/** * Copyright (c) 2015 - 2017, Nordic Semiconductor ASA * * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form, except as embedded into a Nordic * Semiconductor ASA integrated circuit in a product or a software update for * such product, must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * * 3. Neither the name of Nordic Semiconductor ASA nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * 4. 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. * */ #ifndef APP_TWI_H__ #define APP_TWI_H__ #include #include "nrf_drv_twi.h" #include "sdk_errors.h" #include "nrf_queue.h" #ifdef __cplusplus extern "C" { #endif /** * @defgroup app_twi TWI transaction manager * @{ * @ingroup app_common * * @brief Module for scheduling TWI transactions. */ /** * @brief Flag indicating that a given transfer should not be ended * with a stop condition. * * Use this flag when a stop condition is undesirable between two transfers, * for example, when the first transfer is a write that sets an address in the slave * device and the second one is a read that fetches certain data using this * address. In this case, the second transfer should follow directly after the * first transfer, with a repeated start condition instead of a stop and then * a new start condition. */ #define APP_TWI_NO_STOP 0x01 /** * @brief Macro for creating a write transfer. * * @param[in] address Slave address. * @param[in] p_data Pointer to the data to be sent. * @param[in] length Number of bytes to transfer. * @param[in] flags Transfer flags (see @ref APP_TWI_NO_STOP). */ #define APP_TWI_WRITE(address, p_data, length, flags) \ APP_TWI_TRANSFER(APP_TWI_WRITE_OP(address), p_data, length, flags) /** * @brief Macro for creating a read transfer. * * @param address Slave address. * @param[in] p_data Pointer to the buffer where received data should be placed. * @param length Number of bytes to transfer. * @param flags Transfer flags (see @ref APP_TWI_NO_STOP). */ #define APP_TWI_READ(address, p_data, length, flags) \ APP_TWI_TRANSFER(APP_TWI_READ_OP(address), p_data, length, flags) /** * @brief Helper macro, should not be used directly. */ #define APP_TWI_TRANSFER(_operation, _p_data, _length, _flags) \ { \ .p_data = (uint8_t *)(_p_data), \ .length = _length, \ .operation = _operation, \ .flags = _flags \ } /** * @brief Helper macro, should not be used directly. */ #define APP_TWI_WRITE_OP(address) (((address) << 1) | 0) /** * @brief Helper macro, should not be used directly. */ #define APP_TWI_READ_OP(address) (((address) << 1) | 1) /** * @brief Helper macro, should not be used directly. */ #define APP_TWI_IS_READ_OP(operation) ((operation) & 1) /** * @brief Helper macro, should not be used directly. */ #define APP_TWI_OP_ADDRESS(operation) ((operation) >> 1) /** * @brief TWI transaction callback prototype. * * @param result Result of operation (NRF_SUCCESS on success, * otherwise a relevant error code). * @param[in] p_user_data Pointer to user data defined in transaction * descriptor. */ typedef void (* app_twi_callback_t)(ret_code_t result, void * p_user_data); /** * @brief TWI transfer descriptor. */ typedef struct { uint8_t * p_data; ///< Pointer to the buffer holding the data. uint8_t length; ///< Number of bytes to transfer. uint8_t operation; ///< Device address combined with transfer direction. uint8_t flags; ///< Transfer flags (see @ref APP_TWI_NO_STOP). } app_twi_transfer_t; /** * @brief TWI transaction descriptor. */ typedef struct { app_twi_callback_t callback; ///< User-specified function to be called after the transaction is finished. void * p_user_data; ///< Pointer to user data to be passed to the callback. app_twi_transfer_t const * p_transfers; ///< Pointer to the array of transfers that make up the transaction. uint8_t number_of_transfers; ///< Number of transfers that make up the transaction. nrf_drv_twi_config_t const * p_required_twi_cfg; ///< Pointer to instance hardware configuration. } app_twi_transaction_t; /** * @brief TWI instance control block. */ typedef struct { app_twi_transaction_t const * volatile p_current_transaction; ///< Currently realized transaction. nrf_drv_twi_config_t default_configuration; ///< Default hardware configuration. nrf_drv_twi_config_t const * p_current_configuration; ///< Pointer to current hardware configuration. uint8_t volatile current_transfer_idx; ///< Index of currently performed transfer (within current transaction). bool volatile internal_transaction_in_progress; ///< Informs that an internal transaction is being performed (by app_twi_perform()). uint8_t volatile internal_transaction_result; ///< Used to pass the result of the internal transaction