/** * Copyright (c) 2015 - 2018, 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 NRFX_TWI_H__ #define NRFX_TWI_H__ #include #include #ifdef __cplusplus extern "C" { #endif /** * @defgroup nrfx_twi TWI driver * @{ * @ingroup nrf_twi * @brief TWI peripheral driver. */ /** * @brief Structure for the TWI master driver instance. */ typedef struct { NRF_TWI_Type * p_twi; ///< Pointer to a structure with TWI registers. uint8_t drv_inst_idx; ///< Driver instance index. } nrfx_twi_t; /** * @brief Macro for creating a TWI master driver instance. */ #define NRFX_TWI_INSTANCE(id) \ { \ .p_twi = NRFX_CONCAT_2(NRF_TWI, id), \ .drv_inst_idx = NRFX_CONCAT_3(NRFX_TWI, id, _INST_IDX), \ } enum { #if NRFX_CHECK(NRFX_TWI0_ENABLED) NRFX_TWI0_INST_IDX, #endif #if NRFX_CHECK(NRFX_TWI1_ENABLED) NRFX_TWI1_INST_IDX, #endif NRFX_TWI_ENABLED_COUNT }; /** * @brief Structure for the TWI master driver instance configuration. */ typedef struct { uint32_t scl; ///< SCL pin number. uint32_t sda; ///< SDA pin number. nrf_twi_frequency_t frequency; ///< TWI frequency. uint8_t interrupt_priority; ///< Interrupt priority. bool hold_bus_uninit; ///< Hold pull up state on gpio pins after uninit. } nrfx_twi_config_t; /** * @brief TWI master driver instance default configuration. */ #define NRFX_TWI_DEFAULT_CONFIG \ { \ .frequency = (nrf_twi_frequency_t)NRFX_TWI_DEFAULT_CONFIG_FREQUENCY, \ .scl = 31, \ .sda = 31, \ .interrupt_priority = NRFX_TWI_DEFAULT_CONFIG_IRQ_PRIORITY, \ .hold_bus_uninit = NRFX_TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT, \ } #define NRFX_TWI_FLAG_NO_XFER_EVT_HANDLER (1UL << 2) /**< Interrupt after each transfer is suppressed, and the event handler is not called. */ #define NRFX_TWI_FLAG_TX_NO_STOP (1UL << 5) /**< Flag indicating that the TX transfer will not end with a stop condition. */ /** * @brief TWI master driver event types. */ typedef enum { NRFX_TWI_EVT_DONE, ///< Transfer completed event. NRFX_TWI_EVT_ADDRESS_NACK, ///< Error event: NACK received after sending the address. NRFX_TWI_EVT_DATA_NACK ///< Error event: NACK received after sending a data byte. } nrfx_twi_evt_type_t; /** * @brief TWI master driver transfer types. */ typedef enum { NRFX_TWI_XFER_TX, ///< TX transfer. NRFX_TWI_XFER_RX, ///< RX transfer. NRFX_TWI_XFER_TXRX, ///< TX transfer followed by RX transfer with repeated start. NRFX_TWI_XFER_TXTX ///< TX transfer followed by TX transfer with repeated start. } nrfx_twi_xfer_type_t; /** * @brief Structure for a TWI transfer descriptor. */ typedef struct { nrfx_twi_xfer_type_t type; ///< Type of transfer. uint8_t address; ///< Slave address. size_t primary_length; ///< Number of bytes transferred. size_t secondary_length; ///< Number of bytes transferred. uint8_t * p_primary_buf; ///< Pointer to transferred data. uint8_t * p_secondary_buf; ///< Pointer to transferred data. } nrfx_twi_xfer_desc_t; /**@brief Macro for setting the TX transfer descriptor. */ #define NRFX_TWI_XFER_DESC_TX(addr, p_data, length) \ { \ .type = NRFX_TWI_XFER_TX, \ .address = addr, \ .primary_length = length, \ .p_primary_buf = p_data, \ } /**@brief Macro for setting the RX transfer descriptor. */ #define NRFX_TWI_XFER_DESC_RX(addr, p_data, length) \ { \ .type = NRFX_TWI_XFER_RX, \ .address = addr, \ .primary_length = length, \ .p_primary_buf = p_data, \ } /**@brief Macro for setting the TXRX transfer descriptor. */ #define NRFX_TWI_XFER_DESC_TXRX(addr, p_tx, tx_len, p_rx, rx_len) \ { \ .type = NRFX_TWI_XFER_TXRX, \ .address = addr, \ .primary_length = tx_len, \ .secondary_length = rx_len, \ .p_primary_buf = p_tx, \ .p_secondary_buf = p_rx, \ } /**@brief Macro for setting the TXTX transfer descriptor. */ #define NRFX_TWI_XFER_DESC_TXTX(addr, p_tx, tx_len, p_tx2, tx_len2) \ { \ .type = NRFX_TWI_XFER_TXTX, \ .address = addr, \ .primary_length = tx_len, \ .secondary_length = tx_len2, \ .p_primary_buf = p_tx, \ .p_secondary_buf = p_tx2, \ } /** * @brief Structure for a TWI event. */ typedef struct { nrfx_twi_evt_type_t type; ///< Event type. nrfx_twi_xfer_desc_t xfer_desc; ///< Transfer details. } nrfx_twi_evt_t; /** * @brief TWI event handler prototype. */ typedef void (* nrfx_twi_evt_handler_t)(nrfx_twi_evt_t const * p_event, void * p_context); /** * @brief Function for initializing the TWI driver instance. * * @param[in] p_instance Pointer to the driver instance structure. * @param[in] p_config Pointer to the structure with initial configuration. * @param[in] event_handler Event handler provided by the user. If NULL, blocking mode is enabled. * @param[in] p_context Context passed to event handler. * * @retval NRFX_SUCCESS If initialization was successful. * @retval NRFX_ERROR_INVALID_STATE If the driver is in invalid state. * @retval NRFX_ERROR_BUSY If some other peripheral with the same * instance ID is already in use. This is * possible only if @ref nrfx_prs module * is enabled. */ nrfx_err_t nrfx_twi_init(nrfx_twi_t const * p_instance, nrfx_twi_config_t const * p_config, nrfx_twi_evt_handler_t event_handler, void * p_context); /** * @brief Function for uninitializing the TWI instance. * * @param[in] p_instance Pointer to the driver instance structure. */ void nrfx_twi_uninit(nrfx_twi_t const * p_instance); /** * @brief Function for enabling the TWI instance. * * @param[in] p_instance Pointer to the driver instance structure. */ void nrfx_twi_enable(nrfx_twi_t const * p_instance); /** * @brief Function for disabling the TWI instance. * * @param[in] p_instance Pointer to the driver instance structure. */ void nrfx_twi_disable(nrfx_twi_t const * p_instance); /** * @brief Function for sending data to a TWI slave. * * The transmission will be stopped when an error occurs. If a transfer is ongoing, * the function returns the error code @ref NRFX_ERROR_BUSY. * * @param[in] p_instance Pointer to the driver instance structure. * @param[in] address Address of a specific slave device (only 7 LSB). * @param[in] p_data Pointer to a transmit buffer. * @param[in] length Number of bytes to send. * @param[in] no_stop If set, the stop condition is not generated on the bus * after the transfer has completed successfully (allowing * for a repeated start in the next transfer). * * @retval NRFX_SUCCESS If the procedure was successful. * @retval NRFX_ERROR_BUSY If the driver is not ready for a new transfer. * @retval NRFX_ERROR_INTERNAL If an error was detected by hardware. * @retval NRFX_ERROR_DRV_TWI_ERR_ANACK If NACK received after sending the address in polling mode. * @retval NRFX_ERROR_DRV_TWI_ERR_DNACK If NACK received after sending a data byte in polling mode. */ nrfx_err_t nrfx_twi_tx(nrfx_twi_t const * p_instance, uint8_t address, uint8_t const * p_data, size_t length, bool no_stop); /** * @brief Function for reading data from a TWI slave. * * The transmission will be stopped when an error occurs. If a transfer is ongoing, * the function returns the error code @ref NRFX_ERROR_BUSY. * * @param[in] p_instance Pointer to the driver instance structure. * @param[in] address Address of a specific slave device (only 7 LSB). * @param[in] p_data Pointer to a receive buffer. * @param[in] length Number of bytes to be received. * * @retval NRFX_SUCCESS If the procedure was successful. * @retval NRFX_ERROR_BUSY If the driver is not ready for a new transfer. * @retval NRFX_ERROR_INTERNAL If an error was detected by hardware. * @retval NRFX_ERROR_DRV_TWI_ERR_OVERRUN If the unread data was replaced by new data * @retval NRFX_ERROR_DRV_TWI_ERR_ANACK If NACK received after sending the address in polling mode. * @retval NRFX_ERROR_DRV_TWI_ERR_DNACK If NACK received after sending a data byte in polling mode. */ nrfx_err_t nrfx_twi_rx(nrfx_twi_t const * p_instance, uint8_t address, uint8_t * p_data, size_t length); /** * @brief Function for preparing a TWI transfer. * * The following transfer types can be configured (@ref nrfx_twi_xfer_desc_t::type): * - @ref NRFX_TWI_XFER_TXRX: Write operation followed by a read operation (without STOP condition in between). * - @ref NRFX_TWI_XFER_TXTX: Write operation followed by a write operation (without STOP condition in between). * - @ref NRFX_TWI_XFER_TX: Write operation (with or without STOP condition). * - @ref NRFX_TWI_XFER_RX: Read operation (with STOP condition). * * @note TXRX and TXTX transfers are supported only in non-blocking mode. * * Additional options are provided using the flags parameter: * - @ref NRFX_TWI_FLAG_NO_XFER_EVT_HANDLER: No user event handler after transfer completion. In most cases, this also means no interrupt at the end of the transfer. * - @ref NRFX_TWI_FLAG_TX_NO_STOP: No stop condition after TX transfer. * * @note * Some flag combinations are invalid: * - @ref NRFX_TWI_FLAG_TX_NO_STOP with @ref nrfx_twi_xfer_desc_t::type different than @ref NRFX_TWI_XFER_TX * * @param[in] p_instance Pointer to the driver instance structure. * @param[in] p_xfer_desc Pointer to the transfer descriptor. * @param[in] flags Transfer options (0 for default settings). * * @retval NRFX_SUCCESS If the procedure was successful. * @retval NRFX_ERROR_BUSY If the driver is not ready for a new transfer. * @retval NRFX_ERROR_NOT_SUPPORTED If the provided parameters are not supported. * @retval NRFX_ERROR_INTERNAL If an error was detected by hardware. * @retval NRFX_ERROR_DRV_TWI_ERR_OVERRUN If the unread data was replaced by new data (TXRX and RX) * @retval NRFX_ERROR_DRV_TWI_ERR_ANACK If NACK received after sending the address. * @retval NRFX_ERROR_DRV_TWI_ERR_DNACK If NACK received after sending a data byte. */ nrfx_err_t nrfx_twi_xfer(nrfx_twi_t const * p_instance, nrfx_twi_xfer_desc_t const * p_xfer_desc, uint32_t flags); /** * @brief Function for checking the TWI driver state. * * @param[in] p_instance TWI instance. * * @retval true If the TWI driver is currently busy performing a transfer. * @retval false If the TWI driver is ready for a new transfer. */ bool nrfx_twi_is_busy(nrfx_twi_t const * p_instance); /** * @brief Function for getting the transferred data count. * * @param[in] p_instance Pointer to the driver instance structure. * * @return Data count. */ size_t nrfx_twi_data_count_get(nrfx_twi_t const * const p_instance); /** * @brief Function for returning the address of a STOPPED TWI event. * * A STOPPED event can be used to detect the end of a transfer if the @ref NRFX_TWI_FLAG_NO_XFER_EVT_HANDLER * option is used. * * @param[in] p_instance Pointer to the driver instance structure. * * @return STOPPED event address. */ uint32_t nrfx_twi_stopped_event_get(nrfx_twi_t const * p_instance); void nrfx_twi_0_irq_handler(void); void nrfx_twi_1_irq_handler(void); /** @} */ #ifdef __cplusplus } #endif #endif // NRFX_TWI_H__