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This software, with or without modification, must only be used with a * Nordic Semiconductor ASA integrated circuit. * * 5. Any software provided in binary form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ /**@file * * @defgroup hci_transport HCI Transport * @{ * @ingroup app_common * * @brief HCI transport module implementation. * * This module implements certain specific features from the three-wire UART transport layer, * defined by the Bluetooth specification version 4.0 [Vol 4] part D. * * \par Features supported * - Transmission and reception of Vendor Specific HCI packet type application packets. * - Transmission and reception of reliable packets: defined by chapter 6 of the specification. * * \par Features not supported * - Link establishment procedure: defined by chapter 8 of the specification. * - Low power: defined by chapter 9 of the specification. * * \par Implementation specific behaviour * - As Link establishment procedure is not supported following static link configuration parameters * are used: * + TX window size is 1. * + 16 bit CCITT-CRC must be used. * + Out of frame software flow control not supported. * + Parameters specific for resending reliable packets are compile time configurable (clarifed * later in this document). * + Acknowledgement packet transmissions are not timeout driven , meaning they are delivered for * transmission within same context which the corresponding application packet was received. * * \par Implementation specific limitations * Current implementation has the following limitations which will have impact to system wide * behaviour: * - Delayed acknowledgement scheduling not implemented: * There exists a possibility that acknowledgement TX packet and application TX packet will collide * in the TX pipeline having the end result that acknowledgement packet will be excluded from the TX * pipeline which will trigger the retransmission algorithm within the peer protocol entity. * - Delayed retransmission scheduling not implemented: * There exists a possibility that retransmitted application TX packet and acknowledgement TX packet * will collide in the TX pipeline having the end result that retransmitted application TX packet * will be excluded from the TX pipeline. * - Processing of the acknowledgement number from RX application packets: * Acknowledgement number is not processed from the RX application packets having the end result * that unnecessary application packet retransmissions can occur. * * The application TX packet processing flow is illustrated by the statemachine below. * * @image html hci_transport_tx_sm.svg "TX - application packet statemachine" * * \par Component specific configuration options * * The following compile time configuration options are available, and used to configure the * application TX packet retransmission interval, in order to suite various application specific * implementations: * - MAC_PACKET_SIZE_IN_BITS Maximum size of a single application packet in bits. * - USED_BAUD_RATE Used uart baudrate. * * The following compile time configuration option is available to configure module specific * behaviour: * - MAX_RETRY_COUNT Max retransmission retry count for applicaton packets. */ #ifndef HCI_TRANSPORT_H__ #define HCI_TRANSPORT_H__ #include #include "nrf_error.h" #ifdef __cplusplus extern "C" { #endif /**@brief Generic event callback function events. */ typedef enum { HCI_TRANSPORT_RX_RDY, /**< An event indicating that RX packet is ready for read. */ HCI_TRANSPORT_EVT_TYPE_MAX /**< Enumeration upper bound. */ } hci_transport_evt_type_t; /**@brief Struct containing events from the Transport layer. */ typedef struct { hci_transport_evt_type_t evt_type; /**< Type of event. */ } hci_transport_evt_t; /**@brief Transport layer generic event callback function type. * * @param[in] event Transport layer event. */ typedef void (*hci_transport_event_handler_t)(hci_transport_evt_t event); /**@brief TX done event callback function result codes. */ typedef enum { HCI_TRANSPORT_TX_DONE_SUCCESS, /**< Transmission success, peer transport entity has acknowledged the transmission. */ HCI_TRANSPORT_TX_DONE_FAILURE /**< Transmission failure. */ } hci_transport_tx_done_result_t; /**@brief Transport layer TX done