/* * w83697ug/uf WDT driver * * (c) Copyright 2008 Flemming Fransen * reused original code to support w83697ug/uf. * * Based on w83627hf_wdt.c which is based on advantechwdt.c * which is based on wdt.c. * Original copyright messages: * * (c) Copyright 2007 Vlad Drukker * added support for W83627THF. * * (c) Copyright 2003 Pádraig Brady * * (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 */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #define WATCHDOG_NAME "w83697ug/uf WDT" #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ static unsigned long wdt_is_open; static char expect_close; static DEFINE_SPINLOCK(io_lock); static int wdt_io = 0x2e; module_param(wdt_io, int, 0); MODULE_PARM_DESC(wdt_io, "w83697ug/uf 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 <=255 (default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); 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) ")"); /* * 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 int w83697ug_select_wd_register(void) { unsigned char c; unsigned char version; outb_p(0x87, WDT_EFER); /* Enter extended function mode */ outb_p(0x87, WDT_EFER); /* Again according to manual */ outb(0x20, WDT_EFER); /* check chip version */ version = inb(WDT_EFDR); if (version == 0x68) { /* W83697UG */ pr_info("Watchdog chip version 0x%02x = W83697UG/UF found at 0x%04x\n", version, wdt_io); outb_p(0x2b, WDT_EFER); c = inb_p(WDT_EFDR); /* select WDT0 */ c &= ~0x04; outb_p(0x2b, WDT_EFER); outb_p(c, WDT_EFDR); /* set pin118 to WDT0 */ } else { pr_err("No W83697UG/UF could be found\n"); return -ENODEV; } 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 */ c = inb_p(WDT_EFDR); outb_p(c | 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */ return 0; } static void w83697ug_unselect_wd_register(void) { outb_p(0xAA, WDT_EFER); /* Leave extended function mode */ } static int w83697ug_init(void) { int ret; unsigned char t; ret = w83697ug_select_wd_register(); if (ret != 0) return ret; outb_p(0xF6, WDT_EFER); /* Select CRF6 */ t = inb_p(WDT_EFDR); /* read CRF6 */ if (t != 0) { pr_info("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 */ w83697ug_unselect_wd_register(); return 0; } static void wdt_ctrl(int timeout) { spin_lock(&io_lock); if (w83697ug_select_wd_register() < 0) { spin_unlock(&io_lock); return; } outb_p(0xF4, WDT_EFER); /* Select CRF4 */ outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */ w83697ug_unselect_wd_register(); spin_unlock(&io_lock); } 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 > 255) 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 long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { void __user *argp = (void __user *)arg; int __user *p = argp; int new_timeout; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "W83697UG 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_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; } 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); default: return -ENOTTY; } 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 { pr_crit("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) wdt_disable(); /* Turn the WDT off */ return NOTIFY_DONE; } /* * Kernel Interfaces */ static const struct file_operations wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = wdt_write, .unlocked_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; pr_info("WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising\n"); if (wdt_set_heartbeat(timeout)) { wdt_set_heartbeat(WATCHDOG_TIMEOUT); pr_info("timeout value must be 1<=timeout<=255, using %d\n", WATCHDOG_TIMEOUT); } if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { pr_err("I/O address 0x%04x already in use\n", wdt_io); ret = -EIO; goto out; } ret = w83697ug_init(); if (ret != 0) goto unreg_regions; ret = register_reboot_notifier(&wdt_notifier); if (ret != 0) { pr_err("cannot register reboot notifier (err=%d)\n", ret); goto unreg_regions; } ret = misc_register(&wdt_miscdev); if (ret != 0) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); goto unreg_reboot; } pr_info("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("Flemming Frandsen "); MODULE_DESCRIPTION("w83697ug/uf WDT driver"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);