sram_diskio.c

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/* Includes ------------------------------------------------------------------*/
#include <string.h>
#include "ff_gen_drv.h"

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Block Size in Bytes */
#define BLOCK_SIZE                512

/* Private variables ---------------------------------------------------------*/
/* Disk status */
static volatile DSTATUS Stat = STA_NOINIT;

/* Private function prototypes -----------------------------------------------*/
DSTATUS SRAMDISK_initialize (BYTE);
DSTATUS SRAMDISK_status (BYTE);
DRESULT SRAMDISK_read (BYTE, BYTE*, DWORD, UINT);
#if _USE_WRITE == 1
  DRESULT SRAMDISK_write (BYTE, const BYTE*, DWORD, UINT);
#endif /* _USE_WRITE == 1 */
#if _USE_IOCTL == 1
  DRESULT SRAMDISK_ioctl (BYTE, BYTE, void*);
#endif /* _USE_IOCTL == 1 */
  
const Diskio_drvTypeDef SRAMDISK_Driver =
{
  SRAMDISK_initialize,
  SRAMDISK_status,
  SRAMDISK_read, 
#if  _USE_WRITE == 1
  SRAMDISK_write,
#endif /* _USE_WRITE == 1 */  
#if  _USE_IOCTL == 1
  SRAMDISK_ioctl,
#endif /* _USE_IOCTL == 1 */
};

/* Private functions ---------------------------------------------------------*/

DSTATUS SRAMDISK_initialize(BYTE lun)
{
  Stat = STA_NOINIT;
  
  /* Configure the SRAM device */
  BSP_SRAM_Init();
  
  Stat &= ~STA_NOINIT;
  return Stat;
}

DSTATUS SRAMDISK_status(BYTE lun)
{
  Stat = STA_NOINIT;
  
  Stat &= ~STA_NOINIT;

  return Stat;
}

DRESULT SRAMDISK_read(BYTE lun, BYTE *buff, DWORD sector, UINT count)
{
  uint32_t BufferSize = (BLOCK_SIZE * count); 
  uint8_t *pSramAddress = (uint8_t *) (SRAM_DEVICE_ADDR + (sector * BLOCK_SIZE)); 
  
  for(; BufferSize != 0; BufferSize--)
  {
    *buff++ = *(__IO uint8_t *)pSramAddress++;  
  } 
  
  return RES_OK;
}

#if _USE_WRITE == 1
DRESULT SRAMDISK_write(BYTE lun, const BYTE *buff, DWORD sector, UINT count)
{
  uint32_t BufferSize = (BLOCK_SIZE * count) + count; 
  uint8_t *pSramAddress = (uint8_t *) (SRAM_DEVICE_ADDR + (sector * BLOCK_SIZE)); 
  
  for(; BufferSize != 0; BufferSize--)
  {
    *(__IO uint8_t *)pSramAddress++ = *buff++;    
  } 
  
  return RES_OK;
}
#endif /* _USE_WRITE == 1 */

#if _USE_IOCTL == 1
DRESULT SRAMDISK_ioctl(BYTE lun, BYTE cmd, void *buff)
{
  DRESULT res = RES_ERROR;
  
  if (Stat & STA_NOINIT) return RES_NOTRDY;
  
  switch (cmd)
  {
  /* Make sure that no pending write process */
  case CTRL_SYNC :
    res = RES_OK;
    break;
  
  /* Get number of sectors on the disk (DWORD) */
  case GET_SECTOR_COUNT :
    *(DWORD*)buff = SRAM_DEVICE_SIZE / BLOCK_SIZE;
    res = RES_OK;
    break;
  
  /* Get R/W sector size (WORD) */
  case GET_SECTOR_SIZE :
    *(WORD*)buff = BLOCK_SIZE;
    res = RES_OK;
    break;
  
  /* Get erase block size in unit of sector (DWORD) */
  case GET_BLOCK_SIZE :
    *(DWORD*)buff = BLOCK_SIZE;
    break;
  
  default:
    res = RES_PARERR;
  }
  
  return res;
}
#endif /* _USE_IOCTL == 1 */
  
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/