Merge ../linux-2.6 by hand
[linux-2.6] / drivers / char / watchdog / mpc8xx_wdt.c
1 /*
2  * mpc8xx_wdt.c - MPC8xx watchdog userspace interface
3  *
4  * Author: Florian Schirmer <jolt@tuxbox.org>
5  *
6  * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
7  * the terms of the GNU General Public License version 2. This program
8  * is licensed "as is" without any warranty of any kind, whether express
9  * or implied.
10  */
11
12 #include <linux/config.h>
13 #include <linux/fs.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/miscdevice.h>
17 #include <linux/module.h>
18 #include <linux/watchdog.h>
19 #include <asm/8xx_immap.h>
20 #include <asm/uaccess.h>
21 #include <syslib/m8xx_wdt.h>
22
23 static unsigned long wdt_opened;
24 static int wdt_status;
25
26 static void mpc8xx_wdt_handler_disable(void)
27 {
28         volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
29
30         imap->im_sit.sit_piscr &= ~(PISCR_PIE | PISCR_PTE);
31
32         printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
33 }
34
35 static void mpc8xx_wdt_handler_enable(void)
36 {
37         volatile immap_t *imap = (volatile immap_t *)IMAP_ADDR;
38
39         imap->im_sit.sit_piscr |= PISCR_PIE | PISCR_PTE;
40
41         printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
42 }
43
44 static int mpc8xx_wdt_open(struct inode *inode, struct file *file)
45 {
46         if (test_and_set_bit(0, &wdt_opened))
47                 return -EBUSY;
48
49         m8xx_wdt_reset();
50         mpc8xx_wdt_handler_disable();
51
52         return 0;
53 }
54
55 static int mpc8xx_wdt_release(struct inode *inode, struct file *file)
56 {
57         m8xx_wdt_reset();
58
59 #if !defined(CONFIG_WATCHDOG_NOWAYOUT)
60         mpc8xx_wdt_handler_enable();
61 #endif
62
63         clear_bit(0, &wdt_opened);
64
65         return 0;
66 }
67
68 static ssize_t mpc8xx_wdt_write(struct file *file, const char *data, size_t len,
69                                 loff_t * ppos)
70 {
71         if (ppos != &file->f_pos)
72                 return -ESPIPE;
73
74         if (len)
75                 m8xx_wdt_reset();
76
77         return len;
78 }
79
80 static int mpc8xx_wdt_ioctl(struct inode *inode, struct file *file,
81                             unsigned int cmd, unsigned long arg)
82 {
83         int timeout;
84         static struct watchdog_info info = {
85                 .options = WDIOF_KEEPALIVEPING,
86                 .firmware_version = 0,
87                 .identity = "MPC8xx watchdog",
88         };
89
90         switch (cmd) {
91         case WDIOC_GETSUPPORT:
92                 if (copy_to_user((void *)arg, &info, sizeof(info)))
93                         return -EFAULT;
94                 break;
95
96         case WDIOC_GETSTATUS:
97         case WDIOC_GETBOOTSTATUS:
98                 if (put_user(wdt_status, (int *)arg))
99                         return -EFAULT;
100                 wdt_status &= ~WDIOF_KEEPALIVEPING;
101                 break;
102
103         case WDIOC_GETTEMP:
104                 return -EOPNOTSUPP;
105
106         case WDIOC_SETOPTIONS:
107                 return -EOPNOTSUPP;
108
109         case WDIOC_KEEPALIVE:
110                 m8xx_wdt_reset();
111                 wdt_status |= WDIOF_KEEPALIVEPING;
112                 break;
113
114         case WDIOC_SETTIMEOUT:
115                 return -EOPNOTSUPP;
116
117         case WDIOC_GETTIMEOUT:
118                 timeout = m8xx_wdt_get_timeout();
119                 if (put_user(timeout, (int *)arg))
120                         return -EFAULT;
121                 break;
122
123         default:
124                 return -ENOIOCTLCMD;
125         }
126
127         return 0;
128 }
129
130 static struct file_operations mpc8xx_wdt_fops = {
131         .owner = THIS_MODULE,
132         .llseek = no_llseek,
133         .write = mpc8xx_wdt_write,
134         .ioctl = mpc8xx_wdt_ioctl,
135         .open = mpc8xx_wdt_open,
136         .release = mpc8xx_wdt_release,
137 };
138
139 static struct miscdevice mpc8xx_wdt_miscdev = {
140         .minor = WATCHDOG_MINOR,
141         .name = "watchdog",
142         .fops = &mpc8xx_wdt_fops,
143 };
144
145 static int __init mpc8xx_wdt_init(void)
146 {
147         return misc_register(&mpc8xx_wdt_miscdev);
148 }
149
150 static void __exit mpc8xx_wdt_exit(void)
151 {
152         misc_deregister(&mpc8xx_wdt_miscdev);
153
154         m8xx_wdt_reset();
155         mpc8xx_wdt_handler_enable();
156 }
157
158 module_init(mpc8xx_wdt_init);
159 module_exit(mpc8xx_wdt_exit);
160
161 MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
162 MODULE_DESCRIPTION("MPC8xx watchdog driver");
163 MODULE_LICENSE("GPL");
164 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);