2 * Eurotech CPU-1220/1410 on board WDT driver
4 * (c) Copyright 2001 Ascensit <support@ascensit.com>
5 * (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com>
6 * (c) Copyright 2002 Rob Radez <rob@osinvestor.com>
9 * Original copyright messages:
11 * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
12 * http://www.redhat.com
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
19 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
20 * warranty for any of this software. This material is provided
21 * "AS-IS" and at no charge.
23 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>*
28 * 2002/04/25 - Rob Radez
31 * make __setup param unique
32 * proper options in watchdog_info
33 * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls
34 * add expect_close support
36 * 2001 - Rodolfo Giometti
39 * 2002.05.30 - Joel Becker <joel.becker@oracle.com>
40 * Added Matt Domsch's nowayout module option.
43 #include <linux/config.h>
44 #include <linux/interrupt.h>
45 #include <linux/module.h>
46 #include <linux/moduleparam.h>
47 #include <linux/types.h>
48 #include <linux/miscdevice.h>
49 #include <linux/watchdog.h>
51 #include <linux/ioport.h>
52 #include <linux/notifier.h>
53 #include <linux/reboot.h>
54 #include <linux/init.h>
57 #include <asm/uaccess.h>
58 #include <asm/system.h>
60 static unsigned long eurwdt_is_open
;
61 static int eurwdt_timeout
;
62 static char eur_expect_close
;
65 * You must set these - there is no sane way to probe for this board.
66 * You can use eurwdt=x,y to set these now.
69 static int io
= 0x3f0;
71 static char *ev
= "int";
73 #define WDT_TIMEOUT 60 /* 1 minute */
75 static int nowayout
= WATCHDOG_NOWAYOUT
;
76 module_param(nowayout
, int, 0);
77 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
83 #define WDT_CTRL_REG 0x30
84 #define WDT_OUTPIN_CFG 0xe2
85 #define WDT_EVENT_INT 0x00
86 #define WDT_EVENT_REBOOT 0x08
87 #define WDT_UNIT_SEL 0xf1
88 #define WDT_UNIT_SECS 0x80
89 #define WDT_TIMEOUT_VAL 0xf2
90 #define WDT_TIMER_CFG 0xf3
93 module_param(io
, int, 0);
94 MODULE_PARM_DESC(io
, "Eurotech WDT io port (default=0x3f0)");
95 module_param(irq
, int, 0);
96 MODULE_PARM_DESC(irq
, "Eurotech WDT irq (default=10)");
97 module_param(ev
, charp
, 0);
98 MODULE_PARM_DESC(ev
, "Eurotech WDT event type (default is `int')");
102 * Programming support
105 static inline void eurwdt_write_reg(u8 index
, u8 data
)
111 static inline void eurwdt_lock_chip(void)
116 static inline void eurwdt_unlock_chip(void)
119 eurwdt_write_reg(0x07, 0x08); /* set the logical device */
122 static inline void eurwdt_set_timeout(int timeout
)
124 eurwdt_write_reg(WDT_TIMEOUT_VAL
, (u8
) timeout
);
127 static inline void eurwdt_disable_timer(void)
129 eurwdt_set_timeout(0);
132 static void eurwdt_activate_timer(void)
134 eurwdt_disable_timer();
135 eurwdt_write_reg(WDT_CTRL_REG
, 0x01); /* activate the WDT */
136 eurwdt_write_reg(WDT_OUTPIN_CFG
, !strcmp("int", ev
) ? WDT_EVENT_INT
: WDT_EVENT_REBOOT
);
138 /* Setting interrupt line */
139 if (irq
== 2 || irq
> 15 || irq
< 0) {
140 printk(KERN_ERR
": invalid irq number\n");
141 irq
= 0; /* if invalid we disable interrupt */
144 printk(KERN_INFO
": interrupt disabled\n");
146 eurwdt_write_reg(WDT_TIMER_CFG
, irq
<<4);
148 eurwdt_write_reg(WDT_UNIT_SEL
, WDT_UNIT_SECS
); /* we use seconds */
149 eurwdt_set_timeout(0); /* the default timeout */
157 static irqreturn_t
eurwdt_interrupt(int irq
, void *dev_id
, struct pt_regs
*regs
)
159 printk(KERN_CRIT
"timeout WDT timeout\n");
162 printk(KERN_CRIT
"Would Reboot.\n");
164 printk(KERN_CRIT
"Initiating system reboot.\n");
174 * Reload counter one with the watchdog timeout.
177 static void eurwdt_ping(void)
179 /* Write the watchdog default value */
180 eurwdt_set_timeout(eurwdt_timeout
);
185 * @file: file handle to the watchdog
186 * @buf: buffer to write (unused as data does not matter here
187 * @count: count of bytes
188 * @ppos: pointer to the position to write. No seeks allowed
190 * A write to a watchdog device is defined as a keepalive signal. Any
191 * write of data will do, as we we don't define content meaning.
194 static ssize_t
eurwdt_write(struct file
*file
, const char __user
*buf
,
195 size_t count
, loff_t
*ppos
)
201 eur_expect_close
= 0;
203 for (i
= 0; i
!= count
; i
++) {
205 if(get_user(c
, buf
+i
))
208 eur_expect_close
= 42;
211 eurwdt_ping(); /* the default timeout */
219 * @inode: inode of the device
220 * @file: file handle to the device
221 * @cmd: watchdog command
222 * @arg: argument pointer
224 * The watchdog API defines a common set of functions for all watchdogs
225 * according to their available features.
