/*
 * 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.
 */

#include <nrfx.h>

#if NRFX_CHECK(NRFX_TWIM_ENABLED)

#if !(NRFX_CHECK(NRFX_TWIM0_ENABLED) || \
      NRFX_CHECK(NRFX_TWIM1_ENABLED) || \
      NRFX_CHECK(NRFX_TWIM2_ENABLED) || \
      NRFX_CHECK(NRFX_TWIM3_ENABLED))
#error "No enabled TWIM instances. Check <nrfx_config.h>."
#endif

#include <nrfx_twim.h>
#include <hal/nrf_gpio.h>
#include "prs/nrfx_prs.h"

#define NRFX_LOG_MODULE TWIM
#include <nrfx_log.h>

#define EVT_TO_STR(event)                                       \
    (event == NRFX_TWIM_EVT_DONE         ? "EVT_DONE"         : \
    (event == NRFX_TWIM_EVT_ADDRESS_NACK ? "EVT_ADDRESS_NACK" : \
    (event == NRFX_TWIM_EVT_DATA_NACK    ? "EVT_DATA_NACK"    : \
    (event == NRFX_TWIM_EVT_OVERRUN      ? "EVT_OVERRUN"      : \
    (event == NRFX_TWIM_EVT_BUS_ERROR    ? "EVT_BUS_ERROR"    : \
                                           "UNKNOWN ERROR")))))

#define EVT_TO_STR_TWIM(event)                                        \
    (event == NRF_TWIM_EVENT_STOPPED   ? "NRF_TWIM_EVENT_STOPPED"   : \
    (event == NRF_TWIM_EVENT_ERROR     ? "NRF_TWIM_EVENT_ERROR"     : \
    (event == NRF_TWIM_EVENT_SUSPENDED ? "NRF_TWIM_EVENT_SUSPENDED" : \
    (event == NRF_TWIM_EVENT_RXSTARTED ? "NRF_TWIM_EVENT_RXSTARTED" : \
    (event == NRF_TWIM_EVENT_TXSTARTED ? "NRF_TWIM_EVENT_TXSTARTED" : \
    (event == NRF_TWIM_EVENT_LASTRX    ? "NRF_TWIM_EVENT_LASTRX"    : \
    (event == NRF_TWIM_EVENT_LASTTX    ? "NRF_TWIM_EVENT_LASTTX"    : \
                                         "UNKNOWN ERROR")))))))

#define TRANSFER_TO_STR(type)                    \
    (type == NRFX_TWIM_XFER_TX   ? "XFER_TX"   : \
    (type == NRFX_TWIM_XFER_RX   ? "XFER_RX"   : \
    (type == NRFX_TWIM_XFER_TXRX ? "XFER_TXRX" : \
    (type == NRFX_TWIM_XFER_TXTX ? "XFER_TXTX" : \
                                   "UNKNOWN TRANSFER TYPE"))))

#define TWIM_PIN_INIT(_pin) nrf_gpio_cfg((_pin),                     \
                                         NRF_GPIO_PIN_DIR_INPUT,     \
                                         NRF_GPIO_PIN_INPUT_CONNECT, \
                                         NRF_GPIO_PIN_PULLUP,        \
                                         NRF_GPIO_PIN_S0D1,          \
                                         NRF_GPIO_PIN_NOSENSE)

#define TWIMX_LENGTH_VALIDATE(peripheral, drv_inst_idx, len1, len2)     \
    (((drv_inst_idx) == NRFX_CONCAT_3(NRFX_, peripheral, _INST_IDX)) && \
     NRFX_EASYDMA_LENGTH_VALIDATE(peripheral, len1, len2))

#if NRFX_CHECK(NRFX_TWIM0_ENABLED)
#define TWIM0_LENGTH_VALIDATE(...)  TWIMX_LENGTH_VALIDATE(TWIM0, __VA_ARGS__)
#else
#define TWIM0_LENGTH_VALIDATE(...)  0
#endif

#if NRFX_CHECK(NRFX_TWIM1_ENABLED)
#define TWIM1_LENGTH_VALIDATE(...)  TWIMX_LENGTH_VALIDATE(TWIM1, __VA_ARGS__)
#else
#define TWIM1_LENGTH_VALIDATE(...)  0
#endif

#if NRFX_CHECK(NRFX_TWIM2_ENABLED)
#define TWIM2_LENGTH_VALIDATE(...)  TWIMX_LENGTH_VALIDATE(TWIM2, __VA_ARGS__)
#else
#define TWIM2_LENGTH_VALIDATE(...)  0
#endif

#if NRFX_CHECK(NRFX_TWIM3_ENABLED)
#define TWIM3_LENGTH_VALIDATE(...)  TWIMX_LENGTH_VALIDATE(TWIM3, __VA_ARGS__)
#else
#define TWIM3_LENGTH_VALIDATE(...)  0
#endif

#define TWIM_LENGTH_VALIDATE(drv_inst_idx, len1, len2)  \
    (TWIM0_LENGTH_VALIDATE(drv_inst_idx, len1, len2) || \
     TWIM1_LENGTH_VALIDATE(drv_inst_idx, len1, len2) || \
     TWIM2_LENGTH_VALIDATE(drv_inst_idx, len1, len2) || \
     TWIM3_LENGTH_VALIDATE(drv_inst_idx, len1, len2))

// Control block - driver instance local data.
typedef struct
{
    nrfx_twim_evt_handler_t handler;
    void *                  p_context;
    volatile uint32_t       int_mask;
    nrfx_twim_xfer_desc_t   xfer_desc;
    uint32_t                flags;
    uint8_t *               p_curr_buf;
    size_t                  curr_length;
    bool                    curr_no_stop;
    nrfx_drv_state_t        state;
    bool                    error;
    volatile bool           busy;
    bool                    repeated;
    uint8_t                 bytes_transferred;
    bool                    hold_bus_uninit;
#if NRFX_CHECK(NRFX_TWIM_NRF52_ANOMALY_109_WORKAROUND_ENABLED)
    nrf_twim_frequency_t    bus_frequency;
#endif
} twim_control_block_t;

static twim_control_block_t m_cb[NRFX_TWIM_ENABLED_COUNT];

static nrfx_err_t twi_process_error(uint32_t errorsrc)
{
    nrfx_err_t ret = NRFX_ERROR_INTERNAL;

    if (errorsrc & NRF_TWIM_ERROR_OVERRUN)
    {
        ret = NRFX_ERROR_DRV_TWI_ERR_OVERRUN;
    }

    if (errorsrc & NRF_TWIM_ERROR_ADDRESS_NACK)
    {
        ret = NRFX_ERROR_DRV_TWI_ERR_ANACK;
    }

    if (errorsrc & NRF_TWIM_ERROR_DATA_NACK)
    {
        ret = NRFX_ERROR_DRV_TWI_ERR_DNACK;
    }

    return ret;
}

static bool xfer_completeness_check(NRF_TWIM_Type * p_twim, twim_control_block_t const * p_cb)
{
    // If the actual number of transferred bytes is not equal to what was requested,
    // but there was no error signaled by the peripheral, this means that something
    // unexpected, like a premature STOP condition, was received on the bus.
    // In such case the peripheral has to be disabled and re-enabled, so that its
    // internal state machine is reinitialized.

    bool transfer_complete = true;
    switch (p_cb->xfer_desc.type)
    {
    case NRFX_TWIM_XFER_TXTX:
            // int_mask variable is used to determine which length should be checked
            // against number of bytes latched in EasyDMA.
            // NRF_TWIM_INT_SUSPENDED_MASK is configured only in first TX of TXTX transfer.
            if (((p_cb->int_mask & NRF_TWIM_INT_SUSPENDED_MASK) &&
                 (nrf_twim_txd_amount_get(p_twim) != p_cb->xfer_desc.primary_length)) ||
                (!(p_cb->int_mask & NRF_TWIM_INT_SUSPENDED_MASK) &&
                 (nrf_twim_txd_amount_get(p_twim) != p_cb->xfer_desc.secondary_length)))
            {
                transfer_complete = false;
            }
        break;
    case NRFX_TWIM_XFER_TXRX:
            if ((nrf_twim_txd_amount_get(p_twim) != p_cb->xfer_desc.primary_length) ||
                (nrf_twim_rxd_amount_get(p_twim) != p_cb->xfer_desc.secondary_length))
            {
                transfer_complete = false;
            }
        break;
    case NRFX_TWIM_XFER_TX:
            if (nrf_twim_txd_amount_get(p_twim) != p_cb->xfer_desc.primary_length)
            {
                transfer_complete = false;
            }
        break;
    case NRFX_TWIM_XFER_RX:
            if (nrf_twim_rxd_amount_get(p_twim) != p_cb->xfer_desc.primary_length)
            {
                transfer_complete = false;
            }
        break;
    default:
        break;
    }

    if (!transfer_complete)
    {
        nrf_twim_disable(p_twim);
        nrf_twim_enable(p_twim);
    }

    return transfer_complete;
}

nrfx_err_t nrfx_twim_init(nrfx_twim_t const *        p_instance,
                          nrfx_twim_config_t const * p_config,
                          nrfx_twim_evt_handler_t    event_handler,
                          void *                     p_context)
{
    NRFX_ASSERT(p_config);
    NRFX_ASSERT(p_config->scl != p_config->sda);
    twim_control_block_t * p_cb  = &m_cb[p_instance->drv_inst_idx];
    nrfx_err_t err_code;

    if (p_cb->state != NRFX_DRV_STATE_UNINITIALIZED)
    {
        err_code = NRFX_ERROR_INVALID_STATE;
        NRFX_LOG_WARNING("Function: %s, error code: %s.",
                         __func__,
                         NRFX_LOG_ERROR_STRING_GET(err_code));
        return err_code;
    }

