Jose Miguel Goncalves | b4cc4aa | 2005-09-06 17:05:30 -0700 | [diff] [blame] | 1 | /* |
| 2 | * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip |
| 3 | * |
| 4 | * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt> |
| 5 | * |
| 6 | * Based on w83877f_wdt.c by Scott Jennings, |
| 7 | * and wdt977.c by Woody Suwalski |
| 8 | * |
| 9 | * ----------------------- |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or |
| 12 | * modify it under the terms of the GNU General Public License |
| 13 | * as published by the Free Software Foundation; either version |
| 14 | * 2 of the License, or (at your option) any later version. |
| 15 | * |
| 16 | */ |
| 17 | |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/moduleparam.h> |
Jose Miguel Goncalves | b4cc4aa | 2005-09-06 17:05:30 -0700 | [diff] [blame] | 20 | #include <linux/types.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/fs.h> |
| 23 | #include <linux/miscdevice.h> |
| 24 | #include <linux/init.h> |
| 25 | #include <linux/ioport.h> |
| 26 | #include <linux/watchdog.h> |
| 27 | #include <linux/notifier.h> |
| 28 | #include <linux/reboot.h> |
| 29 | |
| 30 | #include <asm/io.h> |
| 31 | #include <asm/system.h> |
| 32 | #include <asm/uaccess.h> |
| 33 | |
| 34 | #define WATCHDOG_VERSION "1.00" |
| 35 | #define WATCHDOG_NAME "W83977F WDT" |
| 36 | #define PFX WATCHDOG_NAME ": " |
| 37 | #define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n" |
| 38 | |
| 39 | #define IO_INDEX_PORT 0x3F0 |
| 40 | #define IO_DATA_PORT (IO_INDEX_PORT+1) |
| 41 | |
| 42 | #define UNLOCK_DATA 0x87 |
| 43 | #define LOCK_DATA 0xAA |
| 44 | #define DEVICE_REGISTER 0x07 |
| 45 | |
| 46 | #define DEFAULT_TIMEOUT 45 /* default timeout in seconds */ |
| 47 | |
| 48 | static int timeout = DEFAULT_TIMEOUT; |
| 49 | static int timeoutW; /* timeout in watchdog counter units */ |
| 50 | static unsigned long timer_alive; |
| 51 | static int testmode; |
| 52 | static char expect_close; |
| 53 | static spinlock_t spinlock; |
| 54 | |
| 55 | module_param(timeout, int, 0); |
| 56 | MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")"); |
| 57 | module_param(testmode, int, 0); |
| 58 | MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0"); |
| 59 | |
Wim Van Sebroeck | 3908bb1 | 2005-09-11 23:58:22 +0200 | [diff] [blame] | 60 | static int nowayout = WATCHDOG_NOWAYOUT; |
Jose Miguel Goncalves | b4cc4aa | 2005-09-06 17:05:30 -0700 | [diff] [blame] | 61 | module_param(nowayout, int, 0); |
| 62 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); |
| 63 | |
| 64 | /* |
| 65 | * Start the watchdog |
| 66 | */ |
| 67 | |
| 68 | static int wdt_start(void) |
| 69 | { |
| 70 | unsigned long flags; |
| 71 | |
| 72 | spin_lock_irqsave(&spinlock, flags); |
| 73 | |
| 74 | /* Unlock the SuperIO chip */ |
| 75 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 76 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 77 | |
| 78 | /* |
| 79 | * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. |
| 80 | * F2 has the timeout in watchdog counter units. |
| 81 | * F3 is set to enable watchdog LED blink at timeout. |
| 82 | * F4 is used to just clear the TIMEOUT'ed state (bit 0). |
| 83 | */ |
| 84 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); |
| 85 | outb_p(0x08,IO_DATA_PORT); |
| 86 | outb_p(0xF2,IO_INDEX_PORT); |
| 87 | outb_p(timeoutW,IO_DATA_PORT); |
| 88 | outb_p(0xF3,IO_INDEX_PORT); |
| 89 | outb_p(0x08,IO_DATA_PORT); |
