[PATCH 1/5] watchdog: Create watchdog device in watchdog_dev.c
From: Guenter Roeck
Date: Sun Dec 20 2015 - 16:05:52 EST
The watchdog character device is currently created in watchdog_dev.c,
and the watchdog device in watchdog_core.c. This results in
cross-dependencies, since device creation needs to know the watchdog
character device number as well as the watchdog class, both of which
reside in watchdog_dev.c.
Create the watchdog device in watchdog_dev.c to simplify the code.
Inspired by earlier patch set from Damien Riegel.
Cc: Damien Riegel <damien.riegel@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
drivers/watchdog/watchdog_core.c | 33 ++++--------------
drivers/watchdog/watchdog_core.h | 4 +--
drivers/watchdog/watchdog_dev.c | 73 +++++++++++++++++++++++++++++++++-------
3 files changed, 69 insertions(+), 41 deletions(-)
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index 551af042867c..f0293f7d2b80 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -42,7 +42,6 @@
#include "watchdog_core.h" /* For watchdog_dev_register/... */
static DEFINE_IDA(watchdog_ida);
-static struct class *watchdog_class;
/*
* Deferred Registration infrastructure.
@@ -194,7 +193,7 @@ EXPORT_SYMBOL_GPL(watchdog_set_restart_priority);
static int __watchdog_register_device(struct watchdog_device *wdd)
{
- int ret, id = -1, devno;
+ int ret, id = -1;
if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
return -EINVAL;
@@ -247,16 +246,6 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
}
}
- devno = wdd->cdev.dev;
- wdd->dev = device_create(watchdog_class, wdd->parent, devno,
- wdd, "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;
- }
-
if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) {
wdd->reboot_nb.notifier_call = watchdog_reboot_notifier;
@@ -265,9 +254,7 @@ static int __watchdog_register_device(struct watchdog_device *wdd)
dev_err(wdd->dev, "Cannot register reboot notifier (%d)\n",
ret);
watchdog_dev_unregister(wdd);
- device_destroy(watchdog_class, devno);
ida_simple_remove(&watchdog_ida, wdd->id);
- wdd->dev = NULL;
return ret;
}
}
@@ -311,9 +298,6 @@ EXPORT_SYMBOL_GPL(watchdog_register_device);
static void __watchdog_unregister_device(struct watchdog_device *wdd)
{
- int ret;
- int devno;
-
if (wdd == NULL)
return;
@@ -323,13 +307,8 @@ static void __watchdog_unregister_device(struct watchdog_device *wdd)
if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status))
unregister_reboot_notifier(&wdd->reboot_nb);
- devno = wdd->cdev.dev;
- ret = watchdog_dev_unregister(wdd);
- if (ret)
- pr_err("error unregistering /dev/watchdog (err=%d)\n", ret);
- device_destroy(watchdog_class, devno);
+ watchdog_dev_unregister(wdd);
ida_simple_remove(&watchdog_ida, wdd->id);
- wdd->dev = NULL;
}
/**
@@ -370,9 +349,11 @@ static int __init watchdog_deferred_registration(void)
static int __init watchdog_init(void)
{
- watchdog_class = watchdog_dev_init();
- if (IS_ERR(watchdog_class))
- return PTR_ERR(watchdog_class);
+ int err;
+
+ err = watchdog_dev_init();
+ if (err < 0)
+ return err;
watchdog_deferred_registration();
return 0;
diff --git a/drivers/watchdog/watchdog_core.h b/drivers/watchdog/watchdog_core.h
index 1c8d6b0e68c7..86ff962d1e15 100644
--- a/drivers/watchdog/watchdog_core.h
+++ b/drivers/watchdog/watchdog_core.h
@@ -32,6 +32,6 @@
* Functions/procedures to be called by the core
*/
extern int watchdog_dev_register(struct watchdog_device *);
-extern int watchdog_dev_unregister(struct watchdog_device *);
-extern struct class * __init watchdog_dev_init(void);
+extern void watchdog_dev_unregister(struct watchdog_device *);
+extern int __init watchdog_dev_init(void);
extern void __exit watchdog_dev_exit(void);
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index d93118e97d11..c24392623e98 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -626,17 +626,18 @@ static struct miscdevice watchdog_miscdev = {
};
/*
- * watchdog_dev_register: register a watchdog device
+ * watchdog_cdev_register: register watchdog character device
* @wdd: watchdog device
+ * @devno: character device number
*
- * Register a watchdog device including handling the legacy
+ * Register a watchdog character device including handling the legacy
* /dev/watchdog node. /dev/watchdog is actually a miscdevice and
* thus we set it up like that.
