/* * MixCom Watchdog: A Simple Hardware Watchdog Device * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis * * Author: Gergely Madarasz * * Copyright (c) 1999 ITConsult-Pro Co. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Version 0.1 (99/04/15): * - first version * * Version 0.2 (99/06/16): * - added kernel timer watchdog ping after close * since the hardware does not support watchdog shutdown * * Version 0.3 (99/06/21): * - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls * * Version 0.3.1 (99/06/22): * - allow module removal while internal timer is active, * print warning about probable reset * * Version 0.4 (99/11/15): * - support for one more type board * * Version 0.5 (2001/12/14) Matt Domsch * - added nowayout module option to override * CONFIG_WATCHDOG_NOWAYOUT * * Version 0.6 (2002/04/12): Rob Radez * - make mixcomwd_opened unsigned, * removed lock_kernel/unlock_kernel from mixcomwd_release, * modified ioctl a bit to conform to API * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #define VERSION "0.6" #define WATCHDOG_NAME "mixcomwd" #include #include #include #include #include #include #include #include #include #include #include #include #include /* * We have two types of cards that can be probed: * 1) The Mixcom cards: these cards can be found at addresses * 0x180, 0x280, 0x380 with an additional offset of 0xc10. * (Or 0xd90, 0xe90, 0xf90). * 2) The FlashCOM cards: these cards can be set up at * 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04. * (Or 0x304 -> 0x37c in 0x8 jumps). * Each card has it's own ID. */ #define MIXCOM_ID 0x11 #define FLASHCOM_ID 0x18 static struct { int ioport; int id; } mixcomwd_io_info[] = { /* The Mixcom cards */ {0x0d90, MIXCOM_ID}, {0x0e90, MIXCOM_ID}, {0x0f90, MIXCOM_ID}, /* The FlashCOM cards */ {0x0304, FLASHCOM_ID}, {0x030c, FLASHCOM_ID}, {0x0314, FLASHCOM_ID}, {0x031c, FLASHCOM_ID}, {0x0324, FLASHCOM_ID}, {0x032c, FLASHCOM_ID}, {0x0334, FLASHCOM_ID}, {0x033c, FLASHCOM_ID}, {0x0344, FLASHCOM_ID}, {0x034c, FLASHCOM_ID}, {0x0354, FLASHCOM_ID}, {0x035c, FLASHCOM_ID}, {0x0364, FLASHCOM_ID}, {0x036c, FLASHCOM_ID}, {0x0374, FLASHCOM_ID}, {0x037c, FLASHCOM_ID}, /* The end of the list */ {0x0000, 0}, }; static void mixcomwd_timerfun(unsigned long d); static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */ static int watchdog_port; static int mixcomwd_timer_alive; static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0); static char expect_close; 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) ")"); static void mixcomwd_ping(void) { outb_p(55, watchdog_port); return; } static void mixcomwd_timerfun(unsigned long d) { mixcomwd_ping(); mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); } /* * Allow only one person to hold it open */ static int mixcomwd_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &mixcomwd_opened)) return -EBUSY; mixcomwd_ping(); if (nowayout) /* * fops_get() code via open() has already done * a try_module_get() so it is safe to do the * __module_get(). */ __module_get(THIS_MODULE); else { if (mixcomwd_timer_alive) { del_timer(&mixcomwd_timer); mixcomwd_timer_alive = 0; } } return nonseekable_open(inode, file); } static int mixcomwd_release(struct inode *inode, struct file *file) { if (expect_close == 42) { if (mixcomwd_timer_alive) { pr_err("release called while internal timer alive\n"); return -EBUSY; } mixcomwd_timer_alive = 1; mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); } else pr_crit("WDT device closed unexpectedly. WDT will not stop!\n"); clear_bit(0, &mixcomwd_opened); expect_close = 0; return 0; } static ssize_t mixcomwd_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) { if (len) { if (!nowayout) { size_t i; /* In case it was set long ago */ expect_close = 0; for (i = 0; i != len; i++) { char c; if (get_user(c, data + i)) return -EFAULT; if (c == 'V') expect_close = 42; } } mixcomwd_ping(); } return len; } static long mixcomwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int __user *p = argp; int status; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "MixCOM watchdog", }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_GETSTATUS: status = mixcomwd_opened; if (!nowayout) status |= mixcomwd_timer_alive; return put_user(status, p); case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_KEEPALIVE: mixcomwd_ping(); break; default: return -ENOTTY; } return 0; } static const struct file_operations mixcomwd_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = mixcomwd_write, .unlocked_ioctl = mixcomwd_ioctl, .open = mixcomwd_open, .release = mixcomwd_release, }; static struct miscdevice mixcomwd_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &mixcomwd_fops, }; static int __init checkcard(int port, int card_id) { int id; if (!request_region(port, 1, "MixCOM watchdog")) return 0; id = inb_p(port); if (card_id == MIXCOM_ID) id &= 0x3f; if (id != card_id) { release_region(port, 1); return 0; } return 1; } static int __init mixcomwd_init(void) { int i, ret, found = 0; for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) { if (checkcard(mixcomwd_io_info[i].ioport, mixcomwd_io_info[i].id)) { found = 1; watchdog_port = mixcomwd_io_info[i].ioport; } } if (!found) { pr_err("No card detected, or port not available\n"); return -ENODEV; } ret = misc_register(&mixcomwd_miscdev); if (ret) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); goto error_misc_register_watchdog; } pr_info("MixCOM watchdog driver v%s, watchdog port at 0x%3x\n", VERSION, watchdog_port); return 0; error_misc_register_watchdog: release_region(watchdog_port, 1); watchdog_port = 0x0000; return ret; } static void __exit mixcomwd_exit(void) { if (!nowayout) { if (mixcomwd_timer_alive) { pr_warn("I quit now, hardware will probably reboot!\n"); del_timer_sync(&mixcomwd_timer); mixcomwd_timer_alive = 0; } } misc_deregister(&mixcomwd_miscdev); release_region(watchdog_port, 1); } module_init(mixcomwd_init); module_exit(mixcomwd_exit); MODULE_AUTHOR("Gergely Madarasz "); MODULE_DESCRIPTION("MixCom Watchdog driver"); MODULE_VERSION(VERSION); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);