hid_host: document API

src/classic/hid_host.h

@@ -120,57 +120,145 @@ typedef struct {
 } hid_host_connection_t;
 
 /* API_START */
+
 /**
  * @brief Set up HID Host 
- * @param boot_protocol_mode_supported
  * @param hid_descriptor_storage
  * @param hid_descriptor_storage_len
  */
 void hid_host_init(uint8_t * hid_descriptor_storage, uint16_t hid_descriptor_storage_len);
 
 /**
- * @brief Register callback for the HID Device Host. 
+ * @brief Register callback for the HID Host. 
  * @param callback
  */
 void hid_host_register_packet_handler(btstack_packet_handler_t callback);
 
 /*
- * @brief Create HID connection to HID Host
+ * @brief Create HID connection to HID Device and emit HID_SUBEVENT_CONNECTION_OPENED event with status code.
+ * @note  HID_PROTOCOL_MODE_REPORT_WITH_FALLBACK_TO_BOOT will try ti set up REPORT mode, but fallback to BOOT mode if necessary. 
+ * @note  Reports from HID Device are received via HID_SUBEVENT_REPORT.
  * @param remote_addr
+ * @param protocol_mode see hid_protocol_mode_t in hid.h
  * @param hid_cid to use for other commands
- * @result status
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_COMMAND_DISALLOWED, BTSTACK_MEMORY_ALLOC_FAILED
  */
 uint8_t hid_host_connect(bd_addr_t remote_addr, hid_protocol_mode_t protocol_mode, uint16_t * hid_cid);
 
+
+/*
+ * @brief Accept incoming HID connection, this should be called upon receiving HID_SUBEVENT_INCOMING_CONNECTION event.
+ * @param hid_cid
+ * @param protocol_mode see hid_protocol_mode_t in hid.h
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_accept_connection(uint16_t hid_cid, hid_protocol_mode_t protocol_mode);
+
+/*
+ * @brief Decline incoming HID connection, this should be called upon receiving HID_SUBEVENT_INCOMING_CONNECTION event.
+ * @param hid_cid
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_decline_connection(uint16_t hid_cid);
 
 /*
- * @brief Disconnect from HID Host
+ * @brief Disconnect from HID Device and emit HID_SUBEVENT_CONNECTION_CLOSED event.
  * @param hid_cid
  */
 void hid_host_disconnect(uint16_t hid_cid);
 
 // Control messages:
+
+/*
+ * @brief Send SUSPEND control signal to connected HID Device. A Bluetooth HID Device which receives a SUSPEND control signal
+ * may optionally disconnect from the Bluetooth HID Host.
+ * @param hid_cid
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_send_suspend(uint16_t hid_cid);
+
+/*
+ * @brief Order connected HID Device to exit suspend mode. 
+ * The Bluetooth HID Device shall send a report to the Bluetooth HID Host.
+ * @param hid_cid
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_send_exit_suspend(uint16_t hid_cid);
+
+/*
+ * @brief Unplug connected HID Device. 
+ * @note This is the only command that can be also received from HID Device. It will be indicated by receiving 
+ * HID_SUBEVENT_VIRTUAL_CABLE_UNPLUG event, as well as disconnecting HID Host from device.
+ * @param hid_cid
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_send_virtual_cable_unplug(uint16_t hid_cid);
 
+/*
+ * @brief Set Protocol Mode on the Bluetooth HID Device and emit HID_SUBEVENT_SET_PROTOCOL_RESPONSE event with handshake_status, see hid_handshake_param_type_t
+ * @param hid_cid
+ * @param protocol_mode see hid_protocol_mode_t in hid.h
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_send_set_protocol_mode(uint16_t hid_cid, hid_protocol_mode_t protocol_mode);
+
+/*
+ * @brief Retrieve the Protocol Mode of the Bluetooth HID Device and emit HID_SUBEVENT_GET_PROTOCOL_RESPONSE with handshake_status, see hid_handshake_param_type_t
+ * @param hid_cid
+ * @param protocol_mode see hid_protocol_mode_t in hid.h
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_send_get_protocol(uint16_t hid_cid);
 
+/*
+
+ * @brief Send report to a Bluetooth HID Device and emit HID_SUBEVENT_SET_REPORT_RESPONSE with handshake_status, see hid_handshake_param_type_t. The Bluetooth HID Host shall send complete reports.
+ * @param hid_cid
+ * @param report_type see hid_report_type_t in hid.h
+ * @param report_id
+ * @param report
+ * @param report_len
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_send_set_report(uint16_t hid_cid, hid_report_type_t report_type, uint8_t report_id, const uint8_t * report, uint8_t report_len);
+
+/*
+ * @brief Request a HID report from the Bluetooth HID Device and emit HID_SUBEVENT_GET_REPORT_RESPONSE event with with handshake_status, see hid_handshake_param_type_t. 
+ * Polling Bluetooth HID Devices using the GET_REPORT transfer is costly in terms of time and overhead, 
+ * and should be avoided whenever possible. The GET_REPORT transfer is typically only used by applications 
+ * to determine the initial state of a Bluetooth HID Device. If the state of a report changes frequently, 
+ * then the report should be reported over the more efficient Interrupt channel, see hid_host_send_report.
+ * @param hid_cid
+ * @param report_type see hid_report_type_t in hid.h
+ * @param report_id
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
+ */
 uint8_t hid_host_send_get_report(uint16_t hid_cid, hid_report_type_t report_type, uint8_t report_id);
 
 /**
- * @brief Send HID message on interrupt channel
+ * @brief Send HID output report on interrupt channel.
  * @param hid_cid
+ * @param report_id
+ * @param report
+ * @param report_len
+ * @result status ERROR_CODE_SUCCESS on success, otherwise ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER, ERROR_CODE_COMMAND_DISALLOWED
  */
-// on interrupt channel, allways output
 uint8_t hid_host_send_report(uint16_t hid_cid, uint8_t report_id, const uint8_t * report, uint8_t report_len);
 
+/*
+ * @brief Get descriptor data
+ * @param hid_cid
+ * @result data
+ */
 const uint8_t * hid_descriptor_storage_get_descriptor_data(uint16_t hid_cid);
+
+/*
+ * @brief Get descriptor length
+ * @param hid_cid
+ * @result length
+ */
 const uint16_t hid_descriptor_storage_get_descriptor_len(uint16_t hid_cid);
+
 /* API_END */