#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#include <linux/module.h> /* For module stuff/... */
-#include <linux/types.h> /* For standard types (like size_t) */
+#include <linux/cdev.h> /* For character device */
#include <linux/errno.h> /* For the -ENODEV/... values */
-#include <linux/kernel.h> /* For printk/panic/... */
#include <linux/fs.h> /* For file operations */
-#include <linux/watchdog.h> /* For watchdog specific items */
-#include <linux/miscdevice.h> /* For handling misc devices */
#include <linux/init.h> /* For __init/__exit/... */
+#include <linux/kernel.h> /* For printk/panic/... */
+#include <linux/kref.h> /* For data references */
+#include <linux/miscdevice.h> /* For handling misc devices */
+#include <linux/module.h> /* For module stuff/... */
+#include <linux/mutex.h> /* For mutexes */
+#include <linux/slab.h> /* For memory functions */
+#include <linux/types.h> /* For standard types (like size_t) */
+#include <linux/watchdog.h> /* For watchdog specific items */
#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
#include "watchdog_core.h"
+/*
+ * struct watchdog_core_data - watchdog core internal data
+ * @kref: Reference count.
+ * @cdev: The watchdog's Character device.
+ * @wdd: Pointer to watchdog device.
+ * @lock: Lock for watchdog core.
+ * @status: Watchdog core internal status bits.
+ */
+struct watchdog_core_data {
+ struct kref kref;
+ struct cdev cdev;
+ struct watchdog_device *wdd;
+ struct mutex lock;
+ unsigned long status; /* Internal status bits */
+#define _WDOG_DEV_OPEN 0 /* Opened ? */
+#define _WDOG_ALLOW_RELEASE 1 /* Did we receive the magic char ? */
+};
+
/* the dev_t structure to store the dynamically allocated watchdog devices */
static dev_t watchdog_devt;
-/* the watchdog device behind /dev/watchdog */
-static struct watchdog_device *old_wdd;
+/* Reference to watchdog device behind /dev/watchdog */
+static struct watchdog_core_data *old_wd_data;
/*
* watchdog_ping: ping the watchdog.
* @wdd: the watchdog device to ping
*
+ * The caller must hold wd_data->lock.
+ *
* If the watchdog has no own ping operation then it needs to be
* restarted via the start operation. This wrapper function does
* exactly that.
static int watchdog_ping(struct watchdog_device *wdd)
{
- int err = 0;
-
- mutex_lock(&wdd->lock);
-
- if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
- err = -ENODEV;
- goto out_ping;
- }
+ int err;
if (!watchdog_active(wdd))
- goto out_ping;
+ return 0;
if (wdd->ops->ping)
err = wdd->ops->ping(wdd); /* ping the watchdog */
else
err = wdd->ops->start(wdd); /* restart watchdog */
-out_ping:
- mutex_unlock(&wdd->lock);
return err;
}
* watchdog_start: wrapper to start the watchdog.
* @wdd: the watchdog device to start
*
+ * The caller must hold wd_data->lock.
+ *
* Start the watchdog if it is not active and mark it active.
* This function returns zero on success or a negative errno code for
* failure.
static int watchdog_start(struct watchdog_device *wdd)
{
- int err = 0;
-
- mutex_lock(&wdd->lock);
-
- if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
- err = -ENODEV;
- goto out_start;
- }
+ int err;
if (watchdog_active(wdd))
- goto out_start;
+ return 0;
err = wdd->ops->start(wdd);
if (err == 0)
set_bit(WDOG_ACTIVE, &wdd->status);
-out_start:
- mutex_unlock(&wdd->lock);
return err;
}
* watchdog_stop: wrapper to stop the watchdog.
* @wdd: the watchdog device to stop
*
+ * The caller must hold wd_data->lock.
+ *
* Stop the watchdog if it is still active and unmark it active.
* This function returns zero on success or a negative errno code for
* failure.
static int watchdog_stop(struct watchdog_device *wdd)
{
- int err = 0;
-
- mutex_lock(&wdd->lock);
-
- if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
- err = -ENODEV;
- goto out_stop;
- }
+ int err;
if (!watchdog_active(wdd))
- goto out_stop;
+ return 0;
if (test_bit(WDOG_NO_WAY_OUT, &wdd->status)) {
dev_info(wdd->dev, "nowayout prevents watchdog being stopped!\n");
- err = -EBUSY;
- goto out_stop;
+ return -EBUSY;
}
err = wdd->ops->stop(wdd);
if (err == 0)
clear_bit(WDOG_ACTIVE, &wdd->status);
-out_stop:
- mutex_unlock(&wdd->lock);
return err;
}
/*
* watchdog_get_status: wrapper to get the watchdog status
* @wdd: the watchdog device to get the status from
- * @status: the status of the watchdog device
+ *
+ * The caller must hold wd_data->lock.
*
* Get the watchdog's status flags.
*/
-static int watchdog_get_status(struct watchdog_device *wdd,
- unsigned int *status)
+static unsigned int watchdog_get_status(struct watchdog_device *wdd)
{
- int err = 0;
-
- *status = 0;
if (!wdd->ops->status)
- return -EOPNOTSUPP;
-
- mutex_lock(&wdd->lock);
-
- if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
- err = -ENODEV;
- goto out_status;
- }
-
- *status = wdd->ops->status(wdd);
+ return 0;
-out_status:
- mutex_unlock(&wdd->lock);
- return err;
+ return wdd->ops->status(wdd);
}
/*
* watchdog_set_timeout: set the watchdog timer timeout
* @wdd: the watchdog device to set the timeout for
* @timeout: timeout to set in seconds
+ *
+ * The caller must hold wd_data->lock.
*/
static int watchdog_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
- int err;
-
if (!wdd->ops->set_timeout || !(wdd->info->options & WDIOF_SETTIMEOUT))
return -EOPNOTSUPP;
if (watchdog_timeout_invalid(wdd, timeout))
return -EINVAL;
- mutex_lock(&wdd->lock);
-
- if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
- err = -ENODEV;
- goto out_timeout;
- }
-
- err = wdd->ops->set_timeout(wdd, timeout);
-
-out_timeout:
- mutex_unlock(&wdd->lock);
- return err;
+ return wdd->ops->set_timeout(wdd, timeout);
}
/*
* @wdd: the watchdog device to get the remaining time from
* @timeleft: the time that's left
*
+ * The caller must hold wd_data->lock.
+ *
* Get the time before a watchdog will reboot (if not pinged).
*/
static int watchdog_get_timeleft(struct watchdog_device *wdd,
unsigned int *timeleft)
{
- int err = 0;
-
*timeleft = 0;
+
if (!wdd->ops->get_timeleft)
return -EOPNOTSUPP;
- mutex_lock(&wdd->lock);
+ *timeleft = wdd->ops->get_timeleft(wdd);
- if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
- err = -ENODEV;
- goto out_timeleft;
- }
+ return 0;
+}
- *timeleft = wdd->ops->get_timeleft(wdd);
+#ifdef CONFIG_WATCHDOG_SYSFS
+static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
-out_timeleft:
- mutex_unlock(&wdd->lock);
- return err;
+ return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status));
+}
+static DEVICE_ATTR_RO(nowayout);
+
+static ssize_t status_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ struct watchdog_core_data *wd_data = wdd->wd_data;
+ unsigned int status;
+
+ mutex_lock(&wd_data->lock);
+ status = watchdog_get_status(wdd);
+ mutex_unlock(&wd_data->lock);
+
+ return sprintf(buf, "%u\n", status);
+}
+static DEVICE_ATTR_RO(status);
+
+static ssize_t bootstatus_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", wdd->bootstatus);
+}
+static DEVICE_ATTR_RO(bootstatus);
+
+static ssize_t timeleft_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ struct watchdog_core_data *wd_data = wdd->wd_data;
+ ssize_t status;
+ unsigned int val;
+
+ mutex_lock(&wd_data->lock);
+ status = watchdog_get_timeleft(wdd, &val);
+ mutex_unlock(&wd_data->lock);
+ if (!status)
+ status = sprintf(buf, "%u\n", val);
+
+ return status;
}
+static DEVICE_ATTR_RO(timeleft);
+
+static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", wdd->timeout);
+}
+static DEVICE_ATTR_RO(timeout);
+
+static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%s\n", wdd->info->identity);
+}
+static DEVICE_ATTR_RO(identity);
+
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+ if (watchdog_active(wdd))
+ return sprintf(buf, "active\n");
+
+ return sprintf(buf, "inactive\n");
+}
+static DEVICE_ATTR_RO(state);
+
+static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
+ int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct watchdog_device *wdd = dev_get_drvdata(dev);
+ umode_t mode = attr->mode;
+
+ if (attr == &dev_attr_status.attr && !wdd->ops->status)
+ mode = 0;
+ else if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft)
+ mode = 0;
+
+ return mode;
+}
+static struct attribute *wdt_attrs[] = {
+ &dev_attr_state.attr,
+ &dev_attr_identity.attr,
+ &dev_attr_timeout.attr,
+ &dev_attr_timeleft.attr,
+ &dev_attr_bootstatus.attr,
+ &dev_attr_status.attr,
+ &dev_attr_nowayout.attr,
+ NULL,
+};
+
+static const struct attribute_group wdt_group = {
+ .attrs = wdt_attrs,
+ .is_visible = wdt_is_visible,
+};
+__ATTRIBUTE_GROUPS(wdt);
+#else
+#define wdt_groups NULL
+#endif
/*
* watchdog_ioctl_op: call the watchdog drivers ioctl op if defined
* @wdd: the watchdog device to do the ioctl on
* @cmd: watchdog command
* @arg: argument pointer
+ *
+ * The caller must hold wd_data->lock.
