1 /*
2  *	Berkshire USB-PC Watchdog Card Driver
3  *
4  *	(c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
5  *
6  *	Based on source code of the following authors:
7  *	  Ken Hollis <kenji@bitgate.com>,
8  *	  Alan Cox <alan@lxorguk.ukuu.org.uk>,
9  *	  Matt Domsch <Matt_Domsch@dell.com>,
10  *	  Rob Radez <rob@osinvestor.com>,
11  *	  Greg Kroah-Hartman <greg@kroah.com>
12  *
13  *	This program is free software; you can redistribute it and/or
14  *	modify it under the terms of the GNU General Public License
15  *	as published by the Free Software Foundation; either version
16  *	2 of the License, or (at your option) any later version.
17  *
18  *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
19  *	provide warranty for any of this software. This material is
20  *	provided "AS-IS" and at no charge.
21  *
22  *	Thanks also to Simon Machell at Berkshire Products Inc. for
23  *	providing the test hardware. More info is available at
24  *	http://www.berkprod.com/ or http://www.pcwatchdog.com/
25  */
26 
27 #include <linux/module.h>	/* For module specific items */
28 #include <linux/moduleparam.h>	/* For new moduleparam's */
29 #include <linux/types.h>	/* For standard types (like size_t) */
30 #include <linux/errno.h>	/* For the -ENODEV/... values */
31 #include <linux/kernel.h>	/* For printk/panic/... */
32 #include <linux/delay.h>	/* For mdelay function */
33 #include <linux/miscdevice.h>	/* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
34 #include <linux/watchdog.h>	/* For the watchdog specific items */
35 #include <linux/notifier.h>	/* For notifier support */
36 #include <linux/reboot.h>	/* For reboot_notifier stuff */
37 #include <linux/init.h>		/* For __init/__exit/... */
38 #include <linux/fs.h>		/* For file operations */
39 #include <linux/usb.h>		/* For USB functions */
40 #include <linux/slab.h>		/* For kmalloc, ... */
41 #include <linux/mutex.h>	/* For mutex locking */
42 #include <linux/hid.h>		/* For HID_REQ_SET_REPORT & HID_DT_REPORT */
43 #include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
44 
45 
46 #ifdef CONFIG_USB_DEBUG
47 	static int debug = 1;
48 #else
49 	static int debug;
50 #endif
51 
52 /* Use our own dbg macro */
53 #undef dbg
54 #define dbg(format, arg...) \
55 	do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
56 
57 /* Module and Version Information */
58 #define DRIVER_VERSION "1.02"
59 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
60 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
61 #define DRIVER_LICENSE "GPL"
62 #define DRIVER_NAME "pcwd_usb"
63 #define PFX DRIVER_NAME ": "
64 
65 MODULE_AUTHOR(DRIVER_AUTHOR);
66 MODULE_DESCRIPTION(DRIVER_DESC);
67 MODULE_LICENSE(DRIVER_LICENSE);
68 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
69 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
70 
71 /* Module Parameters */
72 module_param(debug, int, 0);
73 MODULE_PARM_DESC(debug, "Debug enabled or not");
74 
75 #define WATCHDOG_HEARTBEAT 0	/* default heartbeat =
76 						delay-time from dip-switches */
77 static int heartbeat = WATCHDOG_HEARTBEAT;
78 module_param(heartbeat, int, 0);
79 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
80 	"(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
81 				__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
82 
83 static int nowayout = WATCHDOG_NOWAYOUT;
84 module_param(nowayout, int, 0);
85 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
86 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
87 
88 /* The vendor and product id's for the USB-PC Watchdog card */
89 #define USB_PCWD_VENDOR_ID	0x0c98
90 #define USB_PCWD_PRODUCT_ID	0x1140
91 
92 /* table of devices that work with this driver */
93 static struct usb_device_id usb_pcwd_table[] = {
94 	{ USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
95 	{ }					/* Terminating entry */
96 };
97 MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
98 
99 /* according to documentation max. time to process a command for the USB
100  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
101 #define USB_COMMAND_TIMEOUT	250
102 
103 /* Watchdog's internal commands */
104 #define CMD_READ_TEMP			0x02	/* Read Temperature;
105 							Re-trigger Watchdog */
106 #define CMD_TRIGGER			CMD_READ_TEMP
107 #define CMD_GET_STATUS			0x04	/* Get Status Information */
108 #define CMD_GET_FIRMWARE_VERSION	0x08	/* Get Firmware Version */
109 #define CMD_GET_DIP_SWITCH_SETTINGS	0x0c	/* Get Dip Switch Settings */
110 #define CMD_READ_WATCHDOG_TIMEOUT	0x18	/* Read Current Watchdog Time */
111 #define CMD_WRITE_WATCHDOG_TIMEOUT	0x19	/* Write Current WatchdogTime */
112 #define CMD_ENABLE_WATCHDOG		0x30	/* Enable / Disable Watchdog */
113 #define CMD_DISABLE_WATCHDOG		CMD_ENABLE_WATCHDOG
114 
115 /* Watchdog's Dip Switch heartbeat values */
116 static const int heartbeat_tbl[] = {
117 	5,	/* OFF-OFF-OFF	=  5 Sec  */
118 	10,	/* OFF-OFF-ON	= 10 Sec  */
119 	30,	/* OFF-ON-OFF	= 30 Sec  */
120 	60,	/* OFF-ON-ON	=  1 Min  */
121 	300,	/* ON-OFF-OFF	=  5 Min  */
122 	600,	/* ON-OFF-ON	= 10 Min  */
123 	1800,	/* ON-ON-OFF	= 30 Min  */
124 	3600,	/* ON-ON-ON	=  1 hour */
125 };
126 
127 /* We can only use 1 card due to the /dev/watchdog restriction */
128 static int cards_found;
129 
130 /* some internal variables */
131 static unsigned long is_active;
132 static char expect_release;
133 
134 /* Structure to hold all of our device specific stuff */
135 struct usb_pcwd_private {
136 	/* save off the usb device pointer */
137 	struct usb_device	*udev;
138 	/* the interface for this device */
139 	struct usb_interface	*interface;
140 
141 	/* the interface number used for cmd's */
142 	unsigned int		interface_number;
143 
144 	/* the buffer to intr data */
145 	unsigned char		*intr_buffer;
146 	/* the dma address for the intr buffer */
147 	dma_addr_t		intr_dma;
148 	/* the size of the intr buffer */
149 	size_t			intr_size;
150 	/* the urb used for the intr pipe */
151 	struct urb		*intr_urb;
152 
153 	/* The command that is reported back */
154 	unsigned char		cmd_command;
155 	/* The data MSB that is reported back */
156 	unsigned char		cmd_data_msb;
157 	/* The data LSB that is reported back */
158 	unsigned char		cmd_data_lsb;
159 	/* true if we received a report after a command */
160 	atomic_t		cmd_received;
161 
162 	/* Wether or not the device exists */
163 	int			exists;
164 	/* locks this structure */
165 	struct mutex		mtx;
166 };
167 static struct usb_pcwd_private *usb_pcwd_device;
168 
169 /* prevent races between open() and disconnect() */
170 static DEFINE_MUTEX(disconnect_mutex);
171 
172 /* local function prototypes */
173 static int usb_pcwd_probe(struct usb_interface *interface,
174 						const struct usb_device_id *id);
175 static void usb_pcwd_disconnect(struct usb_interface *interface);
176 
177 /* usb specific object needed to register this driver with the usb subsystem */
178 static struct usb_driver usb_pcwd_driver = {
179 	.name =		DRIVER_NAME,
180 	.probe =	usb_pcwd_probe,
181 	.disconnect =	usb_pcwd_disconnect,
182 	.id_table =	usb_pcwd_table,
183 };
184 
185 
usb_pcwd_intr_done(struct urb * urb)186 static void usb_pcwd_intr_done(struct urb *urb)
187 {
188 	struct usb_pcwd_private *usb_pcwd =
189 				(struct usb_pcwd_private *)urb->context;
190 	unsigned char *data = usb_pcwd->intr_buffer;
191 	int retval;
192 
193 	switch (urb->status) {
194 	case 0:			/* success */
195 		break;
196 	case -ECONNRESET:	/* unlink */
197 	case -ENOENT:
198 	case -ESHUTDOWN:
199 		/* this urb is terminated, clean up */
200 		dbg("%s - urb shutting down with status: %d", __func__,
201 								urb->status);
202 		return;
203 	/* -EPIPE:  should clear the halt */
204 	default:		/* error */
205 		dbg("%s - nonzero urb status received: %d", __func__,
206 								urb->status);
207 		goto resubmit;
208 	}
209 
210 	dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
211 		data[0], data[1], data[2]);
212 
213 	usb_pcwd->cmd_command  = data[0];
214 	usb_pcwd->cmd_data_msb = data[1];
215 	usb_pcwd->cmd_data_lsb = data[2];
216 
217 	/* notify anyone waiting that the cmd has finished */
218 	atomic_set(&usb_pcwd->cmd_received, 1);
219 
