When plugging a specific micro SD card at MMC socket of a custom i.MX28 board,
we get the following kernel warning:

WARNING: CPU: 0 PID: 30 at drivers/mmc/host/mxs-mmc.c:342 mxs_mmc_start_cmd+0x34c/0x378()
Modules linked in:
CPU: 0 PID: 30 Comm: kworker/u2:1 Not tainted 3.14.0-rc5 #8
Workqueue: kmmcd mmc_rescan
[<c0015420>] (unwind_backtrace) from [<c0012cb0>] (show_stack+0x10/0x14)
[<c0012cb0>] (show_stack) from [<c001daf8>] (warn_slowpath_common+0x6c/0x8c)
[<c001daf8>] (warn_slowpath_common) from [<c001db34>] (warn_slowpath_null+0x1c/0x24)
[<c001db34>] (warn_slowpath_null) from [<c0349478>] (mxs_mmc_start_cmd+0x34c/0x378)
[<c0349478>] (mxs_mmc_start_cmd) from [<c0338fa0>] (mmc_start_request+0xc4/0xf4)
[<c0338fa0>] (mmc_start_request) from [<c03390b4>] (mmc_wait_for_req+0x50/0x164)
[<c03390b4>] (mmc_wait_for_req) from [<c03405b8>] (mmc_app_send_scr+0x158/0x1c8)
[<c03405b8>] (mmc_app_send_scr) from [<c033ee1c>] (mmc_sd_setup_card+0x80/0x3c8)
[<c033ee1c>] (mmc_sd_setup_card) from [<c033f788>] (mmc_sd_init_card+0x124/0x66c)
[<c033f788>] (mmc_sd_init_card) from [<c033fd7c>] (mmc_attach_sd+0xac/0x174)
[<c033fd7c>] (mmc_attach_sd) from [<c033a658>] (mmc_rescan+0x25c/0x2d8)
[<c033a658>] (mmc_rescan) from [<c003597c>] (process_one_work+0x1b4/0x4ec)
[<c003597c>] (process_one_work) from [<c0035de4>] (worker_thread+0x130/0x464)
[<c0035de4>] (worker_thread) from [<c003c824>] (kthread+0xb4/0xd0)
[<c003c824>] (kthread) from [<c000f420>] (ret_from_fork+0x14/0x34)

The error is due to an invalid value in CSD register of a specific 2GB
micro SD card. The CSD version of this card is 1.0 but the TACC field
has the invalid value 0.

cid:0000005553442020000000000000583f
csd:00000032535a83bfedb7ffbf1680003f
date:08/2005
erase_size:512
fwrev:0x0
hwrev:0x0
manfid:0x000000
name:USD
oemid:0x0000
preferred_erase_size:4194304
scr:0225000000000000
serial:0x00000000
type:SD

Since the kernel is making use of this TACC field to calculate the SD
card timeout, an invalid value 0 leads to a warning at
mxs_ns_to_ssp_ticks() and later the following misleading error message
appears in a loop:

mxs-mmc 80010000.ssp: card claims to support voltages below defined range
mxs-mmc 80010000.ssp: no support for card's volts
mmc0: error -22 whilst initialising MMC card

This error is only found on this 2GB SD card on mxs platform.
On x86 this card works without any problems.

The following patch based on the work of Peter Chan and Otavio Salvador.
It catches the case that the determined timeout is still 0 and sets it
to a valid value.

Successful tested on a i.MX28 board.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

This change removes the callback from atomic context which it doesn't
need to be in, and puts it in line with the debounced rescan.

This code is based on these e-mail threads with Christian Daudt:

  https://lkml.org/lkml/2013/8/19/539
  https://lkml.org/lkml/2014/3/19/79Signed-off-by: NMarkus Mayer <markus.mayer@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Add functions to request a CD GPIO using the GPIO descriptor API.
Note that the new request function is paired with mmc_gpiod_free_cd()
not mmc_gpio_free_cd().  Note also that it must be called prior to
mmc_add_host() otherwise the caller must also call
mmc_gpiod_request_cd_irq().
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Instead of handle specific adaptations, releated to certain switch
operations, inside __mmc_switch, push this to be handled by the caller
instead.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

To better reflect that the cmd_timeout_ms is directly related to the
busy detection timeout, let's rename it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Rename host->max_discard_to to host->max_busy_timeout, to reflect that
it tells the mmc core layer about the maximum supported busy detection
timeout by the host.

