Intel MID UART quirks require already quite a bit of code
in 8250_pci.c. On new Intel platforms where it is used, the
integrated DMA engine no longer has its own PCI device, but
is instead configured from the UART's MMIO. That means we
will have to add even more code for handling just MID UARTs.

Instead of adding that to 8250_pci.c, splitting the support
of Intel MID UART into its own driver. Handling of the
integrated DMA engine becomes much simpler this way. Own
driver will also remove the need for things like specific
set_termios hooks for every board using this UART, and
simplify the handling of it in general.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for DT and command line based earlycon support for
lpuart and lpuart32 used on Freescale Vybrid and and QorIQ LS1021A
processors.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We recently got rid of some modular code in this driver and also
got rid of the unused ".remove" function at the same time.  Thierry
noted that it was however possible to force the remove through the
bind/unbind interface.

Since this is a console device used on 2005 vintage 74xx based
powerpc embedded targets, and is essentially always used in
conjunction with SERIAL_MPSC_CONSOLE=y -- there is no sane reason
anyone would ever want to unbind the builtin driver and lose the
console.  So we just explicitly block bind/unbind operations and
prevent root from shooting themselves in the foot.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-serial@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Waking the reader immediately upon receipt of TTY_BREAK or TTY_PARITY
chars has no effect on the outcome of read():
1. Only non-canonical/EXTPROC mode applies since canonical mode
   will not return data until a line termination is received anyway
2. EXTPROC mode - the reader will always be woken by the input worker
3. Non-canonical modes
   a. MIN == 0, TIME == 0
   b. MIN == 0, TIME > 0
   c. MIN > 0, TIME > 0
      minimum_to_wake is always 1 in these modes so the reader will always
      be woken by the input worker
   d. MIN > 0, TIME == 0
      although the reader will not be woken by the input worker unless the
      minimum data is received, the reader would not otherwise have
      returned the received data
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The statement after if should be indenteted. So fix this.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a misplaced bracket in atmel_init_rs485 which sets
rs485-rx-during-tx and rs485-enabled-at-boot-time only if
rs485-rts-delay is set in of.

This is clearly a bug, so fix it by moving the bracket to the proper
place.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Elen Song <elen.song@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty lock is strictly for serializing tty lifetime events
(open/close/hangup), and not for line discipline serialization.

The tty core already provides serialization of concurrent writes
to the same tty, and line discipline lifetime management (by ldisc
references), so pinning the tty via tty_lock() is unnecessary and
counter-productive; remove tty lock use.

However, the line discipline is responsible for serializing reads
(if required by the line discipline); add read_lock mutex to
serialize calls of r3964_read().
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty core provides read_wait waitqueue specifically for line
disciplines to wait readers; otherwise, the line discipline may
miss wakeups generated by the tty core.

NB: The tty core already provides serialization for the line discipline's
close() method, and guarantees no readers or writers will be using the
closing instance of the line discipline. Completely remove that wakeup.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With the removal of tty_wait_until_sent_from_close(), tty drivers
no longer wait during open for parallel closes to complete (instead,
the tty core waits before calling the driver open() method). Thus,
the close_wait waitqueue is no longer used for waiting.

Remove struct tty_port::close_wait.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since at least before 2.6.30, tty drivers that do not drop the tty lock
while closing cannot observe ASYNC_CLOSING set while holding the
tty lock; this includes the tty driver's open() and hangup() methods,
since the tty core calls these methods holding the tty lock.

For these drivers, waiting for ASYNC_CLOSING to clear while opening
is not required, since this condition cannot occur. Similarly, even
when the open() method drops and reacquires the tty lock after
blocking, ASYNC_CLOSING cannot be set (again, for drivers that
do not drop the tty lock while closing).

Now that tty port drivers no longer drop the tty lock while closing
(since 'tty: Remove tty_wait_until_sent_from_close()'), the same
conditions apply: waiting for ASYNC_CLOSING to clear while opening
is not required, nor is re-checking ASYNC_CLOSING after dropping and
reacquiring the tty lock while blocking (eg., in *_block_til_ready()).

Note: The ASYNC_CLOSING flag state is still maintained since several
bitrotting drivers use it for (dubious) other purposes.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

tty_wait_until_sent_from_close() drops the tty lock while waiting
for the tty driver to finish sending previously accepted data (ie.,
data remaining in its write buffer and transmit fifo).

tty_wait_until_sent_from_close() was added by commit a57a7bf3
("TTY: define tty_wait_until_sent_from_close") to prevent the entire
tty subsystem from being unable to open new ttys while waiting for
one tty to close while output drained.

However, since commit 0911261d ("tty: Don't take tty_mutex for tty
count changes"), holding a tty lock while closing does not prevent other
ttys from being opened/closed/hung up, but only prevents lifetime event
changes for the tty under lock.

Holding the tty lock while waiting for output to drain does prevent
parallel non-blocking opens (O_NONBLOCK) from advancing or returning
while the tty lock is held. However, all parallel opens _already_
block even if the tty lock is dropped while closing and the parallel
open advances. Blocking in open has been in mainline since at least 2.6.29
(see tty_port_block_til_ready(); note the test for O_NONBLOCK is _after_
the wait while ASYNC_CLOSING).

IOW, before this patch a non-blocking open will sleep anyway for the
_entire_ duration of a parallel hardware shutdown, and when it wakes, the
error return will cause a release of its tty, and it will restart with
a fresh attempt to open. Similarly with a blocking open that is already
waiting; when it's woken, the hardware shutdown has already completed
to ASYNC_INITIALIZED is not set, which forces a release and restart as
well.

So, holding the tty lock across the _entire_ close (which is what this
patch does), even while waiting for output to drain, is equivalent to
the current outcome wrt parallel opens.

Cc: Alan Cox <alan@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Karsten Keil <isdn@linux-pingi.de>
CC: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the tegra UART driver there are three places where the RX DMA buffer
is handled and pushed up to the tty layer. In all three instances the
same functions are called and so instead of duplicating the code in three
places, move this code to a new helper function and use this new function.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The serial-tegra driver always uses DMA and hence the driver always
allocates DMA channels. Therefore, the test to see if the RX DMA channel
is initialised in tegra_uart_stop_rx() is unnecessary and so remove
the test and the code that corresponds to the case where the RX DMA
channel is not initialised. Please note that the call to
tegra_uart_stop_rx() should always be before the call to
tegra_uart_shutdown() which will uninitialise the RX DMA channel.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some functions in the serial-tegra driver have unnecessary return
statements at the end of a void function and so remove them.
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 853a6997 ("serial: tegra: handle race condition on uart rx
side") attempted to fix a race condition between the RX end of
transmission interrupt and RX DMA completion callback. Despite this
fix there is still another case where these two paths can race and
result in duplicated data. The race condition is as follows:

1. DMA completion interrupt occurs and schedules tasklet to call DMA
   callback.
2. DMA callback for the UART driver starts to execute. This will copy
   the data from the DMA buffer and restart the DMA. This is done under
   uart port spinlock.
3. During the callback, UART interrupt is raised for end of receive. The
   UART ISR runs and waits to acquire port spinlock held by the DMA
   callback.
4. DMA callback gives up spinlock after copying the data, but before
   restarting DMA.
5. UART ISR acquires the spin lock and reads the same DMA buffer because
   DMA has not been restarted yet.

The release of the spinlock during the DMA callback was introduced by
commit 9b88748b ("tty: serial: tegra: drop uart_port->lock before
calling tty_flip_buffer_push()") to fix a spinlock lock-up issue when
calling tty_flip_buffer_push(). However, since then commit a9c3f68f
("tty: Fix low_latency BUG") migrated tty_flip_buffer_push() to always
use a workqueue, allowing tty_flip_buffer_push() to be called from
within atomic sections. Therefore, we can remove the unlocking of the
spinlock from the DMA callback and UART ISR and this will ensure that
the race condition no longer occurs.
Reported-by: NChristopher Freeman <cfreeman@nvidia.com>
Signed-off-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Clearing UART_MCR_RTS or UART_MCR_XONANY is unnecessary; these bits
are never set in the shadow mcr. The RTS clear is especially confusing.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The same serial hardware is present on LS2080A which is arm64, and
LS1021A which is arm32, so don't limit the workaround to PPC.

Unlike PPC which uses arch/powerpc/kernel/legacy_serial.c, the ARM
targets use drivers/tty/serial/of_serial.c, so add the handle_irq
override check there as well.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no need to hardcode the MEN_Z135_MEM_SIZE. The MCB subsystem
already knowns the size which is located in the chameleon table.
MCB parse the chameleon table to get the resources of each IP and provide
the mcb_request_mem function to get those resources.

Use mcb_request_mem to get the resources. This function also takes care of
the memory region naming allocated by the driver for each of the instances.
Signed-off-by: NAndreas Werner <andy@wernerandy.de>
Acked-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Turning on KVM and LPAE support on top of a multi_v7_defconfig will
produce a compiler warning in the Atmel serial driver:
drivers/tty/serial/atmel_serial.c: In function 'atmel_verify_port':
drivers/tty/serial/atmel_serial.c:2299:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  if ((void *)port->mapbase != ser->iomem_base)
      ^

Fix that by using the cast on the right hand side instead, as similar
code already does in other drivers.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This is mostly a hardening fix, given that write-only access to other
users' ttys is usually only given through setgid tty executables.
Signed-off-by: NJann Horn <jann@thejh.net>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds an entry to the uart_config table for PORT_RT2880
enabling rx/tx FIFOs.  The UART is actually a Palmchip BK-3103
which is found in several devices from Alchemy/RMI, Ralink, and
Sigma Designs.
Signed-off-by: NMans Rullgard <mans@mansr.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

UART controller is capable to perform transfers up to 4 Mbps.
Remove artificial 115.2 Kbps limitation.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add receive DMA support for UARTDM type of controllers.

Tested on APQ8064, which have UARTDM v1.3 and ADM DMA engine
and APQ8016, which have UARTDM v1.4 and BAM DMA engine.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add transmit DMA support for UARTDM type of controllers.

Tested on APQ8064, which have UARTDM v1.3 and ADM DMA engine
and APQ8016, which have UARTDM v1.4 and BAM DMA engine.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make function naming consistent across this driver.
Also rename msm_irq to msm_uart_irq. No functional changes.
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replaces (1 << x) with BIT(x) macro
Signed-off-by: NPramod Gurav <gpramod@codeaurora.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The bit masks for RFR_LEVEL1 and STALE_TIMEOUT_MSB values in MR1 and
IPR registers respectively are different for UART and UART_DM hardware
cores. We have been using UART core mask values for these. Add the same
for UART_DM core.

There is no bit setting as UART_IPR_RXSTALE_LAST for UART_DM core so do
it only for UART core.
Signed-off-by: NPramod Gurav <gpramod@codeaurora.org>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NIvan T. Ivanov <ivan.ivanov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If a wrong compatible flag in specified, the of_match_device
returning null.
Implemented check and if NULL then returning -ENODEV.
Signed-off-by: NSean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

They're used by only if CONFIG_PM is enabled, so enclose them
with proper ifdefs. Removes these warnings:

drivers/tty/serial/omap-serial.c:202:12: warning: 'serial_omap_get_context_loss_count' defined but not used [-Wunused-function]
drivers/tty/serial/omap-serial.c:213:13: warning: 'serial_omap_enable_wakeup' defined but not used [-Wunused-function]
Signed-off-by: NGuido Martínez <guido@vanguardiasur.com.ar>
Signed-off-by: NEzequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This ensures the dma mask that is supported by the driver is recorded
in the device structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

RX buffer is allocated from DMA coherent memory. Thus there is no need to call
DMA sync API for it.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move h/w reinit of serial console restore-from-suspend into
standalone helper function.

No functional change.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the UART clock is set slightly under 1.8432MHz, the 8250 driver
core doesn't permit the 115200 baud rate since it calculates the maximum
frequency to pass to uart_get_baud_rate by simply dividing the uart
clock by 16 which yields a value slightly under 115200, even though the
frequency is close enough for the UART to operate reliably.

Therefore add some tolerance in the calculation of the maximum baud
rate. 1% tolerance allows for marginally slower uart clk than nominal
without introducing transmission errors.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
[pjh: Forward-port & refactor original patch; change tolerance to 1%]
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are three natural ways in which devices may be wired to the system:
little endian (device receives correctly ordered bits of a word written
by little-endian CPU to its register, but big-endian CPU needs to swap
bytes of a word before writing it), big endian (same, but with big-endian
CPU in more favourable position) and native endian (CPU of either
endianness may do word-sized I/O without need for byteswapping).

Adding an option for native endianness allows using single kernel command
line for boards with native-endian serial ports on bi-endian
architectures. This goes in parallel with 'native-endian' DTS attribute.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These drivers doesn't claim the serial device to be wakeup source. Even
if it is, it needs to use enable_irq_wake or other related PM wakeup
APIs to enable it.

This patch removes yet another misuse of IRQF_NO_SUSPEND.

Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com>
Cc: Maxime Coquelin <maxime.coquelin@st.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kernel@stlinux.com
Cc: linux-serial@vger.kernel.org
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since the FD interrupt handler can discern spurious IRQs and it is
shared with timer interrupt, use IRQF_COND_SUSPEND instead of
IRQF_NO_SUSPEND.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function can return negative values.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576Signed-off-by: NAndrzej Hajda <a.hajda@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Acked-by: NTimur Tabi <timur@tabi.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.
Signed-off-by: NLuis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>