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d0173278 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
1da177e4 LT |
2 | /* |
3 | * Advantech Single Board Computer WDT driver | |
4 | * | |
5 | * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> | |
6 | * | |
7 | * Based on acquirewdt.c which is based on wdt.c. | |
8 | * Original copyright messages: | |
9 | * | |
29fa0586 AC |
10 | * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>, |
11 | * All Rights Reserved. | |
1da177e4 | 12 | * |
1da177e4 LT |
13 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide |
14 | * warranty for any of this software. This material is provided | |
15 | * "AS-IS" and at no charge. | |
16 | * | |
29fa0586 | 17 | * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
18 | * |
19 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> | |
20 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT | |
21 | * | |
22 | * 16-Oct-2002 Rob Radez <rob@osinvestor.com> | |
23 | * Clean up ioctls, clean up init + exit, add expect close support, | |
24 | * add wdt_start and wdt_stop as parameters. | |
25 | */ | |
26 | ||
27c766aa JP |
27 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
28 | ||
1da177e4 LT |
29 | #include <linux/module.h> |
30 | #include <linux/moduleparam.h> | |
31 | #include <linux/types.h> | |
32 | #include <linux/miscdevice.h> | |
33 | #include <linux/watchdog.h> | |
34 | #include <linux/fs.h> | |
35 | #include <linux/ioport.h> | |
c2bd11c7 | 36 | #include <linux/platform_device.h> |
1da177e4 | 37 | #include <linux/init.h> |
089ab079 WVS |
38 | #include <linux/io.h> |
39 | #include <linux/uaccess.h> | |
1da177e4 | 40 | |
1da177e4 | 41 | |
1d747be6 | 42 | #define DRV_NAME "advantechwdt" |
1da177e4 | 43 | #define WATCHDOG_NAME "Advantech WDT" |
1da177e4 LT |
44 | #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ |
45 | ||
7944d3a5 WVS |
46 | /* the watchdog platform device */ |
47 | static struct platform_device *advwdt_platform_device; | |
1da177e4 LT |
48 | static unsigned long advwdt_is_open; |
49 | static char adv_expect_close; | |
50 | ||
51 | /* | |
52 | * You must set these - there is no sane way to probe for this board. | |
53 | * | |
54 | * To enable or restart, write the timeout value in seconds (1 to 63) | |
55 | * to I/O port wdt_start. To disable, read I/O port wdt_stop. | |
56 | * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but | |
57 | * check your manual (at least the PCA-6159 seems to be different - | |
58 | * the manual says wdt_stop is 0x43, not 0x443). | |
59 | * (0x43 is also a write-only control register for the 8254 timer!) | |
60 | */ | |
61 | ||
62 | static int wdt_stop = 0x443; | |
63 | module_param(wdt_stop, int, 0); | |
64 | MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)"); | |
65 | ||
66 | static int wdt_start = 0x443; | |
67 | module_param(wdt_start, int, 0); | |
68 | MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)"); | |
69 | ||
70 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ | |
71 | module_param(timeout, int, 0); | |
b6b4d9b8 AC |
72 | MODULE_PARM_DESC(timeout, |
73 | "Watchdog timeout in seconds. 1<= timeout <=63, default=" | |
74 | __MODULE_STRING(WATCHDOG_TIMEOUT) "."); | |
1da177e4 | 75 | |
86a1e189 WVS |
76 | static bool nowayout = WATCHDOG_NOWAYOUT; |
77 | module_param(nowayout, bool, 0); | |
b6b4d9b8 AC |
78 | MODULE_PARM_DESC(nowayout, |
79 | "Watchdog cannot be stopped once started (default=" | |
80 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
81 | |
82 | /* | |
1d747be6 | 83 | * Watchdog Operations |
1da177e4 LT |
84 | */ |
85 | ||
b6b4d9b8 | 86 | static void advwdt_ping(void) |
1da177e4 LT |
87 | { |
88 | /* Write a watchdog value */ | |
89 | outb_p(timeout, wdt_start); | |
90 | } | |
91 | ||
b6b4d9b8 | 92 | static void advwdt_disable(void) |
1da177e4 LT |
93 | { |
94 | inb_p(wdt_stop); | |
95 | } | |
96 | ||
b6b4d9b8 | 97 | static int advwdt_set_heartbeat(int t) |
0349a363 | 98 | { |
