text: /**
   * Copyright (c) 2016 - 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.
   * 
   * 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.
   * 
   */
  
  #include "nrf_serial_flash_params.h"
  #include "nrf_block_dev_qspi.h"
  
  /**@file
   *
   * @ingroup nrf_block_dev_qspi
   * @{
   *
   * @brief This module implements block device API. It should be used as a reference block device.
   */
  
  #define QSPI_STD_CMD_WRSR    0x01   /**< Write status register command*/
  #define QSPI_STD_CMD_RSTEN   0x66   /**< Reset enable command*/
  #define QSPI_STD_CMD_RST     0x99   /**< Reset command*/
  #define QSPI_STD_CMD_READ_ID 0x9F   /**< Read ID command*/
  
  #define BD_PAGE_PROGRAM_SIZE 256    /**< Page program size (minimum block size)*/
  
  #define BD_ERASE_UNIT_INVALID_ID   0xFFFFFFFF /**< Invalid erase unit number*/
  #define BD_ERASE_UNIT_ERASE_VAL    0xFFFFFFFF /**< Erased memory value*/
  
  /**
   * @brief Block to erase unit translation
   *
   * @param blk_id    Block index
   * @param blk_size  Block size
   * */
  #define BD_BLOCK_TO_ERASEUNIT(blk_id, blk_size)   \
      ((blk_id) * (blk_size)) / (NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE)
  
  /**
   * @brief Blocks per erase unit
   *
   * @param blk_size  Block size
   * */
  #define BD_BLOCKS_PER_ERASEUNIT(blk_size)         \
      (NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE / (blk_size))
  
  
  static ret_code_t block_dev_qspi_eunit_write(nrf_block_dev_qspi_t const * p_qspi_dev,
                                               nrf_block_req_t * p_blk_left);
  
  
  static void block_dev_qspi_read_from_eunit(nrf_block_dev_qspi_t const * p_qspi_dev)
  {
      nrf_block_dev_qspi_work_t const * p_work = p_qspi_dev->p_work;
  
      /*In write-back mode data that we read might not be the same as in erase unit buffer*/
      uint32_t eunit_start = BD_BLOCK_TO_ERASEUNIT(p_work->req.blk_id,
                                                   p_work->geometry.blk_size);
  
      uint32_t eunit_end = BD_BLOCK_TO_ERASEUNIT(p_work->req.blk_id + p_work->req.blk_count,
                                                 p_work->geometry.blk_size);
  
      if ((eunit_start > p_work->erase_unit_idx) || (eunit_end < p_work->erase_unit_idx))
      {
          /*Do nothing. Read request doesn't hit current cached erase unit*/
          return;
      }
  
      /*Case 1: Copy data from start erase unit*/
      if (eunit_start == p_work->erase_unit_idx)
      {
           size_t blk = p_work->req.blk_id %
                        BD_BLOCKS_PER_ERASEUNIT(p_work->geometry.blk_size);
           size_t cnt = BD_BLOCKS_PER_ERASEUNIT(p_work->geometry.blk_size) - blk;
           size_t off = p_work->geometry.blk_size * blk;
  
           if (cnt > p_work->req.blk_count)
           {
               cnt = p_work->req.blk_count;
           }
  
           memcpy(p_work->req.p_buff,
                  p_work->p_erase_unit_buff + off,
                  cnt * p_work->geometry.blk_size);
  
           return;
      }
  
      /*Case 2: Copy data from end erase unit*/
      if (eunit_end == p_work->erase_unit_idx)
      {
           size_t cnt = (p_work->req.blk_id + p_work->req.blk_count) %
                         BD_BLOCKS_PER_ERASEUNIT(p_work->geometry.blk_size);
           size_t off = (p_work->erase_unit_idx * BD_BLOCKS_PER_ERASEUNIT(p_work->geometry.blk_size) -
                         p_work->req.blk_id) * p_work->geometry.blk_size;
  
           if (cnt > p_work->req.blk_count)
           {
               cnt = p_work->req.blk_count;
           }
  
