[PATCH v1] Bluetooth: hci_sync: Initial LE Channel Sounding support by defining required HCI command/event structures.

Naga Bhavani Akella
2025-12-16T11:38:19Z

1. Implementing the LE Event Mask to include events required for
LE Channel Sounding.
2. Enabling the Channel Sounding feature bit in the
LE Host Supported Features command.
3. Defining HCI command and event structures necessary for
LE Channel Sounding functionality.

Signed-off-by: Naga Bhavani Akella <naga.akella@oss.qualcomm.com>
---
include/net/bluetooth/hci.h | 323 +++++++++++++++++++++++++++++++
include/net/bluetooth/hci_core.h | 6 +
net/bluetooth/hci_sync.c | 15 ++
3 files changed, 344 insertions(+)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index a27cd3626b87..33ec8ddd2119 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -654,6 +654,8 @@ enum {
#define HCI_LE_ISO_BROADCASTER 0x40
#define HCI_LE_ISO_SYNC_RECEIVER 0x80
#define HCI_LE_LL_EXT_FEATURE 0x80
+#define HCI_LE_CHANNEL_SOUNDING 0x40
+#define HCI_LE_CHANNEL_SOUNDING_HOST 0x80

/* Connection modes */
#define HCI_CM_ACTIVE 0x0000
@@ -2269,6 +2271,204 @@ struct hci_cp_le_read_all_remote_features {
__u8 pages;
} __packed;

