/* * w83697hf/hg WDT driver * * (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net> * (c) Copyright 2006 Marcus Junker <junker@anduras.de> * * Based on w83627hf_wdt.c which is based on advantechwdt.c * which is based on wdt.c. * Original copyright messages: * * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com> * * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> * * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>, * All Rights Reserved. * * 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 Marcus Junker nor ANDURAS AG admit liability nor provide * warranty for any of this software. This material is provided * "AS-IS" and at no charge. */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/types.h> #include <linux/miscdevice.h> #include <linux/watchdog.h> #include <linux/fs.h> #include <linux/ioport.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/init.h> #include <linux/spinlock.h> #include <linux/io.h> #include <linux/uaccess.h> #include <asm/system.h> #define WATCHDOG_NAME "w83697hf/hg WDT" #define PFX WATCHDOG_NAME ": " #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ #define WATCHDOG_EARLY_DISABLE 1 /* Disable until userland kicks in */ static unsigned long wdt_is_open; static char expect_close; static DEFINE_SPINLOCK(io_lock); /* 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, "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)"); 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 int nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static int early_disable = WATCHDOG_EARLY_DISABLE; module_param(early_disable, int, 0); MODULE_PARM_DESC(early_disable, "Watchdog gets disabled at boot time (default=" __MODULE_STRING(WATCHDOG_EARLY_DISABLE) ")"); /* * Kernel methods. */ #define W83697HF_EFER (wdt_io + 0) /* Extended Function Enable Register */ #define W83697HF_EFIR (wdt_io + 0) /* Extended Function Index Register (same as EFER) */ #define W83697HF_EFDR (wdt_io + 1) /* Extended Function Data Register */ static inline void w83697hf_unlock(void) { outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */ outb_p(0x87, W83697HF_EFER); /* Again according to manual */ } static inline void w83697hf_lock(void) { outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */ } /* * The three functions w83697hf_get_reg(), w83697hf_set_reg() and * w83697hf_write_timeout() must be called with the device unlocked. */ static unsigned char w83697hf_get_reg(unsigned char reg) { outb_p(reg, W83697HF_EFIR); return inb_p(W83697HF_EFDR); } static void w83697hf_set_reg(unsigned char reg, unsigned char data) { outb_p(reg, W83697HF_EFIR); outb_p(data, W83697HF_EFDR); } static void w83697hf_write_timeout(int timeout) { /* Write Timeout counter to CRF4 */ w83697hf_set_reg(0xF4, timeout); } static void w83697hf_select_wdt(void) { w83697hf_unlock(); w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */ } static inline void w83697hf_deselect_wdt(void) { w83697hf_lock(); } static void w83697hf_init(void) { unsigned char bbuf; w83697hf_select_wdt(); bbuf = w83697hf_get_reg(0x29); bbuf &= ~0x60; bbuf |= 0x20; /* Set pin 119 to WDTO# mode (= CR29, WDT0) */ w83697hf_set_reg(0x29, bbuf); bbuf = w83697hf_get_reg(0xF3); bbuf &= ~0x04; w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */ w83697hf_deselect_wdt(); } static void wdt_ping(void) { spin_lock(&io_lock); w83697hf_select_wdt(); w83697hf_write_timeout(timeout); w83697hf_deselect_wdt(); spin_unlock(&io_lock); } static void wdt_enable(void) { spin_lock(&io_lock); w83697hf_select_wdt(); w83697hf_write_timeout(timeout); w83697hf_set_reg(0x30, 1); /* Enable timer */ w83697hf_deselect_wdt(); spin_unlock(&io_lock); } static void wdt_disable(void) { spin_lock(&io_lock); w83697hf_select_wdt(); w83697hf_set_reg(0x30, 0); /* Disable timer */ w83697hf_write_timeout(0); w83697hf_deselect_wdt(); spin_unlock(&io_lock); } static unsigned char wdt_running(void) { unsigned char t; spin_lock(&io_lock); w83697hf_select_wdt(); t = w83697hf_get_reg(0xF4); /* Read timer */ w83697hf_deselect_wdt(); spin_unlock(&io_lock); return t; } 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 = "W83697HF 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_enable(); 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_enable(); 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) 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 w83697hf_check_wdt(void) { if (!request_region(wdt_io, 2, WATCHDOG_NAME)) { printk(KERN_ERR PFX "I/O address 0x%x already in use\n", wdt_io); return -EIO; } printk(KERN_DEBUG PFX "Looking for watchdog at address 0x%x\n", wdt_io); w83697hf_unlock(); if (w83697hf_get_reg(0x20) == 0x60) { printk(KERN_INFO PFX "watchdog found at address 0x%x\n", wdt_io); w83697hf_lock(); return 0; } /* Reprotect in case it was a compatible device */ w83697hf_lock(); printk(KERN_INFO PFX "watchdog not found at address 0x%x\n", wdt_io); release_region(wdt_io, 2); return -EIO; } static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 }; static int __init wdt_init(void) { int ret, i, found = 0; printk(KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n"); if (wdt_io == 0) { /* we will autodetect the W83697HF/HG watchdog */ for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) { wdt_io = w83697hf_ioports[i]; if (!w83697hf_check_wdt()) found++; } } else { if (!w83697hf_check_wdt()) found++; } if (!found) { printk(KERN_ERR PFX "No W83697HF/HG could be found\n"); ret = -EIO; goto out; } w83697hf_init(); if (early_disable) { if (wdt_running()) printk(KERN_WARNING PFX "Stopping previously enabled watchdog until userland kicks in\n"); wdt_disable(); } if (wdt_set_heartbeat(timeout)) { wdt_set_heartbeat(WATCHDOG_TIMEOUT); printk(KERN_INFO PFX "timeout value must be 1 <= timeout <= 255, using %d\n", WATCHDOG_TIMEOUT); } 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, 2); goto out; } static void __exit wdt_exit(void) { misc_deregister(&wdt_miscdev); unregister_reboot_notifier(&wdt_notifier); release_region(wdt_io, 2); } module_init(wdt_init); module_exit(wdt_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Samuel Tardieu <sam@rfc1149.net>"); MODULE_DESCRIPTION("w83697hf/hg WDT driver"); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);