This timeout is at the moment only applicable to erase/trim/discard
commands. By the renaming we provide the option of make use of it for
other commands that cares about busy detection. In other words, those
commands that wants an R1B response, like for example the mmc switch
command.

Do note that the max_busy_timeout is supposed to be specified only by
hosts supporting MMC_CAP_WAIT_WHILE_BUSY.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

There are no reason to why the use of a non-volatile internal eMMC
cache should be controlled by a host cap. Instead let's just enable it
if the eMMC card supports it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NChris Ball <chris@printf.net>

Earlier we disabled the cache during suspend, which meant a flush was
internally at the eMMC performed as well.

To simplify code we can make use of the mmc_flush_cache(), during mmc
suspend, which makes the mmc_cache_ctrl() redundant so then we can
remove it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NChris Ball <chris@printf.net>

Due to the removal of the Kconfig option MMC_UNSAFE_RESUME, several
validations of a present bus_ops callback became redundant. Let's
remove these.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Invoking system suspend or shutdown without using the Kconfig option
MMC_UNSAFE_RESUME, did trigger an ungraceful power cut of the card.

To improve the situation, change the behavior to always make use of the
available bus_ops callbacks that handles system suspend and shutdown
properly.

By changing the behavior MMC_UNSAFE_RESUME becomes redundant, so lets's
remove it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Non removable cards are always present, so do not call get_cd for them.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

The are no more users of the deprecated mmc_suspend|resume_host API,
so let's remove it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

We want to give user space provision to fully consume a card
insert/remove event, when the event was caused by a wakeup irq.

By signaling the wakeup event for a time of 5 s for devices configured
as wakeup capable, we likely will be prevent a sleep long enough to let
user space consume the event.

To enable this feature, host drivers must thus configure their devices
as wakeup capable.

This is a reworked implementation of the old wakelocks for the mmc
subsystem, originally authored by Colin Cross and San Mehat for the
Android kernel. Zoran Markovic shall also be given cred for recently
re-trying to upstream this feature.

Cc: San Mehat <san@google.com>
Cc: Colin Cross <ccross@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Zoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NZoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Since mmc_select_voltage now only gets called from the attach sequence,
it makes sense to move the out of spec validations of the card ocr into
this function.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

According to eMMC/SD/SDIO specs, the VDD (VCC) voltage level must be
maintained during the initialization sequence. If we want/need to tune
the voltage level, a complete power cycle of the card must be executed.

Most host drivers conforms to the specifications by only allowing to
change VDD voltage level at the MMC_POWER_UP state, but some also cares
about MMC_POWER_ON state, which they should'nt. This patch will not
break those drivers, but they could clean up code to better reflect
what is expected from the protocol layer.

A big re-work of the mmc_select_voltage function is done to only change
VDD voltage level if the host supports MMC_CAP2_FULL_PWR_CYCLE.
Otherwise only validation of the host and card ocr mask will be done.

A very nice side-effect of this patch is that we now don't need to
reset the negotiated ocr mask at the mmc_power_off function, since now
it will actually reflect the present voltage level, which safely can be
used at the next power up and re-initialization. Moreover, we then only
need to execute mmc_select_voltage from the attach sequence.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

The negotiated ocr mask is directly related to the card. Once a card
gets removed, the mask shall be dropped. By moving the cache of the ocr
mask from the host struct to the card struct we have accomplished this.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.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>

Some switch operations like poweroff notify, shall according to the
spec not be followed by any other new commands. For these cases and
when the host does'nt support MMC_CAP_WAIT_WHILE_BUSY, we must not
send status commands to poll for busy detection. Instead wait for
the stated timeout from the EXT_CSD before completing the request.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

cscope says there are no callers for mmc_try_claim_host in the kernel.
No reason to keep it.
Signed-off-by: NGrant Grundler <grundler@chromium.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Add function to support getting voltage from device-tree.
If voltage-range is specified in device-tree node, this function
will parse it and return the available voltage mask.
Signed-off-by: NHaijun Zhang <haijun.zhang@freescale.com>
Acked-by: NAnton Vorontsov <anton@enomsg.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Use regulator_get_optional() to tell the core that requests for the vmmcq
regulator can fail in a real system.
Signed-off-by: NMark Brown <broonie@linaro.org>
Acked-by: NChris Ball <cjb@laptop.org>

The host should be responsible to suspend|resume the host and not the
card. This patch changes this behaviour, by moving the responsiblity
to the mmc bus instead which already holds the card device.

The exported functions mmc_suspend|resume_host are now to be considered
as depcrecated. Once all host drivers moves away from using them, we
can remove them. As of now, a successful error code is always returned.
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>

By moving code from the mmc_suspend|resume_host down into each
.suspend|resume bus_ops callback, we get a more flexible solution.

Some nice side effects are that we get a better understanding of each
bus_ops suspend|resume sequence and the common code don't have to take
care of specific corner cases, especially for the SDIO case.
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>

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>

For every bus_ops type the .remove callback always exist, thus there
are no need to check the existence of it, before we decide to call it.
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>

Once the mmc blkdevice is being probed, runtime pm will be enabled.
By using runtime autosuspend, the power save operations can be done
when request inactivity occurs for a certain time. Right now the
selected timeout value is set to 3 s. Obviously this value will likely
need to be configurable somehow since it needs to be trimmed depending
on the power save algorithm.

For SD-combo cards, we are still leaving the enablement of runtime PM
to the SDIO init sequence since it depends on the capabilities of the
SDIO func driver.

Moreover, when the blk device is being suspended, we make sure the device
will be runtime resumed. The reason for doing this is that we want the
host suspend sequence to be unaware of any runtime power save operations
done for the card in this phase. Thus it can just handle the suspend as
the card is fully powered from a runtime perspective.

Finally, this patch prepares to make it possible to move BKOPS handling
into the runtime callbacks for the mmc bus_ops. Thus IDLE BKOPS can be
accomplished.
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>

Move mmc suspend specific operations to be executed from the .suspend
callback in the mmc bus_ops. This simplifies the mmc_suspend_host
function which is supposed to handle nothing but common suspend tasks.

Since eMMC can be considered non-removable there are no need to check
for ongoing bkops at PM_SUSPEND_PREPARE notification so remove it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

The sanitize support is added as a user-app ioctl call, and
was removed from the block-device request, since its purpose is
to be invoked not via File-System but by a user.

This feature deletes the unmap memory region of the eMMC card,
by writing to a specific register in the EXT_CSD.

unmap region is the memory region that was previously deleted
(by erase, trim or discard operation).

In order to avoid timeout when sanitizing large-scale cards,
the timeout for sanitize operation is 240 seconds.
Signed-off-by: NYaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: NMaya Erez <merez@codeaurora.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Previously the MMC_CAP2_DETECT_ON_ERR was invented for detecting
slow card removal. In was never a realy good solution and a proper
fix has been merged using gpio debouncing instead. We remove this
cap in this patch.

Although when using polling card detect mode, the code invented for
MMC_CAP2_DETECT_ON_ERR is re-used to complete card removal in an
earlier phase. There are no need waiting for the polling timeout to
elapse in this case.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NKevin Liu <kliu5@marvell.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

Use preferable function name which implies using a pseudo-random
number generator.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Chris Ball <cjb@laptop.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add MMC_CAP2_NO_PRESCAN_POWERUP to sdhci-pci.c also, use mmc_power_off()
for MMC_CAP2_NO_PRESCAN_POWERUP.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
[cjb: previously applied v1 of this patch instead of v4]
Signed-off-by: NChris Ball <cjb@laptop.org>

Commit fa550189 introduced a performance
regression by adding mmc_power_up() to mmc_start_host().  mmc_power_up()
is not necessary to host controller initialization, it is part of card
initialization and is performed anyway asynchronously.