220 resubmit:
221 	retval = usb_submit_urb(urb, GFP_ATOMIC);
222 	if (retval)
223 		printk(KERN_ERR PFX "can't resubmit intr, "
224 			"usb_submit_urb failed with result %d\n", retval);
225 }
226 
usb_pcwd_send_command(struct usb_pcwd_private * usb_pcwd,unsigned char cmd,unsigned char * msb,unsigned char * lsb)227 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
228 		unsigned char cmd, unsigned char *msb, unsigned char *lsb)
229 {
230 	int got_response, count;
231 	unsigned char buf[6];
232 
233 	/* We will not send any commands if the USB PCWD device does
234 	 * not exist */
235 	if ((!usb_pcwd) || (!usb_pcwd->exists))
236 		return -1;
237 
238 	/* The USB PC Watchdog uses a 6 byte report format.
239 	 * The board currently uses only 3 of the six bytes of the report. */
240 	buf[0] = cmd;			/* Byte 0 = CMD */
241 	buf[1] = *msb;			/* Byte 1 = Data MSB */
242 	buf[2] = *lsb;			/* Byte 2 = Data LSB */
243 	buf[3] = buf[4] = buf[5] = 0;	/* All other bytes not used */
244 
245 	dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
246 		buf[0], buf[1], buf[2]);
247 
248 	atomic_set(&usb_pcwd->cmd_received, 0);
249 
250 	if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
251 			HID_REQ_SET_REPORT, HID_DT_REPORT,
252 			0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
253 			USB_COMMAND_TIMEOUT) != sizeof(buf)) {
254 		dbg("usb_pcwd_send_command: error in usb_control_msg for "
255 				"cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
256 	}
257 	/* wait till the usb card processed the command,
258 	 * with a max. timeout of USB_COMMAND_TIMEOUT */
259 	got_response = 0;
260 	for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
261 								count++) {
262 		mdelay(1);
263 		if (atomic_read(&usb_pcwd->cmd_received))
264 			got_response = 1;
265 	}
266 
267 	if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
268 		/* read back response */
269 		*msb = usb_pcwd->cmd_data_msb;
270 		*lsb = usb_pcwd->cmd_data_lsb;
271 	}
272 
273 	return got_response;
274 }
275 
usb_pcwd_start(struct usb_pcwd_private * usb_pcwd)276 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
277 {
278 	unsigned char msb = 0x00;
279 	unsigned char lsb = 0x00;
280 	int retval;
281 
282 	/* Enable Watchdog */
283 	retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
284 								&msb, &lsb);
285 
286 	if ((retval == 0) || (lsb == 0)) {
287 		printk(KERN_ERR PFX
288 				"Card did not acknowledge enable attempt\n");
289 		return -1;
290 	}
291 
292 	return 0;
293 }
294 
usb_pcwd_stop(struct usb_pcwd_private * usb_pcwd)295 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
296 {
297 	unsigned char msb = 0xA5;
298 	unsigned char lsb = 0xC3;
299 	int retval;
300 
301 	/* Disable Watchdog */
302 	retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
303 								&msb, &lsb);
304 
305 	if ((retval == 0) || (lsb != 0)) {
306 		printk(KERN_ERR PFX
307 			"Card did not acknowledge disable attempt\n");
308 		return -1;
309 	}
310 
311 	return 0;
312 }
313 
usb_pcwd_keepalive(struct usb_pcwd_private * usb_pcwd)314 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
315 {
316 	unsigned char dummy;
317 
318 	/* Re-trigger Watchdog */
319 	usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
320 
321 	return 0;
322 }
323 
usb_pcwd_set_heartbeat(struct usb_pcwd_private * usb_pcwd,int t)324 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
325 {
326 	unsigned char msb = t / 256;
327 	unsigned char lsb = t % 256;
328 
329 	if ((t < 0x0001) || (t > 0xFFFF))
330 		return -EINVAL;
331 
332 	/* Write new heartbeat to watchdog */
333 	usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
334 
335 	heartbeat = t;
336 	return 0;
337 }
338 
usb_pcwd_get_temperature(struct usb_pcwd_private * usb_pcwd,int * temperature)339 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
340 							int *temperature)
341 {
342 	unsigned char msb, lsb;
343 
344 	usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
345 
346 	/*
347 	 * Convert celsius to fahrenheit, since this was
348 	 * the decided 'standard' for this return value.
