/* * w83627hf WDT driver * * (c) Copyright 2003 Pádraig Brady * * Based on advantechwdt.c which is based on wdt.c. * Original copyright messages: * * (c) Copyright 2000-2001 Marek Michalkiewicz * * (c) Copyright 1996 Alan Cox , All Rights Reserved. * http://www.redhat.com * * 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. * * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide * warranty for any of this software. This material is provided * "AS-IS" and at no charge. * * (c) Copyright 1995 Alan Cox */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define WATCHDOG_NAME "w83627hf WDT" #define PFX WATCHDOG_NAME ": " #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ static unsigned long wdt_is_open; static char expect_close; /* You must set this - there is no sane way to probe for this board. */ static int wdt_io = 0x2E; module_param(wdt_io, int, 0); MODULE_PARM_DESC(wdt_io, "w83627hf WDT io port (default 0x2E)"); static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ module_param(timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) "."); static int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); /* * Kernel methods. */ #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */ #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */ #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */ static void w83627hf_select_wd_register(void) { outb_p(0x87, WDT_EFER); /* Enter extended function mode */ outb_p(0x87, WDT_EFER); /* Again according to manual */ outb_p(0x07, WDT_EFER); /* point to logical device number reg */ outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */ outb_p(0x30, WDT_EFER); /* select CR30 */ outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */ } static void w83627hf_unselect_wd_register(void) { outb_p(0xAA, WDT_EFER); /* Leave extended function mode */ } /* tyan motherboards seem to set F5 to 0x4C ? * So explicitly init to appropriate value. */ static void w83627hf_init(void) { unsigned char t; w83627hf_select_wd_register(); outb_p(0xF6, WDT_EFER); /* Select CRF6 */ t=inb_p(WDT_EFDR); /* read CRF6 */ if (t != 0) { printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout); outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */ } outb_p(0xF5, WDT_EFER); /* Select CRF5 */ t=inb_p(WDT_EFDR); /* read CRF5 */ t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */ outb_p(t, WDT_EFDR); /* Write back to CRF5 */ w83627hf_unselect_wd_register(); } static void wdt_ctrl(int timeout) { w83627hf_select_wd_register(); outb_p(0xF6, WDT_EFER); /* Select CRF6 */ outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */ w83627hf_unselect_wd_register(); } static int wdt_ping(void) { wdt_ctrl(timeout); return 0; } static int wdt_disable(void) { wdt_ctrl(0); return 0; } static int wdt_set_heartbeat(int t) { if ((t < 1) || (t > 63)) return -EINVAL; timeout = t; return 0; } static ssize_t wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { if (count) { if (!nowayout) { size_t i; 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; } } wdt_ping(); } return count; } static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int __user *p = argp; int new_timeout; static struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "W83627HF WDT", }; switch (cmd) { case WDIOC_GETSUPPORT: if (copy_to_user(argp, &ident, sizeof(ident))) return -EFAULT; break; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_KEEPALIVE: wdt_ping(); break; case WDIOC_SETTIMEOUT: if (get_user(new_timeout, p)) return -EFAULT; if (wdt_set_heartbeat(new_timeout)) return -EINVAL; wdt_ping(); /* Fall */ case WDIOC_GETTIMEOUT: return put_user(timeout, p); case WDIOC_SETOPTIONS: { int options, retval = -EINVAL; if (get_user(options, p)) return -EFAULT; if (options & WDIOS_DISABLECARD) { wdt_disable(); retval = 0; } if (options & WDIOS_ENABLECARD) { wdt_ping(); retval = 0; } return retval; } default: return -ENOIOCTLCMD; } return 0; } static int wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &wdt_is_open)) return -EBUSY; /* * Activate */ wdt_ping(); return nonseekable_open(inode, file); } static int wdt_close(struct inode *inode, struct file *file) { if (expect_close == 42) { wdt_disable(); } else { printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); wdt_ping(); } expect_close = 0; clear_bit(0, &wdt_is_open); return 0; } /* * Notifier for system down */ static int wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) { /* Turn the WDT off */ wdt_disable(); } return NOTIFY_DONE; } /* * Kernel Interfaces */ static struct file_operations wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = wdt_write, .ioctl = wdt_ioctl, .open = wdt_open, .release = wdt_close, }; static struct miscdevice wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &wdt_fops, }; /* * The WDT needs to learn about soft shutdowns in order to * turn the timebomb registers off. */ static struct notifier_block wdt_notifier = { .notifier_call = wdt_notify_sys, }; static int __init wdt_init(void) { int ret; printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF Super I/O chip initialising.\n"); if (wdt_set_heartbeat(timeout)) { wdt_set_heartbeat(WATCHDOG_TIMEOUT); printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n", WATCHDOG_TIMEOUT); } if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", wdt_io); ret = -EIO; goto out; } w83627hf_init(); ret = register_reboot_notifier(&wdt_notifier); if (ret != 0) { printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret); goto unreg_regions; } ret = misc_register(&wdt_miscdev); if (ret != 0) { printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); goto unreg_reboot; } printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", timeout, nowayout); out: return ret; unreg_reboot: unregister_reboot_notifier(&wdt_notifier); unreg_regions: release_region(wdt_io, 1); goto out; } static void __exit wdt_exit(void) { misc_deregister(&wdt_miscdev); unregister_reboot_notifier(&wdt_notifier); release_region(wdt_io,1); } module_init(wdt_init); module_exit(wdt_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Pádraig Brady "); MODULE_DESCRIPTION("w83627hf WDT driver"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);