path: root/os/hal/src/mmc_spi.c

/*
    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/
/*
   Parts of this file have been contributed by Matthias Blaicher.
 */

/**
 * @file    mmc_spi.c
 * @brief   MMC over SPI driver code.
 *
 * @addtogroup MMC_SPI
 * @{
 */

#include <string.h>

#include "hal.h"

#if (HAL_USE_MMC_SPI == TRUE) || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

/* Forward declarations required by mmc_vmt.*/
static bool mmc_read(void *instance, uint32_t startblk,
                       uint8_t *buffer, uint32_t n);
static bool mmc_write(void *instance, uint32_t startblk,
                        const uint8_t *buffer, uint32_t n);

/**
 * @brief   Virtual methods table.
 */
static const struct MMCDriverVMT mmc_vmt = {
  (bool (*)(void *))mmc_lld_is_card_inserted,
  (bool (*)(void *))mmc_lld_is_write_protected,
  (bool (*)(void *))mmcConnect,
  (bool (*)(void *))mmcDisconnect,
  mmc_read,
  mmc_write,
  (bool (*)(void *))mmcSync,
  (bool (*)(void *, BlockDeviceInfo *))mmcGetInfo
};

/**
 * @brief   Lookup table for CRC-7 ( based on polynomial x^7 + x^3 + 1).
 */
static const uint8_t crc7_lookup_table[256] = {
  0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f, 0x48, 0x41, 0x5a, 0x53,
  0x6c, 0x65, 0x7e, 0x77, 0x19, 0x10, 0x0b, 0x02, 0x3d, 0x34, 0x2f, 0x26,
  0x51, 0x58, 0x43, 0x4a, 0x75, 0x7c, 0x67, 0x6e, 0x32, 0x3b, 0x20, 0x29,
  0x16, 0x1f, 0x04, 0x0d, 0x7a, 0x73, 0x68, 0x61, 0x5e, 0x57, 0x4c, 0x45,
  0x2b, 0x22, 0x39, 0x30, 0x0f, 0x06, 0x1d, 0x14, 0x63, 0x6a, 0x71, 0x78,
  0x47, 0x4e, 0x55, 0x5c, 0x64, 0x6d, 0x76, 0x7f, 0x40, 0x49, 0x52, 0x5b,
  0x2c, 0x25, 0x3e, 0x37, 0x08, 0x01, 0x1a, 0x13, 0x7d, 0x74, 0x6f, 0x66,
  0x59, 0x50, 0x4b, 0x42, 0x35, 0x3c, 0x27, 0x2e, 0x11, 0x18, 0x03, 0x0a,
  0x56, 0x5f, 0x44, 0x4d, 0x72, 0x7b, 0x60, 0x69, 0x1e, 0x17, 0x0c, 0x05,
  0x3a, 0x33, 0x28, 0x21, 0x4f, 0x46, 0x5d, 0x54, 0x6b, 0x62, 0x79, 0x70,
  0x07, 0x0e, 0x15, 0x1c, 0x23, 0x2a, 0x31, 0x38, 0x41, 0x48, 0x53, 0x5a,
  0x65, 0x6c, 0x77, 0x7e, 0x09, 0x00, 0x1b, 0x12, 0x2d, 0x24, 0x3f, 0x36,
  0x58, 0x51, 0x4a, 0x43, 0x7c, 0x75, 0x6e, 0x67, 0x10, 0x19, 0x02, 0x0b,
  0x34, 0x3d, 0x26, 0x2f, 0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c,
  0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04, 0x6a, 0x63, 0x78, 0x71,
  0x4e, 0x47, 0x5c, 0x55, 0x22, 0x2b, 0x30, 0x39, 0x06, 0x0f, 0x14, 0x1d,
  0x25, 0x2c, 0x37, 0x3e, 0x01, 0x08, 0x13, 0x1a, 0x6d, 0x64, 0x7f, 0x76,
  0x49, 0x40, 0x5b, 0x52, 0x3c, 0x35, 0x2e, 0x27, 0x18, 0x11, 0x0a, 0x03,
  0x74, 0x7d, 0x66, 0x6f, 0x50, 0x59, 0x42, 0x4b, 0x17, 0x1e, 0x05, 0x0c,
  0x33, 0x3a, 0x21, 0x28, 0x5f, 0x56, 0x4d, 0x44, 0x7b, 0x72, 0x69, 0x60,
  0x0e, 0x07, 0x1c, 0x15, 0x2a, 0x23, 0x38, 0x31, 0x46, 0x4f, 0x54, 0x5d,
  0x62, 0x6b, 0x70, 0x79
};

