SD/MMC cards tend to support an erase operation. In addition, eMMC v4.4
cards can support secure erase, trim and secure trim operations that are
all variants of the basic erase command.
SD/MMC device attributes "erase_size" and "preferred_erase_size" have been
added.
"erase_size" is the minimum size, in bytes, of an erase operation. For
MMC, "erase_size" is the erase group size reported by the card. Note that
"erase_size" does not apply to trim or secure trim operations where the
minimum size is always one 512 byte sector. For SD, "erase_size" is 512
if the card is block-addressed, 0 otherwise.
SD/MMC cards can erase an arbitrarily large area up to and
including the whole card. When erasing a large area it may
be desirable to do it in smaller chunks for three reasons:
1. A single erase command will make all other I/O on the card
wait. This is not a problem if the whole card is being erased, but
erasing one partition will make I/O for another partition on the
same card wait for the duration of the erase - which could be a
several minutes.
2. To be able to inform the user of erase progress.
3. The erase timeout becomes too large to be very useful.
Because the erase timeout contains a margin which is multiplied by
the size of the erase area, the value can end up being several
minutes for large areas.
"erase_size" is not the most efficient unit to erase (especially for SD
where it is just one sector), hence "preferred_erase_size" provides a good
chunk size for erasing large areas.
For MMC, "preferred_erase_size" is the high-capacity erase size if a card
specifies one, otherwise it is based on the capacity of the card.
For SD, "preferred_erase_size" is the allocation unit size specified by
the card.
"preferred_erase_size" is in bytes.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you don't use CONFIG_MMC_UNSAFE_RESUME, as soon as you attempt to
suspend, the card will be removed, therefore this patch doesn't change the
behavior of this option.
However the removal will be done by pm notifier, which runs while
userspace is still not frozen and thus can freely use del_gendisk, without
the risk of deadlock which would happen otherwise.
Card detect workqueue is now disabled while userspace is frozen, Therefore
if you do use CONFIG_MMC_UNSAFE_RESUME, and remove the card during
suspend, the removal will be detected as soon as userspace is unfrozen,
again at the moment it is safe to call del_gendisk.
Tested with and without CONFIG_MMC_UNSAFE_RESUME with suspend and hibernate.
[akpm@linux-foundation.org: clean up function prototype]
[akpm@linux-foundation.org: fix CONFIG_PM-n linkage, small cleanups]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Even though many mmc host drivers pass a pm_message_t argument to
mmc_suspend_host() that argument isn't used the by MMC core. As host
drivers are converted to dev_pm_ops they'll have to construct
pm_message_t's (as they won't be passed by the PM subsystem any more) just
to appease the mmc suspend interface.
We might as well just delete the unused paramter.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>ZZ
Acked-by: Sascha Sommer <saschasommer@freenet.de>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MX3 SoCs have a silicon bug which corrupts CRC calculation of
multi-block transfers when connected SDIO peripheral doesn't drive the
BUSY line as required by the specs.
One way to prevent this is to only allow 1-bit transfers.
Another way is playing tricks with the DMA engine, but this isn't
mainline yet. So for now, we live with the performance drawback of 1-bit
transfers until a nicer solution is found.
This patch introduces a new host controller callback 'init_card' which
is for now only called from mmc_sdio_init_card().
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Volker Ernst <volker.ernst@txtr.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Michał Mirosław <mirqus@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch series provides the core changes needed to allow SDIO cards to
remain powered and active while the host system is suspended, and let them
wake up the host system when needed. This is used to implement
wake-on-lan with SDIO wireless cards at the moment. Patches to add that
support to the libertas driver will be posted separately.
This patch:
Some SDIO cards have the ability to keep on running autonomously when the
host system is suspended, and wake it up when needed. This however
requires that the host controller preserve power to the card, and
configure itself appropriately for wake-up.
There is however 4 layers of abstractions involved: the host controller
driver, the MMC core code, the SDIO card management code, and the actual
SDIO function driver. To make things simple and manageable, host drivers
must advertise their PM capabilities with a feature bitmask, then function
drivers can query and set those features from their suspend method. Then
each layer in the suspend call chain is expected to act upon those bits
accordingly.
[akpm@linux-foundation.org: fix typo in comment]
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Add support for the new MMC command SLEEP_AWAKE.
Signed-off-by: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Power can be saved by powering off cards that are not in use. This is
similar to suspend / resume except it is under the control of the driver,
and does not require any power management support. It can only be used
when the driver can monitor whether the card is removed, otherwise it is
unsafe. This is possible because, unlike suspend, the driver still
receives card detect and / or cover switch interrupts.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
eMMC's are not removable, so unsafe resume is OK always.
To permit this a new host capability MMC_CAP_NONREMOVABLE has been added
and suspend / resume updated accordingly.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This change allows the MMC host to be claimed in situations where the host
may or may not have already been claimed. Also 'mmc_try_claim_host()' is
now exported.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MMC hosts that support power saving can use the 'enable' and 'disable'
methods to exit and enter power saving states. An explanation of their
use is provided in the comments added to include/linux/mmc/host.h.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Glue between MMC and regulator stacks ... verified with
some OMAP3 boards using adjustable and configured-as-fixed
regulators on several MMC controllers.
These calls are intended to be used by MMC host adapters
using at least one regulator per host. Examples include
slots with regulators supporting multiple voltages and
ones using multiple voltage rails (e.g. DAT4..DAT7 using a
separate supply, or a split rail chip like certain SDIO
WLAN or eMMC solutions).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
In include/linux/mmc/host.h, it is mentionned that the callback to
know if a card is present or not is get_ro(). But it's get_cd().
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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>
Conflicts:
drivers/infiniband/core/iwcm.c
drivers/net/chelsio/cxgb2.c
drivers/net/wireless/bcm43xx/bcm43xx_main.c
drivers/net/wireless/prism54/islpci_eth.c
drivers/usb/core/hub.h
drivers/usb/input/hid-core.c
net/core/netpoll.c
Fix up merge failures with Linus's head and fix new compilation failures.
Signed-Off-By: David Howells <dhowells@redhat.com>
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>
