diff options
Diffstat (limited to 'drivers/watchdog/wdt285.c')
| -rw-r--r-- | drivers/watchdog/wdt285.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/watchdog/wdt285.c b/drivers/watchdog/wdt285.c new file mode 100644 index 000000000000..e4cf661dc890 --- /dev/null +++ b/drivers/watchdog/wdt285.c | |||
| @@ -0,0 +1,229 @@ | |||
| 1 | /* | ||
| 2 | * Intel 21285 watchdog driver | ||
| 3 | * Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998 | ||
| 4 | * | ||
| 5 | * based on | ||
| 6 | * | ||
| 7 | * SoftDog 0.05: A Software Watchdog Device | ||
| 8 | * | ||
| 9 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | ||
| 10 | * | ||
| 11 | * This program is free software; you can redistribute it and/or | ||
| 12 | * modify it under the terms of the GNU General Public License | ||
| 13 | * as published by the Free Software Foundation; either version | ||
| 14 | * 2 of the License, or (at your option) any later version. | ||
| 15 | * | ||
| 16 | */ | ||
| 17 | |||
| 18 | #include <linux/module.h> | ||
| 19 | #include <linux/moduleparam.h> | ||
| 20 | #include <linux/types.h> | ||
| 21 | #include <linux/kernel.h> | ||
| 22 | #include <linux/fs.h> | ||
| 23 | #include <linux/mm.h> | ||
| 24 | #include <linux/miscdevice.h> | ||
| 25 | #include <linux/watchdog.h> | ||
| 26 | #include <linux/reboot.h> | ||
| 27 | #include <linux/init.h> | ||
| 28 | #include <linux/interrupt.h> | ||
| 29 | |||
| 30 | #include <asm/irq.h> | ||
| 31 | #include <asm/uaccess.h> | ||
| 32 | #include <asm/hardware.h> | ||
| 33 | #include <asm/mach-types.h> | ||
| 34 | #include <asm/hardware/dec21285.h> | ||
| 35 | |||
| 36 | /* | ||
| 37 | * Define this to stop the watchdog actually rebooting the machine. | ||
| 38 | */ | ||
| 39 | #undef ONLY_TESTING | ||
| 40 | |||
| 41 | static unsigned int soft_margin = 60; /* in seconds */ | ||
| 42 | static unsigned int reload; | ||
| 43 | static unsigned long timer_alive; | ||
| 44 | |||
| 45 | #ifdef ONLY_TESTING | ||
| 46 | /* | ||
| 47 | * If the timer expires.. | ||
| 48 | */ | ||
| 49 | static void watchdog_fire(int irq, void *dev_id) | ||
| 50 | { | ||
| 51 | printk(KERN_CRIT "Watchdog: Would Reboot.\n"); | ||
| 52 | *CSR_TIMER4_CNTL = 0; | ||
| 53 | *CSR_TIMER4_CLR = 0; | ||
| 54 | } | ||
| 55 | #endif | ||
| 56 | |||
| 57 | /* | ||
| 58 | * Refresh the timer. | ||
| 59 | */ | ||
| 60 | static void watchdog_ping(void) | ||
| 61 | { | ||
| 62 | *CSR_TIMER4_LOAD = reload; | ||
| 63 | } | ||
| 64 | |||
| 65 | /* | ||
| 66 | * Allow only one person to hold it open | ||
| 67 | */ | ||
| 68 | static int watchdog_open(struct inode *inode, struct file *file) | ||
| 69 | { | ||
| 70 | int ret; | ||
| 71 | |||
| 72 | if (*CSR_SA110_CNTL & (1 << 13)) | ||
| 73 | return -EBUSY; | ||
| 74 | |||
| 75 | if (test_and_set_bit(1, &timer_alive)) | ||
| 76 | return -EBUSY; | ||
| 77 | |||
| 78 | reload = soft_margin * (mem_fclk_21285 / 256); | ||
| 79 | |||
| 80 | *CSR_TIMER4_CLR = 0; | ||
| 81 | watchdog_ping(); | ||
| 82 | *CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD | ||
| 83 | | TIMER_CNTL_DIV256; | ||
| 84 | |||
| 85 | #ifdef ONLY_TESTING | ||
| 86 | ret = request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL); | ||
| 87 | if (ret) { | ||
| 88 | *CSR_TIMER4_CNTL = 0; | ||
| 89 | clear_bit(1, &timer_alive); | ||
| 90 | } | ||
| 91 | #else | ||
| 92 | /* | ||
| 93 | * Setting this bit is irreversible; once enabled, there is | ||
| 94 | * no way to disable the watchdog. | ||
| 95 | */ | ||
| 96 | *CSR_SA110_CNTL |= 1 << 13; | ||
| 97 | |||
| 98 | ret = 0; | ||
| 99 | #endif | ||
| 100 | nonseekable_open(inode, file); | ||
| 101 | return ret; | ||
| 102 | } | ||
| 103 | |||
| 104 | /* | ||
| 105 | * Shut off the timer. | ||
| 106 | * Note: if we really have enabled the watchdog, there | ||
| 107 | * is no way to turn off. | ||
| 108 | */ | ||