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

static bool mmc_read(void *instance, uint32_t startblk,
                uint8_t *buffer, uint32_t n) {

  if (mmcStartSequentialRead((MMCDriver *)instance, startblk)) {
    return HAL_FAILED;
  }

  while (n > 0U) {
    if (mmcSequentialRead((MMCDriver *)instance, buffer)) {
      return HAL_FAILED;
    }
    buffer += MMCSD_BLOCK_SIZE;
    n--;
  }

  if (mmcStopSequentialRead((MMCDriver *)instance)) {
    return HAL_FAILED;
  }
  return HAL_SUCCESS;
}

static bool mmc_write(void *instance, uint32_t startblk,
                 const uint8_t *buffer, uint32_t n) {

  if (mmcStartSequentialWrite((MMCDriver *)instance, startblk)) {
    return HAL_FAILED;
  }

  while (n > 0U) {
    if (mmcSequentialWrite((MMCDriver *)instance, buffer)) {
      return HAL_FAILED;
    }
    buffer += MMCSD_BLOCK_SIZE;
    n--;
  }

  if (mmcStopSequentialWrite((MMCDriver *)instance)) {
    return HAL_FAILED;
  }
  return HAL_SUCCESS;
}

/**
 * @brief Calculate the MMC standard CRC-7 based on a lookup table.
 *
 * @param[in] crc       start value for CRC
 * @param[in] buffer    pointer to data buffer
 * @param[in] len       length of data
 * @return              Calculated CRC
 */
static uint8_t crc7(uint8_t crc, const uint8_t *buffer, size_t len) {

  while (len > 0U) {
    crc = crc7_lookup_table[(crc << 1) ^ (*buffer++)];
    len--;
  }
  return crc;
}

/**
 * @brief   Waits an idle condition.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 *
 * @notapi
 */
static void wait(MMCDriver *mmcp) {
  int i;
  uint8_t buf[4];

  for (i = 0; i < 16; i++) {
    spiReceive(mmcp->config->spip, 1, buf);
    if (buf[0] == 0xFFU) {
      return;
    }
  }
  /* Looks like it is a long wait.*/
  while (true) {
    spiReceive(mmcp->config->spip, 1, buf);
    if (buf[0] == 0xFFU) {
      break;
    }
#if MMC_NICE_WAITING == TRUE
    /* Trying to be nice with the other threads.*/
    osalThreadSleepMilliseconds(1);
#endif
  }
}

/**
 * @brief   Sends a command header.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[in] cmd       the command id
 * @param[in] arg       the command argument
 *
 * @notapi
 */
static void send_hdr(MMCDriver *mmcp, uint8_t cmd, uint32_t arg) {
  uint8_t buf[6];

  /* Wait for the bus to become idle if a write operation was in progress.*/
  wait(mmcp);

  buf[0] = (uint8_t)0x40U | cmd;
  buf[1] = (uint8_t)(arg >> 24U);
  buf[2] = (uint8_t)(arg >> 16U);
  buf[3] = (uint8_t)(arg >> 8U);
  buf[4] = (uint8_t)arg;
  /* Calculate CRC for command header, shift to right position, add stop bit.*/
  buf[5] = ((crc7(0, buf, 5U) & 0x7FU) << 1U) | 0x01U;

  spiSend(mmcp->config->spip, 6, buf);
}

/**
 * @brief   Receives a single byte response.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @return              The response as an @p uint8_t value.
 * @retval 0xFF         timed out.
 *
 * @notapi
 */
static uint8_t recvr1(MMCDriver *mmcp) {
  int i;
  uint8_t r1[1];

  for (i = 0; i < 9; i++) {
    spiReceive(mmcp->config->spip, 1, r1);
    if (r1[0] != 0xFFU) {
      return r1[0];
    }
  }
  return 0xFFU;
}

/**
 * @brief   Receives a three byte response.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[out] buffer   pointer to four bytes wide buffer
 * @return              First response byte as an @p uint8_t value.
 * @retval 0xFF         timed out.
 *
 * @notapi
 */
static uint8_t recvr3(MMCDriver *mmcp, uint8_t* buffer) {
  uint8_t r1;

  r1 = recvr1(mmcp);
  spiReceive(mmcp->config->spip, 4, buffer);

  return r1;
}

/**
 * @brief   Sends a command an returns a single byte response.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[in] cmd       the command id
 * @param[in] arg       the command argument
 * @return              The response as an @p uint8_t value.
 * @retval 0xFF         timed out.
 *
 * @notapi
 */
static uint8_t send_command_R1(MMCDriver *mmcp, uint8_t cmd, uint32_t arg) {
  uint8_t r1;

  spiSelect(mmcp->config->spip);
  send_hdr(mmcp, cmd, arg);
  r1 = recvr1(mmcp);
  spiUnselect(mmcp->config->spip);
  return r1;
}

/**
 * @brief   Sends a command which returns a five bytes response (R3).
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[in] cmd       the command id
 * @param[in] arg       the command argument
 * @param[out] response pointer to four bytes wide uint8_t buffer
 * @return              The first byte of the response (R1) as an @p
 *                      uint8_t value.
 * @retval 0xFF         timed out.
 *
 * @notapi
 */
static uint8_t send_command_R3(MMCDriver *mmcp, uint8_t cmd, uint32_t arg,
                               uint8_t *response) {
  uint8_t r1;

  spiSelect(mmcp->config->spip);
  send_hdr(mmcp, cmd, arg);
  r1 = recvr3(mmcp, response);
  spiUnselect(mmcp->config->spip);
  return r1;
}

/**
 * @brief   Reads the CSD.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[out] cmd      command
 * @param[out] cxd      pointer to the CSD/CID buffer
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS  the operation succeeded.
 * @retval HAL_FAILED   the operation failed.
 *
 * @notapi
 */
static bool read_CxD(MMCDriver *mmcp, uint8_t cmd, uint32_t cxd[4]) {
  unsigned i;
  uint8_t *bp, buf[16];

  spiSelect(mmcp->config->spip);
  send_hdr(mmcp, cmd, 0);
  if (recvr1(mmcp) != 0x00U) {
    spiUnselect(mmcp->config->spip);
    return HAL_FAILED;
  }

  /* Wait for data availability.*/
  for (i = 0U; i < MMC_WAIT_DATA; i++) {
    spiReceive(mmcp->config->spip, 1, buf);
    if (buf[0] == 0xFEU) {
      uint32_t *wp;

      spiReceive(mmcp->config->spip, 16, buf);
      bp = buf;
      for (wp = &cxd[3]; wp >= cxd; wp--) {
        *wp = ((uint32_t)bp[0] << 24U) | ((uint32_t)bp[1] << 16U) |
              ((uint32_t)bp[2] << 8U)  | (uint32_t)bp[3];
        bp += 4;
      }

      /* CRC ignored then end of transaction. */
      spiIgnore(mmcp->config->spip, 2);
      spiUnselect(mmcp->config->spip);

      return HAL_SUCCESS;
    }
  }
  return HAL_FAILED;
}

/**
 * @brief   Waits that the card reaches an idle state.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 *
 * @notapi
 */
static void sync(MMCDriver *mmcp) {
  uint8_t buf[1];

  spiSelect(mmcp->config->spip);
  while (true) {
    spiReceive(mmcp->config->spip, 1, buf);
    if (buf[0] == 0xFFU) {
      break;
    }
#if MMC_NICE_WAITING == TRUE
    /* Trying to be nice with the other threads.*/
    osalThreadSleepMilliseconds(1);
#endif
  }
  spiUnselect(mmcp->config->spip);
}

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   MMC over SPI driver initialization.
 * @note    This function is implicitly invoked by @p halInit(), there is
 *          no need to explicitly initialize the driver.
 *
 * @init
 */
void mmcInit(void) {

}

/**
 * @brief   Initializes an instance.
 *
 * @param[out] mmcp         pointer to the @p MMCDriver object
 *
 * @init
 */
void mmcObjectInit(MMCDriver *mmcp) {

  mmcp->vmt = &mmc_vmt;
  mmcp->state = BLK_STOP;
  mmcp->config = NULL;
  mmcp->block_addresses = false;
}

/**
 * @brief   Configures and activates the MMC peripheral.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[in] config    pointer to the @p MMCConfig object.
 *
 * @api
 */
void mmcStart(MMCDriver *mmcp, const MMCConfig *config) {

  osalDbgCheck((mmcp != NULL) && (config != NULL));
  osalDbgAssert((mmcp->state == BLK_STOP) || (mmcp->state == BLK_ACTIVE),
                "invalid state");

  mmcp->config = config;
  mmcp->state = BLK_ACTIVE;
}

/**
 * @brief   Disables the MMC peripheral.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 *
 * @api
 */
void mmcStop(MMCDriver *mmcp) {

  osalDbgCheck(mmcp != NULL);
  osalDbgAssert((mmcp->state == BLK_STOP) || (mmcp->state == BLK_ACTIVE),
                "invalid state");

  spiStop(mmcp->config->spip);
  mmcp->state = BLK_STOP;
}

/**
 * @brief   Performs the initialization procedure on the inserted card.
 * @details This function should be invoked when a card is inserted and
 *          brings the driver in the @p MMC_READY state where it is possible
 *          to perform read and write operations.
 * @note    It is possible to invoke this function from the insertion event
 *          handler.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded and the driver is now
 *                      in the @p MMC_READY state.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcConnect(MMCDriver *mmcp) {
  unsigned i;
  uint8_t r3[4];

  osalDbgCheck(mmcp != NULL);

  osalDbgAssert((mmcp->state == BLK_ACTIVE) || (mmcp->state == BLK_READY),
                "invalid state");

  /* Connection procedure in progress.*/
  mmcp->state = BLK_CONNECTING;
  mmcp->block_addresses = false;

  /* Slow clock mode and 128 clock pulses.*/
  spiStart(mmcp->config->spip, mmcp->config->lscfg);
  spiIgnore(mmcp->config->spip, 16);

  /* SPI mode selection.*/
  i = 0;
  while (true) {
    if (send_command_R1(mmcp, MMCSD_CMD_GO_IDLE_STATE, 0) == 0x01U) {
      break;
    }
    if (++i >= MMC_CMD0_RETRY) {
      goto failed;
    }
    osalThreadSleepMilliseconds(10);
  }

  /* Try to detect if this is a high capacity card and switch to block
     addresses if possible.
     This method is based on "How to support SDC Ver2 and high capacity cards"
     by ElmChan.*/
  if (send_command_R3(mmcp, MMCSD_CMD_SEND_IF_COND,
                      MMCSD_CMD8_PATTERN, r3) != 0x05U) {

