Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

struct uart_omap_port and struct uart_omap_dma, and associated
definitions are private to the driver, so there's no point them sitting
in an include file under arch/arm.  Move them into the driver itself.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

irq_pending is never used, so let's remove it.  It seems to be  result
of a bad rebase of d37c6ceb (serial: omap: move uart_omap_port
definition to C file)
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The MCR TCRTLR bit can only be changed when ECB is set in the EFR.
Unfortunately, several places were trying to alter this bit while ECB
was clear:

- serial_omap_configure_xonxoff() was attempting to clear the bit after
  explicitly clearing the ECB bit.
- serial_omap_set_termios() was trying the same trick after setting the
  SCR, and when trying to change the TCR register when hardware flow
  control was enabled.

Fix this by ensuring that we always have ECB set whenever the TCRTLR bit
is changed.

Moreover, we start out by reading the EFR and MCR registers, which may
have indeterminent bit settings for the ECB and TCRTLR bits.  Ensure
that these bits always start off in a known state.

In order to avoid any undesired behaviour appearing through fixing this,
we also ensure that hardware assisted flow control is disabled while new
driver specific parts are not in place.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

c538d20c (and maybe previous commits) broke set_mctrl() by making
it only capable of setting bits in the MCR register.  This prevents
software controlled flow control and modem control line manipulation
via TIOCMSET/TIOCMBIC from working correctly.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There's no need to re-read EFR after we've recently written it; the
register is a configuration register which doesn't change its value
without us writing to it.  The last value which was written to this
register was up->efr.

Removing this re-reading avoids the possibility that we end up with
up->efr having unintended bits set, which should only be temporarily
set when accessing the enhanced features.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The SCD (special character detect) bit enables comparisons with XOFF2,
which we do not program.  As the XOFF2 character remains unprogrammed,
there's little point enabling this feature along with its associated
interrupt.  Remove this, and ensure that the SCD bit is cleared.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Nothing was clearing the UART_MCR_XONANY bit, so once the ixany
mode gets set, there's no possibility to disable it.  Clear this
bit when IXANY mode is cleared.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There is nothing which clears the auto RTS/CTS bits, so once hardware
flow control gets enabled, there's no possibility to disable it.
So, clear these bits when CRTSCTS is cleared.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add two callbacks for hardware assisted flow control; we need to know
when the tty layers want us to stop and restart due to their buffer
levels.

Call a driver specific throttle/unthrottle function if and only if the
driver indicates that it is using an enabled hardware assisted flow
control method, otherwise fall back to the non-hardware assisted
methods.
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Ports which are handling h/w flow control in hardware must not have
their RTS state altered depending on the tty's hardware-stopped state.
Avoid this additional logic when setting the termios state.
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Ports which are capable of handling s/w flow control in hardware to
know when the s/w flow control termios settings are changed.  Add a
flag to allow the low level serial drivers to indicate that they
support this, and these changes should be propagated to them.
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This is to make the following change more clear.
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This reverts commit 957ee727
(serial: omap: fix software flow control).

As Russell has pointed out, that commit isn't fixing
Software Flow Control at all, and it actually makes
it even more broken.

It was agreed to revert this commit and use Russell's
latest UART patches instead.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 2655a2c7 ("8250: use the 8250
register interface not the legacy one") forgot to fully switch one
instance of struct uart_port to struct uart_8250_port, causing the
following compile failure:

drivers/tty/serial/8250/8250_hp300.c: In function ‘hpdca_init_one’:
drivers/tty/serial/8250/8250_hp300.c:174: error: ‘uart’ undeclared (first use in this function)
drivers/tty/serial/8250/8250_hp300.c:174: error: (Each undeclared identifier is reported only once
drivers/tty/serial/8250/8250_hp300.c:174: error: for each function it appears in.)

This went unnoticed in -next, as CONFIG_HPDCA is not set to y by
allmodconfig.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Philip Blundell <philb@gnu.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It was already pointed out how to fix these cases before the offending
patches were merged, but unsurprisingly, that didn't happen. As this
change is entirely superfluous to begin with, simply shut things up by
casting everything away.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

It is possible to miss data when using the kdb pager.  The kdb pager
does not pay attention to the maximum column constraint of the screen
or serial terminal.  This result is not incrementing the shown lines
correctly and the pager will print more lines that fit on the screen.
Obviously that is less than useful when using a VGA console where you
cannot scroll back.

The pager will now look at the kdb_buffer string to see how many
characters are printed.  It might not be perfect considering you can
output ASCII that might move the cursor position, but it is a
substantially better approximation for viewing dmesg and trace logs.

This also means that the vt screen needs to set the kdb COLUMNS
variable.