#if NRFX_CHECK(NRFX_PRS_ENABLED)
    static nrfx_irq_handler_t const irq_handlers[NRFX_TWIM_ENABLED_COUNT] = {
        #if NRFX_CHECK(NRFX_TWIM0_ENABLED)
        nrfx_twim_0_irq_handler,
        #endif
        #if NRFX_CHECK(NRFX_TWIM1_ENABLED)
        nrfx_twim_1_irq_handler,
        #endif
        #if NRFX_CHECK(NRFX_TWIM2_ENABLED)
        nrfx_twim_2_irq_handler,
        #endif
        #if NRFX_CHECK(NRFX_TWIM3_ENABLED)
        nrfx_twim_3_irq_handler,
        #endif
    };
    if (nrfx_prs_acquire(p_instance->p_twim,
            irq_handlers[p_instance->drv_inst_idx]) != NRFX_SUCCESS)
    {
        err_code = NRFX_ERROR_BUSY;
        NRFX_LOG_WARNING("Function: %s, error code: %s.",
                         __func__,
                         NRFX_LOG_ERROR_STRING_GET(err_code));
        return err_code;
    }
#endif // NRFX_CHECK(NRFX_PRS_ENABLED)

    p_cb->handler         = event_handler;
    p_cb->p_context       = p_context;
    p_cb->int_mask        = 0;
    p_cb->repeated        = false;
    p_cb->busy            = false;
    p_cb->hold_bus_uninit = p_config->hold_bus_uninit;
#if NRFX_CHECK(NRFX_TWIM_NRF52_ANOMALY_109_WORKAROUND_ENABLED)
    p_cb->bus_frequency   = (nrf_twim_frequency_t)p_config->frequency;
#endif

    /* To secure correct signal levels on the pins used by the TWI
       master when the system is in OFF mode, and when the TWI master is
       disabled, these pins must be configured in the GPIO peripheral.
    */
    TWIM_PIN_INIT(p_config->scl);
    TWIM_PIN_INIT(p_config->sda);

    NRF_TWIM_Type * p_twim = p_instance->p_twim;
    nrf_twim_pins_set(p_twim, p_config->scl, p_config->sda);
    nrf_twim_frequency_set(p_twim,
        (nrf_twim_frequency_t)p_config->frequency);

    if (p_cb->handler)
    {
        NRFX_IRQ_PRIORITY_SET(nrfx_get_irq_number(p_instance->p_twim),
            p_config->interrupt_priority);
        NRFX_IRQ_ENABLE(nrfx_get_irq_number(p_instance->p_twim));
    }

    p_cb->state = NRFX_DRV_STATE_INITIALIZED;

    err_code = NRFX_SUCCESS;
    NRFX_LOG_INFO("Function: %s, error code: %s.", __func__, NRFX_LOG_ERROR_STRING_GET(err_code));
    return err_code;
}

void nrfx_twim_uninit(nrfx_twim_t const * p_instance)
{
    twim_control_block_t * p_cb = &m_cb[p_instance->drv_inst_idx];
    NRFX_ASSERT(p_cb->state != NRFX_DRV_STATE_UNINITIALIZED);

    if (p_cb->handler)
    {
        NRFX_IRQ_DISABLE(nrfx_get_irq_number(p_instance->p_twim));
    }
    nrfx_twim_disable(p_instance);

#if NRFX_CHECK(NRFX_PRS_ENABLED)
    nrfx_prs_release(p_instance->p_twim);
#endif

    if (!p_cb->hold_bus_uninit)
    {
        nrf_gpio_cfg_default(nrf_twim_scl_pin_get(p_instance->p_twim));
        nrf_gpio_cfg_default(nrf_twim_sda_pin_get(p_instance->p_twim));
    }

    p_cb->state = NRFX_DRV_STATE_UNINITIALIZED;
    NRFX_LOG_INFO("Instance uninitialized: %d.", p_instance->drv_inst_idx);
}

void nrfx_twim_enable(nrfx_twim_t const * p_instance)
{
    twim_control_block_t * p_cb = &m_cb[p_instance->drv_inst_idx];
    NRFX_ASSERT(p_cb->state == NRFX_DRV_STATE_INITIALIZED);

    nrf_twim_enable(p_instance->p_twim);

    p_cb->state = NRFX_DRV_STATE_POWERED_ON;
    NRFX_LOG_INFO("Instance enabled: %d.", p_instance->drv_inst_idx);
}

void nrfx_twim_disable(nrfx_twim_t const * p_instance)
{
    twim_control_block_t * p_cb = &m_cb[p_instance->drv_inst_idx];
    NRFX_ASSERT(p_cb->state != NRFX_DRV_STATE_UNINITIALIZED);