*/
static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd,
unsigned long arg)
{
- int err;
-
if (!wdd->ops->ioctl)
return -ENOIOCTLCMD;
- mutex_lock(&wdd->lock);
-
- if (test_bit(WDOG_UNREGISTERED, &wdd->status)) {
- err = -ENODEV;
- goto out_ioctl;
- }
-
- err = wdd->ops->ioctl(wdd, cmd, arg);
-
-out_ioctl:
- mutex_unlock(&wdd->lock);
- return err;
+ return wdd->ops->ioctl(wdd, cmd, arg);
}
/*
static ssize_t watchdog_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
- struct watchdog_device *wdd = file->private_data;
+ struct watchdog_core_data *wd_data = file->private_data;
+ struct watchdog_device *wdd;
+ int err;
size_t i;
char c;
- int err;
if (len == 0)
return 0;
* Note: just in case someone wrote the magic character
* five months ago...
*/
- clear_bit(WDOG_ALLOW_RELEASE, &wdd->status);
+ clear_bit(_WDOG_ALLOW_RELEASE, &wd_data->status);
/* scan to see whether or not we got the magic character */
for (i = 0; i != len; i++) {
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
- set_bit(WDOG_ALLOW_RELEASE, &wdd->status);
+ set_bit(_WDOG_ALLOW_RELEASE, &wd_data->status);
}
/* someone wrote to us, so we send the watchdog a keepalive ping */
- err = watchdog_ping(wdd);
+
+ err = -ENODEV;
+ mutex_lock(&wd_data->lock);
+ wdd = wd_data->wdd;
+ if (wdd)
+ err = watchdog_ping(wdd);
+ mutex_unlock(&wd_data->lock);
+
if (err < 0)
return err;
static long watchdog_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
- struct watchdog_device *wdd = file->private_data;
+ struct watchdog_core_data *wd_data = file->private_data;
void __user *argp = (void __user *)arg;
+ struct watchdog_device *wdd;
int __user *p = argp;
unsigned int val;
int err;
+ mutex_lock(&wd_data->lock);
+
+ wdd = wd_data->wdd;
+ if (!wdd) {
+ err = -ENODEV;
+ goto out_ioctl;
+ }
+
err = watchdog_ioctl_op(wdd, cmd, arg);
if (err != -ENOIOCTLCMD)
- return err;
+ goto out_ioctl;
switch (cmd) {
case WDIOC_GETSUPPORT:
- return copy_to_user(argp, wdd->info,
+ err = copy_to_user(argp, wdd->info,
sizeof(struct watchdog_info)) ? -EFAULT : 0;
+ break;
case WDIOC_GETSTATUS:
- err = watchdog_get_status(wdd, &val);
- if (err == -ENODEV)
- return err;
- return put_user(val, p);
+ val = watchdog_get_status(wdd);
+ err = put_user(val, p);
+ break;
case WDIOC_GETBOOTSTATUS:
- return put_user(wdd->bootstatus, p);
+ err = put_user(wdd->bootstatus, p);
+ break;
case WDIOC_SETOPTIONS:
- if (get_user(val, p))
- return -EFAULT;
+ if (get_user(val, p)) {
+ err = -EFAULT;
+ break;
+ }
if (val & WDIOS_DISABLECARD) {
err = watchdog_stop(wdd);
if (err < 0)
- return err;
+ break;
}
- if (val & WDIOS_ENABLECARD) {
+ if (val & WDIOS_ENABLECARD)
err = watchdog_start(wdd);
- if (err < 0)
- return err;
- }
- return 0;
+ break;
case WDIOC_KEEPALIVE:
- if (!(wdd->info->options & WDIOF_KEEPALIVEPING))
- return -EOPNOTSUPP;
- return watchdog_ping(wdd);
+ if (!(wdd->info->options & WDIOF_KEEPALIVEPING)) {
+ err = -EOPNOTSUPP;
+ break;
+ }
+ err = watchdog_ping(wdd);
+ break;
case WDIOC_SETTIMEOUT:
- if (get_user(val, p))
- return -EFAULT;
+ if (get_user(val, p)) {
+ err = -EFAULT;
+ break;
+ }
err = watchdog_set_timeout(wdd, val);
if (err < 0)
- return err;
+ break;
/* If the watchdog is active then we send a keepalive ping
* to make sure that the watchdog keep's running (and if
* possible that it takes the new timeout) */
err = watchdog_ping(wdd);
if (err < 0)
- return err;
+ break;
/* Fall */
case WDIOC_GETTIMEOUT:
/* timeout == 0 means that we don't know the timeout */
- if (wdd->timeout == 0)
- return -EOPNOTSUPP;
- return put_user(wdd->timeout, p);
+ if (wdd->timeout == 0) {
+ err = -EOPNOTSUPP;
+ break;
+ }
+ err = put_user(wdd->timeout, p);
+ break;
case WDIOC_GETTIMELEFT:
err = watchdog_get_timeleft(wdd, &val);
- if (err)
- return err;
- return put_user(val, p);
+ if (err < 0)
+ break;
+ err = put_user(val, p);
+ break;
default:
- return -ENOTTY;
+ err = -ENOTTY;
+ break;
}
+
+out_ioctl:
+ mutex_unlock(&wd_data->lock);
+ return err;
}
/*
static int watchdog_open(struct inode *inode, struct file *file)
{
- int err = -EBUSY;
+ struct watchdog_core_data *wd_data;
struct watchdog_device *wdd;
+ int err;
/* Get the corresponding watchdog device */
if (imajor(inode) == MISC_MAJOR)
- wdd = old_wdd;
+ wd_data = old_wd_data;
else
- wdd = container_of(inode->i_cdev, struct watchdog_device, cdev);
+ wd_data = container_of(inode->i_cdev, struct watchdog_core_data,
+ cdev);
/* the watchdog is single open! */
- if (test_and_set_bit(WDOG_DEV_OPEN, &wdd->status))
+ if (test_and_set_bit(_WDOG_DEV_OPEN, &wd_data->status))
return -EBUSY;
+ wdd = wd_data->wdd;
+
/*
* If the /dev/watchdog device is open, we don't want the module
* to be unloaded.
*/
- if (!try_module_get(wdd->ops->owner))
- goto out;
+ if (!try_module_get(wdd->ops->owner)) {
+ err = -EBUSY;
+ goto out_clear;
+ }
err = watchdog_start(wdd);
if (err < 0)
goto out_mod;
- file->private_data = wdd;
+ file->private_data = wd_data;
- if (wdd->ops->ref)
- wdd->ops->ref(wdd);
+ kref_get(&wd_data->kref);
/* dev/watchdog is a virtual (and thus non-seekable) filesystem */
return nonseekable_open(inode, file);
out_mod:
- module_put(wdd->ops->owner);
-out:
- clear_bit(WDOG_DEV_OPEN, &wdd->status);
+ module_put(wd_data->wdd->ops->owner);
+out_clear:
+ clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
return err;
}
+static void watchdog_core_data_release(struct kref *kref)
+{
+ struct watchdog_core_data *wd_data;
+
+ wd_data = container_of(kref, struct watchdog_core_data, kref);
+
+ kfree(wd_data);
+}
+
/*
* watchdog_release: release the watchdog device.
* @inode: inode of device
static int watchdog_release(struct inode *inode, struct file *file)
{
- struct watchdog_device *wdd = file->private_data;
+ struct watchdog_core_data *wd_data = file->private_data;
+ struct watchdog_device *wdd;
int err = -EBUSY;
+ mutex_lock(&wd_data->lock);
+
+ wdd = wd_data->wdd;
+ if (!wdd)
+ goto done;
+
/*
* We only stop the watchdog if we received the magic character
* or if WDIOF_MAGICCLOSE is not set. If nowayout was set then
*/
if (!test_bit(WDOG_ACTIVE, &wdd->status))
err = 0;
- else if (test_and_clear_bit(WDOG_ALLOW_RELEASE, &wdd->status) ||
+ else if (test_and_clear_bit(_WDOG_ALLOW_RELEASE, &wd_data->status) ||
!(wdd->info->options & WDIOF_MAGICCLOSE))
err = watchdog_stop(wdd);
/* If the watchdog was not stopped, send a keepalive ping */
if (err < 0) {
- mutex_lock(&wdd->lock);
- if (!test_bit(WDOG_UNREGISTERED, &wdd->status))
- dev_crit(wdd->dev, "watchdog did not stop!\n");
- mutex_unlock(&wdd->lock);
+ dev_crit(wdd->dev, "watchdog did not stop!\n");
watchdog_ping(wdd);
}
- /* Allow the owner module to be unloaded again */
- module_put(wdd->ops->owner);
-
/* make sure that /dev/watchdog can be re-opened */
- clear_bit(WDOG_DEV_OPEN, &wdd->status);
-
- /* Note wdd may be gone after this, do not use after this! */
- if (wdd->ops->unref)
- wdd->ops->unref(wdd);
+ clear_bit(_WDOG_DEV_OPEN, &wd_data->status);
+done:
+ mutex_unlock(&wd_data->lock);
+ /* Allow the owner module to be unloaded again */
+ module_put(wd_data->cdev.owner);
+ kref_put(&wd_data->kref, watchdog_core_data_release);
return 0;
}
};
/*
- * 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;
+ struct watchdog_core_data *wd_data;
+ int err;
+
+ wd_data = kzalloc(sizeof(struct watchdog_core_data), GFP_KERNEL);
+ if (!wd_data)
+ return -ENOMEM;
+ kref_init(&wd_data->kref);
+ mutex_init(&wd_data->lock);
+
+ wd_data->wdd = wdd;
+ wdd->wd_data = wd_data;
if (wdd->id == 0) {
- old_wdd = wdd;
+ old_wd_data = wd_data;
watchdog_miscdev.parent = wdd->parent;
err = misc_register(&watchdog_miscdev);
if (err != 0) {
if (err == -EBUSY)
pr_err("%s: a legacy watchdog module is probably present.\n",
wdd->info->identity);
- old_wdd = NULL;
+ old_wd_data = NULL;
+ kfree(wd_data);
return err;
}
}
/* Fill in the data structures */
- devno = MKDEV(MAJOR(watchdog_devt), wdd->id);
- cdev_init(&wdd->cdev, &watchdog_fops);
- wdd->cdev.owner = wdd->ops->owner;
+ cdev_init(&wd_data->cdev, &watchdog_fops);
+ wd_data->cdev.owner = wdd->ops->owner;
/* Add the device */
- err = cdev_add(&wdd->cdev, devno, 1);
+ err = cdev_add(&wd_data->cdev, devno, 1);
if (err) {
pr_err("watchdog%d unable to add device %d:%d\n",
wdd->id, MAJOR(watchdog_devt), wdd->id);
if (wdd->id == 0) {
misc_deregister(&watchdog_miscdev);
- old_wdd = NULL;
+ old_wd_data = NULL;
+ kref_put(&wd_data->kref, watchdog_core_data_release);
}
}
return err;
}
/*
- * 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);
- mutex_unlock(&wdd->lock);
+ struct watchdog_core_data *wd_data = wdd->wd_data;
- cdev_del(&wdd->cdev);
+ cdev_del(&wd_data->cdev);
if (wdd->id == 0) {
misc_deregister(&watchdog_miscdev);
- old_wdd = NULL;
+ old_wd_data = NULL;
}
- return 0;
+
+ mutex_lock(&wd_data->lock);
+ wd_data->wdd = NULL;
+ wdd->wd_data = NULL;
+ mutex_unlock(&wd_data->lock);
+
+ kref_put(&wd_data->kref, watchdog_core_data_release);
+}
+
+static struct class watchdog_class = {
+ .name = "watchdog",
+ .owner = THIS_MODULE,
+ .dev_groups = wdt_groups,
+};
+
+/*
+ * 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)
+{
+ device_destroy(&watchdog_class, wdd->dev->devt);
+ wdd->dev = NULL;
+ watchdog_cdev_unregister(wdd);
}
/*
int __init watchdog_dev_init(void)
{
- int err = alloc_chrdev_region(&watchdog_devt, 0, MAX_DOGS, "watchdog");
- if (err < 0)
+ int err;
+
+ err = class_register(&watchdog_class);
+ if (err < 0) {
+ pr_err("couldn't register class\n");
+ 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");
- return err;
+ class_unregister(&watchdog_class);
+ return err;
+ }
+
+ return 0;
}
/*
void __exit watchdog_dev_exit(void)
{
unregister_chrdev_region(watchdog_devt, MAX_DOGS);
+ class_unregister(&watchdog_class);
}
projects / karo-tx-linux.git / blobdiff