When CONFIG_DEBUG_FS is set, create a few files under /sys/kernel/debug
containing information about an mmc host's internal state. Currently,
just a single file is created, "ios", which contains information about
the current operating parameters for the bus (clock speed, bus width,
etc.)
Host drivers can add additional files and directories under the host's
root directory by passing the debugfs_root field in struct mmc_host as
the 'parent' parameter to debugfs_create_*.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Relax requirements on host controllers and only require that they do not
report a transfer count than is larger than the actual one (i.e. a lower
value is okay). This is how many other parts of the kernel behaves so
upper layers should already be prepared to handle that scenario. This
gives us a performance boost on MMC cards.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Now get_ro() callback must return 0/1 values for its logical states, and
negative errno values in case of error. If particular host instance doesn't
support RO/WP switch, it should return -ENOSYS.
This patch changes some hosts in two ways:
1. Now functions should be smart to not return negative values in
"RO asserted" case (particularly gpio_ calls could return negative
values for the outermost GPIOs).
Also, board code usually passes get_ro() callbacks that directly return
gpioreg & bit result, so at91_mci, imxmmc, pxamci and mmc_spi's get_ro()
handlers need take special care when returning platform's values to the
mmc core.
2. In case of host instance didn't implement get_ro() callback, it should
really return -ENOSYS and let the mmc core decide what to do about it
(mmc core thinks the same way as the hosts, so it isn't functional
change).
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some hosts (and boards that use mmc_spi) do not use interrupts on the CD
line, so they can't trigger mmc_detect_change. We want to poll the card
and see if there was a change. 1 second poll interval seems resonable.
This patch also implements .get_cd() host operation, that could be used
by the hosts that are able to report card-detect status without need to
talk MMC.
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This field and corresponding defines are simply never used anywhere
in the code. But its mere presence is enough to confuse some host
driver authors who attempt to rely on it. Let's eliminate the
possibility for confusion and remove it entirely.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Add a led trigger for each host controller that indicates if there
is a request active on the controller.
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
This fixes u32 vs. pm_message_t confusion in remaining places. Fortunately
there's few of them.
Signed-off-by: Pavel Machek <pavel@suse.cz>
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!
Haavard Skinnemoen