aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/watchdog/pcwd_usb.c
blob: 092e9b133750f67f56d803df1ce06039ab6c78cf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
/*
 *	Berkshire USB-PC Watchdog Card Driver
 *
 *	(c) Copyright 2004 Wim Van Sebroeck <wim@iguana.be>.
 *
 *	Based on source code of the following authors:
 *	  Ken Hollis <kenji@bitgate.com>,
 *	  Alan Cox <alan@redhat.com>,
 *	  Matt Domsch <Matt_Domsch@dell.com>,
 *	  Rob Radez <rob@osinvestor.com>,
 *	  Greg Kroah-Hartman <greg@kroah.com>
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
 *	provide warranty for any of this software. This material is
 *	provided "AS-IS" and at no charge.
 *
 *	Thanks also to Simon Machell at Berkshire Products Inc. for
 *	providing the test hardware. More info is available at
 *	http://www.berkprod.com/ or http://www.pcwatchdog.com/
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/smp_lock.h>
#include <linux/completion.h>
#include <asm/uaccess.h>
#include <linux/usb.h>


#ifdef CONFIG_USB_DEBUG
	static int debug = 1;
#else
	static int debug;
#endif

/* Use our own dbg macro */
#undef dbg
#define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)


/* Module and Version Information */
#define DRIVER_VERSION "1.01"
#define DRIVER_DATE "15 Mar 2005"
#define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
#define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
#define DRIVER_LICENSE "GPL"
#define DRIVER_NAME "pcwd_usb"
#define PFX DRIVER_NAME ": "

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE(DRIVER_LICENSE);
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS_MISCDEV(TEMP_MINOR);

/* Module Parameters */
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug enabled or not");

#define WATCHDOG_HEARTBEAT 2	/* 2 sec default heartbeat */
static int heartbeat = WATCHDOG_HEARTBEAT;
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

/* The vendor and product id's for the USB-PC Watchdog card */
#define USB_PCWD_VENDOR_ID	0x0c98
#define USB_PCWD_PRODUCT_ID	0x1140

/* table of devices that work with this driver */
static struct usb_device_id usb_pcwd_table [] = {
	{ USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
	{ }					/* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, usb_pcwd_table);

/* according to documentation max. time to process a command for the USB
 * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
#define USB_COMMAND_TIMEOUT	250

/* Watchdog's internal commands */
#define CMD_READ_TEMP			0x02	/* Read Temperature; Re-trigger Watchdog */
#define CMD_TRIGGER			CMD_READ_TEMP
#define CMD_GET_STATUS			0x04	/* Get Status Information */
#define CMD_GET_FIRMWARE_VERSION	0x08	/* Get Firmware Version */
#define CMD_GET_DIP_SWITCH_SETTINGS	0x0c	/* Get Dip Switch Settings */
#define CMD_READ_WATCHDOG_TIMEOUT	0x18	/* Read Current Watchdog Time */
#define CMD_WRITE_WATCHDOG_TIMEOUT	0x19	/* Write Current Watchdog Time */
#define CMD_ENABLE_WATCHDOG		0x30	/* Enable / Disable Watchdog */
#define CMD_DISABLE_WATCHDOG		CMD_ENABLE_WATCHDOG

/* Some defines that I like to be somewhere else like include/linux/usb_hid.h */
#define HID_REQ_SET_REPORT		0x09
#define HID_DT_REPORT			(USB_TYPE_CLASS | 0x02)

/* We can only use 1 card due to the /dev/watchdog restriction */
static int cards_found;

/* some internal variables */
static unsigned long is_active;
static char expect_release;

