Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
f30c2269 | 2 | * drivers/char/watchdog/ixp2000_wdt.c |
1da177e4 LT |
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> | |
640b4f68 | 28 | #include <linux/uaccess.h> |
a09e64fb | 29 | #include <mach/hardware.h> |
1da177e4 | 30 | |
4bfdf378 | 31 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
32 | static unsigned int heartbeat = 60; /* (secs) Default is 1 minute */ |
33 | static unsigned long wdt_status; | |
640b4f68 | 34 | static spinlock_t wdt_lock; |
1da177e4 LT |
35 | |
36 | #define WDT_IN_USE 0 | |
37 | #define WDT_OK_TO_CLOSE 1 | |
38 | ||
39 | static unsigned long wdt_tick_rate; | |
40 | ||
640b4f68 | 41 | static void wdt_enable(void) |
1da177e4 | 42 | { |
640b4f68 | 43 | spin_lock(&wdt_lock); |
1da177e4 LT |
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); | |
640b4f68 | 48 | spin_unlock(&wdt_lock); |
1da177e4 LT |
49 | } |
50 | ||
640b4f68 | 51 | static void wdt_disable(void) |
1da177e4 | 52 | { |
640b4f68 | 53 | spin_lock(&wdt_lock); |
1da177e4 | 54 | ixp2000_reg_write(IXP2000_T4_CTL, 0); |
640b4f68 | 55 | spin_unlock(&wdt_lock); |
1da177e4 LT |
56 | } |
57 | ||
640b4f68 | 58 | static void wdt_keepalive(void) |
1da177e4 | 59 | { |
640b4f68 | 60 | spin_lock(&wdt_lock); |
1da177e4 | 61 | ixp2000_reg_write(IXP2000_T4_CLD, heartbeat * wdt_tick_rate); |
640b4f68 | 62 | spin_unlock(&wdt_lock); |
1da177e4 LT |
63 | } |
64 | ||
640b4f68 | 65 | static int ixp2000_wdt_open(struct inode *inode, struct file *file) |
1da177e4 LT |
66 | { |
67 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
68 | return -EBUSY; | |
69 | ||
70 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
71 | ||
72 | wdt_enable(); | |
73 | ||
74 | return nonseekable_open(inode, file); | |
75 | } | |
76 | ||
640b4f68 AC |
77 | static ssize_t ixp2000_wdt_write(struct file *file, const char *data, |
78 | size_t len, loff_t *ppos) | |
1da177e4 LT |
79 | { |
80 | if (len) { | |
81 | if (!nowayout) { | |
82 | size_t i; | |
83 | ||
84 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
85 | ||
86 | for (i = 0; i != len; i++) { | |
87 | char c; | |
88 | ||
89 | if (get_user(c, data + i)) | |
90 | return -EFAULT; | |
91 | if (c == 'V') | |
92 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
93 | } | |
94 | } | |
95 | wdt_keepalive(); | |
96 | } | |
97 | ||
98 | return len; | |
99 | } | |
100 | ||
101 | ||
102 | static struct watchdog_info ident = { | |
103 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | | |
104 | WDIOF_KEEPALIVEPING, | |
105 | .identity = "IXP2000 Watchdog", | |
106 | }; | |
107 | ||
640b4f68 AC |
108 | static long ixp2000_wdt_ioctl(struct file *file, unsigned int cmd, |
109 | unsigned long arg) | |
1da177e4 | 110 | { |
795b89d2 | 111 | int ret = -ENOTTY; |
1da177e4 LT |
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 | ||
0c06090c WVS |
128 | case WDIOC_KEEPALIVE: |
129 | wdt_enable(); | |
130 | ret = 0; | |
131 | break; | |
132 | ||
1da177e4 LT |
133 | case WDIOC_SETTIMEOUT: |
134 | ret = get_user(time, (int *)arg); | |
135 | if (ret) | |
136 | break; | |
137 | ||
138 | if (time <= 0 || time > 60) { | |
139 | ret = -EINVAL; | |
140 | break; | |
141 | } | |
142 | ||
143 | heartbeat = time; | |
144 | wdt_keepalive(); | |
145 | /* Fall through */ | |
146 | ||
147 | case WDIOC_GETTIMEOUT: | |
148 | ret = put_user(heartbeat, (int *)arg); | |
149 | break; | |
1da177e4 LT |
150 | } |
151 | ||
152 | return ret; | |
153 | } | |
154 | ||
640b4f68 | 155 | static int ixp2000_wdt_release(struct inode *inode, struct file *file) |
1da177e4 | 156 | { |
640b4f68 | 157 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) |
1da177e4 | 158 | wdt_disable(); |
640b4f68 | 159 | else |
b36bbb6c | 160 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " |
1da177e4 | 161 | "timer will not stop\n"); |
1da177e4 LT |
162 | clear_bit(WDT_IN_USE, &wdt_status); |
163 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
164 | ||
165 | return 0; | |
166 | } | |
167 | ||
168 | ||
640b4f68 | 169 | static const struct file_operations ixp2000_wdt_fops = { |
1da177e4 LT |
170 | .owner = THIS_MODULE, |
171 | .llseek = no_llseek, | |
172 | .write = ixp2000_wdt_write, | |
640b4f68 | 173 | .unlocked_ioctl = ixp2000_wdt_ioctl, |
1da177e4 LT |
174 | .open = ixp2000_wdt_open, |
175 | .release = ixp2000_wdt_release, | |
176 | }; | |
177 | ||
640b4f68 | 178 | static struct miscdevice ixp2000_wdt_miscdev = { |
1da177e4 | 179 | .minor = WATCHDOG_MINOR, |
2dab3cab | 180 | .name = "watchdog", |
1da177e4 LT |
181 | .fops = &ixp2000_wdt_fops, |
182 | }; | |
183 | ||
184 | static int __init ixp2000_wdt_init(void) | |
185 | { | |
e4fe1981 LB |
186 | if ((*IXP2000_PRODUCT_ID & 0x001ffef0) == 0x00000000) { |
187 | printk(KERN_INFO "Unable to use IXP2000 watchdog due to IXP2800 erratum #25.\n"); | |
188 | return -EIO; | |
189 | } | |
e4fe1981 | 190 | wdt_tick_rate = (*IXP2000_T1_CLD * HZ) / 256; |
640b4f68 | 191 | spin_lock_init(&wdt_lock); |
1da177e4 LT |
192 | return misc_register(&ixp2000_wdt_miscdev); |
193 | } | |
194 | ||
195 | static void __exit ixp2000_wdt_exit(void) | |
196 | { | |
197 | misc_deregister(&ixp2000_wdt_miscdev); | |
198 | } | |
199 | ||
200 | module_init(ixp2000_wdt_init); | |
201 | module_exit(ixp2000_wdt_exit); | |
202 | ||
632155e6 | 203 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); |
1da177e4 LT |
204 | MODULE_DESCRIPTION("IXP2000 Network Processor Watchdog"); |
205 | ||
206 | module_param(heartbeat, int, 0); | |
207 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | |
208 | ||
209 | module_param(nowayout, int, 0); | |
210 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | |
211 | ||
212 | MODULE_LICENSE("GPL"); | |
213 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
214 |