Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * ICP Wafer 5823 Single Board Computer WDT driver |
| 3 | * http://www.icpamerica.com/wafer_5823.php |
| 4 | * May also work on other similar models |
| 5 | * |
| 6 | * (c) Copyright 2002 Justin Cormack <justin@street-vision.com> |
| 7 | * |
| 8 | * Release 0.02 |
| 9 | * |
| 10 | * Based on advantechwdt.c which is based on wdt.c. |
| 11 | * Original copyright messages: |
| 12 | * |
| 13 | * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved. |
| 14 | * http://www.redhat.com |
| 15 | * |
| 16 | * This program is free software; you can redistribute it and/or |
| 17 | * modify it under the terms of the GNU General Public License |
| 18 | * as published by the Free Software Foundation; either version |
| 19 | * 2 of the License, or (at your option) any later version. |
| 20 | * |
| 21 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide |
| 22 | * warranty for any of this software. This material is provided |
| 23 | * "AS-IS" and at no charge. |
| 24 | * |
| 25 | * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> |
| 26 | * |
| 27 | */ |
| 28 | |
| 29 | #include <linux/module.h> |
| 30 | #include <linux/moduleparam.h> |
| 31 | #include <linux/miscdevice.h> |
| 32 | #include <linux/watchdog.h> |
| 33 | #include <linux/fs.h> |
| 34 | #include <linux/ioport.h> |
| 35 | #include <linux/notifier.h> |
| 36 | #include <linux/reboot.h> |
| 37 | #include <linux/init.h> |
| 38 | #include <linux/spinlock.h> |
| 39 | #include <asm/io.h> |
| 40 | #include <asm/uaccess.h> |
| 41 | |
| 42 | #define WATCHDOG_NAME "Wafer 5823 WDT" |
| 43 | #define PFX WATCHDOG_NAME ": " |
| 44 | #define WD_TIMO 60 /* 60 sec default timeout */ |
| 45 | |
| 46 | static unsigned long wafwdt_is_open; |
| 47 | static char expect_close; |
| 48 | static spinlock_t wafwdt_lock; |
| 49 | |
| 50 | /* |
| 51 | * You must set these - there is no sane way to probe for this board. |
| 52 | * |
| 53 | * To enable, write the timeout value in seconds (1 to 255) to I/O |
| 54 | * port WDT_START, then read the port to start the watchdog. To pat |
| 55 | * the dog, read port WDT_STOP to stop the timer, then read WDT_START |
| 56 | * to restart it again. |
| 57 | */ |
| 58 | |
| 59 | static int wdt_stop = 0x843; |
| 60 | static int wdt_start = 0x443; |
| 61 | |
| 62 | static int timeout = WD_TIMO; /* in seconds */ |
| 63 | module_param(timeout, int, 0); |
| 64 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WD_TIMO) "."); |
| 65 | |
Andrey Panin | 4bfdf37 | 2005-07-27 11:43:58 -0700 | [diff] [blame] | 66 | static int nowayout = WATCHDOG_NOWAYOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | module_param(nowayout, int, 0); |
| 68 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); |
| 69 | |
| 70 | static void wafwdt_ping(void) |
| 71 | { |
| 72 | /* pat watchdog */ |
| 73 | spin_lock(&wafwdt_lock); |
| 74 | inb_p(wdt_stop); |
| 75 | inb_p(wdt_start); |
| 76 | spin_unlock(&wafwdt_lock); |
| 77 | } |
| 78 | |
| 79 | static void wafwdt_start(void) |
| 80 | { |
| 81 | /* start up watchdog */ |
| 82 | outb_p(timeout, wdt_start); |
| 83 | inb_p(wdt_start); |
| 84 | } |
| 85 | |
| 86 | static void |
| 87 | wafwdt_stop(void) |
| 88 | { |
| 89 | /* stop watchdog */ |
| 90 | inb_p(wdt_stop); |
| 91 | } |
| 92 | |
| 93 | static ssize_t wafwdt_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos) |
| 94 | { |
| 95 | /* See if we got the magic character 'V' and reload the timer */ |
| 96 | if (count) { |
| 97 | if (!nowayout) { |
| 98 | size_t i; |
| 99 | |
| 100 | /* In case it was set long ago */ |
| 101 | expect_close = 0; |
| 102 | |
| 103 | /* scan to see whether or not we got the magic character */ |
| 104 | for (i = 0; i != count; i++) { |
| 105 | char c; |
| 106 | if (get_user(c, buf + i)) |
| 107 | return -EFAULT; |
| 108 | if (c == 'V') |
| 109 | expect_close = 42; |
| 110 | } |
| 111 | } |
| 112 | /* Well, anyhow someone wrote to us, we should return that favour */ |
| 113 | wafwdt_ping(); |
| 114 | } |
| 115 | return count; |
| 116 | } |
| 117 | |
| 118 | static int wafwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, |
| 119 | unsigned long arg) |
| 120 | { |
| 121 | int new_timeout; |
| 122 | void __user *argp = (void __user *)arg; |
| 123 | int __user *p = argp; |
| 124 | static struct watchdog_info ident = { |
| 125 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, |
| 126 | .firmware_version = 1, |
| 127 | .identity = "Wafer 5823 WDT", |
| 128 | }; |
| 129 | |
| 130 | switch (cmd) { |
| 131 | case WDIOC_GETSUPPORT: |
| 132 | if (copy_to_user(argp, &ident, sizeof (ident))) |
| 133 | return -EFAULT; |
| 134 | break; |
| 135 | |
| 136 | case WDIOC_GETSTATUS: |
| 137 | case WDIOC_GETBOOTSTATUS: |
| 138 | return put_user(0, p); |
| 139 | |
| 140 | case WDIOC_KEEPALIVE: |
| 141 | wafwdt_ping(); |
| 142 | break; |
| 143 | |
| 144 | case WDIOC_SETTIMEOUT: |
| 145 | if (get_user(new_timeout, p)) |
| 146 | return -EFAULT; |
| 147 | if ((new_timeout < 1) || (new_timeout > 255)) |
| 148 | return -EINVAL; |
| 149 | timeout = new_timeout; |
| 150 | wafwdt_stop(); |
| 151 | wafwdt_start(); |
| 152 | /* Fall */ |
| 153 | case WDIOC_GETTIMEOUT: |
| 154 | return put_user(timeout, p); |
| 155 | |
| 156 | case WDIOC_SETOPTIONS: |
| 157 | { |
| 158 | int options, retval = -EINVAL; |
| 159 | |
| 160 | if (get_user(options, p)) |
| 161 | return -EFAULT; |
| 162 | |
| 163 | if (options & WDIOS_DISABLECARD) { |
| 164 | wafwdt_start(); |
| 165 | retval = 0; |
| 166 | } |
| 167 | |
| 168 | if (options & WDIOS_ENABLECARD) { |
| 169 | wafwdt_stop(); |
| 170 | retval = 0; |
| 171 | } |
| 172 | |
| 173 | return retval; |
| 174 | } |
| 175 | |
| 176 | default: |
Samuel Tardieu | 795b89d | 2006-09-09 17:34:31 +0200 | [diff] [blame] | 177 | return -ENOTTY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | } |
| 179 | return 0; |
| 180 | } |
| 181 | |
| 182 | static int wafwdt_open(struct inode *inode, struct file *file) |
| 183 | { |
| 184 | if (test_and_set_bit(0, &wafwdt_is_open)) |
| 185 | return -EBUSY; |
| 186 | |
| 187 | /* |
| 188 | * Activate |
| 189 | */ |
| 190 | wafwdt_start(); |
| 191 | return nonseekable_open(inode, file); |
| 192 | } |
| 193 | |
| 194 | static int |
| 195 | wafwdt_close(struct inode *inode, struct file *file) |
| 196 | { |
| 197 | if (expect_close == 42) { |
| 198 | wafwdt_stop(); |
| 199 | } else { |
| 200 | printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); |
| 201 | wafwdt_ping(); |
| 202 | } |
| 203 | clear_bit(0, &wafwdt_is_open); |
| 204 | expect_close = 0; |
| 205 | return 0; |
| 206 | } |
| 207 | |
| 208 | /* |
| 209 | * Notifier for system down |
| 210 | */ |
| 211 | |
| 212 | static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) |
| 213 | { |
| 214 | if (code == SYS_DOWN || code == SYS_HALT) { |
