| /* |
| * Advantech Single Board Computer WDT driver |
| * |
| * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> |
| * |
| * Based on acquirewdt.c which is based on wdt.c. |
| * Original copyright messages: |
| * |
| * (c) Copyright 1996 Alan Cox <alan@redhat.com>, 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 <alan@redhat.com> |
| * |
| * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> |
| * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT |
| * |
| * 16-Oct-2002 Rob Radez <rob@osinvestor.com> |
| * Clean up ioctls, clean up init + exit, add expect close support, |
| * add wdt_start and wdt_stop as parameters. |
| */ |
| |
| #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 <asm/io.h> |
| #include <asm/uaccess.h> |
| #include <asm/system.h> |
| |
| #define DRV_NAME "advantechwdt" |
| #define PFX DRV_NAME ": " |
| #define WATCHDOG_NAME "Advantech WDT" |
| #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ |
| |
| static unsigned long advwdt_is_open; |
| static char adv_expect_close; |
| |
| /* |
| * You must set these - there is no sane way to probe for this board. |
| * |
| * To enable or restart, write the timeout value in seconds (1 to 63) |
| * to I/O port wdt_start. To disable, read I/O port wdt_stop. |
| * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but |
| * check your manual (at least the PCA-6159 seems to be different - |
| * the manual says wdt_stop is 0x43, not 0x443). |
| * (0x43 is also a write-only control register for the 8254 timer!) |
| */ |
| |
| static int wdt_stop = 0x443; |
| module_param(wdt_stop, int, 0); |
| MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)"); |
| |
| static int wdt_start = 0x443; |
| module_param(wdt_start, int, 0); |
| MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)"); |
| |
| 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=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| |
| /* |
| * Watchdog Operations |
| */ |
| |
| static void |
| advwdt_ping(void) |
| { |
| /* Write a watchdog value */ |
| outb_p(timeout, wdt_start); |
| } |
| |
| static void |
| advwdt_disable(void) |
| { |
| inb_p(wdt_stop); |
| } |
| |
| static int |
| advwdt_set_heartbeat(int t) |
| { |
| if ((t < 1) || (t > 63)) |
| return -EINVAL; |
| |
| timeout = t; |
| return 0; |
| } |
| |
| /* |
| * /dev/watchdog handling |
| */ |
| |
| static ssize_t |
| advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
| { |
| if (count) { |
| if (!nowayout) { |
| size_t i; |
| |
| adv_expect_close = 0; |
| |
| for (i = 0; i != count; i++) { |
| char c; |
| if (get_user(c, buf+i)) |
| return -EFAULT; |
| if (c == 'V') |
| adv_expect_close = 42; |
| } |
| } |
| advwdt_ping(); |
| } |
| return count; |
| } |
| |
| static int |
| advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| int new_timeout; |
| void __user *argp = (void __user *)arg; |
| int __user *p = argp; |
| static struct watchdog_info ident = { |
| .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, |
| .firmware_version = 1, |
| .identity = WATCHDOG_NAME, |
| }; |
| |
| 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: |
| advwdt_ping(); |
| break; |
| |
| case WDIOC_SETTIMEOUT: |
| if (get_user(new_timeout, p)) |
| return -EFAULT; |
| if (advwdt_set_heartbeat(new_timeout)) |
| return -EINVAL; |
| advwdt_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) { |
| advwdt_disable(); |
| retval = 0; |
| } |
| |
| if (options & WDIOS_ENABLECARD) { |
| advwdt_ping(); |
| retval = 0; |
| } |
| |
| return retval; |
| } |
| |
| default: |
| return -ENOTTY; |
| } |
| return 0; |
| } |
| |
| static int |
| advwdt_open(struct inode *inode, struct file *file) |
| { |
| if (test_and_set_bit(0, &advwdt_is_open)) |
| return -EBUSY; |
| /* |
| * Activate |
| */ |
| |
| advwdt_ping(); |
| return nonseekable_open(inode, file); |
| } |
| |
| static int |
| advwdt_close(struct inode *inode, struct file *file) |
| { |
| if (adv_expect_close == 42) { |
| advwdt_disable(); |
| } else { |
| printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); |
| advwdt_ping(); |
| } |
| clear_bit(0, &advwdt_is_open); |
| adv_expect_close = 0; |
| return 0; |
| } |
| |
| /* |
| * Notifier for system down |
| */ |
| |
| static int |
| advwdt_notify_sys(struct notifier_block *this, unsigned long code, |
| void *unused) |
| { |
| if (code == SYS_DOWN || code == SYS_HALT) { |
| /* Turn the WDT off */ |
| advwdt_disable(); |
| } |
| return NOTIFY_DONE; |
| } |
| |
| /* |
| * Kernel Interfaces |
| */ |
| |
| static const struct file_operations advwdt_fops = { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .write = advwdt_write, |
| .ioctl = advwdt_ioctl, |
| .open = advwdt_open, |
| .release = advwdt_close, |
| }; |
| |
| static struct miscdevice advwdt_miscdev = { |
| .minor = WATCHDOG_MINOR, |
| .name = "watchdog", |
| .fops = &advwdt_fops, |
| }; |
| |
| /* |
| * The WDT needs to learn about soft shutdowns in order to |
| * turn the timebomb registers off. |
| */ |
| |
| static struct notifier_block advwdt_notifier = { |
| .notifier_call = advwdt_notify_sys, |
| }; |
| |
| /* |
| * Init & exit routines |
| */ |
| |
| static int __init |
| advwdt_init(void) |
| { |
| int ret; |
| |
| printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n"); |
| |
| if (wdt_stop != wdt_start) { |
| if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { |
| printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| wdt_stop); |
| ret = -EIO; |
| goto out; |
| } |
| } |
| |
| if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { |
| printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| wdt_start); |
| ret = -EIO; |
| goto unreg_stop; |
| } |
| |
| /* Check that the heartbeat value is within it's range ; if not reset to the default */ |
| if (advwdt_set_heartbeat(timeout)) { |
| advwdt_set_heartbeat(WATCHDOG_TIMEOUT); |
| printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n", |
| timeout); |
| } |
| |
| ret = register_reboot_notifier(&advwdt_notifier); |
| if (ret != 0) { |
| printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", |
| ret); |
| goto unreg_regions; |
| } |
| |
| ret = misc_register(&advwdt_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(&advwdt_notifier); |
| unreg_regions: |
| release_region(wdt_start, 1); |
| unreg_stop: |
| if (wdt_stop != wdt_start) |
| release_region(wdt_stop, 1); |
| goto out; |
| } |
| |
| static void __exit |
| advwdt_exit(void) |
| { |
| misc_deregister(&advwdt_miscdev); |
| unregister_reboot_notifier(&advwdt_notifier); |
| release_region(wdt_start,1); |
| if(wdt_stop != wdt_start) |
| release_region(wdt_stop,1); |
| } |
| |
| module_init(advwdt_init); |
| module_exit(advwdt_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>"); |
| MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver"); |
| MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |