2 * Driver for the MTX-1 Watchdog.
4 * (C) Copyright 2005 4G Systems <info@4g-systems.biz>,
6 * http://www.4g-systems.biz
8 * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
15 * Neither Michael Stickel nor 4G Systems admit liability nor provide
16 * warranty for any of this software. This material is provided
17 * "AS-IS" and at no charge.
19 * (c) Copyright 2005 4G Systems <info@4g-systems.biz>
22 * Author: Michael Stickel michael.stickel@4g-systems.biz
25 * Author: Florian Fainelli florian@openwrt.org
26 * use the Linux watchdog/timer APIs
28 * The Watchdog is configured to reset the MTX-1
29 * if it is not triggered for 100 seconds.
30 * It should not be triggered more often than 1.6 seconds.
32 * A timer triggers the watchdog every 5 seconds, until
33 * it is opened for the first time. After the first open
34 * it MUST be triggered every 2..95 seconds.
37 #include <linux/module.h>
38 #include <linux/moduleparam.h>
39 #include <linux/types.h>
40 #include <linux/errno.h>
41 #include <linux/miscdevice.h>
43 #include <linux/init.h>
44 #include <linux/ioport.h>
45 #include <linux/timer.h>
46 #include <linux/completion.h>
47 #include <linux/jiffies.h>
48 #include <linux/watchdog.h>
49 #include <linux/platform_device.h>
51 #include <linux/uaccess.h>
52 #include <linux/gpio.h>
54 #include <asm/mach-au1x00/au1000.h>
56 #define MTX1_WDT_INTERVAL (5 * HZ)
58 static int ticks
= 100 * HZ
;
61 struct completion stop
;
64 struct timer_list timer
;
71 static void mtx1_wdt_trigger(unsigned long unused
)
75 spin_lock(&mtx1_wdt_device
.lock
);
76 if (mtx1_wdt_device
.running
)
81 tmp
= au_readl(GPIO2_DIR
);
82 tmp
= (tmp
& ~(1 << mtx1_wdt_device
.gpio
)) |
83 ((~tmp
) & (1 << mtx1_wdt_device
.gpio
));
84 au_writel(tmp
, GPIO2_DIR
);
86 if (mtx1_wdt_device
.queue
&& ticks
)
87 mod_timer(&mtx1_wdt_device
.timer
, jiffies
+ MTX1_WDT_INTERVAL
);
89 complete(&mtx1_wdt_device
.stop
);
90 spin_unlock(&mtx1_wdt_device
.lock
);
93 static void mtx1_wdt_reset(void)
95 ticks
= mtx1_wdt_device
.default_ticks
;
99 static void mtx1_wdt_start(void)
101 spin_lock_irqsave(&mtx1_wdt_device
.lock
, flags
);
102 if (!mtx1_wdt_device
.queue
) {
103 mtx1_wdt_device
.queue
= 1;
104 gpio_set_value(mtx1_wdt_device
.gpio
, 1);
105 mod_timer(&mtx1_wdt_device
.timer
, jiffies
+ MTX1_WDT_INTERVAL
);
107 mtx1_wdt_device
.running
++;
108 spin_unlock_irqrestore(&mtx1_wdt_device
.lock
, flags
);
111 static int mtx1_wdt_stop(void)
113 spin_lock_irqsave(&mtx1_wdt_device
.lock
, flags
);
114 if (mtx1_wdt_device
.queue
) {
115 mtx1_wdt_device
.queue
= 0;
116 gpio_set_value(mtx1_wdt_device
.gpio
, 0);
118 ticks
= mtx1_wdt_device
.default_ticks
;
119 spin_unlock_irqrestore(&mtx1_wdt_device
.lock
, flags
);
123 /* Filesystem functions */
125 static int mtx1_wdt_open(struct inode
*inode
, struct file
*file
)
127 if (test_and_set_bit(0, &mtx1_wdt_device
.inuse
))
129 return nonseekable_open(inode
, file
);
133 static int mtx1_wdt_release(struct inode
*inode
, struct file
*file
)
135 clear_bit(0, &mtx1_wdt_device
.inuse
);
139 static long mtx1_wdt_ioctl(struct file
*file
, unsigned int cmd
,
142 void __user
*argp
= (void __user
*)arg
;
143 int __user
*p
= (int __user
*)argp
;
145 static const struct watchdog_info ident
= {
146 .options
= WDIOF_CARDRESET
,
147 .identity
= "MTX-1 WDT",
151 case WDIOC_GETSUPPORT
:
152 if (copy_to_user(argp
, &ident
, sizeof(ident
)))
155 case WDIOC_GETSTATUS
:
156 case WDIOC_GETBOOTSTATUS
:
159 case WDIOC_SETOPTIONS
:
160 if (get_user(value
, p
))
162 if (value
& WDIOS_ENABLECARD
)
164 else if (value
& WDIOS_DISABLECARD
)
169 case WDIOC_KEEPALIVE
:
179 static ssize_t
mtx1_wdt_write(struct file
*file
, const char *buf
,
180 size_t count
, loff_t
*ppos
)
188 static const struct file_operations mtx1_wdt_fops
= {
189 .owner
= THIS_MODULE
,
191 .unlocked_ioctl
= mtx1_wdt_ioctl
,
192 .open
= mtx1_wdt_open
,
193 .write
= mtx1_wdt_write
,
194 .release
= mtx1_wdt_release
,
198 static struct miscdevice mtx1_wdt_misc
= {
199 .minor
= WATCHDOG_MINOR
,
201 .fops
= &mtx1_wdt_fops
,
205 static int mtx1_wdt_probe(struct platform_device
*pdev
)
209 mtx1_wdt_device
.gpio
= pdev
->resource
[0].start
;
211 spin_lock_init(&mtx1_wdt_device
.lock
);
212 init_completion(&mtx1_wdt_device
.stop
);
213 mtx1_wdt_device
.queue
= 0;
214 clear_bit(0, &mtx1_wdt_device
.inuse
);
215 setup_timer(&mtx1_wdt_device
.timer
, mtx1_wdt_trigger
, 0L);
216 mtx1_wdt_device
.default_ticks
= ticks
;
218 ret
= misc_register(&mtx1_wdt_misc
);
220 printk(KERN_ERR
" mtx-1_wdt : failed to register\n");
224 printk(KERN_INFO
"MTX-1 Watchdog driver\n");
228 static int mtx1_wdt_remove(struct platform_device
*pdev
)
230 /* FIXME: do we need to lock this test ? */
231 if (mtx1_wdt_device
.queue
) {
232 mtx1_wdt_device
.queue
= 0;
233 wait_for_completion(&mtx1_wdt_device
.stop
);
235 misc_deregister(&mtx1_wdt_misc
);
239 static struct platform_driver mtx1_wdt
= {
240 .probe
= mtx1_wdt_probe
,
241 .remove
= mtx1_wdt_remove
,
242 .driver
.name
= "mtx1-wdt",
243 .driver
.owner
= THIS_MODULE
,
246 static int __init
mtx1_wdt_init(void)
248 return platform_driver_register(&mtx1_wdt
);
251 static void __exit
mtx1_wdt_exit(void)
253 platform_driver_unregister(&mtx1_wdt
);
256 module_init(mtx1_wdt_init
);
257 module_exit(mtx1_wdt_exit
);
259 MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
260 MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
261 MODULE_LICENSE("GPL");
262 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);
263 MODULE_ALIAS("platform:mtx1-wdt");