1// SPDX-License-Identifier: GPL-2.0+
2/*
3 *	Berkshire USB-PC Watchdog Card Driver
4 *
5 *	(c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
6 *
7 *	Based on source code of the following authors:
8 *	  Ken Hollis <kenji@bitgate.com>,
9 *	  Alan Cox <alan@lxorguk.ukuu.org.uk>,
10 *	  Matt Domsch <Matt_Domsch@dell.com>,
11 *	  Rob Radez <rob@osinvestor.com>,
12 *	  Greg Kroah-Hartman <greg@kroah.com>
13 *
14 *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
15 *	provide warranty for any of this software. This material is
16 *	provided "AS-IS" and at no charge.
17 *
18 *	Thanks also to Simon Machell at Berkshire Products Inc. for
19 *	providing the test hardware. More info is available at
20 *	http://www.berkprod.com/ or http://www.pcwatchdog.com/
21 */
22
23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25#include <linux/module.h>	/* For module specific items */
26#include <linux/moduleparam.h>	/* For new moduleparam's */
27#include <linux/types.h>	/* For standard types (like size_t) */
28#include <linux/errno.h>	/* For the -ENODEV/... values */
29#include <linux/kernel.h>	/* For printk/panic/... */
30#include <linux/delay.h>	/* For mdelay function */
31#include <linux/miscdevice.h>	/* For struct miscdevice */
32#include <linux/watchdog.h>	/* For the watchdog specific items */
33#include <linux/notifier.h>	/* For notifier support */
34#include <linux/reboot.h>	/* For reboot_notifier stuff */
35#include <linux/init.h>		/* For __init/__exit/... */
36#include <linux/fs.h>		/* For file operations */
37#include <linux/usb.h>		/* For USB functions */
38#include <linux/slab.h>		/* For kmalloc, ... */
39#include <linux/mutex.h>	/* For mutex locking */
40#include <linux/hid.h>		/* For HID_REQ_SET_REPORT & HID_DT_REPORT */
41#include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
42
43
44/* Module and Version Information */
45#define DRIVER_VERSION "1.02"
46#define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
47#define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
48#define DRIVER_NAME "pcwd_usb"
49
50MODULE_AUTHOR(DRIVER_AUTHOR);
51MODULE_DESCRIPTION(DRIVER_DESC);
52MODULE_LICENSE("GPL");
53
54#define WATCHDOG_HEARTBEAT 0	/* default heartbeat =
55						delay-time from dip-switches */
56static int heartbeat = WATCHDOG_HEARTBEAT;
57module_param(heartbeat, int, 0);
58MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
59	"(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
60				__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
61
62static bool nowayout = WATCHDOG_NOWAYOUT;
63module_param(nowayout, bool, 0);
64MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
65				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
66
67/* The vendor and product id's for the USB-PC Watchdog card */
68#define USB_PCWD_VENDOR_ID	0x0c98
69#define USB_PCWD_PRODUCT_ID	0x1140
70
71/* table of devices that work with this driver */
72static const struct usb_device_id usb_pcwd_table[] = {
73	{ USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
74	{ }					/* Terminating entry */
75};
76MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
77
78/* according to documentation max. time to process a command for the USB
79 * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
80#define USB_COMMAND_TIMEOUT	250
81
82/* Watchdog's internal commands */
83#define CMD_READ_TEMP			0x02	/* Read Temperature;
84							Re-trigger Watchdog */
85#define CMD_TRIGGER			CMD_READ_TEMP
86#define CMD_GET_STATUS			0x04	/* Get Status Information */
87#define CMD_GET_FIRMWARE_VERSION	0x08	/* Get Firmware Version */
88#define CMD_GET_DIP_SWITCH_SETTINGS	0x0c	/* Get Dip Switch Settings */
89#define CMD_READ_WATCHDOG_TIMEOUT	0x18	/* Read Current Watchdog Time */
90#define CMD_WRITE_WATCHDOG_TIMEOUT	0x19	/* Write Current WatchdogTime */
91#define CMD_ENABLE_WATCHDOG		0x30	/* Enable / Disable Watchdog */
92#define CMD_DISABLE_WATCHDOG		CMD_ENABLE_WATCHDOG
93
