There are a lot of crappy controllers out there that cannot handle
all the request sizes that the MMC/SD/SDIO specifications require.
In case the card driver can pad the data to overcome the problems,
this commit adds a helper that calculates how much that padding
should be.
A corresponding helper is also added for SDIO, but it can also deal
with all the complexities of splitting up a large transfer efficiently.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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>
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>
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>
The classic MMC bus was defined as multi card bus
system, which is reflected in the design in the MMC
layer.
When SD showed up, the bus topology was abandoned
and a star topology (one card per host) was mandated.
MMC version 4 has followed this, officially deprecating
the bus topology.
As we do not have any known users of the bus
topology we can remove support for it. This will
simplify the code and rectify some incorrect
assumptions in the newer additions.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Thanks to the generous donation of an SDHC card by John Gilmore, and
the surprisingly enlightened decision by the SD Card Association to
publish useful specs, I've been able to bash out support for SDHC. The
changes are not too profound:
i) Add a card flag indicating the card uses block level addressing and
check it in the block driver. As we never took advantage of byte-level
addressing, this simply involves skipping the block -> byte
translation when sending commands.
ii) The layout of the CSD is changed - a set of fields are discarded
to make space for a larger C_SIZE. We did not reference any of the
discarded fields except those related to the C_SIZE.
iii) Read and write timeouts are fixed values and not calculated from
CSD values.
iv) Before invoking SEND_APP_OP_COND, we must invoke the new
SEND_IF_COND to inform the card we support SDHC.
Signed-off-by: Philipl Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
During development of SDHC support, it was discovered that the definition
for R6 was incorrect. This patch fixes that and patches the drivers that
do switch on the response type.
Signed-off-by: Philip Langdale <philipl@overt.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Pavel Pisa <ppisa@pikron.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Rather than having two places which independently calculate the
timeout for data transfers, make it a library function instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Patch from Pavel Pisa
There has been problems that for some paths that clock are not stopped
during new command programming and initiation. Result is issuing
of incorrect command to the card. Some other problems are cleaned too.
Noisy report of known ERRATUM #4 has been suppressed.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Some controllers actually check the first byte of the response (most
don't). This byte contains the command opcode for R1/R1b and all 1:s
for other types. The difference must be indicated to the controller
so it knows which reply to expect.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some hosts need to know that a transfer will be multi-block.
Add a data flag to indicate multiple data block transfers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Erik Hovland
I noticed that the same typo (i before c in associated) showed up twice
in the file kernel/include/linux/mmc/mmc.h.
This patch fixes both of the instances I found with this mistake. The
typos are in comments and should have no affect on working code.
E
Signed-off-by: Erik Hovland <erik@hovland.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Support for the Secure Digital protocol in the MMC layer.
A summary of the legal issues surrounding SD cards, as understood by yours
truly:
Members of the Secure Digital Association, hereafter SDA, are required to sign
a NDA[1] before given access to any specifications. It has been speculated
that including an SD implementation would forbid these members to redistribute
Linux. This is the basic problem with SD support so it is unclear if it even
is a problem since it has no effect on those of us that aren't members.
The SDA doesn't seem to enforce these rules though since the patches included
here are based on documentation made public by some of the members. The most
complete specs[2] are actually released by Sandisk, one of the founding
companies of the SDA.
Because of this the NDA is considered a non-issue by most involved in the
discussions concerning these patches. It might be that the SDA is only
interested in protecting the so called "secure" bits of SD, which so far
hasn't been found in any public spec. (The card is split into two sections,
one "normal" and one "secure" which has an access scheme similar to TPM:s).
(As a side note, Microsoft is working to make things easier for us since they
want to be able to include the source code for a SD driver in one of their
development kits. HP is making sure that the new NDA will allow a Linux
implementation. So far only the SDIO specs have been opened up[3]. More will
hopefully follow.)
[1] http://www.sdcard.org/membership/images/ippolicy.pdf
[2] http://www.sandisk.com/pdf/oem/ProdManualSDCardv1.9.pdf
[3] http://www.sdcard.org/sdio/Simplified%20SDIO%20Card%20Specification.pdf
This patch contains the central parts of the SD support. If no MMC cards are
found on a bus then the MMC layer proceeds looking for SD cards. Helper
functions are extended to handle the special needs of SD cards.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Pierre Ossman