blob: 06553debc7bc5ae7c21eb86022bb4479b7391ebd [file] [log] [blame]
Calin A. Culianueed65652006-01-14 13:20:46 -08001/*
2 * SBC EPX C3 0.1 A Hardware Watchdog Device for the Winsystems EPX-C3
3 * single board computer
4 *
5 * (c) Copyright 2006 Calin A. Culianu <calin@ajvar.org>, All Rights
6 * Reserved.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
Alan Cox29fa0582008-10-27 15:17:56 +000013 * based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
Calin A. Culianueed65652006-01-14 13:20:46 -080014 */
15
16#include <linux/module.h>
17#include <linux/moduleparam.h>
Calin A. Culianueed65652006-01-14 13:20:46 -080018#include <linux/types.h>
19#include <linux/kernel.h>
20#include <linux/fs.h>
21#include <linux/mm.h>
22#include <linux/miscdevice.h>
23#include <linux/watchdog.h>
24#include <linux/notifier.h>
25#include <linux/reboot.h>
26#include <linux/init.h>
Alan Coxde6c6422006-02-03 03:03:58 -080027#include <linux/ioport.h>
Alan Coxf4f6f652008-05-19 14:08:27 +010028#include <linux/uaccess.h>
29#include <linux/io.h>
Calin A. Culianueed65652006-01-14 13:20:46 -080030
31#define PFX "epx_c3: "
32static int epx_c3_alive;
33
34#define WATCHDOG_TIMEOUT 1 /* 1 sec default timeout */
35
36static int nowayout = WATCHDOG_NOWAYOUT;
37module_param(nowayout, int, 0);
Wim Van Sebroeckbffda5c2007-01-27 20:54:24 +010038MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Calin A. Culianueed65652006-01-14 13:20:46 -080039
40#define EPXC3_WATCHDOG_CTL_REG 0x1ee /* write 1 to enable, 0 to disable */
41#define EPXC3_WATCHDOG_PET_REG 0x1ef /* write anything to pet once enabled */
42
43static void epx_c3_start(void)
44{
45 outb(1, EPXC3_WATCHDOG_CTL_REG);
46}
47
48static void epx_c3_stop(void)
49{
50
51 outb(0, EPXC3_WATCHDOG_CTL_REG);
52
53 printk(KERN_INFO PFX "Stopped watchdog timer.\n");
54}
55
56static void epx_c3_pet(void)
57{
58 outb(1, EPXC3_WATCHDOG_PET_REG);
59}
60
61/*
62 * Allow only one person to hold it open
63 */
64static int epx_c3_open(struct inode *inode, struct file *file)
65{
66 if (epx_c3_alive)
67 return -EBUSY;
68
69 if (nowayout)
70 __module_get(THIS_MODULE);
71
72 /* Activate timer */
73 epx_c3_start();
74 epx_c3_pet();
75
76 epx_c3_alive = 1;
77 printk(KERN_INFO "Started watchdog timer.\n");
78
79 return nonseekable_open(inode, file);
80}
81
82static int epx_c3_release(struct inode *inode, struct file *file)
83{
84 /* Shut off the timer.
85 * Lock it in if it's a module and we defined ...NOWAYOUT */
86 if (!nowayout)
87 epx_c3_stop(); /* Turn the WDT off */
88
89 epx_c3_alive = 0;
90
91 return 0;
92}
93
Al Viro73a09e62006-02-01 06:04:15 -050094static ssize_t epx_c3_write(struct file *file, const char __user *data,
Calin A. Culianueed65652006-01-14 13:20:46 -080095 size_t len, loff_t *ppos)
96{
97 /* Refresh the timer. */
98 if (len)
99 epx_c3_pet();
100 return len;
101}
102
Alan Coxf4f6f652008-05-19 14:08:27 +0100103static long epx_c3_ioctl(struct file *file, unsigned int cmd,
104 unsigned long arg)
Calin A. Culianueed65652006-01-14 13:20:46 -0800105{
106 int options, retval = -EINVAL;
Al Viro73a09e62006-02-01 06:04:15 -0500107 int __user *argp = (void __user *)arg;
Alan Coxf4f6f652008-05-19 14:08:27 +0100108 static const struct watchdog_info ident = {
Calin A. Culianueed65652006-01-14 13:20:46 -0800109 .options = WDIOF_KEEPALIVEPING |
110 WDIOF_MAGICCLOSE,
111 .firmware_version = 0,
112 .identity = "Winsystems EPX-C3 H/W Watchdog",
113 };
114
115 switch (cmd) {
116 case WDIOC_GETSUPPORT:
Al Viro73a09e62006-02-01 06:04:15 -0500117 if (copy_to_user(argp, &ident, sizeof(ident)))
Calin A. Culianueed65652006-01-14 13:20:46 -0800118 return -EFAULT;
119 return 0;
