msm_serial_hs: Cleanup code to configure/unconfigure UART GPIOs

With current approach UART GPIOs are configure/unconfigure from
board files by using GPIOLib APIs. UART driver uses gpio_config
pdata based function pointer to call per uart device related API
from board file for the same. Hence correct this approach and
pass only UART GPIOs numbers to UART driver using pdata and
configure/unconfigure those GPIOs using GPIOLib APIs once UART
port is being opened and closed respectively.

CRs-Fixed: 460961
Change-Id: I4bb007b2b476525cb50dd2eb5788c735aae0e32d
Signed-off-by: Mayank Rana <mrana@codeaurora.org>

Conflicts:
	arch/arm/mach-msm/board-8064.c
	arch/arm/mach-msm/board-8930.c
msm_serial_hs: Donot register UART device as PM runtime active

Currently UART device is being registered as PM runtime active
in probe() and set as suspended in shutdown(). With this UART
driver PM runtime suspend is being called when system suspend
is invoked and while resuming from the same which invokes UART
driver LPM functionality. It causes UART communication to stop
if both UART Tx and RX FIFO are empty.

This change donot register UART device as PM runtime active
device as UART driver doesn't use PM runtime APIs for its LPM
functionality.

Change-Id: I33d0c95e4227fdb1b7d6d514498e161e6e4df465
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
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>
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>
msm_serial_hs: Fix synchronization between ADM and UART Cores

With current UART Core programming sequence, it is seen that ADM
and UART Core are going out of sync in few usecases with regression.
It is fixed by using Force RxStale feature of UART Core from
set_termios() and sending discard flush to ADM which would terminate
currently queued UART RX CMD to ADM. Add termios_in_progress check
to make decision about what kind flush to send on receiving RxStale
interrupt. It makes set_termios() more reboust and also keeps ADM
and UART Core in-sync.

Add dma_in_flight to keep check of UART Rx CMD status and BUG_ON if
UART driver is trying to queue one more UART RX CMD to ADM as UART
driver re-uses same UART RX CMD.

This change also adds check of currently set uartclk rate and next
required uartclk rate for new baud rate. If both are same it would
not call clk_set_rate() to set same uartclk rate again.

UART baud rate change request (i.e. executing set_termios()) can come
asynchronously and time to program ADM hardware with queued CMD by ADM
driver is non-deterministic. It is required by UART driver to confirm
that queued RX CMD is programmed with ADM hardware before going with
requested baud rate change operation. Hence this change wait in
set_termios() for ADM driver to program queued RX CMD before going ahead
with baud rate. Otherwise ADM may encounter data bus error with UART RX
channel which is unrecoverable.

Change-Id: I678e91420b33a49ce8b6a5a29c6309f9ff6f5c4a
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
msm_serial_hs: Disable UART RxStale before Force RxStale in set_termios

There is possible race for handling normal RxStale event and Force
Rxstale event with UART Core, when Force RxStale is issued from
set_termios(). Hence on baud rate change request disable RxStale event
mechanism, and invoke Force RxStale. With RxStale event mechanism
disabled, Force RxStale still generates interrupt.

Fix possible race condition if before completion of previous UART RX CMD
flush, set_termios() request is received. With this case it is quite
possible that rx_tlet() queues one UART RX CMD with ADM driver and also
set_termios() queues one more UART RX CMD which would results with
queueing same UART RX CMD twice with ADM driver. With this device would
crash as the ADM driver will not be able to de-reference the second UART
RX CMD work. Hence add check in set_termios with rx.flush value as
FLUSH_DATA_READY which confirms that flush is initiated but it is not
completed and wait for rx.flush to become FLUSH_NONE which would happen
only once flush is completed and new UART RX CMD is being queued with ADM
driver.

Reduce waiting time for discard flush completion as it is already waited
for queued UART Rx CMD to be programmed with ADM hardware. Hence change
wait time out from 300 jiffies to 50 mseconds.

Add an API to get important UART core registers values which can be called
from error condition. Use the same when discard flush timeout happens with
set_termios(), when rx.dma_in_flight is not set with set_termios() and when
multiple UART RX CMD queueing condition is seen in msm_hs_start_rx_locked()
API.

CRs-Fixed: 486260
Change-Id: I9fd17e453fad619609e76e8b3a72a4f47210cff9
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
msm_serial_hs: Improve UART Shutdown path

For uart port close operation, serial core calls msm_hs_stop_rx_locked()
which sends discard flush request to ADM driver after changing rx.flush
state machine from FLUSH_NONE to FLUSH_STOP value. Next serial core
calls msm_hs_shutdown()and it waits for discard flush completion with
rx.flush state machine to be set as FLUSH_SHUTDOWN to complete uart
port close operation. With this approach, transfer termination is not
known by UART Core which may still allow UART core to make CRCI request
with ADM Core if new data is being received from remote uart. Hence
invoke Force RxStale from msm_hs_stop_rx_locked() which informs UART
core to terminate current Rx transfer and do not make any new CRCI
request with ADM core for any new incoming data. On receiving RxStale
interrupt, it sends discard flush request to ADM driver to terminate
transfer with ADM hardware.

This new programming sequence is required to get both UART and ADM
hardwares in-sync for termination of transfer.

