Commit Graph

83 Commits

Author SHA1 Message Date
Arnd Bergmann
9dd8d5f870 Documentation/watchdog: check return value for magic close
A recent commit added a write to the watchdog test code for doing the "magic
close", but that caused a compile-time warning:

Documentation/watchdog/src/watchdog-test.c: In function ‘main’:
Documentation/watchdog/src/watchdog-test.c:94:5: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]

This changes the code to print a runtime warning if the write fails.

Fixes: 5a2d3de196 ("Documentation/watchdog: add support for magic close to watchdog-test")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Timur Tabi <timur@codeaurora.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-07-25 11:02:17 +02:00
Guenter Roeck
90b826f17a watchdog: Implement status function in watchdog core
Up to now, the watchdog status function called a driver function,
which was supposed to return the watchdog status. All but one
driver using the watchdog core did not implement this function,
and the driver implementing it did not implement it correctly
(the function is supposed to return WDIOF_ flags). At the same time,
at least some of the status information can be provided by the watchdog
core.

Provide the available status bits directly from the watchdog driver core.
Call the driver status function if it exists to get the boot status, but
always provide WDIOF_MAGICCLOSE and WDIOF_KEEPALIVEPING internally.
This patch makes the 'status' sysfs attribute always available.
This attribute is now displayed as hex number with 0x prepended to be
easier to decode.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-07-19 10:09:07 +02:00
Timur Tabi
5a2d3de196 Documentation/watchdog: add support for magic close to watchdog-test
Some drivers have the WDIOF_MAGICCLOSE set, which means that applications
need to write 'V' to the watchdog device before closing, otherwise the
driver won't stop the watchdog timer.

Signed-off-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-07-17 21:02:32 +02:00
Timur Tabi
ee279c2734 Documentation/watchdog: use stdout instead of stderr in watchdog-test
The watchdog-test utility outputs all messages to stderr, even those
that are not error messages.  Output to stdout instead.

Instead of flushing the output after every write, just disabled
the output buffer.

Also display a dot for every ping of the watchdog, so that the user
knows that it's working.

Signed-off-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-07-17 21:02:29 +02:00
Guenter Roeck
f9f535c1b7 watchdog: Improve description of min_hw_heartbeat_ms
The description of min_hw_heartbeat_ms is misleading and needs some
improvements.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-07-17 21:00:14 +02:00
Brian Boylston
0215efc02e watchdog: hpwdt: remove email address from doc
Remove Tom's email address from the documentation

Signed-off-by: Brian Boylston <brian.boylston@hpe.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-07-17 20:54:07 +02:00
William Breathitt Gray
ae67643edc Documentation: Add ebc-c384_wdt watchdog-parameters.txt entry
The WinSystems EBC-C384 watchdog timer driver supports two module
parameters: timeout and nowayout. These parameters should be documented
in the watchdog-parameters.txt file.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-05-14 18:28:29 +02:00
Nigel Croxon
84df082cad watchdog: hpwdt: Adjust documentation to match latest kernel module parameters.
Adjust documentation to match latest kernel module parameters.

Signed-off-by: Nigel Croxon <nigel.croxon@hpe.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-05-14 09:40:36 +02:00
Linus Torvalds
1e75a9f34a Merge git://www.linux-watchdog.org/linux-watchdog
Pull watchdog updates from Wim Van Sebroeck:

 - new drivers for: NI 903x/913x watchdog driver, WinSystems EBC-C384
   watchdog timer and ARM SBSA watchdog driver

 - Support for NCT6102D devices

 - Improvements of the generic watchdog framework (improve restart
   handler, make set_timeout optional, introduce infrastructure
   triggered keepalives, ...

 - improvements on the pnx4008 watchdog driver

 - several smaller fixes and improvements

* git://www.linux-watchdog.org/linux-watchdog: (28 commits)
  watchdog: Ensure that wdd is not dereferenced if NULL
  watchdog: imx2: Convert to use infrastructure triggered keepalives
  watchdog: dw_wdt: Convert to use watchdog infrastructure
  watchdog: Add support for minimum time between heartbeats
  watchdog: Make stop function optional
  watchdog: Introduce WDOG_HW_RUNNING flag
  watchdog: Introduce hardware maximum heartbeat in watchdog core
  watchdog: Make set_timeout function optional
  arm: lpc32xx: remove restart handler
  arm: lpc32xx: phy3250 remove restart hook
  watchdog: pnx4008: restart: support "cmd" from userspace
  watchdog: pnx4008: add support for soft reset
  watchdog: pnx4008: add restart handler
  watchdog: pnx4008: update logging during power-on
  watchdog: tangox_wdt: test clock rate to avoid division by 0
  watchdog: atlas7_wdt: test clock rate to avoid division by 0
  watchdog: s3c2410_wdt: Add max and min timeout values
  Watchdog: introduce ARM SBSA watchdog driver
  Documentation: add sbsa-gwdt driver documentation
  watchdog: Add watchdog timer support for the WinSystems EBC-C384
  ...
2016-03-19 19:35:51 -07:00
Guenter Roeck
15013ad813 watchdog: Add support for minimum time between heartbeats
Some watchdogs require a minimum time between heartbeats.
Examples are the watchdogs in DA9062 and AT91SAM9x.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-16 21:11:19 +01:00
Guenter Roeck
d0684c8a93 watchdog: Make stop function optional
Not all hardware watchdogs can be stopped. The driver for
such watchdogs would typically only set the WATCHDOG_HW_RUNNING
flag in its stop function. Make the stop function optional and set
WATCHDOG_HW_RUNNING in the watchdog core if it is not provided.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-16 21:11:16 +01:00
Guenter Roeck
ee142889e3 watchdog: Introduce WDOG_HW_RUNNING flag
The WDOG_HW_RUNNING flag is expected to be set by watchdog drivers if
the hardware watchdog is running. If the flag is set, the watchdog
subsystem will ping the watchdog even if the watchdog device is closed.

The watchdog driver stop function is now optional and may be omitted
if the watchdog can not be stopped. If stopping the watchdog is not
possible but the driver implements a stop function, it is responsible
to set the WDOG_HW_RUNNING flag in its stop function.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-16 21:11:15 +01:00
Guenter Roeck
664a39236e watchdog: Introduce hardware maximum heartbeat in watchdog core
Introduce an optional hardware maximum heartbeat in the watchdog core.
The hardware maximum heartbeat can be lower than the maximum timeout.

Drivers can set the maximum hardware heartbeat value in the watchdog data
structure. If the configured timeout exceeds the maximum hardware heartbeat,
the watchdog core enables a timer function to assist sending keepalive
requests to the watchdog driver.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-16 21:11:14 +01:00
Guenter Roeck
fb32e9b9de watchdog: Make set_timeout function optional
For some watchdogs, the watchdog driver handles timeout changes without
explicitly setting any registers. In this situation, the watchdog driver
might only set the 'timeout' variable but do nothing else.
This can as well be handled by the infrastructure, so make the set_timeout
callback optional. If WDIOF_SETTIMEOUT is configured but the .set_timeout
callback is not available, update the timeout variable in the
infrastructure code.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-16 21:11:07 +01:00
Fu Wei
2fc94b5f22 Documentation: add sbsa-gwdt driver documentation
The sbsa-gwdt.txt documentation in devicetree/bindings/watchdog is for
introducing SBSA(Server Base System Architecture) Generic Watchdog
device node info into FDT.

Also add sbsa-gwdt introduction in watchdog-parameters.txt

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Fu Wei <fu.wei@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-04 20:23:14 +01:00
Kyle Roeschley
70f3997667 watchdog: ni903x_wdt: Add NI 903x/913x watchdog driver
Add support for the watchdog timer on NI cRIO-903x and cDAQ-913x real-
time controllers.

Signed-off-by: Jeff Westfahl <jeff.westfahl@ni.com>
Signed-off-by: Kyle Roeschley <kyle.roeschley@ni.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-03-01 16:25:39 +01:00
wim.coekaerts@oracle.com
ca0bb07980 Add sun4v_wdt watchdog driver
This driver adds sparc hypervisor watchdog support. The default
timeout is 60 seconds and the range is between 1 and
31536000 seconds. Both watchdog-resolution and
watchdog-max-timeout MD properties settings are supported.

Signed-off-by: Wim Coekaerts <wim.coekaerts@oracle.com>
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-31 11:06:24 -08:00
Guenter Roeck
0254e95353 watchdog: Drop pointer to watchdog device from struct watchdog_device
The lifetime of the watchdog device pointer is different from the lifetime
of its character device. Remove it entirely to avoid race conditions.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-01-11 21:53:59 +01:00
Guenter Roeck
faa584757b watchdog: Add support for creating driver specific sysfs attributes
The Zodiac watchdog driver attaches additional sysfs attributes to the
watchdog device. This has a number of problems: The watchdog device
lifetime differs from the driver lifetime, and the device structure
should therefore not be accessed from drivers. Also, creating sysfs
attributes after driver registration results in a potential race condition
if user space expects the attributes to exist but they don't exist yet.

Add support for creating driver specific sysfs attributes to the watchdog
core to solve the problems.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-01-11 21:53:57 +01:00
Guenter Roeck
b4ffb19098 watchdog: Separate and maintain variables based on variable lifetime
All variables required by the watchdog core to manage a watchdog are
currently stored in struct watchdog_device. The lifetime of those
variables is determined by the watchdog driver. However, the lifetime
of variables used by the watchdog core differs from the lifetime of
struct watchdog_device. To remedy this situation, watchdog drivers
can implement ref and unref callbacks, to be used by the watchdog
core to lock struct watchdog_device in memory.

While this solves the immediate problem, it depends on watchdog drivers
to actually implement the ref/unref callbacks. This is error prone,
often not implemented in the first place, or not implemented correctly.

To solve the problem without requiring driver support, split the variables
in struct watchdog_device into two data structures - one for variables
associated with the watchdog driver, one for variables associated with
the watchdog core. With this approach, the watchdog core can keep track
of its variable lifetime and no longer depends on ref/unref callbacks
in the driver. As a side effect, some of the variables originally in
struct watchdog_driver are now private to the watchdog core and no longer
visible in watchdog drivers.

As a side effect of the changes made, an ioctl will now always fail
with -ENODEV after a watchdog device was unregistered with the character
device still open. Previously, it would only fail with -ENODEV in some
situations. Also, ioctl operations are now atomic from driver perspective.
With this change, it is now guaranteed that the driver will not unregister
a watchdog between a timeout change and the subsequent ping.

The 'ref' and 'unref' callbacks in struct watchdog_driver are no longer
used and marked as deprecated.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-29 20:36:03 +01:00
Damien Riegel
e131319669 watchdog: core: add reboot notifier support
Many watchdog drivers register a reboot notifier in order to stop the
watchdog on system reboot. Thus we can factorize this code in the
watchdog core.

For that purpose, a new notifier block is added in watchdog_device for
internal use only, as well as a new watchdog_stop_on_reboot helper
function.

If this helper is called, watchdog core registers the related notifier
block and will stop the watchdog when SYS_HALT or SYS_DOWN is received.

Since this operation can be critical on some platforms, abort the device
registration if the reboot notifier registration fails.

Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-13 15:55:51 +01:00
Damien Riegel
2165bf524d watchdog: core: add restart handler support
Many watchdog drivers implement the same code to register a restart
handler. This patch provides a generic way to set such a function.

The patch adds a new restart watchdog operation. If a restart priority
greater than 0 is needed, the driver can call
watchdog_set_restart_priority to set it.

Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-12-13 15:27:10 +01:00
Timur Tabi
f15d7114bb Documentation/watchdog: add timeout and ping rate control to watchdog-test.c
The watchdog test program is much more useful if it can configure the
timeout value and ping rate.  This will allow you to test actual timeouts.

Adds the -t parameter to set the timeout value (in seconds), and -p to set
the ping rate (number of seconds between pings).

Signed-off-by: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-09-09 21:33:36 +02:00
Lars Poeschel
b2102eb36e watchdog: omap_wdt: early_enable module parameter
Add a early_enable module parameter to the omap_wdt that starts the
watchdog on module insertion. The default value is 0 which does not
start the watchdog - which also does not change the behavior if the
parameter is not given.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-07-01 16:43:17 +02:00
Jean-Baptiste Theou
ef90174f82 watchdog: watchdog_core: Add watchdog registration deferral mechanism
Currently, watchdog subsystem require the misc subsystem to
register a watchdog. This may not be the case in case of an
early registration of a watchdog, which can be required when
the watchdog cannot be disabled.

This patch introduces a deferral mechanism to remove this requirement.

Signed-off-by: Jean-Baptiste Theou <jtheou@adeneo-embedded.us>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-06-29 11:51:06 +02:00
Lars Poeschel
a47911e99f watchdog: docs: omap_wdt also understands nowayout
The omap_wdt kernel driver also understands the nowayout module
parameter. This updates the watchdog-parameters.txt to reflect this fact.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2015-06-22 15:54:36 +02:00
Peter Foley
df68a01014 Documentation: use subdir-y to avoid unnecessary built-in.o files
Change the Documentation makefiles from obj-m to subdir-y
to avoid generating unnecessary built-in.o files since nothing
in Documentation/ is ever linked in to vmlinux.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-26 11:02:55 +02:00
Sangjung Woo
5be876cf7e Documentation: fix two typos in watchdog-api.txt
This patch changes 'go of' to 'go off' and 'pretimout' to
'pretimeout'.

