This patch adds xilinx uart loopback support by modifying the
cdns_uart_set_mctrl function to handle the switch to loopback mode.
After this patch, the loopback mode can be enabled/disabled by
setting/clearing the TIOCM_LOOP modem bit via TIOCMBIS/TIOCMBIC
ioctls respectively.
Signed-off-by: Yasir-Khan <yasir_khan@mentor.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

8250 UART DMA support was marked broken by default as it was not
possible to pause ongoing RX DMA transfer. Now that both SDMA and
EDMA can support pause operation for RX DMA transactions, don't set
rx_dma_broken to true by default. With this patch 8250_omap driver will
use DMA by default.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

UART uses as EDMA as dma engine on AM437x SoC and therefore, requires
OMAP_DMA_TX_KICK quirk just like AM33xx. So, enable OMAP_DMA_TX_KICK
quirk for AM437x platform as well. While at that, drop use of
of_machine_is_compatible() and instead pass quirks via device data.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

It is possible that DMA transfer is already complete but, completion
handler is yet to be called, when dmaengine_pause() is called in case of
error condition(like break/rx timeout). This leads to dmaengine_pause()
API to return EINVAL (as descriptor is already NULL) causing
rx_dma_broken flag to be set and effectively disabling RX DMA.
Fix this by calling dmaengine_pause() only when transfer is in progress.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This is needed to work with the client operations which uses const ptrs.

Really, the flags pointer could be const, too, but this would be a tree
wide fix.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty_register_device is just a wrapper for tty_register_device_attr with
NULL passed for drvdata and attr_grp. So similarly make
tty_port_register_device a wrapper of tty_port_register_device_attr so that
additions don't have to be made in both functions.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Let us create tty objects entirely in kernel space. Untested proposal to
show why all the ideas around rewriting half the uart stack are not needed.

With this a kernel created non file backed tty object could be used to handle
data, and set terminal modes. Not all ldiscs can cope with this as N_TTY in
particular has to work back to the fs/tty layer.

The tty_port code is however otherwise clean of file handles as far as I can
tell as is the low level tty port write path used by the ldisc, the
configuration low level interfaces and most of the ldiscs.

Currently you don't have any exposure to see tty hangups because those are
built around the file layer. However a) it's a fixed port so you probably
don't care about that b) if you do we can add a callback and c) you almost
certainly don't want the userspace tear down/rebuild behaviour anyway.

This should however be sufficient if we wanted for example to enumerate all
the bluetooth bound fixed ports via ACPI and make them directly available.
It doesn't deal with the case of a user opening a port that's also kernel
opened and that would need some locking out (so it returned EBUSY if bound
to a kernel device of some kind). That needs resolving along with how you
"up" or "down" your new bluetooth device, or enumerate it while providing
the existing tty API to avoid regressions (and to debug).
Signed-off-by: Alan Cox <alan@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The vendor driver allows setting baud-rates higher than 115200 baud.
There is a check in the vendor driver which prevents using more than
115200 baud during startup, however it does not have such a check in
.set_termios.
Higher baud-rates are often used by the bluetooth modules embedded into
the SDIO wifi chips (Amlogic devices use brcmfmac based wifi chips quite
often, 2000000 baud seems to be a common value for the UART baud-rate in
Amlogic's "libbt").

I have tested this on a Meson GXL device with uart_A (to which the
bluetooth module is connected, where initialization times out with
115200 baud) and uart_AO (which I manually set to 2000000 baud  and then
connected with my USB UART adapter to that).
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For in-kernel tty users, we need to be able to create and destroy
'struct tty' that are not associated with a file. The creation side is
fine, but tty_release() needs to be split into the file handle portion
and the struct tty portion. Introduce a new function, tty_release_struct,
to handle just the destroying of a struct tty.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-By: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Here, If ioremap_nocache will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference.
This error check will avoid NULL pointer dereference.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add DT earlycon for omap_serial driver. This boot console is included
with CONFIG_SERIAL_EARLYCON=y, CONFIG_OF=y, CONFIG_SERIAL_OMAP=y, and
CONFIG_OF_EARLY_FLATTREE=y.

This boot console is enabled with the command line option "earlycon"
(without "=<name>...") when the DT 'stdout-path' property matches a
compatible uart.
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Exactly as in a80c49db ("serial8250: Mark console as CON_ANYTIME"),
to enable printk() during CPU hot-plugging.

Actually most of the serial console drivers do not use per-cpu resources
and can be marked as CON_ANYTIME.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Declare dev_pm_ops structures as const as they are only stored in the pm
field of a device_driver structure. This field is of type const, so
dev_pm_ops structures having similar properties can be declared const
too.

Size details after cross compiling the .o file for blackfin architecture.

File size before:
  text	   data	    bss	    dec	    hex	filename
   3572	    320	     16	   3908	    f44 tty/serial/bfin_sport_uart.o

File size after:
   text	   data	    bss	    dec	    hex	filename
   3664	    228	     16	   3908	    f44 tty/serial/bfin_sport_uart.o
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no need to set PCI bus mastering when device is not doing any DMA. It
includes MSI type of interrupts. Currently only UART on Denverton, which is DMA
capable, might have MSI enabled.

Taking above into account enable bus mastering for Denverton case only.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Enable MSI type of interrupt if PCI BIOS supports it.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Starting from Tangier B0 and continuing on Anniedale the HSU DMA interrupt
line is actually shared with UART. Handling them independently is racy and
quite often comes with the following traceback.

 irq 54: nobody cared (try booting with the "irqpoll" option)
 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc6-edison64-86244934+ #1
 Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
  ffff88003f203eb0 ffffffff8130e718 ffff880032627000 ffff88003262709c
  ffff88003f203ed8 ffffffff810a3960 ffff880032627000 0000000000000000
  ffff880032627000 ffff88003f203f10 ffffffff810a3cc7 ffff880032627000
 Call Trace:
  <IRQ>
  [<ffffffff8130e718>] dump_stack+0x4d/0x65
  [<ffffffff810a3960>] __report_bad_irq+0x30/0xc0
  [<ffffffff810a3cc7>] note_interrupt+0x227/0x270
  [<ffffffff810a1380>] handle_irq_event_percpu+0x40/0x50
  [<ffffffff810a13b7>] handle_irq_event+0x27/0x50
  [<ffffffff810a42d5>] handle_fasteoi_irq+0x85/0x150
  [<ffffffff8101d7fe>] handle_irq+0x6e/0x120
  [<ffffffff8105b8bc>] ? _local_bh_enable+0x1c/0x50
  [<ffffffff8101d0d6>] do_IRQ+0x46/0xd0
  [<ffffffff818cef3f>] common_interrupt+0x7f/0x7f
  <EOI>
  [<ffffffff818cdead>] ? mwait_idle+0x7d/0x140
  [<ffffffff81024c9a>] arch_cpu_idle+0xa/0x10
  [<ffffffff818ce150>] default_idle_call+0x20/0x30
  [<ffffffff810908fd>] cpu_startup_entry+0x16d/0x1d0
  [<ffffffff818c882d>] rest_init+0x6d/0x70
  [<ffffffff81f93e8f>] start_kernel+0x3e2/0x3ef
  [<ffffffff81f9343d>] x86_64_start_reservations+0x38/0x3a
  [<ffffffff81f93529>] x86_64_start_kernel+0xea/0xed
 handlers:
 [<ffffffff81411670>] serial8250_interrupt
 Disabling IRQ #54

Fix this by handling interrupt only in one place.

The issue is discussed here: https://github.com/andy-shev/linux/issues/5

Moreover this also fixes another bug when Rx DMA returns wrong residue and we
can't rely on it.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In the most common use case, the Synopsys DW UART driver does not
set the set_termios callback function.  This prevents UPSTAT_AUTOCTS
from being set when the UART flag CRTSCTS is set.  As a result, the
driver will use software flow control as opposed to hardware flow
control.

To fix the problem, the set_termios callback function is set to the
DW specific function.  The logic to set UPSTAT_AUTOCTS is moved so
that any clock error will not affect setting the hardware flow
control.
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Jason Uy <jason.uy@broadcom.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

SCI instances found in SH SoCs have different spacing between registers
depending on the SoC. The platform data contains a regshift field that
tells the driver by how many bits to shift the register offset to
compute its address. We can compute the regshift value automatically
based on the memory resource size, there's no need to pass the value
through platform data.

Fix the sh7750 SCI and sh7760 SIM port memory resources length to ensure
proper computation of the regshift value.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The field isn't set by any platform but is only used internally in the
driver to hold data parsed from DT. Move it to the sci_port structure.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The sh-sci driver implements manual break debouncing for a few SH
platforms by reading the value of the RX pin port register. This feature
is optional and the driver considers all negative or zero values of the
platform data port_reg field as invalid. As the four platforms that set
the field to a register address all use an address higher than
0x7fffffff, the driver will always consider the value as invalid and
never perform debouncing. The feature is unused, remove it.

Debouncing could be implemented properly in the future using the pinctrl
and GPIO APIs if desired.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Only SH platforms still use platform data for the sh-sci, and none of
them declare DMA channels connected to the SCI. Remove the corresponding
platform data fields and simplify the driver accordingly.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The fifo size, overrun register and mask, sampling rate mask and error
mask all depend on the port type only and don't need to be computed at
runtime. Add them to the sci_port_parameters structure.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver modifies platform data for internal purpose only. Fix that
and make the platform data structure const.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Turn the regmap two-dimensional array to an array of port parameters and
store a pointer to the port parameters in the sci_port structure. This
will allow handling additional port type dependent parameters.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The compiler zeros uninitialized fields, don't zero them manually.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Even though most of its registers are 8-bit wide, the IRDA has two
16-bit registers that make it a 16-bit peripheral and not a 8-bit
peripheral with addresses shifted by one. Fix the registers offset in
the driver and the platform data regshift value.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

According to the datasheets, the sh7760 SIM and sh7723 SCIFA instances
don't implement the REIE bit. Don't set it in platform data.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The bit is only set by platforms that also set the CKE1 but, in which
case its value is ignored by the device. Don't set it, this simplifies
platform data and only leaves the CKE1 bit to be handled.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver considers all negative or zero values of the port_reg field
as invalid. The four platforms that set the field to a register address
all use an address higher than 0x7fffffff, which is thus considered by
the driver as invalid. The feature is thus never used, remove it.

The feature could be implemented properly in the future using the
pinctrl and GPIO APIs if desired.

While at it, don't set the field to SCIx_NOT_SUPPORTED (-1) either,
leaving it unset leads to the same result. This will allow removing the
SCIx_NOT_SUPPORTED macro.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The flag is set by the driver internally, don't set it in platform data.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The SCIF ports on sh7264 and sh7269 don't support the TOIE bit according
to the datasheets.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The scscr platform data field is used by the driver in three locations.
One of them masks out all bits except SCSCR_REIE. The two other are the
set_termios handler and the console write handler.

The set_termios handler calls sci_start_rx() to enable the receiver,
which sets the RIE bit unconditionally. It then calls sci_port_disable()
that effectively disables both the transmitter and the receiver. The
TIE bit will thus get set later when the serial cores reenables the
serial port.

The console write handler runs with interrupts disabled, and saves and
restores the SCSCR register value. The RIE and TIE bits are thus not
needed there.

The bits are thus not necessary in platform data, remove them.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The bits are set by the driver internally, don't set them in platform
data.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The UPF_BOOT_AUTOCONF platform data flag is set by all platforms,
hardcode it.

The UPF_IOREMAP flag is set by a single SH platform and thus needs to be
kept. However, for ARM platforms, we can base the decision on whether an
OF node is present and bypass the platform data flags completely.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The Transmit Enable and Receive Enable bits are set in the scscr field
of all instances of the sh-sci platform data. Set them in the driver
directly to prepare for their removal from platform data.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We want the serial/tty fixes in here as well to build on top of.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull namespace fixes from Eric Biederman:
 "This tree contains 4 fixes.

  The first is a fix for a race that can causes oopses under the right
  circumstances, and that someone just recently encountered.

  Past that are several small trivial correct fixes. A real issue that
  was blocking development of an out of tree driver, but does not appear
  to have caused any actual problems for in-tree code. A potential
  deadlock that was reported by lockdep. And a deadlock people have
  experienced and took the time to track down caused by a cleanup that
  removed the code to drop a reference count"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sysctl: Drop reference added by grab_header in proc_sys_readdir
  pid: fix lockdep deadlock warning due to ucount_lock
  libfs: Modify mount_pseudo_xattr to be clear it is not a userspace mount
  mnt: Protect the mountpoint hashtable with mount_lock

Pull char/misc driver fixes from Greg KH:
 "Here are some small char/misc driver fixes for 4.10-rc4 that resolve
  some reported issues.

  The MEI driver issue resolves a lot of problems that people have been
  having, as does the mem driver fix. The other minor fixes resolve
  other reported issues.

  All of these have been in linux-next for a while"

* tag 'char-misc-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  vme: Fix wrong pointer utilization in ca91cx42_slave_get
  auxdisplay: fix new ht16k33 build errors
  ppdev: don't print a free'd string
  extcon: return error code on failure
  drivers: char: mem: Fix thinkos in kmem address checks
  mei: bus: enable OS version only for SPT and newer

Merge tag 'driver-core-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg KH:
 "Here is a single patch being reverted to remove a feature that was
  added in 4.10-rc1 that isn't quite ready for release.

  It will be redone as a debugfs file instead of a sysfs file in the
  future"

* tag 'driver-core-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "driver core: Add deferred_probe attribute to devices in sysfs"