nrfx/hal/nrf_twi.h

/*
 * 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
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef NRF_TWI_H__
#define NRF_TWI_H__

#include <nrfx.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @defgroup nrf_twi_hal TWI HAL
 * @{
 * @ingroup nrf_twi
 * @brief   Hardware access layer for managing the TWI peripheral.
 */

/** @brief TWI tasks. */
typedef enum
{
    NRF_TWI_TASK_STARTRX = offsetof(NRF_TWI_Type, TASKS_STARTRX), ///< Start TWI receive sequence.
    NRF_TWI_TASK_STARTTX = offsetof(NRF_TWI_Type, TASKS_STARTTX), ///< Start TWI transmit sequence.
    NRF_TWI_TASK_STOP    = offsetof(NRF_TWI_Type, TASKS_STOP),    ///< Stop TWI transaction.
    NRF_TWI_TASK_SUSPEND = offsetof(NRF_TWI_Type, TASKS_SUSPEND), ///< Suspend TWI transaction.
    NRF_TWI_TASK_RESUME  = offsetof(NRF_TWI_Type, TASKS_RESUME)   ///< Resume TWI transaction.
} nrf_twi_task_t;

/** @brief TWI events. */
typedef enum
{
    NRF_TWI_EVENT_STOPPED   = offsetof(NRF_TWI_Type, EVENTS_STOPPED),  ///< TWI stopped.
    NRF_TWI_EVENT_RXDREADY  = offsetof(NRF_TWI_Type, EVENTS_RXDREADY), ///< TWI RXD byte received.
    NRF_TWI_EVENT_TXDSENT   = offsetof(NRF_TWI_Type, EVENTS_TXDSENT),  ///< TWI TXD byte sent.
    NRF_TWI_EVENT_ERROR     = offsetof(NRF_TWI_Type, EVENTS_ERROR),    ///< TWI error.
    NRF_TWI_EVENT_BB        = offsetof(NRF_TWI_Type, EVENTS_BB),       ///< TWI byte boundary, generated before each byte that is sent or received.
    NRF_TWI_EVENT_SUSPENDED = offsetof(NRF_TWI_Type, EVENTS_SUSPENDED) ///< TWI entered the suspended state.
} nrf_twi_event_t;

/** @brief TWI shortcuts. */
typedef enum
{
    NRF_TWI_SHORT_BB_SUSPEND_MASK = TWI_SHORTS_BB_SUSPEND_Msk,  ///< Shortcut between BB event and SUSPEND task.
    NRF_TWI_SHORT_BB_STOP_MASK    = TWI_SHORTS_BB_STOP_Msk,     ///< Shortcut between BB event and STOP task.
    NRF_TWI_ALL_SHORTS_MASK       = TWI_SHORTS_BB_SUSPEND_Msk |
                                    TWI_SHORTS_BB_STOP_Msk      ///< All TWI shortcuts.
} nrf_twi_short_mask_t;

/** @brief TWI interrupts. */
typedef enum
{
    NRF_TWI_INT_STOPPED_MASK    = TWI_INTENSET_STOPPED_Msk,    ///< Interrupt on STOPPED event.
    NRF_TWI_INT_RXDREADY_MASK   = TWI_INTENSET_RXDREADY_Msk,   ///< Interrupt on RXDREADY event.
    NRF_TWI_INT_TXDSENT_MASK    = TWI_INTENSET_TXDSENT_Msk,    ///< Interrupt on TXDSENT event.
    NRF_TWI_INT_ERROR_MASK      = TWI_INTENSET_ERROR_Msk,      ///< Interrupt on ERROR event.
    NRF_TWI_INT_BB_MASK         = TWI_INTENSET_BB_Msk,         ///< Interrupt on BB event.
    NRF_TWI_INT_SUSPENDED_MASK  = TWI_INTENSET_SUSPENDED_Msk,  ///< Interrupt on SUSPENDED event.
    NRF_TWI_ALL_INTS_MASK       = TWI_INTENSET_STOPPED_Msk   |
                                  TWI_INTENSET_RXDREADY_Msk  |
                                  TWI_INTENSET_TXDSENT_Msk   |
                                  TWI_INTENSET_ERROR_Msk     |
                                  TWI_INTENSET_BB_Msk        |
                                  TWI_INTENSET_SUSPENDED_Msk   ///< All TWI interrupts.
} nrf_twi_int_mask_t;

