In the MMC subsystem, we see such initializers that only clears the
first member explicitly.

For example,

  struct mmc_request mrq = {NULL};

sets the first member (.sbc) to NULL explicitly.  However, this is
an unstable form because we may insert a non-pointer member at the
top of the struct mmc_request in the future. (if we do so, the
compiler will spit warnings.)

So, using a designated initializer is preferred coding style.  The
expression above is equivalent to:

  struct mmc_request mrq = { .sbc = NULL };

Of course, this does not express our intention.  We want to fill
all struct members with zeros.  Please note struct members are
implicitly zero-cleared unless otherwise specified in the initializer.

After all, the most reasonable (and stable) form is:

  struct mmc_request mrq = {};

Do likewise for mmc_command, mmc_data as well.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Regressions for not being able to detect an eMMC HS DDR mode card has been
reported for the sdhci-esdhc-imx driver, but potentially other sdhci
variants may suffer from the similar problem.

The commit e173f891 ("mmc: core: Update CMD13 polling policy when
switch to HS DDR mode"), is causing the problem. It seems that change moved
one step to far, regarding changing the host's timing before polling for a
busy card.

To fix this, let's move back to the behaviour when the host's timing is
updated after the polling, but before the switch status is fetched and
validated.

In cases when polling with CMD13, we keep validating the switch status at
each attempt. However, to align with the other card busy detections
mechanism, let's fetch and validate the switch status also after the host's
timing is updated.
Reported-by: NClemens Gruber <clemens.gruber@pqgruber.com>
Reported-by: NGary Bisson <gary.bisson@boundarydevices.com>
Fixes: e173f891 ("mmc: core: Update CMD13 polling policy when switch..")
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Dong Aisheng <aisheng.dong@nxp.com>
Cc: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NClemens Gruber <clemens.gruber@pqgruber.com>
Tested-by: NJagan Teki <jagan@amarulasolutions.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Tested-by: NHaibo Chen <haibo.chen@nxp.com>
Reviewed-by: NDong Aisheng <aisheng.dong@nxp.com>

If a tuning command times out, the card could still be processing it, which
will cause problems for recovery. The eMMC specification says that CMD12
can be used to stop CMD21, so add a function that does that.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The JEDEC specification indicates CMD13 can be used after a HS200 switch
to check for errors. However in practice some boards experience CRC errors
in the CMD13 response. Consequently, for HS200, CRC errors are not a
reliable way to know the switch failed. If there really is a problem, we
would expect tuning will fail and the result ends up the same. So change
the error condition to ignore CRC errors in that case.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

BUG_ONs doesn't help anything except for stop the system from
running. If it occurs, it implies we should deploy proper error
handling for that. So this patch is gonna discard these meaningless
BUG_ONs and deploy error handling if needed.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

In cases when a speed mode change is requested for mmc cards, a CMD6 is
sent by calling __mmc_switch() during the card initialization. The CMD6
leads to the card entering a busy period. When that is completed, the host
must parse the CMD6 status to find out whether the change of the speed mode
succeeded.

To enable the mmc core to poll the card by using CMD13 to find out when the
busy period is completed, it's reasonable to make sure polling is done by
having the mmc host and the mmc card, being configured to operate at the
same selected bus speed timing.

Therefore, let's extend __mmc_switch() to take yet another parameter, which
allow its callers to update the bus speed timing of the mmc host. In this
way, __mmc_switch() also becomes capable of reading and validating the CMD6
status by sending a CMD13, in cases when that's desired.

If __mmc_switch() encounters a failure, we make sure to restores the old
bus speed timing for the mmc host, before propagating the error code.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>

According to the JEDEC specification, the SWITCH_ERROR bit in the device
status from a R1 response, is an error bit which may be cleared as soon as
the response that reports the error is sent.

When polling with CMD13 to find out when the card stops signaling busy
after a CMD6 has been sent, we currently parse only the last CMD13 response
for the SWITCH_ERROR bit. Consequentially we could loose important
information about the card.

