Commit Graph

574662 Commits

Author SHA1 Message Date
Paul Gortmaker
e3c5fc4d47 drivers/tty: make hvc/hvc_vio.c explicitly non-modular
The Kconfig currently controlling compilation of this code is:

drivers/tty/hvc/Kconfig:config HVC_CONSOLE
drivers/tty/hvc/Kconfig:        bool "pSeries Hypervisor Virtual Console support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We explicitly disallow a driver unbind, since that doesn't have a
sensible use case anyway, and it allows us to drop the ".remove"
code for non-modular drivers.

We don't replace module.h with init.h since the file already has that.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Blanchard <anton@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:26:43 -08:00
Anton Wuerfel
b3bd666807 tty: serial: 8250: Add generic port init macro
This patch removes redundant 8250 port initialization macros and
replaces them by a single generic base-macro, which is specialized
as needed.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
b3d67936bf tty: serial: 8250: Fix indentation warnings
Checkpatch complains about incorrect indentation of switch/case statements.
This patch fixes the corresponding warnings. Additionally some indentation
is changed to match the correct format specified in the Linux Kernel
Coding Style.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
829b000024 tty: serial: 8250: Merge duplicate conditions
This patch refactors a switch case statement by merging an if condition
in the default case into an identical condition right after the switch
statement.
This comes with a slight change in behaviour: If pci_netmos_9900_numports
returns 0, an additional warning is printed.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
9faef1cb33 tty: serial: 8250: Correct conversion specifiers
This patch fixes compiler warnings about wrong conversion specifiers used
in a debug output in 8250_pnp.c. The precise warning is:

drivers/tty/serial/8250/8250_pnp.c: In function ‘serial_pnp_probe’:
include/linux/dynamic_debug.h:64:16: warning: format ‘%x’ expects argument
of [...]

drivers/tty/serial/8250/8250_pnp.c:467:2: note: in expansion of macro
‘dev_dbg’
  dev_dbg(&dev->dev,
  ^
include/linux/dynamic_debug.h:64:16: warning: format ‘%lx’ expects argument
of [...]

drivers/tty/serial/8250/8250_pnp.c:467:2: note: in expansion of macro
‘dev_dbg’
  dev_dbg(&dev->dev,
  ^

Those warnings never got triggered, because the command was nested
in an #ifdef, which is removed by a patch of this series.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Phillip Raffeck
952773b52b tty: serial: 8250: Remove SERIAL_DEBUG_PNP macro
This patch removes the macro SERIAL_DEBUG_PNP, which is used to enable
debugging at compile time.
As SERIAL_DEBUG_PNP is an orphan, the corresponding #ifdef is removed.
To keep the ability to enable debugging at compile time,
the call to printk(KERN_DEBUG ...) is replaced by a corresponding
call to dev_dbg(), which is configurable via CONFIG_DYNAMIC_DEBUG.

Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Phillip Raffeck
9f59fbf0f2 tty: serial: 8250: Suitably replace printk
This patch replaces printk by the corresponding variant of dev_* in order
to fix checkpatch warnings. If no suitable device pointer is present, the
corresponding pr_* variant is used.

Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
90ad7c442f tty: serial: 8250: Fix multi-line strings
Merged user-visible multi-line strings into a single line according to the
Linux Kernel Coding Style, which allows user-visible strings to exceed the
maximum line length of 80 characters. The main reason for this is to
facilitate grepping for these strings.
However, some strings were ignored in this patch, because the use of
format specifiers breaks the ability to grep anyway.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
149a44cc98 tty: serial: 8250: Add parentheses to macro
This patch fixes a checkpatch warning caused by missing parentheses
in the definition of a macro.
Furthermore redundant parentheses are removed in an assignment.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
207c28b1c6 tty: serial: 8250: Fix line continuation warning
Fixed checkpatch warning about an unnecessary line continuation in a
multi-line variable assignment.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
b34f9fafea tty: serial: 8250: Move EXPORT_SYMBOL to function
This patch moves EXPORT_SYMBOL macros directly after the definition of
the corresponding symbol to remove checkpatch warnings.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
c2f5fde143 tty: serial: 8250: Remove else after return
This patch fixes checkpatch warnings about unnecessary else blocks after
return statements.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
740dc2defc tty: serial: 8250: Fix multiline comment style
Checkpatch outputs some warnings about incorrect comment style,
which is fixed by this patch.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
f7941f508d tty: serial: 8250: Fix braces after struct
This patch fixes a checkpatch warning by moving an opening curly brace
to its correct position.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
6d7c157fc7 tty: serial: 8250: Replace spaces with tabs
Indentation is changed to match the correct format of using tabs instead
of spaces wherever possible.

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Anton Wuerfel
1a33e342cf tty: serial: 8250: Fix whitespace errors
This patch fixes whitespace errors reported by checkpatch to increase
readability. Main focus is on missing spaces after commas in
function headers and macros (like foo,bar edited to foo, bar).

Signed-off-by: Anton Würfel <anton.wuerfel@fau.de>
Signed-off-by: Phillip Raffeck <phillip.raffeck@fau.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-kernel@i4.cs.fau.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:15:53 -08:00
Maciej W. Rozycki
fff21fac75 serial: zs: Fix a transmit lockup in console output
Transmit interrupts are disabled and the transmit buffer drained in the
course of console output so that polled transmission is possible.  That
however causes a lost transmit interrupt as the TxIP bit in RR3 is only
set on a transmit buffer full-to-empty transition and then iff transmit
interrupts are enabled at the same time.  Consequently if console output
disturbs a regular transmission in progress, the TxIP bit is never set
again and the transmission locks up waiting for a transmit interrupt.

Fix the problem by restarting transmission manually rather than waiting
for a transmit interrupt that will never happen.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:13:30 -08:00
Martin Sperl
bdc5f30095 serial: bcm2835: add driver for bcm2835-aux-uart
The bcm2835 SOC contains an auxiliary uart, which is very close
to the ns16550 with some differences.

The big difference is that the uart HW is not using an internal divider
of 16 but 8, which results in an effictive baud-rate being twice
the requested baud-rate.

This driver handles this device correctly and handles the difference in
the HW divider by scaling up the clock by a factor of 2.

The approach to write a separate (wrapper) driver instead of using a
multiplying clock and "ns16550" as compatibility in the device-tree
has been recommended by Stephen Warren.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:13:30 -08:00
Martin Sperl
45d7e9a51c dt/bindings: serial: bcm2835: add binding documentation for bcm2835-aux-uart
Add binding documentation for the bcm2835-aux-uart driver.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:13:30 -08:00
Wang Dongsheng
434ba16e86 serial: 8250: of: Enable suspend/resume for 8250_of driver
Suspend/resume functions should work for 8250_of driver.

Signed-off-by: Wang Dongsheng <dongsheng.wang@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:13:30 -08:00
Jean Delvare
1349ba02bf ARM: OMAP: serial: Rename DRIVER_NAME
DRIVER_NAME is too generic to be used in a driver-specific platform
data file. Use a name specific to the driver instead, to avoid
collisions.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:13:30 -08:00
Jeremy McNicoll
7dde55787b tty: Add support for PCIe WCH382 2S multi-IO card
WCH382 2S board is a PCIe card with 2 DB9 COM ports detected as
Serial controller: Device 1c00:3253 (rev 10) (prog-if 05 [16850])

Signed-off-by: Jeremy McNicoll <jmcnicol@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:08:00 -08:00
Arnd Bergmann
b4a512b8bf serial/omap: mark wait_for_xmitr as __maybe_unused
The wait_for_xmitr() function is only used if CONFIG_CONSOLE_POLL
or CONFIG_SERIAL_OMAP_CONSOLE are set, but when both are disabled,
the compiler warns about it being unused:

drivers/tty/serial/omap-serial.c:1168:13: warning: 'wait_for_xmitr' defined but not used [-Wunused-func

We could add more #ifdefs to work around it, but adding __maybe_unused
seems nicer.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 2172076d23 ("serial/omap-serial: Deinline wait_for_xmitr, save 165 bytes")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:04:51 -08:00
Peter Hurley
308bbc9ab8 serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485)
The omap-serial driver emulates RS485 delays using software timers,
but neglects to clamp the input values from the unprivileged
ioctl(TIOCSRS485). Because the software implementation busy-waits,
malicious userspace could stall the cpu for ~49 days.

Clamp the input values to < 100ms.

Fixes: 4a0ac0f55b ("OMAP: add RS485 support")
Cc: <stable@vger.kernel.org>  # 3.12+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:04:51 -08:00
Arnd Bergmann
d56edd7ed0 8250: uniphier: allow modular build with 8250 console
The recently added uniphier 8250 port driver supports early console
probing, and it supports being built as a module, but the combination
of the two fails to link:

ERROR: "early_serial8250_setup" [drivers/tty/serial/8250/8250_uniphier.ko] undefined!

Given that earlycon support in a loadable module makes no sense,
making that code conditional on 'MODULE' is a correct solution.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b8d20e06ea ("serial: 8250_uniphier: add earlycon support")
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 23:04:51 -08:00
Rich Felker
9e370d2c9f serial-uartlite: fix missing locking in isr
The uartlite driver suffers from missing/duplicate/corrupted character
data when the interrupt handler runs concurrently with access to the
device from another cpu. Take the port spinlock to exclude concurrent
access.

Signed-off-by: Rich Felker <dalias@libc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:56:43 -08:00
Rich Felker
7cdcc29e49 serial-uartlite: add earlycon support
Microblaze currently uses the old earlyprintk system, rather than the
unified earlycon support, to show boot messages on uartlite. Add
earlycon support so that other archs using uartlite can benefit from
it. The new code in uartlite.c is copied almost verbatim from
arch/microblaze/kernel/early_printk.c.

Signed-off-by: Rich Felker <dalias@libc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:56:43 -08:00
Paul Gortmaker
cafe1ac640 drivers/tty: make serial 8250_ingenic.c explicitly non-modular
The Kconfig currently controlling compilation of this code is:

drivers/tty/serial/8250/Kconfig:config SERIAL_8250_INGENIC
drivers/tty/serial/8250/Kconfig:        bool "Support for Ingenic SoC serial ports"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

We explicitly disallow a driver unbind, since that doesn't have a
sensible use case anyway, and it allows us to drop the ".remove"
code for non-modular drivers.

Since module_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:56:43 -08:00
Simon Horman
020641768a serial: sh-sci: Add device tree support for r8a7792
Simply document new compat strings.
There appears to be no need for a driver updates.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:54:55 -08:00
Jeffy Chen
ba47f97a18 serial: core: remove baud_rates when serial console setup
Currently, when tring to set up a serial console with a higher
baud rate, it would fallback to 921600.

Tested-by: Jianqun Xu <jay.xu@rock-chips.com>
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:54:55 -08:00
Geert Uytterhoeven
92a0574867 serial: sh-sci: Add support for SCIFA/SCIFB variable sampling rates
Add support for sparse variable sampling rates on SCIFA and SCIFB.
According to the datasheet, sampling rate 1/5 needs a small quirk to
avoid corrupting the first byte received.

This increases the range and accuracy of supported baud rates.
E.g. on r8a7791/koelsch:
  - Supports now 134, 150, and standard 500000-4000000 bps,
  - Perfect match for 134, 150, 500000, 1000000, 2000000, and 4000000
    bps,
  - Accuracy has increased for most standard bps values.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:54:55 -08:00
Geert Uytterhoeven
69eee8e9c8 serial: sh-sci: Use a bitmask to indicate supported sampling rates
Replace the single sampling rate and special handling for HSCIF's
variable sampling rates by a bitmask and a custom iterator.
This prepares for the advent of SCIFA/SCIFB's sparse variable sampling
rates.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:54:55 -08:00
Geert Uytterhoeven
7b5c0c08f5 serial: sh-sci: Use premultiplier to handle half sampling rate
On SCIx variants different from HSCIF, the bit rate is equal to the
sampling clock rate divided by half the sampling rate. Currently this is
handled by dividing the sampling rate by two, which was OK as it was
always even.