| 90 | outb_p(0xF4,IO_INDEX_PORT); |
| 91 | outb_p(0x00,IO_DATA_PORT); |
| 92 | |
| 93 | /* Set device Aux2 active */ |
| 94 | outb_p(0x30,IO_INDEX_PORT); |
| 95 | outb_p(0x01,IO_DATA_PORT); |
| 96 | |
| 97 | /* |
| 98 | * Select device Aux1 (dev=7) to set GP16 as the watchdog output |
| 99 | * (in reg E6) and GP13 as the watchdog LED output (in reg E3). |
| 100 | * Map GP16 at pin 119. |
| 101 | * In test mode watch the bit 0 on F4 to indicate "triggered" or |
| 102 | * check watchdog LED on SBC. |
| 103 | */ |
| 104 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); |
| 105 | outb_p(0x07,IO_DATA_PORT); |
| 106 | if (!testmode) |
| 107 | { |
| 108 | unsigned pin_map; |
| 109 | |
| 110 | outb_p(0xE6,IO_INDEX_PORT); |
| 111 | outb_p(0x0A,IO_DATA_PORT); |
| 112 | outb_p(0x2C,IO_INDEX_PORT); |
| 113 | pin_map = inb_p(IO_DATA_PORT); |
| 114 | pin_map |= 0x10; |
| 115 | pin_map &= ~(0x20); |
| 116 | outb_p(0x2C,IO_INDEX_PORT); |
| 117 | outb_p(pin_map,IO_DATA_PORT); |
| 118 | } |
| 119 | outb_p(0xE3,IO_INDEX_PORT); |
| 120 | outb_p(0x08,IO_DATA_PORT); |
| 121 | |
| 122 | /* Set device Aux1 active */ |
| 123 | outb_p(0x30,IO_INDEX_PORT); |
| 124 | outb_p(0x01,IO_DATA_PORT); |
| 125 | |
| 126 | /* Lock the SuperIO chip */ |
| 127 | outb_p(LOCK_DATA,IO_INDEX_PORT); |
| 128 | |
| 129 | spin_unlock_irqrestore(&spinlock, flags); |
| 130 | |
| 131 | printk(KERN_INFO PFX "activated.\n"); |
| 132 | |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | /* |
| 137 | * Stop the watchdog |
| 138 | */ |
| 139 | |
| 140 | static int wdt_stop(void) |
| 141 | { |
| 142 | unsigned long flags; |
| 143 | |
| 144 | spin_lock_irqsave(&spinlock, flags); |
| 145 | |
| 146 | /* Unlock the SuperIO chip */ |
| 147 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 148 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 149 | |
| 150 | /* |
| 151 | * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. |
| 152 | * F2 is reset to its default value (watchdog timer disabled). |
| 153 | * F3 is reset to its default state. |
| 154 | * F4 clears the TIMEOUT'ed state (bit 0) - back to default. |
| 155 | */ |
| 156 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); |
| 157 | outb_p(0x08,IO_DATA_PORT); |
| 158 | outb_p(0xF2,IO_INDEX_PORT); |
| 159 | outb_p(0xFF,IO_DATA_PORT); |
| 160 | outb_p(0xF3,IO_INDEX_PORT); |
| 161 | outb_p(0x00,IO_DATA_PORT); |
| 162 | outb_p(0xF4,IO_INDEX_PORT); |
| 163 | outb_p(0x00,IO_DATA_PORT); |
| 164 | outb_p(0xF2,IO_INDEX_PORT); |
| 165 | outb_p(0x00,IO_DATA_PORT); |
| 166 | |
| 167 | /* |
| 168 | * Select device Aux1 (dev=7) to set GP16 (in reg E6) and |
| 169 | * Gp13 (in reg E3) as inputs. |
| 170 | */ |
| 171 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); |
| 172 | outb_p(0x07,IO_DATA_PORT); |
| 173 | if (!testmode) |
| 174 | { |
| 175 | outb_p(0xE6,IO_INDEX_PORT); |
| 176 | outb_p(0x01,IO_DATA_PORT); |
| 177 | } |
| 178 | outb_p(0xE3,IO_INDEX_PORT); |
| 179 | outb_p(0x01,IO_DATA_PORT); |
| 180 | |
| 181 | /* Lock the SuperIO chip */ |
| 182 | outb_p(LOCK_DATA,IO_INDEX_PORT); |
| 183 | |
| 184 | spin_unlock_irqrestore(&spinlock, flags); |
| 185 | |
| 186 | printk(KERN_INFO PFX "shutdown.\n"); |
| 187 | |
| 188 | return 0; |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Send a keepalive ping to the watchdog |
| 193 | * This is done by simply re-writing the timeout to reg. 0xF2 |
| 194 | */ |
| 195 | |
| 196 | static int wdt_keepalive(void) |
| 197 | { |
| 198 | unsigned long flags; |
