Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * IndyDog 0.3 A Hardware Watchdog Device for SGI IP22 |
| 3 | * |
| 4 | * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * based on softdog.c by Alan Cox <alan@redhat.com> |
| 12 | */ |
| 13 | |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/moduleparam.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/types.h> |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/fs.h> |
| 19 | #include <linux/mm.h> |
| 20 | #include <linux/miscdevice.h> |
| 21 | #include <linux/watchdog.h> |
| 22 | #include <linux/notifier.h> |
| 23 | #include <linux/reboot.h> |
| 24 | #include <linux/init.h> |
| 25 | #include <asm/uaccess.h> |
| 26 | #include <asm/sgi/mc.h> |
| 27 | |
| 28 | #define PFX "indydog: " |
| 29 | static int indydog_alive; |
| 30 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ |
| 32 | |
Andrey Panin | 4bfdf37 | 2005-07-27 11:43:58 -0700 | [diff] [blame] | 33 | static int nowayout = WATCHDOG_NOWAYOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | module_param(nowayout, int, 0); |
| 35 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); |
| 36 | |
| 37 | static void indydog_start(void) |
| 38 | { |
| 39 | u32 mc_ctrl0 = sgimc->cpuctrl0; |
| 40 | |
| 41 | mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG; |
| 42 | sgimc->cpuctrl0 = mc_ctrl0; |
| 43 | } |
| 44 | |
| 45 | static void indydog_stop(void) |
| 46 | { |
| 47 | u32 mc_ctrl0 = sgimc->cpuctrl0; |
| 48 | |
| 49 | mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG; |
| 50 | sgimc->cpuctrl0 = mc_ctrl0; |
| 51 | |
| 52 | printk(KERN_INFO PFX "Stopped watchdog timer.\n"); |
| 53 | } |
| 54 | |
| 55 | static void indydog_ping(void) |
| 56 | { |
| 57 | sgimc->watchdogt = 0; |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * Allow only one person to hold it open |
| 62 | */ |
| 63 | static int indydog_open(struct inode *inode, struct file *file) |
| 64 | { |
| 65 | if (indydog_alive) |
| 66 | return -EBUSY; |
| 67 | |
| 68 | if (nowayout) |
| 69 | __module_get(THIS_MODULE); |
| 70 | |
| 71 | /* Activate timer */ |
| 72 | indydog_start(); |
| 73 | indydog_ping(); |
| 74 | |
| 75 | indydog_alive = 1; |
| 76 | printk(KERN_INFO "Started watchdog timer.\n"); |
| 77 | |
| 78 | return nonseekable_open(inode, file); |
| 79 | } |
| 80 | |
| 81 | static int indydog_release(struct inode *inode, struct file *file) |
| 82 | { |
| 83 | /* Shut off the timer. |
| 84 | * Lock it in if it's a module and we defined ...NOWAYOUT */ |
| 85 | if (!nowayout) |
| 86 | indydog_stop(); /* Turn the WDT off */ |
| 87 | |
| 88 | indydog_alive = 0; |
| 89 | |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | static ssize_t indydog_write(struct file *file, const char *data, size_t len, loff_t *ppos) |
| 94 | { |
| 95 | /* Refresh the timer. */ |
| 96 | if (len) { |
| 97 | indydog_ping(); |
| 98 | } |
| 99 | return len; |
| 100 | } |
| 101 | |
| 102 | static int indydog_ioctl(struct inode *inode, struct file *file, |
| 103 | unsigned int cmd, unsigned long arg) |
| 104 | { |
| 105 | int options, retval = -EINVAL; |
| 106 | static struct watchdog_info ident = { |
| 107 | .options = WDIOF_KEEPALIVEPING | |
| 108 | WDIOF_MAGICCLOSE, |
| 109 | .firmware_version = 0, |
| 110 | .identity = "Hardware Watchdog for SGI IP22", |
| 111 | }; |
