Function w25_initialize

drivers/mtd/w25.c:1444–1523

 ****************************************************************************/

FAR struct mtd_dev_s *w25_initialize(FAR struct spi_dev_s *spi)
{
  FAR struct w25_dev_s *priv;
  int ret;

  w25_finfo("spi: %p\n", spi);

  /* Allocate a state structure (we allocate the structure instead of using
   * a fixed, static allocation so that we can handle multiple FLASH devices.
   * The current implementation would handle only one FLASH part per SPI
   * device (only because of the SPIDEV_FLASH(0) definition) and so would
   * have to be extended to handle multiple FLASH parts on the same SPI bus.
   */

  priv = kmm_zalloc(sizeof(struct w25_dev_s));
  if (priv)
    {
      /* Initialize the allocated structure (unsupported methods were
       * nullified by kmm_zalloc).
       */

      priv->mtd.erase  = w25_erase;
      priv->mtd.bread  = w25_bread;
      priv->mtd.bwrite = w25_bwrite;
      priv->mtd.read   = w25_read;
      priv->mtd.ioctl  = w25_ioctl;
#if defined(CONFIG_MTD_BYTE_WRITE) && !defined(CONFIG_W25_READONLY)
      priv->mtd.write  = w25_write;
#endif
      priv->mtd.name   = "w25";
      priv->spi        = spi;

      /* Deselect the FLASH */

      SPI_SELECT(spi, SPIDEV_FLASH(0), false);

      /* Identify the FLASH chip and get its capacity */

      ret = w25_readid(priv);
      if (ret != OK)
        {
          /* Unrecognized! Discard all of that work we just did and
           * return NULL
           */

          w25_ferr("ERROR: Unrecognized\n");
          kmm_free(priv);
          return NULL;
        }
      else
        {
          /* Make sure that the FLASH is unprotected so that we can write
           * into it.
           */

#ifndef CONFIG_W25_READONLY
          w25_unprotect(priv);
#endif