1d0173278SGuenter Roeck // SPDX-License-Identifier: GPL-2.0+
2b7e04f8cSWim Van Sebroeck /*
3b7e04f8cSWim Van Sebroeck * ICP Wafer 5823 Single Board Computer WDT driver
4b7e04f8cSWim Van Sebroeck * http://www.icpamerica.com/wafer_5823.php
5b7e04f8cSWim Van Sebroeck * May also work on other similar models
6b7e04f8cSWim Van Sebroeck *
7b7e04f8cSWim Van Sebroeck * (c) Copyright 2002 Justin Cormack <justin@street-vision.com>
8b7e04f8cSWim Van Sebroeck *
9b7e04f8cSWim Van Sebroeck * Release 0.02
10b7e04f8cSWim Van Sebroeck *
11b7e04f8cSWim Van Sebroeck * Based on advantechwdt.c which is based on wdt.c.
12b7e04f8cSWim Van Sebroeck * Original copyright messages:
13b7e04f8cSWim Van Sebroeck *
1429fa0586SAlan Cox * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
1529fa0586SAlan Cox * All Rights Reserved.
16b7e04f8cSWim Van Sebroeck *
17b7e04f8cSWim Van Sebroeck * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
18b7e04f8cSWim Van Sebroeck * warranty for any of this software. This material is provided
19b7e04f8cSWim Van Sebroeck * "AS-IS" and at no charge.
20b7e04f8cSWim Van Sebroeck *
21b7e04f8cSWim Van Sebroeck * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
22b7e04f8cSWim Van Sebroeck *
23b7e04f8cSWim Van Sebroeck */
24b7e04f8cSWim Van Sebroeck
2527c766aaSJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2627c766aaSJoe Perches
27b7e04f8cSWim Van Sebroeck #include <linux/module.h>
28b7e04f8cSWim Van Sebroeck #include <linux/moduleparam.h>
29b7e04f8cSWim Van Sebroeck #include <linux/miscdevice.h>
30b7e04f8cSWim Van Sebroeck #include <linux/watchdog.h>
31b7e04f8cSWim Van Sebroeck #include <linux/fs.h>
32b7e04f8cSWim Van Sebroeck #include <linux/ioport.h>
33b7e04f8cSWim Van Sebroeck #include <linux/notifier.h>
34b7e04f8cSWim Van Sebroeck #include <linux/reboot.h>
35b7e04f8cSWim Van Sebroeck #include <linux/init.h>
36b7e04f8cSWim Van Sebroeck #include <linux/spinlock.h>
37694b16b2SAlan Cox #include <linux/io.h>
38694b16b2SAlan Cox #include <linux/uaccess.h>
39b7e04f8cSWim Van Sebroeck
40b7e04f8cSWim Van Sebroeck #define WATCHDOG_NAME "Wafer 5823 WDT"
41b7e04f8cSWim Van Sebroeck #define PFX WATCHDOG_NAME ": "
42b7e04f8cSWim Van Sebroeck #define WD_TIMO 60 /* 60 sec default timeout */
43b7e04f8cSWim Van Sebroeck
44b7e04f8cSWim Van Sebroeck static unsigned long wafwdt_is_open;
45b7e04f8cSWim Van Sebroeck static char expect_close;
46c7dfd0ccSAlexey Dobriyan static DEFINE_SPINLOCK(wafwdt_lock);
47b7e04f8cSWim Van Sebroeck
48b7e04f8cSWim Van Sebroeck /*
49b7e04f8cSWim Van Sebroeck * You must set these - there is no sane way to probe for this board.
50b7e04f8cSWim Van Sebroeck *
51b7e04f8cSWim Van Sebroeck * To enable, write the timeout value in seconds (1 to 255) to I/O
52b7e04f8cSWim Van Sebroeck * port WDT_START, then read the port to start the watchdog. To pat
53b7e04f8cSWim Van Sebroeck * the dog, read port WDT_STOP to stop the timer, then read WDT_START
54b7e04f8cSWim Van Sebroeck * to restart it again.
55b7e04f8cSWim Van Sebroeck */
56b7e04f8cSWim Van Sebroeck
57b7e04f8cSWim Van Sebroeck static int wdt_stop = 0x843;
58b7e04f8cSWim Van Sebroeck static int wdt_start = 0x443;
59b7e04f8cSWim Van Sebroeck
60b7e04f8cSWim Van Sebroeck static int timeout = WD_TIMO; /* in seconds */
61b7e04f8cSWim Van Sebroeck module_param(timeout, int, 0);
62694b16b2SAlan Cox MODULE_PARM_DESC(timeout,
63694b16b2SAlan Cox "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
64694b16b2SAlan Cox __MODULE_STRING(WD_TIMO) ".");
65b7e04f8cSWim Van Sebroeck
6686a1e189SWim Van Sebroeck static bool nowayout = WATCHDOG_NOWAYOUT;
6786a1e189SWim Van Sebroeck module_param(nowayout, bool, 0);
68694b16b2SAlan Cox MODULE_PARM_DESC(nowayout,
69694b16b2SAlan Cox "Watchdog cannot be stopped once started (default="
70694b16b2SAlan Cox __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
71b7e04f8cSWim Van Sebroeck
wafwdt_ping(void)72b7e04f8cSWim Van Sebroeck static void wafwdt_ping(void)
73b7e04f8cSWim Van Sebroeck {
74b7e04f8cSWim Van Sebroeck /* pat watchdog */
75b7e04f8cSWim Van Sebroeck spin_lock(&wafwdt_lock);
76b7e04f8cSWim Van Sebroeck inb_p(wdt_stop);
77b7e04f8cSWim Van Sebroeck inb_p(wdt_start);
78b7e04f8cSWim Van Sebroeck spin_unlock(&wafwdt_lock);
79b7e04f8cSWim Van Sebroeck }
80b7e04f8cSWim Van Sebroeck
wafwdt_start(void)81b7e04f8cSWim Van Sebroeck static void wafwdt_start(void)
82b7e04f8cSWim Van Sebroeck {
83b7e04f8cSWim Van Sebroeck /* start up watchdog */
84b7e04f8cSWim Van Sebroeck outb_p(timeout, wdt_start);
85b7e04f8cSWim Van Sebroeck inb_p(wdt_start);
86b7e04f8cSWim Van Sebroeck }
87b7e04f8cSWim Van Sebroeck
wafwdt_stop(void)887944d3a5SWim Van Sebroeck static void wafwdt_stop(void)
89b7e04f8cSWim Van Sebroeck {
90b7e04f8cSWim Van Sebroeck /* stop watchdog */
91b7e04f8cSWim Van Sebroeck inb_p(wdt_stop);
92b7e04f8cSWim Van Sebroeck }
93b7e04f8cSWim Van Sebroeck
wafwdt_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)94694b16b2SAlan Cox static ssize_t wafwdt_write(struct file *file, const char __user *buf,
95694b16b2SAlan Cox size_t count, loff_t *ppos)
96b7e04f8cSWim Van Sebroeck {
97b7e04f8cSWim Van Sebroeck /* See if we got the magic character 'V' and reload the timer */
98b7e04f8cSWim Van Sebroeck if (count) {
99b7e04f8cSWim Van Sebroeck if (!nowayout) {
100b7e04f8cSWim Van Sebroeck size_t i;
101b7e04f8cSWim Van Sebroeck
102b7e04f8cSWim Van Sebroeck /* In case it was set long ago */
103b7e04f8cSWim Van Sebroeck expect_close = 0;
104b7e04f8cSWim Van Sebroeck
105694b16b2SAlan Cox /* scan to see whether or not we got the magic
106694b16b2SAlan Cox character */
107b7e04f8cSWim Van Sebroeck for (i = 0; i != count; i++) {
108b7e04f8cSWim Van Sebroeck char c;
109b7e04f8cSWim Van Sebroeck if (get_user(c, buf + i))
110b7e04f8cSWim Van Sebroeck return -EFAULT;
111b7e04f8cSWim Van Sebroeck if (c == 'V')
112b7e04f8cSWim Van Sebroeck expect_close = 42;
113b7e04f8cSWim Van Sebroeck }
114b7e04f8cSWim Van Sebroeck }
115694b16b2SAlan Cox /* Well, anyhow someone wrote to us, we should
116694b16b2SAlan Cox return that favour */
117b7e04f8cSWim Van Sebroeck wafwdt_ping();
118b7e04f8cSWim Van Sebroeck }
119b7e04f8cSWim Van Sebroeck return count;
120b7e04f8cSWim Van Sebroeck }
121b7e04f8cSWim Van Sebroeck
wafwdt_ioctl(struct file * file,unsigned int cmd,unsigned long arg)122694b16b2SAlan Cox static long wafwdt_ioctl(struct file *file, unsigned int cmd,
123b7e04f8cSWim Van Sebroeck unsigned long arg)
124b7e04f8cSWim Van Sebroeck {
125b7e04f8cSWim Van Sebroeck int new_timeout;
126b7e04f8cSWim Van Sebroeck void __user *argp = (void __user *)arg;
127b7e04f8cSWim Van Sebroeck int __user *p = argp;
128694b16b2SAlan Cox static const struct watchdog_info ident = {
129694b16b2SAlan Cox .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
130694b16b2SAlan Cox WDIOF_MAGICCLOSE,
131b7e04f8cSWim Van Sebroeck .firmware_version = 1,
132b7e04f8cSWim Van Sebroeck .identity = "Wafer 5823 WDT",
133b7e04f8cSWim Van Sebroeck };
134b7e04f8cSWim Van Sebroeck
135b7e04f8cSWim Van Sebroeck switch (cmd) {
136b7e04f8cSWim Van Sebroeck case WDIOC_GETSUPPORT:
137b7e04f8cSWim Van Sebroeck if (copy_to_user(argp, &ident, sizeof(ident)))
138b7e04f8cSWim Van Sebroeck return -EFAULT;
139b7e04f8cSWim Van Sebroeck break;
140b7e04f8cSWim Van Sebroeck
141b7e04f8cSWim Van Sebroeck case WDIOC_GETSTATUS:
142b7e04f8cSWim Van Sebroeck case WDIOC_GETBOOTSTATUS:
143b7e04f8cSWim Van Sebroeck return put_user(0, p);
144b7e04f8cSWim Van Sebroeck
145b7e04f8cSWim Van Sebroeck case WDIOC_SETOPTIONS:
146b7e04f8cSWim Van Sebroeck {
147b7e04f8cSWim Van Sebroeck int options, retval = -EINVAL;
148b7e04f8cSWim Van Sebroeck
149b7e04f8cSWim Van Sebroeck if (get_user(options, p))
150b7e04f8cSWim Van Sebroeck return -EFAULT;
151b7e04f8cSWim Van Sebroeck
152b7e04f8cSWim Van Sebroeck if (options & WDIOS_DISABLECARD) {
1538a062ac6SAxel Lin wafwdt_stop();
154b7e04f8cSWim Van Sebroeck retval = 0;
155b7e04f8cSWim Van Sebroeck }
156b7e04f8cSWim Van Sebroeck
157b7e04f8cSWim Van Sebroeck if (options & WDIOS_ENABLECARD) {
1588a062ac6SAxel Lin wafwdt_start();
159b7e04f8cSWim Van Sebroeck retval = 0;
160b7e04f8cSWim Van Sebroeck }
161b7e04f8cSWim Van Sebroeck
162b7e04f8cSWim Van Sebroeck return retval;
163b7e04f8cSWim Van Sebroeck }
164b7e04f8cSWim Van Sebroeck
1650c06090cSWim Van Sebroeck case WDIOC_KEEPALIVE:
1660c06090cSWim Van Sebroeck wafwdt_ping();
1670c06090cSWim Van Sebroeck break;
1680c06090cSWim Van Sebroeck
1690c06090cSWim Van Sebroeck case WDIOC_SETTIMEOUT:
1700c06090cSWim Van Sebroeck if (get_user(new_timeout, p))
1710c06090cSWim Van Sebroeck return -EFAULT;
1720c06090cSWim Van Sebroeck if ((new_timeout < 1) || (new_timeout > 255))
1730c06090cSWim Van Sebroeck return -EINVAL;
1740c06090cSWim Van Sebroeck timeout = new_timeout;
1750c06090cSWim Van Sebroeck wafwdt_stop();
1760c06090cSWim Van Sebroeck wafwdt_start();
177*bd490f82SGustavo A. R. Silva fallthrough;
1780c06090cSWim Van Sebroeck case WDIOC_GETTIMEOUT:
1790c06090cSWim Van Sebroeck return put_user(timeout, p);
1800c06090cSWim Van Sebroeck
181b7e04f8cSWim Van Sebroeck default:
182b7e04f8cSWim Van Sebroeck return -ENOTTY;
183b7e04f8cSWim Van Sebroeck }
184b7e04f8cSWim Van Sebroeck return 0;
185b7e04f8cSWim Van Sebroeck }
186b7e04f8cSWim Van Sebroeck
wafwdt_open(struct inode * inode,struct file * file)187b7e04f8cSWim Van Sebroeck static int wafwdt_open(struct inode *inode, struct file *file)
188b7e04f8cSWim Van Sebroeck {
189b7e04f8cSWim Van Sebroeck if (test_and_set_bit(0, &wafwdt_is_open))
190b7e04f8cSWim Van Sebroeck return -EBUSY;
191b7e04f8cSWim Van Sebroeck
192b7e04f8cSWim Van Sebroeck /*
193b7e04f8cSWim Van Sebroeck * Activate
194b7e04f8cSWim Van Sebroeck */
195b7e04f8cSWim Van Sebroeck wafwdt_start();
196c5bf68feSKirill Smelkov return stream_open(inode, file);
197b7e04f8cSWim Van Sebroeck }
198b7e04f8cSWim Van Sebroeck
wafwdt_close(struct inode * inode,struct file * file)1997944d3a5SWim Van Sebroeck static int wafwdt_close(struct inode *inode, struct file *file)
200b7e04f8cSWim Van Sebroeck {
201694b16b2SAlan Cox if (expect_close == 42)
202b7e04f8cSWim Van Sebroeck wafwdt_stop();
203694b16b2SAlan Cox else {
20427c766aaSJoe Perches pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
205b7e04f8cSWim Van Sebroeck wafwdt_ping();
206b7e04f8cSWim Van Sebroeck }
207b7e04f8cSWim Van Sebroeck clear_bit(0, &wafwdt_is_open);
208b7e04f8cSWim Van Sebroeck expect_close = 0;
209b7e04f8cSWim Van Sebroeck return 0;
210b7e04f8cSWim Van Sebroeck }
211b7e04f8cSWim Van Sebroeck
212b7e04f8cSWim Van Sebroeck /*
213b7e04f8cSWim Van Sebroeck * Notifier for system down
214b7e04f8cSWim Van Sebroeck */
215b7e04f8cSWim Van Sebroeck
wafwdt_notify_sys(struct notifier_block * this,unsigned long code,void * unused)216694b16b2SAlan Cox static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
217694b16b2SAlan Cox void *unused)
218b7e04f8cSWim Van Sebroeck {
219694b16b2SAlan Cox if (code == SYS_DOWN || code == SYS_HALT)
220b7e04f8cSWim Van Sebroeck wafwdt_stop();
221b7e04f8cSWim Van Sebroeck return NOTIFY_DONE;
222b7e04f8cSWim Van Sebroeck }
223b7e04f8cSWim Van Sebroeck
224b7e04f8cSWim Van Sebroeck /*
225b7e04f8cSWim Van Sebroeck * Kernel Interfaces
226b7e04f8cSWim Van Sebroeck */
227b7e04f8cSWim Van Sebroeck
228b7e04f8cSWim Van Sebroeck static const struct file_operations wafwdt_fops = {
229b7e04f8cSWim Van Sebroeck .owner = THIS_MODULE,
230b7e04f8cSWim Van Sebroeck .llseek = no_llseek,
231b7e04f8cSWim Van Sebroeck .write = wafwdt_write,
232694b16b2SAlan Cox .unlocked_ioctl = wafwdt_ioctl,
233b6dfb247SArnd Bergmann .compat_ioctl = compat_ptr_ioctl,
234b7e04f8cSWim Van Sebroeck .open = wafwdt_open,
235b7e04f8cSWim Van Sebroeck .release = wafwdt_close,
236b7e04f8cSWim Van Sebroeck };
237b7e04f8cSWim Van Sebroeck
238b7e04f8cSWim Van Sebroeck static struct miscdevice wafwdt_miscdev = {
239b7e04f8cSWim Van Sebroeck .minor = WATCHDOG_MINOR,
240b7e04f8cSWim Van Sebroeck .name = "watchdog",
241b7e04f8cSWim Van Sebroeck .fops = &wafwdt_fops,
242b7e04f8cSWim Van Sebroeck };
243b7e04f8cSWim Van Sebroeck
244b7e04f8cSWim Van Sebroeck /*
245b7e04f8cSWim Van Sebroeck * The WDT needs to learn about soft shutdowns in order to
246b7e04f8cSWim Van Sebroeck * turn the timebomb registers off.
