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1da177e4 LT |
1 | /* |
2 | * drivers/watchdog/ixp4xx_wdt.c | |
3 | * | |
4 | * Watchdog driver for Intel IXP4xx network processors | |
5 | * | |
6 | * Author: Deepak Saxena <dsaxena@plexity.net> | |
7 | * | |
8 | * Copyright 2004 (c) MontaVista, Software, Inc. | |
9 | * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu> | |
10 | * | |
11 | * This file is licensed under the terms of the GNU General Public | |
12 | * License version 2. This program is licensed "as is" without any | |
13 | * warranty of any kind, whether express or implied. | |
14 | */ | |
15 | ||
16 | #include <linux/config.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/moduleparam.h> | |
19 | #include <linux/types.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/miscdevice.h> | |
23 | #include <linux/watchdog.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/bitops.h> | |
26 | ||
27 | #include <asm/hardware.h> | |
28 | #include <asm/uaccess.h> | |
29 | ||
4bfdf378 | 30 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
31 | static int heartbeat = 60; /* (secs) Default is 1 minute */ |
32 | static unsigned long wdt_status; | |
33 | static unsigned long boot_status; | |
34 | ||
35 | #define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL) | |
36 | ||
37 | #define WDT_IN_USE 0 | |
38 | #define WDT_OK_TO_CLOSE 1 | |
39 | ||
40 | static void | |
41 | wdt_enable(void) | |
42 | { | |
43 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; | |
44 | *IXP4XX_OSWE = 0; | |
45 | *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat; | |
46 | *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE; | |
47 | *IXP4XX_OSWK = 0; | |
48 | } | |
49 | ||
50 | static void | |
51 | wdt_disable(void) | |
52 | { | |
53 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; | |
54 | *IXP4XX_OSWE = 0; | |
55 | *IXP4XX_OSWK = 0; | |
56 | } | |
57 | ||
58 | static int | |
59 | ixp4xx_wdt_open(struct inode *inode, struct file *file) | |
60 | { | |
61 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
62 | return -EBUSY; | |
63 | ||
64 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
65 | ||
66 | wdt_enable(); | |
67 | ||
68 | return nonseekable_open(inode, file); | |
69 | } | |
70 | ||
71 | static ssize_t | |
72 | ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) | |
73 | { | |
74 | if (len) { | |
75 | if (!nowayout) { | |
76 | size_t i; | |
77 | ||
78 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
79 | ||
80 | for (i = 0; i != len; i++) { | |
81 | char c; | |
82 | ||
83 | if (get_user(c, data + i)) | |
84 | return -EFAULT; | |
85 | if (c == 'V') | |
86 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
87 | } | |
88 | } | |
89 | wdt_enable(); | |
90 | } | |
91 | ||
92 | return len; | |
93 | } | |
94 | ||
95 | static struct watchdog_info ident = { | |
96 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | | |
97 | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
98 | .identity = "IXP4xx Watchdog", | |
99 | }; | |
100 | ||
101 | ||
102 | static int | |
103 | ixp4xx_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
104 | unsigned long arg) | |
105 | { | |
106 | int ret = -ENOIOCTLCMD; | |
107 | int time; | |
108 | ||
109 | switch (cmd) { | |
110 | case WDIOC_GETSUPPORT: | |
111 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
112 | sizeof(ident)) ? -EFAULT : 0; | |
113 | break; | |
114 | ||
115 | case WDIOC_GETSTATUS: | |
116 | ret = put_user(0, (int *)arg); | |
117 | break; | |
118 | ||
119 | case WDIOC_GETBOOTSTATUS: | |
120 | ret = put_user(boot_status, (int *)arg); | |
121 | break; | |
122 | ||
123 | case WDIOC_SETTIMEOUT: | |
124 | ret = get_user(time, (int *)arg); | |
125 | if (ret) | |
126 | break; | |
127 | ||
128 | if (time <= 0 || time > 60) { | |
129 | ret = -EINVAL; | |
130 | break; | |
131 | } | |
132 | ||
133 | heartbeat = time; | |
134 | wdt_enable(); | |
135 | /* Fall through */ | |
136 | ||
137 | case WDIOC_GETTIMEOUT: | |
138 | ret = put_user(heartbeat, (int *)arg); | |
139 | break; | |
140 | ||
141 | case WDIOC_KEEPALIVE: | |
142 | wdt_enable(); | |
143 | ret = 0; | |
144 | break; | |
145 | } | |
146 | return ret; | |
147 | } | |
148 | ||
149 | static int | |
150 | ixp4xx_wdt_release(struct inode *inode, struct file *file) | |
151 | { | |
152 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) { | |
153 | wdt_disable(); | |
154 | } else { | |
b36bbb6c | 155 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " |
1da177e4 LT |
156 | "timer will not stop\n"); |
157 | } | |
158 | ||
159 | clear_bit(WDT_IN_USE, &wdt_status); | |
160 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | ||
166 | static struct file_operations ixp4xx_wdt_fops = | |
167 | { | |
168 | .owner = THIS_MODULE, | |
169 | .llseek = no_llseek, | |
170 | .write = ixp4xx_wdt_write, | |
171 | .ioctl = ixp4xx_wdt_ioctl, | |
172 | .open = ixp4xx_wdt_open, | |
173 | .release = ixp4xx_wdt_release, | |
174 | }; | |
175 | ||
176 | static struct miscdevice ixp4xx_wdt_miscdev = | |
177 | { | |
178 | .minor = WATCHDOG_MINOR, | |
2dab3cab | 179 | .name = "watchdog", |
1da177e4 LT |
180 | .fops = &ixp4xx_wdt_fops, |
181 | }; | |
182 | ||
183 | static int __init ixp4xx_wdt_init(void) | |
184 | { | |
185 | int ret; | |
186 | unsigned long processor_id; | |
187 | ||
188 | asm("mrc p15, 0, %0, cr0, cr0, 0;" : "=r"(processor_id) :); | |
189 | if (!(processor_id & 0xf)) { | |
190 | printk("IXP4XXX Watchdog: Rev. A0 CPU detected - " | |
191 | "watchdog disabled\n"); | |
192 | ||
193 | return -ENODEV; | |
194 | } | |
195 | ||
196 | ret = misc_register(&ixp4xx_wdt_miscdev); | |
197 | if (ret == 0) | |
198 | printk("IXP4xx Watchdog Timer: heartbeat %d sec\n", heartbeat); | |
199 | ||
200 | boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ? | |
201 | WDIOF_CARDRESET : 0; | |
202 | ||
203 | return ret; | |
204 | } | |
205 | ||
206 | static void __exit ixp4xx_wdt_exit(void) | |
207 | { | |
208 | misc_deregister(&ixp4xx_wdt_miscdev); | |
209 | } | |
210 | ||
211 | ||
212 | module_init(ixp4xx_wdt_init); | |
213 | module_exit(ixp4xx_wdt_exit); | |
214 | ||
215 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); | |
216 | MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog"); | |
217 | ||
218 | module_param(heartbeat, int, 0); | |
219 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); | |
220 | ||
221 | module_param(nowayout, int, 0); | |
222 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); | |
223 | ||
224 | MODULE_LICENSE("GPL"); | |
225 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
226 |