As part of an SMP cleanliness pass over UML, I consted a bunch of
structures in order to not have to document their locking.  One of these
structures was a struct tty_operations.  In order to const it in UML
without introducing compiler complaints, the declaration of
tty_set_operations needs to be changed, and then all of its callers need to
be fixed.

This patch declares all struct tty_operations in the tree as const.  In all
cases, they are static and used only as input to tty_set_operations.  As an
extra check, I ran an i386 allyesconfig build which produced no extra
warnings.

53 drivers are affected.  I checked the history of a bunch of them, and in
most cases, there have been only a handful of maintenance changes in the
last six months.  serial_core.c was the busiest one that I looked at.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Hack uart_suspend_port() and uart_resume_port() so that serial console
ports are not suspended if CONFIG_DISABLE_CONSOLE_SUSPEND is set.

This makes it possible to debug the suspend and resume routines of all
device drivers as well as the lowest-level swsusp code with the help of the
serial console.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

uart_match_port() always fails with UPIO_MEM32, UPIO_AU, and UPIO_TSI cases.
Since they match to the memory mapped UARTs, they should be handled just like
UPIO_MEM case.
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The following patch gets rid of CONFIG_TSI108_BRIDGE.  I add UPIO_TSI to
handle IIR and IER register in serial_in and serial_out.

(1) the reason to rewrite serial_in:

    TSI108 rev Z1 version ERRATA.  Reading the UART's Interrupt
    Identification Register (IIR) clears the Transmit Holding Register
    Empty (THRE) and Transmit buffer Empty (TEMP) interrupts even if they
    are not enabled in the Interrupt Enable Register (IER).  This leads to
    loss of the interrupts.  Interrupts are not cleared when reading UART
    registers as 32-bit word.

(2) the reason to rewrite serial_out:

    Check for UART_IER_UUE bit in the autoconfig routine.  This section
    of autoconfig is excluded for Tsi108/109 because bits 7 and 6 are
    reserved for internal use.  They are R/W bits.  In addition to
    incorrect identification, changing these bits (from 00) will make
    Tsi108/109 UART non-functional.
Signed-off-by: NRoy Zang <tie-fei.zang@freescale.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Teach special (dual-initialized) locking code to the lock validator.  Has no
effect on non-lockdep kernels.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some UARTs have more than 255 bytes of FIFO, which can't be
represented by an unsigned char.  Change the kernel's internal
structure to be an unsigned int, but still export an unsigned char
via the TIOCGSERIAL ioctl.  If the TIOCSSERIAL ioctl provides a
fifo size of 0, assume this means "don't change" otherwise we'll
corrupt the larger fifo sizes.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

I've always found this flag confusing.  Now that devfs is no longer around, it
has been renamed, and the documentation for when this flag should be used has
been updated.

Also fixes all drivers that use this flag.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Also fixes all serial drivers.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Patch from Andrew Victor

The serial_core already manages the power state of the UARTs, and
therefore it shouldn't suspend a UART which was previously suspended.

This patch modifies serial_core only call the UART-specific
power-management function if the PM state is actually changing.
Signed-off-by: NAndrew Victor <andrew@sanpeople.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The locking for the uart_port is over complicated, and can be
simplified if we introduce a flag to indicate that a port is "dead"
and will be removed.

This also helps the validator because it removes a case of non-nested
unlock ordering.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Glen Turner reported that writing LFCR rather than the more
traditional CRLF causes issues with some terminals.

Since this aflicts many serial drivers, extract the common code
to a library function (uart_console_write) and arrange for each
driver to supply a "putchar" function.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We're presently getting oopses because Bluetooth (and possibly other) drivers
are calling core functions after things have been shut down.

So rather than oopsing, let's drop a warning then take avoiding action, so the
machine survives.  Once all the sub-drivers are fixed up we can remove the
take-avoiding-action part.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It seems serial_core intend to initialize port->lock just once for each
ports.  This is done in uart_set_options() for console, and in
uart_add_one_port() for other ports.  But there is a case the port->lock is
not initialized by serial_core.  If the setup function for the console was
failed, it will not call uart_set_options() but the port is marked as
console (uart_console(port) returns 1).  It can happen if console was PCI
port which can not detected at the time of register_console.

This patch is to initialize port->lock for such console port.  With this
change, most of spin_lock_init() (some of them are labeled "Temporary
fix.") in low-level serial drivers can be omitted.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Same reasoning as commit 747c8a55
but this time we're making uart_port flags a bitwise type - not
all of these flags correspond with the old ASYNC_ flags, so there
is the possibility for bugs if the wrong ASYNC_* constants are
used.  Always use UPF_* constants for uart_port->flags.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

No one should write to the port->ops structure, so make it constant.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

semaphore to mutex conversion.

the conversion was generated via scripts, and the result was validated
automatically via a script as well.

build and boot tested.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Turn several drivers/serial/ semaphores-used-as-mutex into mutexes
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Jim Alexander reported a problem where "if one calls open() in
blocking mode with CLOCAL off, the 8250.c driver under the 2.6
kernel (or at least 2.6.8 and 2.6.10) does not wake up the
blocked process when DCD is asserted."

Fix this by enabling modem status interrupts immediately before
we read the carrier detect status.

Thanks to Jim for reporting the problem and testing the fix.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The function uart_match_port() incorrectly compares the ioremap'd
virtual addresses of ports instead of the physical address to find
duplicate ports for MMIO based UARTs. This fixes it.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch marks a few serial data structures const, moving them to
.rodata where they won't false-share cachelines with things that get
written to.
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If we fail to re-startup a serial port on resume, shut it down
immediately and mark it as an error condition.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The offsets of the registers are in a different place, and
some parts cannot handle a full set of modem control signals.
Signed-off-by: NPantelis Antoniou <pantelis@embeddedalley.ocm>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Folk seem to get confused when they see two or more ttyS0 ports
appearing at boot time.  One comes from the legacy table, and
one from PNP.

Hence, display the bus ID of the device which supplied the port.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch fixes an issue reported by Coverity in serial/serial_core.c

Error reported: Variable "&((info)->tty)->flags" tracked as NULL was passed to a
function that dereferences it.

The later statements in the function assumes 'info->tty != NULL', so this
check is not necessary.  Probably a 'BUG_ON(info->tty == NULL)' can be added.

Signed-off-by: Jayachandran C. <c.jayachandran at gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Pre-format the IO part of the ttyS printks, and prefix them with
KERN_INFO to avoid bootsplash corruption.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Sascha Hauer

This patch adds support for setting and getting RTS / CTS via
set_mtctrl / get_mctrl functions.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Initialise the spinlock for port being used by the console early, but
don't re-initialise it again later.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Fix bugme #4712: read the CTS status and set hw_stopped if CTS
is not active when opening the port and/or enabling CRTSCTS

Thanks to Stefan Wolff for spotting this problem.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch changes the way serial ports are locked when getting modem
status.  This change is necessary because we will need to atomically
read the modem status and take action depending on the CTS status.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!