247b7e04f8cSWim Van Sebroeck */
248b7e04f8cSWim Van Sebroeck
249b7e04f8cSWim Van Sebroeck static struct notifier_block wafwdt_notifier = {
250b7e04f8cSWim Van Sebroeck .notifier_call = wafwdt_notify_sys,
251b7e04f8cSWim Van Sebroeck };
252b7e04f8cSWim Van Sebroeck
wafwdt_init(void)253b7e04f8cSWim Van Sebroeck static int __init wafwdt_init(void)
254b7e04f8cSWim Van Sebroeck {
255b7e04f8cSWim Van Sebroeck int ret;
256b7e04f8cSWim Van Sebroeck
25727c766aaSJoe Perches pr_info("WDT driver for Wafer 5823 single board computer initialising\n");
258b7e04f8cSWim Van Sebroeck
259b7e04f8cSWim Van Sebroeck if (timeout < 1 || timeout > 255) {
260b7e04f8cSWim Van Sebroeck timeout = WD_TIMO;
26127c766aaSJoe Perches pr_info("timeout value must be 1 <= x <= 255, using %d\n",
262b7e04f8cSWim Van Sebroeck timeout);
263b7e04f8cSWim Van Sebroeck }
264b7e04f8cSWim Van Sebroeck
265b7e04f8cSWim Van Sebroeck if (wdt_stop != wdt_start) {
266b7e04f8cSWim Van Sebroeck if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
26727c766aaSJoe Perches pr_err("I/O address 0x%04x already in use\n", wdt_stop);
268b7e04f8cSWim Van Sebroeck ret = -EIO;
269b7e04f8cSWim Van Sebroeck goto error;
270b7e04f8cSWim Van Sebroeck }
271b7e04f8cSWim Van Sebroeck }
272b7e04f8cSWim Van Sebroeck
273b7e04f8cSWim Van Sebroeck if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
27427c766aaSJoe Perches pr_err("I/O address 0x%04x already in use\n", wdt_start);
275b7e04f8cSWim Van Sebroeck ret = -EIO;
276b7e04f8cSWim Van Sebroeck goto error2;
277b7e04f8cSWim Van Sebroeck }
278b7e04f8cSWim Van Sebroeck
279b7e04f8cSWim Van Sebroeck ret = register_reboot_notifier(&wafwdt_notifier);
280b7e04f8cSWim Van Sebroeck if (ret != 0) {
28127c766aaSJoe Perches pr_err("cannot register reboot notifier (err=%d)\n", ret);
282b7e04f8cSWim Van Sebroeck goto error3;
283b7e04f8cSWim Van Sebroeck }
284b7e04f8cSWim Van Sebroeck
285b7e04f8cSWim Van Sebroeck ret = misc_register(&wafwdt_miscdev);
286b7e04f8cSWim Van Sebroeck if (ret != 0) {
28727c766aaSJoe Perches pr_err("cannot register miscdev on minor=%d (err=%d)\n",
288b7e04f8cSWim Van Sebroeck WATCHDOG_MINOR, ret);
289b7e04f8cSWim Van Sebroeck goto error4;
290b7e04f8cSWim Van Sebroeck }
291b7e04f8cSWim Van Sebroeck
29227c766aaSJoe Perches pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
293b7e04f8cSWim Van Sebroeck timeout, nowayout);
294b7e04f8cSWim Van Sebroeck
295b7e04f8cSWim Van Sebroeck return ret;
296b7e04f8cSWim Van Sebroeck error4:
297b7e04f8cSWim Van Sebroeck unregister_reboot_notifier(&wafwdt_notifier);
298b7e04f8cSWim Van Sebroeck error3:
299b7e04f8cSWim Van Sebroeck release_region(wdt_start, 1);
300b7e04f8cSWim Van Sebroeck error2:
301b7e04f8cSWim Van Sebroeck if (wdt_stop != wdt_start)
302b7e04f8cSWim Van Sebroeck release_region(wdt_stop, 1);
303b7e04f8cSWim Van Sebroeck error:
304b7e04f8cSWim Van Sebroeck return ret;
305b7e04f8cSWim Van Sebroeck }
306b7e04f8cSWim Van Sebroeck
wafwdt_exit(void)307b7e04f8cSWim Van Sebroeck static void __exit wafwdt_exit(void)
308b7e04f8cSWim Van Sebroeck {
309b7e04f8cSWim Van Sebroeck misc_deregister(&wafwdt_miscdev);
310b7e04f8cSWim Van Sebroeck unregister_reboot_notifier(&wafwdt_notifier);
311b7e04f8cSWim Van Sebroeck if (wdt_stop != wdt_start)
312b7e04f8cSWim Van Sebroeck release_region(wdt_stop, 1);
313b7e04f8cSWim Van Sebroeck release_region(wdt_start, 1);
314b7e04f8cSWim Van Sebroeck }
315b7e04f8cSWim Van Sebroeck
316b7e04f8cSWim Van Sebroeck module_init(wafwdt_init);
317b7e04f8cSWim Van Sebroeck module_exit(wafwdt_exit);
318b7e04f8cSWim Van Sebroeck
319b7e04f8cSWim Van Sebroeck MODULE_AUTHOR("Justin Cormack");
320b7e04f8cSWim Van Sebroeck MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
321b7e04f8cSWim Van Sebroeck MODULE_LICENSE("GPL");
322b7e04f8cSWim Van Sebroeck
323b7e04f8cSWim Van Sebroeck /* end of wafer5823wdt.c */
324