%C SDMMC Driver.

Syntax:
devb-sdmmc-<variant> [cam cam_options][sdmmc sdmmc_options...][sdio sdio_options...][blk io-blk_options...] &

Options:  All options are separated by commas.

cam options:
    async=[priority]  Perform CPU cache invalidation after an I/O operation in
                   a thread at "priority". In some cases, and on some boards,
                   this can provide a performance boost.  Default off,
                   priority 21.
    bounce=[size]  This option specifies the size of bounce buffer to use.
                   The bounce buffer acts as an intermediate buffer for doing
                   transfers to/from the media. Bounce buffers are useful for
                   devices which cannot access the full range of memory
                   available to the CPU (32 vs 64-bit architecture etc).  When
                   used, size should be sufficiently large such that the CAM
                   library doesn't fragment the I/O requests from io-blk, this
                   will show markedly better performance. This option will
                   automatically be enabled when cached memory buffer usage
                   is disabled or when the hw doesn't support snooping.  The
                   size argument can include a case-insensitve suffix that
                   indicates the units: B (bytes; the default), K (kilobytes),
                   M (megabytes), or P (pages).  The default size=32k.
    cache=[on|off] Turn on/off usage of cached memory buffers.  Default on.
    lun=mask       Enable Logical Unit Number (LUN) scan for the devices
                   specified in mask. The mask is a hex bitmask specifying
                   which IDs to scan for; the default is 0x00.
    maxio=wr:rd    Set max I/O write, read blocks.  Default 4096, limited by device.
    noio           Completely remove the IO ability.  Both ThreadCtl(_NTO_TCTL_IO)
                   and ThreadCtl(_NTO_TCTL_IO_PRIV) won't be called.
    nopriv         Don't call ThreadCtl(_NTO_TCTL_IO_PRIV).
    pnp            Enable CAM plug and play (i.e. don't exit at startup when
                   no devices are found).  Default off.
    resmgr=m:l:h:d Enable /dev/camX/XXX interface and set max/lo/hi/devno
                   thread pool parameters (default: "5:1:2:-1")
    user=UID:GID   Operate as the specified user and group IDs. The driver
                   retains the necessary process-manager abilities.
    smmu=[on|off]  Turn on/off (1/0) the use of IO MMU protection services.
                   Default off.
    verbose        Be verbose: display full information about SCSI units
                   (devices) on startup.

mem options:
    name=name      Typed memory name to use.  Default sysram&below4G).
                   See also blk layer option for typed memory.

sdmmc options:
   The sdmmc options control the driver's interface to the SD/MMC device.
   If there are multiple SD/MMC devices, you can repeat these options
   for each controller. Remember, however, to specify the sdmmc keyword
   before each controller's set of options.

   bkops=[on/auto]   Value 'on' = Manual background operations (WARNING: permanent setting)
                     Value 'auto' = Device background operations.
   busno=bus         The bus number of the SDIO controller.
   bs=[options]      Set board specific options
   cache=on          Enable eMMC/SD volatile cache
   partitions=on     Enable eMMC partitions
   powman=[name]     Connect to powerman.  Dflts: No connect, [name]=devb-sdmmc-<variant>.
   priority=prio     Set the priority of the processing thread. Dflt 21.
   pwroff_notify=[short/long] Set power off notification mode for emmc [short/long].
   relwr=on          Enable eMMc reliable write. Dflt off.
   verbose=[level]   Set the sdmmc verbosity level.

sdio options:
   The sdio options control the driver's interface to the SD/MMC host
   controller.  If there are multiple host controllers, you can repeat
   these options for each controller. Remember, however, to specify
   the sdio keyword before each controller's set of options.

   verbose=[level]   Set the sdio verbosity level.
   hc=name           Name of host controller.
   vid=vid           The vendor id of the controller.
   did=did           The device id of the controller.
   idx=idx           The index of the controller in the machine, where
                     idx is a value between 0 and the number of adapters.
   addr=addr         The address of the interface.
   irq=req           The interrupt used by the controller.
   dma=chnl          The DMA channel to use.
   clk=clk           Set the operational clock.
   ~bmstr            Disable DMA.
   ~ac12             Disable AC12.  Dflt on.
   ~ac23             Disable AC23.  Dflt on.
   bw=[~]bw          Set/Clear bus widths (4, 8).
   timing=[~]timing  Set/Clear timings (hs, ddr, sdr12, sdr25, sdr50, sdr104, hs200, hs400, hs400es).
   pm=idle:sleep     Set the pwr mgnt idle/sleep time in ms. Dflt 100:10000 ms.
   emmc              eMMC device is connected to the interface
   hs=options        Host specific options.
   bs=options        Board specific options.
   nowp              Disable write protect detection.
   drv_type=drv_type Driver strength value for the HS_TIMING register (0, 1, 2, 3, 4). Dflt 0.

