[PATCH v3 1/2] watchdog: add WDIOC_SETPRETIMEOUT and WDIOC_GETPRETIMEOUT
Robin Gong
b38343 at freescale.com
Tue Nov 3 00:26:45 PST 2015
Since the watchdog common framework centrialize the IOCTL interfaces of
device driver now, the SETPRETIMEOUT and GETPRETIMEOUT need to be added
in the common code.
Signed-off-by: Robin Gong <b38343 at freescale.com>
---
Documentation/watchdog/watchdog-kernel-api.txt | 12 +++++++++
drivers/watchdog/watchdog_dev.c | 37 ++++++++++++++++++++++++++
include/linux/watchdog.h | 11 ++++++++
3 files changed, 60 insertions(+)
diff --git a/Documentation/watchdog/watchdog-kernel-api.txt b/Documentation/watchdog/watchdog-kernel-api.txt
index d8b0d33..20aa841 100644
--- a/Documentation/watchdog/watchdog-kernel-api.txt
+++ b/Documentation/watchdog/watchdog-kernel-api.txt
@@ -51,6 +51,7 @@ struct watchdog_device {
const struct watchdog_ops *ops;
unsigned int bootstatus;
unsigned int timeout;
+ unsigned int pretimeout;
unsigned int min_timeout;
unsigned int max_timeout;
void *driver_data;
@@ -73,6 +74,7 @@ It contains following fields:
additional information about the watchdog timer itself. (Like it's unique name)
* ops: a pointer to the list of watchdog operations that the watchdog supports.
* timeout: the watchdog timer's timeout value (in seconds).
+* pretimeout: The watchdog devices pre_timeout value.
* min_timeout: the watchdog timer's minimum timeout value (in seconds).
* max_timeout: the watchdog timer's maximum timeout value (in seconds).
* bootstatus: status of the device after booting (reported with watchdog
@@ -99,6 +101,7 @@ struct watchdog_ops {
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
+ int (*set_pretimeout)(struct watchdog_device *, unsigned int);
unsigned int (*get_timeleft)(struct watchdog_device *);
void (*ref)(struct watchdog_device *);
void (*unref)(struct watchdog_device *);
@@ -163,6 +166,15 @@ they are supported. These optional routines/operations are:
because the watchdog does not necessarily has a 1 second resolution).
(Note: the WDIOF_SETTIMEOUT needs to be set in the options field of the
watchdog's info structure).
+* set_pretimeout: this routine check and changes the pre_timeout value of
+ the watchdog, because some watchdog device can trigger the pre_timeout
+ interrupt before watchdog timeout event happened, so that we have chance
+ to save some critical information or something else before watchdog
+ triggered. The pre_timeout value means the number of seconds before
+ watchdog timeout.It returns 0 on success, -EINVAL for "parameter out
+ of range" and and -EIO for "could not write value to the watchdog".
+ (Note: the WDIOF_SETPRETIMEOUT needs to be set in the options field of the
+ watchdog's info structure).
* get_timeleft: this routines returns the time that's left before a reset.
* ref: the operation that calls kref_get on the kref of a dynamically
allocated watchdog_device struct.
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 6aaefba..f4a02e5 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -218,6 +218,37 @@ out_timeout:
}
/*
+ * watchdog_set_pretimeout: set the watchdog timer pretimeout
+ * @wddev: the watchdog device to set the timeout for
+ * @timeout: pretimeout to set in seconds
+ */
+
+static int watchdog_set_pretimeout(struct watchdog_device *wddev,
+ unsigned int timeout)
+{
+ int err;
+
+ if (!wddev->ops->set_pretimeout ||
+ !(wddev->info->options & WDIOF_PRETIMEOUT))
+ return -EOPNOTSUPP;
+ if (watchdog_pretimeout_invalid(wddev, timeout))
+ return -EINVAL;
+
+ mutex_lock(&wddev->lock);
+
+ if (test_bit(WDOG_UNREGISTERED, &wddev->status)) {
+ err = -ENODEV;
+ goto out_timeout;
+ }
+
+ err = wddev->ops->set_pretimeout(wddev, timeout);
+
+out_timeout:
+ mutex_unlock(&wddev->lock);
+ return err;
+}
+
+/*
* watchdog_get_timeleft: wrapper to get the time left before a reboot
* @wddev: the watchdog device to get the remaining time from
* @timeleft: the time that's left
@@ -393,6 +424,12 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd,
if (err)
return err;
return put_user(val, p);
+ case WDIOC_SETPRETIMEOUT:
+ if (get_user(val, p))
+ return -EFAULT;
+ return watchdog_set_pretimeout(wdd, val);
+ case WDIOC_GETPRETIMEOUT:
+ return put_user(wdd->pretimeout, p);
default:
return -ENOTTY;
}
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index d74a0e9..281b949 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -25,6 +25,7 @@ struct watchdog_device;
* @ping: The routine that sends a keepalive ping to the watchdog device.
* @status: The routine that shows the status of the watchdog device.
* @set_timeout:The routine for setting the watchdog devices timeout value.
+ * @set_pretimeout:The routine for setting the watchdog devices pretimeout.
* @get_timeleft:The routine that get's the time that's left before a reset.
* @ref: The ref operation for dyn. allocated watchdog_device structs
* @unref: The unref operation for dyn. allocated watchdog_device structs
@@ -44,6 +45,7 @@ struct watchdog_ops {
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
+ int (*set_pretimeout)(struct watchdog_device *, unsigned int);
unsigned int (*get_timeleft)(struct watchdog_device *);
void (*ref)(struct watchdog_device *);
void (*unref)(struct watchdog_device *);
@@ -60,6 +62,7 @@ struct watchdog_ops {
* @ops: Pointer to the list of watchdog operations.
* @bootstatus: Status of the watchdog device at boot.
* @timeout: The watchdog devices timeout value.
+ * @pretimeout: The watchdog devices pre_timeout value.
* @min_timeout:The watchdog devices minimum timeout value.
* @max_timeout:The watchdog devices maximum timeout value.
* @driver-data:Pointer to the drivers private data.
@@ -86,6 +89,7 @@ struct watchdog_device {
const struct watchdog_ops *ops;
unsigned int bootstatus;
unsigned int timeout;
+ unsigned int pretimeout;
unsigned int min_timeout;
unsigned int max_timeout;
void *driver_data;
@@ -123,6 +127,13 @@ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigne
(t < wdd->min_timeout || t > wdd->max_timeout));
}
+/* Use the following function to check if a pretimeout value is invalid */
+static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd,
+ unsigned int t)
+{
+ return wdd->timeout && t >= wdd->timeout;
+}
+
/* Use the following functions to manipulate watchdog driver specific data */
static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data)
{
--
1.9.1
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