| 109 | static int watchdog_release(struct inode *inode, struct file *file) | ||
| 110 | { | ||
| 111 | #ifdef ONLY_TESTING | ||
| 112 | free_irq(IRQ_TIMER4, NULL); | ||
| 113 | clear_bit(1, &timer_alive); | ||
| 114 | #endif | ||
| 115 | return 0; | ||
| 116 | } | ||
| 117 | |||
| 118 | static ssize_t | ||
| 119 | watchdog_write(struct file *file, const char *data, size_t len, loff_t *ppos) | ||
| 120 | { | ||
| 121 | /* | ||
| 122 | * Refresh the timer. | ||
| 123 | */ | ||
| 124 | if (len) | ||
| 125 | watchdog_ping(); | ||
| 126 | |||
| 127 | return len; | ||
| 128 | } | ||
| 129 | |||
| 130 | static struct watchdog_info ident = { | ||
| 131 | .options = WDIOF_SETTIMEOUT, | ||
| 132 | .identity = "Footbridge Watchdog", | ||
| 133 | }; | ||
| 134 | |||
| 135 | static int | ||
| 136 | watchdog_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
| 137 | unsigned long arg) | ||
| 138 | { | ||
| 139 | unsigned int new_margin; | ||
| 140 | int ret = -ENOTTY; | ||
| 141 | |||
| 142 | switch(cmd) { | ||
| 143 | case WDIOC_GETSUPPORT: | ||
| 144 | ret = 0; | ||
| 145 | if (copy_to_user((void *)arg, &ident, sizeof(ident))) | ||
| 146 | ret = -EFAULT; | ||
| 147 | break; | ||
| 148 | |||
| 149 | case WDIOC_GETSTATUS: | ||
| 150 | case WDIOC_GETBOOTSTATUS: | ||
| 151 | ret = put_user(0,(int *)arg); | ||
| 152 | break; | ||
| 153 | |||
| 154 | case WDIOC_KEEPALIVE: | ||
| 155 | watchdog_ping(); | ||
| 156 | ret = 0; | ||
| 157 | break; | ||
| 158 | |||
| 159 | case WDIOC_SETTIMEOUT: | ||
| 160 | ret = get_user(new_margin, (int *)arg); | ||
| 161 | if (ret) | ||
| 162 | break; | ||
| 163 | |||
| 164 | /* Arbitrary, can't find the card's limits */ | ||
| 165 | if (new_margin < 0 || new_margin > 60) { | ||
| 166 | ret = -EINVAL; | ||
| 167 | break; | ||
| 168 | } | ||
| 169 | |||
| 170 | soft_margin = new_margin; | ||
| 171 | reload = soft_margin * (mem_fclk_21285 / 256); | ||
| 172 | watchdog_ping(); | ||
| 173 | /* Fall */ | ||
| 174 | case WDIOC_GETTIMEOUT: | ||
| 175 | ret = put_user(soft_margin, (int *)arg); | ||
| 176 | break; | ||
| 177 | } | ||
| 178 | return ret; | ||
| 179 | } | ||
| 180 | |||
| 181 | static const struct file_operations watchdog_fops = { | ||
| 182 | .owner = THIS_MODULE, | ||
| 183 | .llseek = no_llseek, | ||
| 184 | .write = watchdog_write, | ||
| 185 | .ioctl = watchdog_ioctl, | ||
| 186 | .open = watchdog_open, | ||
| 187 | .release = watchdog_release, | ||
| 188 | }; | ||
| 189 | |||
| 190 | static struct miscdevice watchdog_miscdev = { | ||
| 191 | .minor = WATCHDOG_MINOR, | ||
| 192 | .name = "watchdog", | ||
| 193 | .fops = &watchdog_fops, | ||
| 194 | }; | ||
| 195 | |||
| 196 | static int __init footbridge_watchdog_init(void) | ||
| 197 | { | ||
| 198 | int retval; | ||
| 199 | |||
| 200 | if (machine_is_netwinder()) | ||
| 201 | return -ENODEV; | ||
| 202 | |||
| 203 | retval = misc_register(&watchdog_miscdev); | ||
| 204 | if (retval < 0) | ||
| 205 | return retval; | ||
| 206 | |||
| 207 | printk("Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n", | ||
| 208 | soft_margin); | ||
| 209 | |||
| 210 | if (machine_is_cats()) | ||
| 211 | printk("Warning: Watchdog reset may not work on this machine.\n"); | ||
| 212 | return 0; | ||
| 213 | } | ||
| 214 | |||
| 215 | static void __exit footbridge_watchdog_exit(void) | ||
| 216 | { | ||
| 217 | misc_deregister(&watchdog_miscdev); | ||
| 218 | } | ||
| 219 | |||
| 220 | MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>"); | ||
| 221 | MODULE_DESCRIPTION("Footbridge watchdog driver"); | ||
| 222 | MODULE_LICENSE("GPL"); | ||
| 223 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
| 224 | |||
| 225 | module_param(soft_margin, int, 0); | ||
| 226 | MODULE_PARM_DESC(soft_margin,"Watchdog timeout in seconds"); | ||
| 227 | |||
| 228 | module_init(footbridge_watchdog_init); | ||
| 229 | module_exit(footbridge_watchdog_exit); | ||