| 199 | |
| 200 | spin_lock_irqsave(&spinlock, flags); |
| 201 | |
| 202 | /* Unlock the SuperIO chip */ |
| 203 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 204 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 205 | |
| 206 | /* Select device Aux2 (device=8) to kick watchdog reg F2 */ |
| 207 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); |
| 208 | outb_p(0x08,IO_DATA_PORT); |
| 209 | outb_p(0xF2,IO_INDEX_PORT); |
| 210 | outb_p(timeoutW,IO_DATA_PORT); |
| 211 | |
| 212 | /* Lock the SuperIO chip */ |
| 213 | outb_p(LOCK_DATA,IO_INDEX_PORT); |
| 214 | |
| 215 | spin_unlock_irqrestore(&spinlock, flags); |
| 216 | |
| 217 | return 0; |
| 218 | } |
| 219 | |
| 220 | /* |
| 221 | * Set the watchdog timeout value |
| 222 | */ |
| 223 | |
| 224 | static int wdt_set_timeout(int t) |
| 225 | { |
| 226 | int tmrval; |
| 227 | |
| 228 | /* |
| 229 | * Convert seconds to watchdog counter time units, rounding up. |
| 230 | * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup |
| 231 | * value. This information is supplied in the PCM-5335 manual and was |
| 232 | * checked by me on a real board. This is a bit strange because W83977f |
| 233 | * datasheet says counter unit is in minutes! |
| 234 | */ |
| 235 | if (t < 15) |
| 236 | return -EINVAL; |
| 237 | |
| 238 | tmrval = ((t + 15) + 29) / 30; |
| 239 | |
| 240 | if (tmrval > 255) |
| 241 | return -EINVAL; |
| 242 | |
| 243 | /* |
| 244 | * timeout is the timeout in seconds, |
| 245 | * timeoutW is the timeout in watchdog counter units. |
| 246 | */ |
| 247 | timeoutW = tmrval; |
| 248 | timeout = (timeoutW * 30) - 15; |
| 249 | return 0; |
| 250 | } |
| 251 | |
| 252 | /* |
| 253 | * Get the watchdog status |
| 254 | */ |
| 255 | |
| 256 | static int wdt_get_status(int *status) |
| 257 | { |
| 258 | int new_status; |
| 259 | unsigned long flags; |
| 260 | |
| 261 | spin_lock_irqsave(&spinlock, flags); |
| 262 | |
| 263 | /* Unlock the SuperIO chip */ |
| 264 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 265 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); |
| 266 | |
| 267 | /* Select device Aux2 (device=8) to read watchdog reg F4 */ |
| 268 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); |
| 269 | outb_p(0x08,IO_DATA_PORT); |
| 270 | outb_p(0xF4,IO_INDEX_PORT); |
| 271 | new_status = inb_p(IO_DATA_PORT); |
| 272 | |
| 273 | /* Lock the SuperIO chip */ |
| 274 | outb_p(LOCK_DATA,IO_INDEX_PORT); |
| 275 | |
| 276 | spin_unlock_irqrestore(&spinlock, flags); |
| 277 | |
| 278 | *status = 0; |
| 279 | if (new_status & 1) |
| 280 | *status |= WDIOF_CARDRESET; |
| 281 | |
| 282 | return 0; |
| 283 | } |
| 284 | |
| 285 | |
| 286 | /* |
| 287 | * /dev/watchdog handling |
| 288 | */ |
| 289 | |
| 290 | static int wdt_open(struct inode *inode, struct file *file) |
| 291 | { |
| 292 | /* If the watchdog is alive we don't need to start it again */ |
| 293 | if( test_and_set_bit(0, &timer_alive) ) |
| 294 | return -EBUSY; |
| 295 | |
| 296 | if (nowayout) |
| 297 | __module_get(THIS_MODULE); |
| 298 | |
| 299 | wdt_start(); |
| 300 | return nonseekable_open(inode, file); |
| 301 | } |
| 302 | |
| 303 | static int wdt_release(struct inode *inode, struct file *file) |
| 304 | { |
| 305 | /* |
| 306 | * Shut off the timer. |
| 307 | * Lock it in if it's a module and we set nowayout |
| 308 | */ |
| 309 | if (expect_close == 42) |
| 310 | { |
| 311 | wdt_stop(); |
| 312 | clear_bit(0, &timer_alive); |
