| /* |
| * Intel 21285 watchdog driver |
| * Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998 |
| * |
| * based on |
| * |
| * SoftDog 0.05: A Software Watchdog Device |
| * |
| * (c) Copyright 1996 Alan Cox <alan@redhat.com>, 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. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/fs.h> |
| #include <linux/mm.h> |
| #include <linux/miscdevice.h> |
| #include <linux/watchdog.h> |
| #include <linux/reboot.h> |
| #include <linux/init.h> |
| #include <linux/interrupt.h> |
| #include <linux/smp_lock.h> |
| |
| #include <asm/irq.h> |
| #include <asm/uaccess.h> |
| #include <asm/hardware.h> |
| #include <asm/mach-types.h> |
| #include <asm/hardware/dec21285.h> |
| |
| /* |
| * Define this to stop the watchdog actually rebooting the machine. |
| */ |
| #undef ONLY_TESTING |
| |
| #define TIMER_MARGIN 60 /* (secs) Default is 1 minute */ |
| |
| #define FCLK (50*1000*1000) /* 50MHz */ |
| |
| static int soft_margin = TIMER_MARGIN; /* in seconds */ |
| static int timer_alive; |
| |
| #ifdef ONLY_TESTING |
| /* |
| * If the timer expires.. |
| */ |
| |
| static void watchdog_fire(int irq, void *dev_id, struct pt_regs *regs) |
| { |
| printk(KERN_CRIT "Watchdog: Would Reboot.\n"); |
| *CSR_TIMER4_CNTL = 0; |
| *CSR_TIMER4_CLR = 0; |
| } |
| #endif |
| |
| static void watchdog_ping(void) |
| { |
| /* |
| * Refresh the timer. |
| */ |
| *CSR_TIMER4_LOAD = soft_margin * (FCLK / 256); |
| } |
| |
| /* |
| * Allow only one person to hold it open |
| */ |
| |
| static int watchdog_open(struct inode *inode, struct file *file) |
| { |
| if(timer_alive) |
| return -EBUSY; |
| /* |
| * Ahead watchdog factor ten, Mr Sulu |
| */ |
| *CSR_TIMER4_CLR = 0; |
| watchdog_ping(); |
| *CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD |
| | TIMER_CNTL_DIV256; |
| #ifdef ONLY_TESTING |
| request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL); |
| #else |
| *CSR_SA110_CNTL |= 1 << 13; |
| MOD_INC_USE_COUNT; |
| #endif |
| timer_alive = 1; |
| return 0; |
| } |
| |
| static int watchdog_release(struct inode *inode, struct file *file) |
| { |
| #ifdef ONLY_TESTING |
| lock_kernel(); |
| free_irq(IRQ_TIMER4, NULL); |
| timer_alive = 0; |
| unlock_kernel(); |
| #else |
| /* |
| * It's irreversible! |
| */ |
| #endif |
| return 0; |
| } |
| |
| static ssize_t watchdog_write(struct file *file, const char *data, size_t len, loff_t *ppos) |
| { |
| /* Can't seek (pwrite) on this device */ |
| if (ppos != &file->f_pos) |
| return -ESPIPE; |
| |
| /* |
| * Refresh the timer. |
| */ |
| if(len) |
| { |
| watchdog_ping(); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int watchdog_ioctl(struct inode *inode, struct file *file, |
| unsigned int cmd, unsigned long arg) |
| { |
| int i, new_margin; |
| static struct watchdog_info ident= |
| { |
| WDIOF_SETTIMEOUT, |
| 0, |
| "Footbridge Watchdog" |
| }; |
| switch(cmd) |
| { |
| default: |
| return -ENOTTY; |
| case WDIOC_GETSUPPORT: |
| if(copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) |
| return -EFAULT; |
| return 0; |
| case WDIOC_GETSTATUS: |
| case WDIOC_GETBOOTSTATUS: |
| return put_user(0,(int *)arg); |
| case WDIOC_KEEPALIVE: |
| watchdog_ping(); |
| return 0; |
| case WDIOC_SETTIMEOUT: |
| if (get_user(new_margin, (int *)arg)) |
| return -EFAULT; |
| /* Arbitrary, can't find the card's limits */ |
| if ((new_marg < 0) || (new_margin > 60)) |
| return -EINVAL; |
| soft_margin = new_margin; |
| watchdog_ping(); |
| /* Fall */ |
| case WDIOC_GETTIMEOUT: |
| return put_user(soft_margin, (int *)arg); |
| } |
| } |
| |
| static struct file_operations watchdog_fops= |
| { |
| owner: THIS_MODULE, |
| write: watchdog_write, |
| ioctl: watchdog_ioctl, |
| open: watchdog_open, |
| release: watchdog_release, |
| }; |
| |
| static struct miscdevice watchdog_miscdev= |
| { |
| WATCHDOG_MINOR, |
| "watchdog", |
| &watchdog_fops |
| }; |
| |
| static int __init footbridge_watchdog_init(void) |
| { |
| int retval; |
| |
| if (machine_is_netwinder()) |
| return -ENODEV; |
| |
| retval = misc_register(&watchdog_miscdev); |
| if(retval < 0) |
| return retval; |
| |
| printk("Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n", |
| soft_margin); |
| if (machine_is_cats()) |
| printk("Warning: Watchdog reset may not work on this machine.\n"); |
| return 0; |
| } |
| |
| static void __exit footbridge_watchdog_exit(void) |
| { |
| misc_deregister(&watchdog_miscdev); |
| } |
| |
| EXPORT_NO_SYMBOLS; |
| |
| MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>"); |
| MODULE_DESCRIPTION("21285 watchdog driver"); |
| MODULE_LICENSE("GPL"); |
| |
| MODULE_PARM(soft_margin,"i"); |
| MODULE_PARM_DESC(soft_margin,"Watchdog timeout in seconds"); |
| |
| module_init(footbridge_watchdog_init); |
| module_exit(footbridge_watchdog_exit); |