2 * Watchdog driver for the SA11x0/PXA2xx
4 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
5 * Based on SoftDog driver by Alan Cox <alan@redhat.com>
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.
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.
16 * (c) Copyright 2000 Oleg Drokin <green@crimea.edu>
18 * 27/11/2000 Initial release
20 #include <linux/config.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/types.h>
24 #include <linux/kernel.h>
26 #include <linux/miscdevice.h>
27 #include <linux/watchdog.h>
28 #include <linux/init.h>
30 #ifdef CONFIG_ARCH_PXA
31 #include <asm/arch/pxa-regs.h>
34 #include <asm/hardware.h>
35 #include <asm/bitops.h>
36 #include <asm/uaccess.h>
38 #define OSCR_FREQ CLOCK_TICK_RATE
40 static unsigned long sa1100wdt_users
;
41 static int pre_margin
;
42 static int boot_status
;
45 * Allow only one person to hold it open
47 static int sa1100dog_open(struct inode
*inode
, struct file
*file
)
49 nonseekable_open(inode
, file
);
50 if (test_and_set_bit(1,&sa1100wdt_users
))
53 /* Activate SA1100 Watchdog timer */
54 OSMR3
= OSCR
+ pre_margin
;
62 * The watchdog cannot be disabled.
64 * Previous comments suggested that turning off the interrupt by
65 * clearing OIER[E3] would prevent the watchdog timing out but this
66 * does not appear to be true (at least on the PXA255).
68 static int sa1100dog_release(struct inode
*inode
, struct file
*file
)
70 printk(KERN_CRIT
"WATCHDOG: Device closed - timer will not stop\n");
72 clear_bit(1, &sa1100wdt_users
);
77 static ssize_t
sa1100dog_write(struct file
*file
, const char __user
*data
, size_t len
, loff_t
*ppos
)
80 /* Refresh OSMR3 timer. */
81 OSMR3
= OSCR
+ pre_margin
;
86 static struct watchdog_info ident
= {
87 .options
= WDIOF_CARDRESET
| WDIOF_SETTIMEOUT
| WDIOF_KEEPALIVEPING
,
88 .identity
= "SA1100/PXA255 Watchdog",
91 static int sa1100dog_ioctl(struct inode
*inode
, struct file
*file
,
92 unsigned int cmd
, unsigned long arg
)
94 int ret
= -ENOIOCTLCMD
;
96 void __user
*argp
= (void __user
*)arg
;
100 case WDIOC_GETSUPPORT
:
101 ret
= copy_to_user(argp
, &ident
,
102 sizeof(ident
)) ? -EFAULT
: 0;
105 case WDIOC_GETSTATUS
:
106 ret
= put_user(0, p
);
109 case WDIOC_GETBOOTSTATUS
:
110 ret
= put_user(boot_status
, p
);
113 case WDIOC_SETTIMEOUT
:
114 ret
= get_user(time
, p
);
118 if (time
<= 0 || time
> 255) {
123 pre_margin
= OSCR_FREQ
* time
;
124 OSMR3
= OSCR
+ pre_margin
;
127 case WDIOC_GETTIMEOUT
:
128 ret
= put_user(pre_margin
/ OSCR_FREQ
, p
);
131 case WDIOC_KEEPALIVE
:
132 OSMR3
= OSCR
+ pre_margin
;
139 static struct file_operations sa1100dog_fops
=
141 .owner
= THIS_MODULE
,
143 .write
= sa1100dog_write
,
144 .ioctl
= sa1100dog_ioctl
,
145 .open
= sa1100dog_open
,
146 .release
= sa1100dog_release
,
149 static struct miscdevice sa1100dog_miscdev
=
151 .minor
= WATCHDOG_MINOR
,
153 .fops
= &sa1100dog_fops
,
156 static int margin __initdata
= 60; /* (secs) Default is 1 minute */
158 static int __init
sa1100dog_init(void)
163 * Read the reset status, and save it for later. If
164 * we suspend, RCSR will be cleared, and the watchdog
165 * reset reason will be lost.
167 boot_status
= (RCSR
& RCSR_WDR
) ? WDIOF_CARDRESET
: 0;
168 pre_margin
= OSCR_FREQ
* margin
;
170 ret
= misc_register(&sa1100dog_miscdev
);
172 printk("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n",
177 static void __exit
sa1100dog_exit(void)
179 misc_deregister(&sa1100dog_miscdev
);
182 module_init(sa1100dog_init
);
183 module_exit(sa1100dog_exit
);
185 MODULE_AUTHOR("Oleg Drokin <green@crimea.edu>");
186 MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog");
188 module_param(margin
, int, 0);
189 MODULE_PARM_DESC(margin
, "Watchdog margin in seconds (default 60s)");
191 MODULE_LICENSE("GPL");
192 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);