b6b4d9b8 | 99 | if (t < 1 || t > 63) |
0349a363 | 100 | return -EINVAL; |
0349a363 WVS |
101 | timeout = t; |
102 | return 0; | |
103 | } | |
104 | ||
1d747be6 WVS |
105 | /* |
106 | * /dev/watchdog handling | |
107 | */ | |
108 | ||
b6b4d9b8 AC |
109 | static ssize_t advwdt_write(struct file *file, const char __user *buf, |
110 | size_t count, loff_t *ppos) | |
1da177e4 LT |
111 | { |
112 | if (count) { | |
113 | if (!nowayout) { | |
114 | size_t i; | |
115 | ||
116 | adv_expect_close = 0; | |
117 | ||
118 | for (i = 0; i != count; i++) { | |
119 | char c; | |
7944d3a5 | 120 | if (get_user(c, buf + i)) |
1da177e4 LT |
121 | return -EFAULT; |
122 | if (c == 'V') | |
123 | adv_expect_close = 42; | |
124 | } | |
125 | } | |
126 | advwdt_ping(); | |
127 | } | |
128 | return count; | |
129 | } | |
130 | ||
b6b4d9b8 | 131 | static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
132 | { |
133 | int new_timeout; | |
134 | void __user *argp = (void __user *)arg; | |
135 | int __user *p = argp; | |
42747d71 | 136 | static const struct watchdog_info ident = { |
143a2e54 WVS |
137 | .options = WDIOF_KEEPALIVEPING | |
138 | WDIOF_SETTIMEOUT | | |
139 | WDIOF_MAGICCLOSE, | |
1da177e4 | 140 | .firmware_version = 1, |
1d747be6 | 141 | .identity = WATCHDOG_NAME, |
1da177e4 LT |
142 | }; |
143 | ||
144 | switch (cmd) { | |
145 | case WDIOC_GETSUPPORT: | |
b6b4d9b8 AC |
146 | if (copy_to_user(argp, &ident, sizeof(ident))) |
147 | return -EFAULT; | |
148 | break; | |
1da177e4 LT |
149 | |
150 | case WDIOC_GETSTATUS: | |
151 | case WDIOC_GETBOOTSTATUS: | |
b6b4d9b8 | 152 | return put_user(0, p); |
1da177e4 | 153 | |
1da177e4 LT |
154 | case WDIOC_SETOPTIONS: |
155 | { | |
b6b4d9b8 | 156 | int options, retval = -EINVAL; |
1da177e4 | 157 | |
b6b4d9b8 AC |
158 | if (get_user(options, p)) |
159 | return -EFAULT; | |
160 | if (options & WDIOS_DISABLECARD) { | |
161 | advwdt_disable(); | |
162 | retval = 0; | |
163 | } | |
164 | if (options & WDIOS_ENABLECARD) { | |
165 | advwdt_ping(); | |
166 | retval = 0; | |
167 | } | |
168 | return retval; | |
1da177e4 | 169 | } |
0c06090c WVS |
170 | case WDIOC_KEEPALIVE: |
171 | advwdt_ping(); | |
172 | break; | |
173 | ||
174 | case WDIOC_SETTIMEOUT: | |
175 | if (get_user(new_timeout, p)) | |
176 | return -EFAULT; | |
177 | if (advwdt_set_heartbeat(new_timeout)) | |
178 | return -EINVAL; | |
179 | advwdt_ping(); | |
bd490f82 | 180 | fallthrough; |
0c06090c WVS |
181 | case WDIOC_GETTIMEOUT: |
182 | return put_user(timeout, p); | |
1da177e4 | 183 | default: |
b6b4d9b8 | 184 | return -ENOTTY; |
1da177e4 LT |
185 | } |
186 | return 0; | |
187 | } | |
188 | ||
b6b4d9b8 | 189 | static int advwdt_open(struct inode *inode, struct file *file) |
1da177e4 LT |
190 | { |
191 | if (test_and_set_bit(0, &advwdt_is_open)) | |
192 | return -EBUSY; | |
193 | /* | |
194 | * Activate | |
195 | */ | |
196 | ||
197 | advwdt_ping(); | |
c5bf68fe | 198 | return stream_open(inode, file); |
1da177e4 LT |
199 | } |
200 | ||
7944d3a5 | 201 | static int advwdt_close(struct inode *inode, struct file *file) |
1da177e4 LT |
202 | { |
203 | if (adv_expect_close == 42) { | |
204 | advwdt_disable(); | |
205 | } else { | |
27c766aa | 206 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
1da177e4 LT |
207 | advwdt_ping(); |
208 | } | |
209 | clear_bit(0, &advwdt_is_open); | |
210 | adv_expect_close = 0; | |
211 | return 0; | |
212 | } | |
213 | ||
1da177e4 LT |
214 | /* |
215 | * Kernel Interfaces | |
216 | */ | |
217 | ||
62322d25 | 218 | static const struct file_operations advwdt_fops = { |
1da177e4 LT |
219 | .owner = THIS_MODULE, |
220 | .llseek = no_llseek, | |
221 | .write = advwdt_write, | |
b6b4d9b8 | 222 | .unlocked_ioctl = advwdt_ioctl, |
b6dfb247 | 223 | .compat_ioctl = compat_ptr_ioctl, |
1da177e4 LT |
224 | .open = advwdt_open, |
225 | .release = advwdt_close, | |
226 | }; | |
227 | ||
228 | static struct miscdevice advwdt_miscdev = { | |
1d747be6 WVS |
229 | .minor = WATCHDOG_MINOR, |