120 case WDIOC_GETSTATUS:
121 case WDIOC_GETBOOTSTATUS:
Al Viro73a09e62006-02-01 06:04:15 -0500122 return put_user(0, argp);
Al Viro73a09e62006-02-01 06:04:15 -0500123 case WDIOC_SETOPTIONS:
124 if (get_user(options, argp))
Calin A. Culianueed65652006-01-14 13:20:46 -0800125 return -EFAULT;
126
127 if (options & WDIOS_DISABLECARD) {
128 epx_c3_stop();
129 retval = 0;
130 }
131
132 if (options & WDIOS_ENABLECARD) {
133 epx_c3_start();
134 retval = 0;
135 }
136
137 return retval;
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000138 case WDIOC_KEEPALIVE:
139 epx_c3_pet();
140 return 0;
141 case WDIOC_GETTIMEOUT:
142 return put_user(WATCHDOG_TIMEOUT, argp);
Calin A. Culianueed65652006-01-14 13:20:46 -0800143 default:
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200144 return -ENOTTY;
Calin A. Culianueed65652006-01-14 13:20:46 -0800145 }
146}
147
148static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code,
149 void *unused)
150{
151 if (code == SYS_DOWN || code == SYS_HALT)
152 epx_c3_stop(); /* Turn the WDT off */
153
154 return NOTIFY_DONE;
155}
156
Arjan van de Ven62322d22006-07-03 00:24:21 -0700157static const struct file_operations epx_c3_fops = {
Calin A. Culianueed65652006-01-14 13:20:46 -0800158 .owner = THIS_MODULE,
159 .llseek = no_llseek,
160 .write = epx_c3_write,
Alan Coxf4f6f652008-05-19 14:08:27 +0100161 .unlocked_ioctl = epx_c3_ioctl,
Calin A. Culianueed65652006-01-14 13:20:46 -0800162 .open = epx_c3_open,
163 .release = epx_c3_release,
164};
165
166static struct miscdevice epx_c3_miscdev = {
167 .minor = WATCHDOG_MINOR,
168 .name = "watchdog",
169 .fops = &epx_c3_fops,
170};
171
172static struct notifier_block epx_c3_notifier = {
173 .notifier_call = epx_c3_notify_sys,
174};
175
176static const char banner[] __initdata =
177 KERN_INFO PFX "Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n";
178
179static int __init watchdog_init(void)
180{
181 int ret;
182
Alan Coxde6c6422006-02-03 03:03:58 -0800183 if (!request_region(EPXC3_WATCHDOG_CTL_REG, 2, "epxc3_watchdog"))
184 return -EBUSY;
185
Calin A. Culianueed65652006-01-14 13:20:46 -0800186 ret = register_reboot_notifier(&epx_c3_notifier);
187 if (ret) {
188 printk(KERN_ERR PFX "cannot register reboot notifier "
189 "(err=%d)\n", ret);
Alan Coxde6c6422006-02-03 03:03:58 -0800190 goto out;
Calin A. Culianueed65652006-01-14 13:20:46 -0800191 }
192
193 ret = misc_register(&epx_c3_miscdev);
194 if (ret) {
195 printk(KERN_ERR PFX "cannot register miscdev on minor=%d "
196 "(err=%d)\n", WATCHDOG_MINOR, ret);
197 unregister_reboot_notifier(&epx_c3_notifier);
Alan Coxde6c6422006-02-03 03:03:58 -0800198 goto out;
Calin A. Culianueed65652006-01-14 13:20:46 -0800199 }
200
201 printk(banner);
202
203 return 0;
Alan Coxde6c6422006-02-03 03:03:58 -0800204
205out:
206 release_region(EPXC3_WATCHDOG_CTL_REG, 2);
207 return ret;
Calin A. Culianueed65652006-01-14 13:20:46 -0800208}
209
210static void __exit watchdog_exit(void)
211{
212 misc_deregister(&epx_c3_miscdev);
213 unregister_reboot_notifier(&epx_c3_notifier);
Alan Coxde6c6422006-02-03 03:03:58 -0800214 release_region(EPXC3_WATCHDOG_CTL_REG, 2);
Calin A. Culianueed65652006-01-14 13:20:46 -0800215}
216
217module_init(watchdog_init);
218module_exit(watchdog_exit);
219
220MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>");
221MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC. Note that there is no way to probe for this device -- so only use it if you are *sure* you are runnning on this specific SBC system from Winsystems! It writes to IO ports 0x1ee and 0x1ef!");
222MODULE_LICENSE("GPL");
223MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);