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authorDaniel Bristot de Oliveira <bristot@kernel.org>2022-02-11 15:30:14 +0100
committerWim Van Sebroeck <wim@linux-watchdog.org>2022-03-27 17:04:08 +0200
commitba6c89ab3b5878364d400b1db4b484e84965f347 (patch)
treeee25edbfa758c29d3084c88193031f6bb275eaf2 /drivers/watchdog
parent4ed1a6b6e66dd9ba0a1d56ed23f46c39fe9368c5 (diff)
downloadlinux-ba6c89ab3b5878364d400b1db4b484e84965f347.tar.bz2
watchdog: Improve watchdog_dev function documentation
Adjust function comments to the kernel doc format. It also adjusts some variable names and adds return values. No functional change. Changes from V1: Change "Returns" to "Return:" (Randy Dunlap) Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: linux-watchdog@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/30378a03e9cd9b5f6e92ec9bf512edc38bad8627.1644589712.git.bristot@kernel.org Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/watchdog_dev.c244
1 files changed, 125 insertions, 119 deletions
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 3a3d8b5c7ad5..54903f3c851e 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -171,17 +171,17 @@ static int __watchdog_ping(struct watchdog_device *wdd)
}
/*
- * watchdog_ping: ping the watchdog.
- * @wdd: the watchdog device to ping
+ * 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.
+ * We only ping when the watchdog device is running.
+ * 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.
- * We only ping when the watchdog device is running.
+ * Return: 0 on success, error otherwise.
*/
-
static int watchdog_ping(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data = wdd->wd_data;
@@ -231,16 +231,14 @@ static enum hrtimer_restart watchdog_timer_expired(struct hrtimer *timer)
}
/*
- * watchdog_start: wrapper to start the watchdog.
- * @wdd: the watchdog device to start
+ * 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.
+ * 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.
+ * Return: 0 on success or a negative errno code for failure.
*/
-
static int watchdog_start(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data = wdd->wd_data;
@@ -274,17 +272,15 @@ static int watchdog_start(struct watchdog_device *wdd)
}
/*
- * watchdog_stop: wrapper to stop the watchdog.
- * @wdd: the watchdog device to stop
+ * 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.
+ * If the 'nowayout' feature was set, the watchdog cannot be stopped.
+ * 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.
- * If the 'nowayout' feature was set, the watchdog cannot be stopped.
+ * Return: 0 on success or a negative errno code for failure.
*/
-
static int watchdog_stop(struct watchdog_device *wdd)
{
int err = 0;
@@ -315,14 +311,14 @@ static int watchdog_stop(struct watchdog_device *wdd)
}
/*
- * watchdog_get_status: wrapper to get the watchdog status
- * @wdd: the watchdog device to get the status from
+ * watchdog_get_status - wrapper to get the watchdog status
+ * @wdd: The watchdog device to get the status from
*
- * The caller must hold wd_data->lock.
+ * Get the watchdog's status flags.
+ * The caller must hold wd_data->lock.
*
- * Get the watchdog's status flags.
+ * Return: watchdog's status flags.
*/
-
static unsigned int watchdog_get_status(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data = wdd->wd_data;
@@ -352,13 +348,14 @@ static unsigned int watchdog_get_status(struct watchdog_device *wdd)
}
/*
- * watchdog_set_timeout: set the watchdog timer timeout
- * @wdd: the watchdog device to set the timeout for
- * @timeout: timeout to set in seconds
+ * 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.
*
- * The caller must hold wd_data->lock.
+ * Return: 0 if successful, error otherwise.
*/
-
static int watchdog_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
@@ -385,11 +382,12 @@ static int watchdog_set_timeout(struct watchdog_device *wdd,
}
/*
- * watchdog_set_pretimeout: set the watchdog timer pretimeout
- * @wdd: the watchdog device to set the timeout for
- * @timeout: pretimeout to set in seconds
+ * watchdog_set_pretimeout - set the watchdog timer pretimeout
+ * @wdd: The watchdog device to set the timeout for
+ * @timeout: pretimeout to set in seconds
+ *
+ * Return: 0 if successful, error otherwise.
*/
-
static int watchdog_set_pretimeout(struct watchdog_device *wdd,
unsigned int timeout)
{
@@ -410,15 +408,15 @@ static int watchdog_set_pretimeout(struct watchdog_device *wdd,
}
/*
- * watchdog_get_timeleft: wrapper to get the time left before a reboot
- * @wdd: the watchdog device to get the remaining time from
- * @timeleft: the time that's left
+ * watchdog_get_timeleft - wrapper to get the time left before a reboot
+ * @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).
+ * The caller must hold wd_data->lock.
*
- * Get the time before a watchdog will reboot (if not pinged).
+ * Return: 0 if successful, error otherwise.
*/
-
static int watchdog_get_timeleft(struct watchdog_device *wdd,
unsigned int *timeleft)
{
@@ -635,14 +633,15 @@ __ATTRIBUTE_GROUPS(wdt);
#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
+ * 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.
+ * The caller must hold wd_data->lock.
+ *
+ * Return: 0 if successful, error otherwise.
*/
-
static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd,
unsigned long arg)
{
@@ -653,17 +652,18 @@ static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd,
}
/*
- * watchdog_write: writes to the watchdog.
- * @file: file from VFS
- * @data: user address of data
- * @len: length of data
- * @ppos: pointer to the file offset
+ * watchdog_write - writes to the watchdog
+ * @file: File from VFS
+ * @data: User address of data
+ * @len: Length of data
+ * @ppos: Pointer to the file offset
*
- * A write to a watchdog device is defined as a keepalive ping.
- * Writing the magic 'V' sequence allows the next close to turn
- * off the watchdog (if 'nowayout' is not set).
+ * A write to a watchdog device is defined as a keepalive ping.
+ * Writing the magic 'V' sequence allows the next close to turn
+ * off the watchdog (if 'nowayout' is not set).
+ *
+ * Return: @len if successful, error otherwise.
*/
-
static ssize_t watchdog_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
@@ -706,13 +706,15 @@ static ssize_t watchdog_write(struct file *file, const char __user *data,
}
/*
- * watchdog_ioctl: handle the different ioctl's for the watchdog device.
- * @file: file handle to the device
- * @cmd: watchdog command
- * @arg: argument pointer
+ * watchdog_ioctl - handle the different ioctl's for the watchdog device
+ * @file: File handle to the device
+ * @cmd: Watchdog command
+ * @arg: Argument pointer
*
- * The watchdog API defines a common set of functions for all watchdogs
- * according to their available features.
+ * The watchdog API defines a common set of functions for all watchdogs
+ * according to their available features.
+ *
+ * Return: 0 if successful, error otherwise.
*/
static long watchdog_ioctl(struct file *file, unsigned int cmd,
@@ -819,15 +821,16 @@ out_ioctl:
}
/*
- * watchdog_open: open the /dev/watchdog* devices.
- * @inode: inode of device
- * @file: file handle to device
+ * watchdog_open - open the /dev/watchdog* devices
+ * @inode: Inode of device
+ * @file: File handle to device
+ *
+ * When the /dev/watchdog* device gets opened, we start the watchdog.
+ * Watch out: the /dev/watchdog device is single open, so we make sure
+ * it can only be opened once.
*
- * When the /dev/watchdog* device gets opened, we start the watchdog.
- * Watch out: the /dev/watchdog device is single open, so we make sure
- * it can only be opened once.
+ * Return: 0 if successful, error otherwise.
*/
-
static int watchdog_open(struct inode *inode, struct file *file)
{
struct watchdog_core_data *wd_data;
@@ -896,15 +899,16 @@ static void watchdog_core_data_release(struct device *dev)
}
/*
- * watchdog_release: release the watchdog device.
- * @inode: inode of device
- * @file: file handle to device
+ * watchdog_release - release the watchdog device
+ * @inode: Inode of device
+ * @file: File handle to device
+ *
+ * This is the code for when /dev/watchdog gets closed. We will only
+ * stop the watchdog when we have received the magic char (and nowayout
+ * was not set), else the watchdog will keep running.
*
- * This is the code for when /dev/watchdog gets closed. We will only
- * stop the watchdog when we have received the magic char (and nowayout
- * was not set), else the watchdog will keep running.
+ * Always returns 0.
*/
-
static int watchdog_release(struct inode *inode, struct file *file)
{
struct watchdog_core_data *wd_data = file->private_data;
@@ -977,14 +981,15 @@ static struct class watchdog_class = {
};
/*
- * watchdog_cdev_register: register watchdog character device
- * @wdd: watchdog device
+ * watchdog_cdev_register - register watchdog character device
+ * @wdd: Watchdog device
+ *
+ * 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.
*
- * 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.
+ * Return: 0 if successful, error otherwise.
*/
-
static int watchdog_cdev_register(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data;
@@ -1074,13 +1079,12 @@ static int watchdog_cdev_register(struct watchdog_device *wdd)
}
/*
- * watchdog_cdev_unregister: unregister watchdog character device
- * @watchdog: watchdog device
+ * watchdog_cdev_unregister - unregister watchdog character device
+ * @wdd: Watchdog device
*
- * Unregister watchdog character device and if needed the legacy
- * /dev/watchdog device.
+ * Unregister watchdog character device and if needed the legacy
+ * /dev/watchdog device.
*/
-
static void watchdog_cdev_unregister(struct watchdog_device *wdd)
{
struct watchdog_core_data *wd_data = wdd->wd_data;
@@ -1109,15 +1113,16 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd)
put_device(&wd_data->dev);
}
-/*
- * watchdog_dev_register: register a watchdog device
- * @wdd: watchdog device
+/**
+ * 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.
*
- * 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.
+ * Return: 0 if successful, error otherwise.
*/
-
int watchdog_dev_register(struct watchdog_device *wdd)
{
int ret;
@@ -1133,30 +1138,31 @@ int watchdog_dev_register(struct watchdog_device *wdd)
return ret;
}
-/*
- * watchdog_dev_unregister: unregister a watchdog device
- * @watchdog: watchdog device
+/**
+ * watchdog_dev_unregister - unregister a watchdog device
+ * @wdd: watchdog device
*
- * Unregister watchdog device and if needed the legacy
- * /dev/watchdog device.
+ * Unregister watchdog device and if needed the legacy
+ * /dev/watchdog device.
*/
-
void watchdog_dev_unregister(struct watchdog_device *wdd)
{
watchdog_unregister_pretimeout(wdd);
watchdog_cdev_unregister(wdd);
}
-/*
- * watchdog_set_last_hw_keepalive: set last HW keepalive time for watchdog
- * @wdd: watchdog device
- * @last_ping_ms: time since last HW heartbeat
+/**
+ * watchdog_set_last_hw_keepalive - set last HW keepalive time for watchdog
+ * @wdd: Watchdog device
+ * @last_ping_ms: Time since last HW heartbeat
*
- * Adjusts the last known HW keepalive time for a watchdog timer.
- * This is needed if the watchdog is already running when the probe
- * function is called, and it can't be pinged immediately. This
- * function must be called immediately after watchdog registration,
- * and min_hw_heartbeat_ms must be set for this to be useful.
+ * Adjusts the last known HW keepalive time for a watchdog timer.
+ * This is needed if the watchdog is already running when the probe
+ * function is called, and it can't be pinged immediately. This
+ * function must be called immediately after watchdog registration,
+ * and min_hw_heartbeat_ms must be set for this to be useful.
+ *
+ * Return: 0 if successful, error otherwise.
*/
int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd,
unsigned int last_ping_ms)
@@ -1180,12 +1186,13 @@ int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd,
}
EXPORT_SYMBOL_GPL(watchdog_set_last_hw_keepalive);
-/*
- * watchdog_dev_init: init dev part of watchdog core
+/**
+ * watchdog_dev_init - init dev part of watchdog core
*
- * Allocate a range of chardev nodes to use for watchdog devices
+ * Allocate a range of chardev nodes to use for watchdog devices.
+ *
+ * Return: 0 if successful, error otherwise.
*/
-
int __init watchdog_dev_init(void)
{
int err;
@@ -1218,12 +1225,11 @@ err_register:
return err;
}
-/*
- * watchdog_dev_exit: exit dev part of watchdog core
+/**
+ * watchdog_dev_exit - exit dev part of watchdog core
*
- * Release the range of chardev nodes used for watchdog devices
+ * Release the range of chardev nodes used for watchdog devices.
*/
-
void __exit watchdog_dev_exit(void)
{
unregister_chrdev_region(watchdog_devt, MAX_DOGS);