]>
Commit | Line | Data |
---|---|---|
c4c28335 GG |
1 | /* |
2 | * NANO7240 SBC Watchdog device driver | |
3 | * | |
4 | * Based on w83877f.c by Scott Jennings, | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation; | |
9 | * | |
10 | * Software distributed under the License is distributed on an "AS IS" | |
11 | * basis, WITHOUT WARRANTY OF ANY KIND, either express or | |
12 | * implied. See the License for the specific language governing | |
13 | * rights and limitations under the License. | |
14 | * | |
15 | * (c) Copyright 2007 Gilles GIGAN <gilles.gigan@jcu.edu.au> | |
16 | * | |
17 | */ | |
18 | ||
27c766aa JP |
19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
20 | ||
c4c28335 GG |
21 | #include <linux/fs.h> |
22 | #include <linux/init.h> | |
23 | #include <linux/ioport.h> | |
24 | #include <linux/jiffies.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/moduleparam.h> | |
27 | #include <linux/miscdevice.h> | |
28 | #include <linux/notifier.h> | |
29 | #include <linux/reboot.h> | |
30 | #include <linux/types.h> | |
31 | #include <linux/watchdog.h> | |
619a8a2b AC |
32 | #include <linux/io.h> |
33 | #include <linux/uaccess.h> | |
60063497 | 34 | #include <linux/atomic.h> |
c4c28335 | 35 | #include <asm/system.h> |
c4c28335 | 36 | |
c4c28335 GG |
37 | #define SBC7240_ENABLE_PORT 0x443 |
38 | #define SBC7240_DISABLE_PORT 0x043 | |
39 | #define SBC7240_SET_TIMEOUT_PORT SBC7240_ENABLE_PORT | |
40 | #define SBC7240_MAGIC_CHAR 'V' | |
41 | ||
42 | #define SBC7240_TIMEOUT 30 | |
43 | #define SBC7240_MAX_TIMEOUT 255 | |
44 | static int timeout = SBC7240_TIMEOUT; /* in seconds */ | |
45 | module_param(timeout, int, 0); | |
46 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=" | |
47 | __MODULE_STRING(SBC7240_MAX_TIMEOUT) ", default=" | |
48 | __MODULE_STRING(SBC7240_TIMEOUT) ")"); | |
49 | ||
86a1e189 WVS |
50 | static bool nowayout = WATCHDOG_NOWAYOUT; |
51 | module_param(nowayout, bool, 0); | |
c4c28335 GG |
52 | MODULE_PARM_DESC(nowayout, "Disable watchdog when closing device file"); |
53 | ||
54 | #define SBC7240_OPEN_STATUS_BIT 0 | |
55 | #define SBC7240_ENABLED_STATUS_BIT 1 | |
56 | #define SBC7240_EXPECT_CLOSE_STATUS_BIT 2 | |
57 | static unsigned long wdt_status; | |
58 | ||
59 | /* | |
60 | * Utility routines | |
61 | */ | |
62 | ||
63 | static void wdt_disable(void) | |
64 | { | |
65 | /* disable the watchdog */ | |
66 | if (test_and_clear_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status)) { | |
67 | inb_p(SBC7240_DISABLE_PORT); | |
27c766aa | 68 | pr_info("Watchdog timer is now disabled\n"); |
c4c28335 GG |
69 | } |
70 | } | |
71 | ||
72 | static void wdt_enable(void) | |
73 | { | |
74 | /* enable the watchdog */ | |
75 | if (!test_and_set_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status)) { | |
76 | inb_p(SBC7240_ENABLE_PORT); | |
27c766aa | 77 | pr_info("Watchdog timer is now enabled\n"); |
c4c28335 GG |
78 | } |
79 | } | |
80 | ||
81 | static int wdt_set_timeout(int t) | |
82 | { | |
83 | if (t < 1 || t > SBC7240_MAX_TIMEOUT) { | |
27c766aa | 84 | pr_err("timeout value must be 1<=x<=%d\n", SBC7240_MAX_TIMEOUT); |
c4c28335 GG |
85 | return -1; |
86 | } | |
87 | /* set the timeout */ | |
88 | outb_p((unsigned)t, SBC7240_SET_TIMEOUT_PORT); | |
89 | timeout = t; | |
27c766aa | 90 | pr_info("timeout set to %d seconds\n", t); |
c4c28335 GG |
91 | return 0; |
92 | } | |
93 | ||
94 | /* Whack the dog */ | |
95 | static inline void wdt_keepalive(void) | |
96 | { | |
97 | if (test_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status)) | |
98 | inb_p(SBC7240_ENABLE_PORT); | |
99 | } | |
100 | ||
101 | /* | |
102 | * /dev/watchdog handling | |
103 | */ | |
104 | static ssize_t fop_write(struct file *file, const char __user *buf, | |
105 | size_t count, loff_t *ppos) | |
106 | { | |
107 | size_t i; | |
108 | char c; | |
109 | ||
110 | if (count) { | |
111 | if (!nowayout) { | |
112 | clear_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT, | |
113 | &wdt_status); | |
114 | ||
115 | /* is there a magic char ? */ | |
116 | for (i = 0; i != count; i++) { | |
117 | if (get_user(c, buf + i)) | |
118 | return -EFAULT; | |
119 | if (c == SBC7240_MAGIC_CHAR) { | |
120 | set_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT, | |
121 | &wdt_status); | |
122 | break; | |
123 | } | |
124 | } | |
125 | } | |
126 | ||
127 | wdt_keepalive(); | |
128 | } | |
129 | ||
130 | return count; | |
131 | } | |
132 | ||
133 | static int fop_open(struct inode *inode, struct file *file) | |
134 | { | |
135 | if (test_and_set_bit(SBC7240_OPEN_STATUS_BIT, &wdt_status)) | |
136 | return -EBUSY; | |
137 | ||
138 | wdt_enable(); | |
139 | ||
140 | return nonseekable_open(inode, file); | |
141 | } | |
142 | ||
143 | static int fop_close(struct inode *inode, struct file *file) | |
144 | { | |
145 | if (test_and_clear_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT, &wdt_status) | |
146 | || !nowayout) { | |
147 | wdt_disable(); | |
148 | } else { | |
27c766aa | 149 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
c4c28335 GG |
150 | wdt_keepalive(); |
151 | } | |
152 | ||
153 | clear_bit(SBC7240_OPEN_STATUS_BIT, &wdt_status); | |
154 | return 0; | |
155 | } | |
156 | ||
619a8a2b | 157 | static const struct watchdog_info ident = { |
c4c28335 GG |
158 | .options = WDIOF_KEEPALIVEPING| |
159 | WDIOF_SETTIMEOUT| | |
160 | WDIOF_MAGICCLOSE, | |
161 | .firmware_version = 1, | |
162 | .identity = "SBC7240", | |
163 | }; | |
164 | ||
165 | ||
619a8a2b | 166 | static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
c4c28335 GG |
167 | { |
168 | switch (cmd) { | |
169 | case WDIOC_GETSUPPORT: | |
619a8a2b AC |
170 | return copy_to_user((void __user *)arg, &ident, sizeof(ident)) |
171 | ? -EFAULT : 0; | |
c4c28335 GG |
172 | case WDIOC_GETSTATUS: |
173 | case WDIOC_GETBOOTSTATUS: | |
174 | return put_user(0, (int __user *)arg); | |
0c06090c WVS |
175 | case WDIOC_SETOPTIONS: |
176 | { | |
177 | int options; | |
178 | int retval = -EINVAL; | |
c4c28335 | 179 | |
0c06090c WVS |
180 | if (get_user(options, (int __user *)arg)) |
181 | return -EFAULT; | |
c4c28335 | 182 | |
0c06090c WVS |
183 | if (options & WDIOS_DISABLECARD) { |
184 | wdt_disable(); | |
185 | retval = 0; | |
186 | } | |
c4c28335 | 187 | |
0c06090c WVS |
188 | if (options & WDIOS_ENABLECARD) { |
189 | wdt_enable(); | |
190 | retval = 0; | |
c4c28335 | 191 | } |
c4c28335 | 192 | |
0c06090c WVS |
193 | return retval; |
194 | } | |
195 | case WDIOC_KEEPALIVE: | |
196 | wdt_keepalive(); | |
197 | return 0; | |
198 | case WDIOC_SETTIMEOUT: | |
199 | { | |
200 | int new_timeout; | |
c4c28335 | 201 | |
0c06090c WVS |
202 | if (get_user(new_timeout, (int __user *)arg)) |
203 | return -EFAULT; | |
c4c28335 | 204 | |
0c06090c WVS |
205 | if (wdt_set_timeout(new_timeout)) |
206 | return -EINVAL; | |
207 | ||
208 | /* Fall through */ | |
209 | } | |
c4c28335 GG |
210 | case WDIOC_GETTIMEOUT: |
211 | return put_user(timeout, (int __user *)arg); | |
212 | default: | |
213 | return -ENOTTY; | |
214 | } | |
215 | } | |
216 | ||
217 | static const struct file_operations wdt_fops = { | |
218 | .owner = THIS_MODULE, | |
219 | .llseek = no_llseek, | |
220 | .write = fop_write, | |
221 | .open = fop_open, | |
222 | .release = fop_close, | |
619a8a2b | 223 | .unlocked_ioctl = fop_ioctl, |
c4c28335 GG |
224 | }; |
225 | ||
226 | static struct miscdevice wdt_miscdev = { | |
227 | .minor = WATCHDOG_MINOR, | |
228 | .name = "watchdog", | |
229 | .fops = &wdt_fops, | |
230 | }; | |
231 | ||
232 | /* | |
233 | * Notifier for system down | |
234 | */ | |
235 | ||
236 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | |
237 | void *unused) | |
238 | { | |
239 | if (code == SYS_DOWN || code == SYS_HALT) | |
240 | wdt_disable(); | |
241 | return NOTIFY_DONE; | |
242 | } | |
243 | ||
244 | static struct notifier_block wdt_notifier = { | |
245 | .notifier_call = wdt_notify_sys, | |
246 | }; | |
247 | ||
248 | static void __exit sbc7240_wdt_unload(void) | |
249 | { | |
27c766aa | 250 | pr_info("Removing watchdog\n"); |
c4c28335 GG |
251 | misc_deregister(&wdt_miscdev); |
252 | ||
253 | unregister_reboot_notifier(&wdt_notifier); | |
254 | release_region(SBC7240_ENABLE_PORT, 1); | |
255 | } | |
256 | ||
257 | static int __init sbc7240_wdt_init(void) | |
258 | { | |
259 | int rc = -EBUSY; | |
260 | ||
261 | if (!request_region(SBC7240_ENABLE_PORT, 1, "SBC7240 WDT")) { | |
27c766aa | 262 | pr_err("I/O address 0x%04x already in use\n", |
c4c28335 GG |
263 | SBC7240_ENABLE_PORT); |
264 | rc = -EIO; | |
265 | goto err_out; | |
266 | } | |
267 | ||
268 | /* The IO port 0x043 used to disable the watchdog | |
269 | * is already claimed by the system timer, so we | |
25985edc | 270 | * can't request_region() it ...*/ |
c4c28335 GG |
271 | |
272 | if (timeout < 1 || timeout > SBC7240_MAX_TIMEOUT) { | |
273 | timeout = SBC7240_TIMEOUT; | |
27c766aa JP |
274 | pr_info("timeout value must be 1<=x<=%d, using %d\n", |
275 | SBC7240_MAX_TIMEOUT, timeout); | |
c4c28335 GG |
276 | } |
277 | wdt_set_timeout(timeout); | |
278 | wdt_disable(); | |
279 | ||
280 | rc = register_reboot_notifier(&wdt_notifier); | |
281 | if (rc) { | |
27c766aa | 282 | pr_err("cannot register reboot notifier (err=%d)\n", rc); |
c4c28335 GG |
283 | goto err_out_region; |
284 | } | |
285 | ||
286 | rc = misc_register(&wdt_miscdev); | |
287 | if (rc) { | |
27c766aa | 288 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
c4c28335 GG |
289 | wdt_miscdev.minor, rc); |
290 | goto err_out_reboot_notifier; | |
291 | } | |
292 | ||
27c766aa JP |
293 | pr_info("Watchdog driver for SBC7240 initialised (nowayout=%d)\n", |
294 | nowayout); | |
c4c28335 GG |
295 | |
296 | return 0; | |
297 | ||
298 | err_out_reboot_notifier: | |
299 | unregister_reboot_notifier(&wdt_notifier); | |
300 | err_out_region: | |
301 | release_region(SBC7240_ENABLE_PORT, 1); | |
302 | err_out: | |
303 | return rc; | |
304 | } | |
305 | ||
306 | module_init(sbc7240_wdt_init); | |
307 | module_exit(sbc7240_wdt_unload); | |
308 | ||
309 | MODULE_AUTHOR("Gilles Gigan"); | |
310 | MODULE_DESCRIPTION("Watchdog device driver for single board" | |
311 | " computers EPIC Nano 7240 from iEi"); | |
312 | MODULE_LICENSE("GPL"); | |
313 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
314 |