Initial import

1 files changed, 226 insertions, 0 deletions

diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
new file mode 100644
index 000000000..cec9b5596
--- /dev/null
+++ b/drivers/watchdog/watchdog_core.c
@@ -0,0 +1,226 @@
+/*
+ *	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 <linux/idr.h>		/* For ida_* macros */
+#include <linux/err.h>		/* For IS_ERR macros */
+#include <linux/of.h>		/* For of_get_timeout_sec */
+
+#include "watchdog_core.h"	/* For watchdog_dev_register/... */
+
+static DEFINE_IDA(watchdog_ida);
+static struct class *watchdog_class;
+
+static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
+{
+	/*
+	 * 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;
+	}
+}
+
+/**
+ * watchdog_init_timeout() - initialize the timeout field
+ * @timeout_parm: timeout module parameter
+ * @dev: Device that stores the timeout-sec property
+ *
+ * Initialize the timeout field of the watchdog_device struct with either the
+ * timeout module parameter (if it is valid value) or the timeout-sec property
+ * (only if it is a valid value and the timeout_parm is out of bounds).
+ * If none of them are valid then we keep the old value (which should normally
+ * be the default timeout value.
+ *
+ * A zero is returned on success and -EINVAL for failure.
+ */
+int watchdog_init_timeout(struct watchdog_device *wdd,
+				unsigned int timeout_parm, struct device *dev)
+{
+	unsigned int t = 0;
+	int ret = 0;
+
+	watchdog_check_min_max_timeout(wdd);
+
+	/* try to get the timeout module parameter first */
+	if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) {
+		wdd->timeout = timeout_parm;
+		return ret;
+	}
+	if (timeout_parm)
+		ret = -EINVAL;
+
+	/* try to get the timeout_sec property */
+	if (dev == NULL || dev->of_node == NULL)
+		return ret;
+	of_property_read_u32(dev->of_node, "timeout-sec", &t);
+	if (!watchdog_timeout_invalid(wdd, t) && t)
+		wdd->timeout = t;
+	else
+		ret = -EINVAL;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(watchdog_init_timeout);
+
+/**
+ * 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, id, devno;
+
+	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;
+
+	watchdog_check_min_max_timeout(wdd);
+
+	/*
+	 * 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!
+	 */
+
+	mutex_init(&wdd->lock);
+	id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL);
+	if (id < 0)
+		return id;
+	wdd->id = id;
+
+	ret = watchdog_dev_register(wdd);
+	if (ret) {
+		ida_simple_remove(&watchdog_ida, id);
+		if (!(id == 0 && ret == -EBUSY))
+			return ret;
+
+		/* Retry in case a legacy watchdog module exists */
+		id = ida_simple_get(&watchdog_ida, 1, MAX_DOGS, GFP_KERNEL);
+		if (id < 0)
+			return id;
+		wdd->id = id;
+
+		ret = watchdog_dev_register(wdd);
+		if (ret) {
+			ida_simple_remove(&watchdog_ida, id);
+			return ret;
+		}
+	}
+
+	devno = wdd->cdev.dev;
+	wdd->dev = device_create(watchdog_class, wdd->parent, devno,
+					NULL, "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;
+	}
+
+	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;
+	int devno;
+
+	if (wdd == NULL)
+		return;
+
+	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);
+	ida_simple_remove(&watchdog_ida, wdd->id);
+	wdd->dev = NULL;
+}
+EXPORT_SYMBOL_GPL(watchdog_unregister_device);
+
+static int __init watchdog_init(void)
+{
+	int err;
+
+	watchdog_class = class_create(THIS_MODULE, "watchdog");
+	if (IS_ERR(watchdog_class)) {
+		pr_err("couldn't create class\n");
+		return PTR_ERR(watchdog_class);
+	}
+
+	err = watchdog_dev_init();
+	if (err < 0) {
+		class_destroy(watchdog_class);
+		return err;
+	}
+
+	return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+	watchdog_dev_exit();
+	class_destroy(watchdog_class);
+	ida_destroy(&watchdog_ida);
+}
+
+subsys_initcall(watchdog_init);
+module_exit(watchdog_exit);
+
+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");