2 * drivers/watchdog/ixp2000_wdt.c
4 * Watchdog driver for Intel IXP2000 network processors
6 * Adapted from the IXP4xx watchdog driver by Lennert Buytenhek.
7 * The original version carries these notices:
9 * Author: Deepak Saxena <dsaxena@plexity.net>
11 * Copyright 2004 (c) MontaVista, Software, Inc.
12 * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
14 * This file is licensed under the terms of the GNU General Public
15 * License version 2. This program is licensed "as is" without any
16 * warranty of any kind, whether express or implied.
19 #include <linux/config.h>
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <linux/types.h>
23 #include <linux/kernel.h>
25 #include <linux/miscdevice.h>
26 #include <linux/watchdog.h>
27 #include <linux/init.h>
28 #include <linux/bitops.h>
30 #include <asm/hardware.h>
31 #include <asm/uaccess.h>
33 static int nowayout = WATCHDOG_NOWAYOUT;
34 static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */
35 static unsigned long wdt_status;
38 #define WDT_OK_TO_CLOSE 1
40 static unsigned long wdt_tick_rate;
45 ixp2000_reg_write(IXP2000_RESET0, *(IXP2000_RESET0) | WDT_RESET_ENABLE);
46 ixp2000_reg_write(IXP2000_TWDE, WDT_ENABLE);
47 ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
48 ixp2000_reg_write(IXP2000_T4_CTL, TIMER_DIVIDER_256 | TIMER_ENABLE);
54 ixp2000_reg_write(IXP2000_T4_CTL, 0);
60 ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate);
64 ixp2000_wdt_open(struct inode *inode, struct file *file)
66 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
69 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
73 return nonseekable_open(inode, file);
77 ixp2000_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
83 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
85 for (i = 0; i != len; i++) {
88 if (get_user(c, data + i))
91 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
101 static struct watchdog_info ident = {
102 .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
104 .identity = "IXP2000 Watchdog",
108 ixp2000_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
111 int ret = -ENOIOCTLCMD;
115 case WDIOC_GETSUPPORT:
116 ret = copy_to_user((struct watchdog_info *)arg, &ident,
117 sizeof(ident)) ? -EFAULT : 0;
120 case WDIOC_GETSTATUS:
121 ret = put_user(0, (int *)arg);
124 case WDIOC_GETBOOTSTATUS:
125 ret = put_user(0, (int *)arg);
128 case WDIOC_SETTIMEOUT:
129 ret = get_user(time, (int *)arg);
133 if (time <= 0 || time > 60) {
142 case WDIOC_GETTIMEOUT:
143 ret = put_user(heartbeat, (int *)arg);
146 case WDIOC_KEEPALIVE:
156 ixp2000_wdt_release(struct inode *inode, struct file *file)
158 if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
161 printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
162 "timer will not stop\n");
165 clear_bit(WDT_IN_USE, &wdt_status);
166 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
172 static struct file_operations ixp2000_wdt_fops =
174 .owner = THIS_MODULE,
176 .write = ixp2000_wdt_write,
177 .ioctl = ixp2000_wdt_ioctl,
178 .open = ixp2000_wdt_open,
179 .release = ixp2000_wdt_release,
182 static struct miscdevice ixp2000_wdt_miscdev =
184 .minor = WATCHDOG_MINOR,
185 .name = "IXP2000 Watchdog",
186 .fops = &ixp2000_wdt_fops,
189 static int __init ixp2000_wdt_init(void)
191 if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) {
192 printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n");
196 wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256;
198 return misc_register(&ixp2000_wdt_miscdev);
201 static void __exit ixp2000_wdt_exit(void)
203 misc_deregister(&ixp2000_wdt_miscdev);
206 module_init(ixp2000_wdt_init);
207 module_exit(ixp2000_wdt_exit);
209 MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net">);
210 MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog");
212 module_param(heartbeat, int, 0);
213 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
215 module_param(nowayout, int, 0);
216 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
218 MODULE_LICENSE("GPL");
219 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);