    NRF_TWIM_Type * p_twim = p_instance->p_twim;
    p_cb->int_mask = 0;
    nrf_twim_int_disable(p_twim, NRF_TWIM_ALL_INTS_MASK);
    nrf_twim_shorts_disable(p_twim, NRF_TWIM_ALL_SHORTS_MASK);
    nrf_twim_disable(p_twim);

    p_cb->state = NRFX_DRV_STATE_INITIALIZED;
    NRFX_LOG_INFO("Instance disabled: %d.", p_instance->drv_inst_idx);
}


bool nrfx_twim_is_busy(nrfx_twim_t const * p_instance)
{
    twim_control_block_t * p_cb = &m_cb[p_instance->drv_inst_idx];
    return p_cb->busy;
}


static void twim_list_enable_handle(NRF_TWIM_Type * p_twim, uint32_t flags)
{
    if (NRFX_TWIM_FLAG_TX_POSTINC & flags)
    {
        nrf_twim_tx_list_enable(p_twim);
    }
    else
    {
        nrf_twim_tx_list_disable(p_twim);
    }

    if (NRFX_TWIM_FLAG_RX_POSTINC & flags)
    {
        nrf_twim_rx_list_enable(p_twim);
    }
    else
    {
        nrf_twim_rx_list_disable(p_twim);
    }
}
static nrfx_err_t twim_xfer(twim_control_block_t        * p_cb,
                            NRF_TWIM_Type               * p_twim,
                            nrfx_twim_xfer_desc_t const * p_xfer_desc,
                            uint32_t                      flags)
{
    nrfx_err_t err_code = NRFX_SUCCESS;
    nrf_twim_task_t  start_task = NRF_TWIM_TASK_STARTTX;
    p_cb->error = false;

    if (!nrfx_is_in_ram(p_xfer_desc->p_primary_buf))
    {
        err_code = NRFX_ERROR_INVALID_ADDR;
        NRFX_LOG_WARNING("Function: %s, error code: %s.",
                         __func__,
                         NRFX_LOG_ERROR_STRING_GET(err_code));
        return err_code;
    }
    /* Block TWI interrupts to ensure that function is not interrupted by TWI interrupt. */
    nrf_twim_int_disable(p_twim, NRF_TWIM_ALL_INTS_MASK);
    if (p_cb->busy)
    {
        nrf_twim_int_enable(p_twim, p_cb->int_mask);
        err_code = NRFX_ERROR_BUSY;
        NRFX_LOG_WARNING("Function: %s, error code: %s.",
                         __func__,
                         NRFX_LOG_ERROR_STRING_GET(err_code));
        return err_code;
    }
    else
    {
        p_cb->busy = ((NRFX_TWIM_FLAG_NO_XFER_EVT_HANDLER & flags) ||
                      (NRFX_TWIM_FLAG_REPEATED_XFER & flags)) ? false: true;
    }

    p_cb->xfer_desc = *p_xfer_desc;
    p_cb->repeated = (flags & NRFX_TWIM_FLAG_REPEATED_XFER) ? true : false;
    p_cb->flags = flags;
    nrf_twim_address_set(p_twim, p_xfer_desc->address);

    nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_STOPPED);
    nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_ERROR);
    nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_LASTTX);
    nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_SUSPENDED);

    twim_list_enable_handle(p_twim, flags);
    switch (p_xfer_desc->type)
    {
    case NRFX_TWIM_XFER_TXTX:
        NRFX_ASSERT(!(flags & NRFX_TWIM_FLAG_REPEATED_XFER));
        NRFX_ASSERT(!(flags & NRFX_TWIM_FLAG_HOLD_XFER));
        NRFX_ASSERT(!(flags & NRFX_TWIM_FLAG_NO_XFER_EVT_HANDLER));
        if (!nrfx_is_in_ram(p_xfer_desc->p_secondary_buf))
        {
            err_code = NRFX_ERROR_INVALID_ADDR;
            NRFX_LOG_WARNING("Function: %s, error code: %s.",
                             __func__,
                             NRFX_LOG_ERROR_STRING_GET(err_code));
            return err_code;
        }
        nrf_twim_shorts_set(p_twim, NRF_TWIM_SHORT_LASTTX_SUSPEND_MASK);
        nrf_twim_tx_buffer_set(p_twim, p_xfer_desc->p_primary_buf, p_xfer_desc->primary_length);
        nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_TXSTARTED);
        nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
        nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_STARTTX);
        while (!nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_TXSTARTED))
        {}
        NRFX_LOG_DEBUG("TWIM: Event: %s.", EVT_TO_STR_TWIM(NRF_TWIM_EVENT_TXSTARTED));
        nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_TXSTARTED);
        nrf_twim_tx_buffer_set(p_twim, p_xfer_desc->p_secondary_buf, p_xfer_desc->secondary_length);
        p_cb->int_mask = NRF_TWIM_INT_SUSPENDED_MASK;
        break;
    case NRFX_TWIM_XFER_TXRX:
        nrf_twim_tx_buffer_set(p_twim, p_xfer_desc->p_primary_buf, p_xfer_desc->primary_length);
        if (!nrfx_is_in_ram(p_xfer_desc->p_secondary_buf))
        {
            err_code = NRFX_ERROR_INVALID_ADDR;
            NRFX_LOG_WARNING("Function: %s, error code: %s.",
                             __func__,
                             NRFX_LOG_ERROR_STRING_GET(err_code));
            return err_code;
        }
        nrf_twim_rx_buffer_set(p_twim, p_xfer_desc->p_secondary_buf, p_xfer_desc->secondary_length);
        nrf_twim_shorts_set(p_twim, NRF_TWIM_SHORT_LASTTX_STARTRX_MASK |
                                    NRF_TWIM_SHORT_LASTRX_STOP_MASK);
        p_cb->int_mask = NRF_TWIM_INT_STOPPED_MASK;
        nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
        break;
    case NRFX_TWIM_XFER_TX:
        nrf_twim_tx_buffer_set(p_twim, p_xfer_desc->p_primary_buf, p_xfer_desc->primary_length);
        if (NRFX_TWIM_FLAG_TX_NO_STOP & flags)
        {
            nrf_twim_shorts_set(p_twim, NRF_TWIM_SHORT_LASTTX_SUSPEND_MASK);
            p_cb->int_mask = NRF_TWIM_INT_SUSPENDED_MASK;
        }
        else
        {
            nrf_twim_shorts_set(p_twim, NRF_TWIM_SHORT_LASTTX_STOP_MASK);
            p_cb->int_mask = NRF_TWIM_INT_STOPPED_MASK;
        }
        nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
        break;
    case NRFX_TWIM_XFER_RX:
        nrf_twim_rx_buffer_set(p_twim, p_xfer_desc->p_primary_buf, p_xfer_desc->primary_length);
        nrf_twim_shorts_set(p_twim, NRF_TWIM_SHORT_LASTRX_STOP_MASK);
        p_cb->int_mask = NRF_TWIM_INT_STOPPED_MASK;
        start_task = NRF_TWIM_TASK_STARTRX;
        nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
        break;
    default:
        err_code = NRFX_ERROR_INVALID_PARAM;
        break;
    }

    if (!(flags & NRFX_TWIM_FLAG_HOLD_XFER) && (p_xfer_desc->type != NRFX_TWIM_XFER_TXTX))
    {
        nrf_twim_task_trigger(p_twim, start_task);
    }

    if (p_cb->handler)
    {
        if (flags & NRFX_TWIM_FLAG_NO_XFER_EVT_HANDLER)
        {
            p_cb->int_mask = 0;
        }

        if (!(flags & NRFX_TWIM_FLAG_NO_SPURIOUS_STOP_CHECK))
        {
            p_cb->int_mask |= NRF_TWIM_INT_STOPPED_MASK;
        }

        // Interrupts for ERROR are implicitly enabled, regardless of driver configuration.
        p_cb->int_mask |= NRF_TWIM_INT_ERROR_MASK;
        nrf_twim_int_enable(p_twim, p_cb->int_mask);

