The registers for the Samsung S3C serial port are currently defined in
the platform specific arch/arm/plat-samsung/include/plat/regs-serial.h
file, which is not visible to multiplatform capable drivers.

Unfortunately, it is not possible to move the file into a more local
place as we should normally try to, because the same registers
may be used in one of four places:

* In the driver itself
* In platform-independent ARM code for early debug output
* In platform_data definitions
* In the Samsung platform power management code

I have also found no way to logically split out a platform_data
file, other than possibly move everything into
include/linux/platform_data, which also felt wrong. The only
part of this file that makes sense to keep specific to the s3c24xx
platform are the virtual and physical addresses defined here,
which are needed in no other location.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With the common clock interface, there is no way to provide the
"clock_source" sysfs attribute for the samsung serial ports. Given that
this file was purely informational and had fixed contents, we have reason
to believe that no user space programs were relying on it.

The sysfs file is not documented in the ABI docs.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The no_console_suspend option allows the console to write to the UART
during early resume, before the serial port itself is resumed. Such
writes hang indefinitely waiting for TX ready.

This adds a check to the console putchar function to drop characters
instead of hanging if the port hasn't been initialized. That way, we
can use no_console_suspend without risk of hanging.
Signed-off-by: NMichael Spang <spang@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This closes a window where the system may hang in resume as soon as the
UART interrupt is enabled and before the mask is restored. The hang occurs
because the driver can't handle IRQs it thinks are masked.
Signed-off-by: NMichael Spang <spang@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since the interrupt mask register is not preserved across system suspend
and it defaults to all interrupts enabled, it is not enough to disable
UART interrupt.

This patch adds free_irq to port shutdown and mask setting to port
startup to handle IRQ disabling in a suspend-friendly way. In addition,
a bug caused by multiple request_irq calls in port startup callback is
fixed.
Signed-off-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This eliminates having an #ifdef returning NULL for the case
when OF is disabled.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The address S3C_VA_UART is a statically ioremapped address. The driver
should not be using this. Instead, the driver should setup a mapping
during probe.

Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The setting of uart line control configuration in s3c24xx_serial_resetport
is can be removed since the 'set_termios' call will overwrite any ULCON
register setting which s3c24xx_serial_resetport does.
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NThomas Abraham <thomas.ab@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Until now only the Exynos SoCs could use the serial driver via the
device tree. This patch adds compatible properties for the other
supported SoCs as well.

Tested on a s3c2416 based machine.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Certain tty line discipline implementations such slip and bluetooth hci invoke
the serial core uart_write() api in their write_wakeup callback. This leads to
a soft lockup with samsung serial driver since the uart port lock is taken in
the driver's interrupt handler and uart_write() attempts to take the same lock
again.

Fix this issue by releasing the uart port lock before the call to
uart_write_wakeup() in the tx handler. Also move the spin-lock/unlock sequence
from s3c64xx_serial_handle_irq() function into the tx and rx irq handlers so
that this change is applicable to s3c24xx platforms as well.
Reported-by: NKyungmin Park <kyungmin.park@samsung.com>
Reported-by: NHyeonkook Kim <hk619.kim@samsung.com>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds support for EXYNOS5440 SoC which is including
ARM Cortex-A15 Quad cores.
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: NDavid Brown <davidb@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Tony Prisk <linux@prisktech.co.nz>
Acked-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare
calls as required by common clock framework.
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The following patch allows users to use KGDB over serial console on
board based on Samsung SOC. It has been tested on a board using
exynos5.

[dianders: changed poll to return NO_POLL_CHAR, which appears to
fix 'help' in kgdb; also updated commit message]
Signed-off-by: NJulien Pichon <pichon.jln@gmail.com>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Return the value returned by the failing function instead
of -1 (which does not convey the right error information).

Fixes the following smatch warning:
drivers/tty/serial/samsung.c:1687 s3c24xx_serial_modinit() info:
why not propagate 'ret' from uart_register_driver() instead of -1?
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes the following errors and warnings:
ERROR: trailing whitespace
ERROR: return is not a function, parentheses are not required
WARNING: suspect code indent for conditional statements (32, 36)
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Silences checkpatch warnings regarding use of printks.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

port->baudclk_rate should be compared to the rate of port->baudclk,
because port->baudclk_rate was assigned as the rate of port->baudclk previously.
So to check that the current baudclk rate is same as previous rate,
the target of comparison sholud be the rate of port->baudclk.
Signed-off-by: NJun-Ho, Yoon <junho78.yoon@samsung.com>
Signed-off-by: NKyoungil Kim <ki0351.kim@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When priting the serial clock source, if clock source name is null,
kernel reference NULL point.
Signed-off-by: NKeyYoung Park <keyyoung.park@samsung.com>
Signed-off-by: NHuisung Kang <hs1218.kang@samsung.com>
Signed-off-by: NKyoungil Kim <ki0351.kim@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

port->baudclk_rate should be compared to the rate of port->baudclk,
because port->baudclk_rate was assigned as the rate of port->baudclk previously.
So to check that the current baudclk rate is same as previous rate,
the target of comparison sholud be the rate of port->baudclk.
Signed-off-by: NJun-Ho, Yoon <junho78.yoon@samsung.com>
Signed-off-by: NKyoungil Kim <ki0351.kim@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NKyoungil Kim <ki0351.kim@samsung.com>
Suggested-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix omission initialize ulcon in s3c24xx_serial_resetport(),
reset port function in drivers/tty/serial/samsung.c. It has
been happened from commit 0dfb3b41("serial: samsung: merge
all SoC specific port reset functions")
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: stable <stable@vger.kernel.org> [3.3]
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Without that fix machines having a s3c2442 CPU have something
  like that in dmesg:
    samsung-uart s3c2440-uart.0: could not find driver data
    samsung-uart s3c2440-uart.1: could not find driver data
    samsung-uart s3c2440-uart.2: could not find driver data
  And serial is never initialized.

The previous log was obtained trough early printk on the gta02
  machine.
Signed-off-by: NDenis 'GNUtoo' Carikli <GNUtoo@no-log.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Cc: Thomas Abraham <thomas.abraham@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This should be added for EXYNOS4212 and EXYNOS4412 SoCs.

Cc: Thomas Abraham <thomas.abraham@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

exynos4120_serial_drv_data is only defined when building with support
for Exynos4210 so use the already provided define to ensure that we
don't reference it when building for other SoCs.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
[kgene.kim@samsung.com: Fixed build warning]
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

Add device tree based discovery support for Samsung's uart controller.

Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

With reset port, set clock and get clock functions in SoC specific extentions
being removed, only the driver probe is left over in these extensions. The
probe function itself can be merged into one and moved into the samsung common
serial driver. With driver probe also moved, all the SoC specific extentions
are no longer required and they are deleted.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

The port reset function in each of the platform specific extension performs
the same operations and hence all the reset port functions can be merged into
one and moved into the common samsung uart driver. The SoC specific port reset
functions are removed from SoC extensions.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

Instead of using clock names supplied in platform data, use a generic
clock name 'clk_uart_baud' to look up clocks. The platform code should
register clocks with the name 'clk_uart_baud' which can be used by the
baud rate generator. The clock lookup and selection of the best clock
as baud rate clock is reworked.

Platform code can specify the clocks that can be used as source for the
baud clock (as supported previously by passing names of clocks). A new
member is added to the platform data 'clk_sel' which holds a bit-field
value with each bit representing a baud source clock. If a bit at any
bit position is set, that clock is looked up to participate in the
selection of the baud clock source.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

s3c2440 uses fclk/n (fclk divided by n) clock as one of the possible clocks used
to generate the baud rate clock. The divider 'n' in this case can be logically
represented outside of the uart controller.

This patch creates a new clock by name "fclk_n" for s3c2440 based platforms to
represent the fclk/n clock in the platform code. This clock provides a get_rate
callback that checks the UCON0/1/2 registers to determine the clock rate. The
samsung uart driver would receive the "fclk_n" clock name as one of the possible
baud rate clock options and the driver need not determine clock rate of fclk/n.

Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

Add a pointer to the location of the platform data in the driver's private
data. When instantiated using device tree, pdev->dev->platform_data does not
necessarily point to a valid instance of platform data. The platform data
pointer in the driver's private data could be set to pdev->dev->platform_data
or platform data instance created from device tree.

Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

s3c64xx and later SoC's include the interrupt mask and pending registers
in the uart controller, unlike the s3c24xx SoC's which have these registers
in the interrupt controller. When the mask and pending registers are part
of the uart controller, a unified interrupt handler can handle the tx/rx
interrupt. With this, the static reservation of interrupt numbers for the
uart tx/rx/err interrupts in the linux irq space is not required and
simplifies adding device tree support.
Suggested-by: NGrant Likely <grant.likely@secretlab.ca>
CC: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: NThomas Abraham <thomas.abraham@linaro.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/tty/serial/samsung.c: In function 's3c24xx_serial_init':
drivers/tty/serial/samsung.c:1237: error: lvalue required as unary '&' operand

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Uart port is registered as a console during the driver's probe.
So explict registration of console with console_initcall is
removed.
Signed-off-by: NThomas Abraham <thomas.ab@samsung.com>
[kgene.kim@samsung.com: removed changes of s3c2400 and s3c24a0]
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

In s3c24xx_serial_console_setup function, if the uart port that is
being setup as a console has not been initialized, an error can be
returned instead of using uart port 0 as the default console port.
The uart port that was intended to be used as a console could be
initialized at a later point during boot and then registered as a
console. This will avoid using uart port 0 as a unintended console
port.
Signed-off-by: NThomas Abraham <thomas.ab@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

This patch "modernize" tty/serial/samsung.c to use non-legacy code for
suspend/resume.
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungMin Park <kyungmin.park@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>