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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 | /* * 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 free_irq(IRQ_TIMER4, NULL); timer_alive = 0; #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; static struct watchdog_info ident= { 0, 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; } } 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) { if (machine_is_netwinder()) return -ENODEV; misc_register(&watchdog_miscdev); 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); } 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); |