*/
-int watchdog_dev_register(struct watchdog_device *wdd)
+static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno)
{
- int err, devno;
+ int err;
if (wdd->id == 0) {
old_wdd = wdd;
@@ -654,7 +655,6 @@ int watchdog_dev_register(struct watchdog_device *wdd)
}
/* Fill in the data structures */
- devno = MKDEV(MAJOR(watchdog_devt), wdd->id);
cdev_init(&wdd->cdev, &watchdog_fops);
wdd->cdev.owner = wdd->ops->owner;
@@ -672,13 +672,14 @@ int watchdog_dev_register(struct watchdog_device *wdd)
}
/*
- * watchdog_dev_unregister: unregister a watchdog device
+ * watchdog_cdev_unregister: unregister watchdog character device
* @watchdog: watchdog device
*
- * Unregister the watchdog and if needed the legacy /dev/watchdog device.
+ * Unregister watchdog character device and if needed the legacy
+ * /dev/watchdog device.
*/
-int watchdog_dev_unregister(struct watchdog_device *wdd)
+static void watchdog_cdev_unregister(struct watchdog_device *wdd)
{
mutex_lock(&wdd->lock);
set_bit(WDOG_UNREGISTERED, &wdd->status);
@@ -689,7 +690,6 @@ int watchdog_dev_unregister(struct watchdog_device *wdd)
misc_deregister(&watchdog_miscdev);
old_wdd = NULL;
}
- return 0;
}
static struct class watchdog_class = {
@@ -701,29 +701,76 @@ static struct class watchdog_class = {
};
/*
+ * watchdog_dev_register: register a watchdog device
+ * @wdd: watchdog device
+ *
+ * Register a watchdog device including handling the legacy
+ * /dev/watchdog node. /dev/watchdog is actually a miscdevice and
+ * thus we set it up like that.
+ */
+
+int watchdog_dev_register(struct watchdog_device *wdd)
+{
+ struct device *dev;
+ dev_t devno;
+ int ret;
+
+ devno = MKDEV(MAJOR(watchdog_devt), wdd->id);
+
+ ret = watchdog_cdev_register(wdd, devno);
+ if (ret)
+ return ret;
+
+ dev = device_create(&watchdog_class, wdd->parent, devno, wdd,
+ "watchdog%d", wdd->id);
+ if (IS_ERR(dev)) {
+ watchdog_cdev_unregister(wdd);
+ return PTR_ERR(dev);
+ }
+ wdd->dev = dev;
+
+ return ret;
+}
+
+/*
+ * watchdog_dev_unregister: unregister a watchdog device
+ * @watchdog: watchdog device
+ *
+ * Unregister watchdog device and if needed the legacy
+ * /dev/watchdog device.
+ */
+
+void watchdog_dev_unregister(struct watchdog_device *wdd)
+{
+ watchdog_cdev_unregister(wdd);
+ device_destroy(&watchdog_class, wdd->dev->devt);
+ wdd->dev = NULL;
+}
+
+/*
* watchdog_dev_init: init dev part of watchdog core
*
* Allocate a range of chardev nodes to use for watchdog devices
*/
-struct class * __init watchdog_dev_init(void)
+int __init watchdog_dev_init(void)
{
int err;
err = class_register(&watchdog_class);
if (err < 0) {
pr_err("couldn't register class\n");
- return ERR_PTR(err);
+ return err;
}
err = alloc_chrdev_region(&watchdog_devt, 0, MAX_DOGS, "watchdog");
if (err < 0) {
pr_err("watchdog: unable to allocate char dev region\n");
class_unregister(&watchdog_class);
- return ERR_PTR(err);
+ return err;
}
- return &watchdog_class;
+ return 0;
}
/*
--
2.1.4
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