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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 | ||
33 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | |
34 | static int nowayout = 1; | |
35 | #else | |
36 | static int nowayout = 0; | |
37 | #endif | |
38 | static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */ | |
39 | static unsigned long wdt_status; | |
40 | ||
41 | #define WDT_IN_USE 0 | |
42 | #define WDT_OK_TO_CLOSE 1 | |
43 | ||
44 | static unsigned long wdt_tick_rate; | |
45 | ||
46 | static void | |
47 | wdt_enable(void) | |
48 | { | |
49 | ixp2000_reg_write(IXP2000_RESET0, *(IXP2000_RESET0) | WDT_RESET_ENABLE); | |
50 | ixp2000_reg_write(IXP2000_TWDE, WDT_ENABLE); | |
51 | ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); | |
52 | ixp2000_reg_write(IXP2000_T4_CTL, TIMER_DIVIDER_256 | TIMER_ENABLE); | |
53 | } | |
54 | ||
55 | static void | |
56 | wdt_disable(void) | |
57 | { | |
58 | ixp2000_reg_write(IXP2000_T4_CTL, 0); | |
59 | } | |
60 | ||
61 | static void | |
62 | wdt_keepalive(void) | |
63 | { | |
64 | ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); | |
65 | } | |
66 | ||
67 | static int | |
68 | ixp2000_wdt_open(struct inode *inode, struct file *file) | |
69 | { | |
70 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
71 | return -EBUSY; | |
72 | ||
73 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
74 | ||
75 | wdt_enable(); | |
76 | ||
77 | return nonseekable_open(inode, file); | |
78 | } | |
79 | ||
80 | static ssize_t | |
81 | ixp2000_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
82 | { | |
83 | if (len) { | |
84 | if (!nowayout) { | |
85 | size_t i; | |
86 | ||
87 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
88 | ||
89 | for (i = 0; i != len; i++) { | |
90 | char c; | |
91 | ||
92 | if (get_user(c, data + i)) | |
93 | return -EFAULT; | |
94 | if (c == 'V') | |
95 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
96 | } | |
97 | } | |
98 | wdt_keepalive(); | |
99 | } | |
100 | ||
101 | return len; | |
102 | } | |
103 | ||
104 | ||
105 | static struct watchdog_info ident = { | |
106 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | | |
107 | WDIOF_KEEPALIVEPING, | |
108 | .identity = "IXP2000 Watchdog", | |
109 | }; | |
110 | ||
111 | static int | |
112 | ixp2000_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
113 | unsigned long arg) | |
114 | { | |
115 | int ret = -ENOIOCTLCMD; | |
116 | int time; | |
117 | ||
118 | switch (cmd) { | |
119 | case WDIOC_GETSUPPORT: | |
120 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
121 | sizeof(ident)) ? -EFAULT : 0; | |
122 | break; | |
123 | ||
124 | case WDIOC_GETSTATUS: | |
125 | ret = put_user(0, (int *)arg); | |
126 | break; | |
127 | ||
128 | case WDIOC_GETBOOTSTATUS: | |
129 | ret = put_user(0, (int *)arg); | |
130 | break; | |
131 | ||
132 | case WDIOC_SETTIMEOUT: | |
133 | ret = get_user(time, (int *)arg); | |
134 | if (ret) | |
135 | break; | |
136 | ||
137 | if (time <= 0 || time > 60) { | |
138 | ret = -EINVAL; | |
139 | break; | |
140 | } | |
141 | ||
142 | heartbeat = time; | |
143 | wdt_keepalive(); | |
144 | /* Fall through */ | |
145 | ||
146 | case WDIOC_GETTIMEOUT: | |
147 | ret = put_user(heartbeat, (int *)arg); | |
148 | break; | |
149 | ||
150 | case WDIOC_KEEPALIVE: | |
151 | wdt_enable(); | |
152 | ret = 0; | |
153 | break; | |
154 | } | |
155 | ||
156 | return ret; | |
157 | } | |
158 | ||
159 | static int | |
160 | ixp2000_wdt_release(struct inode *inode, struct file *file) | |
161 | { | |
162 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { | |
163 | wdt_disable(); | |
164 | } else { | |
b36bbb6c | 165 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " |
1da177e4 LT |
166 | "timer will not stop\n"); |
167 | } | |
168 | ||
169 | clear_bit(WDT_IN_USE, &wdt_status); | |
170 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | ||
176 | static struct file_operations ixp2000_wdt_fops = | |
177 | { | |
178 | .owner = THIS_MODULE, | |
179 | .llseek = no_llseek, | |
180 | .write = ixp2000_wdt_write, | |
181 | .ioctl = ixp2000_wdt_ioctl, | |
182 | .open = ixp2000_wdt_open, | |
183 | .release = ixp2000_wdt_release, | |
184 | }; | |
185 | ||
186 | static struct miscdevice ixp2000_wdt_miscdev = | |
187 | { | |
188 | .minor = WATCHDOG_MINOR, | |
189 | .name = "IXP2000 Watchdog", | |
190 | .fops = &ixp2000_wdt_fops, | |
191 | }; | |
192 | ||
193 | static int __init ixp2000_wdt_init(void) | |
194 | { | |
e4fe1981 LB |
195 | if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) { |
196 | printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n"); | |
197 | return -EIO; | |
198 | } | |
199 | ||
200 | wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256; | |
1da177e4 LT |
201 | |
202 | return misc_register(&ixp2000_wdt_miscdev); | |
203 | } | |
204 | ||
205 | static void __exit ixp2000_wdt_exit(void) | |
206 | { | |
207 | misc_deregister(&ixp2000_wdt_miscdev); | |
208 | } | |
209 | ||
210 | module_init(ixp2000_wdt_init); | |
211 | module_exit(ixp2000_wdt_exit); | |
212 | ||
213 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net">); | |
214 | MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog"); | |
215 | ||
216 | module_param(heartbeat, int, 0); | |
217 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | |
218 | ||
219 | module_param(nowayout, int, 0); | |
220 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | |
221 | ||
222 | MODULE_LICENSE("GPL"); | |
223 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
224 |