    /* Switch to SDHC mode.*/
    i = 0;
    while (true) {
      /*lint -save -e9007 [13.5] Side effect unimportant.*/
      if ((send_command_R1(mmcp, MMCSD_CMD_APP_CMD, 0) == 0x01U) &&
          (send_command_R3(mmcp, MMCSD_CMD_APP_OP_COND, 0x400001AAU, r3) == 0x00U)) {
      /*lint -restore*/
        break;
      }

      if (++i >= MMC_ACMD41_RETRY) {
        goto failed;
      }
      osalThreadSleepMilliseconds(10);
    }

    /* Execute dedicated read on OCR register */
    (void) send_command_R3(mmcp, MMCSD_CMD_READ_OCR, 0, r3);

    /* Check if CCS is set in response. Card operates in block mode if set.*/
    if ((r3[0] & 0x40U) != 0U) {
      mmcp->block_addresses = true;
    }
  }

  /* Initialization.*/
  i = 0;
  while (true) {
    uint8_t b = send_command_R1(mmcp, MMCSD_CMD_INIT, 0);
    if (b == 0x00U) {
      break;
    }
    if (b != 0x01U) {
      goto failed;
    }
    if (++i >= MMC_CMD1_RETRY) {
      goto failed;
    }
    osalThreadSleepMilliseconds(10);
  }

  /* Initialization complete, full speed.*/
  spiStart(mmcp->config->spip, mmcp->config->hscfg);

  /* Setting block size.*/
  if (send_command_R1(mmcp, MMCSD_CMD_SET_BLOCKLEN,
                      MMCSD_BLOCK_SIZE) != 0x00U) {
    goto failed;
  }

  /* Determine capacity.*/
  if (read_CxD(mmcp, MMCSD_CMD_SEND_CSD, mmcp->csd)) {
    goto failed;
  }

  mmcp->capacity = _mmcsd_get_capacity(mmcp->csd);
  if (mmcp->capacity == 0U) {
    goto failed;
  }

  if (read_CxD(mmcp, MMCSD_CMD_SEND_CID, mmcp->cid)) {
    goto failed;
  }

  mmcp->state = BLK_READY;
  return HAL_SUCCESS;

  /* Connection failed, state reset to BLK_ACTIVE.*/
failed:
  spiStop(mmcp->config->spip);
  mmcp->state = BLK_ACTIVE;
  return HAL_FAILED;
}

/**
 * @brief   Brings the driver in a state safe for card removal.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @return              The operation status.
 *
 * @retval HAL_SUCCESS   the operation succeeded and the driver is now
 *                      in the @p MMC_INSERTED state.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcDisconnect(MMCDriver *mmcp) {

  osalDbgCheck(mmcp != NULL);

  osalSysLock();
  osalDbgAssert((mmcp->state == BLK_ACTIVE) || (mmcp->state == BLK_READY),
                "invalid state");
  if (mmcp->state == BLK_ACTIVE) {
    osalSysUnlock();
    return HAL_SUCCESS;
  }
  mmcp->state = BLK_DISCONNECTING;
  osalSysUnlock();

  /* Wait for the pending write operations to complete.*/
  spiStart(mmcp->config->spip, mmcp->config->hscfg);
  sync(mmcp);

  spiStop(mmcp->config->spip);
  mmcp->state = BLK_ACTIVE;
  return HAL_SUCCESS;
}

/**
 * @brief   Starts a sequential read.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[in] startblk  first block to read
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcStartSequentialRead(MMCDriver *mmcp, uint32_t startblk) {

  osalDbgCheck(mmcp != NULL);
  osalDbgAssert(mmcp->state == BLK_READY, "invalid state");

  /* Read operation in progress.*/
  mmcp->state = BLK_READING;

  /* (Re)starting the SPI in case it has been reprogrammed externally, it can
     happen if the SPI bus is shared among multiple peripherals.*/
  spiStart(mmcp->config->spip, mmcp->config->hscfg);
  spiSelect(mmcp->config->spip);

  if (mmcp->block_addresses) {
    send_hdr(mmcp, MMCSD_CMD_READ_MULTIPLE_BLOCK, startblk);
  }
  else {
    send_hdr(mmcp, MMCSD_CMD_READ_MULTIPLE_BLOCK, startblk * MMCSD_BLOCK_SIZE);
  }

  if (recvr1(mmcp) != 0x00U) {
    spiStop(mmcp->config->spip);
    mmcp->state = BLK_READY;
    return HAL_FAILED;
  }
  return HAL_SUCCESS;
}

/**
 * @brief   Reads a block within a sequential read operation.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[out] buffer   pointer to the read buffer
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcSequentialRead(MMCDriver *mmcp, uint8_t *buffer) {
  unsigned i;

  osalDbgCheck((mmcp != NULL) && (buffer != NULL));

  if (mmcp->state != BLK_READING) {
    return HAL_FAILED;
  }

  for (i = 0; i < MMC_WAIT_DATA; i++) {
    spiReceive(mmcp->config->spip, 1, buffer);
    if (buffer[0] == 0xFEU) {
      spiReceive(mmcp->config->spip, MMCSD_BLOCK_SIZE, buffer);
      /* CRC ignored. */
      spiIgnore(mmcp->config->spip, 2);
      return HAL_SUCCESS;
    }
  }
  /* Timeout.*/
  spiUnselect(mmcp->config->spip);
  spiStop(mmcp->config->spip);
  mmcp->state = BLK_READY;
  return HAL_FAILED;
}

/**
 * @brief   Stops a sequential read gracefully.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcStopSequentialRead(MMCDriver *mmcp) {
  static const uint8_t stopcmd[] = {
    (uint8_t)(0x40U | MMCSD_CMD_STOP_TRANSMISSION), 0, 0, 0, 0, 1, 0xFF
  };

  osalDbgCheck(mmcp != NULL);

  if (mmcp->state != BLK_READING) {
    return HAL_FAILED;
  }

  spiSend(mmcp->config->spip, sizeof(stopcmd), stopcmd);
/*  result = recvr1(mmcp) != 0x00U;*/
  /* Note, ignored r1 response, it can be not zero, unknown issue.*/
  (void) recvr1(mmcp);

  /* Read operation finished.*/
  spiUnselect(mmcp->config->spip);
  mmcp->state = BLK_READY;
  return HAL_SUCCESS;
}

/**
 * @brief   Starts a sequential write.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[in] startblk  first block to write
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcStartSequentialWrite(MMCDriver *mmcp, uint32_t startblk) {

  osalDbgCheck(mmcp != NULL);
  osalDbgAssert(mmcp->state == BLK_READY, "invalid state");

  /* Write operation in progress.*/
  mmcp->state = BLK_WRITING;

  spiStart(mmcp->config->spip, mmcp->config->hscfg);
  spiSelect(mmcp->config->spip);
  if (mmcp->block_addresses) {
    send_hdr(mmcp, MMCSD_CMD_WRITE_MULTIPLE_BLOCK, startblk);
  }
  else {
    send_hdr(mmcp, MMCSD_CMD_WRITE_MULTIPLE_BLOCK,
             startblk * MMCSD_BLOCK_SIZE);
  }

  if (recvr1(mmcp) != 0x00U) {
    spiStop(mmcp->config->spip);
    mmcp->state = BLK_READY;
    return HAL_FAILED;
  }
  return HAL_SUCCESS;
}

/**
 * @brief   Writes a block within a sequential write operation.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[out] buffer   pointer to the write buffer
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcSequentialWrite(MMCDriver *mmcp, const uint8_t *buffer) {
  static const uint8_t start[] = {0xFF, 0xFC};
  uint8_t b[1];

  osalDbgCheck((mmcp != NULL) && (buffer != NULL));

  if (mmcp->state != BLK_WRITING) {
    return HAL_FAILED;
  }

  spiSend(mmcp->config->spip, sizeof(start), start);    /* Data prologue.   */
  spiSend(mmcp->config->spip, MMCSD_BLOCK_SIZE, buffer);/* Data.            */
  spiIgnore(mmcp->config->spip, 2);                     /* CRC ignored.     */
  spiReceive(mmcp->config->spip, 1, b);
  if ((b[0] & 0x1FU) == 0x05U) {
    wait(mmcp);
    return HAL_SUCCESS;
  }

