[atheros]: move files for kernel 2.6.26 to a special directory.
[openwrt/svn-archive/archive.git] / target / linux / atheros / files-2.6.26 / drivers / watchdog / ar2315-wtd.c
1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
15 *
16 * Copyright (C) 2008 John Crispin <blogic@openwrt.org>
17 * Based on EP93xx and ifxmips wdt driver
18 */
19
20 #include <linux/interrupt.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/types.h>
24 #include <linux/miscdevice.h>
25 #include <linux/watchdog.h>
26 #include <linux/fs.h>
27 #include <linux/ioport.h>
28 #include <linux/notifier.h>
29 #include <linux/reboot.h>
30 #include <linux/init.h>
31 #include <linux/platform_device.h>
32
33 #include <asm/io.h>
34 #include <asm/uaccess.h>
35 #include <asm/system.h>
36 #include <asm/addrspace.h>
37 #include <ar531x.h>
38
39 #define CLOCK_RATE 40000000
40 #define HEARTBEAT(x) (x < 1 || x > 90)?(20):(x)
41
42 static int wdt_timeout = 20;
43 static int started = 0;
44 static int in_use = 0;
45
46 static void
47 ar2315_wdt_enable(void)
48 {
49 sysRegWrite(AR5315_WD, wdt_timeout * CLOCK_RATE);
50 sysRegWrite(AR5315_ISR, 0x80);
51 }
52
53 static ssize_t
54 ar2315_wdt_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
55 {
56 if(len)
57 ar2315_wdt_enable();
58 return len;
59 }
60
61 static int
62 ar2315_wdt_open(struct inode *inode, struct file *file)
63 {
64 if(in_use)
65 return -EBUSY;
66 ar2315_wdt_enable();
67 in_use = started = 1;
68 return nonseekable_open(inode, file);
69 }
70
71 static int
72 ar2315_wdt_release(struct inode *inode, struct file *file)
73 {
74 in_use = 0;
75 return 0;
76 }
77
78 static irqreturn_t
79 ar2315_wdt_interrupt(int irq, void *dev_id)
80 {
81 if(started)
82 {
83 printk(KERN_CRIT "watchdog expired, rebooting system\n");
84 emergency_restart();
85 } else {
86 sysRegWrite(AR5315_WDC, 0);
87 sysRegWrite(AR5315_WD, 0);
88 sysRegWrite(AR5315_ISR, 0x80);
89 }
90 return IRQ_HANDLED;
91 }
92
93 static struct watchdog_info ident = {
94 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
95 .identity = "ar2315 Watchdog",
96 };
97
98 static int
99 ar2315_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
100 {
101 int new_wdt_timeout;
102 int ret = -ENOIOCTLCMD;
103
104 switch(cmd)
105 {
106 case WDIOC_GETSUPPORT:
107 ret = copy_to_user((struct watchdog_info __user *)arg, &ident, sizeof(ident)) ? -EFAULT : 0;
108 break;
109
110 case WDIOC_KEEPALIVE:
111 ar2315_wdt_enable();
112 ret = 0;
113 break;
114
115 case WDIOC_SETTIMEOUT:
116 if((ret = get_user(new_wdt_timeout, (int __user *)arg)))
117 break;
118 wdt_timeout = HEARTBEAT(new_wdt_timeout);
119 ar2315_wdt_enable();
120 break;
121
122 case WDIOC_GETTIMEOUT:
123 ret = put_user(wdt_timeout, (int __user *)arg);
124 break;
125 }
126 return ret;
127 }
128
129 static struct file_operations ar2315_wdt_fops = {
130 .owner = THIS_MODULE,
131 .llseek = no_llseek,
132 .write = ar2315_wdt_write,
133 .ioctl = ar2315_wdt_ioctl,
134 .open = ar2315_wdt_open,
135 .release = ar2315_wdt_release,
136 };
137
138 static struct miscdevice ar2315_wdt_miscdev = {
139 .minor = WATCHDOG_MINOR,
140 .name = "watchdog",
141 .fops = &ar2315_wdt_fops,
142 };
143
144 static int
145 ar2315_wdt_probe(struct platform_device *dev)
146 {
147 int ret = 0;
148
149 ar2315_wdt_enable();
150 ret = request_irq(AR531X_MISC_IRQ_WATCHDOG, ar2315_wdt_interrupt, IRQF_DISABLED, "ar2315_wdt", NULL);
151 if(ret)
152 {
153 printk(KERN_ERR "ar2315wdt: failed to register inetrrupt\n");
154 goto out;
155 }
156
157 ret = misc_register(&ar2315_wdt_miscdev);
158 if(ret)
159 printk(KERN_ERR "ar2315wdt: failed to register miscdev\n");
160
161 out:
162 return ret;
163 }
164
165 static int
166 ar2315_wdt_remove(struct platform_device *dev)
167 {
168 misc_deregister(&ar2315_wdt_miscdev);
169 free_irq(AR531X_MISC_IRQ_WATCHDOG, NULL);
170 return 0;
171 }
172
173 static struct platform_driver ar2315_wdt_driver = {
174 .probe = ar2315_wdt_probe,
175 .remove = ar2315_wdt_remove,
176 .driver = {
177 .name = "ar2315_wdt",
178 .owner = THIS_MODULE,
179 },
180 };
181
182 static int __init
183 init_ar2315_wdt(void)
184 {
185 int ret = platform_driver_register(&ar2315_wdt_driver);
186 if(ret)
187 printk(KERN_INFO "ar2315_wdt: error registering platfom driver!");
188 return ret;
189 }
190
191 static void __exit
192 exit_ar2315_wdt(void)
193 {
194 platform_driver_unregister(&ar2315_wdt_driver);
195 }
196
197 module_init(init_ar2315_wdt);
198 module_exit(exit_ar2315_wdt);