#if NRFX_CHECK(NRFX_TWIM_NRF52_ANOMALY_109_WORKAROUND_ENABLED)
        if ((flags & NRFX_TWIM_FLAG_HOLD_XFER) && (p_xfer_desc->type != NRFX_TWIM_XFER_RX))
        {
            twim_list_enable_handle(p_twim, 0);
            p_twim->FREQUENCY = 0;
            nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_TXSTARTED);
            nrf_twim_int_enable(p_twim, NRF_TWIM_INT_TXSTARTED_MASK);
        } 
        else
        {
            nrf_twim_frequency_set(p_twim, p_cb->bus_frequency);
        }
#endif
    }
    else
    {
        bool transmission_finished = false;
        do {
            if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_SUSPENDED))
            {
                NRFX_LOG_DEBUG("TWIM: Event: %s.", EVT_TO_STR_TWIM(NRF_TWIM_EVENT_SUSPENDED));
                transmission_finished = true;
            }

            if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_STOPPED))
            {
                nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_STOPPED);
                NRFX_LOG_DEBUG("TWIM: Event: %s.", EVT_TO_STR_TWIM(NRF_TWIM_EVENT_STOPPED));
                transmission_finished = true;
            }

            if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_ERROR))
            {
                nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_ERROR);
                NRFX_LOG_DEBUG("TWIM: Event: %s.", EVT_TO_STR_TWIM(NRF_TWIM_EVENT_ERROR));

                bool lasttx_triggered = nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_LASTTX);
                uint32_t shorts_mask = nrf_twim_shorts_get(p_twim);

                if (!(lasttx_triggered && (shorts_mask & NRF_TWIM_SHORT_LASTTX_STOP_MASK)))
                {
                    // Unless LASTTX event arrived and LASTTX_STOP shortcut is active,
                    // triggering of STOP task in case of error has to be done manually.
                    nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
                    nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_STOP);

                    // Mark transmission as not finished yet,
                    // as STOPPED event is expected to arrive.
                    // If LASTTX_SUSPENDED shortcut is active,
                    // NACK has been received on last byte sent
                    // and SUSPENDED event happened to be checked before ERROR,
                    // transmission will be marked as finished.
                    // In such case this flag has to be overwritten.
                    transmission_finished = false;
                }

                if (lasttx_triggered && (shorts_mask & NRF_TWIM_SHORT_LASTTX_SUSPEND_MASK))
                {
                    // When STOP task was triggered just before SUSPEND task has taken effect,
                    // SUSPENDED event may not arrive.
                    // However if SUSPENDED arrives it always arrives after ERROR.
                    // Therefore SUSPENDED has to be cleared
                    // so it does not cause premature termination of busy loop
                    // waiting for STOPPED event to arrive.
                    nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_SUSPENDED);

                    // Mark transmission as not finished yet,
                    // for same reasons as above.
                    transmission_finished = false;
                }
            }
        } while (!transmission_finished);

        uint32_t errorsrc =  nrf_twim_errorsrc_get_and_clear(p_twim);

        p_cb->busy = false;

        if (errorsrc)
        {
            err_code = twi_process_error(errorsrc);
        }
        else
        {
            if (!(flags & NRFX_TWIM_FLAG_NO_SPURIOUS_STOP_CHECK) &&
                !xfer_completeness_check(p_twim, p_cb))
            {
                err_code = NRFX_ERROR_INTERNAL;
            }
        }
    }
    return err_code;
}


nrfx_err_t nrfx_twim_xfer(nrfx_twim_t           const * p_instance,
                          nrfx_twim_xfer_desc_t const * p_xfer_desc,
                          uint32_t                      flags)
{
    NRFX_ASSERT(TWIM_LENGTH_VALIDATE(p_instance->drv_inst_idx,
                                     p_xfer_desc->primary_length,
                                     p_xfer_desc->secondary_length));

    nrfx_err_t err_code = NRFX_SUCCESS;
    twim_control_block_t * p_cb = &m_cb[p_instance->drv_inst_idx];

    // TXRX and TXTX transfers are supported only in non-blocking mode.
    NRFX_ASSERT( !((p_cb->handler == NULL) && (p_xfer_desc->type == NRFX_TWIM_XFER_TXRX)));
    NRFX_ASSERT( !((p_cb->handler == NULL) && (p_xfer_desc->type == NRFX_TWIM_XFER_TXTX)));

    NRFX_LOG_INFO("Transfer type: %s.", TRANSFER_TO_STR(p_xfer_desc->type));
    NRFX_LOG_INFO("Transfer buffers length: primary: %d, secondary: %d.",
                  p_xfer_desc->primary_length,
                  p_xfer_desc->secondary_length);
    NRFX_LOG_DEBUG("Primary buffer data:");
    NRFX_LOG_HEXDUMP_DEBUG(p_xfer_desc->p_primary_buf,
                           p_xfer_desc->primary_length * sizeof(p_xfer_desc->p_primary_buf[0]));
    NRFX_LOG_DEBUG("Secondary buffer data:");
    NRFX_LOG_HEXDUMP_DEBUG(p_xfer_desc->p_secondary_buf,
                           p_xfer_desc->secondary_length * sizeof(p_xfer_desc->p_secondary_buf[0]));

