In ST16650V2 based serial uarts, while initalizing the PM state,
LCR registers are being initialized to 0 in serial8250_set_sleep().
If console port is already initialized and being used, this will
throws garbage in the console.
Signed-off-by: NSudhir Sreedharan <ssreedharan@mvista.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes commit 2dea53bf,
"serial: of-serial: add PM suspend/resume support", which disables
the uart clock on suspend, but also causes a hardware hang on register
access if no_console_suspend command line option is used.

Also, not every of_serial device is an 8250 port, so the serial8250
suspend/resume functions should only be applied to a real 8250 port.
Signed-off-by: NJingchang Lu <jingchang.lu@freescale.com>
Tested-by: NJoseph Lo <josephl@nvidia.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The struct uart_port.flags field is type upf_t, as are the matching
bit definitions. Change local mask variable to type upf_t.

Fixes sparse warnings:
drivers/tty/serial/serial_core.c:620:22: warning: invalid assignment: |=
drivers/tty/serial/serial_core.c:620:22:    left side has type unsigned int
drivers/tty/serial/serial_core.c:620:22:    right side has type restricted upf_t
drivers/tty/serial/serial_core.c:622:22: warning: invalid assignment: |=
drivers/tty/serial/serial_core.c:622:22:    left side has type unsigned int
drivers/tty/serial/serial_core.c:622:22:    right side has type restricted upf_t
drivers/tty/serial/serial_core.c:624:17: warning: restricted upf_t degrades to integer
drivers/tty/serial/serial_core.c:626:22: warning: invalid assignment: &=
drivers/tty/serial/serial_core.c:626:22:    left side has type unsigned int
drivers/tty/serial/serial_core.c:626:22:    right side has type restricted upf_t
drivers/tty/serial/serial_core.c:629:20: warning: restricted upf_t degrades to integer
drivers/tty/serial/serial_core.c:632:20: warning: restricted upf_t degrades to integer
drivers/tty/serial/serial_core.c:643:22: warning: invalid assignment: |=
drivers/tty/serial/serial_core.c:643:22:    left side has type unsigned int
drivers/tty/serial/serial_core.c:643:22:    right side has type restricted upf_t
drivers/tty/serial/serial_core.c:645:22: warning: invalid assignment: |=
drivers/tty/serial/serial_core.c:645:22:    left side has type unsigned int
drivers/tty/serial/serial_core.c:645:22:    right side has type restricted upf_t
drivers/tty/serial/serial_core.c:647:17: warning: restricted upf_t degrades to integer
drivers/tty/serial/serial_core.c:649:22: warning: invalid assignment: &=
drivers/tty/serial/serial_core.c:649:22:    left side has type unsigned int
drivers/tty/serial/serial_core.c:649:22:    right side has type restricted upf_t
drivers/tty/serial/serial_core.c:652:20: warning: restricted upf_t degrades to integer
drivers/tty/serial/serial_core.c:655:20: warning: restricted upf_t degrades to integer
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 299245a1,
serial: core: Privatize modem status enable flags, introduced
the upstat_t type and matching bit definitions. The purpose is to
produce sparse warnings if the wrong bit definitions are used
(by warning of implicit integer conversions).

Fix implicit conversion to integer return type from uart_cts_enabled()
and uart_dcd_enabled().

Fixes the following sparse warnings:
drivers/tty/serial/serial_core.c:63:30: warning: incorrect type in return expression (different base types)
drivers/tty/serial/serial_core.c:63:30:    expected int
drivers/tty/serial/serial_core.c:63:30:    got restricted upstat_t
include/linux/serial_core.h:364:30: warning: incorrect type in return expression (different base types)
include/linux/serial_core.h:364:30:    expected bool
include/linux/serial_core.h:364:30:    got restricted upstat_t
include/linux/serial_core.h:364:30: warning: incorrect type in return expression (different base types)
include/linux/serial_core.h:364:30:    expected bool
include/linux/serial_core.h:364:30:    got restricted upstat_t
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The atmel serial driver uses dmaengine APIs but never included the dmaengine
header as it was getting inculded thru one of driver headers.

commit 3d588f83 - "dmaengine: dw: split
dma-dw.h to platform and private parts" broke this as it moved headers
around.  Fix this by doing the right thing to include the dmaengine header
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Fixes: 08f738be (serial: at91: add tx dma support)
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The drivers should use dmaengine_terminate_all() API instead of
accessing the device_control which will be deprecated soon
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

This reverts commit a86713b1.

