projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 43316044 WVS |
1 | /* |
| 2 | * watchdog_core.c | |
| 3 | * | |
| 4 | * (c) Copyright 2008-2011 Alan Cox <alan@lxorguk.ukuu.org.uk>, | |
| 5 | * All Rights Reserved. | |
| 6 | * | |
| 7 | * (c) Copyright 2008-2011 Wim Van Sebroeck <wim@iguana.be>. | |
| 8 | * | |
| 9 | * This source code is part of the generic code that can be used | |
| 10 | * by all the watchdog timer drivers. | |
| 11 | * | |
| 12 | * Based on source code of the following authors: | |
| 13 | * Matt Domsch <Matt_Domsch@dell.com>, | |
| 14 | * Rob Radez <rob@osinvestor.com>, | |
| 15 | * Rusty Lynch <rusty@linux.co.intel.com> | |
| 16 | * Satyam Sharma <satyam@infradead.org> | |
| 17 | * Randy Dunlap <randy.dunlap@oracle.com> | |
| 18 | * | |
| 19 | * This program is free software; you can redistribute it and/or | |
| 20 | * modify it under the terms of the GNU General Public License | |
| 21 | * as published by the Free Software Foundation; either version | |
| 22 | * 2 of the License, or (at your option) any later version. | |
| 23 | * | |
| 24 | * Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw. | |
| 25 | * admit liability nor provide warranty for any of this software. | |
| 26 | * This material is provided "AS-IS" and at no charge. | |
| 27 | */ | |
| 28 | ||
| 29 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
| 30 | ||
| 31 | #include <linux/module.h> /* For EXPORT_SYMBOL/module stuff/... */ | |
| 32 | #include <linux/types.h> /* For standard types */ | |
| 33 | #include <linux/errno.h> /* For the -ENODEV/... values */ | |
| 34 | #include <linux/kernel.h> /* For printk/panic/... */ | |
| 35 | #include <linux/watchdog.h> /* For watchdog specific items */ | |
| 36 | #include <linux/init.h> /* For __init/__exit/... */ | |
| 37 | ||
| 38 | #include "watchdog_dev.h" /* For watchdog_dev_register/... */ | |
| 39 | ||
| 40 | /** | |
| 41 | * watchdog_register_device() - register a watchdog device | |
| 42 | * @wdd: watchdog device | |
| 43 | * | |
| 44 | * Register a watchdog device with the kernel so that the | |
| 45 | * watchdog timer can be accessed from userspace. | |
| 46 | * | |
| 47 | * A zero is returned on success and a negative errno code for | |
| 48 | * failure. | |
| 49 | */ | |
| 50 | int watchdog_register_device(struct watchdog_device *wdd) | |
| 51 | { | |
| 52 | int ret; | |
| 53 | ||
| 54 | if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL) | |
| 55 | return -EINVAL; | |
| 56 | ||
| 57 | /* Mandatory operations need to be supported */ | |
| 58 | if (wdd->ops->start == NULL || wdd->ops->stop == NULL) | |
| 59 | return -EINVAL; | |
| 60 | ||
| 61 | /* | |
| 62 | * Note: now that all watchdog_device data has been verified, we | |
| 63 | * will not check this anymore in other functions. If data gets | |
| 64 | * corrupted in a later stage then we expect a kernel panic! | |
| 65 | */ | |
| 66 | ||
| 67 | /* We only support 1 watchdog device via the /dev/watchdog interface */ | |
| 68 | ret = watchdog_dev_register(wdd); | |
| 69 | if (ret) { | |
| 70 | pr_err("error registering /dev/watchdog (err=%d).\n", ret); | |
| 71 | return ret; | |
| 72 | } | |
| 73 | ||
| 74 | return 0; | |
| 75 | } | |
| 76 | EXPORT_SYMBOL_GPL(watchdog_register_device); | |
| 77 | ||
| 78 | /** | |
| 79 | * watchdog_unregister_device() - unregister a watchdog device | |
| 80 | * @wdd: watchdog device to unregister | |
| 81 | * | |
| 82 | * Unregister a watchdog device that was previously successfully | |
| 83 | * registered with watchdog_register_device(). | |
| 84 | */ | |
| 85 | void watchdog_unregister_device(struct watchdog_device *wdd) | |
| 86 | { | |
| 87 | int ret; | |
| 88 | ||
| 89 | if (wdd == NULL) | |
| 90 | return; | |
| 91 | ||
| 92 | ret = watchdog_dev_unregister(wdd); | |
| 93 | if (ret) | |
| 94 | pr_err("error unregistering /dev/watchdog (err=%d).\n", ret); | |
| 95 | } | |
| 96 | EXPORT_SYMBOL_GPL(watchdog_unregister_device); | |
| 97 | ||
| 98 | MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>"); | |
| 99 | MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>"); | |
| 100 | MODULE_DESCRIPTION("WatchDog Timer Driver Core"); | |
| 101 | MODULE_LICENSE("GPL"); |