Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-block

[firefly-linux-kernel-4.4.55.git] / drivers / watchdog / watchdog_core.c

diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 14d768bfa267d78923a467484ed1f66275471bb2..6aa46a90ff028691f97627765f593d864bc885a1 100644 (file)
--- 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");