Allow to specify in the device-tree that no physical write-protect signal
is connected to a particular instance of a MMC controller. Setting the
property will cause the core will assume that the SD card is always
read-write.

The name for the new property is 'disable-wp' and was chosen based on the
property with the same function from the Synopsys designware mobile storage
host controller DT bindings specification.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
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>

Currently, there is core support for tuning during
initialization. There can also be a need to re-tune
periodically (e.g. sdhci) or to re-tune after the
host controller is powered off (e.g. after PM
runtime suspend / resume) or to re-tune in response
to CRC errors.

The main requirements for re-tuning are:
  - ability to enable / disable re-tuning
  - ability to flag that re-tuning is needed
  - ability to re-tune before any request
  - ability to hold off re-tuning if the card is busy
  - ability to hold off re-tuning if re-tuning is in
  progress
  - ability to run a re-tuning timer

To support those requirements 7 members are added to struct
mmc_host:

  unsigned int		can_retune:1;	/* re-tuning can be used */
  unsigned int		doing_retune:1;	/* re-tuning in progress */
  unsigned int		retune_now:1;   /* do re-tuning at next req */
  int			need_retune;	/* re-tuning is needed */
  int			hold_retune;	/* hold off re-tuning */
  unsigned int		retune_period;  /* re-tuning period in secs */
  struct timer_list	retune_timer;	/* for periodic re-tuning */

need_retune is an integer so it can be set without needing
synchronization. hold_retune is a integer to allow nesting.

Various simple functions are provided to set / clear those
variables.

Subsequent patches take those functions into use.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

System on chip designs may specify a specific MMC power sequence. To
successfully detect an (e)MMC/SD/SDIO card, that power sequence must
be followed while initializing the card.

To be able to handle these SOC specific power sequences, let's add a
MMC power sequence interface. It provides the following functions to
help the mmc core to deal with these power sequences.

mmc_pwrseq_alloc() - Invoked from mmc_of_parse(), to initialize data.
mmc_pwrseq_pre_power_on()- Invoked in the beginning of mmc_power_up().
mmc_pwrseq_post_power_on()- Invoked at the end in mmc_power_up().
mmc_pwrseq_power_off()- Invoked from mmc_power_off().
mmc_pwrseq_free() - Invoked from mmc_free_host(), to free data.

Each MMC power sequence provider will be responsible to implement a set
of callbacks. These callbacks mirrors the functions above.

This patch adds the skeleton, following patches will extend the core of
the MMC power sequence and add support for a specific simple MMC power
sequence.

Do note, since the mmc_pwrseq_alloc() is invoked from mmc_of_parse(),
host drivers needs to make use of this API to enable the support for
MMC power sequences. Moreover the MMC power sequence support depends on
CONFIG_OF.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>

By moving the allocation of the slot-gpio data into mmc_alloc_host(),
we can remove the slot-gpio internal calls to mmc_gpio_alloc().

This means mmc_gpio_alloc() has now only one caller left, which
consequence allow us to simplify and remove some of the slot-gpio code.

Additionally, this makes the slot-gpio mutex redundant, so let's remove
it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

To be consistent when freeing data, let's move the idr_remove() call
from mmc_free_host() into the ->dev_release() callback for the class
device.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Instead of just printing an error when mmc_of_parse() fails to request
CD/WP GPIO pins, let's propagate all errors, except for -ENOENT.
Earlier only -EPROBE_DEFER was handled correctly.

As a side effect of this change and by relying on host drivers to
handle the errors during ->probe(), we don't need to free any data in
the error path.

This also means we are actually fixing a bug, since we remove the call
to mmc_gpio_free_cd() which wasn't the correct function to invoke to
handle cleanup. Instead that should have been mmc_gpiod_free_cd().
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Since commit 89168b48 ("mmc: core: restore detect line inversion
semantics"), the SD card on i.MX28 (and possibly other) devices isn't
detected and booting stops at:

[    4.120617] Waiting for root device /dev/mmcblk0p3...

This is caused by the MMC_CAP2_CD_ACTIVE_HIGH flag being set incorrectly
when the host controller doesn't use a GPIO for card detection (but
instead uses a dedicated pin). In this case mmc_gpiod_request_cd() will
return before assigning to the gpio_invert variable, leaving the
variable uninitialized. The variable then gets used to set the flag.
This patch fixes the issue by making sure gpio_invert is set to false
when a GPIO isn't used. After this patch, i.MX28 boots fine.

The MMC_CAP2_RO_ACTIVE_HIGH (write protect) flag is also set incorrectly
for the exact same reason (it uses the same uninitialized variable), so
this patch fixes that too.

Fixes: 89168b48 ("mmc: core: restore detect line inversion semantics")
Reported-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NKristina Martšenko <kristina.martsenko@gmail.com>
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

commit 98e90de9
"mmc: host: switch OF parser to use gpio descriptors"
switched the semantic behaviour of card detect and read
only flags such that the inversion capability flag would
only be set if inversion was explicitly specified in the
device tree, in the hopes that no-one was using double
inversion.