| 112 | |
| 113 | switch (cmd) { |
| 114 | default: |
Samuel Tardieu | 795b89d | 2006-09-09 17:34:31 +0200 | [diff] [blame] | 115 | return -ENOTTY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | case WDIOC_GETSUPPORT: |
| 117 | if (copy_to_user((struct watchdog_info *)arg, |
| 118 | &ident, sizeof(ident))) |
| 119 | return -EFAULT; |
| 120 | return 0; |
| 121 | case WDIOC_GETSTATUS: |
| 122 | case WDIOC_GETBOOTSTATUS: |
| 123 | return put_user(0,(int *)arg); |
| 124 | case WDIOC_KEEPALIVE: |
| 125 | indydog_ping(); |
| 126 | return 0; |
| 127 | case WDIOC_GETTIMEOUT: |
| 128 | return put_user(WATCHDOG_TIMEOUT,(int *)arg); |
| 129 | case WDIOC_SETOPTIONS: |
| 130 | { |
| 131 | if (get_user(options, (int *)arg)) |
| 132 | return -EFAULT; |
| 133 | |
| 134 | if (options & WDIOS_DISABLECARD) { |
| 135 | indydog_stop(); |
| 136 | retval = 0; |
| 137 | } |
| 138 | |
| 139 | if (options & WDIOS_ENABLECARD) { |
| 140 | indydog_start(); |
| 141 | retval = 0; |
| 142 | } |
| 143 | |
| 144 | return retval; |
| 145 | } |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | static int indydog_notify_sys(struct notifier_block *this, unsigned long code, void *unused) |
| 150 | { |
| 151 | if (code == SYS_DOWN || code == SYS_HALT) |
| 152 | indydog_stop(); /* Turn the WDT off */ |
| 153 | |
| 154 | return NOTIFY_DONE; |
| 155 | } |
| 156 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 157 | static const struct file_operations indydog_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | .owner = THIS_MODULE, |
| 159 | .llseek = no_llseek, |
| 160 | .write = indydog_write, |
| 161 | .ioctl = indydog_ioctl, |
| 162 | .open = indydog_open, |
| 163 | .release = indydog_release, |
| 164 | }; |
| 165 | |
| 166 | static struct miscdevice indydog_miscdev = { |
| 167 | .minor = WATCHDOG_MINOR, |
| 168 | .name = "watchdog", |
| 169 | .fops = &indydog_fops, |
| 170 | }; |
| 171 | |
| 172 | static struct notifier_block indydog_notifier = { |
| 173 | .notifier_call = indydog_notify_sys, |
| 174 | }; |
| 175 | |
| 176 | static char banner[] __initdata = |
| 177 | KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n"; |
| 178 | |
| 179 | static int __init watchdog_init(void) |
| 180 | { |
| 181 | int ret; |
| 182 | |
| 183 | ret = register_reboot_notifier(&indydog_notifier); |
| 184 | if (ret) { |
| 185 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", |
| 186 | ret); |
| 187 | return ret; |
| 188 | } |
| 189 | |
| 190 | ret = misc_register(&indydog_miscdev); |
| 191 | if (ret) { |
| 192 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", |
| 193 | WATCHDOG_MINOR, ret); |
| 194 | unregister_reboot_notifier(&indydog_notifier); |
| 195 | return ret; |
| 196 | } |
| 197 | |
| 198 | printk(banner); |
| 199 | |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | static void __exit watchdog_exit(void) |
| 204 | { |
| 205 | misc_deregister(&indydog_miscdev); |
| 206 | unregister_reboot_notifier(&indydog_notifier); |
| 207 | } |
| 208 | |
| 209 | module_init(watchdog_init); |
| 210 | module_exit(watchdog_exit); |
| 211 | |
| 212 | MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>"); |
| 213 | MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22"); |
| 214 | MODULE_LICENSE("GPL"); |
| 215 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |