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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>
28
29#ifdef CONFIG_ARCH_PXA
30#include <asm/arch/pxa-regs.h>
31#endif
32
33#include <asm/hardware.h>
34#include <asm/bitops.h>
35#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{
48 nonseekable_open(inode, file);
49 if (test_and_set_bit(1,&sa1100wdt_users))
50 return -EBUSY;
51
52 /* Activate SA1100 Watchdog timer */
53 OSMR3 = OSCR + pre_margin;
54 OSSR = OSSR_M3;
55 OWER = OWER_WME;
56 OIER |= OIER_E3;
57 return 0;
58}
59
60/*
Ian Campbell9bbd0372005-08-03 20:34:52 +010061 * The watchdog cannot be disabled.
62 *
63 * Previous comments suggested that turning off the interrupt by
64 * clearing OIER[E3] would prevent the watchdog timing out but this
65 * does not appear to be true (at least on the PXA255).
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 */
67static int sa1100dog_release(struct inode *inode, struct file *file)
68{
Ian Campbell9bbd0372005-08-03 20:34:52 +010069 printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
71 clear_bit(1, &sa1100wdt_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 return 0;
74}
75
Ian Campbella0734042005-11-02 08:56:49 +000076static ssize_t sa1100dog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077{
Ian Campbell9bbd0372005-08-03 20:34:52 +010078 if (len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 /* Refresh OSMR3 timer. */
80 OSMR3 = OSCR + pre_margin;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
82 return len;
83}
84
85static struct watchdog_info ident = {
Ian Campbell9bbd0372005-08-03 20:34:52 +010086 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
87 .identity = "SA1100/PXA255 Watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -070088};
89
90static int sa1100dog_ioctl(struct inode *inode, struct file *file,
91 unsigned int cmd, unsigned long arg)
92{
93 int ret = -ENOIOCTLCMD;
94 int time;
Ian Campbell3a69e572005-11-07 10:21:24 +000095 void __user *argp = (void __user *)arg;
96 int __user *p = argp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98 switch (cmd) {
99 case WDIOC_GETSUPPORT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000100 ret = copy_to_user(argp, &ident,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 sizeof(ident)) ? -EFAULT : 0;
102 break;
103
104 case WDIOC_GETSTATUS:
Ian Campbell3a69e572005-11-07 10:21:24 +0000105 ret = put_user(0, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 break;
107
108 case WDIOC_GETBOOTSTATUS:
Ian Campbell3a69e572005-11-07 10:21:24 +0000109 ret = put_user(boot_status, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 break;
111
112 case WDIOC_SETTIMEOUT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000113 ret = get_user(time, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 if (ret)
115 break;
116
117 if (time <= 0 || time > 255) {
118 ret = -EINVAL;
119 break;
120 }
121
122 pre_margin = OSCR_FREQ * time;
123 OSMR3 = OSCR + pre_margin;
124 /*fall through*/
125
126 case WDIOC_GETTIMEOUT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000127 ret = put_user(pre_margin / OSCR_FREQ, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 break;
129
130 case WDIOC_KEEPALIVE:
131 OSMR3 = OSCR + pre_margin;
132 ret = 0;
133 break;
134 }
135 return ret;
136}
137
Arjan van de Ven62322d22006-07-03 00:24:21 -0700138static const struct file_operations sa1100dog_fops =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 .owner = THIS_MODULE,
141 .llseek = no_llseek,
142 .write = sa1100dog_write,
143 .ioctl = sa1100dog_ioctl,
144 .open = sa1100dog_open,
145 .release = sa1100dog_release,
146};
147
148static struct miscdevice sa1100dog_miscdev =
149{
150 .minor = WATCHDOG_MINOR,
Ian Campbell9bbd0372005-08-03 20:34:52 +0100151 .name = "watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 .fops = &sa1100dog_fops,
153};
154
155static int margin __initdata = 60; /* (secs) Default is 1 minute */
156
157static int __init sa1100dog_init(void)
158{
159 int ret;
160
161 /*
162 * Read the reset status, and save it for later. If
163 * we suspend, RCSR will be cleared, and the watchdog
164 * reset reason will be lost.
165 */
166 boot_status = (RCSR & RCSR_WDR) ? WDIOF_CARDRESET : 0;
167 pre_margin = OSCR_FREQ * margin;
168
169 ret = misc_register(&sa1100dog_miscdev);
170 if (ret == 0)
171 printk("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
172 margin);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 return ret;
174}
175
176static void __exit sa1100dog_exit(void)
177{
178 misc_deregister(&sa1100dog_miscdev);
179}
180
181module_init(sa1100dog_init);
182module_exit(sa1100dog_exit);
183
184MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
185MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
186
187module_param(margin, int, 0);
188MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190MODULE_LICENSE("GPL");
191MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);