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
,
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
);