| 313 | } else { |
| 314 | wdt_keepalive(); |
| 315 | printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n"); |
| 316 | } |
| 317 | expect_close = 0; |
| 318 | return 0; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * wdt_write: |
| 323 | * @file: file handle to the watchdog |
| 324 | * @buf: buffer to write (unused as data does not matter here |
| 325 | * @count: count of bytes |
| 326 | * @ppos: pointer to the position to write. No seeks allowed |
| 327 | * |
| 328 | * A write to a watchdog device is defined as a keepalive signal. Any |
| 329 | * write of data will do, as we we don't define content meaning. |
| 330 | */ |
| 331 | |
| 332 | static ssize_t wdt_write(struct file *file, const char __user *buf, |
| 333 | size_t count, loff_t *ppos) |
| 334 | { |
| 335 | /* See if we got the magic character 'V' and reload the timer */ |
| 336 | if(count) |
| 337 | { |
| 338 | if (!nowayout) |
| 339 | { |
| 340 | size_t ofs; |
| 341 | |
| 342 | /* note: just in case someone wrote the magic character long ago */ |
| 343 | expect_close = 0; |
| 344 | |
| 345 | /* scan to see whether or not we got the magic character */ |
| 346 | for(ofs = 0; ofs != count; ofs++) |
| 347 | { |
| 348 | char c; |
| 349 | if (get_user(c, buf + ofs)) |
| 350 | return -EFAULT; |
| 351 | if (c == 'V') { |
| 352 | expect_close = 42; |
| 353 | } |
| 354 | } |
| 355 | } |
| 356 | |
| 357 | /* someone wrote to us, we should restart timer */ |
| 358 | wdt_keepalive(); |
| 359 | } |
| 360 | return count; |
| 361 | } |
| 362 | |
| 363 | /* |
| 364 | * wdt_ioctl: |
| 365 | * @inode: inode of the device |
| 366 | * @file: file handle to the device |
| 367 | * @cmd: watchdog command |
| 368 | * @arg: argument pointer |
| 369 | * |
| 370 | * The watchdog API defines a common set of functions for all watchdogs |
| 371 | * according to their available features. |
| 372 | */ |
| 373 | |
| 374 | static struct watchdog_info ident = { |
| 375 | .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, |
| 376 | .firmware_version = 1, |
| 377 | .identity = WATCHDOG_NAME, |
| 378 | }; |
| 379 | |
| 380 | static int wdt_ioctl(struct inode *inode, struct file *file, |
| 381 | unsigned int cmd, unsigned long arg) |
| 382 | { |
| 383 | int status; |
| 384 | int new_options, retval = -EINVAL; |
| 385 | int new_timeout; |
| 386 | union { |
| 387 | struct watchdog_info __user *ident; |
| 388 | int __user *i; |
| 389 | } uarg; |
| 390 | |
| 391 | uarg.i = (int __user *)arg; |
| 392 | |
| 393 | switch(cmd) |
| 394 | { |
| 395 | default: |
Samuel Tardieu | 795b89d | 2006-09-09 17:34:31 +0200 | [diff] [blame^] | 396 | return -ENOTTY; |
Jose Miguel Goncalves | b4cc4aa | 2005-09-06 17:05:30 -0700 | [diff] [blame] | 397 | |
| 398 | case WDIOC_GETSUPPORT: |
| 399 | return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0; |
| 400 | |
| 401 | case WDIOC_GETSTATUS: |
| 402 | wdt_get_status(&status); |
| 403 | return put_user(status, uarg.i); |
| 404 | |
| 405 | case WDIOC_GETBOOTSTATUS: |
| 406 | return put_user(0, uarg.i); |
| 407 | |
| 408 | case WDIOC_KEEPALIVE: |
| 409 | wdt_keepalive(); |
| 410 | return 0; |
| 411 | |
| 412 | case WDIOC_SETOPTIONS: |
| 413 | if (get_user (new_options, uarg.i)) |
| 414 | return -EFAULT; |
| 415 | |
| 416 | if (new_options & WDIOS_DISABLECARD) { |
| 417 | wdt_stop(); |
| 418 | retval = 0; |
| 419 | } |
| 420 | |
| 421 | if (new_options & WDIOS_ENABLECARD) { |
| 422 | wdt_start(); |
| 423 | retval = 0; |
