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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 |
19 | * and Alan Cox. |
20 | * 20020222 Zwane Mwaikambo Added probing. |
21 | * 20020225 Zwane Mwaikambo Added ISAPNP support. |
22 | * 20020412 Rob Radez Broke out start/stop functions |
23 | * <rob@osinvestor.com> Return proper status instead of |
24 | * temperature warning |
25 | * Add WDIOC_GETBOOTSTATUS and |
26 | * WDIOC_SETOPTIONS ioctls |
27 | * Fix CONFIG_WATCHDOG_NOWAYOUT |
28 | * 20020530 Joel Becker Add Matt Domsch's nowayout module |
29 | * option |
30 | * 20030116 Adam Belay Updated to the latest pnp code |
31 | * |
32 | */ |
33 | |
34 | #include <linux/module.h> |
35 | #include <linux/moduleparam.h> |
36 | #include <linux/miscdevice.h> |
37 | #include <linux/watchdog.h> |
38 | #include <linux/ioport.h> |
39 | #include <linux/spinlock.h> |
40 | #include <linux/notifier.h> |
41 | #include <linux/reboot.h> |
42 | #include <linux/init.h> |
43 | #include <linux/pnp.h> |
44 | #include <linux/fs.h> |
45 | #include <linux/semaphore.h> |
46 | #include <linux/io.h> |
47 | #include <linux/uaccess.h> |
48 | |
49 | #define SC1200_MODULE_VER "build 20020303" |
50 | #define SC1200_MODULE_NAME "sc1200wdt" |
51 | #define PFX SC1200_MODULE_NAME ": " |
52 | |
53 | #define MAX_TIMEOUT 255 /* 255 minutes */ |
54 | #define PMIR (io) /* Power Management Index Register */ |
55 | #define PMDR (io+1) /* Power Management Data Register */ |
56 | |
57 | /* Data Register indexes */ |
58 | #define FER1 0x00 /* Function enable register 1 */ |
59 | #define FER2 0x01 /* Function enable register 2 */ |
60 | #define PMC1 0x02 /* Power Management Ctrl 1 */ |
61 | #define PMC2 0x03 /* Power Management Ctrl 2 */ |
62 | #define PMC3 0x04 /* Power Management Ctrl 3 */ |
63 | #define WDTO 0x05 /* Watchdog timeout register */ |
64 | #define WDCF 0x06 /* Watchdog config register */ |
65 | #define WDST 0x07 /* Watchdog status register */ |
66 | |
67 | /* WDCF bitfields - which devices assert WDO */ |
68 | #define KBC_IRQ 0x01 /* Keyboard Controller */ |
69 | #define MSE_IRQ 0x02 /* Mouse */ |
70 | #define UART1_IRQ 0x03 /* Serial0 */ |
71 | #define UART2_IRQ 0x04 /* Serial1 */ |
72 | /* 5 -7 are reserved */ |
73 | |
74 | static char banner[] __initdata = PFX SC1200_MODULE_VER; |
75 | static int timeout = 1; |
76 | static int io = -1; |
77 | static int io_len = 2; /* for non plug and play */ |
78 | static unsigned long open_flag; |
79 | static char expect_close; |
80 | static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */ |
81 | |
82 | #if defined CONFIG_PNP |
83 | static int isapnp = 1; |
84 | static struct pnp_dev *wdt_dev; |
85 | |
86 | module_param(isapnp, int, 0); |
87 | MODULE_PARM_DESC(isapnp, |
88 | "When set to 0 driver ISA PnP support will be disabled"); |
89 | #endif |
90 | |
91 | module_param(io, int, 0); |
92 | MODULE_PARM_DESC(io, "io port"); |
93 | module_param(timeout, int, 0); |
94 | MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1"); |
95 | |
96 | static int nowayout = WATCHDOG_NOWAYOUT; |
97 | module_param(nowayout, int, 0); |
98 | MODULE_PARM_DESC(nowayout, |
99 | "Watchdog cannot be stopped once started (default=" |
100 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
101 | |
102 | |
103 | |
104 | /* Read from Data Register */ |
105 | static inline void __sc1200wdt_read_data(unsigned char index, |
106 | unsigned char *data) |
107 | { |
108 | outb_p(index, PMIR); |
109 | *data = inb(PMDR); |
110 | } |
111 | |
112 | static void sc1200wdt_read_data(unsigned char index, unsigned char *data) |
113 | { |
114 | spin_lock(&sc1200wdt_lock); |
115 | __sc1200wdt_read_data(index, data); |
116 | spin_unlock(&sc1200wdt_lock); |
117 | } |
118 | |
119 | /* Write to Data Register */ |
120 | static inline void __sc1200wdt_write_data(unsigned char index, |
121 | unsigned char data) |
122 | { |
123 | outb_p(index, PMIR); |
124 | outb(data, PMDR); |
125 | } |
126 | |
127 | static inline void sc1200wdt_write_data(unsigned char index, |
128 | unsigned char data) |
129 | { |
130 | spin_lock(&sc1200wdt_lock); |
131 | __sc1200wdt_write_data(index, data); |
132 | spin_unlock(&sc1200wdt_lock); |
133 | } |
134 | |
135 | |
136 | static void sc1200wdt_start(void) |
137 | { |
138 | unsigned char reg; |
139 | spin_lock(&sc1200wdt_lock); |
140 | |
141 | __sc1200wdt_read_data(WDCF, ®); |
142 | /* assert WDO when any of the following interrupts are triggered too */ |
143 | reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ); |
144 | __sc1200wdt_write_data(WDCF, reg); |
145 | /* set the timeout and get the ball rolling */ |
146 | __sc1200wdt_write_data(WDTO, timeout); |
147 | |
148 | spin_unlock(&sc1200wdt_lock); |
149 | } |
150 | |
151 | static void sc1200wdt_stop(void) |
152 | { |
153 | sc1200wdt_write_data(WDTO, 0); |
154 | } |
155 | |
156 | /* This returns the status of the WDO signal, inactive high. */ |
157 | static inline int sc1200wdt_status(void) |
158 | { |
159 | unsigned char ret; |
160 | |
161 | sc1200wdt_read_data(WDST, &ret); |
162 | /* If the bit is inactive, the watchdog is enabled, so return |
163 | * KEEPALIVEPING which is a bit of a kludge because there's nothing |
164 | * else for enabled/disabled status |
165 | */ |
166 | return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING; |
167 | } |
168 | |
169 | static int sc1200wdt_open(struct inode *inode, struct file *file) |
170 | { |
171 | /* allow one at a time */ |
172 | if (test_and_set_bit(0, &open_flag)) |
173 | return -EBUSY; |
174 | |
175 | if (timeout > MAX_TIMEOUT) |
176 | timeout = MAX_TIMEOUT; |
177 | |
178 | sc1200wdt_start(); |
179 | printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout); |
180 | |
181 | return nonseekable_open(inode, file); |
182 | } |
183 | |
184 | |
185 | static long sc1200wdt_ioctl(struct file *file, unsigned int cmd, |
186 | unsigned long arg) |
187 | { |
188 | int new_timeout; |
189 | void __user *argp = (void __user *)arg; |
190 | int __user *p = argp; |
191 | static const struct watchdog_info ident = { |
192 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | |
193 | WDIOF_MAGICCLOSE, |
194 | .firmware_version = 0, |
195 | .identity = "PC87307/PC97307", |
196 | }; |
197 | |
198 | switch (cmd) { |
199 | case WDIOC_GETSUPPORT: |
200 | if (copy_to_user(argp, &ident, sizeof(ident))) |
201 | return -EFAULT; |
202 | return 0; |
203 | |
204 | case WDIOC_GETSTATUS: |
205 | return put_user(sc1200wdt_status(), p); |
206 | |
207 | case WDIOC_GETBOOTSTATUS: |
208 | return put_user(0, p); |
209 | |
210 | case WDIOC_SETOPTIONS: |
211 | { |
212 | int options, retval = -EINVAL; |
213 | |
214 | if (get_user(options, p)) |
215 | return -EFAULT; |
216 | |
217 | if (options & WDIOS_DISABLECARD) { |
218 | sc1200wdt_stop(); |
219 | retval = 0; |
220 | } |
221 | |
222 | if (options & WDIOS_ENABLECARD) { |
223 | sc1200wdt_start(); |
224 | retval = 0; |
225 | } |
226 | |
227 | return retval; |
228 | } |
229 | case WDIOC_KEEPALIVE: |
230 | sc1200wdt_write_data(WDTO, timeout); |
231 | return 0; |
232 | |
233 | case WDIOC_SETTIMEOUT: |
234 | if (get_user(new_timeout, p)) |
235 | return -EFAULT; |
236 | /* the API states this is given in secs */ |
237 | new_timeout /= 60; |
238 | if (new_timeout < 0 || new_timeout > MAX_TIMEOUT) |
239 | return -EINVAL; |
240 | timeout = new_timeout; |
241 | sc1200wdt_write_data(WDTO, timeout); |
242 | /* fall through and return the new timeout */ |
243 | |
244 | case WDIOC_GETTIMEOUT: |
245 | return put_user(timeout * 60, p); |
246 | |
247 | default: |
248 | return -ENOTTY; |
249 | } |
250 | } |
251 | |
252 | |
253 | static int sc1200wdt_release(struct inode *inode, struct file *file) |
254 | { |
255 | if (expect_close == 42) { |
256 | sc1200wdt_stop(); |
257 | printk(KERN_INFO PFX "Watchdog disabled\n"); |
258 | } else { |
259 | sc1200wdt_write_data(WDTO, timeout); |
260 | printk(KERN_CRIT PFX |
261 | "Unexpected close!, timeout = %d min(s)\n", timeout); |
262 | } |
263 | clear_bit(0, &open_flag); |
264 | expect_close = 0; |
265 | |
266 | return 0; |
267 | } |
268 | |
269 | |
270 | static ssize_t sc1200wdt_write(struct file *file, const char __user *data, |
271 | size_t len, loff_t *ppos) |
272 | { |
273 | if (len) { |
274 | if (!nowayout) { |
275 | size_t i; |
276 | |
277 | expect_close = 0; |
278 | |
279 | for (i = 0; i != len; i++) { |
280 | char c; |
281 | |
282 | if (get_user(c, data + i)) |
283 | return -EFAULT; |
284 | if (c == 'V') |
285 | expect_close = 42; |
286 | } |
287 | } |
288 | |
289 | sc1200wdt_write_data(WDTO, timeout); |
290 | return len; |
291 | } |
292 | |
293 | return 0; |
294 | } |
295 | |
296 | |
297 | static int sc1200wdt_notify_sys(struct notifier_block *this, |
298 | unsigned long code, void *unused) |
299 | { |
300 | if (code == SYS_DOWN || code == SYS_HALT) |
301 | sc1200wdt_stop(); |
302 | |
303 | return NOTIFY_DONE; |
304 | } |
305 | |
306 | |
307 | static struct notifier_block sc1200wdt_notifier = { |
308 | .notifier_call = sc1200wdt_notify_sys, |
309 | }; |
310 | |
311 | static const struct file_operations sc1200wdt_fops = { |
312 | .owner = THIS_MODULE, |
313 | .llseek = no_llseek, |
314 | .write = sc1200wdt_write, |
315 | .unlocked_ioctl = sc1200wdt_ioctl, |
316 | .open = sc1200wdt_open, |
317 | .release = sc1200wdt_release, |
318 | }; |
319 | |
320 | static struct miscdevice sc1200wdt_miscdev = { |
321 | .minor = WATCHDOG_MINOR, |
322 | .name = "watchdog", |
323 | .fops = &sc1200wdt_fops, |
324 | }; |
325 | |
326 | |
327 | static int __init sc1200wdt_probe(void) |
328 | { |
329 | /* The probe works by reading the PMC3 register's default value of 0x0e |
330 | * there is one caveat, if the device disables the parallel port or any |
331 | * of the UARTs we won't be able to detect it. |
332 | * NB. This could be done with accuracy by reading the SID registers, |
333 | * but we don't have access to those io regions. |
334 | */ |
335 | |
336 | unsigned char reg; |
337 | |
338 | sc1200wdt_read_data(PMC3, ®); |
339 | reg &= 0x0f; /* we don't want the UART busy bits */ |
340 | return (reg == 0x0e) ? 0 : -ENODEV; |
341 | } |
342 | |
343 | |
344 | #if defined CONFIG_PNP |
345 | |
346 | static struct pnp_device_id scl200wdt_pnp_devices[] = { |
347 | /* National Semiconductor PC87307/PC97307 watchdog component */ |
348 | {.id = "NSC0800", .driver_data = 0}, |
349 | {.id = ""}, |
350 | }; |
351 | |
352 | static int scl200wdt_pnp_probe(struct pnp_dev *dev, |
353 | const struct pnp_device_id *dev_id) |
354 | { |
355 | /* this driver only supports one card at a time */ |
356 | if (wdt_dev || !isapnp) |
357 | return -EBUSY; |
358 | |
359 | wdt_dev = dev; |
360 | io = pnp_port_start(wdt_dev, 0); |
361 | io_len = pnp_port_len(wdt_dev, 0); |
362 | |
363 | if (!request_region(io, io_len, SC1200_MODULE_NAME)) { |
364 | printk(KERN_ERR PFX "Unable to register IO port %#x\n", io); |
365 | return -EBUSY; |
366 | } |
367 | |
368 | printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n", |
369 | io, io_len); |
370 | return 0; |
371 | } |
372 | |
373 | static void scl200wdt_pnp_remove(struct pnp_dev *dev) |
374 | { |
375 | if (wdt_dev) { |
376 | release_region(io, io_len); |
377 | wdt_dev = NULL; |
378 | } |
379 | } |
380 | |
381 | static struct pnp_driver scl200wdt_pnp_driver = { |
382 | .name = "scl200wdt", |
383 | .id_table = scl200wdt_pnp_devices, |
384 | .probe = scl200wdt_pnp_probe, |
385 | .remove = scl200wdt_pnp_remove, |
386 | }; |
387 | |
388 | #endif /* CONFIG_PNP */ |
389 | |
390 | |
391 | static int __init sc1200wdt_init(void) |
392 | { |
393 | int ret; |
394 | |
395 | printk(KERN_INFO "%s\n", banner); |
396 | |
397 | #if defined CONFIG_PNP |
398 | if (isapnp) { |
399 | ret = pnp_register_driver(&scl200wdt_pnp_driver); |
400 | if (ret) |
401 | goto out_clean; |
402 | } |
403 | #endif |
404 | |
405 | if (io == -1) { |
406 | printk(KERN_ERR PFX "io parameter must be specified\n"); |
407 | ret = -EINVAL; |
408 | goto out_pnp; |
409 | } |
410 | |
411 | #if defined CONFIG_PNP |
412 | /* now that the user has specified an IO port and we haven't detected |
413 | * any devices, disable pnp support */ |
414 | isapnp = 0; |
415 | pnp_unregister_driver(&scl200wdt_pnp_driver); |
416 | #endif |
417 | |
418 | if (!request_region(io, io_len, SC1200_MODULE_NAME)) { |
419 | printk(KERN_ERR PFX "Unable to register IO port %#x\n", io); |
420 | ret = -EBUSY; |
421 | goto out_pnp; |
422 | } |
423 | |
424 | ret = sc1200wdt_probe(); |
425 | if (ret) |
426 | goto out_io; |
427 | |
428 | ret = register_reboot_notifier(&sc1200wdt_notifier); |
429 | if (ret) { |
430 | printk(KERN_ERR PFX |
431 | "Unable to register reboot notifier err = %d\n", ret); |
432 | goto out_io; |
433 | } |
434 | |
435 | ret = misc_register(&sc1200wdt_miscdev); |
436 | if (ret) { |
437 | printk(KERN_ERR PFX |
438 | "Unable to register miscdev on minor %d\n", |
439 | WATCHDOG_MINOR); |
440 | goto out_rbt; |
441 | } |
442 | |
443 | /* ret = 0 */ |
444 | |
445 | out_clean: |
446 | return ret; |
447 | |
448 | out_rbt: |
449 | unregister_reboot_notifier(&sc1200wdt_notifier); |
450 | |
451 | out_io: |
452 | release_region(io, io_len); |
453 | |
454 | out_pnp: |
455 | #if defined CONFIG_PNP |
456 | if (isapnp) |
457 | pnp_unregister_driver(&scl200wdt_pnp_driver); |
458 | #endif |
459 | goto out_clean; |
460 | } |
461 | |
462 | |
463 | static void __exit sc1200wdt_exit(void) |
464 | { |
465 | misc_deregister(&sc1200wdt_miscdev); |
466 | unregister_reboot_notifier(&sc1200wdt_notifier); |
467 | |
468 | #if defined CONFIG_PNP |
469 | if (isapnp) |
470 | pnp_unregister_driver(&scl200wdt_pnp_driver); |
471 | else |
472 | #endif |
473 | release_region(io, io_len); |
474 | } |
475 | |
476 | module_init(sc1200wdt_init); |
477 | module_exit(sc1200wdt_exit); |
478 | |
479 | MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>"); |
480 | MODULE_DESCRIPTION( |
481 | "Driver for National Semiconductor PC87307/PC97307 watchdog component"); |
482 | MODULE_LICENSE("GPL"); |
483 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
484 |
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