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* watchdog: Add support for dynamically allocated watchdog_device structsHans de Goede2012-05-301-1/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* watchdog: Add Locking supportHans de Goede2012-05-301-0/+2
| | | | | | | | | | | | | | | | | | | 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>
* watchdog: create all the proper device filesAlan Cox2012-05-301-0/+5
| | | | | | | | 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>
* watchdog: Add multiple device supportAlan Cox2012-05-301-1/+9
| | | | | | | | | | | | | 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>
* Documentation/watchdog: Fix a small typoDevendra Naga2012-05-231-1/+1
| | | | | Signed-off-by: Devendra Naga <devendra.aaru@gmail.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
* watchdog: Add support for WDIOC_GETTIMELEFT IOCTL in watchdog coreViresh Kumar2012-03-271-1/+3
| | | | | | | | | | | | 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>
* watchdog: watchdog_dev: Let the driver update the timeout field on ↵Hans de Goede2012-03-271-3/+4
| | | | | | | | | | | | | 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>
* Documentation: Fix typo in watchdog-kernel-api.txtMasanari Iida2012-02-211-1/+1
| | | | | | | | 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>
* watchdog: add nowayout helpers to Watchdog Timer Driver Kernel APIWim Van Sebroeck2012-01-061-1/+9
| | | | | | | | | | 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>
* watchdog: WatchDog Timer Driver Core - Add minimum and max timeoutWim Van Sebroeck2011-07-281-0/+4
| | | | | | | | | | | | | | | 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>
* watchdog: WatchDog Timer Driver Core - Add ioctl callWim Van Sebroeck2011-07-281-0/+5
| | | | | | | | | | | | | | | | | | Add support for extra ioctl calls by adding a ioctl watchdog operation. This operation will be called before we do our own handling of ioctl commands. This way we can override the internal ioctl command handling and we can also add extra ioctl commands. The ioctl watchdog operation should return the appropriate error codes or -ENOIOCTLCMD if the ioctl command should be handled through the internal ioctl handling of the framework. 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>
* watchdog: WatchDog Timer Driver Core - Add nowayout featureWim Van Sebroeck2011-07-281-5/+8
| | | | | | | | | | | | | Add support for the nowayout feature to the WatchDog Timer Driver Core framework. This feature prevents the watchdog timer from being stopped. 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>
* watchdog: WatchDog Timer Driver Core - Add Magic Close featureWim Van Sebroeck2011-07-281-0/+7
| | | | | | | | | | | Add support for the Magic Close feature to the WatchDog Timer Driver Core framework. 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>
* watchdog: WatchDog Timer Driver Core - Add WDIOC_SETTIMEOUT and ↵Wim Van Sebroeck2011-07-281-0/+10
| | | | | | | | | | | | | WDIOC_GETTIMEOUT ioctl This part add's the WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl functionality to the WatchDog Timer Driver Core framework. 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>
* watchdog: WatchDog Timer Driver Core - Add WDIOC_SETOPTIONS ioctlWim Van Sebroeck2011-07-281-2/+7
| | | | | | | | | | | This part add's the WDIOC_SETOPTIONS ioctl functionality to the WatchDog Timer Driver Core framework. 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>
* watchdog: WatchDog Timer Driver Core - Add WDIOC_KEEPALIVE ioctlWim Van Sebroeck2011-07-281-0/+3
| | | | | | | | | | | | | This part add's the WDIOC_KEEPALIVE ioctl functionality to the WatchDog Timer Driver Core framework. Please note that the WDIOF_KEEPALIVEPING bit has to be set in the watchdog_info options field. 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>
* watchdog: WatchDog Timer Driver Core - Add basic ioctl functionalityWim Van Sebroeck2011-07-281-0/+6
| | | | | | | | | | | | | | | This part add's the basic ioctl functionality to the WatchDog Timer Driver Core framework. The supported ioctl call's are: WDIOC_GETSUPPORT WDIOC_GETSTATUS WDIOC_GETBOOTSTATUS 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>
* watchdog: WatchDog Timer Driver Core - Add basic frameworkWim Van Sebroeck2011-07-281-0/+119
The WatchDog Timer Driver Core is a framework that contains the common code for all watchdog-driver's. It also introduces a watchdog device structure and the operations that go with it. This is the introduction of this framework. This part supports the minimal watchdog userspace API (or with other words: the functionality to use /dev/watchdog's open, release and write functionality as defined in the simplest watchdog API). Extra functionality will follow in the next set of patches. 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>
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