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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Advantech Single Board Computer WDT driver
3 *
4 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
5 *
6 * Based on acquirewdt.c which is based on wdt.c.
7 * Original copyright messages:
8 *
Alan Cox29fa0582008-10-27 15:17:56 +00009 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
10 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
18 * warranty for any of this software. This material is provided
19 * "AS-IS" and at no charge.
20 *
Alan Cox29fa0582008-10-27 15:17:56 +000021 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 *
23 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
24 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
25 *
26 * 16-Oct-2002 Rob Radez <rob@osinvestor.com>
27 * Clean up ioctls, clean up init + exit, add expect close support,
28 * add wdt_start and wdt_stop as parameters.
29 */
30
Joe Perches27c766a2012-02-15 15:06:19 -080031#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/module.h>
34#include <linux/moduleparam.h>
35#include <linux/types.h>
36#include <linux/miscdevice.h>
37#include <linux/watchdog.h>
38#include <linux/fs.h>
39#include <linux/ioport.h>
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +010040#include <linux/platform_device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <linux/init.h>
Wim Van Sebroeck089ab072008-07-15 11:46:11 +000042#include <linux/io.h>
43#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Wim Van Sebroeck1d747be2007-01-11 22:19:28 +010046#define DRV_NAME "advantechwdt"
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#define WATCHDOG_NAME "Advantech WDT"
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
49
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +000050/* the watchdog platform device */
51static struct platform_device *advwdt_platform_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052static unsigned long advwdt_is_open;
53static char adv_expect_close;
54
55/*
56 * You must set these - there is no sane way to probe for this board.
57 *
58 * To enable or restart, write the timeout value in seconds (1 to 63)
59 * to I/O port wdt_start. To disable, read I/O port wdt_stop.
60 * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
61 * check your manual (at least the PCA-6159 seems to be different -
62 * the manual says wdt_stop is 0x43, not 0x443).
63 * (0x43 is also a write-only control register for the 8254 timer!)
64 */
65
66static int wdt_stop = 0x443;
67module_param(wdt_stop, int, 0);
68MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
69
70static int wdt_start = 0x443;
71module_param(wdt_start, int, 0);
72MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
73
74static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
75module_param(timeout, int, 0);
Alan Coxb6b4d9b2008-05-19 14:04:51 +010076MODULE_PARM_DESC(timeout,
77 "Watchdog timeout in seconds. 1<= timeout <=63, default="
78 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Wim Van Sebroeck86a1e182012-03-05 16:51:11 +010080static bool nowayout = WATCHDOG_NOWAYOUT;
81module_param(nowayout, bool, 0);
Alan Coxb6b4d9b2008-05-19 14:04:51 +010082MODULE_PARM_DESC(nowayout,
83 "Watchdog cannot be stopped once started (default="
84 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
86/*
Wim Van Sebroeck1d747be2007-01-11 22:19:28 +010087 * Watchdog Operations
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 */
89
Alan Coxb6b4d9b2008-05-19 14:04:51 +010090static void advwdt_ping(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
92 /* Write a watchdog value */
93 outb_p(timeout, wdt_start);
94}
95
Alan Coxb6b4d9b2008-05-19 14:04:51 +010096static void advwdt_disable(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
98 inb_p(wdt_stop);
99}
100
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100101static int advwdt_set_heartbeat(int t)
Wim Van Sebroeck0349a362007-01-11 22:27:51 +0100102{
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100103 if (t < 1 || t > 63)
Wim Van Sebroeck0349a362007-01-11 22:27:51 +0100104 return -EINVAL;
Wim Van Sebroeck0349a362007-01-11 22:27:51 +0100105 timeout = t;
106 return 0;
107}
108
Wim Van Sebroeck1d747be2007-01-11 22:19:28 +0100109/*
110 * /dev/watchdog handling
111 */
112
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100113static ssize_t advwdt_write(struct file *file, const char __user *buf,
114 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115{
116 if (count) {
117 if (!nowayout) {
118 size_t i;
119
120 adv_expect_close = 0;
121
122 for (i = 0; i != count; i++) {
123 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000124 if (get_user(c, buf + i))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 return -EFAULT;
126 if (c == 'V')
127 adv_expect_close = 42;
128 }
129 }
130 advwdt_ping();
131 }
132 return count;
133}
134
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100135static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136{
137 int new_timeout;
138 void __user *argp = (void __user *)arg;
139 int __user *p = argp;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000140 static const struct watchdog_info ident = {
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000141 .options = WDIOF_KEEPALIVEPING |
142 WDIOF_SETTIMEOUT |
143 WDIOF_MAGICCLOSE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 .firmware_version = 1,
Wim Van Sebroeck1d747be2007-01-11 22:19:28 +0100145 .identity = WATCHDOG_NAME,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 };
147
148 switch (cmd) {
149 case WDIOC_GETSUPPORT:
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100150 if (copy_to_user(argp, &ident, sizeof(ident)))
151 return -EFAULT;
152 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
154 case WDIOC_GETSTATUS:
155 case WDIOC_GETBOOTSTATUS:
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100156 return put_user(0, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 case WDIOC_SETOPTIONS:
159 {
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100160 int options, retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100162 if (get_user(options, p))
163 return -EFAULT;
164 if (options & WDIOS_DISABLECARD) {
165 advwdt_disable();
166 retval = 0;
167 }
168 if (options & WDIOS_ENABLECARD) {
169 advwdt_ping();
170 retval = 0;
171 }
172 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 }
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000174 case WDIOC_KEEPALIVE:
175 advwdt_ping();
176 break;
177
178 case WDIOC_SETTIMEOUT:
179 if (get_user(new_timeout, p))
180 return -EFAULT;
181 if (advwdt_set_heartbeat(new_timeout))
182 return -EINVAL;
183 advwdt_ping();
184 /* Fall */
185 case WDIOC_GETTIMEOUT:
186 return put_user(timeout, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 default:
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100188 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 }
190 return 0;
191}
192
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100193static int advwdt_open(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194{
195 if (test_and_set_bit(0, &advwdt_is_open))
196 return -EBUSY;
197 /*
198 * Activate
199 */
200
201 advwdt_ping();
202 return nonseekable_open(inode, file);
203}
204
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000205static int advwdt_close(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
207 if (adv_expect_close == 42) {
208 advwdt_disable();
209 } else {
Joe Perches27c766a2012-02-15 15:06:19 -0800210 pr_crit("Unexpected close, not stopping watchdog!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 advwdt_ping();
212 }
213 clear_bit(0, &advwdt_is_open);
214 adv_expect_close = 0;
215 return 0;
216}
217
218/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 * Kernel Interfaces
220 */
221
Arjan van de Ven62322d22006-07-03 00:24:21 -0700222static const struct file_operations advwdt_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 .owner = THIS_MODULE,
224 .llseek = no_llseek,
225 .write = advwdt_write,
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100226 .unlocked_ioctl = advwdt_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 .open = advwdt_open,
228 .release = advwdt_close,
229};
230
231static struct miscdevice advwdt_miscdev = {
Wim Van Sebroeck1d747be2007-01-11 22:19:28 +0100232 .minor = WATCHDOG_MINOR,
233 .name = "watchdog",
234 .fops = &advwdt_fops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235};
236
237/*
Wim Van Sebroeck1d747be2007-01-11 22:19:28 +0100238 * Init & exit routines
239 */
240
Bill Pemberton2d991a12012-11-19 13:21:41 -0500241static int advwdt_probe(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242{
243 int ret;
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 if (wdt_stop != wdt_start) {
246 if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800247 pr_err("I/O address 0x%04x already in use\n",
248 wdt_stop);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 ret = -EIO;
250 goto out;
251 }
252 }
253
254 if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800255 pr_err("I/O address 0x%04x already in use\n", wdt_start);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 ret = -EIO;
257 goto unreg_stop;
258 }
259
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000260 /* Check that the heartbeat value is within it's range ;
261 * if not reset to the default */
Wim Van Sebroeck0349a362007-01-11 22:27:51 +0100262 if (advwdt_set_heartbeat(timeout)) {
263 advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
Joe Perches27c766a2012-02-15 15:06:19 -0800264 pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
Wim Van Sebroeck0349a362007-01-11 22:27:51 +0100265 }
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 ret = misc_register(&advwdt_miscdev);
268 if (ret != 0) {
Joe Perches27c766a2012-02-15 15:06:19 -0800269 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
270 WATCHDOG_MINOR, ret);
Wim Van Sebroeck2e9c9cf2007-01-11 22:42:41 +0100271 goto unreg_regions;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 }
Joe Perches27c766a2012-02-15 15:06:19 -0800273 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 timeout, nowayout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275out:
276 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277unreg_regions:
278 release_region(wdt_start, 1);
279unreg_stop:
280 if (wdt_stop != wdt_start)
281 release_region(wdt_stop, 1);
282 goto out;
283}
284
Bill Pemberton4b12b892012-11-19 13:26:24 -0500285static int advwdt_remove(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286{
287 misc_deregister(&advwdt_miscdev);
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000288 release_region(wdt_start, 1);
289 if (wdt_stop != wdt_start)
290 release_region(wdt_stop, 1);
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +0100291
292 return 0;
293}
294
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100295static void advwdt_shutdown(struct platform_device *dev)
Wim Van Sebroeck2e9c9cf2007-01-11 22:42:41 +0100296{
297 /* Turn the WDT off if we have a soft shutdown */
298 advwdt_disable();
299}
300
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +0100301static struct platform_driver advwdt_driver = {
302 .probe = advwdt_probe,
Bill Pemberton82268712012-11-19 13:21:12 -0500303 .remove = advwdt_remove,
Wim Van Sebroeck2e9c9cf2007-01-11 22:42:41 +0100304 .shutdown = advwdt_shutdown,
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +0100305 .driver = {
306 .owner = THIS_MODULE,
307 .name = DRV_NAME,
308 },
309};
310
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100311static int __init advwdt_init(void)
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +0100312{
313 int err;
314
Joe Perches27c766a2012-02-15 15:06:19 -0800315 pr_info("WDT driver for Advantech single board computer initialising\n");
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +0100316
317 err = platform_driver_register(&advwdt_driver);
318 if (err)
319 return err;
320
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100321 advwdt_platform_device = platform_device_register_simple(DRV_NAME,
322 -1, NULL, 0);
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +0100323 if (IS_ERR(advwdt_platform_device)) {
324 err = PTR_ERR(advwdt_platform_device);
325 goto unreg_platform_driver;
326 }
327
328 return 0;
329
330unreg_platform_driver:
331 platform_driver_unregister(&advwdt_driver);
332 return err;
333}
334
Alan Coxb6b4d9b2008-05-19 14:04:51 +0100335static void __exit advwdt_exit(void)
Wim Van Sebroeckc2bd11c2007-01-11 22:35:40 +0100336{
337 platform_device_unregister(advwdt_platform_device);
338 platform_driver_unregister(&advwdt_driver);
Joe Perches27c766a2012-02-15 15:06:19 -0800339 pr_info("Watchdog Module Unloaded\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340}
341
342module_init(advwdt_init);
343module_exit(advwdt_exit);
344
345MODULE_LICENSE("GPL");
346MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
347MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
348MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);