Cc: <stable@vger.kernel.org>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

It is a common enough mistake for people to specify "kdb" when they
meant to type "kbd" that the kgdboc can just accept both since they
both mean the same thing anyway.  Specifically it is for the case
where you want kdb to be active on your graphics console + keyboard
(where kbd was the original abbreviation for keyboard).

With this change kgdboc will now accept either to mean the same thing:
   kgdboc=kbd
   kgdboc=kdb
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>

The build even tells you that this is a bad thing:

drivers/tty/serial/sccnxp: struct platform_device_id is 32 bytes.  The
last of 8 is:
0x73 0x63 0x36 0x38 0x36 0x39 0x32 0x00 0x00 0x00 0x00 0x00 0x00 0x00
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x54 0x0c 0x01 0x00
0x00 0x00 0x00 0x00
FATAL: drivers/tty/serial/sccnxp: struct platform_device_id is not
terminated with a NULL entry!

So fix this problem up before someone oopses their box when loading the
driver, as this breaks the build.

Cc: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Backend drivers shouldn't transistion to CLOSED unless the frontend is
CLOSED.  If a backend does transition to CLOSED too soon then the
frontend may not see the CLOSING state and will not properly shutdown.

So, treat an unexpected backend CLOSED state the same as CLOSING.
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

simplifies a bunch of callers...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

iterates through the opened files in given descriptor table,
calling a supplied function; we stop once non-zero is returned.
Callback gets struct file *, descriptor number and const void *
argument passed to iterator.  It is called with files->file_lock
held, so it is not allowed to block.

tty_io, netprio_cgroup and selinux flush_unauthorized_files()
converted to its use.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This special driver makes it possible to temporary use NMI debugger port
as a normal console by issuing 'nmi_console' command (assuming that the
port is attached to KGDB).

Unlike KDB's disable_nmi command, with this driver you are always able
to go back to the debugger using KGDB escape sequence ($3#33).  This is
because this console driver processes the input in NMI context, and thus
is able to intercept the magic sequence.

Note that since the console interprets input and uses polling
communication methods, for things like PPP it is still better to fully
detach debugger port from the KGDB NMI (i.e. disable_nmi), and use raw
console.

Usually, to enter the debugger one have to type the magic sequence, so
initially the kernel will print the following prompt on the NMI debugger
console:

	Type $3#33 to enter the debugger>

For convenience, there is a kgdb_fiq.knock kernel command line option,
when set to 0, this turns the special command to just a return key
press, so the kernel will be printing this:

	Hit <return> to enter the debugger>

This is more convenient for long debugging sessions, although it makes
nmi_console feature somewhat useless.

And for the cases when NMI connected to a dedicated button, the knocking
can be disabled altogether by setting kgdb_fiq.knock to -1.
Suggested-by: NColin Cross <ccross@android.com>
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Acked-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We need to quiesce interrupts in the poll_get_char routine, otherwise,
if used with KGDB NMI debugger, we'll keep reentering the NMI.

Quiescing interrupts is pretty straightforward, except for TXIM
interrupt. The interrupt has "ready to transmit" meaning, so it's
almost always raised, and the only way to silence it is to mask it. But
that's OK, ops->start_tx will unmask it.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The callback is used to initialize the hardware, nothing else should be
done, i.e. we should not request interrupts (but we can and do unmask
some of them, as they might be useful for NMI entry).

As a side-effect, the patch also fixes a division by zero[1] when booting
with kgdboc options specified (e.g. kgdboc=ttyAMA0,115200n8). The issue
happens because serial core calls set_termios callback, but the driver
doesn't know clock frequency, and thus cannot calculate proper baud rate
values.

[1]
WARNING: at drivers/tty/serial/serial_core.c:400 uart_get_baud_rate+0xe8/0x14c()
Modules linked in:
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c0020ae8>] (warn_slowpath_common+0x4c/0x64)
[<c0020ae8>] (warn_slowpath_common+0x4c/0x64) from [<c0020b1c>] (warn_slowpath_null+0x1c/0x24)
[<c0020b1c>] (warn_slowpath_null+0x1c/0x24) from [<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c)
[<c0185ed8>] (uart_get_baud_rate+0xe8/0x14c) from [<c0187078>] (pl011_set_termios+0x48/0x278)
[<c0187078>] (pl011_set_termios+0x48/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
---[ end trace 7d41c9186f342c40 ]---
Division by zero in kernel.
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10)
[<c014546c>] (Ldiv0+0x8/0x10) from [<c0187098>] (pl011_set_termios+0x68/0x278)
[<c0187098>] (pl011_set_termios+0x68/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
Division by zero in kernel.
[<c0018e50>] (unwind_backtrace+0x0/0xf0) from [<c014546c>] (Ldiv0+0x8/0x10)
[<c014546c>] (Ldiv0+0x8/0x10) from [<c0183a98>] (uart_update_timeout+0x4c/0x5c)
[<c0183a98>] (uart_update_timeout+0x4c/0x5c) from [<c01870f8>] (pl011_set_termios+0xc8/0x278)
[<c01870f8>] (pl011_set_termios+0xc8/0x278) from [<c01850b0>] (uart_set_options+0xe8/0x114)
[<c01850b0>] (uart_set_options+0xe8/0x114) from [<c0185de4>] (uart_poll_init+0xd4/0xe0)
[<c0185de4>] (uart_poll_init+0xd4/0xe0) from [<c016da8c>] (tty_find_polling_driver+0x100/0x17c)
[<c016da8c>] (tty_find_polling_driver+0x100/0x17c) from [<c0188538>] (configure_kgdboc+0xc8/0x1b8)
[<c0188538>] (configure_kgdboc+0xc8/0x1b8) from [<c00088a4>] (do_one_initcall+0x30/0x168)
[<c00088a4>] (do_one_initcall+0x30/0x168) from [<c033784c>] (do_basic_setup+0x94/0xc8)
[<c033784c>] (do_basic_setup+0x94/0xc8) from [<c03378e0>] (kernel_init+0x60/0xf4)
[<c03378e0>] (kernel_init+0x60/0xf4) from [<c00144a0>] (kernel_thread_exit+0x0/0x8)
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It was noticed that polling drivers (like KGDB) are not able to use
serial ports if the ports were not previously initialized via console.
I.e.  when booting with console=ttyAMA0 kgdboc=ttyAMA0, everything works
fine, but with console=ttyFOO kgdboc=ttyAMA0, the kgdboc doesn't work.

This is because we don't initialize the hardware. Calling ->startup() is
not an option, because drivers request interrupts there, and drivers
fail to handle situations when tty isn't opened with interrupts enabled.

So, we have to implement a new callback (actually, tty_ops already have
a similar callback), which does everything needed to initialize just the
hardware.
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This works around a few glitches in the ST version of the PL011
serial driver when using very high baud rates, as we do in the
Ux500: 3, 3.25, 4 and 4.05 Mbps.

Problem Observed/rootcause:

When using high baud-rates, and the baudrate*8 is getting close to
the provided clock frequency (so a division factor close to 1), when
using bursts of characters (so they are abutted), then it seems as if
there is not enough time to detect the beginning of the start-bit which
is a timing reference for the entire character, and thus the sampling
moment of character bits is moving towards the end of each bit, instead
of the middle.

Fix:
Increase slightly the RX baud rate of the UART above the theoretical
baudrate by 5%. This will definitely give more margin time to the
UART_RX to correctly sample the data at the middle of the bit period.

Also fix the ages old copy-paste error in the very stressed comment,
it's referencing the registers used in the PL010 driver rather than
the PL011 ones.
Signed-off-by: NGuillaume Jaunet <guillaume.jaunet@stericsson.com>
Signed-off-by: NChristophe Arnal <christophe.arnal@stericsson.com>
Signed-off-by: NMatthias Locher <matthias.locher@stericsson.com>
Signed-off-by: NRajanikanth HV <rajanikanth.hv@stericsson.com>
Cc: stable <stable@vger.kernel.org>
Cc: Bibek Basu <bibek.basu@stericsson.com>
Cc: Par-Gunnar Hjalmdahl <par-gunnar.hjalmdahl@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The kernel will handle IXON/IXOFF/IXANY in software if the hardware
doesn't do it.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
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>

MAXIDL is the timeout after which a receive buffer is closed when not full if
no more characters are received. We calculate it from the baudrate so that the
duration is always the same at standard rates: about 4ms. At 9600 bauds it gives
a timeout of 4 characters, which is the timeout on the 8250 UART.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

maxidl register was set to fifo size. There is no reason to set this
register to same value as fifo size. Setting it now to 0x10 by default
as in the UCC UART driver.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Setting the fifo to only 1 byte generates one interrupt every 1ms at 9600 bauds.
This is too much. This patch reduces the threshold to speeds below 2400 bauds
like in the 8250 UART driver.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes a desynchronisation problem with CPM UART driver on
Powerpc MPC8xx. The problem happens if data is received before the device
is open by the user application.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Apparently the same card model has two IDs, so this patch
complements the commit 39aced68
adding the missing one.
Signed-off-by: NFlavio Leitner <fbl@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch does the following
- In case of errors if there least one data character in the RX FIFO
read it otherwise it may stall the receiver.

This is recommended in the interrupt reset method in the table 23-246 of
the omap4 TRM.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Tested-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>