           memcpy((uint8_t *)p_work->req.p_buff + off,
                  p_work->p_erase_unit_buff,
                  cnt * p_work->geometry.blk_size);
  
           return;
      }
  
      /*Case 3: Copy data from  eunit_start < p_work->erase_unit_idx < eunit_end*/
      size_t off = (p_work->erase_unit_idx * BD_BLOCKS_PER_ERASEUNIT(p_work->geometry.blk_size) -
                    p_work->req.blk_id) * p_work->geometry.blk_size;
  
      memcpy((uint8_t *)p_work->req.p_buff + off,
             p_work->p_erase_unit_buff,
             NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE);
  }
  
  /**
   * @brief Active QSPI block device handle. Only one instance.
   * */
  static nrf_block_dev_qspi_t const * m_active_qspi_dev;
  
  static void qspi_handler(nrf_drv_qspi_evt_t event, void * p_context)
  {
      if (m_active_qspi_dev != p_context)
      {
          return;
      }
  
      nrf_block_dev_qspi_t const * p_qspi_dev = p_context;
      nrf_block_dev_qspi_work_t *  p_work = p_qspi_dev->p_work;
      nrf_block_req_t * p_blk_left = &p_work->left_req;
  
      switch (p_work->state)
      {
          case NRF_BLOCK_DEV_QSPI_STATE_READ_EXEC:
          {
              if (p_work->writeback_mode)
              {
                  block_dev_qspi_read_from_eunit(p_qspi_dev);
              }
  
              p_work->state = NRF_BLOCK_DEV_QSPI_STATE_IDLE;
              if (p_work->ev_handler)
              {
                  const nrf_block_dev_event_t ev = {
                          NRF_BLOCK_DEV_EVT_BLK_READ_DONE,
                          NRF_BLOCK_DEV_RESULT_SUCCESS,
                          &p_work->req,
                          p_work->p_context
                  };
  
                  p_work->ev_handler(&p_qspi_dev->block_dev, &ev);
              }
  
              break;
          }
          case NRF_BLOCK_DEV_QSPI_STATE_EUNIT_LOAD:
          {
              ret_code_t ret;
              uint32_t erase_unit = BD_BLOCK_TO_ERASEUNIT(p_blk_left->blk_id,
                                                          p_work->geometry.blk_size);
              UNUSED_VARIABLE(erase_unit);
              ASSERT(erase_unit == p_work->erase_unit_idx);
  
              /* Check if block is in erase unit buffer*/
              ret = block_dev_qspi_eunit_write(p_qspi_dev, p_blk_left);
              ASSERT(ret == NRF_SUCCESS);
              UNUSED_VARIABLE(ret);
              break;
          }
          case NRF_BLOCK_DEV_QSPI_STATE_WRITE_ERASE:
          case NRF_BLOCK_DEV_QSPI_STATE_WRITE_EXEC:
          {
              /*Clear last programmed block*/
              uint32_t block_to_program = __CLZ(__RBIT(p_work->erase_unit_dirty_blocks));
  
              if (p_work->state == NRF_BLOCK_DEV_QSPI_STATE_WRITE_EXEC)
              {
                  p_work->erase_unit_dirty_blocks ^= 1u << block_to_program;
              }
  
              if (p_work->erase_unit_dirty_blocks == 0)
              {
                  if (p_work->left_req.blk_count)
                  {
                      /*Load next erase unit*/
                      ret_code_t ret;
                      uint32_t eunit = BD_BLOCK_TO_ERASEUNIT(p_blk_left->blk_id,
                                                             p_work->geometry.blk_size);
  
                      p_work->erase_unit_idx = eunit;
                      p_work->state = NRF_BLOCK_DEV_QSPI_STATE_EUNIT_LOAD;
  
                      ret = nrf_drv_qspi_read(p_work->p_erase_unit_buff,
                                              NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE,
                                              p_work->erase_unit_idx *
                                              NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE);
                      UNUSED_VARIABLE(ret);
  
                      break;
                  }
  
                  /*All blocks are programmed. Call event handler if required.*/
                  p_work->state = NRF_BLOCK_DEV_QSPI_STATE_IDLE;
                  if (p_work->ev_handler && !p_work->cache_flushing)
                  {
                      const nrf_block_dev_event_t ev = {
                              NRF_BLOCK_DEV_EVT_BLK_WRITE_DONE,
                              NRF_BLOCK_DEV_RESULT_SUCCESS,
                              &p_work->req,
                              p_work->p_context
                      };
  
                      p_work->ev_handler(&p_qspi_dev->block_dev, &ev);
                  }
  
                  p_work->cache_flushing = false;
                  break;
              }
  
              /*Get next block to program from program mask*/
              block_to_program = __CLZ(__RBIT(p_work->erase_unit_dirty_blocks));
              uint32_t dst_address = (p_work->erase_unit_idx * NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE) +
                                     (block_to_program * p_work->geometry.blk_size);
  
              const void * p_src_address = p_work->p_erase_unit_buff +
                                           block_to_program * p_work->geometry.blk_size;
  
              p_work->state = NRF_BLOCK_DEV_QSPI_STATE_WRITE_EXEC;
              ret_code_t ret = nrf_drv_qspi_write(p_src_address,
                                                  p_work->geometry.blk_size,
                                                  dst_address);
              UNUSED_VARIABLE(ret);
              break;
          }
          default:
              ASSERT(0);
              break;
      }
  }
  
  static void wait_for_idle(nrf_block_dev_qspi_t const * p_qspi_dev)
  {
      nrf_block_dev_qspi_work_t * p_work = p_qspi_dev->p_work;
      while (p_work->state != NRF_BLOCK_DEV_QSPI_STATE_IDLE)
      {
          __WFI();
      }
  }
  
  static ret_code_t block_dev_qspi_init(nrf_block_dev_t const * p_blk_dev,
                                        nrf_block_dev_ev_handler ev_handler,
                                        void const * p_context)
  {
      ASSERT(p_blk_dev);
      nrf_block_dev_qspi_t const *  p_qspi_dev =
                                    CONTAINER_OF(p_blk_dev, nrf_block_dev_qspi_t, block_dev);
      nrf_block_dev_qspi_work_t *   p_work = p_qspi_dev->p_work;
      nrf_drv_qspi_config_t const * p_qspi_cfg = &p_qspi_dev->qspi_bdev_config.qspi_config;
  
      ret_code_t ret = NRF_SUCCESS;
  
      if (p_qspi_dev->qspi_bdev_config.block_size % BD_PAGE_PROGRAM_SIZE)
      {
          /*Unsupported block size*/
          return NRF_ERROR_NOT_SUPPORTED;
      }
  
      if (NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE % p_qspi_dev->qspi_bdev_config.block_size)
      {
          /*Unsupported block size*/
          return NRF_ERROR_NOT_SUPPORTED;
      }
  
      if (m_active_qspi_dev)
      {
          /* QSPI instance is BUSY*/
          return NRF_ERROR_BUSY;
      }
  
      ret = nrf_drv_qspi_init(p_qspi_cfg, qspi_handler, (void *)p_blk_dev);
      if (ret != NRF_SUCCESS)
      {
          return ret;
      }
  
      nrf_qspi_cinstr_conf_t cinstr_cfg = {
          .opcode    = QSPI_STD_CMD_RSTEN,
          .length    = NRF_QSPI_CINSTR_LEN_1B,
          .io2_level = true,
          .io3_level = true,
          .wipwait   = true,
          .wren      = true
      };
  
      /* Send reset enable */
      ret = nrf_drv_qspi_cinstr_xfer(&cinstr_cfg, NULL, NULL);
      if (ret != NRF_SUCCESS)
      {
          return ret;
      }
  
      /* Send reset command */
      cinstr_cfg.opcode = QSPI_STD_CMD_RST;
      ret = nrf_drv_qspi_cinstr_xfer(&cinstr_cfg, NULL, NULL);
      if (ret != NRF_SUCCESS)
      {
          return ret;
      }
  
      /* Get 3 byte identification value */
      uint8_t rdid_buf[3] = {0, 0, 0};
      cinstr_cfg.opcode = QSPI_STD_CMD_READ_ID;
      cinstr_cfg.length = NRF_QSPI_CINSTR_LEN_4B;
      ret = nrf_drv_qspi_cinstr_xfer(&cinstr_cfg, NULL, rdid_buf);
      if (ret != NRF_SUCCESS)
      {
          return ret;
      }
  
      nrf_serial_flash_params_t const * serial_flash_id = nrf_serial_flash_params_get(rdid_buf);
  
      if (!serial_flash_id)
      {
          return NRF_ERROR_NOT_SUPPORTED;
      }
  
      if (serial_flash_id->erase_size != NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE)
      {
          return NRF_ERROR_NOT_SUPPORTED;
      }
  
      /* Calculate block device geometry.... */
      uint32_t blk_size = p_qspi_dev->qspi_bdev_config.block_size;
      uint32_t blk_count = serial_flash_id->size / p_qspi_dev->qspi_bdev_config.block_size;
  
      if (!blk_count || (blk_count % BD_BLOCKS_PER_ERASEUNIT(blk_size)))
      {
          return NRF_ERROR_NOT_SUPPORTED;
      }
  
      p_work->geometry.blk_size = blk_size;
      p_work->geometry.blk_count = blk_count;
      p_work->p_context = p_context;
      p_work->ev_handler = ev_handler;
  
      p_work->state = NRF_BLOCK_DEV_QSPI_STATE_IDLE;
      p_work->erase_unit_idx = BD_ERASE_UNIT_INVALID_ID;
      p_work->writeback_mode =  (p_qspi_dev->qspi_bdev_config.flags &
                                 NRF_BLOCK_DEV_QSPI_FLAG_CACHE_WRITEBACK) != 0;
      m_active_qspi_dev = p_qspi_dev;
  
      if (p_work->ev_handler)
      {
          /*Asynchronous operation (simulation)*/
          const nrf_block_dev_event_t ev = {
                  NRF_BLOCK_DEV_EVT_INIT,
                  NRF_BLOCK_DEV_RESULT_SUCCESS,
                  NULL,
                  p_work->p_context
          };
  
          p_work->ev_handler(p_blk_dev, &ev);
      }
  
      return NRF_SUCCESS;
  }
  
  static ret_code_t block_dev_qspi_uninit(nrf_block_dev_t const * p_blk_dev)
  {
      ASSERT(p_blk_dev);
      nrf_block_dev_qspi_t const * p_qspi_dev =
                                   CONTAINER_OF(p_blk_dev, nrf_block_dev_qspi_t, block_dev);
      nrf_block_dev_qspi_work_t * p_work = p_qspi_dev->p_work;
  
      if (m_active_qspi_dev != p_qspi_dev)
      {
          /* QSPI instance is BUSY*/
          return NRF_ERROR_BUSY;
      }
  
      if (p_work->state != NRF_BLOCK_DEV_QSPI_STATE_IDLE)
      {
          /* Previous asynchronous operation in progress*/
          return NRF_ERROR_BUSY;
      }
  
      if (p_work->ev_handler)
      {
          /*Asynchronous operation*/
          const nrf_block_dev_event_t ev = {
                  NRF_BLOCK_DEV_EVT_UNINIT,
                  NRF_BLOCK_DEV_RESULT_SUCCESS,
                  NULL,
                  p_work->p_context
          };
  
          p_work->ev_handler(p_blk_dev, &ev);
      }
  
      p_work->state = NRF_BLOCK_DEV_QSPI_STATE_DISABLED;
      nrf_drv_qspi_uninit();
  
      memset(p_work, 0, sizeof(nrf_block_dev_qspi_work_t));
      m_active_qspi_dev = NULL;
      return NRF_SUCCESS;
  }
  
  static ret_code_t block_dev_qspi_read_req(nrf_block_dev_t const * p_blk_dev,
                                            nrf_block_req_t const * p_blk)
  {
      ASSERT(p_blk_dev);
      ASSERT(p_blk);
      nrf_block_dev_qspi_t const * p_qspi_dev =
                                   CONTAINER_OF(p_blk_dev, nrf_block_dev_qspi_t, block_dev);
      nrf_block_dev_qspi_work_t *  p_work = p_qspi_dev->p_work;
  
      ret_code_t ret = NRF_SUCCESS;
  
      if (m_active_qspi_dev != p_qspi_dev)
      {
          /* QSPI instance is BUSY*/
          return NRF_ERROR_BUSY;
      }
  
      if (p_work->state != NRF_BLOCK_DEV_QSPI_STATE_IDLE)
      {
          /* Previous asynchronous operation in progress*/
          return NRF_ERROR_BUSY;
      }
  
      p_work->left_req = *p_blk;
      p_work->req = *p_blk;
      nrf_block_req_t * p_blk_left = &p_work->left_req;
  
      p_work->state = NRF_BLOCK_DEV_QSPI_STATE_READ_EXEC;
      ret = nrf_drv_qspi_read(p_blk_left->p_buff,
                              p_blk_left->blk_count * p_work->geometry.blk_size,
                              p_blk_left->blk_id * p_work->geometry.blk_size);
  
      if (ret != NRF_SUCCESS)
      {
          p_work->state = NRF_BLOCK_DEV_QSPI_STATE_IDLE;
          return ret;
      }
  
      p_blk_left->p_buff = NULL;
      p_blk_left->blk_count = 0;
  
      if (!p_work->ev_handler && (p_work->state != NRF_BLOCK_DEV_QSPI_STATE_IDLE))
      {
          /*Synchronous operation*/
          wait_for_idle(p_qspi_dev);
      }
  
      return ret;
  }
  
  static bool block_dev_qspi_update_eunit(nrf_block_dev_qspi_t const * p_qspi_dev,
                                          size_t off,
                                          const void * p_src,
                                          size_t len)
  {
      ASSERT((len % sizeof(uint32_t)) == 0)
      nrf_block_dev_qspi_work_t *  p_work = p_qspi_dev->p_work;
  
      uint32_t *       p_dst32 = (uint32_t *)(p_work->p_erase_unit_buff + off);
      const uint32_t * p_src32 = p_src;
  
      bool erase_required = false;
      len /= sizeof(uint32_t);
  
      /*Do normal copying until erase unit is not required*/
      do
      {
          if (*p_dst32 != *p_src32)
          {
              if (*p_dst32 != BD_ERASE_UNIT_ERASE_VAL)
              {
                  erase_required = true;
              }
  
              /*Mark block as dirty*/
              p_work->erase_unit_dirty_blocks |= 1u << (off / p_work->geometry.blk_size);
          }
  
          *p_dst32++ = *p_src32++;
          off += sizeof(uint32_t);
      } while (--len);
  
      return erase_required;
  }
  
  static ret_code_t block_dev_qspi_write_start(nrf_block_dev_qspi_t const * p_qspi_dev)
  {
      nrf_block_dev_qspi_work_t *  p_work = p_qspi_dev->p_work;
  
      if (!p_work->erase_required)
      {
          /*Get first block to program from program mask*/
          uint32_t block_to_program = __CLZ(__RBIT(p_work->erase_unit_dirty_blocks));
          uint32_t dst_address = (p_work->erase_unit_idx * NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE) +
                                 (block_to_program * p_work->geometry.blk_size);
  
          const void * p_src_address = p_work->p_erase_unit_buff +
                                       block_to_program * p_work->geometry.blk_size;
  
          p_work->state = NRF_BLOCK_DEV_QSPI_STATE_WRITE_EXEC;
          return nrf_drv_qspi_write(p_src_address,
                                    p_work->geometry.blk_size,
                                    dst_address);
      }
  
