Fix handling of low voltage MMC cards.
The latest MMC and SD specs both agree that support for
low-voltage operations is indicated by bit 7 in the OCR.
The MMC spec states that the low voltage range is
1.65-1.95V while the SD spec leaves the actual voltage
range undefined - meaning that there is still no such
thing as a low voltage SD card.
However, an old Sandisk spec implied that bits 7.0
represented voltages below 2.0V in 1V or 0.5V increments,
and the code was accordingly written with that expectation.
This confusion meant that host drivers attempting to support
the typical low voltage (1.8V) would set the wrong bits in
the host OCR mask (usually bits 5 and/or 6) resulting in the
the low voltage mode never being used.
This change corrects the low voltage range and adds sanity
checks on the reserved bits (0-6) and for SD cards that
claim to support low-voltage operations.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Consolidate the list of available voltages.
Up until now, a separate set of defines has been
used for host->vdd than that used for the OCR
voltage mask values. Having two sets of defines
allows them to get out of sync and the current
sets are already inconsistent with one claiming
to describe ranges and the other specific voltages.
Only the SDHCI driver uses the host->vdd defines and
it is easily fixed to use the OCR defines.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Delegate protocol handling to "bus handlers". This allows the core to
just handle the task of arbitrating the bus. Initialisation and
pampering of cards is now done by the different bus handlers.
This design also allows MMC and SD (and later SDIO) to be more cleanly
separated, allowing easier maintenance.
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>
Make sure we kill of any pending detection runs when the host
is removed instead of when it is freed. Also add some debugging
to make sure the driver doesn't queue up more detection after it
has removed the host.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
All host drivers were #include:ing mmc/protocol.h just to
get access to the OCR bit defines. Move these to host.h instead.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Support for MMC 4.2 sector based cards. This tweaks the init a
bit and reads a new field out of the EXT_CSD.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The new high-speed timings are similar to each other and the old
system, but not identical. And although things "just work" most of
the time, sometimes it does not. So we need to start marking which
hosts are known to fully comply with the new timings.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Many controllers have an upper limit on the number of blocks that can be
transferred in one request. Allow the host drivers to specify this and make
sure we avoid hitting this limit.
Also change the max_sectors field to avoid confusion. This makes it map
less directly to the block layer limits, but as they didn't apply directly
on MMC cards anyway, this isn't a great loss.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Most controllers have an upper limit on the block size. Allow the host
drivers to specify this and make sure we avoid hitting this limit.
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>
Change the parent of cards to be a specific host (a class
device), not the physical controller. This is particularly
useful when the hardware has multiple slots, meaning
multiple hosts.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
As card_busy was only used to indicate if the host was exclusively
claimed and not really used to identify a particular card, replacing
it with just a boolean makes things a lot more easily understandable.
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>
Converts from using struct "class_device" to "struct device" making
everything show up properly in /sys/devices/ with symlinks from the
/sys/class directory.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Modern SD cards support a clock speed of 50 MHz. Make sure we test for
this capability and do the song and dance required to activate it.
Activating high speed support actually modifies the TRAN_SPEED field
of the CSD. But as the spec says that the cards must report 50 MHz,
we might as well skip re-reading the CSD.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This change adds support for the mmc4 4-bit wide-bus mode.
The mmc4 spec defines 8-bit and 4-bit transfer modes. As we do not support
any 8-bit hardware, this patch only adds support for the 4-bit mode, but
it can easily be built upon when the time comes.
The 4-bit mode is electrically compatible with SD's 4-bit mode but the
procedure for turning it on is different. This patch implements only
the essential parts of the procedure as defined by the spec. Two additional
steps are recommended but not compulsory. I am documenting them here so
that there's a record.
1) A bus-test mechanism is implemented using dedicated mmc commands which allow
for testing the functionality of the data bus at the electrical level. This is
pretty paranoid and they way the commands work is not compatible with the mmc
subsystem (they don't set valid CRC values).
2) MMC v4 cards can indicate they would like to draw more than the default
amount of current in wide-bus modes. We currently will never switch the card
into a higher draw mode. Supposedly, allowing the card to draw more current
will let it perform better, but the specs seem to indicate that the card will
function correctly without the mode change. Empirical testing supports this
interpretation.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This adds support for the high-speed modes defined by mmc v4
(assuming the host controller is up to it). On a TI sdhci controller,
it improves read speed from 1.3MBps to 2.3MBps. The TI controller can
only go up to 24MHz, but everything helps. Another person has taken
this basic patch and used it on a Nokia 770 to get a bigger boost
because that controller can run at 48MHZ.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
SD cards extend the protocol by allowing the host to query a card how many
blocks were successfully stored on the medium. This allows us to safely write
chunks of blocks at once.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some MMC hosts can only handle log2 block sizes. Unfortunately,
the MMC password support needs to be able to send non-log2 block
sizes. Provide a capability so that the MMC password support can
decide whether it should use this support or not.
The unfortunate side effect of this host limitation is that any
MMC card protected by a password which is not a log2 block size
can not be accessed on a host which only allows a log2 block size.
This change just adds the flag. The MMC password support code
needs updating to use it (if and when it is finally submitted.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add a capability flag for drivers to set when they can perform multi-
block transfers to cards _and_ correctly report the number of bytes
transferred should an error occur.
The last point is very important - if a driver reports more bytes than
were actually accepted by the card and an error occurs, there is the
possibility for data loss.
Pierre Ossman provided the patch for wbsd and sdhci.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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>
Let drivers constify MMC host method operations tables,
moving them from ".data" to ".rodata".
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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>
The CSD contains a "read2write factor" which determines the multiplier to
be applied to the read timeout to obtain the write timeout. We were
ignoring this parameter, resulting in the possibility for writes being
timed out too early.
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>
Select a block size for IO based on the read and write block size
combinations, and whether the card supports partial block reads
and/or partial block writes.
If we are able to satisfy block reads but not block writes, mark
the device read only.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
A review against MMC/SD specifications found some errors in the current
implementation.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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>
mmc_priv() has some nasty effects if the wrong pointer type is
passed to it. Introduce type checking, which also means we get
the right type. Also add an additional member to mmc_host which
is used to align host-private data appropriately.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Change mmc_detect_change() to take a delay argument such that
the detection of card insertions and removals can be delayed
according to the requirements of the host driver or platform.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Infrastructure for 4-bit bus transfers with 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>
Read the SD specific SCR register from the card.
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>
Support for the read-only switch on SD cards which must be enforced by the
host.
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>
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>
Adds a new ios for setting the chip select pin on MMC cards. Needed on
SD controllers which use this pin for other things and therefore cannot
have it pulled high at all times.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There's no point in having the host name duplicated between
the mmc_host structure and the encapsulated class device
structure.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Create a mmc_host class to allow enumeration of MMC host controllers
even though they have no card(s) inserted.
Patch based on work by Pierre Ossman.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pierre Ossman