le.features)) {
+		err = le_df_init();
+		if (err) {
+			return err;
+		}
+	}
+#endif /* CONFIG_BT_DF */
+
 	return  le_set_event_mask();
 }