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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Watchdog driver for the SA11x0/PXA2xx
3 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +00004 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
5 * 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 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000018 * 27/11/2000 Initial release
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 */
Joe Perches27c766a2012-02-15 15:06:19 -080020
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/module.h>
24#include <linux/moduleparam.h>
25#include <linux/types.h>
26#include <linux/kernel.h>
27#include <linux/fs.h>
28#include <linux/miscdevice.h>
29#include <linux/watchdog.h>
30#include <linux/init.h>
Rob Herring23019a72012-03-20 14:33:19 -050031#include <linux/io.h>
Jiri Slaby1977f032007-10-18 23:40:25 -070032#include <linux/bitops.h>
Alan Coxf19e0312008-05-19 14:08:05 +010033#include <linux/uaccess.h>
Russell King87c52572008-11-29 17:35:51 +000034#include <linux/timex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36#ifdef CONFIG_ARCH_PXA
Eric Miao5bf3df32009-01-20 11:04:16 +080037#include <mach/regs-ost.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#endif
39
Russell Kingafd2fc02008-08-07 11:05:25 +010040#include <mach/reset.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010041#include <mach/hardware.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Eric Miao28a62382008-12-24 11:32:45 +080043static unsigned long oscr_freq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044static unsigned long sa1100wdt_users;
Raphael Assenata6f052e2009-06-29 13:56:52 -040045static unsigned int pre_margin;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046static int boot_status;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
48/*
49 * Allow only one person to hold it open
50 */
51static int sa1100dog_open(struct inode *inode, struct file *file)
52{
Alan Coxf19e0312008-05-19 14:08:05 +010053 if (test_and_set_bit(1, &sa1100wdt_users))
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 return -EBUSY;
55
56 /* Activate SA1100 Watchdog timer */
57 OSMR3 = OSCR + pre_margin;
58 OSSR = OSSR_M3;
59 OWER = OWER_WME;
60 OIER |= OIER_E3;
Wim Van Sebroeck6abe78b2007-07-24 21:38:37 +000061 return nonseekable_open(inode, file);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062}
63
64/*
Ian Campbell9bbd0372005-08-03 20:34:52 +010065 * The watchdog cannot be disabled.
66 *
67 * Previous comments suggested that turning off the interrupt by
68 * clearing OIER[E3] would prevent the watchdog timing out but this
69 * does not appear to be true (at least on the PXA255).
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 */
71static int sa1100dog_release(struct inode *inode, struct file *file)
72{
Joe Perches27c766a2012-02-15 15:06:19 -080073 pr_crit("Device closed - timer will not stop\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 clear_bit(1, &sa1100wdt_users);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 return 0;
76}
77
Alan Coxf19e0312008-05-19 14:08:05 +010078static ssize_t sa1100dog_write(struct file *file, const char __user *data,
79 size_t len, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
Ian Campbell9bbd0372005-08-03 20:34:52 +010081 if (len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 /* Refresh OSMR3 timer. */
83 OSMR3 = OSCR + pre_margin;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 return len;
85}
86
Alan Coxf19e0312008-05-19 14:08:05 +010087static const struct watchdog_info ident = {
88 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT
89 | WDIOF_KEEPALIVEPING,
Ian Campbell9bbd0372005-08-03 20:34:52 +010090 .identity = "SA1100/PXA255 Watchdog",
Raphael Assenata6f052e2009-06-29 13:56:52 -040091 .firmware_version = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -070092};
93
Alan Coxf19e0312008-05-19 14:08:05 +010094static long sa1100dog_ioctl(struct file *file, unsigned int cmd,
95 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
Samuel Tardieu795b89d2006-09-09 17:34:31 +020097 int ret = -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 int time;
Ian Campbell3a69e572005-11-07 10:21:24 +000099 void __user *argp = (void __user *)arg;
100 int __user *p = argp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
102 switch (cmd) {
103 case WDIOC_GETSUPPORT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000104 ret = copy_to_user(argp, &ident,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 sizeof(ident)) ? -EFAULT : 0;
106 break;
107
108 case WDIOC_GETSTATUS:
Ian Campbell3a69e572005-11-07 10:21:24 +0000109 ret = put_user(0, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 break;
111
112 case WDIOC_GETBOOTSTATUS:
Ian Campbell3a69e572005-11-07 10:21:24 +0000113 ret = put_user(boot_status, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 break;
115
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000116 case WDIOC_KEEPALIVE:
117 OSMR3 = OSCR + pre_margin;
118 ret = 0;
119 break;
120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 case WDIOC_SETTIMEOUT:
Ian Campbell3a69e572005-11-07 10:21:24 +0000122 ret = get_user(time, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 if (ret)
124 break;
125
Raphael Assenata6f052e2009-06-29 13:56:52 -0400126 if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 ret = -EINVAL;
128 break;
129 }
130
Eric Miao28a62382008-12-24 11:32:45 +0800131 pre_margin = oscr_freq * time;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 OSMR3 = OSCR + pre_margin;
133 /*fall through*/
134
135 case WDIOC_GETTIMEOUT:
Eric Miao28a62382008-12-24 11:32:45 +0800136 ret = put_user(pre_margin / oscr_freq, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 }
139 return ret;
140}
141
Alan Coxf19e0312008-05-19 14:08:05 +0100142static const struct file_operations sa1100dog_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 .owner = THIS_MODULE,
144 .llseek = no_llseek,
145 .write = sa1100dog_write,
Alan Coxf19e0312008-05-19 14:08:05 +0100146 .unlocked_ioctl = sa1100dog_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 .open = sa1100dog_open,
148 .release = sa1100dog_release,
149};
150
Alan Coxf19e0312008-05-19 14:08:05 +0100151static struct miscdevice sa1100dog_miscdev = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 .minor = WATCHDOG_MINOR,
Ian Campbell9bbd0372005-08-03 20:34:52 +0100153 .name = "watchdog",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 .fops = &sa1100dog_fops,
155};
156
157static int margin __initdata = 60; /* (secs) Default is 1 minute */
158
159static int __init sa1100dog_init(void)
160{
161 int ret;
162
Eric Miao28a62382008-12-24 11:32:45 +0800163 oscr_freq = get_clock_tick_rate();
164
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 /*
166 * Read the reset status, and save it for later. If
167 * we suspend, RCSR will be cleared, and the watchdog
168 * reset reason will be lost.
169 */
Eric Miao214c6a72008-07-29 14:39:34 +0800170 boot_status = (reset_status & RESET_STATUS_WATCHDOG) ?
171 WDIOF_CARDRESET : 0;
Eric Miao28a62382008-12-24 11:32:45 +0800172 pre_margin = oscr_freq * margin;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
174 ret = misc_register(&sa1100dog_miscdev);
175 if (ret == 0)
Joe Perches27c766a2012-02-15 15:06:19 -0800176 pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
177 margin);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 return ret;
179}
180
181static void __exit sa1100dog_exit(void)
182{
183 misc_deregister(&sa1100dog_miscdev);
184}
185
186module_init(sa1100dog_init);
187module_exit(sa1100dog_exit);
188
189MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
190MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
191
192module_param(margin, int, 0);
193MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
194
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195MODULE_LICENSE("GPL");
196MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);