Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Advantech Single Board Computer WDT driver |
| 3 | * |
| 4 | * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> |
| 5 | * |
| 6 | * Based on acquirewdt.c which is based on wdt.c. |
| 7 | * Original copyright messages: |
| 8 | * |
| 9 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. |
| 10 | * http://www.redhat.com |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or |
| 13 | * modify it under the terms of the GNU General Public License |
| 14 | * as published by the Free Software Foundation; either version |
| 15 | * 2 of the License, or (at your option) any later version. |
| 16 | * |
| 17 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide |
| 18 | * warranty for any of this software. This material is provided |
| 19 | * "AS-IS" and at no charge. |
| 20 | * |
| 21 | * (c) Copyright 1995 Alan Cox <alan@redhat.com> |
| 22 | * |
| 23 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> |
| 24 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT |
| 25 | * |
| 26 | * 16-Oct-2002 Rob Radez <rob@osinvestor.com> |
| 27 | * Clean up ioctls, clean up init + exit, add expect close support, |
| 28 | * add wdt_start and wdt_stop as parameters. |
| 29 | */ |
| 30 | |
| 31 | #include <linux/module.h> |
| 32 | #include <linux/moduleparam.h> |
| 33 | #include <linux/types.h> |
| 34 | #include <linux/miscdevice.h> |
| 35 | #include <linux/watchdog.h> |
| 36 | #include <linux/fs.h> |
| 37 | #include <linux/ioport.h> |
| 38 | #include <linux/notifier.h> |
| 39 | #include <linux/reboot.h> |
| 40 | #include <linux/init.h> |
| 41 | |
| 42 | #include <asm/io.h> |
| 43 | #include <asm/uaccess.h> |
| 44 | #include <asm/system.h> |
| 45 | |
| 46 | #define WATCHDOG_NAME "Advantech WDT" |
| 47 | #define PFX WATCHDOG_NAME ": " |
| 48 | #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ |
| 49 | |
| 50 | static unsigned long advwdt_is_open; |
| 51 | static char adv_expect_close; |
| 52 | |
| 53 | /* |
| 54 | * You must set these - there is no sane way to probe for this board. |
| 55 | * |
| 56 | * To enable or restart, write the timeout value in seconds (1 to 63) |
| 57 | * to I/O port wdt_start. To disable, read I/O port wdt_stop. |
| 58 | * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but |
| 59 | * check your manual (at least the PCA-6159 seems to be different - |
| 60 | * the manual says wdt_stop is 0x43, not 0x443). |
| 61 | * (0x43 is also a write-only control register for the 8254 timer!) |
| 62 | */ |
| 63 | |
| 64 | static int wdt_stop = 0x443; |
| 65 | module_param(wdt_stop, int, 0); |
| 66 | MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)"); |
| 67 | |
| 68 | static int wdt_start = 0x443; |
| 69 | module_param(wdt_start, int, 0); |
| 70 | MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)"); |
| 71 | |
| 72 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ |
| 73 | module_param(timeout, int, 0); |
| 74 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) "."); |
| 75 | |
Andrey Panin | 4bfdf37 | 2005-07-27 11:43:58 -0700 | [diff] [blame^] | 76 | static int nowayout = WATCHDOG_NOWAYOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | module_param(nowayout, int, 0); |
| 78 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); |
| 79 | |
| 80 | /* |
| 81 | * Kernel methods. |
| 82 | */ |
| 83 | |
| 84 | static void |
| 85 | advwdt_ping(void) |
| 86 | { |
| 87 | /* Write a watchdog value */ |
| 88 | outb_p(timeout, wdt_start); |
| 89 | } |
| 90 | |
| 91 | static void |
| 92 | advwdt_disable(void) |
| 93 | { |
| 94 | inb_p(wdt_stop); |
| 95 | } |
| 96 | |
| 97 | static ssize_t |
| 98 | advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
| 99 | { |
| 100 | if (count) { |
| 101 | if (!nowayout) { |
| 102 | size_t i; |
| 103 | |
| 104 | adv_expect_close = 0; |
| 105 | |
| 106 | for (i = 0; i != count; i++) { |
| 107 | char c; |
| 108 | if (get_user(c, buf+i)) |
| 109 | return -EFAULT; |
| 110 | if (c == 'V') |
| 111 | adv_expect_close = 42; |
| 112 | } |
| 113 | } |
| 114 | advwdt_ping(); |
| 115 | } |
| 116 | return count; |
| 117 | } |
| 118 | |
| 119 | static int |
| 120 | advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, |
| 121 | unsigned long arg) |
| 122 | { |
| 123 | int new_timeout; |
| 124 | void __user *argp = (void __user *)arg; |
| 125 | int __user *p = argp; |
| 126 | static struct watchdog_info ident = { |
| 127 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, |
| 128 | .firmware_version = 1, |
| 129 | .identity = "Advantech WDT", |
| 130 | }; |
| 131 | |
| 132 | switch (cmd) { |
| 133 | case WDIOC_GETSUPPORT: |
| 134 | if (copy_to_user(argp, &ident, sizeof(ident))) |
| 135 | return -EFAULT; |
| 136 | break; |
| 137 | |
| 138 | case WDIOC_GETSTATUS: |
| 139 | case WDIOC_GETBOOTSTATUS: |
| 140 | return put_user(0, p); |
| 141 | |
| 142 | case WDIOC_KEEPALIVE: |
| 143 | advwdt_ping(); |
| 144 | break; |
| 145 | |
| 146 | case WDIOC_SETTIMEOUT: |
| 147 | if (get_user(new_timeout, p)) |
| 148 | return -EFAULT; |
| 149 | if ((new_timeout < 1) || (new_timeout > 63)) |
| 150 | return -EINVAL; |
| 151 | timeout = new_timeout; |
| 152 | advwdt_ping(); |
| 153 | /* Fall */ |
| 154 | |
| 155 | case WDIOC_GETTIMEOUT: |
| 156 | return put_user(timeout, p); |
| 157 | |
| 158 | case WDIOC_SETOPTIONS: |
| 159 | { |
| 160 | int options, retval = -EINVAL; |
| 161 | |
| 162 | if (get_user(options, p)) |
| 163 | return -EFAULT; |
| 164 | |
| 165 | if (options & WDIOS_DISABLECARD) { |
| 166 | advwdt_disable(); |
| 167 | retval = 0; |
| 168 | } |
| 169 | |
| 170 | if (options & WDIOS_ENABLECARD) { |
| 171 | advwdt_ping(); |
| 172 | retval = 0; |
| 173 | } |
| 174 | |
| 175 | return retval; |
| 176 | } |
| 177 | |
| 178 | default: |
| 179 | return -ENOIOCTLCMD; |
| 180 | } |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | static int |
| 185 | advwdt_open(struct inode *inode, struct file *file) |
| 186 | { |
| 187 | if (test_and_set_bit(0, &advwdt_is_open)) |
| 188 | return -EBUSY; |
| 189 | /* |
| 190 | * Activate |
| 191 | */ |
| 192 | |
| 193 | advwdt_ping(); |
| 194 | return nonseekable_open(inode, file); |
| 195 | } |
| 196 | |
| 197 | static int |
| 198 | advwdt_close(struct inode *inode, struct file *file) |
| 199 | { |
| 200 | if (adv_expect_close == 42) { |
| 201 | advwdt_disable(); |
| 202 | } else { |
| 203 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); |
| 204 | advwdt_ping(); |
| 205 | } |
| 206 | clear_bit(0, &advwdt_is_open); |
| 207 | adv_expect_close = 0; |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | /* |
| 212 | * Notifier for system down |
| 213 | */ |
| 214 | |
| 215 | static int |
| 216 | advwdt_notify_sys(struct notifier_block *this, unsigned long code, |
| 217 | void *unused) |
| 218 | { |
| 219 | if (code == SYS_DOWN || code == SYS_HALT) { |
| 220 | /* Turn the WDT off */ |
| 221 | advwdt_disable(); |
| 222 | } |
| 223 | return NOTIFY_DONE; |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * Kernel Interfaces |
| 228 | */ |
| 229 | |
| 230 | static struct file_operations advwdt_fops = { |
| 231 | .owner = THIS_MODULE, |
| 232 | .llseek = no_llseek, |
| 233 | .write = advwdt_write, |
| 234 | .ioctl = advwdt_ioctl, |
| 235 | .open = advwdt_open, |
| 236 | .release = advwdt_close, |
| 237 | }; |
| 238 | |
| 239 | static struct miscdevice advwdt_miscdev = { |
| 240 | .minor = WATCHDOG_MINOR, |
| 241 | .name = "watchdog", |
| 242 | .fops = &advwdt_fops, |
| 243 | }; |
| 244 | |
| 245 | /* |
| 246 | * The WDT needs to learn about soft shutdowns in order to |
| 247 | * turn the timebomb registers off. |
| 248 | */ |
| 249 | |
| 250 | static struct notifier_block advwdt_notifier = { |
| 251 | .notifier_call = advwdt_notify_sys, |
| 252 | }; |
| 253 | |
| 254 | static int __init |
| 255 | advwdt_init(void) |
| 256 | { |
| 257 | int ret; |
| 258 | |
| 259 | printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n"); |
| 260 | |
| 261 | if (timeout < 1 || timeout > 63) { |
| 262 | timeout = WATCHDOG_TIMEOUT; |
| 263 | printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n", |
| 264 | timeout); |
| 265 | } |
| 266 | |
| 267 | if (wdt_stop != wdt_start) { |
| 268 | if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { |
| 269 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| 270 | wdt_stop); |
| 271 | ret = -EIO; |
| 272 | goto out; |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { |
| 277 | printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| 278 | wdt_start); |
| 279 | ret = -EIO; |
| 280 | goto unreg_stop; |
| 281 | } |
| 282 | |
| 283 | ret = register_reboot_notifier(&advwdt_notifier); |
| 284 | if (ret != 0) { |
| 285 | printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", |
| 286 | ret); |
| 287 | goto unreg_regions; |
| 288 | } |
| 289 | |
| 290 | ret = misc_register(&advwdt_miscdev); |
| 291 | if (ret != 0) { |
| 292 | printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", |
| 293 | WATCHDOG_MINOR, ret); |
| 294 | goto unreg_reboot; |
| 295 | } |
| 296 | |
| 297 | printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", |
| 298 | timeout, nowayout); |
| 299 | |
| 300 | out: |
| 301 | return ret; |
| 302 | unreg_reboot: |
| 303 | unregister_reboot_notifier(&advwdt_notifier); |
| 304 | unreg_regions: |
| 305 | release_region(wdt_start, 1); |
| 306 | unreg_stop: |
| 307 | if (wdt_stop != wdt_start) |
| 308 | release_region(wdt_stop, 1); |
| 309 | goto out; |
| 310 | } |
| 311 | |
| 312 | static void __exit |
| 313 | advwdt_exit(void) |
| 314 | { |
| 315 | misc_deregister(&advwdt_miscdev); |
| 316 | unregister_reboot_notifier(&advwdt_notifier); |
| 317 | if(wdt_stop != wdt_start) |
| 318 | release_region(wdt_stop,1); |
| 319 | release_region(wdt_start,1); |
| 320 | } |
| 321 | |
| 322 | module_init(advwdt_init); |
| 323 | module_exit(advwdt_exit); |
| 324 | |
| 325 | MODULE_LICENSE("GPL"); |
| 326 | MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>"); |
| 327 | MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver"); |
| 328 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |