/* * Copyright (c) 2015 - 2020, 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 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 the copyright holder nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER 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 #include #ifdef __cplusplus extern "C" { #endif /** * @defgroup nrfx_twi TWI driver * @{ * @ingroup nrf_twi * @brief Two Wire Interface master (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; ///< Index of the driver instance. For internal use only. } 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), \ } #ifndef __NRFX_DOXYGEN__ 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 }; #endif /** @brief Structure for the configuration of the TWI master driver instance. */ 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. * * This configuration sets up TWI with the following options: * - clock frequency: 100 kHz * - disable bus holding after uninit * * @param[in] _pin_scl SCL pin. * @param[in] _pin_sda SDA pin. */ #define NRFX_TWI_DEFAULT_CONFIG(_pin_scl, _pin_sda) \ { \ .scl = _pin_scl, \ .sda = _pin_sda, \ .frequency = NRF_TWI_FREQ_100K, \ .interrupt_priority = NRFX_TWI_DEFAULT_CONFIG_IRQ_PRIORITY, \ .hold_bus_uninit = false, \ } /** @brief Flag indicating that the interrupt after each transfer will be suppressed, and the event handler will not be called. */ #define NRFX_TWI_FLAG_NO_XFER_EVT_HANDLER (1UL << 2) /** @brief Flag indicating that the TX transfer will not end with a stop condition. */ #define NRFX_TWI_FLAG_TX_NO_STOP (1UL << 5) /** @brief Flag indicating that the transfer will be suspended. */ #define NRFX_TWI_FLAG_SUSPEND (1UL << 6) /** @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_OVERRUN, ///< Error event: The unread data is replaced by new data. NRFX_TWI_EVT_BUS_ERROR ///< Error event: An unexpected transition occurred on the bus. } 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), \ .secondary_length = 0, \ .p_primary_buf = (p_data), \ .p_secondary_buf = NULL, \ } /** @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), \ .secondary_length = 0, \ .p_primary_buf = (p_data), \ .p_secondary_buf = NULL, \ } /** @brief Macro for setting the TX-RX 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 TX-TX 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 the 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 Initialization is successful. * @retval NRFX_ERROR_INVALID_STATE The driver is in invalid state. * @retval NRFX_ERROR_BUSY 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 performing 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 TX-RX and TX-TX 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. * - @ref NRFX_TWI_FLAG_SUSPEND - Transfer will be suspended. This allows for combining multiple transfers into one transaction. * Only transactions with the same direction can be combined. To finish the transaction, call the function without this flag. * * @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 The procedure is successful. * @retval NRFX_ERROR_BUSY The driver is not ready for a new transfer. * @retval NRFX_ERROR_NOT_SUPPORTED The provided parameters are not supported. * @retval NRFX_ERROR_INTERNAL An unexpected transition occurred on the bus. * @retval NRFX_ERROR_INVALID_STATE Other direction of transaction is suspended on the bus. * @retval NRFX_ERROR_DRV_TWI_ERR_OVERRUN The unread data is replaced by new data (TXRX and RX) * @retval NRFX_ERROR_DRV_TWI_ERR_ANACK Negative acknowledgement (NACK) is received after sending * the address in polling mode. * @retval NRFX_ERROR_DRV_TWI_ERR_DNACK Negative acknowledgement (NACK) is received after sending * a data byte in polling mode. */ 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 The TWI driver is currently busy performing a transfer. * @retval false 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 * 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); /** * @brief Function for recovering the bus. * * This function checks if the bus is not stuck because of a slave holding the SDA line in the low state, * and if needed it performs required number of pulses on the SCL line to make the slave release the SDA line. * Finally, the function generates a STOP condition on the bus to put it into a known state. * * @note This function can be used only if the TWI driver is uninitialized. * * @param[in] scl_pin SCL pin number. * @param[in] sda_pin SDA pin number. * * @retval NRFX_SUCCESS Bus recovery was successful. * @retval NRFX_ERROR_INTERNAL Bus recovery failed. */ NRFX_STATIC_INLINE nrfx_err_t nrfx_twi_bus_recover(uint32_t scl_pin, uint32_t sda_pin); #ifndef NRFX_DECLARE_ONLY NRFX_STATIC_INLINE nrfx_err_t nrfx_twi_bus_recover(uint32_t scl_pin, uint32_t sda_pin) { return nrfx_twi_twim_bus_recover(scl_pin, sda_pin); } #endif /** @} */ void nrfx_twi_0_irq_handler(void); void nrfx_twi_1_irq_handler(void); #ifdef __cplusplus } #endif #endif // NRFX_TWI_H__