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1da177e4 LT |
1 | /* |
2 | * drivers/watchdog/ixp2000_wdt.c | |
3 | * | |
4 | * Watchdog driver for Intel IXP2000 network processors | |
5 | * | |
6 | * Adapted from the IXP4xx watchdog driver by Lennert Buytenhek. | |
7 | * The original version carries these notices: | |
8 | * | |
9 | * Author: Deepak Saxena <dsaxena@plexity.net> | |
10 | * | |
11 | * Copyright 2004 (c) MontaVista, Software, Inc. | |
12 | * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu> | |
13 | * | |
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. | |
17 | */ | |
18 | ||
1da177e4 LT |
19 | #include <linux/module.h> |
20 | #include <linux/moduleparam.h> | |
21 | #include <linux/types.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/fs.h> | |
24 | #include <linux/miscdevice.h> | |
25 | #include <linux/watchdog.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/bitops.h> | |
28 | ||
29 | #include <asm/hardware.h> | |
30 | #include <asm/uaccess.h> | |
31 | ||
4bfdf378 | 32 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
33 | static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */ |
34 | static unsigned long wdt_status; | |
35 | ||
36 | #define WDT_IN_USE 0 | |
37 | #define WDT_OK_TO_CLOSE 1 | |
38 | ||
39 | static unsigned long wdt_tick_rate; | |
40 | ||
41 | static void | |
42 | wdt_enable(void) | |
43 | { | |
44 | ixp2000_reg_write(IXP2000_RESET0, *(IXP2000_RESET0) | WDT_RESET_ENABLE); | |
45 | ixp2000_reg_write(IXP2000_TWDE, WDT_ENABLE); | |
46 | ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); | |
47 | ixp2000_reg_write(IXP2000_T4_CTL, TIMER_DIVIDER_256 | TIMER_ENABLE); | |
48 | } | |
49 | ||
50 | static void | |
51 | wdt_disable(void) | |
52 | { | |
53 | ixp2000_reg_write(IXP2000_T4_CTL, 0); | |
54 | } | |
55 | ||
56 | static void | |
57 | wdt_keepalive(void) | |
58 | { | |
59 | ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); | |
60 | } | |
61 | ||
62 | static int | |
63 | ixp2000_wdt_open(struct inode *inode, struct file *file) | |
64 | { | |
65 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
66 | return -EBUSY; | |
67 | ||
68 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
69 | ||
70 | wdt_enable(); | |
71 | ||
72 | return nonseekable_open(inode, file); | |
73 | } | |
74 | ||
75 | static ssize_t | |
76 | ixp2000_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
77 | { | |
78 | if (len) { | |
79 | if (!nowayout) { | |
80 | size_t i; | |
81 | ||
82 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
83 | ||
84 | for (i = 0; i != len; i++) { | |
85 | char c; | |
86 | ||
87 | if (get_user(c, data + i)) | |
88 | return -EFAULT; | |
89 | if (c == 'V') | |
90 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
91 | } | |
92 | } | |
93 | wdt_keepalive(); | |
94 | } | |
95 | ||
96 | return len; | |
97 | } | |
98 | ||
99 | ||
100 | static struct watchdog_info ident = { | |
101 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | | |
102 | WDIOF_KEEPALIVEPING, | |
103 | .identity = "IXP2000 Watchdog", | |
104 | }; | |
105 | ||
106 | static int | |
107 | ixp2000_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
108 | unsigned long arg) | |
109 | { | |
110 | int ret = -ENOIOCTLCMD; | |
111 | int time; | |
112 | ||
113 | switch (cmd) { | |
114 | case WDIOC_GETSUPPORT: | |
115 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
116 | sizeof(ident)) ? -EFAULT : 0; | |
117 | break; | |
118 | ||
119 | case WDIOC_GETSTATUS: | |
120 | ret = put_user(0, (int *)arg); | |
121 | break; | |
122 | ||
123 | case WDIOC_GETBOOTSTATUS: | |
124 | ret = put_user(0, (int *)arg); | |
125 | break; | |
126 | ||
127 | case WDIOC_SETTIMEOUT: | |
128 | ret = get_user(time, (int *)arg); | |
129 | if (ret) | |
130 | break; | |
131 | ||
132 | if (time <= 0 || time > 60) { | |
133 | ret = -EINVAL; | |
134 | break; | |
135 | } | |
136 | ||
137 | heartbeat = time; | |
138 | wdt_keepalive(); | |
139 | /* Fall through */ | |
140 | ||
141 | case WDIOC_GETTIMEOUT: | |
142 | ret = put_user(heartbeat, (int *)arg); | |
143 | break; | |
144 | ||
145 | case WDIOC_KEEPALIVE: | |
146 | wdt_enable(); | |
147 | ret = 0; | |
148 | break; | |
149 | } | |
150 | ||
151 | return ret; | |
152 | } | |
153 | ||
154 | static int | |
155 | ixp2000_wdt_release(struct inode *inode, struct file *file) | |
156 | { | |
157 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { | |
158 | wdt_disable(); | |
159 | } else { | |
b36bbb6c | 160 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " |
1da177e4 LT |
161 | "timer will not stop\n"); |
162 | } | |
163 | ||
164 | clear_bit(WDT_IN_USE, &wdt_status); | |
165 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
166 | ||
167 | return 0; | |
168 | } | |
169 | ||
170 | ||
62322d25 | 171 | static const struct file_operations ixp2000_wdt_fops = |
1da177e4 LT |
172 | { |
173 | .owner = THIS_MODULE, | |
174 | .llseek = no_llseek, | |
175 | .write = ixp2000_wdt_write, | |
176 | .ioctl = ixp2000_wdt_ioctl, | |
177 | .open = ixp2000_wdt_open, | |
178 | .release = ixp2000_wdt_release, | |
179 | }; | |
180 | ||
181 | static struct miscdevice ixp2000_wdt_miscdev = | |
182 | { | |
183 | .minor = WATCHDOG_MINOR, | |
2dab3cab | 184 | .name = "watchdog", |
1da177e4 LT |
185 | .fops = &ixp2000_wdt_fops, |
186 | }; | |
187 | ||
188 | static int __init ixp2000_wdt_init(void) | |
189 | { | |
e4fe1981 LB |
190 | if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) { |
191 | printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n"); | |
192 | return -EIO; | |
193 | } | |
194 | ||
195 | wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256; | |
1da177e4 LT |
196 | |
197 | return misc_register(&ixp2000_wdt_miscdev); | |
198 | } | |
199 | ||
200 | static void __exit ixp2000_wdt_exit(void) | |
201 | { | |
202 | misc_deregister(&ixp2000_wdt_miscdev); | |
203 | } | |
204 | ||
205 | module_init(ixp2000_wdt_init); | |
206 | module_exit(ixp2000_wdt_exit); | |
207 | ||
208 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net">); | |
209 | MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog"); | |
210 | ||
211 | module_param(heartbeat, int, 0); | |
212 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | |
213 | ||
214 | module_param(nowayout, int, 0); | |
215 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | |
216 | ||
217 | MODULE_LICENSE("GPL"); | |
218 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
219 |