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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>
Alan Cox29fa0582008-10-27 15:17:56 +00005 * Based on SoftDog driver by Alan Cox <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
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>
Alan Coxf19e0312008-05-19 14:08:05 +010029#include <linux/uaccess.h>
Russell King87c52572008-11-29 17:35:51 +000030#include <linux/timex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32#ifdef CONFIG_ARCH_PXA
Russell Kinga09e64f2008-08-05 16:14:15 +010033#include <mach/pxa-regs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#endif
35
Russell Kingafd2fc02008-08-07 11:05:25 +010036#include <mach/reset.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010037#include <mach/hardware.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
Eric Miao28a62382008-12-24 11:32:45 +080039static unsigned long oscr_freq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040static unsigned long sa1100wdt_users;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041static int pre_margin;
42static int boot_status;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
44/*
45 * Allow only one person to hold it open
46 */
47static int sa1100dog_open(struct inode *inode, struct file *file)
48{
Alan Coxf19e0312008-05-19 14:08:05 +010049 if (test_and_set_bit(1, &sa1100wdt_users))
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 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;
Wim Van Sebroeck6abe78b2007-07-24 21:38:37 +000057 return nonseekable_open(inode, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058}
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 clear_bit(1, &sa1100wdt_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return 0;
72}
73
Alan Coxf19e0312008-05-19 14:08:05 +010074static ssize_t sa1100dog_write(struct file *file, const char __user *data,
75 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 return len;
81}
82
Alan Coxf19e0312008-05-19 14:08:05 +010083static const struct watchdog_info ident = {
84 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
85 | WDIOF_KEEPALIVEPING,
Ian Campbell9bbd0372005-08-03 20:34:52 +010086 .identity = "SA1100/PXA255 Watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -070087};
88
Alan Coxf19e0312008-05-19 14:08:05 +010089static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
90 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
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
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000111 case WDIOC_KEEPALIVE:
112 OSMR3 = OSCR + pre_margin;
113 ret = 0;
114 break;
115
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 case WDIOC_SETTIMEOUT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000117 ret = get_user(time, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 if (ret)
119 break;
120
121 if (time <= 0 || time > 255) {
122 ret = -EINVAL;
123 break;
124 }
125
Eric Miao28a62382008-12-24 11:32:45 +0800126 pre_margin = oscr_freq * time;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 OSMR3 = OSCR + pre_margin;
128 /*fall through*/
129
130 case WDIOC_GETTIMEOUT:
Eric Miao28a62382008-12-24 11:32:45 +0800131 ret = put_user(pre_margin / oscr_freq, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 }
134 return ret;
135}
136
Alan Coxf19e0312008-05-19 14:08:05 +0100137static const struct file_operations sa1100dog_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 .owner = THIS_MODULE,
139 .llseek = no_llseek,
140 .write = sa1100dog_write,
Alan Coxf19e0312008-05-19 14:08:05 +0100141 .unlocked_ioctl = sa1100dog_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 .open = sa1100dog_open,
143 .release = sa1100dog_release,
144};
145
Alan Coxf19e0312008-05-19 14:08:05 +0100146static struct miscdevice sa1100dog_miscdev = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 .minor = WATCHDOG_MINOR,
Ian Campbell9bbd0372005-08-03 20:34:52 +0100148 .name = "watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 .fops = &sa1100dog_fops,
150};
151
152static int margin __initdata = 60; /* (secs) Default is 1 minute */
153
154static int __init sa1100dog_init(void)
155{
156 int ret;
157
Eric Miao28a62382008-12-24 11:32:45 +0800158 oscr_freq = get_clock_tick_rate();
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 /*
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 */
Eric Miao214c6a72008-07-29 14:39:34 +0800165 boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
166 WDIOF_CARDRESET : 0;
Eric Miao28a62382008-12-24 11:32:45 +0800167 pre_margin = oscr_freq * margin;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
169 ret = misc_register(&sa1100dog_miscdev);
170 if (ret == 0)
Alan Coxf19e0312008-05-19 14:08:05 +0100171 printk(KERN_INFO
172 "SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
173 margin);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 return ret;
175}
176
177static void __exit sa1100dog_exit(void)
178{
179 misc_deregister(&sa1100dog_miscdev);
180}
181
182module_init(sa1100dog_init);
183module_exit(sa1100dog_exit);
184
185MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
186MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
187
188module_param(margin, int, 0);
189MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
190
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191MODULE_LICENSE("GPL");
192MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);