94/* Watchdog's Dip Switch heartbeat values */
95static const int heartbeat_tbl[] = {
96	5,	/* OFF-OFF-OFF	=  5 Sec  */
97	10,	/* OFF-OFF-ON	= 10 Sec  */
98	30,	/* OFF-ON-OFF	= 30 Sec  */
99	60,	/* OFF-ON-ON	=  1 Min  */
100	300,	/* ON-OFF-OFF	=  5 Min  */
101	600,	/* ON-OFF-ON	= 10 Min  */
102	1800,	/* ON-ON-OFF	= 30 Min  */
103	3600,	/* ON-ON-ON	=  1 hour */
104};
105
106/* We can only use 1 card due to the /dev/watchdog restriction */
107static int cards_found;
108
109/* some internal variables */
110static unsigned long is_active;
111static char expect_release;
112
113/* Structure to hold all of our device specific stuff */
114struct usb_pcwd_private {
115	/* save off the usb device pointer */
116	struct usb_device	*udev;
117	/* the interface for this device */
118	struct usb_interface	*interface;
119
120	/* the interface number used for cmd's */
121	unsigned int		interface_number;
122
123	/* the buffer to intr data */
124	unsigned char		*intr_buffer;
125	/* the dma address for the intr buffer */
126	dma_addr_t		intr_dma;
127	/* the size of the intr buffer */
128	size_t			intr_size;
129	/* the urb used for the intr pipe */
130	struct urb		*intr_urb;
131
132	/* The command that is reported back */
133	unsigned char		cmd_command;
134	/* The data MSB that is reported back */
135	unsigned char		cmd_data_msb;
136	/* The data LSB that is reported back */
137	unsigned char		cmd_data_lsb;
138	/* true if we received a report after a command */
139	atomic_t		cmd_received;
140
141	/* Wether or not the device exists */
142	int			exists;
143	/* locks this structure */
144	struct mutex		mtx;
145};
146static struct usb_pcwd_private *usb_pcwd_device;
147
148/* prevent races between open() and disconnect() */
149static DEFINE_MUTEX(disconnect_mutex);
150
151/* local function prototypes */
152static int usb_pcwd_probe(struct usb_interface *interface,
153						const struct usb_device_id *id);
154static void usb_pcwd_disconnect(struct usb_interface *interface);
155
156/* usb specific object needed to register this driver with the usb subsystem */
157static struct usb_driver usb_pcwd_driver = {
158	.name =		DRIVER_NAME,
159	.probe =	usb_pcwd_probe,
160	.disconnect =	usb_pcwd_disconnect,
161	.id_table =	usb_pcwd_table,
162};
163
164
165static void usb_pcwd_intr_done(struct urb *urb)
166{
167	struct usb_pcwd_private *usb_pcwd =
168				(struct usb_pcwd_private *)urb->context;
169	unsigned char *data = usb_pcwd->intr_buffer;
170	struct device *dev = &usb_pcwd->interface->dev;
171	int retval;
172
173	switch (urb->status) {
174	case 0:			/* success */
175		break;
176	case -ECONNRESET:	/* unlink */
177	case -ENOENT:
178	case -ESHUTDOWN:
179		/* this urb is terminated, clean up */
180		dev_dbg(dev, "%s - urb shutting down with status: %d",
181			__func__, urb->status);
182		return;
183	/* -EPIPE:  should clear the halt */
184	default:		/* error */
185		dev_dbg(dev, "%s - nonzero urb status received: %d",
186			__func__, urb->status);
187		goto resubmit;
188	}
189
190	dev_dbg(dev, "received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
191		data[0], data[1], data[2]);
192
193	usb_pcwd->cmd_command  = data[0];
194	usb_pcwd->cmd_data_msb = data[1];
195	usb_pcwd->cmd_data_lsb = data[2];
196
197	/* notify anyone waiting that the cmd has finished */
198	atomic_set(&usb_pcwd->cmd_received, 1);
199
200resubmit:
201	retval = usb_submit_urb(urb, GFP_ATOMIC);
202	if (retval)
203		pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n",
204		       retval);
205}
206
207static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
208		unsigned char cmd, unsigned char *msb, unsigned char *lsb)
209{
210	int got_response, count;
211	unsigned char *buf;
212
213	/* We will not send any commands if the USB PCWD device does
214	 * not exist */
215	if ((!usb_pcwd) || (!usb_pcwd->exists))
216		return -1;
217
218	buf = kmalloc(6, GFP_KERNEL);
219	if (buf == NULL)
220		return 0;
221
222	/* The USB PC Watchdog uses a 6 byte report format.
