// SPDX-License-Identifier: GPL-2.0-or-later /* * Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip * * (c) Copyright 1998 Rebel.com (Woody Suwalski ) * * ----------------------- * * ----------------------- * 14-Dec-2001 Matt Domsch * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts * from minutes to seconds. * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in * nwwatchdog_init. * 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks * remove limitiation to be used on * Netwinders only */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define WATCHDOG_VERSION "0.04" #define WATCHDOG_NAME "Wdt977" #define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */ #define IO_DATA_PORT (IO_INDEX_PORT + 1) #define UNLOCK_DATA 0x87 #define LOCK_DATA 0xAA #define DEVICE_REGISTER 0x07 #define DEFAULT_TIMEOUT 60 /* default timeout in seconds */ static int timeout = DEFAULT_TIMEOUT; static int timeoutM; /* timeout in minutes */ static unsigned long timer_alive; static int testmode; static char expect_close; static DEFINE_SPINLOCK(spinlock); module_param(timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")"); module_param(testmode, int, 0); MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0"); static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); /* * Start the watchdog */ static int wdt977_start(void) { unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 * F2 has the timeout in minutes * F3 could be set to the POWER LED blink (with GP17 set to PowerLed) * at timeout, and to reset timer on kbd/mouse activity (not impl.) * F4 is used to just clear the TIMEOUT'ed state (bit 0) */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(timeoutM, IO_DATA_PORT); outb_p(0xF3, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for kbd/mouse/LED */ outb_p(0xF4, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); /* At last select device Aux1 (dev=7) and set GP16 as a * watchdog output. In test mode watch the bit 1 on F4 to * indicate "triggered" */ if (!testmode) { outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x07, IO_DATA_PORT); outb_p(0xE6, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); } /* lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); pr_info("activated\n"); return 0; } /* * Stop the watchdog */ static int wdt977_stop(void) { unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 * F3 is reset to its default state * F4 can clear the TIMEOUT'ed state (bit 0) - back to default * We can not use GP17 as a PowerLed, as we use its usage as a RedLed */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(0xFF, IO_DATA_PORT); outb_p(0xF3, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); outb_p(0xF4, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(0x00, IO_DATA_PORT); /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x07, IO_DATA_PORT); outb_p(0xE6, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); /* lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); pr_info("shutdown\n"); return 0; } /* * Send a keepalive ping to the watchdog * This is done by simply re-writing the timeout to reg. 0xF2 */ static int wdt977_keepalive(void) { unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* select device Aux2 (device=8) and kicks watchdog reg F2 */ /* F2 has the timeout in minutes */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF2, IO_INDEX_PORT); outb_p(timeoutM, IO_DATA_PORT); /* lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); return 0; } /* * Set the watchdog timeout value */ static int wdt977_set_timeout(int t) { int tmrval; /* convert seconds to minutes, rounding up */ tmrval = (t + 59) / 60; if (machine_is_netwinder()) { /* we have a hw bug somewhere, so each 977 minute is actually * only 30sec. This limits the max timeout to half of device * max of 255 minutes... */ tmrval += tmrval; } if (tmrval < 1 || tmrval > 255) return -EINVAL; /* timeout is the timeout in seconds, timeoutM is the timeout in minutes) */ timeout = t; timeoutM = tmrval; return 0; } /* * Get the watchdog status */ static int wdt977_get_status(int *status) { int new_status; unsigned long flags; spin_lock_irqsave(&spinlock, flags); /* unlock the SuperIO chip */ outb_p(UNLOCK_DATA, IO_INDEX_PORT); outb_p(UNLOCK_DATA, IO_INDEX_PORT); /* select device Aux2 (device=8) and read watchdog reg F4 */ outb_p(DEVICE_REGISTER, IO_INDEX_PORT); outb_p(0x08, IO_DATA_PORT); outb_p(0xF4, IO_INDEX_PORT); new_status = inb_p(IO_DATA_PORT); /* lock the SuperIO chip */ outb_p(LOCK_DATA, IO_INDEX_PORT); spin_unlock_irqrestore(&spinlock, flags); *status = 0; if (new_status & 1) *status |= WDIOF_CARDRESET; return 0; } /* * /dev/watchdog handling */ static int wdt977_open(struct inode *inode, struct file *file) { /* If the watchdog is alive we don't need to start it again */ if (test_and_set_bit(0, &timer_alive)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); wdt977_start(); return stream_open(inode, file); } static int wdt977_release(struct inode *inode, struct file *file) { /* * Shut off the timer. * Lock it in if it's a module and we set nowayout */ if (expect_close == 42) { wdt977_stop(); clear_bit(0, &timer_alive); } else { wdt977_keepalive(); pr_crit("Unexpected close, not stopping watchdog!