Instead of checking for "#ifdef" directly in the code, let's invent a pair
of mmc core functions to deal with register/unregister the MMC PM notifier
block. Implement stubs for these functions when CONFIG_PM_SLEEP is unset,
as in that case the PM notifiers isn't used.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

MMC_CLKGATE was once invented to save power by gating the bus clock at
request inactivity. At that time it served its purpose. The modern way to
deal with power saving for these scenarios, is by using runtime PM.

Nowadays, several host drivers have deployed runtime PM, but for those
that haven't and which still cares power saving at request inactivity,
it's certainly time to deploy runtime PM as it has been around for several
years now.

To simplify code to mmc core and thus decrease maintenance efforts, this
patch removes all code related to MMC_CLKGATE.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>

Make a new function out of common code used for drive
strength selection.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

HS400 re-tuning must be done in HS200 mode. Add
the ability to switch from HS400 mode to HS200
mode before re-tuning and switch back to HS400
after re-tuning.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

For each MMC, SD and SDIO there is code that
holds the clock, calls ops->execute_tuning, and
releases the clock. Simplify the code a bit by
providing a separate function to do that.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Move the (e)MMC specific hw_reset code from core.c into mmc.c. Call the
code from the new bus_ops member "reset". This also allows for adding
a SD card specific reset procedure.
Signed-off-by: NJohan Rudholm <johanru@axis.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

This adds SDIO devicetree subnode parsing to the mmc core. While
SDIO devices are runtime probable they sometimes need nonprobable
additional information on embedded systems, like an additional gpio
interrupt or a clock. This patch makes it possible to supply this
information from the devicetree. SDIO drivers will find a pointer
to the devicenode in their devices of_node pointer.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
[hdegoede@redhat.com: Misc. cleanups]
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

mmc_do_hw_reset(), mmc_power_up() and mmc_power_off() all set similar
initial values for bus_mode, bus_width, chip_select and timing. Let's
make this handling simpler and more consistent by sticking them
together in a common function. This will introduce small changes in
behavior in the following places:

mmc_power_off():

  For SPI hosts, explicitly set bus_mode = MMC_BUSMODE_PUSHPULL and
  chip_select = MMC_CS_HIGH, before we left them as they were.

  For non-SPI hosts, set bus_mode = MMC_BUSMODE_PUSHPULL instead of
  MMC_BUSMODE_OPENDRAIN as before.

  These two changes should not be a problem since the device will be
  powered off anyway.

mmc_do_hw_reset():

  Always set bus_mode = MMC_BUSMODE_PUSHPULL, as required by SD/SDIO
  cards. MMC cards require MMC_BUSMODE_OPENDRAIN, but this is taken
  care of by mmc_init_card() and mmc_attach_mmc().
Signed-off-by: NJohan Rudholm <johanru@axis.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

This is yet another step of restructure code to be able to fixup the
setup of the negotiated ocr mask.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

As a step to fixup the setup of the negotiated ocr mask, we need the
mmc_power_up|cycle functions to take the ocr as a parameter.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

By adding an optional .shutdown callback to the bus_ops struct we
provide the possibility to let each bus type handle it's shutdown
requirements.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

This patch moves the validation for all the suspend prerequisites to be
done at SUSPEND_PREPARE notification. Previously in the SDIO case parts
of the validation was done from mmc_suspend_host.

This patch invents a new pre_suspend bus_ops callback and implements it
for SDIO. Returning an error code from it, will mean at SUSPEND_PREPARE
notification, the card will be removed before proceeding with the
suspend sequence.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

The mmc_card_sleep|awake APIs are not being used since the support is
already properly encapsulated within the suspend sequence. Sleep|awake
command is also specific for eMMC.

We remove the sleep|awake bus_ops, the mmc_card_sleep|awake APIs and
move the code into the mmc specific core instead. This also includes
the mmc ops function, mmc_sleepawake. All releated functions have then
become static and we have got far less code to maintain.

Additionally this patch also simplifies the code from mmc_sleepawake,
since it is only used to put the card to sleep and not awake.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

SDIO is the only protocol that uses runtime pm for the card device
right now. To provide the option for sd and mmc to use runtime pm as
well the bus_ops callback are extended with two new functions. One for
runtime_suspend and one for runtime_resume.

This patch will also implement the callbacks for SDIO to make sure
existing functionality is maintained. It also prepares to move
away from using the mmc_power_restore_host API, since it is not
needed when using runtime PM.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Allow callers to access the start_signal_voltage_switch host_ops
member without going through any cmd11 logic. This is mostly a
preparation for the following signal voltage switch patch.

Also, reset ios.signal_voltage to its original value if
start_signal_voltage_switch fails.
Signed-off-by: NJohan Rudholm <johan.rudholm@stericsson.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NWei WANG <wei_wang@realsil.com.cn>
Signed-off-by: NChris Ball <cjb@laptop.org>

Add mmc_power_cycle which can be used to power cycle for instance
SD-cards.
Signed-off-by: NJohan Rudholm <johan.rudholm@stericsson.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NWei WANG <wei_wang@realsil.com.cn>
Signed-off-by: NChris Ball <cjb@laptop.org>

When current request is running on the bus and if next request fetched
by mmcqd is NULL, mmc context (mmcqd thread) gets blocked until the
current request completes. This means that if new request comes in while
the mmcqd thread is blocked, this new request can not be prepared in
parallel to current ongoing request. This may result in delaying the new
request execution and increase it's latency.

This change allows to wake up the MMC thread on new request arrival.
Now once the MMC thread is woken up, a new request can be fetched and
prepared in parallel to the current running request which means this new
request can be started immediately after the current running request
completes.

With this change read throughput is improved by 16%.
Signed-off-by: NKonstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

When current request is running on the bus and if next request fetched
by mmcqd is NULL, mmc context (mmcqd thread) gets blocked until the
current request completes. This means that if new request comes in while
the mmcqd thread is blocked, this new request can not be prepared in
parallel to current ongoing request. This may result in delaying the new
request execution and increase it's latency.

This change allows to wake up the MMC thread on new request arrival.
Now once the MMC thread is woken up, a new request can be fetched and
prepared in parallel to the current running request which means this new
request can be started immediately after the current running request
completes.

With this change read throughput is improved by 16%.
Signed-off-by: NKonstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Add a function mmc_detect_card_removed() which upper layers can use to
determine immediately if a card has been removed. This function should
be called after an I/O request fails so that all queued I/O requests
can be errored out immediately instead of waiting for the card device
to be removed.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NSujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

During a rescan operation mmc_attach(sd|mmc|sdio) functions are
called. The error handling in these function can trigger a detach
of the bus, which also meant a power off. This is not notified by
the rescan operation which then continues to the next attach function.

If a power off has been done, the framework must never send any
new commands to the host driver, without first doing a new power up.
This will most likely trigger any host driver to hang.

Moving power off out of detach and instead handle power off
separately when it is actually needed, solves the issue.
Signed-off-by: NUlf Hansson <ulf.hansson@stericsson.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: <stable@kernel.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

eMMC voltage change not required for 1.8V.  3.3V and 1.8V vcc
are capable of doing DDR. vccq of 1.8v is not required.
Signed-off-by: NPhilip Rakity <prakity@marvell.com>
Reviewed-by: NArindam Nath <arindam.nath@amd.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

eMMC chips do not use CMD11 when changing voltage.  Add extra
argument to call to indicate if CMD11 needs to be sent.
Signed-off-by: NPhilip Rakity <prakity@marvell.com>
Reviewed-by: NArindam Nath <arindam.nath@amd.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

This patch adds support for setting driver strength during UHS-I
initialization procedure. Since UHS-I cards set S18A (bit 24) in
response to ACMD41, we use this as a base for UHS-I initialization.
We modify the parameter list of mmc_sd_get_cid() so that we can
save the ROCR from ACMD41 to check whether bit 24 is set.

We decide whether the Host Controller supports A, C, or D driver
type depending on the Capabilities register. Driver type B is
suported by default. We then set the appropriate driver type for
the card using CMD6 mode 1. As per Host Controller spec v3.00, we
set driver type for the host only if Preset Value Enable in the
Host Control2 register is not set. SDHCI_HOST_CONTROL has been
renamed to SDHCI_HOST_CONTROL1 to conform to the spec.

