/**
* 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.
*
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*/
/**@file
* @addtogroup nrf_twi Two Wire master interface (TWI/TWIM)
* @ingroup nrf_drivers
* @brief Two Wire master interface (TWI/TWIM) APIs.
*
*
* @defgroup nrf_drv_twi TWIS driver
* @{
* @ingroup nrf_twi
* @brief TWI master APIs.
*/
#ifndef NRF_DRV_TWI_H__
#define NRF_DRV_TWI_H__
#include "nordic_common.h"
#include "sdk_config.h"
// This set of macros makes it possible to exclude parts of code when one type
// of supported peripherals is not used.
#if ((TWI0_ENABLED == 1 && TWI0_USE_EASY_DMA == 1) || \
(TWI1_ENABLED == 1 && TWI1_USE_EASY_DMA == 1))
#define TWIM_IN_USE
#endif
#if ((TWI0_ENABLED == 1 && TWI0_USE_EASY_DMA != 1) || \
(TWI1_ENABLED == 1 && TWI1_USE_EASY_DMA != 1))
#define TWI_IN_USE
#endif
#include "nrf_twi.h"
#ifdef TWIM_IN_USE
#include "nrf_twim.h"
#endif
#include "sdk_errors.h"
#ifdef __cplusplus
extern "C" {
#endif
#if defined(TWIM_IN_USE)
#define NRF_DRV_TWI_PERIPHERAL(id) \
(CONCAT_3(TWI, id, _USE_EASY_DMA) == 1 ? \
(void *)CONCAT_2(NRF_TWIM, id) \
: (void *)CONCAT_2(NRF_TWI, id))
#else
#define NRF_DRV_TWI_PERIPHERAL(id) (void *)CONCAT_2(NRF_TWI, id)
#endif
/**
* @brief Structure for the TWI master driver instance.
*/
typedef struct
{
union
{
#ifdef TWIM_IN_USE
NRF_TWIM_Type * p_twim; ///< Pointer to a structure with TWIM registers.
#endif
NRF_TWI_Type * p_twi; ///< Pointer to a structure with TWI registers.
} reg;
uint8_t drv_inst_idx; ///< Driver instance index.
bool use_easy_dma; ///< True if the peripheral with EasyDMA (TWIM) shall be used.
} nrf_drv_twi_t;
#define TWI0_INSTANCE_INDEX 0
#define TWI1_INSTANCE_INDEX TWI0_INSTANCE_INDEX+TWI0_ENABLED
/**
* @brief Macro for creating a TWI master driver instance.
*/
#define NRF_DRV_TWI_INSTANCE(id) \
{ \
.reg = {NRF_DRV_TWI_PERIPHERAL(id)}, \
.drv_inst_idx = CONCAT_3(TWI, id, _INSTANCE_INDEX), \
.use_easy_dma = CONCAT_3(TWI, id, _USE_EASY_DMA) \
}
/**
* @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 clear_bus_init; ///< Clear bus during init.
bool hold_bus_uninit; ///< Hold pull up state on gpio pins after uninit.
} nrf_drv_twi_config_t;
/**
* @brief TWI master driver instance default configuration.
*/
#define NRF_DRV_TWI_DEFAULT_CONFIG \
{ \
.frequency = (nrf_twi_frequency_t)TWI_DEFAULT_CONFIG_FREQUENCY, \
.scl = 31, \
.sda = 31, \
.interrupt_priority = TWI_DEFAULT_CONFIG_IRQ_PRIORITY, \
.clear_bus_init = TWI_DEFAULT_CONFIG_CLR_BUS_INIT, \
.hold_bus_uninit = TWI_DEFAULT_CONFIG_HOLD_BUS_UNINIT, \
}
#define NRF_DRV_TWI_FLAG_TX_POSTINC (1UL << 0) /**< TX buffer address incremented after transfer. */
#define NRF_DRV_TWI_FLAG_RX_POSTINC (1UL << 1) /**< RX buffer address incremented after transfer. */
#define NRF_DRV_TWI_FLAG_NO_XFER_EVT_HANDLER (1UL << 2) /**< Interrupt after each transfer is suppressed, and the event handler is not called. */
#define NRF_DRV_TWI_FLAG_HOLD_XFER (1UL << 3) /**< Set up the transfer but do not start it. */
#define NRF_DRV_TWI_FLAG_REPEATED_XFER (1UL << 4) /**< Flag indicating that the transfer will be executed multiple times. */
#define NRF_DRV_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
{
NRF_DRV_TWI_EVT_DONE, ///< Transfer completed event.
NRF_DRV_TWI_EVT_ADDRESS_NACK, ///< Error event: NACK received after sending the address.
NRF_DRV_TWI_EVT_DATA_NACK ///< Error event: NACK received after sending a data byte.
} nrf_drv_twi_evt_type_t;
/**
* @brief TWI master driver transfer types.
*/
typedef enum
{
NRF_DRV_TWI_XFER_TX, ///< TX transfer.
NRF_DRV_TWI_XFER_RX, ///< RX transfer.
NRF_DRV_TWI_XFER_TXRX, ///< TX transfer followed by RX transfer with repeated start.
NRF_DRV_TWI_XFER_TXTX ///< TX transfer followed by TX transfer with repeated start.
} nrf_drv_twi_xfer_type_t;
/**
* @brief Structure for a TWI transfer descriptor.
*/
typedef struct
{
nrf_drv_twi_xfer_type_t type; ///< Type of transfer.
uint8_t address; ///< Slave address.
uint8_t primary_length; ///< Number of bytes transferred.
uint8_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.
} nrf_drv_twi_xfer_desc_t;
/**@brief Macro for setting the TX transfer descriptor. */
#define NRF_DRV_TWI_XFER_DESC_TX(addr, p_data, length) \
{ \
.type = NRF_DRV_TWI_XFER_TX, \
.address = addr, \
.primary_length = length, \
.p_primary_buf = p_data, \
}
/**@brief Macro for setting the RX transfer descriptor. */
#define NRF_DRV_TWI_XFER_DESC_RX(addr, p_data, length) \
{ \
.type = NRF_DRV_TWI_XFER_RX, \
.address = addr, \
.primary_length = length, \
.p_primary_buf = p_data, \
}
/**@brief Macro for setting the TXRX transfer descriptor. */
#define NRF_DRV_TWI_XFER_DESC_TXRX(addr, p_tx, tx_len, p_rx, rx_len) \
{ \
.type = NRF_DRV_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 NRF_DRV_TWI_XFER_DESC_TXTX(addr, p_tx, tx_len, p_tx2, tx_len2) \
{ \
.type = NRF_DRV_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
{
nrf_drv_twi_evt_type_t type; ///< Event type.
nrf_drv_twi_xfer_desc_t xfer_desc; ///< Transfer details.
} nrf_drv_twi_evt_t;
/**
* @brief TWI event handler prototype.
*/
typedef void (* nrf_drv_twi_evt_handler_t)(nrf_drv_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 Initial configuration. If NULL, the default configuration is used.
* @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 NRF_SUCCESS If initialization was successful.
* @retval NRF_ERROR_INVALID_STATE If the driver is in invalid state.
* @retval NRF_ERROR_BUSY If some other peripheral with the same
* instance ID is already in use. This is
* possible only if PERIPHERAL_RESOURCE_SHARING_ENABLED
* is set to a value other than zero.
*/
ret_code_t nrf_drv_twi_init(nrf_drv_twi_t const * p_instance,
nrf_drv_twi_config_t const * p_config,
nrf_drv_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 nrf_drv_twi_uninit(nrf_drv_twi_t const * p_instance);
/**
* @brief Function for enabling the TWI instance.
*
* @param[in] p_instance Pointer to the driver instance structure.
*/
void nrf_drv_twi_enable(nrf_drv_twi_t const * p_instance);
/**
* @brief Function for disabling the TWI instance.
*
* @param[in] p_instance Pointer to the driver instance structure.
*/
void nrf_drv_twi_disable(nrf_drv_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 NRF_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 NRF_SUCCESS If the procedure was successful.
* @retval NRF_ERROR_BUSY If the driver is not ready for a new transfer.
* @retval NRF_ERROR_INTERNAL If an error was detected by hardware.
* @retval NRF_ERROR_INVALID_ADDR If the EasyDMA is used and memory adress in not in RAM.
* @retval NRF_ERROR_DRV_TWI_ERR_ANACK If NACK received after sending the address in polling mode.
* @retval NRF_ERROR_DRV_TWI_ERR_DNACK If NACK received after sending a data byte in polling mode.
*/
ret_code_t nrf_drv_twi_tx(nrf_drv_twi_t const * p_instance,
uint8_t address,
uint8_t const * p_data,
uint8_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 NRF_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 NRF_SUCCESS If the procedure was successful.
* @retval NRF_ERROR_BUSY If the driver is not ready for a new transfer.
* @retval NRF_ERROR_INTERNAL If an error was detected by hardware.
* @retval NRF_ERROR_DRV_TWI_ERR_OVERRUN If the unread data was replaced by new data
* @retval NRF_ERROR_DRV_TWI_ERR_ANACK If NACK received after sending the address in polling mode.
* @retval NRF_ERROR_DRV_TWI_ERR_DNACK If NACK received after sending a data byte in polling mode.
*/
ret_code_t nrf_drv_twi_rx(nrf_drv_twi_t const * p_instance,
uint8_t address,
uint8_t * p_data,
uint8_t length);
/**
* @brief Function for preparing a TWI transfer.
*
* The following transfer types can be configured (@ref nrf_drv_twi_xfer_desc_t::type):
* - @ref NRF_DRV_TWI_XFER_TXRX: Write operation followed by a read operation (without STOP condition in between).
* - @ref NRF_DRV_TWI_XFER_TXTX: Write operation followed by a write operation (without STOP condition in between).
* - @ref NRF_DRV_TWI_XFER_TX: Write operation (with or without STOP condition).
* - @ref NRF_DRV_TWI_XFER_RX: Read operation (with STOP condition).