223	 * The board currently uses only 3 of the six bytes of the report. */
224	buf[0] = cmd;			/* Byte 0 = CMD */
225	buf[1] = *msb;			/* Byte 1 = Data MSB */
226	buf[2] = *lsb;			/* Byte 2 = Data LSB */
227	buf[3] = buf[4] = buf[5] = 0;	/* All other bytes not used */
228
229	dev_dbg(&usb_pcwd->interface->dev,
230		"sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
231		buf[0], buf[1], buf[2]);
232
233	atomic_set(&usb_pcwd->cmd_received, 0);
234
235	if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
236			HID_REQ_SET_REPORT, HID_DT_REPORT,
237			0x0200, usb_pcwd->interface_number, buf, 6,
238			USB_COMMAND_TIMEOUT) != 6) {
239		dev_dbg(&usb_pcwd->interface->dev,
240			"usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n",
241			cmd, *msb, *lsb);
242	}
243	/* wait till the usb card processed the command,
244	 * with a max. timeout of USB_COMMAND_TIMEOUT */
245	got_response = 0;
246	for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
247								count++) {
248		mdelay(1);
249		if (atomic_read(&usb_pcwd->cmd_received))
250			got_response = 1;
251	}
252
253	if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
254		/* read back response */
255		*msb = usb_pcwd->cmd_data_msb;
256		*lsb = usb_pcwd->cmd_data_lsb;
257	}
258
259	kfree(buf);
260
261	return got_response;
262}
263
264static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
265{
266	unsigned char msb = 0x00;
267	unsigned char lsb = 0x00;
268	int retval;
269
270	/* Enable Watchdog */
271	retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
272								&msb, &lsb);
273
274	if ((retval == 0) || (lsb == 0)) {
275		pr_err("Card did not acknowledge enable attempt\n");
276		return -1;
277	}
278
279	return 0;
280}
281
282static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
283{
284	unsigned char msb = 0xA5;
285	unsigned char lsb = 0xC3;
286	int retval;
287
288	/* Disable Watchdog */
289	retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
290								&msb, &lsb);
291
292	if ((retval == 0) || (lsb != 0)) {
293		pr_err("Card did not acknowledge disable attempt\n");
294		return -1;
295	}
296
297	return 0;
298}
299
300static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
301{
302	unsigned char dummy;
303
304	/* Re-trigger Watchdog */
305	usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
306
307	return 0;
308}
309
310static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
311{
312	unsigned char msb = t / 256;
313	unsigned char lsb = t % 256;
314
315	if ((t < 0x0001) || (t > 0xFFFF))
316		return -EINVAL;
317
318	/* Write new heartbeat to watchdog */
319	usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
320
321	heartbeat = t;
322	return 0;
323}
324
325static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
326							int *temperature)
327{
328	unsigned char msb = 0x00;
329	unsigned char lsb = 0x00;
330
331	usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
332
333	/*
334	 * Convert celsius to fahrenheit, since this was
335	 * the decided 'standard' for this return value.
336	 */
337	*temperature = (lsb * 9 / 5) + 32;
338
339	return 0;
340}
341
342static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
343								int *time_left)
344{
345	unsigned char msb = 0x00;
346	unsigned char lsb = 0x00;
347
348	/* Read the time that's left before rebooting */
349	/* Note: if the board is not yet armed then we will read 0xFFFF */
350	usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
351
352	*time_left = (msb << 8) + lsb;
353
354	return 0;
355}
356
357/*
358 *	/dev/watchdog handling
359 */
360
361static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
362						size_t len, loff_t *ppos)
363{
364	/* See if we got the magic character 'V' and reload the timer */
365	if (len) {
366		if (!nowayout) {
367			size_t i;
368
369			/* note: just in case someone wrote the magic character
370			 * five months ago... */
371			expect_release = 0;
372
373			/* scan to see whether or not we got the
374			 * magic character */
375			for (i = 0; i != len; i++) {
376				char c;
377				if (get_user(c, data + i))
378					return -EFAULT;
379				if (c == 'V')
380					expect_release = 42;
381			}
382		}
383
384		/* someone wrote to us, we should reload the timer */
385		usb_pcwd_keepalive(usb_pcwd_device);
386	}
387	return len;
388}
389
390static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
391						unsigned long arg)
392{
393	void __user *argp = (void __user *)arg;
394	int __user *p = argp;
395	static const struct watchdog_info ident = {
396		.options =		WDIOF_KEEPALIVEPING |
397					WDIOF_SETTIMEOUT |
398					WDIOF_MAGICCLOSE,
399		.firmware_version =	1,
400		.identity =		DRIVER_NAME,
401	};
402
403	switch (cmd) {
404	case WDIOC_GETSUPPORT:
405		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
406
407	case WDIOC_GETSTATUS:
408	case WDIOC_GETBOOTSTATUS:
409		return put_user(0, p);
410
411	case WDIOC_GETTEMP:
412	{
413		int temperature;
414
415		if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
416			return -EFAULT;
417
418		return put_user(temperature, p);
419	}
420
421	case WDIOC_SETOPTIONS:
422	{
423		int new_options, retval = -EINVAL;
424
425		if (get_user(new_options, p))
426			return -EFAULT;
427
428		if (new_options & WDIOS_DISABLECARD) {
429			usb_pcwd_stop(usb_pcwd_device);
430			retval = 0;
431		}
432
433		if (new_options & WDIOS_ENABLECARD) {
434			usb_pcwd_start(usb_pcwd_device);
435			retval = 0;
436		}
437
438		return retval;
439	}
440
441	case WDIOC_KEEPALIVE:
442		usb_pcwd_keepalive(usb_pcwd_device);
443		return 0;
444
445	case WDIOC_SETTIMEOUT:
446	{
447		int new_heartbeat;
448
449		if (get_user(new_heartbeat, p))
450			return -EFAULT;
451
452		if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
453			return -EINVAL;
454
455		usb_pcwd_keepalive(usb_pcwd_device);
456	}
457		fallthrough;
458
459	case WDIOC_GETTIMEOUT:
460		return put_user(heartbeat, p);
461
462	case WDIOC_GETTIMELEFT:
463	{
464		int time_left;
465
466		if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
467			return -EFAULT;
468
469		return put_user(time_left, p);
470	}
471
472	default:
473		return -ENOTTY;
474	}
475}
476
477static int usb_pcwd_open(struct inode *inode, struct file *file)
478{
479	/* /dev/watchdog can only be opened once */
480	if (test_and_set_bit(0, &is_active))
481		return -EBUSY;
482
483	/* Activate */
484	usb_pcwd_start(usb_pcwd_device);
485	usb_pcwd_keepalive(usb_pcwd_device);
486	return stream_open(inode, file);
487}
488
489static int usb_pcwd_release(struct inode *inode, struct file *file)
490{
491	/*
492	 *      Shut off the timer.
493	 */
494	if (expect_release == 42) {
495		usb_pcwd_stop(usb_pcwd_device);
496	} else {
497		pr_crit("Unexpected close, not stopping watchdog!\n");
498		usb_pcwd_keepalive(usb_pcwd_device);
499	}
500	expect_release = 0;
501	clear_bit(0, &is_active);
502	return 0;
503}
504
505/*
506 *	/dev/temperature handling
507 */
508
509static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
510				size_t len, loff_t *ppos)
511{
512	int temperature;
513
514	if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
515		return -EFAULT;
516
517	if (copy_to_user(data, &temperature, 1))
518		return -EFAULT;
519
520	return 1;
521}
522
523static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
524{
525	return stream_open(inode, file);
526}
527
528static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
529{
530	return 0;
531}
532
533/*
534 *	Notify system
535 */
536
537static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
538								void *unused)
539{
540	if (code == SYS_DOWN || code == SYS_HALT)
541		usb_pcwd_stop(usb_pcwd_device);	/* Turn the WDT off */
542
543	return NOTIFY_DONE;
544}
545
546/*
547 *	Kernel Interfaces
548 */
549
550static const struct file_operations usb_pcwd_fops = {
551	.owner =	THIS_MODULE,
552	.llseek =	no_llseek,
553	.write =	usb_pcwd_write,
554	.unlocked_ioctl = usb_pcwd_ioctl,
555	.compat_ioctl = compat_ptr_ioctl,
556	.open =		usb_pcwd_open,
557	.release =	usb_pcwd_release,
558};
559
560static struct miscdevice usb_pcwd_miscdev = {
561	.minor =	WATCHDOG_MINOR,
562	.name =		"watchdog",
563	.fops =		&usb_pcwd_fops,
564};
565
566static const struct file_operations usb_pcwd_temperature_fops = {
567	.owner =	THIS_MODULE,
568	.llseek =	no_llseek,
569	.read =		usb_pcwd_temperature_read,
570	.open =		usb_pcwd_temperature_open,
571	.release =	usb_pcwd_temperature_release,
572};
573
574static struct miscdevice usb_pcwd_temperature_miscdev = {
575	.minor =	TEMP_MINOR,
576	.name =		"temperature",
577	.fops =		&usb_pcwd_temperature_fops,
578};
579
580static struct notifier_block usb_pcwd_notifier = {
581	.notifier_call =	usb_pcwd_notify_sys,
582};
583
584/**
585 *	usb_pcwd_delete
586 */
587static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
588{
589	usb_free_urb(usb_pcwd->intr_urb);
590	usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
591			  usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
592	kfree(usb_pcwd);
593}
594
595/**
596 *	usb_pcwd_probe
597 *
598 *	Called by the usb core when a new device is connected that it thinks
599 *	this driver might be interested in.
600 */
601static int usb_pcwd_probe(struct usb_interface *interface,
602						const struct usb_device_id *id)
603{
604	struct usb_device *udev = interface_to_usbdev(interface);
605	struct usb_host_interface *iface_desc;
606	struct usb_endpoint_descriptor *endpoint;
607	struct usb_pcwd_private *usb_pcwd = NULL;
608	int pipe;
609	int retval = -ENOMEM;
610	int got_fw_rev;
611	unsigned char fw_rev_major, fw_rev_minor;
612	char fw_ver_str[20];
613	unsigned char option_switches, dummy;
614
615	cards_found++;
616	if (cards_found > 1) {
617		pr_err("This driver only supports 1 device\n");
618		return -ENODEV;
619	}
620
621	/* get the active interface descriptor */
622	iface_desc = interface->cur_altsetting;
623
624	/* check out that we have a HID device */
625	if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
626		pr_err("The device isn't a Human Interface Device\n");
627		return -ENODEV;
628	}
629
630	if (iface_desc->desc.bNumEndpoints < 1)
631		return -ENODEV;
632
633	/* check out the endpoint: it has to be Interrupt & IN */
634	endpoint = &iface_desc->endpoint[0].desc;
635
636	if (!usb_endpoint_is_int_in(endpoint)) {
637		/* we didn't find a Interrupt endpoint with direction IN */
638		pr_err("Couldn't find an INTR & IN endpoint\n");
639		return -ENODEV;
640	}
641
642	/* get a handle to the interrupt data pipe */
643	pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
644
645	/* allocate memory for our device and initialize it */
646	usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
647	if (usb_pcwd == NULL)
648		goto error;
649
650	usb_pcwd_device = usb_pcwd;
651
652	mutex_init(&usb_pcwd->mtx);
653	usb_pcwd->udev = udev;
654	usb_pcwd->interface = interface;
655	usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
656	usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
657				le16_to_cpu(endpoint->wMaxPacketSize) : 8);
658
659	/* set up the memory buffer's */
660	usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
661					GFP_KERNEL, &usb_pcwd->intr_dma);
662	if (!usb_pcwd->intr_buffer) {
663		pr_err("Out of memory\n");
664		goto error;
665	}
666
667	/* allocate the urb's */
668	usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
669	if (!usb_pcwd->intr_urb)
670		goto error;
671
672	/* initialise the intr urb's */
673	usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
674			usb_pcwd->intr_buffer, usb_pcwd->intr_size,
675			usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
676	usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
677	usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
678
679	/* register our interrupt URB with the USB system */
680	if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
681		pr_err("Problem registering interrupt URB\n");
682		retval = -EIO; /* failure */
683		goto error;
684	}
685
686	/* The device exists and can be communicated with */
687	usb_pcwd->exists = 1;
688
689	/* disable card */
690	usb_pcwd_stop(usb_pcwd);
691
692	/* Get the Firmware Version */
693	got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
694						&fw_rev_major, &fw_rev_minor);
695	if (got_fw_rev)
696		sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
697	else
698		sprintf(fw_ver_str, "<card no answer>");
699
700	pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str);
701
702	/* Get switch settings */
703	usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
704							&option_switches);
705
706	pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
707		option_switches,
708		((option_switches & 0x10) ? "ON" : "OFF"),
709		((option_switches & 0x08) ? "ON" : "OFF"));
710
711	/* If heartbeat = 0 then we use the heartbeat from the dip-switches */
712	if (heartbeat == 0)
713		heartbeat = heartbeat_tbl[(option_switches & 0x07)];
714
715	/* Check that the heartbeat value is within it's range ;
716	 * if not reset to the default */
717	if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
718		usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
719		pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
720			WATCHDOG_HEARTBEAT);
721	}
722
723	retval = register_reboot_notifier(&usb_pcwd_notifier);
724	if (retval != 0) {
725		pr_err("cannot register reboot notifier (err=%d)\n", retval);
726		goto error;
727	}
728
729	retval = misc_register(&usb_pcwd_temperature_miscdev);
730	if (retval != 0) {
731		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
732		       TEMP_MINOR, retval);
733		goto err_out_unregister_reboot;
734	}
735
736	retval = misc_register(&usb_pcwd_miscdev);
737	if (retval != 0) {
738		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
739		       WATCHDOG_MINOR, retval);
740		goto err_out_misc_deregister;
741	}
742
743	/* we can register the device now, as it is ready */
744	usb_set_intfdata(interface, usb_pcwd);
745
746	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
747		heartbeat, nowayout);
748
749	return 0;
750
751err_out_misc_deregister:
752	misc_deregister(&usb_pcwd_temperature_miscdev);
753err_out_unregister_reboot:
754	unregister_reboot_notifier(&usb_pcwd_notifier);
755error:
756	if (usb_pcwd)
757		usb_pcwd_delete(usb_pcwd);
758	usb_pcwd_device = NULL;
759	return retval;
760}
761
762
763/**
764 *	usb_pcwd_disconnect
765 *
766 *	Called by the usb core when the device is removed from the system.
767 *
768 *	This routine guarantees that the driver will not submit any more urbs
769 *	by clearing dev->udev.
770 */
771static void usb_pcwd_disconnect(struct usb_interface *interface)
772{
773	struct usb_pcwd_private *usb_pcwd;
774
775	/* prevent races with open() */
776	mutex_lock(&disconnect_mutex);
777
778	usb_pcwd = usb_get_intfdata(interface);
779	usb_set_intfdata(interface, NULL);
780
781	mutex_lock(&usb_pcwd->mtx);
782
783	/* Stop the timer before we leave */
784	if (!nowayout)
785		usb_pcwd_stop(usb_pcwd);
786
787	/* We should now stop communicating with the USB PCWD device */
788	usb_pcwd->exists = 0;
789
790	/* Deregister */
791	misc_deregister(&usb_pcwd_miscdev);
792	misc_deregister(&usb_pcwd_temperature_miscdev);
793	unregister_reboot_notifier(&usb_pcwd_notifier);
794
795	mutex_unlock(&usb_pcwd->mtx);
796
797	/* Delete the USB PCWD device */
798	usb_pcwd_delete(usb_pcwd);
799
800	cards_found--;
801
802	mutex_unlock(&disconnect_mutex);
803
804	pr_info("USB PC Watchdog disconnected\n");
805}
806
807module_usb_driver(usb_pcwd_driver);
808