diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/watchdog/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/watchdog/convert_drivers_to_kernel_api.txt | 19 | ||||
| -rw-r--r-- | Documentation/watchdog/watchdog-kernel-api.txt | 10 |
3 files changed, 30 insertions, 1 deletions
diff --git a/Documentation/watchdog/00-INDEX b/Documentation/watchdog/00-INDEX index fc51128071c2..fc9082a1477a 100644 --- a/Documentation/watchdog/00-INDEX +++ b/Documentation/watchdog/00-INDEX @@ -1,5 +1,7 @@ 00-INDEX - this file. +convert_drivers_to_kernel_api.txt + - how-to for converting old watchdog drivers to the new kernel API. hpwdt.txt - information on the HP iLO2 NMI watchdog pcwd-watchdog.txt diff --git a/Documentation/watchdog/convert_drivers_to_kernel_api.txt b/Documentation/watchdog/convert_drivers_to_kernel_api.txt index ae1e90036d06..be8119bb15d2 100644 --- a/Documentation/watchdog/convert_drivers_to_kernel_api.txt +++ b/Documentation/watchdog/convert_drivers_to_kernel_api.txt @@ -163,6 +163,25 @@ Here is a simple example for a watchdog device: +}; +Handle the 'nowayout' feature +----------------------------- + +A few drivers use nowayout statically, i.e. there is no module parameter for it +and only CONFIG_WATCHDOG_NOWAYOUT determines if the feature is going to be +used. This needs to be converted by initializing the status variable of the +watchdog_device like this: + + .status = WATCHDOG_NOWAYOUT_INIT_STATUS, + +Most drivers, however, also allow runtime configuration of nowayout, usually +by adding a module parameter. The conversion for this would be something like: + + watchdog_set_nowayout(&s3c2410_wdd, nowayout); + +The module parameter itself needs to stay, everything else related to nowayout +can go, though. This will likely be some code in open(), close() or write(). + + Register the watchdog device ---------------------------- diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt index 4f7c894244d2..4b93c28e35c6 100644 --- a/Documentation/watchdog/watchdog-kernel-api.txt +++ b/Documentation/watchdog/watchdog-kernel-api.txt @@ -1,6 +1,6 @@ The Linux WatchDog Timer Driver Core kernel API. =============================================== -Last reviewed: 22-Jul-2011 +Last reviewed: 29-Nov-2011 Wim Van Sebroeck <wim@iguana.be> @@ -142,6 +142,14 @@ bit-operations. The status bits that are defined are: * WDOG_NO_WAY_OUT: this bit stores the nowayout setting for the watchdog. If this bit is set then the watchdog timer will not be able to stop. + To set the WDOG_NO_WAY_OUT status bit (before registering your watchdog + timer device) you can either: + * set it statically in your watchdog_device struct with + .status = WATCHDOG_NOWAYOUT_INIT_STATUS, + (this will set the value the same as CONFIG_WATCHDOG_NOWAYOUT) or + * use the following helper function: + static inline void watchdog_set_nowayout(struct watchdog_device *wdd, int nowayout) + Note: The WatchDog Timer Driver Core supports the magic close feature and the nowayout feature. To use the magic close feature you must set the WDIOF_MAGICCLOSE bit in the options field of the watchdog's info structure. |