The disk_ioctl function is called to control device specific features and miscellaneous functions other than generic read/write.
++DRESULT disk_ioctl ( + BYTE pdrv, /* [IN] Drive number */ + BYTE cmd, /* [IN] Control command code */ + void* buff /* [I/O] Parameter and data buffer */ +); ++
The FatFs module requires only five device independent commands described below.
+| Command | Description |
|---|---|
| CTRL_SYNC | Make sure that the device has finished pending write process. If the disk I/O module has a write back cache, the dirty buffers must be written back to the media immediately. Nothing to do for this command if each write operation to the media is completed within the disk_write function. |
| GET_SECTOR_COUNT | Returns number of available sectors on the drive into the DWORD variable pointed by buff. This command is used by f_mkfs and f_fdisk function to determine the volume/partition size to be created. Required at FF_USE_MKFS == 1. |
| GET_SECTOR_SIZE | Returns sector size of the device into the WORD variable pointed by buff. Valid return values for this command are 512, 1024, 2048 and 4096. This command is required only if FF_MAX_SS > FF_MIN_SS. When FF_MAX_SS == FF_MIN_SS, this command is never used and the device must work at that sector size. |
| GET_BLOCK_SIZE | Returns erase block size of the flash memory media in unit of sector into the DWORD variable pointed by buff. The allowable value is 1 to 32768 in power of 2. Return 1 if the erase block size is unknown or non flash memory media. This command is used by only f_mkfs function and it attempts to align data area on the erase block boundary. Required at FF_USE_MKFS == 1. |
| CTRL_TRIM | Informs the device the data on the block of sectors is no longer needed and it can be erased. The sector block is specified by a DWORD array {<start sector>, <end sector>} pointed by buff. This is an identical command to Trim of ATA device. Nothing to do for this command if this funcion is not supported or not a flash memory device. FatFs does not check the result code and the file function is not affected even if the sector block was not erased well. This command is called on remove a cluster chain and in the f_mkfs function. Required at FF_USE_TRIM == 1. |
FatFs never uses any device dependent command nor user defined command. Following table shows an example of non-standard commands which may be useful for some applications.
+| Command | Description |
|---|---|
| CTRL_FORMAT | Create a physical format on the media. If buff is not null, it is pointer to the call-back function for progress notification. |
| CTRL_POWER_IDLE | Put the device idle state. STA_NOINIT in the current status flags may not be set if the device goes active state by generic read/write function. |
| CTRL_POWER_OFF | Put the device off state. Shut-down the power to the device and deinitialize the device interface if needed. STA_NOINIT in the current status flags must be set. The device goes active state by disk_initialize function. |
| CTRL_LOCK | Lock media eject mechanism. |
| CTRL_UNLOCK | Unlock media eject mechanism. |
| CTRL_EJECT | Eject media cartridge. STA_NOINIT and STA_NODISK in status flag are set after the function succeeded. |
| CTRL_GET_SMART | Read SMART information. |
| MMC_GET_TYPE | Get card type. The type flags, bit0:MMCv3, bit1:SDv1, bit2:SDv2+ and bit3:LBA, is stored to a BYTE variable pointed by buff. (MMC/SDC specific command) |
| MMC_GET_CSD | Read CSD register into a 16-byte buffer pointed by buff. (MMC/SDC specific command) |
| MMC_GET_CID | Read CID register into a 16-byte buffer pointed by buff. (MMC/SDC specific command) |
| MMC_GET_OCR | Read OCR register into a 4-byte buffer pointed by buff. (MMC/SDC specific command) |
| MMC_GET_SDSTAT | Read SDSTATUS register into a 64-byte buffer pointed by buff. (SDC specific command) |
| ATA_GET_REV | Get the revision string into a 16-byte buffer pointed by buff. (ATA/CFC specific command) |
| ATA_GET_MODEL | Get the model string into a 40-byte buffer pointed by buff. (ATA/CFC specific command) |
| ATA_GET_SN | Get the serial number string into a 20-byte buffer pointed by buff. (ATA/CFC specific command) |
| ISDIO_READ | Read a block of iSDIO registers specified by command structure pointed by buff. (FlashAir specific command) |
| ISDIO_WRITE | Write a block of data to iSDIO registers specified by command structure pointed by buff. (FlashAir specific command) |
| ISDIO_MRITE | Change bits in an iSDIO register specified by command structure pointed by buff. (FlashAir specific command) |
The disk_ioctl function is not needed when FF_FS_READONLY == 1 and FF_MAX_SS == FF_MIN_SS.
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