/* Structure to hold all of our device specific stuff */
struct usb_pcwd_private {
	struct usb_device *	udev;			/* save off the usb device pointer */
	struct usb_interface *	interface;		/* the interface for this device */

	unsigned int		interface_number;	/* the interface number used for cmd's */

	unsigned char *		intr_buffer;		/* the buffer to intr data */
	dma_addr_t		intr_dma;		/* the dma address for the intr buffer */
	size_t			intr_size;		/* the size of the intr buffer */
	struct urb *		intr_urb;		/* the urb used for the intr pipe */

	unsigned char		cmd_command;		/* The command that is reported back */
	unsigned char		cmd_data_msb;		/* The data MSB that is reported back */
	unsigned char		cmd_data_lsb;		/* The data LSB that is reported back */
	atomic_t		cmd_received;		/* true if we received a report after a command */

	int			exists;			/* Wether or not the device exists */
	struct semaphore	sem;			/* locks this structure */
};
static struct usb_pcwd_private *usb_pcwd_device;

/* prevent races between open() and disconnect() */
static DECLARE_MUTEX (disconnect_sem);

/* local function prototypes */
static int usb_pcwd_probe	(struct usb_interface *interface, const struct usb_device_id *id);
static void usb_pcwd_disconnect	(struct usb_interface *interface);

/* usb specific object needed to register this driver with the usb subsystem */
static struct usb_driver usb_pcwd_driver = {
	.owner =	THIS_MODULE,
	.name =		DRIVER_NAME,
	.probe =	usb_pcwd_probe,
	.disconnect =	usb_pcwd_disconnect,
	.id_table =	usb_pcwd_table,
};


static void usb_pcwd_intr_done(struct urb *urb, struct pt_regs *regs)
{
	struct usb_pcwd_private *usb_pcwd = (struct usb_pcwd_private *)urb->context;
	unsigned char *data = usb_pcwd->intr_buffer;
	int retval;

	switch (urb->status) {
	case 0:			/* success */
		break;
	case -ECONNRESET:	/* unlink */
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
		return;
	/* -EPIPE:  should clear the halt */
	default:		/* error */
		dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
		goto resubmit;
	}

	dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
		data[0], data[1], data[2]);

	usb_pcwd->cmd_command  = data[0];
	usb_pcwd->cmd_data_msb = data[1];
	usb_pcwd->cmd_data_lsb = data[2];

	/* notify anyone waiting that the cmd has finished */
	atomic_set (&usb_pcwd->cmd_received, 1);

resubmit:
	retval = usb_submit_urb (urb, GFP_ATOMIC);
	if (retval)
		printk(KERN_ERR PFX "can't resubmit intr, usb_submit_urb failed with result %d\n",
			retval);
}

static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd,
	unsigned char *msb, unsigned char *lsb)
{
	int got_response, count;
	unsigned char buf[6];

	/* We will not send any commands if the USB PCWD device does not exist */
	if ((!usb_pcwd) || (!usb_pcwd->exists))
		return -1;

	/* The USB PC Watchdog uses a 6 byte report format. The board currently uses
	 * only 3 of the six bytes of the report. */
	buf[0] = cmd;			/* Byte 0 = CMD */
	buf[1] = *msb;			/* Byte 1 = Data MSB */
	buf[2] = *lsb;			/* Byte 2 = Data LSB */
	buf[3] = buf[4] = buf[5] = 0;	/* All other bytes not used */

	dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
		buf[0], buf[1], buf[2]);

	atomic_set (&usb_pcwd->cmd_received, 0);

	if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
			HID_REQ_SET_REPORT, HID_DT_REPORT,
			0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
			USB_COMMAND_TIMEOUT) != sizeof(buf)) {
		dbg("usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
	}
	/* wait till the usb card processed the command,
	 * with a max. timeout of USB_COMMAND_TIMEOUT */
	got_response = 0;
	for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) {
		mdelay(1);
		if (atomic_read (&usb_pcwd->cmd_received))
			got_response = 1;
	}

	if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
		/* read back response */
		*msb = usb_pcwd->cmd_data_msb;
		*lsb = usb_pcwd->cmd_data_lsb;
	}

	return got_response;
}

static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
{
	unsigned char msb = 0x00;
	unsigned char lsb = 0x00;
	int retval;

