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