      /*Erase is required*/
      uint32_t address = (p_work->erase_unit_idx * NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE);
      p_work->state = NRF_BLOCK_DEV_QSPI_STATE_WRITE_ERASE;
      p_work->erase_required = false;
  
      return nrf_drv_qspi_erase(NRF_QSPI_ERASE_LEN_4KB, address);
  }
  
  static ret_code_t block_dev_qspi_eunit_write(nrf_block_dev_qspi_t const * p_qspi_dev,
                                               nrf_block_req_t * p_blk_left)
  {
      nrf_block_dev_qspi_work_t *  p_work = p_qspi_dev->p_work;
  
      size_t blk = p_blk_left->blk_id %
                   BD_BLOCKS_PER_ERASEUNIT(p_work->geometry.blk_size);
      size_t cnt = BD_BLOCKS_PER_ERASEUNIT(p_work->geometry.blk_size) - blk;
      size_t off = p_work->geometry.blk_size * blk;
  
      if (cnt > p_blk_left->blk_count)
      {
          cnt = p_blk_left->blk_count;
      }
  
      bool erase_required = block_dev_qspi_update_eunit(p_qspi_dev,
                                                        off,
                                                        p_blk_left->p_buff,
                                                        cnt * p_work->geometry.blk_size);
      if (erase_required)
      {
          p_work->erase_required = true;
      }
  
      p_blk_left->blk_count -= cnt;
      p_blk_left->blk_id += cnt;
      p_blk_left->p_buff = (uint8_t *)p_blk_left->p_buff + cnt * p_work->geometry.blk_size;
  
      if (p_work->erase_required)
      {
          uint32_t blk_size = p_work->geometry.blk_size;
          p_work->erase_unit_dirty_blocks |= (1u << BD_BLOCKS_PER_ERASEUNIT(blk_size)) - 1;
      }
  
      if (p_work->erase_unit_dirty_blocks == 0 || p_work->writeback_mode)
      {
          /*No dirty blocks detected. Write end.*/
          if (p_work->ev_handler && p_blk_left->blk_count == 0)
          {
              const nrf_block_dev_event_t ev = {
                      NRF_BLOCK_DEV_EVT_BLK_WRITE_DONE,
                      NRF_BLOCK_DEV_RESULT_SUCCESS,
                      &p_work->req,
                      p_work->p_context
              };
  
  
              p_work->state = NRF_BLOCK_DEV_QSPI_STATE_IDLE;
              p_work->ev_handler(&p_qspi_dev->block_dev, &ev);
              return NRF_SUCCESS;
          }
      }
  
      return block_dev_qspi_write_start(p_qspi_dev);
  }
  
  static ret_code_t block_dev_qspi_write_req(nrf_block_dev_t const * p_blk_dev,
                                             nrf_block_req_t const * p_blk)
  {
      ASSERT(p_blk_dev);
      ASSERT(p_blk);
      nrf_block_dev_qspi_t const * p_qspi_dev =
                                   CONTAINER_OF(p_blk_dev, nrf_block_dev_qspi_t, block_dev);
      nrf_block_dev_qspi_work_t *  p_work = p_qspi_dev->p_work;
  
      ret_code_t ret = NRF_SUCCESS;
  
      if (m_active_qspi_dev != p_qspi_dev)
      {
          /* QSPI instance is BUSY*/
          return NRF_ERROR_BUSY;
      }
  
      if (p_work->state != NRF_BLOCK_DEV_QSPI_STATE_IDLE)
      {
          /* Previous asynchronous operation in progress*/
          return NRF_ERROR_BUSY;
      }
  
      p_work->left_req = *p_blk;
      p_work->req = *p_blk;
  
      nrf_block_req_t * p_blk_left = &p_work->left_req;
  
      uint32_t erase_unit = BD_BLOCK_TO_ERASEUNIT(p_blk_left->blk_id,
                                                  p_work->geometry.blk_size);
  