\n"); } expect_close = 0; return 0; } /* * wdt977_write: * @file: file handle to the watchdog * @buf: buffer to write (unused as data does not matter here * @count: count of bytes * @ppos: pointer to the position to write. No seeks allowed * * A write to a watchdog device is defined as a keepalive signal. Any * write of data will do, as we we don't define content meaning. */ static ssize_t wdt977_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { if (count) { if (!nowayout) { size_t i; /* In case it was set long ago */ expect_close = 0; for (i = 0; i != count; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') expect_close = 42; } } /* someone wrote to us, we should restart timer */ wdt977_keepalive(); } return count; } static const struct watchdog_info ident = { .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .firmware_version = 1, .identity = WATCHDOG_NAME, }; /* * wdt977_ioctl: * @inode: inode of the device * @file: file handle to the device * @cmd: watchdog command * @arg: argument pointer * * The watchdog API defines a common set of functions for all watchdogs * according to their available features. */ static long wdt977_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int status; int new_options, retval = -EINVAL; int new_timeout; union { struct watchdog_info __user *ident; int __user *i; } uarg; uarg.i = (int __user *)arg; switch (cmd) { case WDIOC_GETSUPPORT: return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0; case WDIOC_GETSTATUS: wdt977_get_status(&status); return put_user(status, uarg.i); case WDIOC_GETBOOTSTATUS: return put_user(0, uarg.i); case WDIOC_SETOPTIONS: if (get_user(new_options, uarg.i)) return -EFAULT; if (new_options & WDIOS_DISABLECARD) { wdt977_stop(); retval = 0; } if (new_options & WDIOS_ENABLECARD) { wdt977_start(); retval = 0; } return retval; case WDIOC_KEEPALIVE: wdt977_keepalive(); return 0; case WDIOC_SETTIMEOUT: if (get_user(new_timeout, uarg.i)) return -EFAULT; if (wdt977_set_timeout(new_timeout)) return -EINVAL; wdt977_keepalive(); fallthrough; case WDIOC_GETTIMEOUT: return put_user(timeout, uarg.i); default: return -ENOTTY; } } static int wdt977_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) wdt977_stop(); return NOTIFY_DONE; } static const struct file_operations wdt977_fops = { .owner = THIS_MODULE, .write = wdt977_write, .unlocked_ioctl = wdt977_ioctl, .compat_ioctl = compat_ptr_ioctl, .open = wdt977_open, .release = wdt977_release, }; static struct miscdevice wdt977_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &wdt977_fops, }; static struct notifier_block wdt977_notifier = { .notifier_call = wdt977_notify_sys, }; static int __init wd977_init(void) { int rc; pr_info("driver v%s\n", WATCHDOG_VERSION); /* Check that the timeout value is within its range; if not reset to the default */ if (wdt977_set_timeout(timeout)) { wdt977_set_timeout(DEFAULT_TIMEOUT); pr_info("timeout value must be 60 < timeout < 15300, using %d\n", DEFAULT_TIMEOUT); } /* on Netwinder the IOports are already reserved by * arch/arm/mach-footbridge/netwinder-hw.c */ if (!machine_is_netwinder()) { if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) { pr_err("I/O address 0x%04x already in use\n", IO_INDEX_PORT); rc = -EIO; goto err_out; } } rc = register_reboot_notifier(&wdt977_notifier); if (rc) { pr_err("cannot register reboot notifier (err=%d)\n", rc); goto err_out_region; } rc = misc_register(&wdt977_miscdev); if (rc) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", wdt977_miscdev.minor, rc); goto err_out_reboot; } pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n", timeout, nowayout, testmode); return 0; err_out_reboot: unregister_reboot_notifier(&wdt977_notifier); err_out_region: if (!machine_is_netwinder()) release_region(IO_INDEX_PORT, 2); err_out: return rc; } static void __exit wd977_exit(void) { wdt977_stop(); misc_deregister(&wdt977_miscdev); unregister_reboot_notifier(&wdt977_notifier); release_region(IO_INDEX_PORT, 2); } module_init(wd977_init); module_exit(wd977_exit); MODULE_AUTHOR("Woody Suwalski "); MODULE_DESCRIPTION("W83977AF Watchdog driver"); MODULE_LICENSE("GPL");