Commit Graph

106 Commits

Author SHA1 Message Date
Mauro Carvalho Chehab cc2a2d19f8 docs: watchdog: convert docs to ReST and rename to *.rst
Convert those documents and prepare them to be part of the kernel
API book, as most of the stuff there are related to the
Kernel interfaces.

Still, in the future, it would make sense to split the docs,
as some of the stuff is clearly focused on sysadmin tasks.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:32:05 -06:00
Mauro Carvalho Chehab d67297ad34 docs: kdump: convert docs to ReST and rename to *.rst
Convert kdump documentation to ReST and add it to the
user faced manual, as the documents are mainly focused on
sysadmins that would be enabling kdump.

Note: the vmcoreinfo.rst has one very long title on one of its
sub-sections:

	PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab|PG_hwpoision|PG_head_mask|PAGE_BUDDY_MAPCOUNT_VALUE(~PG_buddy)|PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline)

I opted to break this one, into two entries with the same content,
in order to make it easier to display after being parsed in html and PDF.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:21:24 -06:00
Michael Shych 9d489ad121 Documentation/watchdog: Add documentation mlx-wdt driver
Add documentation with details of Mellanox watchdog driver.

Signed-off-by: Michael Shych <michaelsh@mellanox.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@linux-watchdog.org>
2019-03-02 15:28:20 +01:00
Wolfram Sang 2b6d86a73e watchdog: docs: kernel-api: don't reference removed functions
Those functions are not only deprecated, but gone for good.

Fixes: 62cd1c40ce ("watchdog: kill unref/ref ops")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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@linux-watchdog.org>
2018-12-24 13:15:06 +01:00
Wolfram Sang e536f7304b watchdog: add documentation for PM usage
Add the first rule we recently agreed on.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.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@linux-watchdog.org>
2018-12-24 13:15:06 +01:00
Marek Behún cd69606ad0 documentation: watchdog: add documentation for armada-37xx-wdt
Add documentation for the kernel module parameters accepted by
armada-37xx-wdt.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2018-10-13 15:19:40 +02:00
Jerry Hoemann 18bd1963ae watchdog: hpwdt: Update Driver Documentation.
Remove references to deprecated features like NMI sourcing
and obsoleted module parameters.

Add details concerning new module parameter pretimeout and tips
to programming it.

Signed-off-by: Jerry Hoemann <jerry.hoemann@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@linux-watchdog.org>
2018-10-02 13:32:23 +02:00
Arnd Bergmann 011bf62430 watchdog: remove bfin_wdt driver
The blackfin architecture is getting removed, so this driver has
become obsolete.

Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Aaron Wu <aaron.wu@analog.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2018-03-26 15:57:04 +02:00
Corentin Labbe 592a547adf documentation: watchdog: remove documentation of w83697hf_wdt/w83697ug_wdt
Since w83697hf_wdt/w83697ug_wdt watchdogs drivers were removed
in commit 7285fae934 ("watchdog: Remove drivers for W83697HF and W83697UG")
There are no need to keep their documentation

Signed-off-by: Corentin Labbe <clabbe@baylibre.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>
2018-02-03 11:09:54 +01:00
Corentin Labbe 7171b137f8 documentation: watchdog: remove documentation for ixp2000
The ixp2000 watchdog driver was removed in commit 065e823830 ("watchdog: remove ixp2000 driver")

No need to keep its documentation, so remove it.

Signed-off-by: Corentin Labbe <clabbe@baylibre.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>
2018-02-03 11:09:53 +01:00
Corentin Labbe 71ea98ffef documentation: watchdog: remove documentation of at32ap700x_wdt
Since at32ap700x_wdt is gone, no need to keep its documentation

Signed-off-by: Corentin Labbe <clabbe@baylibre.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>
2018-02-03 11:09:53 +01:00
Tom Saeger 718d50ec78 Documentation: fix selftests related file refs
Make refs to selftests files valid including:
  - watchdog-test.c
  - dnotify_test.c

Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-10-19 12:58:21 -06:00
Wim Van Sebroeck fc61e83a29 watchdog: Revert "iTCO_wdt: all versions count down twice"
This reverts commit 1fccb73011.
Reported as Bug 196509 - iTCO_wdt regression reboot before timeout expire

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2017-09-09 17:41:24 +02:00
Keiji Hayashibara e7bf02895f watchdog: uniphier: add UniPhier watchdog driver
Add a watchdog driver for Socionext UniPhier series SoC.
Note that the timeout value for this device must be a power
of 2 because of the specification.

Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.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>
2017-07-03 13:58:55 +02:00
Paolo Bonzini 1fccb73011 iTCO_wdt: all versions count down twice
The ICH9 is listed as having TCO v2, and indeed the behavior in the
datasheet corresponds to v2 (for example the NO_REBOOT flag is
accessible via the 16KiB-aligned Root Complex Base Address).