+/* Channel Sounding Commands */
+#define HCI_OP_LE_CS_RD_LOCAL_SUPP_CAP 0x2089
+struct hci_rp_le_cs_rd_local_supp_cap {
+ __u8 status;
+ __u8 num_config_supported;
+ __le16 max_consecutive_procedures_supported;
+ __u8 num_antennas_supported;
+ __u8 max_antenna_paths_supported;
+ __u8 roles_supported;
+ __u8 modes_supported;
+ __u8 rtt_capability;
+ __u8 rtt_aa_only_n;
+ __u8 rtt_sounding_n;
+ __u8 rtt_random_payload_n;
+ __le16 nadm_sounding_capability;
+ __le16 nadm_random_capability;
+ __u8 cs_sync_phys_supported;
+ __le16 subfeatures_supported;
+ __le16 t_ip1_times_supported;
+ __le16 t_ip2_times_supported;
+ __le16 t_fcs_times_supported;
+ __le16 t_pm_times_supported;
+ __u8 t_sw_time_supported;
+ __u8 tx_snr_capability;
+} __packed;
+
+#define HCI_OP_LE_CS_RD_RMT_SUPP_CAP 0x208A
+struct hci_cp_le_cs_rd_local_supp_cap {
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_OP_LE_CS_WR_CACHED_RMT_SUPP_CAP 0x208B
+struct hci_cp_le_cs_wr_cached_rmt_supp_cap {
+ __le16 conn_hdl;
+ __u8 num_config_supported;
+ __le16 max_consecutive_procedures_supported;
+ __u8 num_antennas_supported;
+ __u8 max_antenna_paths_supported;
+ __u8 roles_supported;
+ __u8 modes_supported;
+ __u8 rtt_capability;
+ __u8 rtt_aa_only_n;
+ __u8 rtt_sounding_n;
+ __u8 rtt_random_payload_n;
+ __le16 nadm_sounding_capability;
+ __le16 nadm_random_capability;
+ __u8 cs_sync_phys_supported;
+ __le16 subfeatures_supported;
+ __le16 t_ip1_times_supported;
+ __le16 t_ip2_times_supported;
+ __le16 t_fcs_times_supported;
+ __le16 t_pm_times_supported;
+ __u8 t_sw_time_supported;
+ __u8 tx_snr_capability;
+} __packed;
+
+struct hci_rp_le_cs_wr_cached_rmt_supp_cap {
+ __u8 status;
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_OP_LE_CS_SEC_ENABLE 0x208C
+struct hci_cp_le_cs_sec_enable {
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_OP_LE_CS_SET_DEFAULT_SETTINGS 0x208D
+struct hci_cp_le_cs_set_default_settings {
+ __le16 conn_hdl;
+ __u8 role_enable;
+ __u8 cs_sync_ant_sel;
+ __s8 max_tx_power;
+} __packed;
+
+struct hci_rp_le_cs_set_default_settings {
+ __u8 status;
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_OP_LE_CS_RD_RMT_FAE_TABLE 0x208E
+struct hci_cp_le_cs_rd_rmt_fae_table {
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_OP_LE_CS_WR_CACHED_RMT_FAE_TABLE 0x208F
+struct hci_cp_le_cs_wr_rmt_cached_fae_table {
+ __le16 conn_hdl;
+ __u8 remote_fae_table[72];
+} __packed;
+
+struct hci_rp_le_cs_wr_rmt_cached_fae_table {
+ __u8 status;
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_OP_LE_CS_CREATE_CONFIG 0x2090
+struct hci_cp_le_cs_create_config {
+ __le16 conn_hdl;
+ __u8 config_id;
+ __u8 create_context;
+ __u8 main_mode_type;
+ __u8 sub_mode_type;
+ __u8 min_main_mode_steps;
+ __u8 max_main_mode_steps;
+ __u8 main_mode_repetition;
+ __u8 mode_0_steps;
+ __u8 role;
+ __u8 rtt_type;
+ __u8 cs_sync_phy;
+ __u8 channel_map[10];
+ __u8 channel_map_repetition;
+ __u8 channel_selection_type;
+ __u8 ch3c_shape;
+ __u8 ch3c_jump;
+ __u8 reserved;
+} __packed;
+
+#define HCI_OP_LE_CS_REMOVE_CONFIG 0x2091
+struct hci_cp_le_cs_remove_config {
+ __le16 conn_hdl;
+ __u8 config_id;
+} __packed;
+
+#define HCI_OP_LE_CS_SET_CH_CLASSIFICATION 0x2092
+struct hci_cp_le_cs_set_ch_classification {
+ __u8 ch_classification[10];
+} __packed;
+
+struct hci_rp_le_cs_set_ch_classification {
+ __u8 status;
+} __packed;
+
+#define HCI_OP_LE_CS_SET_PROC_PARAM 0x2093
+struct hci_cp_le_cs_set_proc_param {
+ __le16 conn_hdl;
+ __u8 config_id;
+ __le16 max_procedure_len;
+ __le16 min_procedure_interval;
+ __le16 max_procedure_interval;
+ __le16 max_procedure_count;
+ __u8 min_subevent_len[3];
+ __u8 max_subevent_len[3];
+ __u8 tone_antenna_config_selection;
+ __u8 phy;
+ __u8 tx_power_delta;
+ __u8 preferred_peer_antenna;
+ __u8 snr_control_initiator;
+ __u8 snr_control_reflector;
+} __packed;
+
+struct hci_rp_le_cs_set_proc_param {
+ __u8 status;
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_OP_LE_CS_SET_PROC_ENABLE 0x2094
+struct hci_cp_le_cs_set_proc_param {
+ __le16 conn_hdl;
+ __u8 config_id;
+ __u8 enable;
+} __packed;
+
+#define HCI_OP_LE_CS_TEST 0x2095
+struct hci_cp_le_cs_test {
+ __u8 main_mode_type;
+ __u8 sub_mode_type;
+ __u8 main_mode_repetition;
+ __u8 mode_0_steps;
+ __u8 role;
+ __u8 rtt_type;
+ __u8 cs_sync_phy;
+ __u8 cs_sync_antenna_selection;
+ __u8 subevent_len[3];
+ __le16 subevent_interval;
+ __u8 max_num_subevents;
+ __u8 transmit_power_level;
+ __u8 t_ip1_time;
+ __u8 t_ip2_time;
+ __u8 t_fcs_time;
+ __u8 t_pm_time;
+ __u8 t_sw_time;
+ __u8 tone_antenna_config_selection;
+ __u8 reserved;
+ __u8 snr_control_initiator;
+ __u8 snr_control_reflector;
+ __le16 drbg_nonce;
+ __u8 channel_map_repetition;
+ __le16 override_config;
+ __u8 override_parameters_length;
+ __u8 override_parameters_data[];
+} __packed;
+
+struct hci_rp_le_cs_test {
+ __u8 status;
+} __packed;
+
+#define HCI_OP_LE_CS_TEST_END 0x2096
+
/* ---- HCI Events ---- */
struct hci_ev_status {
__u8 status;
@@ -2960,6 +3160,129 @@ struct hci_evt_le_read_all_remote_features_complete {
__u8 features[248];
} __packed;

+/* Channel Sounding Events */
+#define HCI_EVT_LE_CS_READ_RMT_SUPP_CAP_COMPLETE 0x2C
+struct hci_evt_le_cs_read_rmt_supp_cap_complete {
+ __u8 status;
+ __le16 conn_hdl;
+ __u8 num_configs_supp;
+ __le16 max_consec_proc_supp;
+ __u8 num_ant_supp;
+ __u8 max_ant_path_supp;
+ __u8 roles_supp;
+ __u8 modes_supp;
+ __u8 rtt_cap;
+ __u8 rtt_aa_only_n;
+ __u8 rtt_sounding_n;
+ __u8 rtt_rand_payload_n;
+ __le16 nadm_sounding_cap;
+ __le16 nadm_rand_cap;
+ __u8 cs_sync_phys_supp;
+ __le16 sub_feat_supp;
+ __le16 t_ip1_times_supp;
+ __le16 t_ip2_times_supp;
+ __le16 t_fcs_times_supp;
+ __le16 t_pm_times_supp;
+ __u8 t_sw_times_supp;
+ __u8 tx_snr_cap;
+} __packed;
+
+#define HCI_EVT_LE_CS_READ_RMT_FAE_TABLE_COMPLETE 0x2D
+struct hci_evt_le_cs_read_rmt_fae_table_complete {
+ __u8 status;
+ __le16 conn_hdl;
+ __u8 remote_fae_table[72];
+} __packed;
+
+#define HCI_EVT_LE_CS_SECURITY_ENABLE_COMPLETE 0x2E
+struct hci_evt_le_cs_security_enable_complete {
+ __u8 status;
+ __le16 conn_hdl;
+} __packed;
+
+#define HCI_EVT_LE_CS_CONFIG_COMPLETE 0x2F
+struct hci_evt_le_cs_config_complete {
+ __u8 status;
+ __le16 conn_hdl;
+ __u8 config_id;
+ __u8 action;
+ __u8 main_mode_type;
+ __u8 sub_mode_type;
+ __u8 min_main_mode_steps;
+ __u8 max_main_mode_steps;
+ __u8 main_mode_rep;
+ __u8 mode_0_steps;
+ __u8 role;
+ __u8 rtt_type;
+ __u8 cs_sync_phy;
+ __u8 channel_map[10];
+ __u8 channel_map_rep;
+ __u8 channel_sel_type;
+ __u8 ch3c_shape;
+ __u8 ch3c_jump;
+ __u8 reserved;
+ __u8 t_ip1_time;
+ __u8 t_ip2_time;
+ __u8 t_fcs_time;
+ __u8 t_pm_time;
+} __packed;
+
+#define HCI_EVT_LE_CS_PROCEDURE_ENABLE_COMPLETE 0x30
+struct hci_evt_le_cs_procedure_enable_complete {
+ __u8 status;
+ __le16 conn_hdl;
+ __u8 config_id;
+ __u8 state;
+ __u8 tone_ant_config_sel;
+ __s8 sel_tx_pwr;
+ __u8 sub_evt_len[3];
+ __u8 sub_evts_per_evt;
+ __le16 sub_evt_intrvl;
+ __le16 evt_intrvl;
+ __le16 proc_intrvl;
+ __le16 proc_counter;
+ __le16 max_proc_len;
+} __packed;
+
+#define HCI_EVT_LE_CS_SUBEVENT_RESULT 0x31
+struct hci_evt_le_cs_subevent_result {
+ __le16 conn_hdl;
+ __u8 config_id;
+ __le16 start_acl_conn_evt_counter;
+ __le16 proc_counter;
+ __le16 freq_comp;
+ __u8 ref_pwr_lvl;
+ __u8 proc_done_status;
+ __u8 subevt_done_status;
+ __u8 abort_reason;
+ __u8 num_ant_paths;
+ __u8 num_steps_reported;
+ __u8 step_mode[0]; /* depends on num_steps_reported */
+ __u8 step_channel[0]; /* depends on num_steps_reported */
+ __u8 step_data_length[0]; /* depends on num_steps_reported */
+ __u8 step_data[0]; /* depends on num_steps_reported */
+} __packed;
+
+#define HCI_EVT_LE_CS_SUBEVENT_RESULT_CONTINUE 0x32
+struct hci_evt_le_cs_subevent_result_continue {
+ __le16 conn_hdl;
+ __u8 config_id;
+ __u8 proc_done_status;
+ __u8 subevt_done_status;
+ __u8 abort_reason;
+ __u8 num_ant_paths;
+ __u8 num_steps_reported;
+ __u8 step_mode[0]; /* depends on num_steps_reported */
+ __u8 step_channel[0]; /* depends on num_steps_reported */
+ __u8 step_data_length[0]; /* depends on num_steps_reported */
+ __u8 step_data[0]; /* depends on num_steps_reported */
+} __packed;
+
+#define HCI_EVT_LE_CS_TEST_END_COMPLETE 0x33
+struct hci_evt_le_cs_test_end_complete {
+ __u8 status;
+} __packed;
+
#define HCI_EV_VENDOR 0xff