      /* Check if block is in erase unit buffer*/
      if (erase_unit == p_work->erase_unit_idx)
      {
          ret = block_dev_qspi_eunit_write(p_qspi_dev, p_blk_left);
      }
      else
      {
          if (p_work->writeback_mode)
          {
              ret = block_dev_qspi_write_start(p_qspi_dev);
          }
          else
          {
              p_work->erase_unit_idx = erase_unit;
              p_work->state = NRF_BLOCK_DEV_QSPI_STATE_EUNIT_LOAD;
  
              ret = nrf_drv_qspi_read(p_work->p_erase_unit_buff,
                      NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE,
                      erase_unit * NRF_BLOCK_DEV_QSPI_ERASE_UNIT_SIZE);
          }
      }
  
      if (ret != NRF_SUCCESS)
      {
          p_work->state = NRF_BLOCK_DEV_QSPI_STATE_IDLE;
          return ret;
      }
  
      if (!p_work->ev_handler && (p_work->state != NRF_BLOCK_DEV_QSPI_STATE_IDLE))
      {
          /*Synchronous operation*/
          wait_for_idle(p_qspi_dev);
      }
  
      return ret;
  }
  
  static ret_code_t block_dev_qspi_ioctl(nrf_block_dev_t const * p_blk_dev,
                                         nrf_block_dev_ioctl_req_t req,
                                         void * p_data)
  {
      ASSERT(p_blk_dev);
      nrf_block_dev_qspi_t const * p_qspi_dev =
                                   CONTAINER_OF(p_blk_dev, nrf_block_dev_qspi_t, block_dev);
      nrf_block_dev_qspi_work_t *  p_work = p_qspi_dev->p_work;
  
      switch (req)
      {
          case NRF_BLOCK_DEV_IOCTL_REQ_CACHE_FLUSH:
          {
              bool * p_flushing = p_data;
              if (p_work->state != NRF_BLOCK_DEV_QSPI_STATE_IDLE)
              {
                  return NRF_ERROR_BUSY;
              }
  
              if (!p_work->writeback_mode || p_work->erase_unit_dirty_blocks == 0)
              {
                  if (p_flushing)
                  {
                      *p_flushing = false;
                  }
  
                  return NRF_SUCCESS;
              }
  
              ret_code_t ret =  block_dev_qspi_write_start(p_qspi_dev);
              if (ret == NRF_SUCCESS)
              {
                  if (p_flushing)
                  {
                      *p_flushing = true;
                  }
                  p_work->cache_flushing = true;
              }
  
              return ret;
          }
          case NRF_BLOCK_DEV_IOCTL_REQ_INFO_STRINGS:
          {
              if (p_data == NULL)
              {
                  return NRF_ERROR_INVALID_PARAM;
              }
  
              nrf_block_dev_info_strings_t const * * pp_strings = p_data;
              *pp_strings = &p_qspi_dev->info_strings;
              return NRF_SUCCESS;
          }
          default:
              break;
      }
  
      return NRF_ERROR_NOT_SUPPORTED;
  }
  
  static nrf_block_dev_geometry_t const * block_dev_qspi_geometry(nrf_block_dev_t const * p_blk_dev)
  {
      ASSERT(p_blk_dev);
      nrf_block_dev_qspi_t const * p_qspi_dev =
                                   CONTAINER_OF(p_blk_dev, nrf_block_dev_qspi_t, block_dev);
      nrf_block_dev_qspi_work_t const * p_work = p_qspi_dev->p_work;
  
      return &p_work->geometry;
  }
  
  const nrf_block_dev_ops_t nrf_block_device_qspi_ops = {
          .init = block_dev_qspi_init,
          .uninit = block_dev_qspi_uninit,
          .read_req = block_dev_qspi_read_req,
          .write_req = block_dev_qspi_write_req,
          .ioctl = block_dev_qspi_ioctl,
          .geometry = block_dev_qspi_geometry,
  };
  
  
  /** @} */
  