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1da177e4 LT |
1 | /* |
2 | * National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver | |
3 | * (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>, | |
4 | * All Rights Reserved. | |
5 | * Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * The author(s) of this software shall not be held liable for damages | |
13 | * of any nature resulting due to the use of this software. This | |
14 | * software is provided AS-IS with no warranties. | |
15 | * | |
16 | * Changelog: | |
17 | * 20020220 Zwane Mwaikambo Code based on datasheet, no hardware. | |
18 | * 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik and Alan Cox. | |
19 | * 20020222 Zwane Mwaikambo Added probing. | |
20 | * 20020225 Zwane Mwaikambo Added ISAPNP support. | |
21 | * 20020412 Rob Radez Broke out start/stop functions | |
22 | * <rob@osinvestor.com> Return proper status instead of temperature warning | |
23 | * Add WDIOC_GETBOOTSTATUS and WDIOC_SETOPTIONS ioctls | |
24 | * Fix CONFIG_WATCHDOG_NOWAYOUT | |
25 | * 20020530 Joel Becker Add Matt Domsch's nowayout module option | |
26 | * 20030116 Adam Belay Updated to the latest pnp code | |
27 | * | |
28 | */ | |
29 | ||
1da177e4 LT |
30 | #include <linux/module.h> |
31 | #include <linux/moduleparam.h> | |
32 | #include <linux/miscdevice.h> | |
33 | #include <linux/watchdog.h> | |
34 | #include <linux/ioport.h> | |
35 | #include <linux/spinlock.h> | |
36 | #include <linux/notifier.h> | |
37 | #include <linux/reboot.h> | |
38 | #include <linux/init.h> | |
39 | #include <linux/pnp.h> | |
40 | #include <linux/fs.h> | |
1da177e4 LT |
41 | |
42 | #include <asm/semaphore.h> | |
43 | #include <asm/io.h> | |
44 | #include <asm/uaccess.h> | |
45 | ||
46 | #define SC1200_MODULE_VER "build 20020303" | |
47 | #define SC1200_MODULE_NAME "sc1200wdt" | |
48 | #define PFX SC1200_MODULE_NAME ": " | |
49 | ||
50 | #define MAX_TIMEOUT 255 /* 255 minutes */ | |
51 | #define PMIR (io) /* Power Management Index Register */ | |
52 | #define PMDR (io+1) /* Power Management Data Register */ | |
53 | ||
54 | /* Data Register indexes */ | |
55 | #define FER1 0x00 /* Function enable register 1 */ | |
56 | #define FER2 0x01 /* Function enable register 2 */ | |
57 | #define PMC1 0x02 /* Power Management Ctrl 1 */ | |
58 | #define PMC2 0x03 /* Power Management Ctrl 2 */ | |
59 | #define PMC3 0x04 /* Power Management Ctrl 3 */ | |
60 | #define WDTO 0x05 /* Watchdog timeout register */ | |
61 | #define WDCF 0x06 /* Watchdog config register */ | |
62 | #define WDST 0x07 /* Watchdog status register */ | |
63 | ||
64 | /* WDCF bitfields - which devices assert WDO */ | |
65 | #define KBC_IRQ 0x01 /* Keyboard Controller */ | |
66 | #define MSE_IRQ 0x02 /* Mouse */ | |
67 | #define UART1_IRQ 0x03 /* Serial0 */ | |
68 | #define UART2_IRQ 0x04 /* Serial1 */ | |
69 | /* 5 -7 are reserved */ | |
70 | ||
71 | static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER; | |
72 | static int timeout = 1; | |
73 | static int io = -1; | |
74 | static int io_len = 2; /* for non plug and play */ | |
75 | static struct semaphore open_sem; | |
76 | static char expect_close; | |
c7dfd0cc | 77 | static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */ |
1da177e4 LT |
78 | |
79 | #if defined CONFIG_PNP | |
80 | static int isapnp = 1; | |
81 | static struct pnp_dev *wdt_dev; | |
82 | ||
83 | module_param(isapnp, int, 0); | |
84 | MODULE_PARM_DESC(isapnp, "When set to 0 driver ISA PnP support will be disabled"); | |
85 | #endif | |
86 | ||
87 | module_param(io, int, 0); | |
88 | MODULE_PARM_DESC(io, "io port"); | |
89 | module_param(timeout, int, 0); | |
90 | MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1"); | |
91 | ||
4bfdf378 | 92 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 93 | module_param(nowayout, int, 0); |
bffda5c8 | 94 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
1da177e4 LT |
95 | |
96 | ||
97 | ||
98 | /* Read from Data Register */ | |
99 | static inline void sc1200wdt_read_data(unsigned char index, unsigned char *data) | |
100 | { | |
101 | spin_lock(&sc1200wdt_lock); | |
102 | outb_p(index, PMIR); | |
103 | *data = inb(PMDR); | |
104 | spin_unlock(&sc1200wdt_lock); | |
105 | } | |
106 | ||
107 | ||
108 | /* Write to Data Register */ | |
109 | static inline void sc1200wdt_write_data(unsigned char index, unsigned char data) | |
110 | { | |
111 | spin_lock(&sc1200wdt_lock); | |
112 | outb_p(index, PMIR); | |
113 | outb(data, PMDR); | |
114 | spin_unlock(&sc1200wdt_lock); | |
115 | } | |
116 | ||
117 | ||
118 | static void sc1200wdt_start(void) | |
119 | { | |
120 | unsigned char reg; | |
121 | ||
122 | sc1200wdt_read_data(WDCF, ®); | |
123 | /* assert WDO when any of the following interrupts are triggered too */ | |
124 | reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ); | |
125 | sc1200wdt_write_data(WDCF, reg); | |
126 | /* set the timeout and get the ball rolling */ | |
127 | sc1200wdt_write_data(WDTO, timeout); | |
128 | } | |
129 | ||
130 | ||
131 | static void sc1200wdt_stop(void) | |
132 | { | |
133 | sc1200wdt_write_data(WDTO, 0); | |
134 | } | |
135 | ||
136 | ||
137 | /* This returns the status of the WDO signal, inactive high. */ | |
138 | static inline int sc1200wdt_status(void) | |
139 | { | |
140 | unsigned char ret; | |
141 | ||
142 | sc1200wdt_read_data(WDST, &ret); | |
143 | /* If the bit is inactive, the watchdog is enabled, so return | |
144 | * KEEPALIVEPING which is a bit of a kludge because there's nothing | |
145 | * else for enabled/disabled status | |
146 | */ | |
147 | return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING; /* bits 1 - 7 are undefined */ | |
148 | } | |
149 | ||
150 | ||
151 | static int sc1200wdt_open(struct inode *inode, struct file *file) | |
152 | { | |
1da177e4 LT |
153 | /* allow one at a time */ |
154 | if (down_trylock(&open_sem)) | |
155 | return -EBUSY; | |
156 | ||
157 | if (timeout > MAX_TIMEOUT) | |
158 | timeout = MAX_TIMEOUT; | |
159 | ||
160 | sc1200wdt_start(); | |
161 | printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout); | |
162 | ||
6abe78bf | 163 | return nonseekable_open(inode, file); |
1da177e4 LT |
164 | } |
165 | ||
166 | ||
167 | static int sc1200wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
168 | { | |
169 | int new_timeout; | |
170 | void __user *argp = (void __user *)arg; | |
171 | int __user *p = argp; | |
172 | static struct watchdog_info ident = { | |
173 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
174 | .firmware_version = 0, | |
175 | .identity = "PC87307/PC97307", | |
176 | }; | |
177 | ||
178 | switch (cmd) { | |
179 | default: | |
795b89d2 | 180 | return -ENOTTY; |
1da177e4 LT |
181 | |
182 | case WDIOC_GETSUPPORT: | |
183 | if (copy_to_user(argp, &ident, sizeof ident)) | |
184 | return -EFAULT; | |
185 | return 0; | |
186 | ||
187 | case WDIOC_GETSTATUS: | |
188 | return put_user(sc1200wdt_status(), p); | |
189 | ||
190 | case WDIOC_GETBOOTSTATUS: | |
191 | return put_user(0, p); | |
192 | ||
193 | case WDIOC_KEEPALIVE: | |
194 | sc1200wdt_write_data(WDTO, timeout); | |
195 | return 0; | |
196 | ||
197 | case WDIOC_SETTIMEOUT: | |
198 | if (get_user(new_timeout, p)) | |
199 | return -EFAULT; | |
200 | ||
201 | /* the API states this is given in secs */ | |
202 | new_timeout /= 60; | |
203 | if (new_timeout < 0 || new_timeout > MAX_TIMEOUT) | |
204 | return -EINVAL; | |
205 | ||
206 | timeout = new_timeout; | |
207 | sc1200wdt_write_data(WDTO, timeout); | |
208 | /* fall through and return the new timeout */ | |
209 | ||
210 | case WDIOC_GETTIMEOUT: | |
211 | return put_user(timeout * 60, p); | |
212 | ||
213 | case WDIOC_SETOPTIONS: | |
214 | { | |
215 | int options, retval = -EINVAL; | |
216 | ||
217 | if (get_user(options, p)) | |
218 | return -EFAULT; | |
219 | ||
220 | if (options & WDIOS_DISABLECARD) { | |
221 | sc1200wdt_stop(); | |
222 | retval = 0; | |
223 | } | |
224 | ||
225 | if (options & WDIOS_ENABLECARD) { | |
226 | sc1200wdt_start(); | |
227 | retval = 0; | |
228 | } | |
229 | ||
230 | return retval; | |
231 | } | |
232 | } | |
233 | } | |
234 | ||
235 | ||
236 | static int sc1200wdt_release(struct inode *inode, struct file *file) | |
237 | { | |
238 | if (expect_close == 42) { | |
239 | sc1200wdt_stop(); | |
240 | printk(KERN_INFO PFX "Watchdog disabled\n"); | |
241 | } else { | |
242 | sc1200wdt_write_data(WDTO, timeout); | |
243 | printk(KERN_CRIT PFX "Unexpected close!, timeout = %d min(s)\n", timeout); | |
244 | } | |
245 | up(&open_sem); | |
246 | expect_close = 0; | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
251 | ||
252 | static ssize_t sc1200wdt_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) | |
253 | { | |
254 | if (len) { | |
255 | if (!nowayout) { | |
256 | size_t i; | |
257 | ||
258 | expect_close = 0; | |
259 | ||
260 | for (i = 0; i != len; i++) { | |
261 | char c; | |
262 | ||
263 | if (get_user(c, data+i)) | |
264 | return -EFAULT; | |
265 | if (c == 'V') | |
266 | expect_close = 42; | |
267 | } | |
268 | } | |
269 | ||
270 | sc1200wdt_write_data(WDTO, timeout); | |
271 | return len; | |
272 | } | |
273 | ||
274 | return 0; | |
275 | } | |
276 | ||
277 | ||
278 | static int sc1200wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) | |
279 | { | |
280 | if (code == SYS_DOWN || code == SYS_HALT) | |
281 | sc1200wdt_stop(); | |
282 | ||
283 | return NOTIFY_DONE; | |
284 | } | |
285 | ||
286 | ||
287 | static struct notifier_block sc1200wdt_notifier = | |
288 | { | |
289 | .notifier_call = sc1200wdt_notify_sys, | |
290 | }; | |
291 | ||
62322d25 | 292 | static const struct file_operations sc1200wdt_fops = |
1da177e4 LT |
293 | { |
294 | .owner = THIS_MODULE, | |
295 | .llseek = no_llseek, | |
296 | .write = sc1200wdt_write, | |
297 | .ioctl = sc1200wdt_ioctl, | |
298 | .open = sc1200wdt_open, | |
299 | .release = sc1200wdt_release, | |
300 | }; | |
301 | ||
302 | static struct miscdevice sc1200wdt_miscdev = | |
303 | { | |
304 | .minor = WATCHDOG_MINOR, | |
305 | .name = "watchdog", | |
306 | .fops = &sc1200wdt_fops, | |
307 | }; | |
308 | ||
309 | ||
310 | static int __init sc1200wdt_probe(void) | |
311 | { | |
312 | /* The probe works by reading the PMC3 register's default value of 0x0e | |
313 | * there is one caveat, if the device disables the parallel port or any | |
314 | * of the UARTs we won't be able to detect it. | |
315 | * Nb. This could be done with accuracy by reading the SID registers, but | |
316 | * we don't have access to those io regions. | |
317 | */ | |
318 | ||
319 | unsigned char reg; | |
320 | ||
321 | sc1200wdt_read_data(PMC3, ®); | |
322 | reg &= 0x0f; /* we don't want the UART busy bits */ | |
323 | return (reg == 0x0e) ? 0 : -ENODEV; | |
324 | } | |
325 | ||
326 | ||
327 | #if defined CONFIG_PNP | |
328 | ||
329 | static struct pnp_device_id scl200wdt_pnp_devices[] = { | |
330 | /* National Semiconductor PC87307/PC97307 watchdog component */ | |
331 | {.id = "NSC0800", .driver_data = 0}, | |
332 | {.id = ""}, | |
333 | }; | |
334 | ||
335 | static int scl200wdt_pnp_probe(struct pnp_dev * dev, const struct pnp_device_id *dev_id) | |
336 | { | |
337 | /* this driver only supports one card at a time */ | |
338 | if (wdt_dev || !isapnp) | |
339 | return -EBUSY; | |
340 | ||
341 | wdt_dev = dev; | |
342 | io = pnp_port_start(wdt_dev, 0); | |
343 | io_len = pnp_port_len(wdt_dev, 0); | |
344 | ||
345 | if (!request_region(io, io_len, SC1200_MODULE_NAME)) { | |
346 | printk(KERN_ERR PFX "Unable to register IO port %#x\n", io); | |
347 | return -EBUSY; | |
348 | } | |
349 | ||
350 | printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n", io, io_len); | |
351 | return 0; | |
352 | } | |
353 | ||
354 | static void scl200wdt_pnp_remove(struct pnp_dev * dev) | |
355 | { | |
356 | if (wdt_dev){ | |
357 | release_region(io, io_len); | |
358 | wdt_dev = NULL; | |
359 | } | |
360 | } | |
361 | ||
362 | static struct pnp_driver scl200wdt_pnp_driver = { | |
363 | .name = "scl200wdt", | |
364 | .id_table = scl200wdt_pnp_devices, | |
365 | .probe = scl200wdt_pnp_probe, | |
366 | .remove = scl200wdt_pnp_remove, | |
367 | }; | |
368 | ||
369 | #endif /* CONFIG_PNP */ | |
370 | ||
371 | ||
372 | static int __init sc1200wdt_init(void) | |
373 | { | |
374 | int ret; | |
375 | ||
7071e522 | 376 | printk("%s\n", banner); |
1da177e4 | 377 | |
1da177e4 LT |
378 | sema_init(&open_sem, 1); |
379 | ||
380 | #if defined CONFIG_PNP | |
381 | if (isapnp) { | |
382 | ret = pnp_register_driver(&scl200wdt_pnp_driver); | |
383 | if (ret) | |
384 | goto out_clean; | |
385 | } | |
386 | #endif | |
387 | ||
388 | if (io == -1) { | |
389 | printk(KERN_ERR PFX "io parameter must be specified\n"); | |
390 | ret = -EINVAL; | |
150ed8ed | 391 | goto out_pnp; |
1da177e4 LT |
392 | } |
393 | ||
394 | #if defined CONFIG_PNP | |
395 | /* now that the user has specified an IO port and we haven't detected | |
396 | * any devices, disable pnp support */ | |
397 | isapnp = 0; | |
398 | pnp_unregister_driver(&scl200wdt_pnp_driver); | |
399 | #endif | |
400 | ||
401 | if (!request_region(io, io_len, SC1200_MODULE_NAME)) { | |
402 | printk(KERN_ERR PFX "Unable to register IO port %#x\n", io); | |
403 | ret = -EBUSY; | |
150ed8ed | 404 | goto out_pnp; |
1da177e4 LT |
405 | } |
406 | ||
407 | ret = sc1200wdt_probe(); | |
408 | if (ret) | |
409 | goto out_io; | |
410 | ||
411 | ret = register_reboot_notifier(&sc1200wdt_notifier); | |
412 | if (ret) { | |
413 | printk(KERN_ERR PFX "Unable to register reboot notifier err = %d\n", ret); | |
414 | goto out_io; | |
415 | } | |
416 | ||
417 | ret = misc_register(&sc1200wdt_miscdev); | |
418 | if (ret) { | |
419 | printk(KERN_ERR PFX "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR); | |
420 | goto out_rbt; | |
421 | } | |
422 | ||
423 | /* ret = 0 */ | |
424 | ||
425 | out_clean: | |
426 | return ret; | |
427 | ||
428 | out_rbt: | |
429 | unregister_reboot_notifier(&sc1200wdt_notifier); | |
430 | ||
431 | out_io: | |
432 | release_region(io, io_len); | |
433 | ||
150ed8ed AM |
434 | out_pnp: |
435 | #if defined CONFIG_PNP | |
436 | if (isapnp) | |
437 | pnp_unregister_driver(&scl200wdt_pnp_driver); | |
438 | #endif | |
1da177e4 LT |
439 | goto out_clean; |
440 | } | |
441 | ||
442 | ||
443 | static void __exit sc1200wdt_exit(void) | |
444 | { | |
445 | misc_deregister(&sc1200wdt_miscdev); | |
446 | unregister_reboot_notifier(&sc1200wdt_notifier); | |
447 | ||
448 | #if defined CONFIG_PNP | |
449 | if(isapnp) | |
450 | pnp_unregister_driver(&scl200wdt_pnp_driver); | |
451 | else | |
452 | #endif | |
453 | release_region(io, io_len); | |
454 | } | |
455 | ||
456 | module_init(sc1200wdt_init); | |
457 | module_exit(sc1200wdt_exit); | |
458 | ||
459 | MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>"); | |
460 | MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component"); | |
461 | MODULE_LICENSE("GPL"); | |
462 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |