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Wim Van Sebroeck4c6e63b2008-10-22 08:59:25 +00001/*
2 * sch311x_wdt.c - Driver for the SCH311x Super-I/O chips
3 * integrated watchdog.
4 *
5 * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
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 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
13 * provide warranty for any of this software. This material is
14 * provided "AS-IS" and at no charge.
15 */
16
17/*
18 * Includes, defines, variables, module parameters, ...
19 */
20
21/* Includes */
22#include <linux/module.h> /* For module specific items */
23#include <linux/moduleparam.h> /* For new moduleparam's */
24#include <linux/types.h> /* For standard types (like size_t) */
25#include <linux/errno.h> /* For the -ENODEV/... values */
26#include <linux/kernel.h> /* For printk/... */
27#include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV
28 (WATCHDOG_MINOR) */
29#include <linux/watchdog.h> /* For the watchdog specific items */
30#include <linux/init.h> /* For __init/__exit/... */
31#include <linux/fs.h> /* For file operations */
32#include <linux/platform_device.h> /* For platform_driver framework */
33#include <linux/ioport.h> /* For io-port access */
34#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
35#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
36#include <linux/io.h> /* For inb/outb/... */
37
38/* Module and version information */
39#define DRV_NAME "sch311x_wdt"
40#define PFX DRV_NAME ": "
41
42/* Runtime registers */
43#define RESGEN 0x1d
44#define GP60 0x47
45#define WDT_TIME_OUT 0x65
46#define WDT_VAL 0x66
47#define WDT_CFG 0x67
48#define WDT_CTRL 0x68
49
50/* internal variables */
51static unsigned long sch311x_wdt_is_open;
52static char sch311x_wdt_expect_close;
53static struct platform_device *sch311x_wdt_pdev;
54
55static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
56
57static struct { /* The devices private data */
58 /* the Runtime Register base address */
59 unsigned short runtime_reg;
60 /* The card's boot status */
61 int boot_status;
62 /* the lock for io operations */
63 spinlock_t io_lock;
64} sch311x_wdt_data;
65
66/* Module load parameters */
67static unsigned short force_id;
68module_param(force_id, ushort, 0);
69MODULE_PARM_DESC(force_id, "Override the detected device ID");
70
71static unsigned short therm_trip;
72module_param(therm_trip, ushort, 0);
73MODULE_PARM_DESC(therm_trip, "Should a ThermTrip trigger the reset generator");
74
75#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
76static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
77module_param(timeout, int, 0);
78MODULE_PARM_DESC(timeout,
79 "Watchdog timeout in seconds. 1<= timeout <=15300, default="
80 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
81
82static int nowayout = WATCHDOG_NOWAYOUT;
83module_param(nowayout, int, 0);
84MODULE_PARM_DESC(nowayout,
85 "Watchdog cannot be stopped once started (default="
86 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
87
88/*
89 * Super-IO functions
90 */
91
92static inline void sch311x_sio_enter(int sio_config_port)
93{
94 outb(0x55, sio_config_port);
95}
96
97static inline void sch311x_sio_exit(int sio_config_port)
98{
99 outb(0xaa, sio_config_port);
100}
101
102static inline int sch311x_sio_inb(int sio_config_port, int reg)
103{
104 outb(reg, sio_config_port);
105 return inb(sio_config_port + 1);
106}
107
108static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
109{
110 outb(reg, sio_config_port);
111 outb(val, sio_config_port + 1);
112}
113
114/*
115 * Watchdog Operations
116 */
117
118static void sch311x_wdt_set_timeout(int t)
119{
120 unsigned char timeout_unit = 0x80;
121
122 /* When new timeout is bigger then 255 seconds, we will use minutes */
123 if (t > 255) {
124 timeout_unit = 0;
125 t /= 60;
126 }
127
128 /* -- Watchdog Timeout --
129 * Bit 0-6 (Reserved)
130 * Bit 7 WDT Time-out Value Units Select
131 * (0 = Minutes, 1 = Seconds)
132 */
133 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
134
135 /* -- Watchdog Timer Time-out Value --
136 * Bit 0-7 Binary coded units (0=Disabled, 1..255)
137 */
138 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
139}
140
141static void sch311x_wdt_start(void)
142{
143 spin_lock(&sch311x_wdt_data.io_lock);
144
145 /* set watchdog's timeout */
146 sch311x_wdt_set_timeout(timeout);
147 /* enable the watchdog */
148 /* -- General Purpose I/O Bit 6.0 --
149 * Bit 0, In/Out: 0 = Output, 1 = Input
150 * Bit 1, Polarity: 0 = No Invert, 1 = Invert
151 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
152 * 10 = Either Edge Triggered Intr.4
153 * Bit 4-6 (Reserved)
154 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
155 */
156 outb(0x0e, sch311x_wdt_data.runtime_reg + GP60);
157
158 spin_unlock(&sch311x_wdt_data.io_lock);
159
160}
161
162static void sch311x_wdt_stop(void)
163{
164 spin_lock(&sch311x_wdt_data.io_lock);
165
166 /* stop the watchdog */
167 outb(0x01, sch311x_wdt_data.runtime_reg + GP60);
168 /* disable timeout by setting it to 0 */
169 sch311x_wdt_set_timeout(0);
170
171 spin_unlock(&sch311x_wdt_data.io_lock);
172}
173
174static void sch311x_wdt_keepalive(void)
175{
176 spin_lock(&sch311x_wdt_data.io_lock);
177 sch311x_wdt_set_timeout(timeout);
178 spin_unlock(&sch311x_wdt_data.io_lock);
179}
180
181static int sch311x_wdt_set_heartbeat(int t)
182{
183 if (t < 1 || t > (255*60))
184 return -EINVAL;
185
186 /* When new timeout is bigger then 255 seconds,
187 * we will round up to minutes (with a max of 255) */
188 if (t > 255)
189 t = (((t - 1) / 60) + 1) * 60;
190
191 timeout = t;
192 return 0;
193}
194
195static void sch311x_wdt_get_status(int *status)
196{
197 unsigned char new_status;
198
199 *status = 0;
200
201 spin_lock(&sch311x_wdt_data.io_lock);
202
203 /* -- Watchdog timer control --
204 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occured
205 * Bit 1 Reserved
206 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
207 * Bit 3 P20 Force Timeout enabled:
208 * 0 = P20 activity does not generate the WD timeout event
209 * 1 = P20 Allows rising edge of P20, from the keyboard
210 * controller, to force the WD timeout event.
211 * Bit 4-7 Reserved
212 */
213 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
214 if (new_status & 0x01)
215 *status |= WDIOF_CARDRESET;
216
217 spin_unlock(&sch311x_wdt_data.io_lock);
218}
219
220/*
221 * /dev/watchdog handling
222 */
223
224static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
225 size_t count, loff_t *ppos)
226{
227 if (count) {
228 if (!nowayout) {
229 size_t i;
230
231 sch311x_wdt_expect_close = 0;
232
233 for (i = 0; i != count; i++) {
234 char c;
235 if (get_user(c, buf + i))
236 return -EFAULT;
237 if (c == 'V')
238 sch311x_wdt_expect_close = 42;
239 }
240 }
241 sch311x_wdt_keepalive();
242 }
243 return count;
244}
245
246static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
247 unsigned long arg)
248{
249 int status;
250 int new_timeout;
251 void __user *argp = (void __user *)arg;
252 int __user *p = argp;
253 static struct watchdog_info ident = {
254 .options = WDIOF_KEEPALIVEPING |
255 WDIOF_SETTIMEOUT |
256 WDIOF_MAGICCLOSE,
257 .firmware_version = 1,
258 .identity = DRV_NAME,
259 };
260
261 switch (cmd) {
262 case WDIOC_GETSUPPORT:
263 if (copy_to_user(argp, &ident, sizeof(ident)))
264 return -EFAULT;
265 break;
266
267 case WDIOC_GETSTATUS:
268 {
269 sch311x_wdt_get_status(&status);
270 return put_user(status, p);
271 }
272 case WDIOC_GETBOOTSTATUS:
273 return put_user(sch311x_wdt_data.boot_status, p);
274
275 case WDIOC_SETOPTIONS:
276 {
277 int options, retval = -EINVAL;
278
279 if (get_user(options, p))
280 return -EFAULT;
281 if (options & WDIOS_DISABLECARD) {
282 sch311x_wdt_stop();
283 retval = 0;
284 }
285 if (options & WDIOS_ENABLECARD) {
286 sch311x_wdt_start();
287 retval = 0;
288 }
289 return retval;
290 }
291 case WDIOC_KEEPALIVE:
292 sch311x_wdt_keepalive();