228 static int eurwdt_ioctl(struct inode
*inode
, struct file
*file
,
229 unsigned int cmd
, unsigned long arg
)
231 void __user
*argp
= (void __user
*)arg
;
232 int __user
*p
= argp
;
233 static struct watchdog_info ident
= {
234 .options
= WDIOF_KEEPALIVEPING
| WDIOF_SETTIMEOUT
| WDIOF_MAGICCLOSE
,
235 .firmware_version
= 1,
236 .identity
= "WDT Eurotech CPU-1220/1410",
240 int options
, retval
= -EINVAL
;
246 case WDIOC_GETSUPPORT
:
247 return copy_to_user(argp
, &ident
, sizeof(ident
)) ? -EFAULT
: 0;
249 case WDIOC_GETSTATUS
:
250 case WDIOC_GETBOOTSTATUS
:
251 return put_user(0, p
);
253 case WDIOC_KEEPALIVE
:
257 case WDIOC_SETTIMEOUT
:
258 if (copy_from_user(&time
, p
, sizeof(int)))
262 if (time
< 0 || time
> 255)
265 eurwdt_timeout
= time
;
266 eurwdt_set_timeout(time
);
269 case WDIOC_GETTIMEOUT
:
270 return put_user(eurwdt_timeout
, p
);
272 case WDIOC_SETOPTIONS
:
273 if (get_user(options
, p
))
275 if (options
& WDIOS_DISABLECARD
) {
276 eurwdt_disable_timer();
279 if (options
& WDIOS_ENABLECARD
) {
280 eurwdt_activate_timer();
290 * @inode: inode of device
291 * @file: file handle to device
293 * The misc device has been opened. The watchdog device is single
294 * open and on opening we load the counter.
297 static int eurwdt_open(struct inode
*inode
, struct file
*file
)
299 if (test_and_set_bit(0, &eurwdt_is_open
))
301 eurwdt_timeout
= WDT_TIMEOUT
; /* initial timeout */
302 /* Activate the WDT */
303 eurwdt_activate_timer();
304 return nonseekable_open(inode
, file
);
309 * @inode: inode to board
310 * @file: file handle to board
312 * The watchdog has a configurable API. There is a religious dispute
313 * between people who want their watchdog to be able to shut down and
314 * those who want to be sure if the watchdog manager dies the machine
315 * reboots. In the former case we disable the counters, in the latter
316 * case you have to open it again very soon.
319 static int eurwdt_release(struct inode
*inode
, struct file
*file
)
321 if (eur_expect_close
== 42) {
322 eurwdt_disable_timer();
324 printk(KERN_CRIT
"eurwdt: Unexpected close, not stopping watchdog!\n");
327 clear_bit(0, &eurwdt_is_open
);
328 eur_expect_close
= 0;
334 * @this: our notifier block
335 * @code: the event being reported
338 * Our notifier is called on system shutdowns. We want to turn the card
339 * off at reboot otherwise the machine will reboot again during memory
340 * test or worse yet during the following fsck. This would suck, in fact
341 * trust me - if it happens it does suck.
344 static int eurwdt_notify_sys(struct notifier_block
*this, unsigned long code
,
347 if (code
== SYS_DOWN
|| code
== SYS_HALT
) {
348 /* Turn the card off */
349 eurwdt_disable_timer();
360 static struct file_operations eurwdt_fops
= {
361 .owner
= THIS_MODULE
,
363 .write
= eurwdt_write
,
364 .ioctl
= eurwdt_ioctl
,
366 .release
= eurwdt_release
,
369 static struct miscdevice eurwdt_miscdev
= {
370 .minor
= WATCHDOG_MINOR
,
372 .fops
= &eurwdt_fops
,
376 * The WDT card needs to learn about soft shutdowns in order to
377 * turn the timebomb registers off.
380 static struct notifier_block eurwdt_notifier
= {
381 .notifier_call
= eurwdt_notify_sys
,
387 * Unload the watchdog. You cannot do this with any file handles open.
388 * If your watchdog is set to continue ticking on close and you unload
389 * it, well it keeps ticking. We won't get the interrupt but the board
390 * will not touch PC memory so all is fine. You just have to load a new
391 * module in 60 seconds or reboot.
394 static void __exit
eurwdt_exit(void)
398 misc_deregister(&eurwdt_miscdev
);
400 unregister_reboot_notifier(&eurwdt_notifier
);
401 release_region(io
, 2);
408 * Set up the WDT watchdog board. After grabbing the resources
409 * we require we need also to unlock the device.
410 * The open() function will actually kick the board off.
413 static int __init
eurwdt_init(void)
417 ret
= misc_register(&eurwdt_miscdev
);
419 printk(KERN_ERR
"eurwdt: can't misc_register on minor=%d\n",
424 ret
= request_irq(irq
, eurwdt_interrupt
, SA_INTERRUPT
, "eurwdt", NULL
);
426 printk(KERN_ERR
"eurwdt: IRQ %d is not free.\n", irq
);
430 if (!request_region(io
, 2, "eurwdt")) {
431 printk(KERN_ERR
"eurwdt: IO %X is not free.\n", io
);
436 ret
= register_reboot_notifier(&eurwdt_notifier
);
438 printk(KERN_ERR
"eurwdt: can't register reboot notifier (err=%d)\n", ret
);
442 eurwdt_unlock_chip();
445 printk(KERN_INFO
"Eurotech WDT driver 0.01 at %X (Interrupt %d)"
446 " - timeout event: %s\n",
447 io
, irq
, (!strcmp("int", ev
) ? "int" : "reboot"));
453 release_region(io
, 2);
459 misc_deregister(&eurwdt_miscdev
);
463 module_init(eurwdt_init
);
464 module_exit(eurwdt_exit
);
466 MODULE_AUTHOR("Rodolfo Giometti");
467 MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
468 MODULE_LICENSE("GPL");
469 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);