It turns out that the XOR:ing between the explicit
inversion was indeed in use, so we need to restore the
old semantics where both ways of inversion are checked
and the end result XOR:ed.
Reported-by: NJavier Martinez Canillas <javier@dowhile0.org>
Tested-by: NJavier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

This switches the central MMC OF parser to use gpio descriptors
instead of grabbing GPIOs explicitly from the device tree.
This strips out an unecessary use of the integer-based GPIO
API that we want to get rid of, cuts down on code as the
gpio descriptor code will handle active low flags.
Acked-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Some eMMC and SD cards implement a DSR register that allows to tune
raise/fall times and drive strength of the CMD and DATA outputs.
The values to use depend on the card in use and the host.
It might be needed to reduce the drive strength to prevent voltage peaks
above the host's specification.

Implement a 'dsr' devicetree property that allows to specify the value
to set the DSR to. For non-dt setups the new members of mmc_host can be
set by board code.

This patch was initially authored by Sascha Hauer. It contains
improvements authored by Markus Niebel and Uwe Kleine-König.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMarkus Niebel <Markus.Niebel@tq-group.com>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Provide the option to configure these speed modes per host,
for those host driver's that can't distinguish this in runtime.
Specially, if host can support HS400, it means that host can also
support HS200.
Signed-off-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Provide the option to configure these speed modes per host, for those
host driver's that can't distinguish this in runtime.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Provide the option to configure these speed modes per host, for those
host driver's that can't distinguish this in runtime.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NChris Ball <chris@printf.net>

Provide the option to configure these speed modes per host, for those
host driver's that can't distinguish this in runtime.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NChris Ball <chris@printf.net>

Add a debounce parameter to the mmc_gpio_request_cd() function that
enables GPIO debouncing when set to a non-zero value. This can be used
by MMC host drivers to enable debouncing on the card detect signal.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

The DT-binding for MMC_CAP2_FULL_PWR_CYCLE, is used to indicate whether
it is possible to perform a full power cycle of the card.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

In addition to just logging errors encountered during DT parsing or
allocating GPIO slots for CD/WP, mmc_of_parse() now returns with an error.

In particular, this is needed if the GPIO allocation may return
EPROBE_DEFER.
Signed-off-by: NSimon Baatz <gmbnomis@gmail.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Convert to the much saner new idr interface.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Chris Ball <cjb@laptop.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many MMC capability flags are platform-dependent and are traditionally set
in platform data. With DT often each such capability requires a special
binding. Add bindings for MMC_CAP_SD_HIGHSPEED, MMC_CAP_MMC_HIGHSPEED,
MMC_CAP_POWER_OFF_CARD and MMC_CAP_SDIO_IRQ capabilities. Also add code to
DT parser to look up "keep-power-in-suspend" and "enable-sdio-wakeup"
bindings and set MMC_PM_KEEP_POWER and MMC_PM_WAKE_SDIO_IRQ respectively,
if found.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

MMC defines a number of standard DT bindings. Having each driver parse
them individually adds code redundancy and is error prone. Provide a
standard function to unify the parsing. After all drivers are converted
to using it instead of their own parsers, this function can be integrated
into mmc_alloc_host().
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

system_nrt[_freezable]_wq are now spurious.  Mark them deprecated and
convert all users to system[_freezable]_wq.

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant, so there's no reason to use system_nrt[_freezable]_wq.
Please use system[_freezable]_wq instead.

This patch doesn't make any functional difference.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-By: NLai Jiangshan <laijs@cn.fujitsu.com>

Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>

Currently mmc host drivers have to decide whether to enable card
detection before calling mmc_add_host() -- in which case a card
insertion event can arrive before the host has been completely
initialised -- or after mmc_add_host(), in which case the initial
card detection can be problematic.

This patch adds an explicit indication of when card detection should
not be carried out. With it in place enabling card detection before
calling mmc_add_host() should be safe. Similarly, disabling it again
after calling mmc_remove_host() will avoid any races.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

This prepares for the addition of further slot functions.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

struct mmc_host::hotplug is becoming a generic hook for slot functions.
Rename it accordingly.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

Most parts of the enable / disable API are no longer used and
can be removed.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Tested-by: NVenkatraman S <svenkatr@ti.com>
Tested-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

A recent commit "mmc: core: Use delayed work in clock gating framework"
(597dd9d7) introduced a default 200ms delay before clock gating
actually takes place.  This means that every time an MMC interface
becomes idle it first stays on for 200ms before gating its clock. This
leads to increased power consumption and is therefore a clear regression.
This patch restores the original behaviour by setting the default delay
to 0. Users prioritising throughput over power efficiency can still
modify the delay via sysfs.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

c31b50e (mmc: core: Use delayed work in clock gating framework,
2011-11-14) missed a few things during review:

 o A useless pr_info()

 o milliseconds was written as two words

 o The sysfs file had units in its output

Fix all three problems.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Current clock gating framework disables the MCI clock as soon as the
request is completed and enables it when a request arrives. This aggressive
clock gating framework, when enabled, cause following issues:

When there are back-to-back requests from the Queue layer, we unnecessarily
end up disabling and enabling the clocks between these requests since 8MCLK
clock cycles is a very short duration compared to the time delay between
back to back requests reaching the MMC layer. This overhead can effect the
overall performance depending on how long the clock enable and disable
calls take which is platform dependent. For example on some platforms we
can have clock control not on the local processor, but on a different
subsystem and the time taken to perform the clock enable/disable can add
significant overhead.