  /* Error.*/
  spiUnselect(mmcp->config->spip);
  spiStop(mmcp->config->spip);
  mmcp->state = BLK_READY;
  return HAL_FAILED;
}

/**
 * @brief   Stops a sequential write gracefully.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcStopSequentialWrite(MMCDriver *mmcp) {
  static const uint8_t stop[] = {0xFD, 0xFF};

  osalDbgCheck(mmcp != NULL);

  if (mmcp->state != BLK_WRITING) {
    return HAL_FAILED;
  }

  spiSend(mmcp->config->spip, sizeof(stop), stop);
  spiUnselect(mmcp->config->spip);

  /* Write operation finished.*/
  mmcp->state = BLK_READY;
  return HAL_SUCCESS;
}

/**
 * @brief   Waits for card idle condition.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcSync(MMCDriver *mmcp) {

  osalDbgCheck(mmcp != NULL);

  if (mmcp->state != BLK_READY) {
    return HAL_FAILED;
  }

  /* Synchronization operation in progress.*/
  mmcp->state = BLK_SYNCING;

  spiStart(mmcp->config->spip, mmcp->config->hscfg);
  sync(mmcp);

  /* Synchronization operation finished.*/
  mmcp->state = BLK_READY;
  return HAL_SUCCESS;
}

/**
 * @brief   Returns the media info.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[out] bdip     pointer to a @p BlockDeviceInfo structure
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcGetInfo(MMCDriver *mmcp, BlockDeviceInfo *bdip) {

  osalDbgCheck((mmcp != NULL) && (bdip != NULL));

  if (mmcp->state != BLK_READY) {
    return HAL_FAILED;
  }

  bdip->blk_num  = mmcp->capacity;
  bdip->blk_size = MMCSD_BLOCK_SIZE;

  return HAL_SUCCESS;
}

/**
 * @brief   Erases blocks.
 *
 * @param[in] mmcp      pointer to the @p MMCDriver object
 * @param[in] startblk  starting block number
 * @param[in] endblk    ending block number
 *
 * @return              The operation status.
 * @retval HAL_SUCCESS   the operation succeeded.
 * @retval HAL_FAILED    the operation failed.
 *
 * @api
 */
bool mmcErase(MMCDriver *mmcp, uint32_t startblk, uint32_t endblk) {

  osalDbgCheck((mmcp != NULL));

  /* Erase operation in progress.*/
  mmcp->state = BLK_WRITING;

  /* Handling command differences between HC and normal cards.*/
  if (!mmcp->block_addresses) {
    startblk *= MMCSD_BLOCK_SIZE;
    endblk *= MMCSD_BLOCK_SIZE;
  }

  if (send_command_R1(mmcp, MMCSD_CMD_ERASE_RW_BLK_START, startblk) != 0x00U) {
    goto failed;
  }

  if (send_command_R1(mmcp, MMCSD_CMD_ERASE_RW_BLK_END, endblk) != 0x00U) {
    goto failed;
  }

  if (send_command_R1(mmcp, MMCSD_CMD_ERASE, 0) != 0x00U) {
    goto failed;
  }

  mmcp->state = BLK_READY;
  return HAL_SUCCESS;

  /* Command failed, state reset to BLK_ACTIVE.*/
failed:
  spiStop(mmcp->config->spip);
  mmcp->state = BLK_READY;
  return HAL_FAILED;
}

#endif /* HAL_USE_MMC_SPI == TRUE */

/** @} */