    err_code = twim_xfer(p_cb, (NRF_TWIM_Type *)p_instance->p_twim, p_xfer_desc, flags);
    NRFX_LOG_WARNING("Function: %s, error code: %s.",
                     __func__,
                     NRFX_LOG_ERROR_STRING_GET(err_code));
    return err_code;
}

uint32_t nrfx_twim_start_task_get(nrfx_twim_t const * p_instance,
                                  nrfx_twim_xfer_type_t xfer_type)
{
    return nrf_twim_task_address_get(p_instance->p_twim,
        (xfer_type != NRFX_TWIM_XFER_RX) ? NRF_TWIM_TASK_STARTTX : NRF_TWIM_TASK_STARTRX);
}

uint32_t nrfx_twim_stopped_event_get(nrfx_twim_t const * p_instance)
{
    return nrf_twim_event_address_get(p_instance->p_twim, NRF_TWIM_EVENT_STOPPED);
}

static void twim_irq_handler(NRF_TWIM_Type * p_twim, twim_control_block_t * p_cb)
{

#if NRFX_CHECK(NRFX_TWIM_NRF52_ANOMALY_109_WORKAROUND_ENABLED)
    /* Handle only workaround case. Can be used without TWIM handler in IRQs. */
    if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_TXSTARTED))
    {
        nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_TXSTARTED);
        nrf_twim_int_disable(p_twim, NRF_TWIM_INT_TXSTARTED_MASK);
        if (p_twim->FREQUENCY == 0)
        {
            // Set enable to zero to reset TWIM internal state.
            nrf_twim_disable(p_twim);
            nrf_twim_enable(p_twim);

            // Set proper frequency.
            nrf_twim_frequency_set(p_twim, p_cb->bus_frequency);
            twim_list_enable_handle(p_twim, p_cb->flags);

            // Start proper transmission.
            nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_STARTTX);
            return;
        }
    }
#endif

    NRFX_ASSERT(p_cb->handler);

    if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_ERROR))
    {
        nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_ERROR);
        NRFX_LOG_DEBUG("TWIM: Event: %s.", EVT_TO_STR_TWIM(NRF_TWIM_EVENT_ERROR));
        if (!nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_STOPPED))
        {
            nrf_twim_int_disable(p_twim, p_cb->int_mask);
            p_cb->int_mask = NRF_TWIM_INT_STOPPED_MASK;
            nrf_twim_int_enable(p_twim, p_cb->int_mask);

            if (!(nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_LASTTX) &&
                 (nrf_twim_shorts_get(p_twim) & NRF_TWIM_SHORT_LASTTX_STOP_MASK)))
            {
                nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
                nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_STOP);
            }

            p_cb->error = true;
            return;
        }
    }

    nrfx_twim_evt_t event;

    if (nrf_twim_event_check(p_twim, NRF_TWIM_EVENT_STOPPED))
    {
        NRFX_LOG_DEBUG("TWIM: Event: %s.", EVT_TO_STR_TWIM(NRF_TWIM_EVENT_STOPPED));
        nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_STOPPED);

        if (!(p_cb->flags & NRFX_TWIM_FLAG_NO_SPURIOUS_STOP_CHECK) && !p_cb->error)
        {
            p_cb->error = !xfer_completeness_check(p_twim, p_cb);
        }

        // Further processing of STOPPED event is valid only if NO_XFER_EVT_HANDLER
        // setting is not used.
        if (!(p_cb->flags & NRFX_TWIM_FLAG_NO_XFER_EVT_HANDLER))
        {
            event.xfer_desc = p_cb->xfer_desc;
            nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_LASTTX);
            nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_LASTRX);
            if (!p_cb->repeated || p_cb->error)
            {
                nrf_twim_shorts_set(p_twim, 0);
                p_cb->int_mask = 0;
                nrf_twim_int_disable(p_twim, NRF_TWIM_ALL_INTS_MASK);

                // At this point interrupt handler should not be invoked again for current transfer.
                // If STOPPED arrived during ERROR processing,
                // its pending interrupt should be ignored.
                // Otherwise spurious NRFX_TWIM_EVT_DONE or NRFX_TWIM_EVT_BUS_ERROR
                // would be passed to user's handler.
                NRFX_IRQ_PENDING_CLEAR(nrfx_get_irq_number(p_twim));
            }
        }