However, the TCO counts twice just like in v1; the documentation
of the SECOND_TO_STS bit says: "ICH9 sets this bit to 1 to indicate
that the TIMEOUT bit had been (or is currently) set and a second
timeout occurred before the TCO_RLD register was written. If this
bit is set and the NO_REBOOT config bit is 0, then the ICH9 will
reboot the system after the second timeout.  The same can be found
in the BayTrail (Atom E3800) datasheet, and even HOWTOs around
the Internet say that it will reboot after _twice_ the specified
heartbeat.

I did not find the Apollo Lake datasheet, but because v4/v5 has
a SECOND_TO_STS bit just like the previous version I'm enabling
this for Apollo Lake as well.

Cc: linux-watchdog@vger.kernel.org
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.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>
2017-05-19 10:42:11 +02:00
Guenter Roeck bb292ac1c6 watchdog: Introduce watchdog_stop_on_unregister helper
Many watchdog drivers explicitly stop the watchdog when unregistering it.
While it is unclear if this is actually needed (the whatdog should not be
running at that time if it can be stopped), introduce a helper to
explicitly stop the watchdog in the watchdog core when unregistering it.
This helps reducing driver code size while retaining functionality.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24 14:00:23 -08:00
Hui Chun Ong 98078ca34a watchdog: nic7018_wdt: Add NIC7018 watchdog driver
Add support for the watchdog timer on PXI Embedded Controller.

Signed-off-by: Hui Chun Ong <hui.chun.ong@ni.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24 14:00:23 -08:00
Mauro Carvalho Chehab 8c27ceff36 docs: fix locations of several documents that got moved
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24 08:12:35 -02:00
Linus Torvalds 5d89d9f502 linux-kselftest-4.9-rc1-update
This update consists of:
 
 - Fixes and improvements to existing tests
 - Moving code from Documentation to selftests, samples, and tools.
 
   Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and networking
   tests from Documentation to selftests.
 
   Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay, and
   blackfin examples from Documentation to samples.
 
   Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
   Documentation to tools.
 
   Deletes BUILD_DOCSRC and its dependencies.
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Merge tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest updates from Shuah Khan:
 "This update consists of:

   - Fixes and improvements to existing tests

   - Moving code from Documentation to selftests, samples, and tools:

     * Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and
       networking tests from Documentation to selftests.

     * Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay,
       and blackfin examples from Documentation to samples.

     * Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
       Documentation to tools.

     * Deletes BUILD_DOCSRC and its dependencies"

* tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (21 commits)
  selftests/futex: Check ANSI terminal color support
  Doc: update 00-INDEX files to reflect the runnable code move
  samples: move blackfin gptimers-example from Documentation
  tools: move pcmcia crc32hash tool from Documentation
  tools: move laptops dslm tool from Documentation
  tools: move accounting tool from Documentation
  samples: move auxdisplay example code from Documentation
  samples: move watchdog example code from Documentation
  samples: move timers example code from Documentation
  samples: move misc-devices/mei example code from Documentation
  samples: move mic/mpssd example code from Documentation
  selftests: Move networking/timestamping from Documentation
  selftests: move watchdog tests from Documentation/watchdog
  selftests: move ia64 tests from Documentation/ia64
  selftests: move vDSO tests from Documentation/vDSO
  selftests: move ptp tests from Documentation/ptp
  selftests: move prctl tests from Documentation/prctl
  selftests: move dnotify_test from Documentation/filesystems
  selftests/timers: Add missing error code assignment before test
  selftests/zram: replace ZRAM_LZ4_COMPRESS
  ...
2016-10-14 15:17:12 -07:00
Vladimir Zapolskiy ff84136cb6 watchdog: add watchdog pretimeout governor framework
The change adds a simple watchdog pretimeout framework infrastructure,
its purpose is to allow users to select a desired handling of watchdog
pretimeout events, which may be generated by some watchdog devices.

A user selects a default watchdog pretimeout governor during
compilation stage.

Watchdogs with WDIOF_PRETIMEOUT capability now have one more device
attribute in sysfs, pretimeout_governor attribute is intended to display
the selected watchdog pretimeout governor.

The framework has no impact at runtime on watchdog devices with no
WDIOF_PRETIMEOUT capability set.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2016-10-08 10:27:10 +02:00
Wolfram Sang df044e0220 watchdog: add pretimeout support to the core
Since the watchdog framework centrializes the IOCTL interfaces of device
drivers now, SETPRETIMEOUT and GETPRETIMEOUT need to be added in the
common code.

Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[vzapolskiy: added conditional pretimeout sysfs attribute visibility]
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.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>
2016-09-24 09:27:15 +02:00
Shuah Khan 071bf69a02 samples: move watchdog example code from Documentation
Move watchdog examples to samples and remove it from Documentation
Makefile. Create a new Makefile to build watchdog. It can be built
from top level directory or from watchdog directory:

Run make -C samples/watchdog or cd samples/watchdog; make

Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2016-09-23 11:52:14 -06:00
Shuah Khan 02a35aad8a selftests: move watchdog tests from Documentation/watchdog
Remove watchdog-test from Makefile to move the test to selftests.

Add Makefile and .gitignore for watchdog-test. watchdog-test will
not be run as part of selftests suite and will not be included in
install targets.  It can be built separately for now.

Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2016-09-20 09:58:34 -06:00
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