event callback function type. * * @param[in] result TX done event result code. */ typedef void (*hci_transport_tx_done_handler_t)(hci_transport_tx_done_result_t result); /**@brief Function for registering a generic event handler. * * @note Multiple registration requests will overwrite any possible existing registration. * * @param[in] event_handler The function to be called by the transport layer upon an event. * * @retval NRF_SUCCESS Operation success. * @retval NRF_ERROR_NULL Operation failure. NULL pointer supplied. */ uint32_t hci_transport_evt_handler_reg(hci_transport_event_handler_t event_handler); /**@brief Function for registering a handler for TX done event. * * @note Multiple registration requests will overwrite any possible existing registration. * * @param[in] event_handler The function to be called by the transport layer upon TX done * event. * * @retval NRF_SUCCESS Operation success. * @retval NRF_ERROR_NULL Operation failure. NULL pointer supplied. */ uint32_t hci_transport_tx_done_register(hci_transport_tx_done_handler_t event_handler); /**@brief Function for opening the transport channel and initializing the transport layer. * * @warning Must not be called for a channel which has been allready opened. * * @retval NRF_SUCCESS Operation success. * @retval NRF_ERROR_INTERNAL Operation failure. Internal error ocurred. */ uint32_t hci_transport_open(void); /**@brief Function for closing the transport channel. * * @note Can be called multiple times and also for not opened channel. * * @retval NRF_SUCCESS Operation success. */ uint32_t hci_transport_close(void); /**@brief Function for allocating tx packet memory. * * @param[out] pp_memory Pointer to the packet data. * * @retval NRF_SUCCESS Operation success. Memory was allocated. * @retval NRF_ERROR_NO_MEM Operation failure. No memory available. * @retval NRF_ERROR_NULL Operation failure. NULL pointer supplied. */ uint32_t hci_transport_tx_alloc(uint8_t ** pp_memory); /**@brief Function for freeing tx packet memory. * * @note Memory management works in FIFO principle meaning that free order must match the alloc * order. * * @retval NRF_SUCCESS Operation success. Memory was freed. */ uint32_t hci_transport_tx_free(void); /**@brief Function for writing a packet. * * @note Completion of this method does not guarantee that actual peripheral transmission would * have completed. * * @note In case of 0 byte packet length write request, message will consist of only transport * module specific headers. * * @retval NRF_SUCCESS Operation success. Packet was added to the transmission queue * and an event will be send upon transmission completion. * @retval NRF_ERROR_NO_MEM Operation failure. Transmission queue is full and packet was not * added to the transmission queue. User should wait for * a appropriate event prior issuing this operation again. * @retval NRF_ERROR_DATA_SIZE Operation failure. Packet size exceeds limit. * @retval NRF_ERROR_NULL Operation failure. NULL pointer supplied. * @retval NRF_ERROR_INVALID_STATE Operation failure. Channel is not open. */ uint32_t hci_transport_pkt_write(const uint8_t * p_buffer, uint16_t length); /**@brief Function for extracting received packet. * * @note Extracted memory can't be reused by the underlying transport layer untill freed by call to * hci_transport_rx_pkt_consume(). * * @param[out] pp_buffer Pointer to the packet data. * @param[out] p_length Length of packet data in bytes. * * @retval NRF_SUCCESS Operation success. Packet was extracted. * @retval NRF_ERROR_NO_MEM Operation failure. No packet available to extract. * @retval NRF_ERROR_NULL Operation failure. NULL pointer supplied. */ uint32_t hci_transport_rx_pkt_extract(uint8_t ** pp_buffer, uint16_t * p_length); /**@brief Function for consuming extracted packet described by p_buffer. * * RX memory pointed to by p_buffer is freed and can be reused by the underlying transport layer. * * @param[in] p_buffer Pointer to the buffer that has been consumed. * * @retval NRF_SUCCESS Operation success. * @retval NRF_ERROR_NO_MEM Operation failure. No packet available to consume. * @retval NRF_ERROR_INVALID_ADDR Operation failure. Not a valid pointer. */ uint32_t hci_transport_rx_pkt_consume(uint8_t * p_buffer); #ifdef __cplusplus } #endif #endif // HCI_TRANSPORT_H__ /** @} */