realized by app_twi_perform(). }app_twi_cb_t; /** * @brief TWI transaction manager instance. */ typedef struct { app_twi_cb_t * p_app_twi_cb; ///< Control block of instance. nrf_queue_t const * p_queue; ///< Transaction queue. nrf_drv_twi_t twi; ///< Pointer to TWI master driver instance. } app_twi_t; /** * @brief Macro that simplifies defining a TWI transaction manager * instance. * * This macro allocates a static buffer for the transaction queue. * Therefore, it should be used in only one place in the code for a given * instance. * * @note The queue size is the maximum number of pending transactions * not counting the one that is currently realized. This means that * for an empty queue with size of, for example, 4 elements, it is * possible to schedule up to 5 transactions. * * @param[in] _app_twi_name Name of instance to be created. * @param[in] _queue_size Size of the transaction queue (maximum number * of pending transactions). * @param[in] _twi_idx Index of hardware TWI instance to be used. */ #define APP_TWI_DEF(_app_twi_name, _queue_size, _twi_idx) \ NRF_QUEUE_DEF(app_twi_transaction_t const *, \ _app_twi_name##_queue, \ (_queue_size), \ NRF_QUEUE_MODE_NO_OVERFLOW); \ static app_twi_cb_t CONCAT_2(_app_twi_name, _cb); \ static const app_twi_t _app_twi_name = \ { \ .p_app_twi_cb = &CONCAT_2(_app_twi_name, _cb), \ .p_queue = &_app_twi_name##_queue, \ .twi = NRF_DRV_TWI_INSTANCE(_twi_idx) \ } /** * @brief Function for initializing a TWI transaction manager instance. * * @param[in] p_app_twi Pointer to the instance to be initialized. * @param[in] p_default_twi_config Pointer to the TWI master driver configuration. This configuration * will be used whenever the scheduled transaction will have * p_twi_configuration set to NULL value. * * @return Values returned by the @ref nrf_drv_twi_init function. */ ret_code_t app_twi_init(app_twi_t const * p_app_twi, nrf_drv_twi_config_t const * p_default_twi_config); /** * @brief Function for uninitializing a TWI transaction manager instance. * * @param[in] p_app_twi Pointer to the instance to be uninitialized. */ void app_twi_uninit(app_twi_t const * p_app_twi); /** * @brief Function for scheduling a TWI transaction. * * The transaction is enqueued and started as soon as the TWI bus is * available, thus when all previously scheduled transactions have been * finished (possibly immediately). * * @note If @ref app_twi_transaction_t::p_required_twi_cfg * is set to a non-NULL value the module will compare it with * @ref app_twi_cb_t::p_current_configuration and reinitialize hardware * TWI instance with new parameters if any differences are found. * If @ref app_twi_transaction_t::p_required_twi_cfg is set to NULL then * it will treat it as it would be set to @ref app_twi_cb_t::default_configuration. * * @param[in] p_app_twi Pointer to the TWI transaction manager instance. * @param[in] p_transaction Pointer to the descriptor of the transaction to be * scheduled. * * @retval NRF_SUCCESS If the transaction has been successfully scheduled. * @retval NRF_ERROR_NO_MEM If the queue is full (Only if queue in * @ref NRF_QUEUE_MODE_NO_OVERFLOW). */ ret_code_t app_twi_schedule(app_twi_t const * p_app_twi, app_twi_transaction_t const * p_transaction); /** * @brief Function for scheduling a transaction and waiting until it is finished. * * This function schedules a transaction that consists of one or more transfers * and waits until it is finished. * * @param[in] p_app_twi Pointer to the TWI transaction manager instance. * @param[in] p_transfers Pointer to an array of transfers to be performed. * @param number_of_transfers Number of transfers to be performed. * @param user_function User-specified function to be called while * waiting. NULL if such functionality * is not needed. * * @retval NRF_SUCCESS If the transfers have been successfully realized. * @retval NRF_ERROR_BUSY If some transfers are already being performed. * @retval - Other error codes mean that the transaction has ended * with the error that is specified in the error code. */ ret_code_t app_twi_perform(app_twi_t const * p_app_twi, app_twi_transfer_t const * p_transfers, uint8_t number_of_transfers, void (* user_function)(void)); /** * @brief Function for getting the current state of a TWI transaction manager * instance. * * @param[in] p_app_twi Pointer to the TWI transaction manager instance. * * @retval true If all scheduled transactions have been finished. * @retval false Otherwise. */ __STATIC_INLINE bool app_twi_is_idle(app_twi_t const * p_app_twi) { return (p_app_twi->p_app_twi_cb->p_current_transaction == NULL); } /** *@} **/ #ifdef __cplusplus } #endif #endif // APP_TWI_H__