Replace halving the sampling rate by premultiplying the base clock
frequency by 2, to accommodate odd sampling rates on SCIFA/SCIFB later.

Replace the shift value in the BRG divider calculation by a
premultiplication of the base clock frequency too, for consistency.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:54:55 -08:00
Geert Uytterhoeven
3a964abe1e serial: sh-sci: Preserve SCIFA/SCIFB bit rate config for serial console
SCIFA and SCIFB have additional bit rate config bits in the Serial Mode
Register.  Don't touch them when using the port as a serial console, as
we rely on the boot loader to have configured the serial port config.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:54:55 -08:00
Geert Uytterhoeven
95ee05c7ad serial: sh-sci: Add more Serial Mode Register documentation
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:54:55 -08:00
Martin Fuzzey
29add68d16 serial: imx: Fix suspend / resume.
When a non console i.MX UART is enabled in the device tree,
system suspend fails due to an unprepared clock:

[  638.794563] PM: Syncing filesystems ... done.
[  638.878902] Freezing user space processes ... (elapsed 0.002 seconds) done.
[  638.888454] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[  638.996697] PM: suspend of devices complete after 97.200 msecs
[  639.002611] PM: suspend devices took 0.100 seconds
[  639.013020] PM: late suspend of devices complete after 2.288 msecs
[  639.021486] ------------[ cut here ]------------
[  639.026147] WARNING: CPU: 0 PID: 488 at drivers/clk/clk.c:732 clk_core_enable+0xc0/0x12c()
[  639.034413] Modules linked in:
[  639.037490] CPU: 0 PID: 488 Comm: system_server Tainted: G        W       4.4.0-rc5-pknbsp-svn2214-atag-v4.4-rc5-121-gebfd9cb #1304
[  639.049312] Hardware name: Freescale i.MX53 (Device Tree Support)
[  639.055444] [<c0016d54>] (unwind_backtrace) from [<c00140f8>] (show_stack+0x20/0x24)
[  639.063199] [<c00140f8>] (show_stack) from [<c02c99a0>] (dump_stack+0x20/0x28)
[  639.070442] [<c02c99a0>] (dump_stack) from [<c0024ca8>] (warn_slowpath_common+0x88/0xc0)
[  639.078541] [<c0024ca8>] (warn_slowpath_common) from [<c0024d0c>] (warn_slowpath_null+0x2c/0x34)
[  639.087332] [<c0024d0c>] (warn_slowpath_null) from [<c05171e8>] (clk_core_enable+0xc0/0x12c)
[  639.095777] [<c05171e8>] (clk_core_enable) from [<c05172f8>] (clk_enable+0x2c/0x40)
[  639.103441] [<c05172f8>] (clk_enable) from [<c0349880>] (imx_serial_port_suspend_noirq+0x20/0xe0)
[  639.112336] [<c0349880>] (imx_serial_port_suspend_noirq) from [<c03a26a0>] (dpm_run_callback+0x68/0x16c)
[  639.121825] [<c03a26a0>] (dpm_run_callback) from [<c03a2898>] (__device_suspend_noirq+0xf4/0x22c)
[  639.130705] [<c03a2898>] (__device_suspend_noirq) from [<c03a4b0c>] (dpm_suspend_noirq+0x148/0x30c)
[  639.139764] [<c03a4b0c>] (dpm_suspend_noirq) from [<c00511d4>] (suspend_devices_and_enter+0x2e8/0x6a4)
[  639.149078] [<c00511d4>] (suspend_devices_and_enter) from [<c00518a0>] (pm_suspend+0x310/0x4b8)
[  639.157782] [<c00518a0>] (pm_suspend) from [<c00500ec>] (state_store+0x7c/0xcc)
[  639.165099] [<c00500ec>] (state_store) from [<c02cb6dc>] (kobj_attr_store+0x1c/0x28)
[  639.172858] [<c02cb6dc>] (kobj_attr_store) from [<c01633d4>] (sysfs_kf_write+0x54/0x58)
[  639.180871] [<c01633d4>] (sysfs_kf_write) from [<c01629b4>] (kernfs_fop_write+0x100/0x1c8)
[  639.189152] [<c01629b4>] (kernfs_fop_write) from [<c00fb8b8>] (__vfs_write+0x3c/0xe8)
[  639.196991] [<c00fb8b8>] (__vfs_write) from [<c00fc810>] (vfs_write+0xa4/0x160)
[  639.204307] [<c00fc810>] (vfs_write) from [<c00fcac4>] (SyS_write+0x4c/0x98)
[  639.211363] [<c00fcac4>] (SyS_write) from [<c0010760>] (ret_fast_syscall+0x0/0x3c)

This does not happen for the common case of a single UART used as a console
(since imx_console_setup() already does a prepare)

Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:53:43 -08:00
Soren Brinkmann
07986580d0 tty: xuartps: Consolidate TX handling
start_tx and the ISR used largely identical code to transmit data.
Consolidate that in one place.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
a8df6a5160 tty: xuartps: Remove '_OFFSET' suffix from #defines
Remove the _OFFSET suffix from all register defines which makes code a
little easier to read and avoids a few line breaks.

Suggested-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
74ea66d4ca tty: xuartps: Improve sysrq handling
Handling magic sysrq included dropping a lock to avoid a deadlock that
happened when cdns_uart_console_write tried to acquire a lock in the
from the sysrq code path. By making the acquisition of the lock in
cdns_uart_console_write depending on port->sysrq, cdns_uart_handle_rx can be
simplified to simply call uart_handle_sysrq.

Suggested-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
354fb1a7d7 tty: xuartps: Cleanup: Reformat if-else
Convert an if-else into the more common early return on error, reducing
the indent level of the happy path.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
373e882f9e tty: xuartps: Refactor IRQ handling
The system could deadlock handling RX IRQs when RX-related IRQ
conditions became true while the receiver was disabled. To avoid this,
enable/disable the RX/TX IRQs together with the receiver/transmitter.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
55861d11c5 tty: xuartps: Move request_irq to after setting up the HW
Request_irq() should be _after_ h/w programming, otherwise an
interrupt could be triggered and in-progress before the h/w has been
setup.

Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:23 -08:00
Soren Brinkmann
5ede4a5cde tty: xuartps: Move RX path into helper function
Move RX-related IRQ handling into a helper function.
Fixes a problem where every char received after a parity or frame error
in the current isr will also be tagged as a parity or frame error.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
a19eda0f49 tty: xuartps: Acquire port lock for shutdown
Shutting down the UART port can happen while console operations are in
progress. Holding the port lock serializes these operations and avoids
the UART HW to be disabled in the middle of console prints.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
4c0b92ed9e tty: xuartps: Keep lock for whole ISR
The RX path in the interrupt handler released a lock unnecessarily.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
6e14f7c1f2 tty: xuartps: Improve startup function
The startup function is supposed to initialize the UART for receiving.
Hence, don't enable the TX part. Also, protect HW accesses with the port
lock.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
aea8f3ddcf tty: xuartps: Clear interrupt status register in shutdown
When shutting down the UART, clear the interrupt status register. Bits
in the ISR are cleared by writing them as '1'.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
ea8dd8e585 tty: xuartps: Don't consider circular buffer when enabling transmitter
Restarting the transmitter even if the circ buffer is empty may be
necessary to push out remaining data when the port is restarted after
being stopped.

Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
f0f54a806b tty: xuartps: Use spinlock to serialize HW access
Instead of disabling the IRQ, use the spin lock to serialize accesses to
the HW. This protects the driver from interference of non-IRQ callbacks
with each other and makes the driver more consistent in its
serialization method.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00
Soren Brinkmann
e3538c37ee tty: xuartps: Beautify read-modify writes
Non-functional, formatting changes to ease reading the code.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:52:09 -08:00