293 break;
294
295 case WDIOC_SETTIMEOUT:
296 if (get_user(new_timeout, p))
297 return -EFAULT;
298 if (sch311x_wdt_set_heartbeat(new_timeout))
299 return -EINVAL;
300 sch311x_wdt_keepalive();
301 /* Fall */
302 case WDIOC_GETTIMEOUT:
303 return put_user(timeout, p);
304 default:
305 return -ENOTTY;
306 }
307 return 0;
308}
309
310static int sch311x_wdt_open(struct inode *inode, struct file *file)
311{
312 if (test_and_set_bit(0, &sch311x_wdt_is_open))
313 return -EBUSY;
314 /*
315 * Activate
316 */
317 sch311x_wdt_start();
318 return nonseekable_open(inode, file);
319}
320
321static int sch311x_wdt_close(struct inode *inode, struct file *file)
322{
323 if (sch311x_wdt_expect_close == 42) {
324 sch311x_wdt_stop();
325 } else {
326 printk(KERN_CRIT PFX
327 "Unexpected close, not stopping watchdog!\n");
328 sch311x_wdt_keepalive();
329 }
330 clear_bit(0, &sch311x_wdt_is_open);
331 sch311x_wdt_expect_close = 0;
332 return 0;
333}
334
335/*
336 * Kernel Interfaces
337 */
338
339static const struct file_operations sch311x_wdt_fops = {
340 .owner = THIS_MODULE,
341 .llseek = no_llseek,
342 .write = sch311x_wdt_write,
343 .unlocked_ioctl = sch311x_wdt_ioctl,
344 .open = sch311x_wdt_open,
345 .release = sch311x_wdt_close,
346};
347
348static struct miscdevice sch311x_wdt_miscdev = {
349 .minor = WATCHDOG_MINOR,
350 .name = "watchdog",
351 .fops = &sch311x_wdt_fops,
352};
353
354/*
355 * Init & exit routines
356 */
357
358static int __devinit sch311x_wdt_probe(struct platform_device *pdev)
359{
360 struct device *dev = &pdev->dev;
361 unsigned char val;
362 int err;
363
364 spin_lock_init(&sch311x_wdt_data.io_lock);
365
366 if (!request_region(sch311x_wdt_data.runtime_reg + RESGEN, 1,
367 DRV_NAME)) {
368 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
369 sch311x_wdt_data.runtime_reg + RESGEN,
370 sch311x_wdt_data.runtime_reg + RESGEN);
371 err = -EBUSY;
372 goto exit;
373 }
374
375 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
376 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
377 sch311x_wdt_data.runtime_reg + GP60,
378 sch311x_wdt_data.runtime_reg + GP60);
379 err = -EBUSY;
380 goto exit_release_region;
381 }
382
383 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
384 DRV_NAME)) {
385 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
386 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
387 sch311x_wdt_data.runtime_reg + WDT_CTRL);
388 err = -EBUSY;
389 goto exit_release_region2;
390 }
391
392 /* Make sure that the watchdog is not running */
393 sch311x_wdt_stop();
394
395 /* Disable keyboard and mouse interaction and interrupt */
396 /* -- Watchdog timer configuration --
397 * Bit 0 Reserved
398 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
399 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
400 * Bit 3 Reserved
401 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
402 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
403 */
404 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
405
406 /* Check that the heartbeat value is within it's range ;
407 * if not reset to the default */
408 if (sch311x_wdt_set_heartbeat(timeout)) {
409 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
410 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
411 timeout);
412 }
413
414 /* Get status at boot */
415 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
416
417 /* enable watchdog */
418 /* -- Reset Generator --
419 * Bit 0 Enable Watchdog Timer Generation: 0* = Enabled, 1 = Disabled
420 * Bit 1 Thermtrip Source Select: O* = No Source, 1 = Source
421 * Bit 2 WDT2_CTL: WDT input bit
422 * Bit 3-7 Reserved
423 */
424 outb(0, sch311x_wdt_data.runtime_reg + RESGEN);
425 val = therm_trip ? 0x06 : 0x04;
426 outb(val, sch311x_wdt_data.runtime_reg + RESGEN);
427
428 err = misc_register(&sch311x_wdt_miscdev);
429 if (err != 0) {
430 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
431 WATCHDOG_MINOR, err);
432 goto exit_release_region3;
433 }
434
435 sch311x_wdt_miscdev.parent = dev;
436
437 dev_info(dev,
438 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
439 timeout, nowayout);
440
441 return 0;
442
443exit_release_region3:
444 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
445exit_release_region2:
446 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
447exit_release_region:
448 release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
449 sch311x_wdt_data.runtime_reg = 0;
450exit:
451 return err;
452}
453
454static int __devexit sch311x_wdt_remove(struct platform_device *pdev)
455{
456 /* Stop the timer before we leave */
457 if (!nowayout)
458 sch311x_wdt_stop();
459
460 /* Deregister */
461 misc_deregister(&sch311x_wdt_miscdev);
462 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
463 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
464 release_region(sch311x_wdt_data.runtime_reg + RESGEN, 1);
465 sch311x_wdt_data.runtime_reg = 0;
466 return 0;
467}
468
469static void sch311x_wdt_shutdown(struct platform_device *dev)
470{
471 /* Turn the WDT off if we have a soft shutdown */
472 sch311x_wdt_stop();
473}
474
475#define sch311x_wdt_suspend NULL
476#define sch311x_wdt_resume NULL
477
478static struct platform_driver sch311x_wdt_driver = {
479 .probe = sch311x_wdt_probe,
480 .remove = __devexit_p(sch311x_wdt_remove),
481 .shutdown = sch311x_wdt_shutdown,
482 .suspend = sch311x_wdt_suspend,
483 .resume = sch311x_wdt_resume,
484 .driver = {
485 .owner = THIS_MODULE,
486 .name = DRV_NAME,
487 },
488};
489
490static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
491{
492 int err = 0, reg;
493 unsigned short base_addr;
494 unsigned char dev_id;
495
496 sch311x_sio_enter(sio_config_port);
497
498 /* Check device ID. We currently know about:
499 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
500 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
501 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
502 err = -ENODEV;
503 goto exit;
504 }
505 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
506
507 /* Select logical device A (runtime registers) */
508 sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
509
510 /* Check if Logical Device Register is currently active */
511 if (sch311x_sio_inb(sio_config_port, 0x30) && 0x01 == 0)
512 printk(KERN_INFO PFX "Seems that LDN 0x0a is not active...\n");
513
514 /* Get the base address of the runtime registers */
515 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
516 sch311x_sio_inb(sio_config_port, 0x61);
517 if (!base_addr) {
518 printk(KERN_ERR PFX "Base address not set.\n");
519 err = -ENODEV;
520 goto exit;
521 }
522 *addr = base_addr;
523
524 printk(KERN_INFO PFX "Found an SMSC SCH311%d chip at 0x%04x\n",
525 dev_id, base_addr);
526
527exit:
528 sch311x_sio_exit(sio_config_port);
529 return err;
530}
531
532static int __init sch311x_wdt_init(void)
533{
534 int err, i, found = 0;
535 unsigned short addr = 0;
536
537 for (i = 0; !found && sch311x_ioports[i]; i++)
538 if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
539 found++;
540
541 if (!found)
542 return -ENODEV;
543
544 sch311x_wdt_data.runtime_reg = addr;
545
546 err = platform_driver_register(&sch311x_wdt_driver);
547 if (err)
548 return err;
549
550 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
551 NULL, 0);
552
553 if (IS_ERR(sch311x_wdt_pdev)) {
554 err = PTR_ERR(sch311x_wdt_pdev);
555 goto unreg_platform_driver;
556 }
557
558 return 0;
559
560unreg_platform_driver:
561 platform_driver_unregister(&sch311x_wdt_driver);
562 return err;
563}
564
565static void __exit sch311x_wdt_exit(void)
566{
567 platform_device_unregister(sch311x_wdt_pdev);
568 platform_driver_unregister(&sch311x_wdt_driver);
569}
570
571module_init(sch311x_wdt_init);
572module_exit(sch311x_wdt_exit);
573
574MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
575MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
576MODULE_LICENSE("GPL");
577MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
578