Signed-off-by: Sangjung Woo <sangjung.woo@samsung.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2014-08-05 22:43:21 +02:00
Marc van der Wal
0bcd0b6a47 watchdog: it87_wdt: Work around non-working CIR interrupts
On some hardware platforms, the it87_wdt watchdog resets the machine
despite the watchdog daemon running and writing to /dev/watchdog.

This is due to Consumer IR buffer underrun interrupts being used as
triggers to reset the timer.  On some buggy hardware implementations
such as the iEi AFL-12A-N270 single-board computer, this method does
not work.

However, resetting the timer by writing its original timeout value in
its configuration register over and over again suppresses the unwanted
reboots.

Add a module option (nocir), 0 by default in order not to break existing
setups.  Setting it to 1 enables the workaround.

Fixes bug #42801 <https://bugzilla.kernel.org/show_bug.cgi?id=42801>.
Tested primarily on Linux 3.5.7, applies cleanly on Linux 3.13.5.

Signed-off-by: Marc van der Wal <x0r+kernel@x0r.fr>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2014-03-31 13:33:55 +02:00
Andrew Chew
c33a15974c watchdog: Add tegra watchdog
Add a driver for the hardware watchdogs in NVIDIA Tegra SoCs (Tegra30 and
later).  This driver will configure one watchdog timer that will reset the
system in the case of a watchdog timeout.

This driver binds to the nvidia,tegra30-timer device node and gets its
register base from there.

Signed-off-by: Andrew Chew <achew@nvidia.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2014-03-31 13:30:29 +02:00
Viresh Kumar
6e63a3a294 watchdog: delete mpcore_wdt driver
Interrupt request doesn't use the right API: The TWD watchdog uses a per-cpu
interrupt (usually interrupt #30), and the GIC configuration should flag it as
such. With this setup, request_irq() should fail, and the right API is
request_percpu_irq(), together with enable_percpu_irq()/disable_percpu_irq().

Nothing ensures the userspace ioctl() will end-up kicking the watchdog on the
right CPU.

There are no users of this driver since a long time and it makes more sense to
get rid of it as nobody is looking to fix it.

In case somebody wakes up after this has been removed and needs it, please
revert this driver and pick these updates (These were never pushed to mainline):

http://comments.gmane.org/gmane.linux.ports.arm.kernel/245998

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-07-11 21:47:58 +02:00
Fabio Porcedda
3048253ed9 watchdog: core: dt: add support for the timeout-sec dt property
Add support for watchdog drivers to initialize/set the timeout field
of the watchdog_device structure. The timeout field is initialised
either with the module timeout parameter value (if valid) or with the
timeout-sec dt property (if valid). If both are invalid the initial
value is unchanged.

Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2013-03-01 12:48:36 +01:00
Randy Dunlap
4b1c2f41c2 watchdog: fix watchdog-test.c build warning
Fix compiler warning by making the function static:

Documentation/watchdog/src/watchdog-test.c:34:6: warning: no previous prototype for 'term'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-08-29 17:12:58 +02:00
Ashish Jangam
664a0d7862 Watchdog: DA9052/53 PMIC watchdog support
This driver adds support for the watchdog functionality provided by
the Dialog Semiconductor DA9052 PMIC chip.

Tested on samsung smdkv6410 and i.mx53 QS boards.

Signed-off-by: Anthony Olech <Anthony.Olech@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30 07:56:12 +02:00
Hans de Goede
e907df3272 watchdog: Add support for dynamically allocated watchdog_device structs
If a driver's watchdog_device struct is part of a dynamically allocated
struct (which it often will be), merely locking the module is not enough,
even with a drivers module locked, the driver can be unbound from the device,
examples:
1) The root user can unbind it through sysfd
2) The i2c bus master driver being unloaded for an i2c watchdog

I will gladly admit that these are corner cases, but we still need to handle
them correctly.

The fix for this consists of 2 parts:
1) Add ref / unref operations, so that the driver can refcount the struct
   holding the watchdog_device struct and delay freeing it until any
   open filehandles referring to it are closed
2) Most driver operations will do IO on the device and the driver should not
   do any IO on the device after it has been unbound. Rather then letting each
   driver deal with this internally, it is better to ensure at the watchdog
   core level that no operations (other then unref) will get called after
   the driver has called watchdog_unregister_device(). This actually is the
   bulk of this patch.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30 07:55:31 +02:00
Hans de Goede
f4e9c82f64 watchdog: Add Locking support
This patch fixes some potential multithreading issues, despite only
allowing one process to open the /dev/watchdog device, we can still get
called multiple times at the same time, since a program could be using thread,
or could share the fd after a fork.

This causes 2 potential problems:
1) watchdog_start / open do an unlocked test_n_set / test_n_clear,
   if these 2 race, the watchdog could be stopped while the active
   bit indicates it is running or visa versa.

2) Most watchdog_dev drivers probably assume that only one
   watchdog-op will get called at a time, this is not necessary
   true atm.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30 07:55:23 +02:00
Alan Cox
d6b469d915 watchdog: create all the proper device files
Create the watchdog class and it's associated devices.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30 07:54:46 +02:00
Alan Cox
45f5fed30a watchdog: Add multiple device support
We keep the old /dev/watchdog interface file for the first watchdog via
miscdev. This is basically a cut and paste of the relevant interface code
from the rtc driver layer tweaked for watchdog.

Revised to fix problems noted by Hans de Goede

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-30 07:54:25 +02:00
Devendra Naga
cad19fa664 Documentation/watchdog: Fix the file descriptor leak when no cmdline arg given
we start a infinite loop when user gives ./watchdog-test, and when user
ctrl + c's the program, we just exit immeadiately with out closing the
filedescriptor of the watchdog device. a signal handler is used to
do the job of closing the filedescriptor and exiting the program.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-23 16:27:48 +02:00
Devendra Naga
3c2a6186c1 Documentation/watchdog: close the fd when cmdline arg given
in the watchdog test code, the ioctl is performed on the watchdog device
and just doing exit(0) so we leak a filedescripor.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-23 16:27:40 +02:00
Devendra Naga
2deca73655 Documentation/watchdog: Fix a small typo
Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-05-23 16:27:00 +02:00
Viresh Kumar
fd7b673c92 watchdog: Add support for WDIOC_GETTIMELEFT IOCTL in watchdog core
This patch adds support for WDIOC_GETTIMELEFT IOCTL in watchdog core. So, there
is another function pointer added to struct watchdog_ops, which can be passed by
drivers to support this IOCTL.

Related documentation is updated too.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27 20:15:37 +02:00
Hans de Goede
b10f7c12e0 watchdog: watchdog_dev: Let the driver update the timeout field on set_timeout success
When a set_timeout operation succeeds this does not necessarily mean that
the exact timeout requested has been achieved, because the watchdog does not
necessarily have a 1 second resolution. So rather then have the core set
the timeout member of the watchdog_device struct to the exact requested
value, instead the driver should set it to the actually achieved timeout value.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27 20:07:43 +02:00
Wolfram Sang
5ba927e8ca watchdog: documentation: remove index-file
The 00-index file in the watchdog directory is, like many others,
outdated (conversion-howto is missing) and doesn't contain worthwhile
additional information. As it seems to be a maintenance burden without
much gain, simply remove it.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27 19:57:26 +02:00
Masanari Iida
e19865219d Documentation: Fix typo in watchdog-kernel-api.txt
Correct spelling "retruns" to "returns" in
Documentations/watchdog/watchdog-kernel-api.txt

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-02-21 11:40:34 +01:00
Wolfram Sang
02861cca4b watchdog: documentation: describe nowayout in coversion-guide
nowayout is also handled by the watchdog core. Describe how this needs
to be addressed in the conversion guide.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-01-06 15:26:14 +01:00
Wim Van Sebroeck
9d36bc8cd8 watchdog: documentation: update index file
Add the convert_drivers_to_kernel_api.txt to the 00-INDEX file.

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-01-06 15:25:47 +01:00
Wim Van Sebroeck
ff0b3cd4a4 watchdog: add nowayout helpers to Watchdog Timer Driver Kernel API
Add two nowayout helpers for the Watchdog Timer Driver Kernel API.
And apply this to the already converted drivers.
Note: s3c2410_wdt lost the nowayout feature during the conversion.

Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-01-06 15:22:04 +01:00
Wolfram Sang
74cd4c6739 Documentation: watchdog: add guide how to convert drivers to new framework
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2011-11-05 21:25:16 +01:00
Wim Van Sebroeck
3f43f68e29 watchdog: WatchDog Timer Driver Core - Add minimum and max timeout
Add min_timeout (minimum timeout) and max_timeout
values so that the framework can check if the new
timeout value is between the minimum and maximum
timeout values. If both values are 0, then the
framework will leave the check for the watchdog
device driver itself.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-07-28 08:01:18 +00:00