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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip4 *5 * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)6 *7 * -----------------------8 *9 * -----------------------10 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>11 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT12 * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface13 * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts14 * from minutes to seconds.15 * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in16 * nwwatchdog_init.17 * 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks18 * remove limitiation to be used on19 * Netwinders only20 */21 22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt23 24#include <linux/module.h>25#include <linux/moduleparam.h>26#include <linux/types.h>27#include <linux/kernel.h>28#include <linux/fs.h>29#include <linux/miscdevice.h>30#include <linux/init.h>31#include <linux/ioport.h>32#include <linux/watchdog.h>33#include <linux/notifier.h>34#include <linux/reboot.h>35#include <linux/io.h>36#include <linux/uaccess.h>37 38#include <asm/mach-types.h>39 40#define WATCHDOG_VERSION "0.04"41#define WATCHDOG_NAME "Wdt977"42 43#define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */44#define IO_DATA_PORT (IO_INDEX_PORT + 1)45 46#define UNLOCK_DATA 0x8747#define LOCK_DATA 0xAA48#define DEVICE_REGISTER 0x0749 50 51#define DEFAULT_TIMEOUT 60 /* default timeout in seconds */52 53static int timeout = DEFAULT_TIMEOUT;54static int timeoutM; /* timeout in minutes */55static unsigned long timer_alive;56static int testmode;57static char expect_close;58static DEFINE_SPINLOCK(spinlock);59 60module_param(timeout, int, 0);61MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="62 __MODULE_STRING(DEFAULT_TIMEOUT) ")");63module_param(testmode, int, 0);64MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");65 66static bool nowayout = WATCHDOG_NOWAYOUT;67module_param(nowayout, bool, 0);68MODULE_PARM_DESC(nowayout,69 "Watchdog cannot be stopped once started (default="70 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");71 72/*73 * Start the watchdog74 */75 76static int wdt977_start(void)77{78 unsigned long flags;79 80 spin_lock_irqsave(&spinlock, flags);81 82 /* unlock the SuperIO chip */83 outb_p(UNLOCK_DATA, IO_INDEX_PORT);84 outb_p(UNLOCK_DATA, IO_INDEX_PORT);85 86 /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F487 * F2 has the timeout in minutes88 * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)89 * at timeout, and to reset timer on kbd/mouse activity (not impl.)90 * F4 is used to just clear the TIMEOUT'ed state (bit 0)91 */92 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);93 outb_p(0x08, IO_DATA_PORT);94 outb_p(0xF2, IO_INDEX_PORT);95 outb_p(timeoutM, IO_DATA_PORT);96 outb_p(0xF3, IO_INDEX_PORT);97 outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for98 kbd/mouse/LED */99 outb_p(0xF4, IO_INDEX_PORT);100 outb_p(0x00, IO_DATA_PORT);101 102 /* At last select device Aux1 (dev=7) and set GP16 as a103 * watchdog output. In test mode watch the bit 1 on F4 to104 * indicate "triggered"105 */106 if (!testmode) {107 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);108 outb_p(0x07, IO_DATA_PORT);109 outb_p(0xE6, IO_INDEX_PORT);110 outb_p(0x08, IO_DATA_PORT);111 }112 113 /* lock the SuperIO chip */114 outb_p(LOCK_DATA, IO_INDEX_PORT);115 116 spin_unlock_irqrestore(&spinlock, flags);117 pr_info("activated\n");118 119 return 0;120}121 122/*123 * Stop the watchdog124 */125 126static int wdt977_stop(void)127{128 unsigned long flags;129 spin_lock_irqsave(&spinlock, flags);130 131 /* unlock the SuperIO chip */132 outb_p(UNLOCK_DATA, IO_INDEX_PORT);133 outb_p(UNLOCK_DATA, IO_INDEX_PORT);134 135 /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4136 * F3 is reset to its default state137 * F4 can clear the TIMEOUT'ed state (bit 0) - back to default138 * We can not use GP17 as a PowerLed, as we use its usage as a RedLed139 */140 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);141 outb_p(0x08, IO_DATA_PORT);142 outb_p(0xF2, IO_INDEX_PORT);143 outb_p(0xFF, IO_DATA_PORT);144 outb_p(0xF3, IO_INDEX_PORT);145 outb_p(0x00, IO_DATA_PORT);146 outb_p(0xF4, IO_INDEX_PORT);147 outb_p(0x00, IO_DATA_PORT);148 outb_p(0xF2, IO_INDEX_PORT);149 outb_p(0x00, IO_DATA_PORT);150 151 /* at last select device Aux1 (dev=7) and set152 GP16 as a watchdog output */153 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);154 outb_p(0x07, IO_DATA_PORT);155 outb_p(0xE6, IO_INDEX_PORT);156 outb_p(0x08, IO_DATA_PORT);157 158 /* lock the SuperIO chip */159 outb_p(LOCK_DATA, IO_INDEX_PORT);160 161 spin_unlock_irqrestore(&spinlock, flags);162 pr_info("shutdown\n");163 164 return 0;165}166 167/*168 * Send a keepalive ping to the watchdog169 * This is done by simply re-writing the timeout to reg. 0xF2170 */171 172static int wdt977_keepalive(void)173{174 unsigned long flags;175 spin_lock_irqsave(&spinlock, flags);176 177 /* unlock the SuperIO chip */178 outb_p(UNLOCK_DATA, IO_INDEX_PORT);179 outb_p(UNLOCK_DATA, IO_INDEX_PORT);180 181 /* select device Aux2 (device=8) and kicks watchdog reg F2 */182 /* F2 has the timeout in minutes */183 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);184 outb_p(0x08, IO_DATA_PORT);185 outb_p(0xF2, IO_INDEX_PORT);186 outb_p(timeoutM, IO_DATA_PORT);187 188 /* lock the SuperIO chip */189 outb_p(LOCK_DATA, IO_INDEX_PORT);190 spin_unlock_irqrestore(&spinlock, flags);191 192 return 0;193}194 195/*196 * Set the watchdog timeout value197 */198 199static int wdt977_set_timeout(int t)200{201 int tmrval;202 203 /* convert seconds to minutes, rounding up */204 tmrval = (t + 59) / 60;205 206 if (machine_is_netwinder()) {207 /* we have a hw bug somewhere, so each 977 minute is actually208 * only 30sec. This limits the max timeout to half of device209 * max of 255 minutes...210 */211 tmrval += tmrval;212 }213 214 if (tmrval < 1 || tmrval > 255)215 return -EINVAL;216 217 /* timeout is the timeout in seconds, timeoutM is218 the timeout in minutes) */219 timeout = t;220 timeoutM = tmrval;221 return 0;222}223 224/*225 * Get the watchdog status226 */227 228static int wdt977_get_status(int *status)229{230 int new_status;231 unsigned long flags;232 233 spin_lock_irqsave(&spinlock, flags);234 235 /* unlock the SuperIO chip */236 outb_p(UNLOCK_DATA, IO_INDEX_PORT);237 outb_p(UNLOCK_DATA, IO_INDEX_PORT);238 239 /* select device Aux2 (device=8) and read watchdog reg F4 */240 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);241 outb_p(0x08, IO_DATA_PORT);242 outb_p(0xF4, IO_INDEX_PORT);243 new_status = inb_p(IO_DATA_PORT);244 245 /* lock the SuperIO chip */246 outb_p(LOCK_DATA, IO_INDEX_PORT);247 248 spin_unlock_irqrestore(&spinlock, flags);249 250 *status = 0;251 if (new_status & 1)252 *status |= WDIOF_CARDRESET;253 254 return 0;255}256 257 258/*259 * /dev/watchdog handling260 */261 262static int wdt977_open(struct inode *inode, struct file *file)263{264 /* If the watchdog is alive we don't need to start it again */265 if (test_and_set_bit(0, &timer_alive))266 return -EBUSY;267 268 if (nowayout)269 __module_get(THIS_MODULE);270 271 wdt977_start();272 return stream_open(inode, file);273}274 275static int wdt977_release(struct inode *inode, struct file *file)276{277 /*278 * Shut off the timer.279 * Lock it in if it's a module and we set nowayout280 */281 if (expect_close == 42) {282 wdt977_stop();283 clear_bit(0, &timer_alive);284 } else {285 wdt977_keepalive();286 pr_crit("Unexpected close, not stopping watchdog!\n");287 }288 expect_close = 0;289 return 0;290}291 292 293/*294 * wdt977_write:295 * @file: file handle to the watchdog296 * @buf: buffer to write (unused as data does not matter here297 * @count: count of bytes298 * @ppos: pointer to the position to write. No seeks allowed299 *300 * A write to a watchdog device is defined as a keepalive signal. Any301 * write of data will do, as we we don't define content meaning.302 */303 304static ssize_t wdt977_write(struct file *file, const char __user *buf,305 size_t count, loff_t *ppos)306{307 if (count) {308 if (!nowayout) {309 size_t i;310 311 /* In case it was set long ago */312 expect_close = 0;313 314 for (i = 0; i != count; i++) {315 char c;316 if (get_user(c, buf + i))317 return -EFAULT;318 if (c == 'V')319 expect_close = 42;320 }321 }322 323 /* someone wrote to us, we should restart timer */324 wdt977_keepalive();325 }326 return count;327}328 329static const struct watchdog_info ident = {330 .options = WDIOF_SETTIMEOUT |331 WDIOF_MAGICCLOSE |332 WDIOF_KEEPALIVEPING,333 .firmware_version = 1,334 .identity = WATCHDOG_NAME,335};336 337/*338 * wdt977_ioctl:339 * @inode: inode of the device340 * @file: file handle to the device341 * @cmd: watchdog command342 * @arg: argument pointer343 *344 * The watchdog API defines a common set of functions for all watchdogs345 * according to their available features.346 */347 348static long wdt977_ioctl(struct file *file, unsigned int cmd,349 unsigned long arg)350{351 int status;352 int new_options, retval = -EINVAL;353 int new_timeout;354 union {355 struct watchdog_info __user *ident;356 int __user *i;357 } uarg;358 359 uarg.i = (int __user *)arg;360 361 switch (cmd) {362 case WDIOC_GETSUPPORT:363 return copy_to_user(uarg.ident, &ident,364 sizeof(ident)) ? -EFAULT : 0;365 366 case WDIOC_GETSTATUS:367 wdt977_get_status(&status);368 return put_user(status, uarg.i);369 370 case WDIOC_GETBOOTSTATUS:371 return put_user(0, uarg.i);372 373 case WDIOC_SETOPTIONS:374 if (get_user(new_options, uarg.i))375 return -EFAULT;376 377 if (new_options & WDIOS_DISABLECARD) {378 wdt977_stop();379 retval = 0;380 }381 382 if (new_options & WDIOS_ENABLECARD) {383 wdt977_start();384 retval = 0;385 }386 387 return retval;388 389 case WDIOC_KEEPALIVE:390 wdt977_keepalive();391 return 0;392 393 case WDIOC_SETTIMEOUT:394 if (get_user(new_timeout, uarg.i))395 return -EFAULT;396 397 if (wdt977_set_timeout(new_timeout))398 return -EINVAL;399 400 wdt977_keepalive();401 fallthrough;402 403 case WDIOC_GETTIMEOUT:404 return put_user(timeout, uarg.i);405 406 default:407 return -ENOTTY;408 409 }410}411 412static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,413 void *unused)414{415 if (code == SYS_DOWN || code == SYS_HALT)416 wdt977_stop();417 return NOTIFY_DONE;418}419 420static const struct file_operations wdt977_fops = {421 .owner = THIS_MODULE,422 .write = wdt977_write,423 .unlocked_ioctl = wdt977_ioctl,424 .compat_ioctl = compat_ptr_ioctl,425 .open = wdt977_open,426 .release = wdt977_release,427};428 429static struct miscdevice wdt977_miscdev = {430 .minor = WATCHDOG_MINOR,431 .name = "watchdog",432 .fops = &wdt977_fops,433};434 435static struct notifier_block wdt977_notifier = {436 .notifier_call = wdt977_notify_sys,437};438 439static int __init wd977_init(void)440{441 int rc;442 443 pr_info("driver v%s\n", WATCHDOG_VERSION);444 445 /* Check that the timeout value is within its range;446 if not reset to the default */447 if (wdt977_set_timeout(timeout)) {448 wdt977_set_timeout(DEFAULT_TIMEOUT);449 pr_info("timeout value must be 60 < timeout < 15300, using %d\n",450 DEFAULT_TIMEOUT);451 }452 453 /* on Netwinder the IOports are already reserved by454 * arch/arm/mach-footbridge/netwinder-hw.c455 */456 if (!machine_is_netwinder()) {457 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {458 pr_err("I/O address 0x%04x already in use\n",459 IO_INDEX_PORT);460 rc = -EIO;461 goto err_out;462 }463 }464 465 rc = register_reboot_notifier(&wdt977_notifier);466 if (rc) {467 pr_err("cannot register reboot notifier (err=%d)\n", rc);468 goto err_out_region;469 }470 471 rc = misc_register(&wdt977_miscdev);472 if (rc) {473 pr_err("cannot register miscdev on minor=%d (err=%d)\n",474 wdt977_miscdev.minor, rc);475 goto err_out_reboot;476 }477 478 pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",479 timeout, nowayout, testmode);480 481 return 0;482 483err_out_reboot:484 unregister_reboot_notifier(&wdt977_notifier);485err_out_region:486 if (!machine_is_netwinder())487 release_region(IO_INDEX_PORT, 2);488err_out:489 return rc;490}491 492static void __exit wd977_exit(void)493{494 wdt977_stop();495 misc_deregister(&wdt977_miscdev);496 unregister_reboot_notifier(&wdt977_notifier);497 release_region(IO_INDEX_PORT, 2);498}499 500module_init(wd977_init);501module_exit(wd977_exit);502 503MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");504MODULE_DESCRIPTION("W83977AF Watchdog driver");505MODULE_LICENSE("GPL");506