aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/sa1100_wdt.c
diff options
context:
space:
mode:
authorWim Van Sebroeck <wim@iguana.be>2007-08-17 04:38:02 -0400
committerWim Van Sebroeck <wim@iguana.be>2007-10-18 06:39:03 -0400
commitb7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch)
treec52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/sa1100_wdt.c
parentd85714d81cc0408daddb68c10f7fd69eafe7c213 (diff)
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/sa1100_wdt.c')
-rw-r--r--drivers/watchdog/sa1100_wdt.c190
1 files changed, 190 insertions, 0 deletions
diff --git a/drivers/watchdog/sa1100_wdt.c b/drivers/watchdog/sa1100_wdt.c
new file mode 100644
index 000000000000..3475f47aaa45
--- /dev/null
+++ b/drivers/watchdog/sa1100_wdt.c
@@ -0,0 +1,190 @@
1/*
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 */
20#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
38
39static unsigned long sa1100wdt_users;
40static int pre_margin;
41static int boot_status;
42
43/*
44 * Allow only one person to hold it open
45 */
46static int sa1100dog_open(struct inode *inode, struct file *file)
47{
48 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;
56 return nonseekable_open(inode, file);
57}
58
59/*
60 * 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).
65 */
66static int sa1100dog_release(struct inode *inode, struct file *file)
67{
68 printk(KERN_CRIT "WATCHDOG: Device closed - timer will not stop\n");
69
70 clear_bit(1, &sa1100wdt_users);
71
72 return 0;
73}
74
75static ssize_t sa1100dog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
76{
77 if (len)
78 /* Refresh OSMR3 timer. */
79 OSMR3 = OSCR + pre_margin;
80
81 return len;
82}
83
84static struct watchdog_info ident = {
85 .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
86 .identity = "SA1100/PXA255 Watchdog",
87};
88
89static int sa1100dog_ioctl(struct inode *inode, struct file *file,
90 unsigned int cmd, unsigned long arg)
91{
92 int ret = -ENOTTY;
93 int time;
94 void __user *argp = (void __user *)arg;
95 int __user *p = argp;
96
97 switch (cmd) {
98 case WDIOC_GETSUPPORT:
99 ret = copy_to_user(argp, &ident,
100 sizeof(ident)) ? -EFAULT : 0;
101 break;
102
103 case WDIOC_GETSTATUS:
104 ret = put_user(0, p);
105 break;
106
107 case WDIOC_GETBOOTSTATUS:
108 ret = put_user(boot_status, p);
109 break;
110
111 case WDIOC_SETTIMEOUT:
112 ret = get_user(time, p);
113 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:
126 ret = put_user(pre_margin / OSCR_FREQ, p);
127 break;
128
129 case WDIOC_KEEPALIVE:
130 OSMR3 = OSCR + pre_margin;
131 ret = 0;
132 break;
133 }
134 return ret;
135}
136
137static const struct file_operations sa1100dog_fops =
138{
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,
150 .name = "watchdog",
151 .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);
172 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
189MODULE_LICENSE("GPL");
190MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);