/* Internal events generated by Bluetooth stack */
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 4263e71a23ef..0152299a00b9 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -2071,6 +2071,12 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
#define ll_ext_feature_capable(dev) \
((dev)->le_features[7] & HCI_LE_LL_EXT_FEATURE)

+/* Channel sounding support */
+#define chann_sounding_capable(dev) \
+ (((dev)->le_features[5] & HCI_LE_CHANNEL_SOUNDING))
+#define chann_sounding_host_capable(dev) \
+ (((dev)->le_features[5] & HCI_LE_CHANNEL_SOUNDING_HOST))
+
#define mws_transport_config_capable(dev) (((dev)->commands[30] & 0x08) && \
(!hci_test_quirk((dev), HCI_QUIRK_BROKEN_MWS_TRANSPORT_CONFIG)))

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index a9f5b1a68356..67b2c55ec043 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4427,6 +4427,17 @@ static int hci_le_set_event_mask_sync(struct hci_dev *hdev)
events[4] |= 0x02; /* LE BIG Info Advertising Report */
}

+ if (chann_sounding_capable(hdev)) {
+ /* Channel Sounding events */
+ events[5] |= 0x08; /* LE CS Read Remote Supported Cap Complete event */
+ events[5] |= 0x10; /* LE CS Read Remote FAE Table Complete event */
+ events[5] |= 0x20; /* LE CS Security Enable Complete event */
+ events[5] |= 0x40; /* LE CS Config Complete event */
+ events[5] |= 0x80; /* LE CS Procedure Enable Complete event */
+ events[6] |= 0x01; /* LE CS Subevent Result event */
+ events[6] |= 0x02; /* LE CS Subevent Result Continue event */
+ events[6] |= 0x04; /* LE CS Test End Complete event */
+ }
return __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_EVENT_MASK,
sizeof(events), events, HCI_CMD_TIMEOUT);
}
@@ -4572,6 +4583,10 @@ static int hci_le_set_host_feature_sync(struct hci_dev *hdev)
cp.bit_number = 32;
cp.bit_value = iso_enabled(hdev) ? 0x01 : 0x00;

+ /* Channel Sounding (Host Support) */
+ cp.bit_number = 47;
+ cp.bit_value = chann_sounding_capable(hdev) ? 0x01 : 0x00;
+
return __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_HOST_FEATURE,
sizeof(cp), &cp, HCI_CMD_TIMEOUT);
}
--
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