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 <asm/io.h>
22 #include <syslib/m8xx_wdt.h>
23
24 static unsigned long wdt_opened;
25 static int wdt_status;
26
27 static void mpc8xx_wdt_handler_disable(void)
28 {
29 volatile uint __iomem *piscr;
30 piscr = (uint *)&((immap_t*)IMAP_ADDR)->im_sit.sit_piscr;
31
32 if (!m8xx_has_internal_rtc)
33 m8xx_wdt_stop_timer();
34 else
35 out_be32(piscr, in_be32(piscr) & ~(PISCR_PIE | PISCR_PTE));
36
37 printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
38 }
39
40 static void mpc8xx_wdt_handler_enable(void)
41 {
42 volatile uint __iomem *piscr;
43 piscr = (uint *)&((immap_t*)IMAP_ADDR)->im_sit.sit_piscr;
44
45 if (!m8xx_has_internal_rtc)
46 m8xx_wdt_install_timer();
47 else
48 out_be32(piscr, in_be32(piscr) | PISCR_PIE | PISCR_PTE);
49
50 printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
51 }
52
53 static int mpc8xx_wdt_open(struct inode *inode, struct file *file)
54 {
55 if (test_and_set_bit(0, &wdt_opened))
56 return -EBUSY;
57
58 m8xx_wdt_reset();
59 mpc8xx_wdt_handler_disable();
60
61 return 0;
62 }
63
64 static int mpc8xx_wdt_release(struct inode *inode, struct file *file)
65 {
66 m8xx_wdt_reset();
67
68 #if !defined(CONFIG_WATCHDOG_NOWAYOUT)
69 mpc8xx_wdt_handler_enable();
70 #endif
71
72 clear_bit(0, &wdt_opened);
73
74 return 0;
75 }
76
77 static ssize_t mpc8xx_wdt_write(struct file *file, const char *data, size_t len,
78 loff_t * ppos)
79 {
80 if (len)
81 m8xx_wdt_reset();
82
83 return len;
84 }
85
86 static int mpc8xx_wdt_ioctl(struct inode *inode, struct file *file,
87 unsigned int cmd, unsigned long arg)
88 {
89 int timeout;
90 static struct watchdog_info info = {
91 .options = WDIOF_KEEPALIVEPING,
92 .firmware_version = 0,
93 .identity = "MPC8xx watchdog",
94 };
95
96 switch (cmd) {
97 case WDIOC_GETSUPPORT:
98 if (copy_to_user((void *)arg, &info, sizeof(info)))
99 return -EFAULT;
100 break;
101
102 case WDIOC_GETSTATUS:
103 case WDIOC_GETBOOTSTATUS:
104 if (put_user(wdt_status, (int *)arg))
105 return -EFAULT;
106 wdt_status &= ~WDIOF_KEEPALIVEPING;
107 break;
108
109 case WDIOC_GETTEMP:
110 return -EOPNOTSUPP;
111
112 case WDIOC_SETOPTIONS:
113 return -EOPNOTSUPP;
114
115 case WDIOC_KEEPALIVE:
116 m8xx_wdt_reset();
117 wdt_status |= WDIOF_KEEPALIVEPING;
118 break;
119
120 case WDIOC_SETTIMEOUT:
121 return -EOPNOTSUPP;
122
123 case WDIOC_GETTIMEOUT:
124 timeout = m8xx_wdt_get_timeout();
125 if (put_user(timeout, (int *)arg))
126 return -EFAULT;
127 break;
128
129 default:
130 return -ENOIOCTLCMD;
131 }
132
133 return 0;
134 }
135
136 static struct file_operations mpc8xx_wdt_fops = {
137 .owner = THIS_MODULE,
138 .llseek = no_llseek,
139 .write = mpc8xx_wdt_write,
140 .ioctl = mpc8xx_wdt_ioctl,
141 .open = mpc8xx_wdt_open,
142 .release = mpc8xx_wdt_release,
143 };
144
145 static struct miscdevice mpc8xx_wdt_miscdev = {
146 .minor = WATCHDOG_MINOR,
147 .name = "watchdog",
148 .fops = &mpc8xx_wdt_fops,
149 };
150
151 static int __init mpc8xx_wdt_init(void)
152 {
153 return misc_register(&mpc8xx_wdt_miscdev);
154 }
155
156 static void __exit mpc8xx_wdt_exit(void)
157 {
158 misc_deregister(&mpc8xx_wdt_miscdev);
159
160 m8xx_wdt_reset();
161 mpc8xx_wdt_handler_enable();
162 }
163
164 module_init(mpc8xx_wdt_init);
165 module_exit(mpc8xx_wdt_exit);
166
167 MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
168 MODULE_DESCRIPTION("MPC8xx watchdog driver");
169 MODULE_LICENSE("GPL");
170 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
171
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