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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02002 * drivers/char/watchdog/ixp4xx_wdt.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Watchdog driver for Intel IXP4xx network processors
5 *
6 * Author: Deepak Saxena <dsaxena@plexity.net>
7 *
8 * Copyright 2004 (c) MontaVista, Software, Inc.
9 * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
10 *
11 * This file is licensed under the terms of the GNU General Public
12 * License version 2. This program is licensed "as is" without any
13 * warranty of any kind, whether express or implied.
14 */
15
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/types.h>
19#include <linux/kernel.h>
20#include <linux/fs.h>
21#include <linux/miscdevice.h>
22#include <linux/watchdog.h>
23#include <linux/init.h>
24#include <linux/bitops.h>
Wim Van Sebroeck089ab072008-07-15 11:46:11 +000025#include <linux/uaccess.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010026#include <mach/hardware.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Andrey Panin4bfdf372005-07-27 11:43:58 -070028static int nowayout = WATCHDOG_NOWAYOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070029static int heartbeat = 60; /* (secs) Default is 1 minute */
30static unsigned long wdt_status;
31static unsigned long boot_status;
Adrian Bunk92293762008-08-10 14:03:41 +030032static DEFINE_SPINLOCK(wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34#define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL)
35
36#define WDT_IN_USE 0
37#define WDT_OK_TO_CLOSE 1
38
Alan Cox20d35f32008-05-19 14:06:48 +010039static void wdt_enable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070040{
Alan Cox20d35f32008-05-19 14:06:48 +010041 spin_lock(&wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 *IXP4XX_OSWK = IXP4XX_WDT_KEY;
43 *IXP4XX_OSWE = 0;
44 *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat;
45 *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE;
46 *IXP4XX_OSWK = 0;
Alan Cox20d35f32008-05-19 14:06:48 +010047 spin_unlock(&wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048}
49
Alan Cox20d35f32008-05-19 14:06:48 +010050static void wdt_disable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
Alan Cox20d35f32008-05-19 14:06:48 +010052 spin_lock(&wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 *IXP4XX_OSWK = IXP4XX_WDT_KEY;
54 *IXP4XX_OSWE = 0;
55 *IXP4XX_OSWK = 0;
Alan Cox20d35f32008-05-19 14:06:48 +010056 spin_unlock(&wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
Alan Cox20d35f32008-05-19 14:06:48 +010059static int ixp4xx_wdt_open(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -070060{
61 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
62 return -EBUSY;
63
64 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 wdt_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 return nonseekable_open(inode, file);
67}
68
69static ssize_t
70ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
71{
72 if (len) {
73 if (!nowayout) {
74 size_t i;
75
76 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
77
78 for (i = 0; i != len; i++) {
79 char c;
80
81 if (get_user(c, data + i))
82 return -EFAULT;
83 if (c == 'V')
84 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
85 }
86 }
87 wdt_enable();
88 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 return len;
90}
91
92static struct watchdog_info ident = {
93 .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
94 WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
95 .identity = "IXP4xx Watchdog",
96};
97
98
Alan Cox20d35f32008-05-19 14:06:48 +010099static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd,
100 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101{
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200102 int ret = -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 int time;
104
105 switch (cmd) {
106 case WDIOC_GETSUPPORT:
107 ret = copy_to_user((struct watchdog_info *)arg, &ident,
108 sizeof(ident)) ? -EFAULT : 0;
109 break;
110
111 case WDIOC_GETSTATUS:
112 ret = put_user(0, (int *)arg);
113 break;
114
115 case WDIOC_GETBOOTSTATUS:
116 ret = put_user(boot_status, (int *)arg);
117 break;
118
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000119 case WDIOC_KEEPALIVE:
120 wdt_enable();
121 ret = 0;
122 break;
123
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 case WDIOC_SETTIMEOUT:
125 ret = get_user(time, (int *)arg);
126 if (ret)
127 break;
128
129 if (time <= 0 || time > 60) {
130 ret = -EINVAL;
131 break;
132 }
133
134 heartbeat = time;
135 wdt_enable();
136 /* Fall through */
137
138 case WDIOC_GETTIMEOUT:
139 ret = put_user(heartbeat, (int *)arg);
140 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 }
142 return ret;
143}
144
Alan Cox20d35f32008-05-19 14:06:48 +0100145static int ixp4xx_wdt_release(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146{
Alan Cox20d35f32008-05-19 14:06:48 +0100147 if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 wdt_disable();
Alan Cox20d35f32008-05-19 14:06:48 +0100149 else
Lennert Buytenhekb36bbb62005-06-28 20:44:46 -0700150 printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 "timer will not stop\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 clear_bit(WDT_IN_USE, &wdt_status);
153 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
154
155 return 0;
156}
157
158
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000159static const struct file_operations ixp4xx_wdt_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 .owner = THIS_MODULE,
161 .llseek = no_llseek,
162 .write = ixp4xx_wdt_write,
Alan Cox20d35f32008-05-19 14:06:48 +0100163 .unlocked_ioctl = ixp4xx_wdt_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 .open = ixp4xx_wdt_open,
165 .release = ixp4xx_wdt_release,
166};
167
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000168static struct miscdevice ixp4xx_wdt_miscdev = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 .minor = WATCHDOG_MINOR,
Olaf Hering2dab3ca2005-08-17 08:58:34 +0200170 .name = "watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 .fops = &ixp4xx_wdt_fops,
172};
173
174static int __init ixp4xx_wdt_init(void)
175{
176 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
Russell King0ba8b9b2008-08-10 18:08:10 +0100178 if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) {
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000179 printk(KERN_ERR "IXP4XXX Watchdog: Rev. A0 IXP42x CPU detected"
180 " - watchdog disabled\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 return -ENODEV;
183 }
Alan Cox20d35f32008-05-19 14:06:48 +0100184 spin_lock_init(&wdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ?
186 WDIOF_CARDRESET : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 ret = misc_register(&ixp4xx_wdt_miscdev);
188 if (ret == 0)
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000189 printk(KERN_INFO "IXP4xx Watchdog Timer: heartbeat %d sec\n",
190 heartbeat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 return ret;
192}
193
194static void __exit ixp4xx_wdt_exit(void)
195{
196 misc_deregister(&ixp4xx_wdt_miscdev);
197}
198
199
200module_init(ixp4xx_wdt_init);
201module_exit(ixp4xx_wdt_exit);
202
203MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
204MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog");
205
206module_param(heartbeat, int, 0);
207MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)");
208
209module_param(nowayout, int, 0);
210MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
211
212MODULE_LICENSE("GPL");
213MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
214