| 424 | } |
| 425 | |
| 426 | return retval; |
| 427 | |
| 428 | case WDIOC_SETTIMEOUT: |
| 429 | if (get_user(new_timeout, uarg.i)) |
| 430 | return -EFAULT; |
| 431 | |
| 432 | if (wdt_set_timeout(new_timeout)) |
| 433 | return -EINVAL; |
| 434 | |
| 435 | wdt_keepalive(); |
| 436 | /* Fall */ |
| 437 | |
| 438 | case WDIOC_GETTIMEOUT: |
| 439 | return put_user(timeout, uarg.i); |
| 440 | |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, |
| 445 | void *unused) |
| 446 | { |
| 447 | if (code==SYS_DOWN || code==SYS_HALT) |
| 448 | wdt_stop(); |
| 449 | return NOTIFY_DONE; |
| 450 | } |
| 451 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 452 | static const struct file_operations wdt_fops= |
Jose Miguel Goncalves | b4cc4aa | 2005-09-06 17:05:30 -0700 | [diff] [blame] | 453 | { |
| 454 | .owner = THIS_MODULE, |
| 455 | .llseek = no_llseek, |
| 456 | .write = wdt_write, |
| 457 | .ioctl = wdt_ioctl, |
| 458 | .open = wdt_open, |
| 459 | .release = wdt_release, |
| 460 | }; |
| 461 | |
| 462 | static struct miscdevice wdt_miscdev= |
| 463 | { |
| 464 | .minor = WATCHDOG_MINOR, |
| 465 | .name = "watchdog", |
| 466 | .fops = &wdt_fops, |
| 467 | }; |
| 468 | |
| 469 | static struct notifier_block wdt_notifier = { |
| 470 | .notifier_call = wdt_notify_sys, |
| 471 | }; |
| 472 | |
| 473 | static int __init w83977f_wdt_init(void) |
| 474 | { |
| 475 | int rc; |
| 476 | |
| 477 | printk(KERN_INFO PFX DRIVER_VERSION); |
| 478 | |
| 479 | spin_lock_init(&spinlock); |
| 480 | |
| 481 | /* |
| 482 | * Check that the timeout value is within it's range ; |
| 483 | * if not reset to the default |
| 484 | */ |
| 485 | if (wdt_set_timeout(timeout)) { |
| 486 | wdt_set_timeout(DEFAULT_TIMEOUT); |
| 487 | printk(KERN_INFO PFX "timeout value must be 15<=timeout<=7635, using %d\n", |
| 488 | DEFAULT_TIMEOUT); |
| 489 | } |
| 490 | |
| 491 | if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) |
| 492 | { |
| 493 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| 494 | IO_INDEX_PORT); |
| 495 | rc = -EIO; |
| 496 | goto err_out; |
| 497 | } |
| 498 | |
| 499 | rc = misc_register(&wdt_miscdev); |
| 500 | if (rc) |
| 501 | { |
| 502 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", |
| 503 | wdt_miscdev.minor, rc); |
| 504 | goto err_out_region; |
| 505 | } |
| 506 | |
| 507 | rc = register_reboot_notifier(&wdt_notifier); |
| 508 | if (rc) |
| 509 | { |
| 510 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", |
| 511 | rc); |
| 512 | goto err_out_miscdev; |
| 513 | } |
| 514 | |
| 515 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n", |
| 516 | timeout, nowayout, testmode); |
| 517 | |
| 518 | return 0; |
| 519 | |
| 520 | err_out_miscdev: |
| 521 | misc_deregister(&wdt_miscdev); |
| 522 | err_out_region: |
| 523 | release_region(IO_INDEX_PORT,2); |
| 524 | err_out: |
| 525 | return rc; |
| 526 | } |
| 527 | |
| 528 | static void __exit w83977f_wdt_exit(void) |
| 529 | { |
| 530 | wdt_stop(); |
| 531 | misc_deregister(&wdt_miscdev); |
| 532 | unregister_reboot_notifier(&wdt_notifier); |
| 533 | release_region(IO_INDEX_PORT,2); |
| 534 | } |
| 535 | |
| 536 | module_init(w83977f_wdt_init); |
| 537 | module_exit(w83977f_wdt_exit); |
| 538 | |
| 539 | MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>"); |
| 540 | MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip"); |
| 541 | MODULE_LICENSE("GPL"); |
| 542 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |