diff options
Diffstat (limited to 'drivers/watchdog/ixp2000_wdt.c')
-rw-r--r-- | drivers/watchdog/ixp2000_wdt.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/watchdog/ixp2000_wdt.c b/drivers/watchdog/ixp2000_wdt.c new file mode 100644 index 00000000000..e86952a7168 --- /dev/null +++ b/drivers/watchdog/ixp2000_wdt.c | |||
@@ -0,0 +1,215 @@ | |||
1 | /* | ||
2 | * drivers/char/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/module.h> | ||
20 | #include <linux/moduleparam.h> | ||
21 | #include <linux/types.h> | ||
22 | #include <linux/timer.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 | #include <linux/uaccess.h> | ||
30 | #include <mach/hardware.h> | ||
31 | |||
32 | static int nowayout = WATCHDOG_NOWAYOUT; | ||
33 | static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */ | ||
34 | static unsigned long wdt_status; | ||
35 | static spinlock_t wdt_lock; | ||
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 wdt_enable(void) | ||
43 | { | ||
44 | spin_lock(&wdt_lock); | ||
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 | spin_unlock(&wdt_lock); | ||
50 | } | ||
51 | |||
52 | static void wdt_disable(void) | ||
53 | { | ||
54 | spin_lock(&wdt_lock); | ||
55 | ixp2000_reg_write(IXP2000_T4_CTL, 0); | ||
56 | spin_unlock(&wdt_lock); | ||
57 | } | ||
58 | |||
59 | static void wdt_keepalive(void) | ||
60 | { | ||
61 | spin_lock(&wdt_lock); | ||
62 | ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); | ||
63 | spin_unlock(&wdt_lock); | ||
64 | } | ||
65 | |||
66 | static int ixp2000_wdt_open(struct inode *inode, struct file *file) | ||
67 | { | ||
68 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | ||
69 | return -EBUSY; | ||
70 | |||
71 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
72 | |||
73 | wdt_enable(); | ||
74 | |||
75 | return nonseekable_open(inode, file); | ||
76 | } | ||
77 | |||
78 | static ssize_t ixp2000_wdt_write(struct file *file, const char *data, | ||
79 | size_t len, loff_t *ppos) | ||
80 | { | ||
81 | if (len) { | ||
82 | if (!nowayout) { | ||
83 | size_t i; | ||
84 | |||
85 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
86 | |||
87 | for (i = 0; i != len; i++) { | ||
88 | char c; | ||
89 | |||
90 | if (get_user(c, data + i)) | ||
91 | return -EFAULT; | ||
92 | if (c == 'V') | ||
93 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
94 | } | ||
95 | } | ||
96 | wdt_keepalive(); | ||
97 | } | ||
98 | |||
99 | return len; | ||
100 | } | ||
101 | |||
102 | |||
103 | static const struct watchdog_info ident = { | ||
104 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | | ||
105 | WDIOF_KEEPALIVEPING, | ||
106 | .identity = "IXP2000 Watchdog", | ||
107 | }; | ||
108 | |||
109 | static long ixp2000_wdt_ioctl(struct file *file, unsigned int cmd, | ||
110 | unsigned long arg) | ||
111 | { | ||
112 | int ret = -ENOTTY; | ||
113 | int time; | ||
114 | |||
115 | switch (cmd) { | ||
116 | case WDIOC_GETSUPPORT: | ||
117 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | ||
118 | sizeof(ident)) ? -EFAULT : 0; | ||
119 | break; | ||
120 | |||
121 | case WDIOC_GETSTATUS: | ||
122 | ret = put_user(0, (int *)arg); | ||
123 | break; | ||
124 | |||
125 | case WDIOC_GETBOOTSTATUS: | ||
126 | ret = put_user(0, (int *)arg); | ||
127 | break; | ||
128 | |||
129 | case WDIOC_KEEPALIVE: | ||
130 | wdt_enable(); | ||
131 | ret = 0; | ||
132 | break; | ||
133 | |||
134 | case WDIOC_SETTIMEOUT: | ||
135 | ret = get_user(time, (int *)arg); | ||
136 | if (ret) | ||
137 | break; | ||
138 | |||
139 | if (time <= 0 || time > 60) { | ||
140 | ret = -EINVAL; | ||
141 | break; | ||
142 | } | ||
143 | |||
144 | heartbeat = time; | ||
145 | wdt_keepalive(); | ||
146 | /* Fall through */ | ||
147 | |||
148 | case WDIOC_GETTIMEOUT: | ||
149 | ret = put_user(heartbeat, (int *)arg); | ||
150 | break; | ||
151 | } | ||
152 | |||
153 | return ret; | ||
154 | } | ||
155 | |||
156 | static int 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 | ||
161 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " | ||
162 | "timer will not stop\n"); | ||
163 | clear_bit(WDT_IN_USE, &wdt_status); | ||
164 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | ||
165 | |||
166 | return 0; | ||
167 | } | ||
168 | |||
169 | |||
170 | static const struct file_operations ixp2000_wdt_fops = { | ||
171 | .owner = THIS_MODULE, | ||
172 | .llseek = no_llseek, | ||
173 | .write = ixp2000_wdt_write, | ||
174 | .unlocked_ioctl = ixp2000_wdt_ioctl, | ||
175 | .open = ixp2000_wdt_open, | ||
176 | .release = ixp2000_wdt_release, | ||
177 | }; | ||
178 | |||
179 | static struct miscdevice ixp2000_wdt_miscdev = { | ||
180 | .minor = WATCHDOG_MINOR, | ||
181 | .name = "watchdog", | ||
182 | .fops = &ixp2000_wdt_fops, | ||
183 | }; | ||
184 | |||
185 | static int __init ixp2000_wdt_init(void) | ||
186 | { | ||
187 | if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) { | ||
188 | printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n"); | ||
189 | return -EIO; | ||
190 | } | ||
191 | wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256; | ||
192 | spin_lock_init(&wdt_lock); | ||
193 | return misc_register(&ixp2000_wdt_miscdev); | ||
194 | } | ||
195 | |||
196 | static void __exit ixp2000_wdt_exit(void) | ||
197 | { | ||
198 | misc_deregister(&ixp2000_wdt_miscdev); | ||
199 | } | ||
200 | |||
201 | module_init(ixp2000_wdt_init); | ||
202 | module_exit(ixp2000_wdt_exit); | ||
203 | |||
204 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); | ||
205 | MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog"); | ||
206 | |||
207 | module_param(heartbeat, int, 0); | ||
208 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | ||
209 | |||
210 | module_param(nowayout, int, 0); | ||
211 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | ||
212 | |||
213 | MODULE_LICENSE("GPL"); | ||
214 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
215 | |||