mmc: core: Add load based clock scaling support

The SD3.0/eMMC4.5/SDIO3.0 cards can support clock rates upto
200MHz (SDR104 or HS200 bus speed modes). For some workloads
like video playback it isn't necessary for these cards to run
at such high speed. Running at lower frequency, say 50MHz, in
such cases can still meet the deadlines for data transfers.
Scaling down the clock frequency dynamically has huge power
savings not only because the bus is running at lower frequency
but also has an advantage of scaling down the system core
voltage, if supported.

Provide an ondemand clock scaling support similar to cpufreq
ondemand governor having two thresholds, up_threshold and
down_threshold to decide whether to increase the frequency or
scale it down respectively. The sampling interval is in the
order of milliseconds and should be chosen by host drivers that
enable MMC_CAP2_CLK_SCALE capability to take advantage of clock
scaling. The sampling interval mainly depends on the the clock
switching delays and hence a host driver decision. If sampling
interval is too low frequent switching of frequencies can lead
to high power consumption and if sampling interval is too high,
the clock scaling logic would take long time to realize that the
underlying hardware (controller and card) is busy and scale up
the clocks.

Change-Id: I22a5054beec41b0b66b3bf030ddfcf284de448b3
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>

Conflicts:
	drivers/mmc/core/core.c
	include/linux/mmc/host.h
mmc: core: Add sysfs entries for dynamic control of clock scaling

Add sysfs attributes to allow dynamic control of clock scaling
parameters. These attributes are used to enable/disable clock
scaling at runtime and change the up_threshold, down_threshold,
and polling_interval values. Complete documentation for these
sysfs entries are provided at "Documentation/mmc/mmc-dev-attrs.txt".

Change-Id: I4753c75c3b3eeea91e93bceba7af2535b793612e
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
mmc: core: claim mmc host while enabling clock scaling from userspace

A race condition can occur while enabling clock scaling and removal
of the card. If the card is removed just after the host->card check
is successful then there could be NULL pointer dereference later.
Claim mmc host before card availability check to avoid this race
condition.

Change-Id: I6339cad5857732ec6b66280940cd6b8b7ed30614
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
mmc: core: run clock scaling only in valid card state

Clock scaling requires the tuning and if the tuning command
is sent to the card in invalid state, tuning procedure will
fail.

With urgent request mechanism implemented, there is a chance
that clock scaling invoked when card is not in a proper state
to receive the tuning command.

This change checks the card state (by sending the status command)
before invoking the clock scaling request.

Change-Id: Icb71a8e74a9afdc70380a5901cd3d28931959e9c
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
mmc: core: Log MMC clock frequency transitions

Use kernel's ftrace support to capture MMC clock frequency
transitions which can be useful for debugging issues related
to power consumption.

Usage:
mount -t debugfs none /sys/kernel/debug
echo 1 > /sys/kernel/debug/tracing/events/mmc/mmc_clk/enable
cat /sys/kernel/debug/tracing/trace_pipe

Change-Id: I25c4ee39dcbe30e7665902a9f723a5a421b55ca3
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>

Conflicts:
	drivers/mmc/core/core.c
	include/linux/mmc/host.h
mmc: core: Add support for notifying host driver while scaling clocks

Host drivers can participate in clock scaling by registering
->notify_load host operation, which allows host driver to carry out
platform specific operations for further power savings or increasing
throughput based on whether load is LOW or HIGH respectively. This
can be applicable to non-ultra high speed cards as well so remove
the check for ultra high speed cards to initialize clock scaling.

Change-Id: Icaab9520135e384f5470db68b2f25c5cdce5663a
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
msm: vidc: Memset and flush codec context buffers

This change will memset and flush the codec context
buffers for non-secure case to resolve video driver
timer expire issues.

Change-Id: I6669481da3076a392061868475fc9844f2c41064
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>

Conflicts:
	drivers/video/msm/vidc/1080p/ddl/vcd_ddl_vidc.c
msm_serial_hs: Fix Tx path issues during uart shutdown

UART queues tx transfer request to ADM and upon getting completion
callback from ADM, schedules tx tasklet in which it enables the
Tx Ready Interrupt and waits for it. On Tx ready interrupt tx
dma_in_flight is set to zero indicating no more tx data is pending.

This would cause corner case where if uart shutdown function checks
dma_in_flight flag between dmov callback and Tx Ready interrupt,
then this may cause uart shutdown function queuing dmov flush for
the completed Tx command and with this dmov flush callback never
be called. To fix this issue, move the dma_in_flight flag reset from
Tx Ready interrupt to dmov callback.

To avoid issues if any uart clients submitting any Tx requests after
uart shutdown, add is_shutdown flag and check before tx command
submission.

CRs-Fixed: 476745
Change-Id: I05314cf2f8361109302dbc0ddcfb834e9034eab5
Signed-off-by: Saket Saurabh <ssaurabh@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>

Conflicts:
	drivers/tty/serial/msm_serial_hs.c
msm_serial_hs: Fix UART Rx dmov command stall issues

Resetting Rx and Tx HW state machine while Rx dmov command queued
with ADM, caused dmov stall issues. Hence moving the Rx and Tx reset
to after dmov_flush. In order to do this, change the Rx path to not
enqueue dmov request as a part of dmov flush when flush is
FLUSH_IGNORE.

Removing the unnecessary UART Rx and Tx HW Reset in
msm_hs_set_bps_locked().

Require to add few clock cycles after Rx and Tx HW reset, hence
adding 10us delay as safe side. In addition to this, combining
both Rx and Tx reset in single register write.

CRs-Fixed: 481244
Change-Id: Ib33feb55ab42b6d30ce19db945fed7496b78debf
Signed-off-by: Saket Saurabh <ssaurabh@codeaurora.org>

Conflicts:
	drivers/tty/serial/msm_serial_hs.c
mmc: core: Fix NULL pointer dereference

mmc_signal_sdio_irq() should only be called when the function
driver registers for IRQ notification. In case, if any host
driver recieves a spurious interrupt and call mmc_signal_sdio_irq(),
ignore waking up uninitialized sdio irq thread.

CRs-Fixed: 472609
Change-Id: I831717fe80918538a18cc1f2300fe7fe2817c70f
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>
msm_fb: Set backlight to zero during adb shell stop scenario

During framework reboot (adb shell stop/start), the backlight
value might be non-zero after adb shell stop. In such cases,
during adb shell start, we see momentary garbled screen due to
panel-init pattern since backlight is ON. Hence, set backlight
to zero during adb shell stop. Also, store the latest backlight
value before adb shell stop so that backlight can be set soon
after first frame update after adb shell start.

CRs-fixed: 479316
Change-Id: I2a98c2599f5f3fadf516da2df06556f52fe50a2e
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>

Conflicts:
	drivers/video/msm/msm_fb.c
drivers: staging: rename synaptics_i2c_rmi4 to avoid confusion

Synaptics driver in staging directory has the same file
name as the in-use synaptics driver in touchscreen directory.
Rename so that in search it is obvious they are two different
files and both are not enabled.

Change-Id: I53c81fbeb97b95f458dfbb60744cb95aa64c6275
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>