230 | .name = "watchdog", | |
231 | .fops = &advwdt_fops, | |
1da177e4 LT |
232 | }; |
233 | ||
1d747be6 WVS |
234 | /* |
235 | * Init & exit routines | |
236 | */ | |
237 | ||
acaaaf62 | 238 | static int __init advwdt_probe(struct platform_device *dev) |
1da177e4 LT |
239 | { |
240 | int ret; | |
241 | ||
1da177e4 LT |
242 | if (wdt_stop != wdt_start) { |
243 | if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) { | |
27c766aa JP |
244 | pr_err("I/O address 0x%04x already in use\n", |
245 | wdt_stop); | |
1da177e4 LT |
246 | ret = -EIO; |
247 | goto out; | |
248 | } | |
249 | } | |
250 | ||
251 | if (!request_region(wdt_start, 1, WATCHDOG_NAME)) { | |
27c766aa | 252 | pr_err("I/O address 0x%04x already in use\n", wdt_start); |
1da177e4 LT |
253 | ret = -EIO; |
254 | goto unreg_stop; | |
255 | } | |
256 | ||
143a2e54 WVS |
257 | /* Check that the heartbeat value is within it's range ; |
258 | * if not reset to the default */ | |
0349a363 WVS |
259 | if (advwdt_set_heartbeat(timeout)) { |
260 | advwdt_set_heartbeat(WATCHDOG_TIMEOUT); | |
27c766aa | 261 | pr_info("timeout value must be 1<=x<=63, using %d\n", timeout); |
0349a363 WVS |
262 | } |
263 | ||
1da177e4 LT |
264 | ret = misc_register(&advwdt_miscdev); |
265 | if (ret != 0) { | |
27c766aa JP |
266 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
267 | WATCHDOG_MINOR, ret); | |
2e9c9cf4 | 268 | goto unreg_regions; |
1da177e4 | 269 | } |
27c766aa | 270 | pr_info("initialized. timeout=%d sec (nowayout=%d)\n", |
1da177e4 | 271 | timeout, nowayout); |
1da177e4 LT |
272 | out: |
273 | return ret; | |
1da177e4 LT |
274 | unreg_regions: |
275 | release_region(wdt_start, 1); | |
276 | unreg_stop: | |
277 | if (wdt_stop != wdt_start) | |
278 | release_region(wdt_stop, 1); | |
279 | goto out; | |
280 | } | |
281 | ||
4b12b896 | 282 | static int advwdt_remove(struct platform_device *dev) |
1da177e4 LT |
283 | { |
284 | misc_deregister(&advwdt_miscdev); | |
7944d3a5 WVS |
285 | release_region(wdt_start, 1); |
286 | if (wdt_stop != wdt_start) | |
287 | release_region(wdt_stop, 1); | |
c2bd11c7 WVS |
288 | |
289 | return 0; | |
290 | } | |
291 | ||
b6b4d9b8 | 292 | static void advwdt_shutdown(struct platform_device *dev) |
2e9c9cf4 WVS |
293 | { |
294 | /* Turn the WDT off if we have a soft shutdown */ | |
295 | advwdt_disable(); | |
296 | } | |
297 | ||
c2bd11c7 | 298 | static struct platform_driver advwdt_driver = { |
82268714 | 299 | .remove = advwdt_remove, |
2e9c9cf4 | 300 | .shutdown = advwdt_shutdown, |
c2bd11c7 | 301 | .driver = { |
c2bd11c7 WVS |
302 | .name = DRV_NAME, |
303 | }, | |
304 | }; | |
305 | ||
b6b4d9b8 | 306 | static int __init advwdt_init(void) |
c2bd11c7 WVS |
307 | { |
308 | int err; | |
309 | ||
27c766aa | 310 | pr_info("WDT driver for Advantech single board computer initialising\n"); |
c2bd11c7 | 311 | |
b6b4d9b8 AC |
312 | advwdt_platform_device = platform_device_register_simple(DRV_NAME, |
313 | -1, NULL, 0); | |
acaaaf62 JD |
314 | if (IS_ERR(advwdt_platform_device)) |
315 | return PTR_ERR(advwdt_platform_device); | |
316 | ||
317 | err = platform_driver_probe(&advwdt_driver, advwdt_probe); | |
318 | if (err) | |
319 | goto unreg_platform_device; | |
c2bd11c7 WVS |
320 | |
321 | return 0; | |
322 | ||
acaaaf62 JD |
323 | unreg_platform_device: |
324 | platform_device_unregister(advwdt_platform_device); | |
c2bd11c7 WVS |
325 | return err; |
326 | } | |
327 | ||
b6b4d9b8 | 328 | static void __exit advwdt_exit(void) |
c2bd11c7 WVS |
329 | { |
330 | platform_device_unregister(advwdt_platform_device); | |
331 | platform_driver_unregister(&advwdt_driver); | |
27c766aa | 332 | pr_info("Watchdog Module Unloaded\n"); |
1da177e4 LT |
333 | } |
334 | ||
335 | module_init(advwdt_init); | |
336 | module_exit(advwdt_exit); | |
337 | ||
338 | MODULE_LICENSE("GPL"); | |
339 | MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>"); | |
340 | MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver"); |