/** @brief TWI error source. */
typedef enum
{
    NRF_TWI_ERROR_ADDRESS_NACK = TWI_ERRORSRC_ANACK_Msk,  ///< NACK received after sending the address.
    NRF_TWI_ERROR_DATA_NACK    = TWI_ERRORSRC_DNACK_Msk,  ///< NACK received after sending a data byte.
    NRF_TWI_ERROR_OVERRUN      = TWI_ERRORSRC_OVERRUN_Msk ///< Overrun error.
                                                          /**< A new byte was received before the previous byte was read
                                                           *   from the RXD register (previous data is lost). */
} nrf_twi_error_t;

/** @brief TWI master clock frequency. */
typedef enum
{
    NRF_TWI_FREQ_100K = TWI_FREQUENCY_FREQUENCY_K100, ///< 100 kbps.
    NRF_TWI_FREQ_250K = TWI_FREQUENCY_FREQUENCY_K250, ///< 250 kbps.
    NRF_TWI_FREQ_400K = TWI_FREQUENCY_FREQUENCY_K400  ///< 400 kbps.
} nrf_twi_frequency_t;


/**
 * @brief Function for activating the specified TWI task.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] task  Task to be activated.
 */
NRF_STATIC_INLINE void nrf_twi_task_trigger(NRF_TWI_Type * p_reg,
                                            nrf_twi_task_t task);

/**
 * @brief Function for getting the address of the specified TWI task register.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] task  The specified task.
 *
 * @return Address of the specified task register.
 */
NRF_STATIC_INLINE uint32_t nrf_twi_task_address_get(NRF_TWI_Type const * p_reg,
                                                    nrf_twi_task_t       task);

/**
 * @brief Function for clearing the specified TWI event.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] event Event to clear.
 */
NRF_STATIC_INLINE void nrf_twi_event_clear(NRF_TWI_Type *  p_reg,
                                           nrf_twi_event_t event);

/**
 * @brief Function for retrieving the state of the TWI event.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] event Event to be checked.
 *
 * @retval true  The event has been generated.
 * @retval false The event has not been generated.
 */
NRF_STATIC_INLINE bool nrf_twi_event_check(NRF_TWI_Type const * p_reg,
                                           nrf_twi_event_t      event);

/**
 * @brief Function for getting the address of the specified TWI event register.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] event The specified event.
 *
 * @return Address of the specified event register.
 */
NRF_STATIC_INLINE uint32_t nrf_twi_event_address_get(NRF_TWI_Type const * p_reg,
                                                     nrf_twi_event_t      event);

/**
 * @brief Function for enabling the specified shortcuts.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] mask  Shortcuts to be enabled.
 */
NRF_STATIC_INLINE void nrf_twi_shorts_enable(NRF_TWI_Type * p_reg,
                                             uint32_t       mask);

/**
 * @brief Function for disabling the specified shortcuts.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] mask  Shortcuts to be disabled.
 */
NRF_STATIC_INLINE void nrf_twi_shorts_disable(NRF_TWI_Type * p_reg,
                                              uint32_t       mask);

/**
 * @brief Function for enabling the specified interrupts.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] mask  Mask of interrupts to be enabled.
 */
NRF_STATIC_INLINE void nrf_twi_int_enable(NRF_TWI_Type * p_reg,
                                          uint32_t       mask);

/**
 * @brief Function for disabling the specified interrupts.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] mask  Mask of interrupts to be disabled.
 */
NRF_STATIC_INLINE void nrf_twi_int_disable(NRF_TWI_Type * p_reg,
                                           uint32_t       mask);

/**
 * @brief Function for checking if the specified interrupts are enabled.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] mask  Mask of interrupts to be checked.
 *
 * @return Mask of enabled interrupts.
 */
NRF_STATIC_INLINE uint32_t nrf_twi_int_enable_check(NRF_TWI_Type const * p_reg, uint32_t mask);

/**
 * @brief Function for enabling the TWI peripheral.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 */
NRF_STATIC_INLINE void nrf_twi_enable(NRF_TWI_Type * p_reg);