This patch allows a driver to leave the power up in asynchronous code
(as it was before).

On my current target platform this reduces driver initialization from:

[    1.313220] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 102008 usecs

to this:

[    1.217209] initcall sdhci_acpi_driver_init+0x0/0x12 returned 0 after 8331 usecs
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

This reverts commit 3500ed90.

The reverted patch caused a significant performance regression when
booting with the root file system on eMMC.

Before the patch:

[    1.625623] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.

After the patch:

[    1.935851] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.

That was an addition of 310 ms which is a 19% performance degradation.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

MMC hosts are added asynchronously. We need to wait until detect returns to
avoid failed root filesystem mounts.

VFS: Cannot open root device "mmcblk0p1" or unknown-block(0,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
mmc0: host does not support reading read-only switch. assuming write-enable.
1f00             256 mtdblock0  (driver?)
1f01             256 mtdblock1  (driver?)
1f02            2560 mtdblock2 mmc0: new SDHC card at address b368
 (driver?)
1f03           29696 mtdblock3  (driver?)
1f04           16384 mtdblock4 mmcblk0: mmc0:b368 USD   3.72 GiB
 (driver?)
 mmcblk0: p1
b300         3910656 mmcblk0  driver: mmcblk
  b301         3906560 mmcblk0p1 00000000-01
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Signed-off-by: NSergey Yanovich <ynvich@gmail.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

Function _mmc_detect_card_removed will be called to know whether
the card is still present when host->bus_ops->detect is called.
In current code, the return value of this function generally only
depend on the result of sending cmd13 to card, which may not safe
for card with detection support like slot gpio detection.
Because the communication status between host and card may out of
sync with the detect status if remove the card slowly or hands shake
during the process. The direct reason is the async between card
detect switch and card/slot pad contaction in hardware, which is
defined by spec.

The spec define card insert/remove sequence as below (both standard size
SD card and MicroSD card have the same sequence):
"Part 1 Standard Size SD Card Mechanical Addendum Ver4.00 Final,
Appendix C: Card Detection Switch" (Take normally open type as example)
a)SD card insertion sequence:
  The card detection switch should be turned on after all SD card
  contact pads are connected to the host connector contact pads.
b)SD removal sequence:
  The card detection switch should be turned off when the SD card
  is just going to be removed and before any SD card contact pad is
  disconnected from the host connector contact pad.

Below is the sequence when this issue occur (Take slot gpio detection
as example and remove the card slowly during the process):
1. gpio level changed and card detect interrupt triggered.
2. mmc_rescan was launched.
3. the card pads were still contacted with the slot pads because of slow
   removal. So _mmc_detect_card_removed and mmc_rescan think card was
   still present (cmd13 succeed).
4. card pads were discontacted from the card slot pads.
So the card was actually removed finally but the card removal event
has been missed by system.
The interval length between step 1 and step 4 depends on the
card removal speed. If it's longer than the detect work schedule
delay which is 200ms, this issue will likely happen.

This patch add the card detect status check in function
_mmc_detect_card_removed if cmd13 check succeed and host->ops->get_cd
provided. If get_cd detect no card present then schedule another detect
work 200ms later.
Signed-off-by: NKevin Liu <kliu5@marvell.com>
Tested-by: NJohan Rudholm <johan.rudholm@stericsson.com>
Reviewed-by: NPhilip Rakity <prakity@nvidia.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

mmc_regulator_set_ocr() depends on the ability of regulator to change the
voltage value. When regulator cannot change its voltage output, some code
is skipped to avoid reporting false errors on some boards, which use MMC
hosts with fixed regulators (e.g. Samsung Goni and UniversalC210 boards).

This patch replaces a hacky workaround based on regulator_count_voltages()
value with the correct call to recently introduced
regulator_can_change_voltage() function in regulators core.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

This patch fixes incorrect indentation.  (Just code cleanup)
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>