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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 | ||
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> | |
24 | #include <linux/fs.h> | |
25 | #include <linux/miscdevice.h> | |
26 | #include <linux/watchdog.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/bitops.h> | |
29 | ||
30 | #include <asm/hardware.h> | |
31 | #include <asm/uaccess.h> | |
32 | ||
4bfdf378 | 33 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
34 | static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */ |
35 | static unsigned long wdt_status; | |
36 | ||
37 | #define WDT_IN_USE 0 | |
38 | #define WDT_OK_TO_CLOSE 1 | |
39 | ||
40 | static unsigned long wdt_tick_rate; | |
41 | ||
42 | static void | |
43 | wdt_enable(void) | |
44 | { | |
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); | |
49 | } | |
50 | ||
51 | static void | |
52 | wdt_disable(void) | |
53 | { | |
54 | ixp2000_reg_write(IXP2000_T4_CTL, 0); | |
55 | } | |
56 | ||
57 | static void | |
58 | wdt_keepalive(void) | |
59 | { | |
60 | ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); | |
61 | } | |
62 | ||
63 | static int | |
64 | ixp2000_wdt_open(struct inode *inode, struct file *file) | |
65 | { | |
66 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
67 | return -EBUSY; | |
68 | ||
69 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
70 | ||
71 | wdt_enable(); | |
72 | ||
73 | return nonseekable_open(inode, file); | |
74 | } | |
75 | ||
76 | static ssize_t | |
77 | ixp2000_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
78 | { | |
79 | if (len) { | |
80 | if (!nowayout) { | |
81 | size_t i; | |
82 | ||
83 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
84 | ||
85 | for (i = 0; i != len; i++) { | |
86 | char c; | |
87 | ||
88 | if (get_user(c, data + i)) | |
89 | return -EFAULT; | |
90 | if (c == 'V') | |
91 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
92 | } | |
93 | } | |
94 | wdt_keepalive(); | |
95 | } | |
96 | ||
97 | return len; | |
98 | } | |
99 | ||
100 | ||
101 | static struct watchdog_info ident = { | |
102 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | | |
103 | WDIOF_KEEPALIVEPING, | |
104 | .identity = "IXP2000 Watchdog", | |
105 | }; | |
106 | ||
107 | static int | |
108 | ixp2000_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
109 | unsigned long arg) | |
110 | { | |
111 | int ret = -ENOIOCTLCMD; | |
112 | int time; | |
113 | ||
114 | switch (cmd) { | |
115 | case WDIOC_GETSUPPORT: | |
116 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
117 | sizeof(ident)) ? -EFAULT : 0; | |
118 | break; | |
119 | ||
120 | case WDIOC_GETSTATUS: | |
121 | ret = put_user(0, (int *)arg); | |
122 | break; | |
123 | ||
124 | case WDIOC_GETBOOTSTATUS: | |
125 | ret = put_user(0, (int *)arg); | |
126 | break; | |
127 | ||
128 | case WDIOC_SETTIMEOUT: | |
129 | ret = get_user(time, (int *)arg); | |
130 | if (ret) | |
131 | break; | |
132 | ||
133 | if (time <= 0 || time > 60) { | |
134 | ret = -EINVAL; | |
135 | break; | |
136 | } | |
137 | ||
138 | heartbeat = time; | |
139 | wdt_keepalive(); | |
140 | /* Fall through */ | |
141 | ||
142 | case WDIOC_GETTIMEOUT: | |
143 | ret = put_user(heartbeat, (int *)arg); | |
144 | break; | |
145 | ||
146 | case WDIOC_KEEPALIVE: | |
147 | wdt_enable(); | |
148 | ret = 0; | |
149 | break; | |
150 | } | |
151 | ||
152 | return ret; | |
153 | } | |
154 | ||
155 | static int | |
156 | ixp2000_wdt_release(struct inode *inode, struct file *file) | |
157 | { | |
158 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { | |
159 | wdt_disable(); | |
160 | } else { | |
b36bbb6c | 161 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " |
1da177e4 LT |
162 | "timer will not stop\n"); |
163 | } | |
164 | ||
165 | clear_bit(WDT_IN_USE, &wdt_status); | |
166 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
171 | ||
172 | static struct file_operations ixp2000_wdt_fops = | |
173 | { | |
174 | .owner = THIS_MODULE, | |
175 | .llseek = no_llseek, | |
176 | .write = ixp2000_wdt_write, | |
177 | .ioctl = ixp2000_wdt_ioctl, | |
178 | .open = ixp2000_wdt_open, | |
179 | .release = ixp2000_wdt_release, | |
180 | }; | |
181 | ||
182 | static struct miscdevice ixp2000_wdt_miscdev = | |
183 | { | |
184 | .minor = WATCHDOG_MINOR, | |
185 | .name = "IXP2000 Watchdog", | |
186 | .fops = &ixp2000_wdt_fops, | |
187 | }; | |
188 | ||
189 | static int __init ixp2000_wdt_init(void) | |
190 | { | |
e4fe1981 LB |
191 | if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) { |
192 | printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n"); | |
193 | return -EIO; | |
194 | } | |
195 | ||
196 | wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256; | |
1da177e4 LT |
197 | |
198 | return misc_register(&ixp2000_wdt_miscdev); | |
199 | } | |
200 | ||
201 | static void __exit ixp2000_wdt_exit(void) | |
202 | { | |
203 | misc_deregister(&ixp2000_wdt_miscdev); | |
204 | } | |
205 | ||
206 | module_init(ixp2000_wdt_init); | |
207 | module_exit(ixp2000_wdt_exit); | |
208 | ||
209 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net">); | |
210 | MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog"); | |
211 | ||
212 | module_param(heartbeat, int, 0); | |
213 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | |
214 | ||
215 | module_param(nowayout, int, 0); | |
216 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | |
217 | ||
218 | MODULE_LICENSE("GPL"); | |
219 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
220 |