CRs-Fixed: 475230
Change-Id: I802a456294d4fd2fa51a5f4e918a4f4f22bc5ee3
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
msm_serial_hs: Fixing issue during UART shutdown

During UART port close in msm_hs_shutdown(), flag is_shutdown is
set as true and then UART interrupt is disabled and UART irq line
is freed. This is causing corner case in which even if uart shutdown
is in progress, UART interrupt can come as the UART interrupt is not
disabled and UART irq line not freed at this point. As flag
is_shutdown is set as true in msm_hs_shutdown() and then if UART
interrupt comes, it is hitting BUG_ON in UART Interrupt handler
msm_hs_isr(). To fix this issue, disable the UART irq and free
the UART irq line at the beginning of the msm_hs_shutdown() and
then set the flag is_shutdown.

In msm_hs_shutdown, disabling UART Interrupt and setting flag
is_shutdown is done with uart spinlock acquired. There is a
possibility that on other core, msm_hs_isr() might need to wait
for the same uart spinlock and later when msm_hs_isr() is executed
BUG_ON is hit. As by this time all UART Interrupt is disabled,
hence removing the BUG_ON and instead keep prints to notify the
same.

CRs-Fixed: 487945
Change-Id: I0a19b8f3098f1c9215935ca7fa9d9e5895c44a8c
Signed-off-by: Saket Saurabh <ssaurabh@codeaurora.org>
msm_serial_hs: Use RFR GPIO to communicate remote uart

CTS and RFR GPIOs are used for hardware flow control between
two uarts. RFR GPIO provides current status of uart receiver
to remote uart and based on this remote uart sends data.
Hence use this functionality to prevent remote uart to send
data when port is being opened, baud rate change operation
is in progress and port is being closed.

This change also set UART_DM_MR2 (Bit: 8 and 9) before
configuring connected UART GPIOs to prevent RX_BREAK character
and any character having PARTIY or FRAMING error which can be
generated due to configuration of those GPIOs. Allows those
character once port is opened successfuly.

This change also zeroed uart rx software buffer which would
help to see how many bytes copied by ADM from received data
with UART RX FIFO to this memory. This would be useful if
there is any Rx Stall issue is seen.

CRs-Fixed: 495564
Change-Id: I69382994356073c4c86f205015503c935ad09e8d
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
msm_serial_hs: Rx discard flush timeout

While configuring the uart buadrate using set_termios
function, timeout is occuring for rx discard flush
operation. This is due to the driver is waiting for
less time for the DMA call back to occur after programing
the DMA register with the discard flush command.

To overcome this issue increased the timeout to 300ms.

Change-Id: I60db1f9eea8bb59fab4024e5f5dfcbcdcde253bb
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>
msm_serial_hs: Increase rx buffer size to 1024bytes

Increase the UARTDM rx buffer size from 512 bytes
to 1024 bytes. This patch helps to increase the
rx data rates of the clients that uses serial_hs driver.

CRs-Fixed: 514385
Change-Id: I2956020af299dda849cfbef795728da2d8664c77
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>
msm_serial_hs:Enable Error/Break Char off

Following the Hardware Sequence enabling
RX_ERROR_CHAR_OFF and RX_BREAK_ZERO_CHAR_OFF in
MR2 register, for not allowing the Break and
parity/frame Error characters into Rx FIFO.

CR Fixed: CR538141

Change-Id: I1b6aaf60e6850cf6281abcc3c841bb6a316e81a4
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>
msm_serial_hs:Wake locks

Adding wake locks while issuing force stale event

CR Fixed: CR538259
Change-Id: I47b55831154f34cbb8e1aaa3a7d11ed2b652e804
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>
msm_seial_hs:Removing call to Spin unlock twice

During Clock_on() spin_unlock() is called twice.
This patch makes sure that spin_unlock is not
called twice

CRs-Fixed: 546205
Change-Id: Id2cf3d52f94d3773de9206d22bcfa9075615902b
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>
msm_serial_hs: Vote for Clocks

Using msm_hs_clock_vote and msm_hs_clock_unvote APIs
to enable/disable the clocks
Client can explicitly turn off the clocks while BT
is in progress without notifying to tty layer,then
TTY layer tries to access UART resulting in
un-clocked register access.As there is no notification
to TTY layer UART implicitly turns Clock ON

CRs-Fixed: 546219
Change-Id: Ic1f97a757305e817411e8664ea0b4604eff3c5ca
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>

Conflicts:
	drivers/tty/serial/msm_serial_hs.c
msm_serial_hs: Programming Auto RFR Ctrl bit

1.)Disable the auto RFR before forcibly making the RFR
line HIGH from the driver to avoid the controller
changing it's state with out driver's knowledge and
enable the auto RFR instead of making the RFR line
forcibly LOW.So that controller will make it LOW
based on the rx FIFO condition

2.)Due to unexpected data received from the client during
clock off sequence, the clock off sequence is going
into wrong state and eventually leads to uart hardware
mess up
This patch doesn't allow any data from the client during
clock off sequence is in progress

CRs-Fixed: 546216
Change-Id: I10ce82124163e8cf9a0603302d4f128ca255214d
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>

Conflicts:
	drivers/tty/serial/msm_serial_hs.c
mogami: msm_serial_hs: Increase rx buffer size to 1024bytes
Fix msm_serial_hs build

* I need to check if we still need this wakelock bypass hack