diff options
| author | Alan Cox <alan@linux.intel.com> | 2012-05-10 21:48:59 +0200 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2012-05-30 07:54:25 +0200 |
| commit | 45f5fed30a6460ec58f159ff297a2974153a97de (patch) | |
| tree | d173b2d22ed1187fb7ed2cb85015ddf5c545da05 /drivers/watchdog/watchdog_core.c | |
| parent | fb5f6658163412dce22724e906e324ab7fd62c18 (diff) | |
| download | linux-45f5fed30a6460ec58f159ff297a2974153a97de.tar.bz2 | |
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>
Diffstat (limited to 'drivers/watchdog/watchdog_core.c')
| -rw-r--r-- | drivers/watchdog/watchdog_core.c | 43 |
1 files changed, 39 insertions, 4 deletions
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index 8598308278d3..5f9879369003 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -34,9 +34,12 @@ #include <linux/kernel.h> /* For printk/panic/... */ #include <linux/watchdog.h> /* For watchdog specific items */ #include <linux/init.h> /* For __init/__exit/... */ +#include <linux/idr.h> /* For ida_* macros */ #include "watchdog_core.h" /* For watchdog_dev_register/... */ +static DEFINE_IDA(watchdog_ida); + /** * watchdog_register_device() - register a watchdog device * @wdd: watchdog device @@ -49,7 +52,7 @@ */ int watchdog_register_device(struct watchdog_device *wdd) { - int ret; + int ret, id; if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL) return -EINVAL; @@ -74,11 +77,28 @@ int watchdog_register_device(struct watchdog_device *wdd) * corrupted in a later stage then we expect a kernel panic! */ - /* We only support 1 watchdog device via the /dev/watchdog interface */ + id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL); + if (id < 0) + return id; + wdd->id = id; + ret = watchdog_dev_register(wdd); if (ret) { - pr_err("error registering /dev/watchdog (err=%d)\n", ret); - return ret; + ida_simple_remove(&watchdog_ida, id); + if (!(id == 0 && ret == -EBUSY)) + return ret; + + /* Retry in case a legacy watchdog module exists */ + id = ida_simple_get(&watchdog_ida, 1, MAX_DOGS, GFP_KERNEL); + if (id < 0) + return id; + wdd->id = id; + + ret = watchdog_dev_register(wdd); + if (ret) { + ida_simple_remove(&watchdog_ida, id); + return ret; + } } return 0; @@ -102,9 +122,24 @@ void watchdog_unregister_device(struct watchdog_device *wdd) ret = watchdog_dev_unregister(wdd); if (ret) pr_err("error unregistering /dev/watchdog (err=%d)\n", ret); + ida_simple_remove(&watchdog_ida, wdd->id); } EXPORT_SYMBOL_GPL(watchdog_unregister_device); +static int __init watchdog_init(void) +{ + return watchdog_dev_init(); +} + +static void __exit watchdog_exit(void) +{ + watchdog_dev_exit(); + ida_destroy(&watchdog_ida); +} + +subsys_initcall(watchdog_init); +module_exit(watchdog_exit); + MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>"); MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>"); MODULE_DESCRIPTION("WatchDog Timer Driver Core"); |