mmc: support BKOPS feature for eMMC

Enable eMMC background operations (BKOPS) feature.

If URGENT_BKOPS is set after a response, note that BKOPS are required.
Immediately run BKOPS if required.  Read/write operations should be
requested during BKOPS(LEVEL-1), then issue HPI to interrupt the
ongoing BKOPS and service the foreground operation.
(This patch only controls the LEVEL2/3.)

When repeating the writing 1GB data, at a certain time, performance is
decreased.  At that time, card triggers the Level-3 or Level-2.  After
running bkops, performance is recovered.

Future considerations:
 * Check BKOPS_LEVEL=1 and start BKOPS in a preventive manner.
 * Interrupt ongoing BKOPS before powering off the card.
 * How do we get BKOPS_STATUS value (periodically send ext_csd command)?
 * If using periodic bkops, also consider runtime_pm control.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: Replace MMC_CAP2_BROKEN_VOLTAGE with test for fixed regulator

Before this patch, we were using MMC_CAP2_BROKEN_VOLTAGE as a way to
avoid calling regulator_set_voltage() on a fixed regulator, but that's
just duplicating information that already exists -- we should test
whether the regulator is fixed directly, instead of via a capability.

This patch implements that test.  We can't reclaim the capability bit
just yet, since there are still boards in arch/arm/ that reference it;
those references can be removed now.

Reported-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: Fixup broken suspend and eMMC4.5 power off notify

This patch fixes up the broken suspend sequence for eMMC with sleep
support. Additionally it reworks the eMMC4.5 Power Off Notification
feature so it fits together with the existing sleep feature.

The CMD0 based re-initialization of the eMMC at resume is re-introduced
to maintain compatiblity for devices using sleep.

A host shall use MMC_CAP2_POWEROFF_NOTIFY to enable the Power Off
Notification feature. We might be able to remove this cap later on,
if we think that Power Off Notification always is preferred over
sleep, even if the host is not able to cut the eMMC VCCQ power.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Saugata Das <saugata.das@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: Fix some driver hangs when dealing with broken devices

There are infinite loops in the mmc code that can be caused by bad
hardware.  The code will loop forever if the device never comes back
from program mode, R1_STATE_PRG, and it is not ready for data,
R1_READY_FOR_DATA.

A long timeout is added to prevent the code from looping forever.
The timeout will occur if the device never comes back from program
state or the device never becomes ready for data.

It's not clear whether the timeout will do more than log a pr_err()
and then start a fresh hang all over again.  We may need to extend
this patch later to perform some kind of reset of the device (is
that possible?) or rejection of new I/O to the device.

Signed-off-by: Trey Ramsay <tramsay@linux.vnet.ibm.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: Add mmc_set_blockcount feature

Provide support for automatically sending Set Block Count
(CMD23) messages. Used at least for RPMB support.

Signed-off-by: Alex Macro <alex.macro@stericsson.com>
Signed-off-by: Loic Pallardy <loic.pallardy@stericsson.com>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Johan Rudholm <johan.rudholm@stericsson.com>
Acked-by: Krishna Konda <kkonda@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: queue: amend buffer swap for non-blocking transfer

In case both 'req' and 'mq->mqrq_prev->req' are null, there is no request
to be processed. That means there is no need to switch buffer.
Switching buffer is required only after finishing 'issue_fn'.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Per Forlin <per.forlin@stericsson.com>
Tested-by: Johan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: queue: exclude asynchronous transfer for special request

Unlike normal r/w request, special requests(discard, flush)
is finished with a one-time issue_fn. Request change to
mqrq_prev makes unnecessary call.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: move the cache disabling operation to mmc_suspend

Cache control is an eMMC feature and in therefore should be
part of MMC's bus resume operations, performed in mmc_suspend,
rather than in the generic mmc_suspend_host().

Signed-off-by: Maya Erez <merez@codeaurora.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: Add mmc_power_cycle

Add mmc_power_cycle which can be used to power cycle for instance
SD-cards.

Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: Break out start_signal_voltage_switch

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

Also, reset ios.signal_voltage to its original value if
start_signal_voltage_switch fails.

Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: Fixup signal voltage switch

When switching SD and SDIO cards from 3.3V to 1.8V signal levels, the
clock should be gated for 5 ms during the step. After enabling the
clock, the host should wait for at least 1 ms before checking for
failure. Failure by the card to switch is indicated by dat[0:3] being
pulled low. The host should check for this condition and power-cycle
the card if failure is indicated.

Add a retry mechanism for the SDIO case.

If the voltage switch fails repeatedly, give up and continue the
initialization using the original voltage.

This patch places a couple of requirements on the host driver:

 1) mmc_set_ios with ios.clock = 0 must gate the clock
 2) mmc_power_off must actually cut the power to the card
 3) The card_busy host_ops member must be implemented

if these requirements are not fulfilled, the 1.8V signal voltage switch
will still be attempted but may not be successful.

Signed-off-by: Johan Rudholm <johan.rudholm@stericsson.com>
Signed-off-by: Kevin Liu <kliu5@marvell.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: use regulator_can_change_voltage() instead of regulator_count_voltages

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: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: enhance card removal judgement for slow removal

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: Kevin Liu <kliu5@marvell.com>
Tested-by: Johan Rudholm <johan.rudholm@stericsson.com>
Reviewed-by: Philip Rakity <prakity@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: fix performance regression initializing MMC host controllers

Commit fa5501890d8974301042e0202d342a6cbe8609f4 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: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: core: fix init controller performance regression, updated patch

Add MMC_CAP2_NO_PRESCAN_POWERUP to sdhci-pci.c also, use mmc_power_off()
for MMC_CAP2_NO_PRESCAN_POWERUP.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
[cjb: previously applied v1 of this patch instead of v4]
Signed-off-by: Chris Ball <cjb@laptop.org>
mmc: rename random32() to prandom_u32()

Use preferable function name which implies using a pseudo-random
number generator.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Chris Ball <cjb@laptop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert "mmc: use regulator_can_change_voltage() instead of regulator_count_voltages"

This reverts commit 5f56a8e6efb695b6ea7b56e8a33d25ec622e77bd.
Revert "mmc: queue: exclude asynchronous transfer for special request"

This reverts commit d9a72f91e28eba7e702302b230c4b0f33909810f.
Revert "mmc: queue: amend buffer swap for non-blocking transfer"

This reverts commit 8fe2b22b9f903e049cdf265bf77d09ecb3d8e0bf.