#if NRFX_CHECK(NRFX_TWIM_NRF52_ANOMALY_109_WORKAROUND_ENABLED)
        else if (p_cb->xfer_desc.type != NRFX_TWIM_XFER_RX)
        {
            /* Add Anomaly 109 workaround for each potential repeated transfer starting from TX. */
            twim_list_enable_handle(p_twim, 0);
            p_twim->FREQUENCY = 0;
            nrf_twim_int_enable(p_twim, NRF_TWIM_INT_TXSTARTED_MASK);
        }
#endif
    }
    else
    {
        nrf_twim_event_clear(p_twim, NRF_TWIM_EVENT_SUSPENDED);
        NRFX_LOG_DEBUG("TWIM: Event: %s.", EVT_TO_STR_TWIM(NRF_TWIM_EVENT_SUSPENDED));
        if (p_cb->xfer_desc.type == NRFX_TWIM_XFER_TX)
        {
            event.xfer_desc = p_cb->xfer_desc;
            if (!p_cb->repeated)
            {
                nrf_twim_shorts_set(p_twim, 0);
                p_cb->int_mask = 0;
                nrf_twim_int_disable(p_twim, NRF_TWIM_ALL_INTS_MASK);

                // At this point interrupt handler should not be invoked again for current transfer.
                // If STOPPED arrived during SUSPENDED processing,
                // its pending interrupt should be ignored.
                // Otherwise spurious NRFX_TWIM_EVT_DONE or NRFX_TWIM_EVT_BUS_ERROR
                // would be passed to user's handler.
                NRFX_IRQ_PENDING_CLEAR(nrfx_get_irq_number(p_twim));
            }
        }
        else
        {
            nrf_twim_shorts_set(p_twim, NRF_TWIM_SHORT_LASTTX_STOP_MASK);
            p_cb->int_mask = NRF_TWIM_INT_STOPPED_MASK | NRF_TWIM_INT_ERROR_MASK;
            nrf_twim_int_disable(p_twim, NRF_TWIM_ALL_INTS_MASK);
            nrf_twim_int_enable(p_twim, p_cb->int_mask);
            nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_STARTTX);
            nrf_twim_task_trigger(p_twim, NRF_TWIM_TASK_RESUME);
            return;
        }
    }

    uint32_t errorsrc = nrf_twim_errorsrc_get_and_clear(p_twim);
    if (errorsrc & NRF_TWIM_ERROR_ADDRESS_NACK)
    {
        event.type = NRFX_TWIM_EVT_ADDRESS_NACK;
        NRFX_LOG_DEBUG("Event: %s.", EVT_TO_STR(NRFX_TWIM_EVT_ADDRESS_NACK));
    }
    else if (errorsrc & NRF_TWIM_ERROR_DATA_NACK)
    {
        event.type = NRFX_TWIM_EVT_DATA_NACK;
        NRFX_LOG_DEBUG("Event: %s.", EVT_TO_STR(NRFX_TWIM_EVT_DATA_NACK));
    }
    else if (errorsrc & NRF_TWIM_ERROR_OVERRUN)
    {
        event.type = NRFX_TWIM_EVT_OVERRUN;
        NRFX_LOG_DEBUG("Event: %s.", EVT_TO_STR(NRFX_TWIM_EVT_OVERRUN));
    }
    else if (p_cb->error)
    {
        event.type = NRFX_TWIM_EVT_BUS_ERROR;
        NRFX_LOG_DEBUG("Event: %s.", EVT_TO_STR(NRFX_TWIM_EVT_BUS_ERROR));
    }
    else
    {
        event.type = NRFX_TWIM_EVT_DONE;
        NRFX_LOG_DEBUG("Event: %s.", EVT_TO_STR(NRFX_TWIM_EVT_DONE));
    }

    if (!p_cb->repeated)
    {
        p_cb->busy = false;
    }

    if (!(p_cb->flags & NRFX_TWIM_FLAG_NO_XFER_EVT_HANDLER) || p_cb->error)
    {
        p_cb->handler(&event, p_cb->p_context);
    }
}

#if NRFX_CHECK(NRFX_TWIM0_ENABLED)
void nrfx_twim_0_irq_handler(void)
{
    twim_irq_handler(NRF_TWIM0, &m_cb[NRFX_TWIM0_INST_IDX]);
}
#endif

#if NRFX_CHECK(NRFX_TWIM1_ENABLED)
void nrfx_twim_1_irq_handler(void)
{
    twim_irq_handler(NRF_TWIM1, &m_cb[NRFX_TWIM1_INST_IDX]);
}
#endif

#if NRFX_CHECK(NRFX_TWIM2_ENABLED)
void nrfx_twim_2_irq_handler(void)
{
    twim_irq_handler(NRF_TWIM2, &m_cb[NRFX_TWIM2_INST_IDX]);
}
#endif

#if NRFX_CHECK(NRFX_TWIM3_ENABLED)
void nrfx_twim_3_irq_handler(void)
{
    twim_irq_handler(NRF_TWIM3, &m_cb[NRFX_TWIM3_INST_IDX]);
}
#endif

#endif // NRFX_CHECK(NRFX_TWIM_ENABLED)
