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authorLinus Torvalds <torvalds@linux-foundation.org>2011-07-29 23:28:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-29 23:28:47 -0700
commit2313bcdcc9ff1e42f51b200dc65ddaae14c347f4 (patch)
treefdb0e3f953841cdd661e36c40a965c9e044d82f5 /drivers/watchdog/watchdog_core.c
parent59ed2bb27492f74ab898ee1e26c69dfd78444640 (diff)
parent3f43f68e29f1dcb853d70280c7412fc0ef9a0da6 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-watchdog
* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-watchdog: (25 commits) watchdog: WatchDog Timer Driver Core - Add minimum and max timeout watchdog: WatchDog Timer Driver Core - Add ioctl call watchdog: WatchDog Timer Driver Core - Add nowayout feature watchdog: WatchDog Timer Driver Core - Add Magic Close feature watchdog: WatchDog Timer Driver Core - Add WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT ioctl watchdog: WatchDog Timer Driver Core - Add WDIOC_SETOPTIONS ioctl watchdog: WatchDog Timer Driver Core - Add WDIOC_KEEPALIVE ioctl watchdog: WatchDog Timer Driver Core - Add basic ioctl functionality watchdog: WatchDog Timer Driver Core - Add basic framework watchdog: hpwdt: add next gen HP servers watchdog: it8712f_wdt.c: improve includes watchdog: at91sam9/wdt: move register header to drivers watchdog: Add Xilinx watchdog timer driver watchdog: remove empty pm-functions watchdog: sp805: Flush posted writes in enable/disable. watchdog: sp805: Don't write 0 to the load value register. watchdog: imx2_wdt: add device tree probe support watchdog: s3c2410: Add support for device tree based probe watchdog: mpcore_wdt: Add suspend/resume support. watchdog: mtx1-wdt: use dev_{err,info} instead of printk() ...
Diffstat (limited to 'drivers/watchdog/watchdog_core.c')
-rw-r--r--drivers/watchdog/watchdog_core.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
new file mode 100644
index 000000000000..cfa1a1518aad
--- /dev/null
+++ b/drivers/watchdog/watchdog_core.c
@@ -0,0 +1,111 @@
+/*
+ * watchdog_core.c
+ *
+ * (c) Copyright 2008-2011 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * All Rights Reserved.
+ *
+ * (c) Copyright 2008-2011 Wim Van Sebroeck <wim@iguana.be>.
+ *
+ * This source code is part of the generic code that can be used
+ * by all the watchdog timer drivers.
+ *
+ * Based on source code of the following authors:
+ * Matt Domsch <Matt_Domsch@dell.com>,
+ * Rob Radez <rob@osinvestor.com>,
+ * Rusty Lynch <rusty@linux.co.intel.com>
+ * Satyam Sharma <satyam@infradead.org>
+ * Randy Dunlap <randy.dunlap@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw.
+ * admit liability nor provide warranty for any of this software.
+ * This material is provided "AS-IS" and at no charge.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h> /* For EXPORT_SYMBOL/module stuff/... */
+#include <linux/types.h> /* For standard types */
+#include <linux/errno.h> /* For the -ENODEV/... values */
+#include <linux/kernel.h> /* For printk/panic/... */
+#include <linux/watchdog.h> /* For watchdog specific items */
+#include <linux/init.h> /* For __init/__exit/... */
+
+#include "watchdog_dev.h" /* For watchdog_dev_register/... */
+
+/**
+ * watchdog_register_device() - register a watchdog device
+ * @wdd: watchdog device
+ *
+ * Register a watchdog device with the kernel so that the
+ * watchdog timer can be accessed from userspace.
+ *
+ * A zero is returned on success and a negative errno code for
+ * failure.
+ */
+int watchdog_register_device(struct watchdog_device *wdd)
+{
+ int ret;
+
+ if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL)
+ return -EINVAL;
+
+ /* Mandatory operations need to be supported */
+ if (wdd->ops->start == NULL || wdd->ops->stop == NULL)
+ return -EINVAL;
+
+ /*
+ * Check that we have valid min and max timeout values, if
+ * not reset them both to 0 (=not used or unknown)
+ */
+ if (wdd->min_timeout > wdd->max_timeout) {
+ pr_info("Invalid min and max timeout values, resetting to 0!\n");
+ wdd->min_timeout = 0;
+ wdd->max_timeout = 0;
+ }
+
+ /*
+ * Note: now that all watchdog_device data has been verified, we
+ * will not check this anymore in other functions. If data gets
+ * corrupted in a later stage then we expect a kernel panic!
+ */
+
+ /* We only support 1 watchdog device via the /dev/watchdog interface */
+ ret = watchdog_dev_register(wdd);
+ if (ret) {
+ pr_err("error registering /dev/watchdog (err=%d).\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(watchdog_register_device);
+
+/**
+ * watchdog_unregister_device() - unregister a watchdog device
+ * @wdd: watchdog device to unregister
+ *
+ * Unregister a watchdog device that was previously successfully
+ * registered with watchdog_register_device().
+ */
+void watchdog_unregister_device(struct watchdog_device *wdd)
+{
+ int ret;
+
+ if (wdd == NULL)
+ return;
+
+ ret = watchdog_dev_unregister(wdd);
+ if (ret)
+ pr_err("error unregistering /dev/watchdog (err=%d).\n", ret);
+}
+EXPORT_SYMBOL_GPL(watchdog_unregister_device);
+
+MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
+MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
+MODULE_DESCRIPTION("WatchDog Timer Driver Core");
+MODULE_LICENSE("GPL");