In worst case if the card stops signaling busy within the allowed timeout,
we could end up believing that the CMD6 command completed successfully,
when in fact it didn't.

To improve the behaviour, let's parse each CMD13 response to see if the
SWITCH_ERROR bit is set in the device status. In such case, we abort the
polling loop and report the error.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>

The ignore_crc parameter/variable name is used at a couple of places in the
mmc core. Let's rename it to retry_crc_err to reflect its new purpose.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>

There are only one users left which calls __mmc_send_status(). Moreover,
the ignore_crc parameter isn't being used, so let's just remove these
redundant parts.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>

After a CMD6 command has been sent, the __mmc_switch() function might be
advised to poll the card for busy by using CMD13 and also by ignoring CRC
errors.

In the case of ignoring CRC errors, the mmc core tells the mmc host to also
ignore these errors via masking the MMC_RSP_CRC response flag. This seems
wrong, as it leads to that the mmc host could propagate an unreliable
response, instead of a proper error code.

What we really want, is not to ignore CRC errors but instead retry the
polling attempt. So, let's change this by treating a CRC error as the card
is still being busy and thus continue to run the polling loop.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>

When polling for busy after sending a MMC_SWITCH command, both the optional
->card_busy() callback and CMD13 are being used in conjunction.

This doesn't make sense. Instead it's more reasonable to rely solely on the
->card_busy() callback when it exists. Let's change that and instead use
the CMD13 as a fall-back. In this way we avoid sending CMD13, unless it's
really needed.

Within this context, let's also take the opportunity to make some
additional clean-ups and clarifications to the related code.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Tested-by: NJaehoon Chung <jh80.chung@samsung.com>

In yet another step of cleaning up __mmc_switch(), let's factor out the
code that deals with card busy polling.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Tested-by: NJaehoon Chung <jh80.chung@samsung.com>

The __mmc_switch() deserves a clean-up. In this step, let's move some code
outside of the do-while loop, which deal deals with the card busy polling.

This change simplifies the code in that sense that it becomes easier to follow
what is being executed during card busy polling, but it also gives a better
understanding for when polling isn't done.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Tested-by: NJaehoon Chung <jh80.chung@samsung.com>

Following changes needs mmc_switch_status() to be available both from mmc.c
and mmc_ops.c. Allow that by moving its implementation to mmc_ops.c and
make it available via mmc_ops.h.

Moving mmc_switch_status() to mmc_ops.c, also enables us to turn
mmc_switch_status_error() into static function. So let's take the
opportunity to change this as well.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>
Tested-by: NJaehoon Chung <jh80.chung@samsung.com>

with CONFIG_HZ=100, the precision of jiffies is 10ms, and the
generic_cmd6_time of some card is also 10ms. then, may be current
time is only 5ms, but already timed out caused by jiffies precision.
Signed-off-by: NChaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Some MMC hosts do not support MMC_CAP_WAIT_WHILE_BUSY, but implements the
->card_busy() callback. In such cases, extend __mmc_switch() to use this
method to check card status after switch command.
Signed-off-by: NChaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Variable assignment just before return is redundant.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

there is a time window between __mmc_send_status() and time_afer(),
on some eMMC chip, the timeout_ms is only 10ms, if this thread was
scheduled out during this period, then, even card has already changes
to transfer state by the result of CMD13, this part of code also treat
it to timeout error.
So, need calculate timeout first, then call __mmc_send_status(), if
already timeout and card still in programing state, then treat it to
the real timeout error.
Signed-off-by: NChaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The mmc_execute_tuning() has already prepared the opcode,
there is no need to prepare it again at mmc_send_tuning(),
and, there is a BUG of mmc_send_tuning() to determine the opcode
by bus width, assume eMMC was running at HS200, 4bit mode,
then the mmc_send_tuning() will overwrite the opcode from CMD21
to CMD19, then got error.

in addition, extend an argument of "cmd_error" to allow getting
if there was cmd error when tune response.
Signed-off-by: NChaotian Jing <chaotian.jing@mediatek.com>
[Ulf: Rebased patch]
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

As there are no users of the __mmc_switch() API, except for the mmc core
itself, let's convert it from an exported function into an internal.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Make a separate function to do the mmc_switch status check
so it can be re-used. This is preparation for adding support
for HS400 re-tuning.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Hold re-tuning during switch commands to prevent
it from conflicting with the busy state or the CMD13
verification.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Since previous patches removed the need for the tuning block patterns
to be exported, let's move them close to the mmc_send_tuning() API.

Those are now intended to be used only by the mmc core.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NJaehoon Chung <jh80.chung@samsung.com>

To be able to use mmc_send_tuning() prior the struct mmc_card has been
allocated, let's convert it to take the struct mmc_host* as parameter
instead.
Suggested-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NDong Aisheng <b29396@freescale.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>

According to the SD card spec, Add a manual tuning command function
for SDR104/HS200.
Sending command 19 or command 21 to read data and compare with the
tunning block pattern.

This patch will help to decrease some platform private codes in SDHCI
platform_execute_tuning() callbacks.
Signed-off-by: NMinda Chen <Minda.Chen@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

While allocating buffers for CXD data, let's use kzalloc() to make sure
those are zeroed.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Due to previous patches, all callers of mmc_send_cxd_data() now
allocates their buffers from the heap. This enables us to simplify
mmc_send_cxd_data() by removing the support of handling buffers, which
are allocated from the stack.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Previous patches has replaced the calls to mmc_send_ext_csd() into
mmc_get_ext_csd(), thus mmc_send_ext_csd() has become redundant. Let's
remove it.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Callers of mmc_send_ext_csd() will be able to decrease code duplication
by using mmc_get_ext_csd() instead. Let's make it available.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

The helper function mmc_can_ext_csd() will return a positive value if
the card supports the EXT_CSD register. Start using it at relavant
places in the mmc core.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Use the much more common pr_warn instead of pr_warning.

Other miscellanea:

o Coalesce formats
o Realign arguments
o Remove extra spaces when coalescing formats
Signed-off-by: NJoe Perches <joe@perches.com>
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>

If the host controller supports busy detection in HW, we expect the
MMC_CAP_WAIT_WHILE_BUSY to be set. Likewise the corresponding
host->max_busy_timeout should reflect the maximum busy detection
timeout supported by the host.

Previously we expected a host that supported MMC_CAP_WAIT_WHILE_BUSY to
cope with any timeout, which just isn't feasible due to HW limitations.

For most switch operations, R1B responses are expected and thus we need
to check for busy detection completion. To cope with cases where the
requested busy detection timeout is greater than what the host are able
to support, we fallback to use a R1 response instead. This will prevent
the host from doing HW busy detection.

In those cases, busy detection completion is handled by polling the for
the card's status using CMD13. This is the same mechanism used when the
host doesn't support MMC_CAP_WAIT_WHILE_BUSY.

Do note, a host->max_busy_timeout set to zero, is interpreted by the
mmc core as it don't know what the host supports. It will then provide
the host with whatever timeout the mmc core finds suitable.

For some cases the mmc core has unfurtunate no clue of what timeout to
use. In these cases we provide the host with a timeout value of zero,
which the host may interpret as use whatever timeout it finds suitable.
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

Instead of using several references to card->host, let's use a local
variable. That means we can remove the BUG_ON verifications for the
same pointers.
Signed-off-by: NUlf Hansson <ulf.hansson@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>

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>

While speed mode is changed, CMD13 cannot be guaranteed.
According to the spec., it is not recommended to use CMD13
to check the busy completion of the timing change.
If CMD13 is used in this case, CRC error must be ignored.
Signed-off-by: NSeungwon Jeon <tgih.jun@samsung.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

Signed-off-by: NMinjian Wu <minjianwu@micron.com>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <cjb@laptop.org>