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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
4 * (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
5 * All Rights Reserved.
6 * Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
7 *
8 * The author(s) of this software shall not be held liable for damages
9 * of any nature resulting due to the use of this software. This
10 * software is provided AS-IS with no warranties.
11 *
12 * Changelog:
13 * 20020220 Zwane Mwaikambo Code based on datasheet, no hardware.
14 * 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik
15 * and Alan Cox.
16 * 20020222 Zwane Mwaikambo Added probing.
17 * 20020225 Zwane Mwaikambo Added ISAPNP support.
18 * 20020412 Rob Radez Broke out start/stop functions
19 * <rob@osinvestor.com> Return proper status instead of
20 * temperature warning
21 * Add WDIOC_GETBOOTSTATUS and
22 * WDIOC_SETOPTIONS ioctls
23 * Fix CONFIG_WATCHDOG_NOWAYOUT
24 * 20020530 Joel Becker Add Matt Domsch's nowayout module
25 * option
26 * 20030116 Adam Belay Updated to the latest pnp code
27 */
28
29#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
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/semaphore.h>
43#include <linux/io.h>
44#include <linux/uaccess.h>
45
46#define SC1200_MODULE_VER "build 20020303"
47#define SC1200_MODULE_NAME "sc1200wdt"
48
49#define MAX_TIMEOUT 255 /* 255 minutes */
50#define PMIR (io) /* Power Management Index Register */
51#define PMDR (io+1) /* Power Management Data Register */
52
53/* Data Register indexes */
54#define FER1 0x00 /* Function enable register 1 */
55#define FER2 0x01 /* Function enable register 2 */
56#define PMC1 0x02 /* Power Management Ctrl 1 */
57#define PMC2 0x03 /* Power Management Ctrl 2 */
58#define PMC3 0x04 /* Power Management Ctrl 3 */
59#define WDTO 0x05 /* Watchdog timeout register */
60#define WDCF 0x06 /* Watchdog config register */
61#define WDST 0x07 /* Watchdog status register */
62
63/* WDCF bitfields - which devices assert WDO */
64#define KBC_IRQ 0x01 /* Keyboard Controller */
65#define MSE_IRQ 0x02 /* Mouse */
66#define UART1_IRQ 0x03 /* Serial0 */
67#define UART2_IRQ 0x04 /* Serial1 */
68/* 5 -7 are reserved */
69
70static int timeout = 1;
71static int io = -1;
72static int io_len = 2; /* for non plug and play */
73static unsigned long open_flag;
74static char expect_close;
75static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */
76
77#if defined CONFIG_PNP
78static int isapnp = 1;
79static struct pnp_dev *wdt_dev;
80
81module_param(isapnp, int, 0);
82MODULE_PARM_DESC(isapnp,
83 "When set to 0 driver ISA PnP support will be disabled");
84#endif
85
86module_param_hw(io, int, ioport, 0);
87MODULE_PARM_DESC(io, "io port");
88module_param(timeout, int, 0);
89MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
90
91static bool nowayout = WATCHDOG_NOWAYOUT;
92module_param(nowayout, bool, 0);
93MODULE_PARM_DESC(nowayout,
94 "Watchdog cannot be stopped once started (default="
95 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
96
97
98
99/* Read from Data Register */
100static inline void __sc1200wdt_read_data(unsigned char index,
101 unsigned char *data)
102{
103 outb_p(index, PMIR);
104 *data = inb(PMDR);
105}
106
107static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
108{
109 spin_lock(&sc1200wdt_lock);
110 __sc1200wdt_read_data(index, data);
111 spin_unlock(&sc1200wdt_lock);
112}
113
114/* Write to Data Register */
115static inline void __sc1200wdt_write_data(unsigned char index,
116 unsigned char data)
117{
118 outb_p(index, PMIR);
119 outb(data, PMDR);
120}
121
122static inline void sc1200wdt_write_data(unsigned char index,
123 unsigned char data)
124{
125 spin_lock(&sc1200wdt_lock);
126 __sc1200wdt_write_data(index, data);
127 spin_unlock(&sc1200wdt_lock);
128}
129
130
131static void sc1200wdt_start(void)
132{
133 unsigned char reg;
134 spin_lock(&sc1200wdt_lock);
135
136 __sc1200wdt_read_data(WDCF, ®);
137 /* assert WDO when any of the following interrupts are triggered too */
138 reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
139 __sc1200wdt_write_data(WDCF, reg);
140 /* set the timeout and get the ball rolling */
141 __sc1200wdt_write_data(WDTO, timeout);
142
143 spin_unlock(&sc1200wdt_lock);
144}
145
146static void sc1200wdt_stop(void)
147{
148 sc1200wdt_write_data(WDTO, 0);
149}
150
151/* This returns the status of the WDO signal, inactive high. */
152static inline int sc1200wdt_status(void)
153{
154 unsigned char ret;
155
156 sc1200wdt_read_data(WDST, &ret);
157 /* If the bit is inactive, the watchdog is enabled, so return
158 * KEEPALIVEPING which is a bit of a kludge because there's nothing
159 * else for enabled/disabled status
160 */
161 return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
162}
163
164static int sc1200wdt_open(struct inode *inode, struct file *file)
165{
166 /* allow one at a time */
167 if (test_and_set_bit(0, &open_flag))
168 return -EBUSY;
169
170 if (timeout > MAX_TIMEOUT)
171 timeout = MAX_TIMEOUT;
172
173 sc1200wdt_start();
174 pr_info("Watchdog enabled, timeout = %d min(s)", timeout);
175
176 return stream_open(inode, file);
177}
178
179
180static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
181 unsigned long arg)
182{
183 int new_timeout;
184 void __user *argp = (void __user *)arg;
185 int __user *p = argp;
186 static const struct watchdog_info ident = {
187 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
188 WDIOF_MAGICCLOSE,
189 .firmware_version = 0,
190 .identity = "PC87307/PC97307",
191 };
192
193 switch (cmd) {
194 case WDIOC_GETSUPPORT:
195 if (copy_to_user(argp, &ident, sizeof(ident)))
196 return -EFAULT;
197 return 0;
198
199 case WDIOC_GETSTATUS:
200 return put_user(sc1200wdt_status(), p);
201
202 case WDIOC_GETBOOTSTATUS:
203 return put_user(0, p);
204
205 case WDIOC_SETOPTIONS:
206 {
207 int options, retval = -EINVAL;
208
209 if (get_user(options, p))
210 return -EFAULT;
211
212 if (options & WDIOS_DISABLECARD) {
213 sc1200wdt_stop();
214 retval = 0;
215 }
216
217 if (options & WDIOS_ENABLECARD) {
218 sc1200wdt_start();
219 retval = 0;
220 }
221
222 return retval;
223 }
224 case WDIOC_KEEPALIVE:
225 sc1200wdt_write_data(WDTO, timeout);
226 return 0;
227
228 case WDIOC_SETTIMEOUT:
229 if (get_user(new_timeout, p))
230 return -EFAULT;
231 /* the API states this is given in secs */
232 new_timeout /= 60;
233 if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
234 return -EINVAL;
235 timeout = new_timeout;
236 sc1200wdt_write_data(WDTO, timeout);
237 fallthrough; /* and return the new timeout */
238
239 case WDIOC_GETTIMEOUT:
240 return put_user(timeout * 60, p);
241
242 default:
243 return -ENOTTY;
244 }
245}
246
247
248static int sc1200wdt_release(struct inode *inode, struct file *file)
249{
250 if (expect_close == 42) {
251 sc1200wdt_stop();
252 pr_info("Watchdog disabled\n");
253 } else {
254 sc1200wdt_write_data(WDTO, timeout);
255 pr_crit("Unexpected close!, timeout = %d min(s)\n", timeout);
256 }
257 clear_bit(0, &open_flag);
258 expect_close = 0;
259
260 return 0;
261}
262
263
264static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
265 size_t len, loff_t *ppos)
266{
267 if (len) {
268 if (!nowayout) {
269 size_t i;
270
271 expect_close = 0;
272
273 for (i = 0; i != len; i++) {
274 char c;
275
276 if (get_user(c, data + i))
277 return -EFAULT;
278 if (c == 'V')
279 expect_close = 42;
280 }
281 }
282
283 sc1200wdt_write_data(WDTO, timeout);
284 return len;
285 }
286
287 return 0;
288}
289
290
291static int sc1200wdt_notify_sys(struct notifier_block *this,
292 unsigned long code, void *unused)
293{
294 if (code == SYS_DOWN || code == SYS_HALT)
295 sc1200wdt_stop();
296
297 return NOTIFY_DONE;
298}
299
300
301static struct notifier_block sc1200wdt_notifier = {
302 .notifier_call = sc1200wdt_notify_sys,
303};
304
305static const struct file_operations sc1200wdt_fops = {
306 .owner = THIS_MODULE,
307 .llseek = no_llseek,
308 .write = sc1200wdt_write,
309 .unlocked_ioctl = sc1200wdt_ioctl,
310 .compat_ioctl = compat_ptr_ioctl,
311 .open = sc1200wdt_open,
312 .release = sc1200wdt_release,
313};
314
315static struct miscdevice sc1200wdt_miscdev = {
316 .minor = WATCHDOG_MINOR,
317 .name = "watchdog",
318 .fops = &sc1200wdt_fops,
319};
320
321
322static int __init sc1200wdt_probe(void)
323{
324 /* The probe works by reading the PMC3 register's default value of 0x0e
325 * there is one caveat, if the device disables the parallel port or any
326 * of the UARTs we won't be able to detect it.
327 * NB. This could be done with accuracy by reading the SID registers,
328 * but we don't have access to those io regions.
329 */
330
331 unsigned char reg;
332
333 sc1200wdt_read_data(PMC3, ®);
334 reg &= 0x0f; /* we don't want the UART busy bits */
335 return (reg == 0x0e) ? 0 : -ENODEV;
336}
337
338
339#if defined CONFIG_PNP
340
341static const struct pnp_device_id scl200wdt_pnp_devices[] = {
342 /* National Semiconductor PC87307/PC97307 watchdog component */
343 {.id = "NSC0800", .driver_data = 0},
344 {.id = ""},
345};
346
347static int scl200wdt_pnp_probe(struct pnp_dev *dev,
348 const struct pnp_device_id *dev_id)
349{
350 /* this driver only supports one card at a time */
351 if (wdt_dev || !isapnp)
352 return -EBUSY;
353
354 wdt_dev = dev;
355 io = pnp_port_start(wdt_dev, 0);
356 io_len = pnp_port_len(wdt_dev, 0);
357
358 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
359 pr_err("Unable to register IO port %#x\n", io);
360 return -EBUSY;
361 }
362
363 pr_info("PnP device found at io port %#x/%d\n", io, io_len);
364 return 0;
365}
366
367static void scl200wdt_pnp_remove(struct pnp_dev *dev)
368{
369 if (wdt_dev) {
370 release_region(io, io_len);
371 wdt_dev = NULL;
372 }
373}
374
375static struct pnp_driver scl200wdt_pnp_driver = {
376 .name = "scl200wdt",
377 .id_table = scl200wdt_pnp_devices,
378 .probe = scl200wdt_pnp_probe,
379 .remove = scl200wdt_pnp_remove,
380};
381
382#endif /* CONFIG_PNP */
383
384
385static int __init sc1200wdt_init(void)
386{
387 int ret;
388
389 pr_info("%s\n", SC1200_MODULE_VER);
390
391#if defined CONFIG_PNP
392 if (isapnp) {
393 ret = pnp_register_driver(&scl200wdt_pnp_driver);
394 if (ret)
395 goto out_clean;
396 }
397#endif
398
399 if (io == -1) {
400 pr_err("io parameter must be specified\n");
401 ret = -EINVAL;
402 goto out_pnp;
403 }
404
405#if defined CONFIG_PNP
406 /* now that the user has specified an IO port and we haven't detected
407 * any devices, disable pnp support */
408 if (isapnp)
409 pnp_unregister_driver(&scl200wdt_pnp_driver);
410 isapnp = 0;
411#endif
412
413 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
414 pr_err("Unable to register IO port %#x\n", io);
415 ret = -EBUSY;
416 goto out_pnp;
417 }
418
419 ret = sc1200wdt_probe();
420 if (ret)
421 goto out_io;
422
423 ret = register_reboot_notifier(&sc1200wdt_notifier);
424 if (ret) {
425 pr_err("Unable to register reboot notifier err = %d\n", ret);
426 goto out_io;
427 }
428
429 ret = misc_register(&sc1200wdt_miscdev);
430 if (ret) {
431 pr_err("Unable to register miscdev on minor %d\n",
432 WATCHDOG_MINOR);
433 goto out_rbt;
434 }
435
436 /* ret = 0 */
437
438out_clean:
439 return ret;
440
441out_rbt:
442 unregister_reboot_notifier(&sc1200wdt_notifier);
443
444out_io:
445 release_region(io, io_len);
446
447out_pnp:
448#if defined CONFIG_PNP
449 if (isapnp)
450 pnp_unregister_driver(&scl200wdt_pnp_driver);
451#endif
452 goto out_clean;
453}
454
455
456static void __exit sc1200wdt_exit(void)
457{
458 misc_deregister(&sc1200wdt_miscdev);
459 unregister_reboot_notifier(&sc1200wdt_notifier);
460
461#if defined CONFIG_PNP
462 if (isapnp)
463 pnp_unregister_driver(&scl200wdt_pnp_driver);
464 else
465#endif
466 release_region(io, io_len);
467}
468
469module_init(sc1200wdt_init);
470module_exit(sc1200wdt_exit);
471
472MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
473MODULE_DESCRIPTION(
474 "Driver for National Semiconductor PC87307/PC97307 watchdog component");
475MODULE_LICENSE("GPL");
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35
36#include <linux/module.h>
37#include <linux/moduleparam.h>
38#include <linux/miscdevice.h>
39#include <linux/watchdog.h>
40#include <linux/ioport.h>
41#include <linux/spinlock.h>
42#include <linux/notifier.h>
43#include <linux/reboot.h>
44#include <linux/init.h>
45#include <linux/pnp.h>
46#include <linux/fs.h>
47#include <linux/semaphore.h>
48#include <linux/io.h>
49#include <linux/uaccess.h>
50
51#define SC1200_MODULE_VER "build 20020303"
52#define SC1200_MODULE_NAME "sc1200wdt"
53
54#define MAX_TIMEOUT 255 /* 255 minutes */
55#define PMIR (io) /* Power Management Index Register */
56#define PMDR (io+1) /* Power Management Data Register */
57
58/* Data Register indexes */
59#define FER1 0x00 /* Function enable register 1 */
60#define FER2 0x01 /* Function enable register 2 */
61#define PMC1 0x02 /* Power Management Ctrl 1 */
62#define PMC2 0x03 /* Power Management Ctrl 2 */
63#define PMC3 0x04 /* Power Management Ctrl 3 */
64#define WDTO 0x05 /* Watchdog timeout register */
65#define WDCF 0x06 /* Watchdog config register */
66#define WDST 0x07 /* Watchdog status register */
67
68/* WDCF bitfields - which devices assert WDO */
69#define KBC_IRQ 0x01 /* Keyboard Controller */
70#define MSE_IRQ 0x02 /* Mouse */
71#define UART1_IRQ 0x03 /* Serial0 */
72#define UART2_IRQ 0x04 /* Serial1 */
73/* 5 -7 are reserved */
74
75static int timeout = 1;
76static int io = -1;
77static int io_len = 2; /* for non plug and play */
78static unsigned long open_flag;
79static char expect_close;
80static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */
81
82#if defined CONFIG_PNP
83static int isapnp = 1;
84static struct pnp_dev *wdt_dev;
85
86module_param(isapnp, int, 0);
87MODULE_PARM_DESC(isapnp,
88 "When set to 0 driver ISA PnP support will be disabled");
89#endif
90
91module_param(io, int, 0);
92MODULE_PARM_DESC(io, "io port");
93module_param(timeout, int, 0);
94MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
95
96static bool nowayout = WATCHDOG_NOWAYOUT;
97module_param(nowayout, bool, 0);
98MODULE_PARM_DESC(nowayout,
99 "Watchdog cannot be stopped once started (default="
100 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
101
102
103
104/* Read from Data Register */
105static inline void __sc1200wdt_read_data(unsigned char index,
106 unsigned char *data)
107{
108 outb_p(index, PMIR);
109 *data = inb(PMDR);
110}
111
112static 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 */
120static inline void __sc1200wdt_write_data(unsigned char index,
121 unsigned char data)
122{
123 outb_p(index, PMIR);
124 outb(data, PMDR);
125}
126
127static 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
136static 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
151static void sc1200wdt_stop(void)
152{
153 sc1200wdt_write_data(WDTO, 0);
154}
155
156/* This returns the status of the WDO signal, inactive high. */
157static 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
169static 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 pr_info("Watchdog enabled, timeout = %d min(s)", timeout);
180
181 return nonseekable_open(inode, file);
182}
183
184
185static 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
253static int sc1200wdt_release(struct inode *inode, struct file *file)
254{
255 if (expect_close == 42) {
256 sc1200wdt_stop();
257 pr_info("Watchdog disabled\n");
258 } else {
259 sc1200wdt_write_data(WDTO, timeout);
260 pr_crit("Unexpected close!, timeout = %d min(s)\n", timeout);
261 }
262 clear_bit(0, &open_flag);
263 expect_close = 0;
264
265 return 0;
266}
267
268
269static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
270 size_t len, loff_t *ppos)
271{
272 if (len) {
273 if (!nowayout) {
274 size_t i;
275
276 expect_close = 0;
277
278 for (i = 0; i != len; i++) {
279 char c;
280
281 if (get_user(c, data + i))
282 return -EFAULT;
283 if (c == 'V')
284 expect_close = 42;
285 }
286 }
287
288 sc1200wdt_write_data(WDTO, timeout);
289 return len;
290 }
291
292 return 0;
293}
294
295
296static int sc1200wdt_notify_sys(struct notifier_block *this,
297 unsigned long code, void *unused)
298{
299 if (code == SYS_DOWN || code == SYS_HALT)
300 sc1200wdt_stop();
301
302 return NOTIFY_DONE;
303}
304
305
306static struct notifier_block sc1200wdt_notifier = {
307 .notifier_call = sc1200wdt_notify_sys,
308};
309
310static const struct file_operations sc1200wdt_fops = {
311 .owner = THIS_MODULE,
312 .llseek = no_llseek,
313 .write = sc1200wdt_write,
314 .unlocked_ioctl = sc1200wdt_ioctl,
315 .open = sc1200wdt_open,
316 .release = sc1200wdt_release,
317};
318
319static struct miscdevice sc1200wdt_miscdev = {
320 .minor = WATCHDOG_MINOR,
321 .name = "watchdog",
322 .fops = &sc1200wdt_fops,
323};
324
325
326static int __init sc1200wdt_probe(void)
327{
328 /* The probe works by reading the PMC3 register's default value of 0x0e
329 * there is one caveat, if the device disables the parallel port or any
330 * of the UARTs we won't be able to detect it.
331 * NB. This could be done with accuracy by reading the SID registers,
332 * but we don't have access to those io regions.
333 */
334
335 unsigned char reg;
336
337 sc1200wdt_read_data(PMC3, ®);
338 reg &= 0x0f; /* we don't want the UART busy bits */
339 return (reg == 0x0e) ? 0 : -ENODEV;
340}
341
342
343#if defined CONFIG_PNP
344
345static struct pnp_device_id scl200wdt_pnp_devices[] = {
346 /* National Semiconductor PC87307/PC97307 watchdog component */
347 {.id = "NSC0800", .driver_data = 0},
348 {.id = ""},
349};
350
351static int scl200wdt_pnp_probe(struct pnp_dev *dev,
352 const struct pnp_device_id *dev_id)
353{
354 /* this driver only supports one card at a time */
355 if (wdt_dev || !isapnp)
356 return -EBUSY;
357
358 wdt_dev = dev;
359 io = pnp_port_start(wdt_dev, 0);
360 io_len = pnp_port_len(wdt_dev, 0);
361
362 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
363 pr_err("Unable to register IO port %#x\n", io);
364 return -EBUSY;
365 }
366
367 pr_info("PnP device found at io port %#x/%d\n", io, io_len);
368 return 0;
369}
370
371static void scl200wdt_pnp_remove(struct pnp_dev *dev)
372{
373 if (wdt_dev) {
374 release_region(io, io_len);
375 wdt_dev = NULL;
376 }
377}
378
379static struct pnp_driver scl200wdt_pnp_driver = {
380 .name = "scl200wdt",
381 .id_table = scl200wdt_pnp_devices,
382 .probe = scl200wdt_pnp_probe,
383 .remove = scl200wdt_pnp_remove,
384};
385
386#endif /* CONFIG_PNP */
387
388
389static int __init sc1200wdt_init(void)
390{
391 int ret;
392
393 pr_info("%s\n", SC1200_MODULE_VER);
394
395#if defined CONFIG_PNP
396 if (isapnp) {
397 ret = pnp_register_driver(&scl200wdt_pnp_driver);
398 if (ret)
399 goto out_clean;
400 }
401#endif
402
403 if (io == -1) {
404 pr_err("io parameter must be specified\n");
405 ret = -EINVAL;
406 goto out_pnp;
407 }
408
409#if defined CONFIG_PNP
410 /* now that the user has specified an IO port and we haven't detected
411 * any devices, disable pnp support */
412 isapnp = 0;
413 pnp_unregister_driver(&scl200wdt_pnp_driver);
414#endif
415
416 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
417 pr_err("Unable to register IO port %#x\n", io);
418 ret = -EBUSY;
419 goto out_pnp;
420 }
421
422 ret = sc1200wdt_probe();
423 if (ret)
424 goto out_io;
425
426 ret = register_reboot_notifier(&sc1200wdt_notifier);
427 if (ret) {
428 pr_err("Unable to register reboot notifier err = %d\n", ret);
429 goto out_io;
430 }
431
432 ret = misc_register(&sc1200wdt_miscdev);
433 if (ret) {
434 pr_err("Unable to register miscdev on minor %d\n",
435 WATCHDOG_MINOR);
436 goto out_rbt;
437 }
438
439 /* ret = 0 */
440
441out_clean:
442 return ret;
443
444out_rbt:
445 unregister_reboot_notifier(&sc1200wdt_notifier);
446
447out_io:
448 release_region(io, io_len);
449
450out_pnp:
451#if defined CONFIG_PNP
452 if (isapnp)
453 pnp_unregister_driver(&scl200wdt_pnp_driver);
454#endif
455 goto out_clean;
456}
457
458
459static void __exit sc1200wdt_exit(void)
460{
461 misc_deregister(&sc1200wdt_miscdev);
462 unregister_reboot_notifier(&sc1200wdt_notifier);
463
464#if defined CONFIG_PNP
465 if (isapnp)
466 pnp_unregister_driver(&scl200wdt_pnp_driver);
467 else
468#endif
469 release_region(io, io_len);
470}
471
472module_init(sc1200wdt_init);
473module_exit(sc1200wdt_exit);
474
475MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
476MODULE_DESCRIPTION(
477 "Driver for National Semiconductor PC87307/PC97307 watchdog component");
478MODULE_LICENSE("GPL");
479MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);