[WATCHDOG] struct file_operations should be const
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / advantechwdt.c
CommitLineData
1da177e4
LT
1/*
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 *
29fa0586
AC
9 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
10 * All Rights Reserved.
1da177e4
LT
11 *
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 *
29fa0586 21 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4
LT
22 *
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
31#include <linux/module.h>
32#include <linux/moduleparam.h>
33#include <linux/types.h>
34#include <linux/miscdevice.h>
35#include <linux/watchdog.h>
36#include <linux/fs.h>
37#include <linux/ioport.h>
c2bd11c7 38#include <linux/platform_device.h>
1da177e4 39#include <linux/init.h>
089ab079
WVS
40#include <linux/io.h>
41#include <linux/uaccess.h>
1da177e4 42
1da177e4
LT
43#include <asm/system.h>
44
1d747be6
WVS
45#define DRV_NAME "advantechwdt"
46#define PFX DRV_NAME ": "
1da177e4 47#define WATCHDOG_NAME "Advantech WDT"
1da177e4
LT
48#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
49
7944d3a5
WVS
50/* the watchdog platform device */
51static struct platform_device *advwdt_platform_device;
1da177e4
LT
52static 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);
b6b4d9b8
AC
76MODULE_PARM_DESC(timeout,
77 "Watchdog timeout in seconds. 1<= timeout <=63, default="
78 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
1da177e4 79
4bfdf378 80static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4 81module_param(nowayout, int, 0);
b6b4d9b8
AC
82MODULE_PARM_DESC(nowayout,
83 "Watchdog cannot be stopped once started (default="
84 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4
LT
85
86/*
1d747be6 87 * Watchdog Operations
1da177e4
LT
88 */
89
b6b4d9b8 90static void advwdt_ping(void)
1da177e4
LT
91{
92 /* Write a watchdog value */
93 outb_p(timeout, wdt_start);
94}
95
b6b4d9b8 96static void advwdt_disable(void)
1da177e4
LT
97{
98 inb_p(wdt_stop);
99}
100
b6b4d9b8 101static int advwdt_set_heartbeat(int t)
0349a363 102{
b6b4d9b8 103 if (t < 1 || t > 63)
0349a363 104 return -EINVAL;
0349a363
WVS
105 timeout = t;
106 return 0;
107}
108
1d747be6
WVS
109/*
110 * /dev/watchdog handling
111 */
112
b6b4d9b8
AC
113static ssize_t advwdt_write(struct file *file, const char __user *buf,
114 size_t count, loff_t *ppos)
1da177e4
LT
115{
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;
7944d3a5 124 if (get_user(c, buf + i))
1da177e4
LT
125 return -EFAULT;
126 if (c == 'V')
127 adv_expect_close = 42;
128 }
129 }
130 advwdt_ping();
131 }
132 return count;
133}
134
b6b4d9b8 135static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4
LT
136{
137 int new_timeout;
138 void __user *argp = (void __user *)arg;
139 int __user *p = argp;
140 static struct watchdog_info ident = {
141 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
142 .firmware_version = 1,
1d747be6 143 .identity = WATCHDOG_NAME,
1da177e4
LT
144 };
145
146 switch (cmd) {
147 case WDIOC_GETSUPPORT:
b6b4d9b8
AC
148 if (copy_to_user(argp, &ident, sizeof(ident)))
149 return -EFAULT;
150 break;
1da177e4
LT
151
152 case WDIOC_GETSTATUS:
153 case WDIOC_GETBOOTSTATUS:
b6b4d9b8 154 return put_user(0, p);
1da177e4 155
1da177e4
LT
156 case WDIOC_SETOPTIONS:
157 {
b6b4d9b8 158 int options, retval = -EINVAL;
1da177e4 159
b6b4d9b8
AC
160 if (get_user(options, p))
161 return -EFAULT;
162 if (options & WDIOS_DISABLECARD) {
163 advwdt_disable();
164 retval = 0;
165 }
166 if (options & WDIOS_ENABLECARD) {
167 advwdt_ping();
168 retval = 0;
169 }
170 return retval;
1da177e4 171 }
0c06090c
WVS
172 case WDIOC_KEEPALIVE:
173 advwdt_ping();
174 break;
175
176 case WDIOC_SETTIMEOUT:
177 if (get_user(new_timeout, p))
178 return -EFAULT;
179 if (advwdt_set_heartbeat(new_timeout))
180 return -EINVAL;
181 advwdt_ping();
182 /* Fall */
183 case WDIOC_GETTIMEOUT:
184 return put_user(timeout, p);
1da177e4 185 default:
b6b4d9b8 186 return -ENOTTY;
1da177e4
LT
187 }
188 return 0;
189}
190
b6b4d9b8 191static int advwdt_open(struct inode *inode, struct file *file)
1da177e4
LT
192{
193 if (test_and_set_bit(0, &advwdt_is_open))
194 return -EBUSY;
195 /*
196 * Activate
197 */
198
199 advwdt_ping();
200 return nonseekable_open(inode, file);
201}
202
7944d3a5 203static int advwdt_close(struct inode *inode, struct file *file)
1da177e4
LT
204{
205 if (adv_expect_close == 42) {
206 advwdt_disable();
207 } else {
b6b4d9b8
AC
208 printk(KERN_CRIT PFX
209 "Unexpected close, not stopping watchdog!\n");
1da177e4
LT
210 advwdt_ping();
211 }
212 clear_bit(0, &advwdt_is_open);
213 adv_expect_close = 0;
214 return 0;
215}
216
1da177e4
LT
217/*
218 * Kernel Interfaces
219 */
220
62322d25 221static const struct file_operations advwdt_fops = {
1da177e4
LT
222 .owner = THIS_MODULE,
223 .llseek = no_llseek,
224 .write = advwdt_write,
b6b4d9b8 225 .unlocked_ioctl = advwdt_ioctl,
1da177e4
LT
226 .open = advwdt_open,
227 .release = advwdt_close,
228};
229
230static struct miscdevice advwdt_miscdev = {
1d747be6
WVS
231 .minor = WATCHDOG_MINOR,
232 .name = "watchdog",
233 .fops = &advwdt_fops,
1da177e4
LT
234};
235
1d747be6
WVS
236/*
237 * Init & exit routines
238 */
239
b6b4d9b8 240static int __devinit advwdt_probe(struct platform_device *dev)
1da177e4
LT
241{
242 int ret;
243
1da177e4
LT
244 if (wdt_stop != wdt_start) {
245 if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
b6b4d9b8
AC
246 printk(KERN_ERR PFX
247 "I/O address 0x%04x already in use\n",
248 wdt_stop);
1da177e4
LT
249 ret = -EIO;
250 goto out;
251 }
252 }
253
254 if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
b6b4d9b8
AC
255 printk(KERN_ERR PFX
256 "I/O address 0x%04x already in use\n",
257 wdt_start);
1da177e4
LT
258 ret = -EIO;
259 goto unreg_stop;
260 }
261
0349a363
WVS
262 /* Check that the heartbeat value is within it's range ; if not reset to the default */
263 if (advwdt_set_heartbeat(timeout)) {
264 advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
b6b4d9b8
AC
265 printk(KERN_INFO PFX
266 "timeout value must be 1<=x<=63, using %d\n", timeout);
0349a363
WVS
267 }
268
1da177e4
LT
269 ret = misc_register(&advwdt_miscdev);
270 if (ret != 0) {
b6b4d9b8
AC
271 printk(KERN_ERR PFX
272 "cannot register miscdev on minor=%d (err=%d)\n",
273 WATCHDOG_MINOR, ret);
2e9c9cf4 274 goto unreg_regions;
1da177e4 275 }
b6b4d9b8 276 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
1da177e4 277 timeout, nowayout);
1da177e4
LT
278out:
279 return ret;
1da177e4
LT
280unreg_regions:
281 release_region(wdt_start, 1);
282unreg_stop:
283 if (wdt_stop != wdt_start)
284 release_region(wdt_stop, 1);
285 goto out;
286}
287
b6b4d9b8 288static int __devexit advwdt_remove(struct platform_device *dev)
1da177e4
LT
289{
290 misc_deregister(&advwdt_miscdev);
7944d3a5
WVS
291 release_region(wdt_start, 1);
292 if (wdt_stop != wdt_start)
293 release_region(wdt_stop, 1);
c2bd11c7
WVS
294
295 return 0;
296}
297
b6b4d9b8 298static void advwdt_shutdown(struct platform_device *dev)
2e9c9cf4
WVS
299{
300 /* Turn the WDT off if we have a soft shutdown */
301 advwdt_disable();
302}
303
c2bd11c7
WVS
304static struct platform_driver advwdt_driver = {
305 .probe = advwdt_probe,
306 .remove = __devexit_p(advwdt_remove),
2e9c9cf4 307 .shutdown = advwdt_shutdown,
c2bd11c7
WVS
308 .driver = {
309 .owner = THIS_MODULE,
310 .name = DRV_NAME,
311 },
312};
313
b6b4d9b8 314static int __init advwdt_init(void)
c2bd11c7
WVS
315{
316 int err;
317
7944d3a5
WVS
318 printk(KERN_INFO
319 "WDT driver for Advantech single board computer initialising.\n");
c2bd11c7
WVS
320
321 err = platform_driver_register(&advwdt_driver);
322 if (err)
323 return err;
324
b6b4d9b8
AC
325 advwdt_platform_device = platform_device_register_simple(DRV_NAME,
326 -1, NULL, 0);
c2bd11c7
WVS
327 if (IS_ERR(advwdt_platform_device)) {
328 err = PTR_ERR(advwdt_platform_device);
329 goto unreg_platform_driver;
330 }
331
332 return 0;
333
334unreg_platform_driver:
335 platform_driver_unregister(&advwdt_driver);
336 return err;
337}
338
b6b4d9b8 339static void __exit advwdt_exit(void)
c2bd11c7
WVS
340{
341 platform_device_unregister(advwdt_platform_device);
342 platform_driver_unregister(&advwdt_driver);
343 printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1da177e4
LT
344}
345
346module_init(advwdt_init);
347module_exit(advwdt_exit);
348
349MODULE_LICENSE("GPL");
350MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
351MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
352MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);