Also if the host controller driver decides to disable the host clock too
when mmc_set_ios function is called with ios.clock=0, it adds additional
delay and it is highly possible that the next request had already arrived
and unnecessarily blocked in enabling the clocks. This is seen frequently
when the processor is executing at high speeds and in multi-core platforms
thus reduces the overall throughput compared to if clock gating is
disabled.

Fix this by delaying turning off the clocks by posting request on
delayed workqueue. Also cancel the unscheduled pending work, if any,
when there is access to card.

sysfs entry is provided to tune the delay as needed, default
value set to 200ms.
Signed-off-by: NSujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

When SDIO runtime PM was originally introduced, we immediately faced
two regressions with two different chipsets, and in response decided
not to enable it by default.

With the recent work on the 8686 we hoped we found all the gotchas,
so 08da834a did make sense (at least experimentally).

Unfortunately we now see that some setups out there still refuse to
work when SDIO runtime PM is enabled by default (see
http://www.spinics.net/lists/linux-mmc/msg11161.html), and obviously
we can't live with these kind of regressions.

This reverts commit 08da834a.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Cc: Daniel Drake <dsd@laptop.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

These two basic defines were everywhere, simply because module.h
was also everywhere.   But we are cleaning up the latter.  So make
the exporters actually call out their need for the include.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Now that we have improved the runtime power management powerup/powerdown
code, we believe that MMC_CAP_POWER_OFF_CARD is no longer necessary:
runtime PM should now work everywhere.

The only hard evidence for introducing MMC_CAP_POWER_OFF_CARD was the
Marvell sd8686 wifi chip, which was believed to require external gpio
manipulation which wasn't supported by some boards.

After further investigation it was realized (and confirmed by Marvell
folks) that sd8686 requirements can be fulfilled by changing the reset
sequence itself, even if no external gpio is manipulated.

For further information, see the following thread:
http://www.mail-archive.com/linux-mmc@vger.kernel.org/msg04289.html

Enable this trivially for a release or two. If no problems are reported,
we will follow up with a more extensive patch to remove this flag
altogether. If problems are reported, we can look at whitelist/blacklist
possibilities as before.
Signed-off-by: NDaniel Drake <dsd@laptop.org>
Acked-by: NOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

The default multithread workqueue can cause the same work to be executed
concurrently on a different CPUs. This isn't really suitable for clock
gating as it might already gated the clock and gating it twice results both
host->clk_old and host->ios.clock to be set to 0.

To prevent this from happening we use system_nrt_wq instead.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Tested-by: NChris Ball <cjb@laptop.org>
Cc: <stable@kernel.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

As per suggestion by Linus Walleij:

  > If you think the names of the functions are confusing then
  > you may rename them, say like this:
  >
  > mmc_host_clk_ungate() -> mmc_host_clk_hold()
  > mmc_host_clk_gate() -> mmc_host_clk_release()
  >
  > Which would make the usecases more clear

(This is CC'd to stable@ because the next two patches, which fix
observable races, depend on it.)
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: <stable@kernel.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

led_trigger_register_simple() allocates memory which must not be leaked
in the error-path of mmc_add_host. Move it past the only error-check in
the function.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NChris Ball <cjb@laptop.org>

This reverts commit 26fc8775, which has
been reported to cause boot/resume-time crashes for some users:

https://bbs.archlinux.org/viewtopic.php?id=118751.
Signed-off-by: NChris Ball <cjb@laptop.org>
Cc: <stable@kernel.org>

Currently there is a race in the MMC core between a card-detect
rescan work and the clock-gating work, scheduled from a command
completion. Fix it by removing the dedicated clock-gating mutex
and using the MMC standard locking mechanism instead.
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <damm@opensource.se>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Cc: <stable@kernel.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Some sdio card are not following sdio standard, and do not work
when the sdio bus's clock is gated.

To keep functionnality for all legacy driver, we turn this quirk on
for every sdio card.
Drivers needs to disable the quirk manually when someone verifies that
their supported card works with clock gating.
Signed-off-by: NPierre Tardy <tardyp@gmail.com>
Acked-by: NOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

Since we make sure the clock is enabled in the mmc_host_clk_exit()
function we should expect a reference counter of 1, not 0.
Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
Tested-by: NChris Ball <cjb@laptop.org>
Signed-off-by: NChris Ball <cjb@laptop.org>