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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Watchdog driver for the SA11x0/PXA2xx
3 *
4 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
5 * Based on SoftDog driver by Alan Cox <alan@redhat.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Neither Oleg Drokin nor iXcelerator.com admit liability nor provide
13 * warranty for any of this software. This material is provided
14 * "AS-IS" and at no charge.
15 *
16 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
17 *
18 * 27/11/2000 Initial release
19 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/module.h>
21#include <linux/moduleparam.h>
22#include <linux/types.h>
23#include <linux/kernel.h>
24#include <linux/fs.h>
25#include <linux/miscdevice.h>
26#include <linux/watchdog.h>
27#include <linux/init.h>
Jiri Slaby1977f032007-10-18 23:40:25 -070028#include <linux/bitops.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30#ifdef CONFIG_ARCH_PXA
31#include <asm/arch/pxa-regs.h>
32#endif
33
34#include <asm/hardware.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <asm/uaccess.h>
36
37#define OSCR_FREQ CLOCK_TICK_RATE
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39static unsigned long sa1100wdt_users;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040static int pre_margin;
41static int boot_status;
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
43/*
44 * Allow only one person to hold it open
45 */
46static int sa1100dog_open(struct inode *inode, struct file *file)
47{
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 if (test_and_set_bit(1,&sa1100wdt_users))
49 return -EBUSY;
50
51 /* Activate SA1100 Watchdog timer */
52 OSMR3 = OSCR + pre_margin;
53 OSSR = OSSR_M3;
54 OWER = OWER_WME;
55 OIER |= OIER_E3;
Wim Van Sebroeck6abe78b2007-07-24 21:38:37 +000056 return nonseekable_open(inode, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
59/*
Ian Campbell9bbd0372005-08-03 20:34:52 +010060 * The watchdog cannot be disabled.
61 *
62 * Previous comments suggested that turning off the interrupt by
63 * clearing OIER[E3] would prevent the watchdog timing out but this
64 * does not appear to be true (at least on the PXA255).
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 */
66static int sa1100dog_release(struct inode *inode, struct file *file)
67{
Ian Campbell9bbd0372005-08-03 20:34:52 +010068 printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
70 clear_bit(1, &sa1100wdt_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72 return 0;
73}
74
Ian Campbella0734042005-11-02 08:56:49 +000075static ssize_t sa1100dog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -070076{
Ian Campbell9bbd0372005-08-03 20:34:52 +010077 if (len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 /* Refresh OSMR3 timer. */
79 OSMR3 = OSCR + pre_margin;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81 return len;
82}
83
84static struct watchdog_info ident = {
Ian Campbell9bbd0372005-08-03 20:34:52 +010085 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
86 .identity = "SA1100/PXA255 Watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -070087};
88
89static int sa1100dog_ioctl(struct inode *inode, struct file *file,
90 unsigned int cmd, unsigned long arg)
91{
Samuel Tardieu795b89d2006-09-09 17:34:31 +020092 int ret = -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 int time;
Ian Campbell3a69e572005-11-07 10:21:24 +000094 void __user *argp = (void __user *)arg;
95 int __user *p = argp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97 switch (cmd) {
98 case WDIOC_GETSUPPORT:
Ian Campbell3a69e572005-11-07 10:21:24 +000099 ret = copy_to_user(argp, &ident,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 sizeof(ident)) ? -EFAULT : 0;
101 break;
102
103 case WDIOC_GETSTATUS:
Ian Campbell3a69e572005-11-07 10:21:24 +0000104 ret = put_user(0, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 break;
106
107 case WDIOC_GETBOOTSTATUS:
Ian Campbell3a69e572005-11-07 10:21:24 +0000108 ret = put_user(boot_status, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 break;
110
111 case WDIOC_SETTIMEOUT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000112 ret = get_user(time, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 if (ret)
114 break;
115
116 if (time <= 0 || time > 255) {
117 ret = -EINVAL;
118 break;
119 }
120
121 pre_margin = OSCR_FREQ * time;
122 OSMR3 = OSCR + pre_margin;
123 /*fall through*/
124
125 case WDIOC_GETTIMEOUT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000126 ret = put_user(pre_margin / OSCR_FREQ, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 break;
128
129 case WDIOC_KEEPALIVE:
130 OSMR3 = OSCR + pre_margin;
131 ret = 0;
132 break;
133 }
134 return ret;
135}
136
Arjan van de Ven62322d22006-07-03 00:24:21 -0700137static const struct file_operations sa1100dog_fops =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{
139 .owner = THIS_MODULE,
140 .llseek = no_llseek,
141 .write = sa1100dog_write,
142 .ioctl = sa1100dog_ioctl,
143 .open = sa1100dog_open,
144 .release = sa1100dog_release,
145};
146
147static struct miscdevice sa1100dog_miscdev =
148{
149 .minor = WATCHDOG_MINOR,
Ian Campbell9bbd0372005-08-03 20:34:52 +0100150 .name = "watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 .fops = &sa1100dog_fops,
152};
153
154static int margin __initdata = 60; /* (secs) Default is 1 minute */
155
156static int __init sa1100dog_init(void)
157{
158 int ret;
159
160 /*
161 * Read the reset status, and save it for later. If
162 * we suspend, RCSR will be cleared, and the watchdog
163 * reset reason will be lost.
164 */
165 boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0;
166 pre_margin = OSCR_FREQ * margin;
167
168 ret = misc_register(&sa1100dog_miscdev);
169 if (ret == 0)
170 printk("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
171 margin);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 return ret;
173}
174
175static void __exit sa1100dog_exit(void)
176{
177 misc_deregister(&sa1100dog_miscdev);
178}
179
180module_init(sa1100dog_init);
181module_exit(sa1100dog_exit);
182
183MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
184MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
185
186module_param(margin, int, 0);
187MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189MODULE_LICENSE("GPL");
190MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);