Tested by Zhangfei Gao with a Toshiba uhs card and general hs card,
on mmp2 in SDMA mode.
Signed-off-by: NArindam Nath <arindam.nath@amd.com>
Reviewed-by: NPhilip Rakity <prakity@marvell.com>
Tested-by: NPhilip Rakity <prakity@marvell.com>
Acked-by: NZhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

Host Controller v3.00 adds another Capabilities register. Apart
from other things, this new register indicates whether the Host
Controller supports SDR50, SDR104, and DDR50 UHS-I modes. The spec
doesn't mention about explicit support for SDR12 and SDR25 UHS-I
modes, so the Host Controller v3.00 should support them by default.
Also if the controller supports SDR104 mode, it will also support
SDR50 mode as well. So depending on the host support, we set the
corresponding MMC_CAP_* flags. One more new register. Host Control2
is added in v3.00, which is used during Signal Voltage Switch
procedure described below.

Since as per v3.00 spec, UHS-I supported hosts should set S18R
to 1, we set S18R (bit 24) of OCR before sending ACMD41. We also
need to set XPC (bit 28) of OCR in case the host can supply >150mA.
This support is indicated by the Maximum Current Capabilities
register of the Host Controller.

If the response of ACMD41 has both CCS and S18A set, we start the
signal voltage switch procedure, which if successfull, will switch
the card from 3.3V signalling to 1.8V signalling. Signal voltage
switch procedure adds support for a new command CMD11 in the
Physical Layer Spec v3.01. As part of this procedure, we need to
set 1.8V Signalling Enable (bit 3) of Host Control2 register, which
if remains set after 5ms, means the switch to 1.8V signalling is
successfull. Otherwise, we clear bit 24 of OCR and retry the
initialization sequence. When we remove the card, and insert the
same or another card, we need to make sure that we start with 3.3V
signalling voltage. So we call mmc_set_signal_voltage() with
MMC_SIGNAL_VOLTAGE_330 set so that we are back to 3.3V signalling
voltage before we actually start initializing the card.

Tested by Zhangfei Gao with a Toshiba uhs card and general hs card,
on mmp2 in SDMA mode.
Signed-off-by: NArindam Nath <arindam.nath@amd.com>
Reviewed-by: NPhilip Rakity <prakity@marvell.com>
Tested-by: NPhilip Rakity <prakity@marvell.com>
Acked-by: NZhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

The current mechanism is SDIO-only. This allows us to create
function-specific quirks, without creating messy Kconfig dependencies,
or polluting core/ with function-specific code.
Signed-off-by: NAndrei Warkentin <andreiw@motorola.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

Some cards have quirks valid for every platforms using current
platform quirk hooks leads to a lot of code and debug duplication.

So we inspire a bit from what exists in PCI subsystem and do our own
per vendorid/deviceid quirk.  We still drop the complexity of the pci
quirk system (with special section tables, and so on).
That can be added later if needed.
Signed-off-by: NPierre Tardy <pierre.tardy@intel.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

Rewrite and clean up mmc_rescan() to properly retry frequencies lower
than 400kHz.  Failures can happen both in sd_send_* calls and
mmc_attach_*.  Break out "mmc_rescan_try_freq" from the frequency
selection loop.  Symmetrize claim/release logic in mmc_attach_* API,
and move the sd_send_* calls there to make mmc_rescan easier to read.
Signed-off-by: NAndy Ross <andy.ross@windriver.com>
Reviewed-and-Tested-by: NHein Tibosch <hein_tibosch@yahoo.es>
Reviewed-by: NChris Ball <cjb@laptop.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

This patch modifies the MMC core code to optionally call the set_ios()
operation on the driver with the clock frequency set to 0 (gate) after
a grace period of at least 8 MCLK cycles, then restore it (ungate)
before any new request. This gives the driver the option to shut down
the MCI clock to the MMC/SD card when the clock frequency is 0, i.e.
the core has stated that the MCI clock does not need to be generated.

It is inspired by existing clock gating code found in the OMAP and
Atmel drivers and brings this up to the host abstraction.  Gating is
performed before and after any MMC request.

This patchset implements this for the MMCI/PL180 MMC/SD host controller,
but it should be simple to switch OMAP/Atmel over to using this instead.

mmc_set_{gated,ungated}() add variable protection to the state holders
for the clock gating code.  This is particularly important when ordinary
.set_ios() calls would race with the .set_ios() call resulting from a
delayed gate operation.
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Reviewed-by: NChris Ball <cjb@laptop.org>
Tested-by: NChris Ball <cjb@laptop.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Allow power save/restore and their relevant mmc_bus_ops handlers
exit with a return value.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Tested-by: NLuciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

One flaw with DDR support is that MMC core does not inform the driver
which DDR mode it has selected.  This patch expands the ios->ddr flag
to do that.
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

The DDR support patch needs the following fixes:

- The block driver does not need to know about DDR, any more
  than it needs to know about bus width.
- Not only the card must be switched to DDR mode.  The host
  controller must also be configured, which is done through
  the 'set_ios()' function.
- Do not set the DDR mode state until after the switch command
  is successful.
- Setting block length is not supported in DDR mode.  Make that
  a core function and change the other place it is used (mmc_test)
  also.
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

There are two checks that need to be made when determining whether a
card is removable. A host controller may set MMC_CAP_NONREMOVABLE if the
controller does not support removing cards (e.g. eMMC), in which case
the card is physically non-removable. Also the 'mmc_assume_removable'
module parameter can be configured at module load time, in which case
the card may be logically non-removable.

A helper function keeps the logic in one place so that code always
checks both conditions.

Because this new function is likely to be called from modules we now
need to export the mmc_assume_removable symbol.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Tested-by: NJaehoon Chung <jh80.chung@samsung.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

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: NAdrian Hunter <adrian.hunter@nokia.com>
Acked-by: NJens 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some people run general-purpose distribution kernels on netbooks with
a card that is physically non-removable or logically non-removable
(e.g. used for /home) and cannot be cleanly unmounted during suspend.
Add a module parameter to set whether cards are assumed removable or
non-removable, with the default set by CONFIG_MMC_UNSAFE_RESUME.

In general, it is not possible to tell whether a card present in an MMC
slot after resume is the same that was there before suspend.  So there are
two possible behaviours, each of which will cause data loss in some cases:

CONFIG_MMC_UNSAFE_RESUME=n (default): Cards are assumed to be removed
during suspend.  Any filesystem on them must be unmounted before suspend;
otherwise, buffered writes will be lost.

CONFIG_MMC_UNSAFE_RESUME=y: Cards are assumed to remain present during
suspend.  They must not be swapped during suspend; otherwise, buffered
writes will be flushed to the wrong card.

Currently the choice is made at compile time and this allows that to be
overridden at module load time.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Cc: Wouter van Heyst <larstiq@larstiq.dyndns.org>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Especially for SDIO drivers which may have special conditions/errors to
report, it is a good thing to relay the returned error code back to upper
layers.

This also allows for the rationalization of the resume path where code to
"remove" a no-longer-existing or replaced card was duplicated into the
MMC, SD and SDIO bus drivers.

In the SDIO case, if a function suspend method returns an error, then all
previously suspended functions are resumed and the error returned.  An
exception is made for -ENOSYS which the core interprets as "we don't
support suspend so just kick the card out for suspend and return success".

When resuming SDIO cards, the core code only validates the manufacturer
and product IDs to make sure the same kind of card is still present before
invoking functions resume methods.  It's the function driver's
responsibility to perform further tests to confirm that the actual same
card is present (same MAC address, etc.) and return an error otherwise.
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the new MMC command SLEEP_AWAKE.
Signed-off-by: NJarkko Lavinen <jarkko.lavinen@nokia.com>
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Acked-by: NMatt 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus 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: NAdrian Hunter <adrian.hunter@nokia.com>
Acked-by: NMatt 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For each card successfully added to the bus, create a subdirectory under
the host's debugfs root with information about the card.

At the moment, only a single file is added to the card directory for
all cards: "state". It reflects the "state" field in struct mmc_card,
indicating whether the card is present, readonly, etc.

For MMC and SD cards (not SDIO), another file is added: "status".
Reading this file will ask the card about its current status and
return it. This can be useful if the card just refuses to respond to
any commands, which might indicate that the card state is not what the
MMC core thinks it is (due to a missing stop command, for example.)
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: NPierre 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: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>