Kevin Hilman writes:

	Multiple boot failures on ARM[1] were bisected down to this
	patch.

	How was this patch tested, and on which platforms?

	Also, the changelog states that this should be done only for
	UART_CAP_SLEEP, but the patch does it for every UART.

	Greg, I suggest this patch be dropped from tty-next until it has
	been better described and tested.

	[1] http://lists.linaro.org/pipermail/kernel-build-reports/2014-October/005550.htmlReported-by: NKevin Hilman <khilman@kernel.org>
Cc: Sudhir Sreedharan <ssreedharan@mvista.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for DT based and command line based early console on platforms
with the msm serial hardware.

Cc: Rob Herring <robh@kernel.org>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For console devices having UART_CAP_SLEEP capability, the uart_pm_state has
to be initialized to UART_PM_STATE_ON. Otherwise the LCR regiser values
are reinitialized when uart_change_pm is called from uart_configure_port.
Signed-off-by: NSudhir Sreedharan <ssreedharan@mvista.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 08177ece ("serial: asc: Adopt readl_/writel_relaxed()) is
regressing the m68k allmodconfig build. This is due to the unconditional
use of readl_relaxed() which, although documented, does not currently
exist for m68k.

This is trivially fixable for st-asc because we can just update the
asc_in() accessor to make this conditional.
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds PM suspend/resume support for the of-serial driver
to provide power management support on devices attatched to it.
Signed-off-by: NJingchang Lu <jingchang.lu@freescale.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It should not be used together with Auto Flow Control, and
Auto Flow Control is always enabled on Baytrail.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add earlycon support for the cadence serial port.
This is based on recent patches:
"tty/serial: pl011: add generic earlycon support"
(sha1: 0d3c673e)
"tty/serial: add arm/arm64 semihosting earlycon"
(sha1: d50d7269)
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The wait_event() makes the application hang for ever in the following case:
 [1] the hardware flow control is enabled.
 [2] the other end (or the remote end) is terminated, and the TX is still
     waiting for the hardware flow control signal to become asserted.

This patch fixes it by changing the wait_event to wait_event_interruptible.
Signed-off-by: NHuang Shijie <shijie8@gmail.com>
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the uart port is suspending, the RX data is useless.
So in this case, we can terminate the RX DMA right now.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

when the 'CTSC' bit is negated. 'CTS' has no function when 'CTSC' is asserted.
0: The CTS pin is high (inactive)
1: The CTS pin is low (active)

For throttle, it needs to clear 'CTS' and 'CTSC' bits.
For unthrottle, it needs to enable 'CTS' and 'CTSC' bits.

The patch just fix the issue.
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NHuang Shijie <shijie8@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Quark X1000 contains two designware derived 8250 serial ports.
Each port has a unique PCI configuration space consisting of
BAR0:UART BAR1:DMA respectively.

Unlike the standard 8250 the register width is 32 bits for RHR,IER etc
The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a
bitrate of up to about 2.76 megabits per second.

This patch enables standard 8250 mode
Signed-off-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To determine the correct divisor, we need to know the difference between
the desired baud rate and the actual baud rate. The calculation for this
difference is implemented twice within omap_serial_baud_is_mode16().
Pull out the calculation for easier maintenance.

While at it, remove the CamelCasing from the variable names.
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
calculated n values in serial_omap_is_baud_mode16() may become 0. This
causes a division by zero when calculating the difference between
calculated and desired baud rates. To prevent this, cap the n13 and n16
values on 1.

Division by zero in kernel.
[<c00132e0>] (unwind_backtrace) from [<c00112ec>] (show_stack+0x10/0x14)
[<c00112ec>] (show_stack) from [<c01ed7bc>] (Ldiv0+0x8/0x10)
[<c01ed7bc>] (Ldiv0) from [<c023805c>] (serial_omap_baud_is_mode16+0x4c/0x68)
[<c023805c>] (serial_omap_baud_is_mode16) from [<c02396b4>] (serial_omap_set_termios+0x90/0x8d8)
[<c02396b4>] (serial_omap_set_termios) from [<c0230a0c>] (uart_change_speed+0xa4/0xa8)
[<c0230a0c>] (uart_change_speed) from [<c0231798>] (uart_set_termios+0xa0/0x1fc)
[<c0231798>] (uart_set_termios) from [<c022bb44>] (tty_set_termios+0x248/0x2c0)
[<c022bb44>] (tty_set_termios) from [<c022c17c>] (set_termios+0x248/0x29c)
[<c022c17c>] (set_termios) from [<c022c3e4>] (tty_mode_ioctl+0x1c8/0x4e8)
[<c022c3e4>] (tty_mode_ioctl) from [<c0227e70>] (tty_ioctl+0xa94/0xb18)
[<c0227e70>] (tty_ioctl) from [<c00cf45c>] (do_vfs_ioctl+0x4a0/0x560)
[<c00cf45c>] (do_vfs_ioctl) from [<c00cf568>] (SyS_ioctl+0x4c/0x74)
[<c00cf568>] (SyS_ioctl) from [<c000e480>] (ret_fast_syscall+0x0/0x30)
Signed-off-by: NFrans Klaver <frans.klaver@xsens.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

serial8250_do_startup() adds UART_IER_RDI and UART_IER_RLSI to ier.
serial8250_stop_rx() should remove both.
This is what the serial-omap driver has been doing and is now moved to
the 8250-core since it does no look to be *that* omap specific.
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NTony Lindgren <tony@atomide.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Tony noticed that the old omap-serial driver picked the uart "number"
based on the hint given from device tree or platform device's id.
The 8250 based omap driver doesn't do this because the core code does
not honour the ->line argument which is passed by the driver.

This patch aims to keep the same behaviour as with omap-serial. The
function will first try to use the line suggested ->line argument and
then fallback to the old strategy in case the port is taken.

That means the the third uart will always be ttyS2 even if the previous
two have not been enabled in DT.
Reviewed-by: NTony Lindgren <tony@atomide.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The serial8250_do_startup() function unconditionally clears the
interrupts and for that it reads from the RX-FIFO without checking if
there is a byte in the FIFO or not. This works fine on OMAP4+ HW like
AM335x or DRA7.
OMAP3630 ES1.1 (which means probably all OMAP3 and earlier) does not like
this:

|Unhandled fault: external abort on non-linefetch (0x1028) at 0xfb020000
|Internal error: : 1028 [#1] ARM
|Modules linked in:
|CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-00022-g7edcb57-dirty #1213
|task: de0572c0 ti: de058000 task.ti: de058000
|PC is at mem32_serial_in+0xc/0x1c
|LR is at serial8250_do_startup+0x220/0x85c
|Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
|Control: 10c5387d  Table: 80004019  DAC: 00000015
|[<c03051d4>] (mem32_serial_in) from [<c0307fe8>] (serial8250_do_startup+0x220/0x85c)
|[<c0307fe8>] (serial8250_do_startup) from [<c0309e00>] (omap_8250_startup+0x5c/0xe0)
|[<c0309e00>] (omap_8250_startup) from [<c030863c>] (serial8250_startup+0x18/0x2c)
|[<c030863c>] (serial8250_startup) from [<c030394c>] (uart_startup+0x78/0x1d8)
|[<c030394c>] (uart_startup) from [<c0304678>] (uart_open+0xe8/0x114)
|[<c0304678>] (uart_open) from [<c02e9e10>] (tty_open+0x1a8/0x5a4)
Reviewed-by: NTony Lindgren <tony@atomide.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

While comparing the OMAP-serial and the 8250 part of this I noticed that
the latter does not use run time-pm. Here are the pieces. It is
basically a get before first register access and a last_busy + put after
last access. This has to be enabled from userland _and_ UART_CAP_RPM is
required for this.
The runtime PM can usually work transparently in the background however
there is one exception to this: After serial8250_tx_chars() completes
there still may be unsent bytes in the FIFO (depending on CPU speed vs
baud rate + flow control). Even if the TTY-buffer is empty we do not
want RPM to disable the device because it won't send the remaining
bytes. Instead we leave serial8250_tx_chars() with RPM enabled and wait
for the FIFO empty interrupt. Once we enter serial8250_tx_chars() with
an empty buffer we know that the FIFO is empty and since we are not going
to send anything, we can disable the device.
That xchg() is to ensure that serial8250_tx_chars() can be called
multiple times and only the first invocation will actually invoke the
runtime PM function. So that the last invocation of __stop_tx() will
disable runtime pm.

NOTE: do not enable RPM on the device unless you know what you do! If
the device goes idle, it won't be woken up by incomming RX data _unless_
there is a wakeup irq configured which is usually the RX pin configure
for wakeup via the reset module. The RX activity will then wake up the
device from idle. However the first character is garbage and lost. The
following bytes will be received once the device is up in time. On the
beagle board xm (omap3) it takes approx 13ms from the first wakeup byte
until the first byte that is received properly if the device was in
core-off.

v5…v8:
	- drop RPM from serial8250_set_mctrl() it will be used in
	  restore path which already has RPM active and holds
	  dev->power.lock
v4…v5:
	- add a wrapper around rpm function and introduce UART_CAP_RPM
	  to ensure RPM put is invoked after the TX FIFO is empty.
v3…v4:
	- added runtime to the console code
	- removed device_may_wakeup() from serial8250_set_sleep()

Cc: mika.westerberg@linux.intel.com
Reviewed-by: NTony Lindgren <tony@atomide.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The OMAP UART provides support for HW assisted flow control. What is
missing is the support to throttle / unthrottle callbacks which are used
by the omap-serial driver at the moment.
This patch adds the callbacks. It should be safe to add them since they
are only invoked from the serial_core (uart_throttle()) if the feature
flags are set.
Reviewed-by: NTony Lindgren <tony@atomide.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

uart_set_termios() is called with interrupts enabled; no need to
save and restore the interrupt state when taking the uart port lock.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 64851636,
serial: bfin-uart: Remove ASYNC_CTS_FLOW flag for hardware automatic CTS,
open-codes uart_handle_cts_change() when CONFIG_SERIAL_BFIN_HARD_CTSRTS
to skip start and stop tx.

But the CTS interrupt handler _still_ calls uart_handle_cts_change();
only call uart_handle_cts_change() if !CONFIG_SERIAL_BFIN_HARD_CTSRTS.

cc: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

tty->hw_stopped is not used by the tty core and is thread-unsafe;
hw_stopped is a member of a bitfield whose fields are updated
non-atomically and no lock is suitable for serializing updates.

Replace serial core usage of tty->hw_stopped with uport->hw_stopped.
Use int storage which works around Alpha EV4/5 non-atomic byte storage,
since uart_port uses different locks to protect certain fields within the
structure.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The serial core uses the tty port flags, ASYNC_CTS_FLOW and
ASYNC_CD_CHECK, to track whether CTS and DCD changes should be
ignored or handled. However, the tty port flags are not safe for
atomic bit operations and no lock provides serialized updates.

Introduce the struct uart_port status field to track CTS and DCD
enable states, and serialize access with uart port lock. Substitute
uart_cts_enabled() helper for tty_port_cts_enabled().
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The serial core provides two helper functions, uart_handle_dcd_change()
and uart_handle_cts_change(), for UART drivers to use at interrupt
time. The serial core expects the UART driver to hold the uart port lock
when calling these helpers to prevent state corruption.

If lockdep enabled, trigger a warning if the uart port lock is not held
when calling these helper functions.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We are trying to smoke out the use of the return value from
gpiochip_remove() from the kernel, this has been missed.
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This patch fixes COMPILE_TEST build of serial_mctrl_gpio module for
architectures with custom termios.h header.

sparc64:allmodconfig:

In file included from drivers/tty/serial/serial_mctrl_gpio.c:21:0:
include/uapi/asm-generic/termios.h:22:8: error: redefinition of 'struct termio'
./arch/sparc/include/uapi/asm/termbits.h:16:8: note: originally defined here
make[3]: *** [drivers/tty/serial/serial_mctrl_gpio.o] Error 1
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

this remove all reference to gpio_remove retval in all driver
except pinctrl and gpio. the same thing is done for gpio and
pinctrl in two different patches.
Signed-off-by: NAbdoulaye Berthe <berthe.ab@gmail.com>
Acked-by: NMichael Büsch <m@bues.ch>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NMauro Carvalho Chehab <m.chehab@samsung.com>
Acked-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

Add new PCI IDs to cover newer Intel SoCs such as Braswell.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

That field has been deprecated in favour of getting the necessary information
from ACPI or DT.

However, we still need to deal systems that are PCI only (no ACPI to back up)
like Intel Bay Trail. In order to support such systems, we explicitly bind
setup() to the appropriate DMA filter function and its corresponding parameter.
Then when serial8250_request_dma() doesn't find the channel via ACPI or DT, it
falls back to use the given filter function.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The device has a highspeed register which influences the calcualtion
of the divisor. The chip lacks support for some baudrates. When requested,
we set the divisor to the next smaller baudrate and adjust the c_cflag
accordingly.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The architectures supported by this driver, arm and sh, have expensive
implementations of writel(), reliant on spin locks and explicit L2 cache
management. These architectures provide a cheaper writel_relaxed() which
is much better suited to peripherals that do not perform DMA. The
situation with readl()/readl_relaxed()is similar although less acute.

This driver does not use DMA and will be more power efficient and more
robust (due to absence of spin locks during console I/O) if it uses the
relaxed variants.

The driver supports COMPILE_TEST and therefore falls back to writel()
when writel_relaxed() does not exist.
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Acked-by: NSrinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: kernel@stlinux.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The patch fixes the following build error of CLPS711X serial driver for
targets without GPIOLIB support:

>> drivers/tty/serial/serial_mctrl_gpio.c:44:6: error: redefinition of 'mctrl_gpio_set'
  void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
      ^
  In file included from drivers/tty/serial/serial_mctrl_gpio.c:23:0:
  drivers/tty/serial/serial_mctrl_gpio.h:80:6: note: previous definition of 'mctrl_gpio_set' was here
  void mctrl_gpio_set(struct mctrl_gpios *gpios, unsigned int mctrl)
      ^
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit: e676253b [3/21] serial/8250: Add
support for RS485 IOCTLs, adds a building error on arch m32r.

All error/warnings:

   drivers/tty/serial/8250/8250_core.c: In function 'serial8250_ioctl':
>> drivers/tty/serial/8250/8250_core.c:2859:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
      if (copy_from_user(&rs485_config, (void __user *)arg,
      ^
>> drivers/tty/serial/8250/8250_core.c:2871:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
      if (copy_to_user((void __user *)arg, &up->rs485,
      ^
   cc1: some warnings being treated as errors
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tx_empty() callback currently checks the TXEMPTY bit in the interrupt
status register to decided whether the FIFO should be reported as empty or
not. The bit in this register gets set when the FIFO state transitions from
non-empty to empty but is cleared again in the interrupt handler. This means
it is not suitable to be used to decided whether the FIFO is currently empty
or not. Instead use the TXEMPTY bit from the status register which will be
set as long as the FIFO is empty.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In set_termios(), interrupts where not disabled if UART_ENABLE_MS() was
false.

Tested on at91sam9g35.
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # >= 3.16
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>