| 215 | /* Turn the WDT off */ |
| 216 | wafwdt_stop(); |
| 217 | } |
| 218 | return NOTIFY_DONE; |
| 219 | } |
| 220 | |
| 221 | /* |
| 222 | * Kernel Interfaces |
| 223 | */ |
| 224 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 225 | static const struct file_operations wafwdt_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | .owner = THIS_MODULE, |
| 227 | .llseek = no_llseek, |
| 228 | .write = wafwdt_write, |
| 229 | .ioctl = wafwdt_ioctl, |
| 230 | .open = wafwdt_open, |
| 231 | .release = wafwdt_close, |
| 232 | }; |
| 233 | |
| 234 | static struct miscdevice wafwdt_miscdev = { |
| 235 | .minor = WATCHDOG_MINOR, |
| 236 | .name = "watchdog", |
| 237 | .fops = &wafwdt_fops, |
| 238 | }; |
| 239 | |
| 240 | /* |
| 241 | * The WDT needs to learn about soft shutdowns in order to |
| 242 | * turn the timebomb registers off. |
| 243 | */ |
| 244 | |
| 245 | static struct notifier_block wafwdt_notifier = { |
| 246 | .notifier_call = wafwdt_notify_sys, |
| 247 | }; |
| 248 | |
| 249 | static int __init wafwdt_init(void) |
| 250 | { |
| 251 | int ret; |
| 252 | |
| 253 | printk(KERN_INFO "WDT driver for Wafer 5823 single board computer initialising.\n"); |
| 254 | |
| 255 | spin_lock_init(&wafwdt_lock); |
| 256 | |
| 257 | if (timeout < 1 || timeout > 255) { |
| 258 | timeout = WD_TIMO; |
| 259 | printk (KERN_INFO PFX "timeout value must be 1<=x<=255, using %d\n", |
| 260 | timeout); |
| 261 | } |
| 262 | |
| 263 | if (wdt_stop != wdt_start) { |
| 264 | if(!request_region(wdt_stop, 1, "Wafer 5823 WDT")) { |
| 265 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| 266 | wdt_stop); |
| 267 | ret = -EIO; |
| 268 | goto error; |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | if(!request_region(wdt_start, 1, "Wafer 5823 WDT")) { |
| 273 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| 274 | wdt_start); |
| 275 | ret = -EIO; |
| 276 | goto error2; |
| 277 | } |
| 278 | |
| 279 | ret = register_reboot_notifier(&wafwdt_notifier); |
| 280 | if (ret != 0) { |
| 281 | printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", |
| 282 | ret); |
| 283 | goto error3; |
| 284 | } |
| 285 | |
| 286 | ret = misc_register(&wafwdt_miscdev); |
| 287 | if (ret != 0) { |
| 288 | printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", |
| 289 | WATCHDOG_MINOR, ret); |
| 290 | goto error4; |
| 291 | } |
| 292 | |
| 293 | printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", |
| 294 | timeout, nowayout); |
| 295 | |
| 296 | return ret; |
| 297 | error4: |
| 298 | unregister_reboot_notifier(&wafwdt_notifier); |
| 299 | error3: |
| 300 | release_region(wdt_start, 1); |
| 301 | error2: |
| 302 | if (wdt_stop != wdt_start) |
| 303 | release_region(wdt_stop, 1); |
| 304 | error: |
| 305 | return ret; |
| 306 | } |
| 307 | |
| 308 | static void __exit wafwdt_exit(void) |
| 309 | { |
| 310 | misc_deregister(&wafwdt_miscdev); |
| 311 | unregister_reboot_notifier(&wafwdt_notifier); |
| 312 | if(wdt_stop != wdt_start) |
| 313 | release_region(wdt_stop, 1); |
| 314 | release_region(wdt_start, 1); |
| 315 | } |
| 316 | |
| 317 | module_init(wafwdt_init); |
| 318 | module_exit(wafwdt_exit); |
| 319 | |
| 320 | MODULE_AUTHOR("Justin Cormack"); |
| 321 | MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver"); |
| 322 | MODULE_LICENSE("GPL"); |
| 323 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
| 324 | |
| 325 | /* end of wafer5823wdt.c */ |