Commit graph

197 commits

Author SHA1 Message Date
Adrian Hunter
d3bf68ae04 mmc: host: Add CQE interface
Add CQE host operations, capabilities, and host members.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-08-30 15:03:33 +02:00
Adrian Hunter
dc8d68bb6c mmc: core: Remove unused MMC_CAP2_PACKED_CMD
Packed commands support was removed but some bits got left behind. Remove
them.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-08-30 14:02:00 +02:00
Shawn Lin
1896f14006 mmc: core: remove check of host->removed for rescan routine
The intention of this check was to prevent the conflict between
hotplug and removing driver for whatever reason. Currently it
doesn't improve anything and the following rescan process could
still saftly perform the scan flow. So these code seems pointless
now and let's remove them.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-08-30 14:01:33 +02:00
Adrian Hunter
03dbaa04a2 mmc: slot-gpio: Add support to enable irq wake on cd_irq
Add host capability MMC_CAP_CD_WAKE to enable irq wake on the card detect
irq.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-06-20 10:30:49 +02:00
Ulf Hansson
d2a47176a8 mmc: core: Remove MMC_CAP2_HC_ERASE_SZ
The MMC_CAP2_HC_ERASE_SZ is used only by a few mmc host drivers. Its intent
is to enable eMMC's high-capacity erase size, as to improve the behaviour
of the erase operations.

We should strive to avoid software configuration options that aren't
necessary, but instead deploy common behaviours. For these reasons, let's
remove the capability bit for MMC_CAP2_HC_ERASE_SZ and make it the default
behaviour.

Note that this change doesn't affect eMMCs supporting trim/discard, because
these commands operates on sectors and takes precedence over erase
commands.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
2017-06-20 10:30:48 +02:00
Linus Walleij
c3dccb74be mmc: core: Delete bounce buffer Kconfig option
This option is activated by all multiplatform configs and what
not so we almost always have it turned on, and the memory it
saves is negligible, even more so moving forward. The actual
bounce buffer only gets allocated only when used, the only
thing the ifdefs are saving is a little bit of code.

It is highly improper to have this as a Kconfig option that
get turned on by Kconfig, make this a pure runtime-thing and
let the host decide whether we use bounce buffers. We add a
new property "disable_bounce" to the host struct.

Notice that mmc_queue_calc_bouncesz() already disables the
bounce buffers if host->max_segs != 1, so any arch that has a
maximum number of segments higher than 1 will have bounce
buffers disabled.

The option CONFIG_MMC_BLOCK_BOUNCE is default y so the
majority of platforms in the kernel already have it on, and
it then gets turned off at runtime since most of these have
a host->max_segs > 1. The few exceptions that have
host->max_segs == 1 and still turn off the bounce buffering
are those that disable it in their defconfig.

Those are the following:

arch/arm/configs/colibri_pxa300_defconfig
arch/arm/configs/zeus_defconfig
- Uses MMC_PXA, drivers/mmc/host/pxamci.c
- Sets host->max_segs = NR_SG, which is 1
- This needs its bounce buffer deactivated so we set
  host->disable_bounce to true in the host driver

arch/arm/configs/davinci_all_defconfig
- Uses MMC_DAVINCI, drivers/mmc/host/davinci_mmc.c
- This driver sets host->max_segs to MAX_NR_SG, which is 16
- That means this driver anyways disabled bounce buffers
- No special action needed for this platform

arch/arm/configs/lpc32xx_defconfig
arch/arm/configs/nhk8815_defconfig
arch/arm/configs/u300_defconfig
- Uses MMC_ARMMMCI, drivers/mmc/host/mmci.[c|h]
- This driver by default sets host->max_segs to NR_SG,
  which is 128, unless a DMA engine is used, and in that case
  the number of segments are also > 1
- That means this driver already disables bounce buffers
- No special action needed for these platforms

arch/arm/configs/sama5_defconfig
- Uses MMC_SDHCI, MMC_SDHCI_PLTFM, MMC_SDHCI_OF_AT91, MMC_ATMELMCI
- Uses drivers/mmc/host/sdhci.c
- Normally sets host->max_segs to SDHCI_MAX_SEGS which is 128 and
  thus disables bounce buffers
- Sets host->max_segs to 1 if SDHCI_USE_SDMA is set
- SDHCI_USE_SDMA is only set by SDHCI on PCI adapers
- That means that for this platform bounce buffers are already
  disabled at runtime
- No special action needed for this platform

arch/blackfin/configs/CM-BF533_defconfig
arch/blackfin/configs/CM-BF537E_defconfig
- Uses MMC_SPI (a simple MMC card connected on SPI pins)
- Uses drivers/mmc/host/mmc_spi.c
- Sets host->max_segs to MMC_SPI_BLOCKSATONCE which is 128
- That means this platform already disables bounce buffers at
  runtime
- No special action needed for these platforms

arch/mips/configs/cavium_octeon_defconfig
- Uses MMC_CAVIUM_OCTEON, drivers/mmc/host/cavium.c
- Sets host->max_segs to 16 or 1
- Setting host->disable_bounce to be sure for the 1 case

arch/mips/configs/qi_lb60_defconfig
- Uses MMC_JZ4740, drivers/mmc/host/jz4740_mmc.c
- This sets host->max_segs to 128 so bounce buffers are
  already runtime disabled
- No action needed for this platform

It would be interesting to come up with a list of the platforms
that actually end up using bounce buffers. I have not been
able to infer such a list, but it occurs when
host->max_segs == 1 and the bounce buffering is not explicitly
disabled.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-06-20 10:30:17 +02:00
Ulf Hansson
682696605c mmc: sdio: Add API to manage SDIO IRQs from a workqueue
For hosts not supporting MMC_CAP2_SDIO_IRQ_NOTHREAD but MMC_CAP_SDIO_IRQ,
the SDIO IRQs are processed from a dedicated kernel thread. For these
cases, the host calls mmc_signal_sdio_irq() from its ISR to signal a new
SDIO IRQ.

Signaling an SDIO IRQ makes the host's ->enable_sdio_irq() callback to be
invoked to temporary disable the IRQs, before the kernel thread is woken up
to process it. When processing of the IRQs are completed, they are
re-enabled by the kernel thread, again via invoking the host's
->enable_sdio_irq().

The observation from this, is that the execution path is being unnecessary
complex, as the host driver already knows that it needs to temporary
disable the IRQs before signaling a new one. Moreover, replacing the kernel
thread with a work/workqueue would not only greatly simplify the code, but
also make it more robust.

To address the above problems, let's continue to build upon the support for
MMC_CAP2_SDIO_IRQ_NOTHREAD, as it already implements SDIO IRQs to be
processed without using the clumsy kernel thread and without the ping-pong
calls of the host's ->enable_sdio_irq() callback for each processed IRQ.

Therefore, let's add new API sdio_signal_irq(), which enables hosts to
signal/process SDIO IRQs by using a work/workqueue, rather than using the
kernel thread.

Add also a new host callback ->ack_sdio_irq(), which the work invokes when
the SDIO IRQs have been processed. This informs the host about when it
shall re-enable the SDIO IRQs. Potentially, we could re-use the existing
->enable_sdio_irq() callback instead of adding a new one, however it has
turned out that it's more convenient for hosts to get this information via
a separate callback.

Hosts that wants to use this new method to signal/process SDIO IRQs, must
enable MMC_CAP2_SDIO_IRQ_NOTHREAD and implement the ->ack_sdio_irq()
callback.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
2017-06-20 10:30:11 +02:00
Heiner Kallweit
6335d68349 mmc: core: add mmc_get_dma_dir
Add function for determining DMA direction to core.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2017-04-24 21:41:52 +02:00
Ulf Hansson
20f921bb01 mmc: core: Invent MMC_CAP_3_3V_DDR
According the JEDEC specification an eMMC card supporting 1.8V vccq in DDR
mode should also be capable of 3.3V. However, it's been reported that some
mmc hosts supports 3.3V, but not 1.8V.

Currently the mmc core implements an error handling when the host fails to
set 1.8V for vccq, by falling back to 3.3V. Unfortunate, this seems to be
insufficient for some mmc hosts. To enable these to use eMMC DDR mode let's
invent a new mmc cap, MMC_CAP_3_3V_DDR, which tells whether they support
the eMMC 3.3V DDR mode.

In case MMC_CAP_3_3V_DDR is set, but not MMC_CAP_1_8V_DDR, let's change to
remain on the 3.3V, as it's the default voltage level for vccq, set by the
earlier power up sequence.

As this change introduces MMC_CAP_3_3V_DDR, let's take the opportunity to
do some re-formatting of the related defines in the header file.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Jan Glauber <jglauber@cavium.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
2017-02-13 13:20:44 +01:00
Ulf Hansson
5857b29b96 mmc: core: Move public functions from host.h to private headers
A significant amount of functions are available through the public mmc
host.h header file. Let's slim down this public mmc interface, as to
prevent users from abusing it, by moving some of the functions to private
mmc host.h header file.

This change concentrates on moving the functions into private mmc headers,
following changes may continue with additional clean-ups.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
2017-02-13 13:20:25 +01:00
Ulf Hansson
9e1bbc7272 mmc: core: Move some host specific public functions to host.h
Ideally the public mmc header file, core.h, shouldn't contain interfaces
particularly intended to be used by host drivers. Instead those should
remain in the host.h header file. Therefore, let's move a couple functions
from core.h to host.h.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
2017-02-13 13:20:21 +01:00
Ulf Hansson
8da007348b mmc: core: First step in cleaning up public mmc header files
This is the first step in cleaning up the public mmc header files. In this
change we makes sure each header file builds standalone, as that helps to
resolve dependencies.

While changing this, it also seems reasonable to stop including other
headers from inside a header itself which it don't depend upon.
Additionally, in some cases such dependencies are better resolved by
forward declaring the needed struct.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
2017-02-13 13:20:19 +01:00
Adrian Hunter
e0097cf5f2 mmc: queue: Fix queue thread wake-up
The only time the driver sleeps expecting to be woken upon the arrival of
a new request, is when the dispatch queue is empty. The only time that it
is known whether the dispatch queue is empty is after NULL is returned
from blk_fetch_request() while under the queue lock.

Recognizing those facts, simplify the synchronization between the queue
thread and the request function. A couple of flags tell the request
function what to do, and the queue lock and barriers associated with
wake-ups ensure synchronization.

The result is simpler and allows the removal of the context_info lock.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Harjani Ritesh <riteshh@codeaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-12-05 10:31:03 +01:00
Linus Walleij
03d640ae1f mmc: block: delete packed command support
I've had it with this code now.

The packed command support is a complex hurdle in the MMC/SD block
layer, around 500+ lines of code which was introduced in 2013 in

commit ce39f9d17c ("mmc: support packed write command for eMMC4.5
devices")
commit abd9ac1449 ("mmc: add packed command feature of eMMC4.5")

...and since then it has been rotting. The original author of the
code has disappeared from the community and the mail address is
bouncing.

For the code to be exercised the host must flag that it supports
packed commands, so in mmc_blk_prep_packed_list() which is called for
every single request, the following construction appears:

u8 max_packed_rw = 0;

if ((rq_data_dir(cur) == WRITE) &&
    mmc_host_packed_wr(card->host))
        max_packed_rw = card->ext_csd.max_packed_writes;

if (max_packed_rw == 0)
    goto no_packed;

This has the following logical deductions:

- Only WRITE commands can really be packed, so the solution is
  only half-done: we support packed WRITE but not packed READ.
  The packed command support has not been finalized by supporting
  reads in three years!

- mmc_host_packed_wr() is just a static inline that checks
  host->caps2 & MMC_CAP2_PACKED_WR. The problem with this is
  that NO upstream host sets this capability flag! No driver
  in the kernel is using it, and we can't test it. Packed
  command may be supported in out-of-tree code, but I doubt
  it. I doubt that the code is even working anymore due to
  other refactorings in the MMC block layer, who would
  notice if patches affecting it broke packed commands?
  No one.

- There is no Device Tree binding or code to mark a host as
  supporting packed read or write commands, just this flag
  in caps2, so for sure there are not any DT systems using
  it either.

It has other problems as well: mmc_blk_prep_packed_list() is
speculatively picking requests out of the request queue with
blk_fetch_request() making the MMC/SD stack harder to convert
to the multiqueue block layer. By this we get rid of an
obstacle.

The way I see it this is just cruft littering the MMC/SD
stack.

Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Maya Erez <qca_merez@qca.qualcomm.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-11-29 09:05:27 +01:00
Linus Walleij
d3c6aac3bd mmc: delete is_first_req parameter from pre-request callback
The void (*pre_req) callback in the struct mmc_host_ops vtable
is passing an argument "is_first_req" indicating whether this is
the first request or not.

None of the in-kernel users use this parameter: instead, since
they all just do variants of dma_map* they use the DMA cookie
to indicate whether a pre* callback has already been done for
a request when they decide how to handle it.

Delete the parameter from the callback and all users, as it is
just pointless cruft.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-11-29 09:05:27 +01:00
Simon Horman
c820af5f18 mmc: core: Add helper to see if a host can be retuned
This is in preparation for restoring saved tuning parameters
when resuming the TMIO driver.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-11-29 09:00:54 +01:00
Linus Walleij
8e8b3f514c mmc: core: use enum mmc_blk_status properly
There were several instances of code using the
enum mmc_blk_status by arbitrarily converting it to an int and
throwing it around to different functions. This makes the code
hard to understand to may give rise to strange errors.

Especially the function prototype mmc_start_req() had to be
modified to take a pointer to an enum mmc_blk_status and the
function pointer .err_check() inside struct mmc_async_req
needed to return an enum mmc_blk_status.

In every case: instead of assigning the block layer error code
to an int, use the enum, also change the signature of all
functions actually passing this enum to use the enum.

To make it possible to use the enum everywhere applicable, move
it to <linux/mmc/core.h> so that all code actually using it can
also see it.

An interesting case was encountered in the MMC test code which
did not return a enum mmc_blk_status at all in the .err_check
function supposed to check whether asynchronous requests worked
or not: instead it returned a normal -ERROR or even the test
frameworks internal error codes.

The test code would also pass on enum mmc_blk_status codes as
error codes inside the test code instead of converting them
to the local RESULT_* codes.

I have tried to fix all instances properly and run some tests
on the result.

Cc: Chunyan Zhang <zhang.chunyan@linaro.org>
Cc: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-11-29 09:00:51 +01:00
Adrian Hunter
5163af5a5e mmc: core: Add support for sending commands during data transfer
A host controller driver exposes its capability using caps flag
MMC_CAP_CMD_DURING_TFR. A driver with that capability can accept requests
that are marked mrq->cap_cmd_during_tfr = true. Then the driver informs the
upper layers when the command line is available for further commands by
calling mmc_command_done(). Because of that, the driver will not then
automatically send STOP commands, and it is the responsibility of the upper
layer to send a STOP command if it is required.

For requests submitted through the mmc_wait_for_req() interface, the caller
sets mrq->cap_cmd_during_tfr = true which causes mmc_wait_for_req() in fact
not to wait. The caller can then send commands that do not use the data
lines. Finally the caller can wait for the transfer to complete by calling
mmc_wait_for_req_done() which is now exported.

For requests submitted through the mmc_start_req() interface, the caller
again sets mrq->cap_cmd_during_tfr = true, but mmc_start_req() anyway does
not wait. The caller can then send commands that do not use the data
lines. Finally the caller can wait for the transfer to complete in the
normal way i.e. calling mmc_start_req() again.

Irrespective of how a cap_cmd_during_tfr request is started,
mmc_is_req_done() can be called if the upper layer needs to determine if
the request is done. However the appropriate waiting function (either
mmc_wait_for_req_done() or mmc_start_req()) must still be called.

The implementation consists primarily of a new completion
mrq->cmd_completion which notifies when the command line is available for
further commands. That completion is completed by mmc_command_done().
When there is an ongoing data transfer, calls to mmc_wait_for_req() will
automatically wait on that completion, so the caller does not have to do
anything special.

Note, in the case of errors, the driver may call mmc_request_done() without
calling mmc_command_done() because mmc_request_done() always calls
mmc_command_done().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-09-26 21:31:28 +02:00
Shawn Lin
a0c3b68c72 mmc: core: Allow hosts to specify non-support for MMC commands
Host drivers which needs to valdiate for non-supported MMC
commands and returnn error code for such requests.

To improve and simplify the behaviour, let's invent MMC_CAP2_NO_MMC
which these host drivers can set to tell the mmc core to skip sending MMC
commands during card initialization.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25 10:34:47 +02:00
Ulf Hansson
1b8d79c549 mmc: core: Allow hosts to specify non-support for SD commands
There are host drivers which needs to valdiate for non-supported SD
commands and returnn error code for such requests.

To improve and simplify the behaviour, let's invent MMC_CAP2_NO_SD
which these host drivers can set to tell the mmc core to skip sending SD
commands during card initialization.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25 10:34:22 +02:00
Shawn Lin
81ac2af657 mmc: core: implement enhanced strobe support
Controllers use data strobe line to latch data from devices
under hs400 mode, but not for cmd line. So since emmc 5.1, JEDEC
introduces enhanced strobe mode for latching cmd response from
emmc devices to host controllers. This new feature is optional,
so it depends both on device's cap and host's cap to decide
whether to use it or not.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25 10:34:05 +02:00
Shawn Lin
ef29c0e273 mmc: core: add mmc-hs400-enhanced-strobe support
This patch introduce mmc-hs400-enhanced-strobe for platforms
which want to enable enhanced strobe function from DT if the
mmc host controller claims to support enhanced strobe.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-07-25 10:34:05 +02:00
Adrian Hunter
7ff2760999 mmc: core: Add a facility to "pause" re-tuning
Re-tuning is not possible when switched to the RPMB
partition.  However re-tuning should not be needed
if re-tuning is done immediately before switching,
a small set of operations is done, and then we
immediately switch back to the main partition.

To ensure that re-tuning can't be done for a short
while, add a facility to "pause" re-tuning.

The existing facility to hold / release re-tuning
is used but it also flags re-tuning as needed to cause
re-tuning before the next command (which will be the
switch to RPMB).

We also need to "unpause" in the recovery path, which
is catered for by adding it to mmc_retune_disable().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-05-17 16:54:26 +02:00
Wolfram Sang
93b6911ac1 mmc: host: add note that set_ios needs to handle 0Hz properly
While here, refactor the comments so that they are before the
declaration they are referring to.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2016-05-02 10:33:14 +02:00
Carlo Caione
100a606d54 mmc: core: Introduce MMC_CAP2_NO_SDIO cap
This patch introduce a new MMC_CAP2_NO_SDIO cap used to tell the mmc
core to not send SDIO specific commands.

Signed-off-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22 11:32:13 +01:00
Ulf Hansson
8dede18e2e mmc: core: Refactor code to register the MMC PM notifier
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: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22 11:32:04 +01:00
Ulf Hansson
7b6471a968 mmc: core: Remove MMC_CAP_RUNTIME_RESUME as it's redundant
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-22 11:32:03 +01:00
Douglas Anderson
2086f801cb mmc: core: Add mmc_regulator_set_vqmmc()
This adds logic to the MMC core to set VQMMC.  This is expected to be
called by MMC drivers like dw_mmc as part of (or instead of) their
start_signal_voltage_switch() callback.

A few notes:

* When setting the signal voltage to 3.3V we do our best to make VQMMC
  and VMMC match.  It's been reported that this makes some old cards
  happy since they were tested back in the day before UHS when VQMMC
  and VMMC were provided by the same regulator.  A nice side effect of
  this is that we don't end up on the hairy edge of VQMMC (2.7V),
  which some EEs claim is a little too close to the minimum for
  comfort.
  This is done in two steps. At first we try to find a VQMMC within
  a 0.3V tolerance of VMMC and if this is not supported by the
  supplying regulator we try to find a suitable voltage within the
  whole 2.7V-3.6V area of the spec.

* The two step approach is currently necessary, as the used
  regulator_set_voltage_triplet(min, target, max) uses a simple
  implementation that just tries two basic steps:
	regulator_set_voltage(target, max);
	regulator_set_voltage(min, target);
  So with only one step with 2.7-3.6V borders, if a suitable voltage
  is a bit below VMMC, we would directly get the lowest 2.7V
  which some boards (like Rockchips) don't like at all.

* When setting the signal voltage to 1.8V or 1.2V we aim for that
  specific voltage instead of picking the lowest one in the range.

* We very purposely don't print errors in mmc_regulator_set_vqmmc().
  There are cases where the MMC core will try several different
  voltages and we don't want to pollute the logs.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-10-26 16:00:10 +01:00
Ulf Hansson
9eadcc0581 mmc: core: Remove MMC_CLKGATE
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: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
2015-10-26 16:00:09 +01:00
Yangbo Lu
f13e5b9f3c mmc: sdio: avoid using NULL sdio_irq_thread pointer
For Freescale QorIQ LS1021AQDS board, there is a SDIO interrupt
in the process of resume without inserting SD adapter because of
some unknown issue. But the driver doesn't assign sdio_irq_thread
pointer. This will block the resume of kernel. This patch is used
to avoid using NULL sdio_irq_thread pointer.

Signed-off-by: Yangbo Lu <yangbo.lu@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-08-17 11:32:46 +02:00
Adrian Hunter
f168359efb mmc: core: Add 'card' to drive strength selection callback
In preparation for supporting also eMMC drive strength,
add the 'card' as a parameter so that the callback can
distinguish different types of cards if necessary.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01 09:07:12 +02:00
Adrian Hunter
b4f30a174e mmc: core: Allow card drive strength to be different to host
Initialization of UHS-I modes for SD and SDIO cards
employs a callback to allow the host driver to
choose a drive strength value. Currently that
assumes the card drive strength and host driver
type must be the same value. Change to let the
callback make that decision and return both the
card drive strength and host driver type.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01 09:07:11 +02:00
Lars-Peter Clausen
9f6e0bff2a mmc: Add support for disabling write-protect detection
It is not uncommon to see systems where there is no physical write-protect
signal (e.g. when using eMMC or microSD card slots). For some controllers,
which have a dedicated write-protection detection logic (like SDHCI
controllers), the get_ro() callback can return bogus data in such a case.

Instead of handling this on a per controller basis this patch adds a new
capability flag to the MMC core that can be set to specify that the result
of get_ro() is invalid. When the flag is set the core will not call
get_ro() and assume that the card is always read-write.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01 09:06:59 +02:00
Adrian Hunter
dfa13ebbe3 mmc: host: Add facility to support re-tuning
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: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-06-01 09:06:53 +02:00
NeilBrown
4043326733 mmc: core: Remove the ->enable|disable() callbacks
These callbacks have been set to deprecated for some time. The last
user (omap_hsmmc) has moved away from using them, which thus enables
us to completely remove them.

Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-03-27 10:57:55 +01:00
Ulf Hansson
3aa8793f75 mmc: core: Initial support for MMC power sequences
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: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
2015-01-28 12:31:12 +01:00
Ulf Hansson
df8aca162e mmc: slot-gpio: Rework how to handle allocation of slot-gpio data
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: Ulf Hansson <ulf.hansson@linaro.org>
2015-01-19 09:56:18 +01:00
Adrian Hunter
549c0b1848 mmc: sdhci: Clear also HS400 1.2V capability if 1.2V is not supported
1.2V HS200 mode capability is cleared if there is not a voltage
regulator that supports 1.2V.  Do the same for 1.2V HS400 mode.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-11-26 14:30:51 +01:00
Roger Tseng
8af465db96 mmc: core: Add new power_mode MMC_POWER_UNDEFINED
Add MMC_POWER_UNDEFINED for power_mode in struct mmc_ios and use it as
the initial value of host->ios.power_mode.

For hosts with MMC_CAP2_NO_PRESCAN_POWERUP, this makes the later
mmc_power_off() do real power-off things instead of NOP, and further
prevents state messed up in cards that was already initialized (eg. by
BIOS of UEFI driver).

Signed-off-by: Roger Tseng <rogerable@realtek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-09-24 11:20:04 +02:00
Kuninori Morimoto
0abb71feb2 mmc: remove MMC_CAP2_NO_MULTI_READ flags
Now, mmc framework uses multi_io_quirk
for I/O HW bug workaround.
MMC_CAP2_NO_MULTI_READ flag is no longer needed

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-09-09 14:15:43 +02:00
Kuninori Morimoto
2e47e84245 mmc: Add .multi_io_quirk callback for multi I/O HW bug
Historically, we have been using MMC_CAP* to handle host HW issues and
currently the block layer uses MMC_CAP2_NO_MULTI_READ flag for a multi
I/O HW bug workaround.

There are a few tweaks needed to make MMC_CAP2_NO_MULTI_READ suite all
situations. Therefore let's add an optional host ops callback to enable
host drivers to return the number of blocks it allows per request.

In a future patch and when host drivers have converted to the new
callback, MMC_CAP2_NO_MULTI_READ shall be removed.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-09-09 13:59:25 +02:00
Sascha Hauer
3d705d14fe mmc: implement Driver Stage Register handling
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-09-09 13:59:07 +02:00
Russell King
bf3b5ec66b mmc: sdio_irq: rework sdio irq handling
Rather than the SDIO support spawning it's own thread for handling card
interrupts, use the generic IRQ infrastructure for this, triggering it
from the host interface's interrupt handling directly.

This avoids a race between the parent thread waiting to receive an
interrupt response from the card, and the slow startup from the sdio
irq thread, which can occur as a result of high system load (eg, while
udev is running.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Markus Pargmann <mpa@pengutronix.de>
Tested-by: Stephen Warren <swarren@nvidia.com>
[Ulf Hansson] Resolved conflict
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-22 07:26:03 -04:00
Tim Kryger
4d1f52f9a9 mmc: core: Improve support for deferred regulators
Callers of mmc_regulator_get_supply could benefit from knowing if either
of the regulators are present but not yet available.  Since callers do
not currently examine the return value, modify this function to return
zero or -EPROBE_DEFER if either regulator get returns the same.

Furthermore, since callers check vmmc/vqmmc using IS_ERR and can deal
with absent regulators, switch to devm_regulator_get_optional. This has
the added benefit of allowing this function to behave correctly even in
the !CONFIG_REGULATOR case such that the stub can be removed.

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-12 18:08:24 -04:00
Seungwon Jeon
0a5b6438ee mmc: add support for HS400 mode of eMMC5.0
This patch adds HS400 mode support for eMMC5.0 device.  HS400 mode is high
speed DDR interface timing from HS200.  Clock frequency is up to 200MHz
and only 8-bit bus width is supported. In addition, tuning process of
HS200 is required to synchronize the command response on the CMD line
because CMD input timing for HS400 mode is the same as HS200 mode.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Jackey Shen <jackey.shen@amd.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-12 18:06:06 -04:00
Seungwon Jeon
2415c0ef61 mmc: identify available device type to select
Device types which are supported by both host and device can be
identified when EXT_CSD is read. There is no need to check host's
capability anymore.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-12 18:05:57 -04:00
Seungwon Jeon
cdc991790c mmc: drop the speed mode of card's state
Timing mode identifier has same role and can take the place
of speed mode. This change removes all related speed mode.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-12 18:05:53 -04:00
Markus Mayer
fa372a51cb mmc: Delay the card_event callback into the mmc_rescan worker
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/2014/3/19/79

Signed-off-by: Markus Mayer <markus.mayer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-04-22 07:06:36 -04:00
Seungwon Jeon
79f7ae7c45 mmc: clarify DDR timing mode between SD-UHS and eMMC
This change distinguishes DDR timing mode of current
mixed usage to clarify device type.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-04-20 16:59:28 -04:00
Ulf Hansson
68eb80e06b mmc: core: Rename max_discard_to to max_busy_timeout
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: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-02-23 10:40:08 -05:00