The P2020 has a non-standard implementation of the SDHCI_HOST_CONTROL
register. This patch adds a QUIRK in the SDHCI header to signal that
a host controller has a non-standard SDHCI_HOST_CONTROL register. The
patch adds a check to the function esdhc_writeb in file
sdhci-of-esdhc.c, where it checks if the write is done to the
SDHCI_HOST_CONTROL register and th host has the above mentioned QUIRK,
then the function simply returns instead of writing to the register.
The patch also detects if the processor is P2020 (by looking in dev
tree) and if so, adds the QUIRK to the host->quirk2

Signed-off-by: Oded Gabbay <ogabbay@advaoptical.com>
Reviewed-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

Although the HC supports HS200 (eMMC) the caps2 are always zero; this
means there's no way to use the super speed mode (when init the card).

If the HC support SDR104, for SD3.0, so it also supports HS200 for eMMC
and this patch just sets the MMC_CAP2_HS200 in the host caps2 field.

Reported-by: Youssef Triki <youssef.triki@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Reviewed-by: Philip Rakity <prakity@nvidia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

MMC_CAP2_FULL_PWR_CYCLE shall be set by host drivers which are able to
do a complete power cycle of the card. In the eMMC case that includes
both vcc and vccq.

This CAP is providing the protocol layer with important information,
needed to take optimized decisions during card initialization and in
the suspend/resume sequence.

MMC_CAP2_POWEROFF_NOTIFY is replaced by MMC_CAP2_FULL_PWR_CYCLE, since
it makes sense to use a wider scope for it.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

Considering shutdown of the card, the responsibility to initate this
sequence shall be driven from the mmc_bus.

This patch enables the mmc_bus to handle this sequence properly. A new
.shutdown callback is added in the mmc_driver struct which is used to
shutdown the blk device.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

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

In particular, this is needed if the GPIO allocation may return
EPROBE_DEFER.

Signed-off-by: Simon Baatz <gmbnomis@gmail.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

If card power is dependent on SD bus power then the host controller
must not be runtime suspended while the card is powered up.  Add
the ability to stay runtime-resumed in that case and enable it with a new
quirk SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

Use the saved values in card->ext_csd when selecting power class.
By doing this the power class will be selected even if mmc_init_card
is called with oldcard != NULL, which is the case after a suspend/resume.

Today ext_csd is NULL if mmc_init_card is called with oldcard != NULL
and power class will not be selected.

According to the eMMC specification the POWER_CLASS value is reset after
power failure, H/W reset assertion and any CMD0 reset.

Signed-off-by: Fredrik Soderstedt <fredrik.soderstedt@stericsson.com>
Reviewed-by: Johan Rudholm <jrudholm@gmail.com>
Acked By: Girish K S <girish.shivananjappa@linaro.org>
Signed-off-by: Chris 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: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

Aggressive power management is suitable when saving power is
essential. At request inactivity timeout, aka pm runtime
autosuspend timeout, the card will be suspended.

Once a new request arrives, the card will be re-initalized and
thus the first request will suffer from a latency. This latency
is card-specific, experiments has shown in general that SD-cards
has quite poor initialization time, around 300ms-1100ms. eMMC is
not surprisingly far better but still a couple of hundreds of ms
has been observed.

Except for the request latency, it is important to know that
suspending the card will also prevent the card from executing
internal house-keeping operations in idle mode. This could mean
degradation in performance.

To use this feature make sure the request inactivity timeout is
chosen carefully. This has not been done as a part of this patch.

Enable this feature by using host cap MMC_CAP_AGGRESSIVE_PM and
by setting CONFIG_MMC_UNSAFE_RESUME.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris 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: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>