diff options
Diffstat (limited to 'drivers/watchdog/watchdog_core.c')
| -rw-r--r-- | drivers/watchdog/watchdog_core.c | 74 |
1 files changed, 70 insertions, 4 deletions
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index 14d768bfa26..6aa46a90ff0 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -34,8 +34,13 @@ #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 <linux/err.h> /* For IS_ERR macros */ -#include "watchdog_dev.h" /* For watchdog_dev_register/... */ +#include "watchdog_core.h" /* For watchdog_dev_register/... */ + +static DEFINE_IDA(watchdog_ida); +static struct class *watchdog_class; /** * watchdog_register_device() - register a watchdog device @@ -49,7 +54,7 @@ */ int watchdog_register_device(struct watchdog_device *wdd) { - int ret; + int ret, id, devno; if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL) return -EINVAL; @@ -74,10 +79,38 @@ 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 */ + mutex_init(&wdd->lock); + 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); + 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; + } + } + + devno = wdd->cdev.dev; + wdd->dev = device_create(watchdog_class, wdd->parent, devno, + NULL, "watchdog%d", wdd->id); + if (IS_ERR(wdd->dev)) { + watchdog_dev_unregister(wdd); + ida_simple_remove(&watchdog_ida, id); + ret = PTR_ERR(wdd->dev); return ret; } @@ -95,6 +128,7 @@ EXPORT_SYMBOL_GPL(watchdog_register_device); void watchdog_unregister_device(struct watchdog_device *wdd) { int ret; + int devno = wdd->cdev.dev; if (wdd == NULL) return; @@ -102,9 +136,41 @@ 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); + device_destroy(watchdog_class, devno); + ida_simple_remove(&watchdog_ida, wdd->id); + wdd->dev = NULL; } EXPORT_SYMBOL_GPL(watchdog_unregister_device); +static int __init watchdog_init(void) +{ + int err; + + watchdog_class = class_create(THIS_MODULE, "watchdog"); + if (IS_ERR(watchdog_class)) { + pr_err("couldn't create class\n"); + return PTR_ERR(watchdog_class); + } + + err = watchdog_dev_init(); + if (err < 0) { + class_destroy(watchdog_class); + return err; + } + + return 0; +} + +static void __exit watchdog_exit(void) +{ + watchdog_dev_exit(); + class_destroy(watchdog_class); + 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"); |