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-rw-r--r--drivers/watchdog/sc1200wdt.c463
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diff --git a/drivers/watchdog/sc1200wdt.c b/drivers/watchdog/sc1200wdt.c
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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 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/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>
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
71static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER;
72static int timeout = 1;
73static int io = -1;
74static int io_len = 2; /* for non plug and play */
75static struct semaphore open_sem;
76static char expect_close;
77static spinlock_t sc1200wdt_lock; /* io port access serialisation */
78
79#if defined CONFIG_PNP
80static int isapnp = 1;
81static struct pnp_dev *wdt_dev;
82
83module_param(isapnp, int, 0);
84MODULE_PARM_DESC(isapnp, "When set to 0 driver ISA PnP support will be disabled");
85#endif
86
87module_param(io, int, 0);
88MODULE_PARM_DESC(io, "io port");
89module_param(timeout, int, 0);
90MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
91
92static int nowayout = WATCHDOG_NOWAYOUT;
93module_param(nowayout, int, 0);
94MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
95
96
97
98/* Read from Data Register */
99static 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 */
109static 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
118static void sc1200wdt_start(void)
119{
120 unsigned char reg;
121
122 sc1200wdt_read_data(WDCF, &reg);
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
131static 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. */
138static 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
151static int sc1200wdt_open(struct inode *inode, struct file *file)
152{
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
163 return nonseekable_open(inode, file);
164}
165
166
167static 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:
180 return -ENOTTY;
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
236static 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
252static 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
278static 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
287static struct notifier_block sc1200wdt_notifier =
288{
289 .notifier_call = sc1200wdt_notify_sys,
290};
291
292static const struct file_operations sc1200wdt_fops =
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
302static struct miscdevice sc1200wdt_miscdev =
303{
304 .minor = WATCHDOG_MINOR,
305 .name = "watchdog",
306 .fops = &sc1200wdt_fops,
307};
308
309
310static 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, &reg);
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
329static struct pnp_device_id scl200wdt_pnp_devices[] = {
330 /* National Semiconductor PC87307/PC97307 watchdog component */
331 {.id = "NSC0800", .driver_data = 0},
332 {.id = ""},
333};
334
335static 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
354static 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
362static 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
372static int __init sc1200wdt_init(void)
373{
374 int ret;
375
376 printk("%s\n", banner);
377
378 spin_lock_init(&sc1200wdt_lock);
379 sema_init(&open_sem, 1);
380
381#if defined CONFIG_PNP
382 if (isapnp) {
383 ret = pnp_register_driver(&scl200wdt_pnp_driver);
384 if (ret)
385 goto out_clean;
386 }
387#endif
388
389 if (io == -1) {
390 printk(KERN_ERR PFX "io parameter must be specified\n");
391 ret = -EINVAL;
392 goto out_pnp;
393 }
394
395#if defined CONFIG_PNP
396 /* now that the user has specified an IO port and we haven't detected
397 * any devices, disable pnp support */
398 isapnp = 0;
399 pnp_unregister_driver(&scl200wdt_pnp_driver);
400#endif
401
402 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
403 printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
404 ret = -EBUSY;
405 goto out_pnp;
406 }
407
408 ret = sc1200wdt_probe();
409 if (ret)
410 goto out_io;
411
412 ret = register_reboot_notifier(&sc1200wdt_notifier);
413 if (ret) {
414 printk(KERN_ERR PFX "Unable to register reboot notifier err = %d\n", ret);
415 goto out_io;
416 }
417
418 ret = misc_register(&sc1200wdt_miscdev);
419 if (ret) {
420 printk(KERN_ERR PFX "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR);
421 goto out_rbt;
422 }
423
424 /* ret = 0 */
425
426out_clean:
427 return ret;
428
429out_rbt:
430 unregister_reboot_notifier(&sc1200wdt_notifier);
431
432out_io:
433 release_region(io, io_len);
434
435out_pnp:
436#if defined CONFIG_PNP
437 if (isapnp)
438 pnp_unregister_driver(&scl200wdt_pnp_driver);
439#endif
440 goto out_clean;
441}
442
443
444static void __exit sc1200wdt_exit(void)
445{
446 misc_deregister(&sc1200wdt_miscdev);
447 unregister_reboot_notifier(&sc1200wdt_notifier);
448
449#if defined CONFIG_PNP
450 if(isapnp)
451 pnp_unregister_driver(&scl200wdt_pnp_driver);
452 else
453#endif
454 release_region(io, io_len);
455}
456
457module_init(sc1200wdt_init);
458module_exit(sc1200wdt_exit);
459
460MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
461MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
462MODULE_LICENSE("GPL");
463MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);