/**
 * @brief Function for disabling the TWI peripheral.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 */
NRF_STATIC_INLINE void nrf_twi_disable(NRF_TWI_Type * p_reg);

/**
 * @brief Function for configuring TWI pins.
 *
 * @param[in] p_reg   Pointer to the structure of registers of the peripheral.
 * @param[in] scl_pin SCL pin number.
 * @param[in] sda_pin SDA pin number.
 */
NRF_STATIC_INLINE void nrf_twi_pins_set(NRF_TWI_Type * p_reg,
                                        uint32_t       scl_pin,
                                        uint32_t       sda_pin);

/**
 * @brief Function for retrieving the SCL pin selection.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 *
 * @return SCL pin selection.
 */
NRF_STATIC_INLINE uint32_t nrf_twi_scl_pin_get(NRF_TWI_Type const * p_reg);

/**
 * @brief Function for retrieving the SDA pin selection.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 *
 * @return SDA pin selection.
 */
NRF_STATIC_INLINE uint32_t nrf_twi_sda_pin_get(NRF_TWI_Type const * p_reg);

/**
 * @brief Function for setting the TWI master clock frequency.
 *
 * @param[in] p_reg     Pointer to the structure of registers of the peripheral.
 * @param[in] frequency TWI frequency.
 */
NRF_STATIC_INLINE void nrf_twi_frequency_set(NRF_TWI_Type *      p_reg,
                                             nrf_twi_frequency_t frequency);

/**
 * @brief Function for checking the TWI error source.
 *
 * The error flags are cleared after reading.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 *
 * @return Mask with error source flags.
 */
NRF_STATIC_INLINE uint32_t nrf_twi_errorsrc_get_and_clear(NRF_TWI_Type * p_reg);

/**
 * @brief Function for setting the address to be used in TWI transfers.
 *
 * @param[in] p_reg   Pointer to the structure of registers of the peripheral.
 * @param[in] address Address to be used in transfers.
 */
NRF_STATIC_INLINE void nrf_twi_address_set(NRF_TWI_Type * p_reg, uint8_t address);

/**
 * @brief Function for reading data received by TWI.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 *
 * @return Received data.
 */
NRF_STATIC_INLINE uint8_t nrf_twi_rxd_get(NRF_TWI_Type const * p_reg);

/**
 * @brief Function for writing data to be transmitted by TWI.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] data  Data to be transmitted.
 */
NRF_STATIC_INLINE void nrf_twi_txd_set(NRF_TWI_Type * p_reg, uint8_t data);

/**
 * @brief Function for setting the specified shortcuts.
 *
 * @param[in] p_reg Pointer to the structure of registers of the peripheral.
 * @param[in] mask  Shortcuts to be set.
 */
NRF_STATIC_INLINE void nrf_twi_shorts_set(NRF_TWI_Type * p_reg,
                                          uint32_t       mask);

#ifndef NRF_DECLARE_ONLY

NRF_STATIC_INLINE void nrf_twi_task_trigger(NRF_TWI_Type * p_reg,
                                            nrf_twi_task_t task)
{
    *((volatile uint32_t *)((uint8_t *)p_reg + (uint32_t)task)) = 0x1UL;
}

NRF_STATIC_INLINE uint32_t nrf_twi_task_address_get(NRF_TWI_Type const * p_reg,
                                                    nrf_twi_task_t       task)
{
    return (uint32_t)((uint8_t *)p_reg + (uint32_t)task);
}

NRF_STATIC_INLINE void nrf_twi_event_clear(NRF_TWI_Type  * p_reg,
                                           nrf_twi_event_t event)
{
    *((volatile uint32_t *)((uint8_t *)p_reg + (uint32_t)event)) = 0x0UL;
    nrf_event_readback((uint8_t *)p_reg + (uint32_t)event);
}

NRF_STATIC_INLINE bool nrf_twi_event_check(NRF_TWI_Type const * p_reg,
                                           nrf_twi_event_t      event)
{
    return (bool)*(volatile uint32_t *)((uint8_t *)p_reg + (uint32_t)event);
}