	/* Enable Watchdog */
	retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb);

	if ((retval == 0) || (lsb == 0)) {
		printk(KERN_ERR PFX "Card did not acknowledge enable attempt\n");
		return -1;
	}

	return 0;
}

static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
{
	unsigned char msb = 0xA5;
	unsigned char lsb = 0xC3;
	int retval;

	/* Disable Watchdog */
	retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb);

	if ((retval == 0) || (lsb != 0)) {
		printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
		return -1;
	}

	return 0;
}

static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
{
	unsigned char dummy;

	/* Re-trigger Watchdog */
	usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);

	return 0;
}

static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
{
	unsigned char msb = t / 256;
	unsigned char lsb = t % 256;

	if ((t < 0x0001) || (t > 0xFFFF))
		return -EINVAL;

	/* Write new heartbeat to watchdog */
	usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);

	heartbeat = t;
	return 0;
}

static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature)
{
	unsigned char msb, lsb;

	usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);

	/*
	 * Convert celsius to fahrenheit, since this was
	 * the decided 'standard' for this return value.
	 */
	*temperature = (lsb * 9 / 5) + 32;

	return 0;
}

/*
 *	/dev/watchdog handling
 */

static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
			      size_t len, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* note: just in case someone wrote the magic character
			 * five months ago... */
			expect_release = 0;

			/* scan to see whether or not we got the magic character */
			for (i = 0; i != len; i++) {
				char c;
				if(get_user(c, data+i))
					return -EFAULT;
				if (c == 'V')
					expect_release = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		usb_pcwd_keepalive(usb_pcwd_device);
	}
	return len;
}

static int usb_pcwd_ioctl(struct inode *inode, struct file *file,
			  unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static struct watchdog_info ident = {
		.options =		WDIOF_KEEPALIVEPING |
					WDIOF_SETTIMEOUT |
					WDIOF_MAGICCLOSE,
		.firmware_version =	1,
		.identity =		DRIVER_NAME,
	};

	switch (cmd) {
		case WDIOC_GETSUPPORT:
			return copy_to_user(argp, &ident,
				sizeof (ident)) ? -EFAULT : 0;

		case WDIOC_GETSTATUS:
		case WDIOC_GETBOOTSTATUS:
			return put_user(0, p);

		case WDIOC_GETTEMP:
		{
			int temperature;

			if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
				return -EFAULT;

			return put_user(temperature, p);
		}

		case WDIOC_KEEPALIVE:
			usb_pcwd_keepalive(usb_pcwd_device);
			return 0;

		case WDIOC_SETOPTIONS:
		{
			int new_options, retval = -EINVAL;

			if (get_user (new_options, p))
				return -EFAULT;

			if (new_options & WDIOS_DISABLECARD) {
				usb_pcwd_stop(usb_pcwd_device);
				retval = 0;
			}

			if (new_options & WDIOS_ENABLECARD) {
				usb_pcwd_start(usb_pcwd_device);
				retval = 0;
			}

			return retval;
		}

		case WDIOC_SETTIMEOUT:
		{
			int new_heartbeat;

			if (get_user(new_heartbeat, p))
				return -EFAULT;

			if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
			    return -EINVAL;

			usb_pcwd_keepalive(usb_pcwd_device);
			/* Fall */
		}

		case WDIOC_GETTIMEOUT:
			return put_user(heartbeat, p);

		default:
			return -ENOIOCTLCMD;
	}
}

static int usb_pcwd_open(struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */
	if (test_and_set_bit(0, &is_active))
		return -EBUSY;

	/* Activate */
	usb_pcwd_start(usb_pcwd_device);
	usb_pcwd_keepalive(usb_pcwd_device);
	return nonseekable_open(inode, file);
}

static int usb_pcwd_release(struct inode *inode, struct file *file)
{
	/*
	 *      Shut off the timer.
	 */
	if (expect_release == 42) {
		usb_pcwd_stop(usb_pcwd_device);
	} else {
		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
		usb_pcwd_keepalive(usb_pcwd_device);
	}
	expect_release = 0;
	clear_bit(0, &is_active);
	return 0;
}

/*
 *	/dev/temperature handling
 */

static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
				size_t len, loff_t *ppos)
{
	int temperature;

	if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
		return -EFAULT;

	if (copy_to_user(data, &temperature, 1))
		return -EFAULT;

	return 1;
}

static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
{
	return nonseekable_open(inode, file);
}

static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
{
	return 0;
}

/*
 *	Notify system
 */

static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
{
	if (code==SYS_DOWN || code==SYS_HALT) {
		/* Turn the WDT off */
		usb_pcwd_stop(usb_pcwd_device);
	}

	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static struct file_operations usb_pcwd_fops = {
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,
	.write =	usb_pcwd_write,
	.ioctl =	usb_pcwd_ioctl,
	.open =		usb_pcwd_open,
	.release =	usb_pcwd_release,
};

static struct miscdevice usb_pcwd_miscdev = {
	.minor =	WATCHDOG_MINOR,
	.name =		"watchdog",
	.fops =		&usb_pcwd_fops,
};

static struct file_operations usb_pcwd_temperature_fops = {
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,
	.read =		usb_pcwd_temperature_read,
	.open =		usb_pcwd_temperature_open,
	.release =	usb_pcwd_temperature_release,
};

static struct miscdevice usb_pcwd_temperature_miscdev = {
	.minor =	TEMP_MINOR,
	.name =		"temperature",
	.fops =		&usb_pcwd_temperature_fops,
};

static struct notifier_block usb_pcwd_notifier = {
	.notifier_call =	usb_pcwd_notify_sys,
};

/**
 *	usb_pcwd_delete
 */
static inline void usb_pcwd_delete (struct usb_pcwd_private *usb_pcwd)
{
	if (usb_pcwd->intr_urb != NULL)
		usb_free_urb (usb_pcwd->intr_urb);
	if (usb_pcwd->intr_buffer != NULL)
		usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
				usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
	kfree (usb_pcwd);
}

/**
 *	usb_pcwd_probe
 *
 *	Called by the usb core when a new device is connected that it thinks
 *	this driver might be interested in.
 */
static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
	struct usb_device *udev = interface_to_usbdev(interface);
	struct usb_host_interface *iface_desc;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_pcwd_private *usb_pcwd = NULL;
	int pipe, maxp;
	int retval = -ENOMEM;
	int got_fw_rev;
	unsigned char fw_rev_major, fw_rev_minor;
	char fw_ver_str[20];
	unsigned char option_switches, dummy;

	cards_found++;
	if (cards_found > 1) {
		printk(KERN_ERR PFX "This driver only supports 1 device\n");
		return -ENODEV;
	}

	/* get the active interface descriptor */
	iface_desc = interface->cur_altsetting;

	/* check out that we have a HID device */
	if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
		printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
		return -ENODEV;
	}

	/* check out the endpoint: it has to be Interrupt & IN */
	endpoint = &iface_desc->endpoint[0].desc;

	if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
	     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
				== USB_ENDPOINT_XFER_INT))) {
		/* we didn't find a Interrupt endpoint with direction IN */
		printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
		return -ENODEV;
	}

	/* get a handle to the interrupt data pipe */
	pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
	maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));

	/* allocate memory for our device and initialize it */
	usb_pcwd = kmalloc (sizeof(struct usb_pcwd_private), GFP_KERNEL);
	if (usb_pcwd == NULL) {
		printk(KERN_ERR PFX "Out of memory\n");
		goto error;
	}
	memset (usb_pcwd, 0x00, sizeof (*usb_pcwd));

	usb_pcwd_device = usb_pcwd;

	init_MUTEX (&usb_pcwd->sem);
	usb_pcwd->udev = udev;
	usb_pcwd->interface = interface;
	usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
	usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);

	/* set up the memory buffer's */
	if (!(usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, SLAB_ATOMIC, &usb_pcwd->intr_dma))) {
		printk(KERN_ERR PFX "Out of memory\n");
		goto error;
	}

	/* allocate the urb's */
	usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!usb_pcwd->intr_urb) {
		printk(KERN_ERR PFX "Out of memory\n");
		goto error;
	}

	/* initialise the intr urb's */
	usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
			usb_pcwd->intr_buffer, usb_pcwd->intr_size,
			usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
	usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
	usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	/* register our interrupt URB with the USB system */
	if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
		printk(KERN_ERR PFX "Problem registering interrupt URB\n");
		retval = -EIO; /* failure */
		goto error;
	}

	/* The device exists and can be communicated with */
	usb_pcwd->exists = 1;

	/* disable card */
	usb_pcwd_stop(usb_pcwd);

	/* Get the Firmware Version */
	got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
	if (got_fw_rev) {
		sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
	} else {
		sprintf(fw_ver_str, "<card no answer>");
	}

	printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
		fw_ver_str);

	/* Get switch settings */
	usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);

	printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
		option_switches,
		((option_switches & 0x10) ? "ON" : "OFF"),
		((option_switches & 0x08) ? "ON" : "OFF"));

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
	if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
		usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
		printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
			WATCHDOG_HEARTBEAT);
	}

	retval = register_reboot_notifier(&usb_pcwd_notifier);
	if (retval != 0) {
		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
			retval);
		goto error;
	}

	retval = misc_register(&usb_pcwd_temperature_miscdev);
	if (retval != 0) {
		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			TEMP_MINOR, retval);
		goto err_out_unregister_reboot;
	}

	retval = misc_register(&usb_pcwd_miscdev);
	if (retval != 0) {
		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, retval);
		goto err_out_misc_deregister;
	}

	/* we can register the device now, as it is ready */
	usb_set_intfdata (interface, usb_pcwd);

	printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
		heartbeat, nowayout);

	return 0;

err_out_misc_deregister:
	misc_deregister(&usb_pcwd_temperature_miscdev);
err_out_unregister_reboot:
	unregister_reboot_notifier(&usb_pcwd_notifier);
error:
	usb_pcwd_delete (usb_pcwd);
	usb_pcwd_device = NULL;
	return retval;
}


/**
 *	usb_pcwd_disconnect
 *
 *	Called by the usb core when the device is removed from the system.
 *
 *	This routine guarantees that the driver will not submit any more urbs
 *	by clearing dev->udev.
 */
static void usb_pcwd_disconnect(struct usb_interface *interface)
{
	struct usb_pcwd_private *usb_pcwd;

	/* prevent races with open() */
	down (&disconnect_sem);

	usb_pcwd = usb_get_intfdata (interface);
	usb_set_intfdata (interface, NULL);

	down (&usb_pcwd->sem);

	/* Stop the timer before we leave */
	if (!nowayout)
		usb_pcwd_stop(usb_pcwd);

	/* We should now stop communicating with the USB PCWD device */
	usb_pcwd->exists = 0;

	/* Deregister */
	misc_deregister(&usb_pcwd_miscdev);
	misc_deregister(&usb_pcwd_temperature_miscdev);
	unregister_reboot_notifier(&usb_pcwd_notifier);

	up (&usb_pcwd->sem);

	/* Delete the USB PCWD device */
	usb_pcwd_delete(usb_pcwd);

	cards_found--;

	up (&disconnect_sem);

	printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
}



/**
 *	usb_pcwd_init
 */
static int __init usb_pcwd_init(void)
{
	int result;

	/* register this driver with the USB subsystem */
	result = usb_register(&usb_pcwd_driver);
	if (result) {
		printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
		    result);
		return result;
	}

	printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
	return 0;
}


/**
 *	usb_pcwd_exit
 */
static void __exit usb_pcwd_exit(void)
{
	/* deregister this driver with the USB subsystem */
	usb_deregister(&usb_pcwd_driver);
}


module_init (usb_pcwd_init);
module_exit (usb_pcwd_exit);