Teach the MMC/SD/SDIO system headers that some hosts use SPI mode

 - New host capabilities and status bits
    * MMC_CAP_SPI, with mmc_host_is_spi() test
    * mmc_host.use_spi_crc flag

 - SPI-specific declarations:
    * Response types, MMC_RSP_SPI_R*
    * Two SPI-only commands
    * Status bits used native to SPI:  R1_SPI_*, R2_SPI_*

 - Fix a few (unrelated) whitespace bugs in the headers.

 - Reorder a few mmc_host fields, removing several bytes of padding

None of these changes affect current code.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

It is sometimes necessary to give up on trying to claim the host lock,
especially if that happens in a thread that has to be stopped.

While at it, fix the description for mmc_claim_host() which was wrong.

Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

Really basic init sequence for SDIO cards.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

The MMC_DATA_MULTI flag never had a proper definition of what it
means, so remove it and let the drivers check the block count in
the request.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

The write parameter in mmc_set_data_timeout() is redundant as the
data structure contains information about the direction of the
transfer.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

Convert the MMC layer to use standard error codes and not its own,
incompatible values.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

Make sure the kerneldoc comments are up to date and relevant.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

Move protocol operations and definitions into their own files
in an effort to separate protocol handling and bus
arbitration more clearly.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

Create a "core" subdirectory to house the central bus handling
functions.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>