NRF_STATIC_INLINE uint32_t nrf_twi_event_address_get(NRF_TWI_Type const * p_reg,
                                                     nrf_twi_event_t      event)
{
    return (uint32_t)((uint8_t *)p_reg + (uint32_t)event);
}

NRF_STATIC_INLINE void nrf_twi_shorts_enable(NRF_TWI_Type * p_reg,
                                             uint32_t       mask)
{
    p_reg->SHORTS |= mask;
}

NRF_STATIC_INLINE void nrf_twi_shorts_disable(NRF_TWI_Type * p_reg,
                                              uint32_t       mask)
{
    p_reg->SHORTS &= ~(mask);
}

NRF_STATIC_INLINE void nrf_twi_int_enable(NRF_TWI_Type * p_reg,
                                          uint32_t       mask)
{
    p_reg->INTENSET = mask;
}

NRF_STATIC_INLINE void nrf_twi_int_disable(NRF_TWI_Type * p_reg,
                                           uint32_t       mask)
{
    p_reg->INTENCLR = mask;
}

NRF_STATIC_INLINE uint32_t nrf_twi_int_enable_check(NRF_TWI_Type const * p_reg, uint32_t mask)
{
    return p_reg->INTENSET & mask;
}

NRF_STATIC_INLINE void nrf_twi_enable(NRF_TWI_Type * p_reg)
{
    p_reg->ENABLE = (TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos);
}

NRF_STATIC_INLINE void nrf_twi_disable(NRF_TWI_Type * p_reg)
{
    p_reg->ENABLE = (TWI_ENABLE_ENABLE_Disabled << TWI_ENABLE_ENABLE_Pos);
}

NRF_STATIC_INLINE void nrf_twi_pins_set(NRF_TWI_Type * p_reg,
                                        uint32_t       scl_pin,
                                        uint32_t       sda_pin)
{
#if defined(TWI_PSEL_SCL_CONNECT_Pos)
    p_reg->PSEL.SCL = scl_pin;
#else
    p_reg->PSELSCL = scl_pin;
#endif

#if defined(TWI_PSEL_SDA_CONNECT_Pos)
    p_reg->PSEL.SDA = sda_pin;
#else
    p_reg->PSELSDA = sda_pin;
#endif
}

NRF_STATIC_INLINE uint32_t nrf_twi_scl_pin_get(NRF_TWI_Type const * p_reg)
{
#if defined(TWI_PSEL_SCL_CONNECT_Pos)
    return p_reg->PSEL.SCL;
#else
    return p_reg->PSELSCL;
#endif
}

NRF_STATIC_INLINE uint32_t nrf_twi_sda_pin_get(NRF_TWI_Type const * p_reg)
{
#if defined(TWI_PSEL_SDA_CONNECT_Pos)
    return p_reg->PSEL.SDA;
#else
    return p_reg->PSELSDA;
#endif
}

NRF_STATIC_INLINE void nrf_twi_frequency_set(NRF_TWI_Type *      p_reg,
                                             nrf_twi_frequency_t frequency)
{
    p_reg->FREQUENCY = frequency;
}

NRF_STATIC_INLINE uint32_t nrf_twi_errorsrc_get_and_clear(NRF_TWI_Type * p_reg)
{
    uint32_t error_source = p_reg->ERRORSRC;

    // [error flags are cleared by writing '1' on their position]
    p_reg->ERRORSRC = error_source;

    return error_source;
}

NRF_STATIC_INLINE void nrf_twi_address_set(NRF_TWI_Type * p_reg, uint8_t address)
{
    p_reg->ADDRESS = address;
}

NRF_STATIC_INLINE uint8_t nrf_twi_rxd_get(NRF_TWI_Type const * p_reg)
{
    return (uint8_t)p_reg->RXD;
}

NRF_STATIC_INLINE void nrf_twi_txd_set(NRF_TWI_Type * p_reg, uint8_t data)
{
    p_reg->TXD = data;
}

NRF_STATIC_INLINE void nrf_twi_shorts_set(NRF_TWI_Type * p_reg,
                                          uint32_t       mask)
{
    p_reg->SHORTS = mask;
}

#endif // NRF_DECLARE_ONLY

/** @} */

#ifdef __cplusplus
}
#endif

#endif // NRF_TWI_H__