*
* Additional options are provided using the flags parameter:
* - @ref NRF_DRV_TWI_FLAG_TX_POSTINC and @ref NRF_DRV_TWI_FLAG_RX_POSTINC: Post-incrementation of buffer addresses. Supported only by TWIM.
* - @ref NRF_DRV_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 NRF_DRV_TWI_FLAG_HOLD_XFER: Driver is not starting the transfer. Use this flag if the transfer is triggered externally by PPI. Supported only by TWIM.
* Use @ref nrf_drv_twi_start_task_get to get the address of the start task.
* - @ref NRF_DRV_TWI_FLAG_REPEATED_XFER: Prepare for repeated transfers. You can set up a number of transfers that will be triggered externally (for example by PPI).
* An example is a TXRX transfer with the options @ref NRF_DRV_TWI_FLAG_RX_POSTINC, @ref NRF_DRV_TWI_FLAG_NO_XFER_EVT_HANDLER, and @ref NRF_DRV_TWI_FLAG_REPEATED_XFER.
* After the transfer is set up, a set of transfers can be triggered by PPI that will read, for example, the same register of an
* external component and put it into a RAM buffer without any interrupts. @ref nrf_drv_twi_stopped_event_get can be used to get the
* address of the STOPPED event, which can be used to count the number of transfers. If @ref NRF_DRV_TWI_FLAG_REPEATED_XFER is used,
* the driver does not set the driver instance into busy state, so you must ensure that the next transfers are set up
* when TWIM is not active. Supported only by TWIM.
* - @ref NRF_DRV_TWI_FLAG_TX_NO_STOP: No stop condition after TX transfer.
*
* @note
* Some flag combinations are invalid:
* - @ref NRF_DRV_TWI_FLAG_TX_NO_STOP with @ref nrf_drv_twi_xfer_desc_t::type different than @ref NRF_DRV_TWI_XFER_TX
* - @ref NRF_DRV_TWI_FLAG_REPEATED_XFER with @ref nrf_drv_twi_xfer_desc_t::type set to @ref NRF_DRV_TWI_XFER_TXTX
*
* If @ref nrf_drv_twi_xfer_desc_t::type is set to @ref NRF_DRV_TWI_XFER_TX and the @ref NRF_DRV_TWI_FLAG_TX_NO_STOP and @ref NRF_DRV_TWI_FLAG_REPEATED_XFER
* flags are set, two tasks must be used to trigger a transfer: TASKS_RESUME followed by TASKS_STARTTX. If no stop condition is generated,
* TWIM is in SUSPENDED state. Therefore, it must be resumed before the transfer can be started.
*
* @note
* This function should be used only if the instance is configured to work in non-blocking mode. If the function is used in blocking mode, the driver asserts.
* @note If you are using this function with TWI, the only supported flag is @ref NRF_DRV_TWI_FLAG_TX_NO_STOP. All other flags require TWIM.
*
* @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 NRF_SUCCESS If the procedure was successful.
* @retval NRF_ERROR_BUSY If the driver is not ready for a new transfer.
* @retval NRF_ERROR_NOT_SUPPORTED If the provided parameters are not supported.
* @retval NRF_ERROR_INTERNAL If an error was detected by hardware.
* @retval NRF_ERROR_INVALID_ADDR If the EasyDMA is used and memory adress in not in RAM
* @retval NRF_ERROR_DRV_TWI_ERR_OVERRUN If the unread data was replaced by new data (TXRX and RX)
* @retval NRF_ERROR_DRV_TWI_ERR_ANACK If NACK received after sending the address.
* @retval NRF_ERROR_DRV_TWI_ERR_DNACK If NACK received after sending a data byte.
*/
ret_code_t nrf_drv_twi_xfer(nrf_drv_twi_t const * p_instance,
nrf_drv_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 nrf_drv_twi_is_busy(nrf_drv_twi_t const * p_instance);
/**
* @brief Function for getting the transferred data count.
*
* This function provides valid results only in legacy mode.
*
* @param[in] p_instance Pointer to the driver instance structure.
*
* @return Data count.
*/
uint32_t nrf_drv_twi_data_count_get(nrf_drv_twi_t const * const p_instance);
/**
* @brief Function for returning the address of a TWI/TWIM start task.
*
* This function should be used if @ref nrf_drv_twi_xfer was called with the flag @ref NRF_DRV_TWI_FLAG_HOLD_XFER.
* In that case, the transfer is not started by the driver, but it must be started externally by PPI.
*
* @param[in] p_instance Pointer to the driver instance structure.
* @param[in] xfer_type Transfer type used in the last call of the @ref nrf_drv_twi_xfer function.
*
* @return Start task address (TX or RX) depending on the value of xfer_type.
*/
uint32_t nrf_drv_twi_start_task_get(nrf_drv_twi_t const * p_instance, nrf_drv_twi_xfer_type_t xfer_type);
/**
* @brief Function for returning the address of a STOPPED TWI/TWIM event.
*
* A STOPPED event can be used to detect the end of a transfer if the @ref NRF_DRV_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 nrf_drv_twi_stopped_event_get(nrf_drv_twi_t const * p_instance);
/**
*@}
**/
#ifdef __cplusplus
}
#endif
#endif // NRF_DRV_TWI_H__