349 	 */
350 	*temperature = (lsb * 9 / 5) + 32;
351 
352 	return 0;
353 }
354 
usb_pcwd_get_timeleft(struct usb_pcwd_private * usb_pcwd,int * time_left)355 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
356 								int *time_left)
357 {
358 	unsigned char msb, lsb;
359 
360 	/* Read the time that's left before rebooting */
361 	/* Note: if the board is not yet armed then we will read 0xFFFF */
362 	usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
363 
364 	*time_left = (msb << 8) + lsb;
365 
366 	return 0;
367 }
368 
369 /*
370  *	/dev/watchdog handling
371  */
372 
usb_pcwd_write(struct file * file,const char __user * data,size_t len,loff_t * ppos)373 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
374 						size_t len, loff_t *ppos)
375 {
376 	/* See if we got the magic character 'V' and reload the timer */
377 	if (len) {
378 		if (!nowayout) {
379 			size_t i;
380 
381 			/* note: just in case someone wrote the magic character
382 			 * five months ago... */
383 			expect_release = 0;
384 
385 			/* scan to see whether or not we got the
386 			 * magic character */
387 			for (i = 0; i != len; i++) {
388 				char c;
389 				if (get_user(c, data + i))
390 					return -EFAULT;
391 				if (c == 'V')
392 					expect_release = 42;
393 			}
394 		}
395 
396 		/* someone wrote to us, we should reload the timer */
397 		usb_pcwd_keepalive(usb_pcwd_device);
398 	}
399 	return len;
400 }
401 
usb_pcwd_ioctl(struct file * file,unsigned int cmd,unsigned long arg)402 static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
403 						unsigned long arg)
404 {
405 	void __user *argp = (void __user *)arg;
406 	int __user *p = argp;
407 	static const struct watchdog_info ident = {
408 		.options =		WDIOF_KEEPALIVEPING |
409 					WDIOF_SETTIMEOUT |
410 					WDIOF_MAGICCLOSE,
411 		.firmware_version =	1,
412 		.identity =		DRIVER_NAME,
413 	};
414 
415 	switch (cmd) {
416 	case WDIOC_GETSUPPORT:
417 		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
418 
419 	case WDIOC_GETSTATUS:
420 	case WDIOC_GETBOOTSTATUS:
421 		return put_user(0, p);
422 
423 	case WDIOC_GETTEMP:
424 	{
425 		int temperature;
426 
427 		if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
428 			return -EFAULT;
429 
430 		return put_user(temperature, p);
431 	}
432 
433 	case WDIOC_SETOPTIONS:
434 	{
435 		int new_options, retval = -EINVAL;
436 
437 		if (get_user(new_options, p))
438 			return -EFAULT;
439 
440 		if (new_options & WDIOS_DISABLECARD) {
441 			usb_pcwd_stop(usb_pcwd_device);
442 			retval = 0;
443 		}
444 
445 		if (new_options & WDIOS_ENABLECARD) {
446 			usb_pcwd_start(usb_pcwd_device);
447 			retval = 0;
448 		}
449 
450 		return retval;
451 	}
452 
453 	case WDIOC_KEEPALIVE:
454 		usb_pcwd_keepalive(usb_pcwd_device);
455 		return 0;
456 
457 	case WDIOC_SETTIMEOUT:
458 	{
459 		int new_heartbeat;
460 
461 		if (get_user(new_heartbeat, p))
462 			return -EFAULT;
463 
464 		if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
465 			return -EINVAL;
466 
467 		usb_pcwd_keepalive(usb_pcwd_device);
468 		/* Fall */
469 	}
470 
471 	case WDIOC_GETTIMEOUT:
472 		return put_user(heartbeat, p);
473 
474 	case WDIOC_GETTIMELEFT:
475 	{
476 		int time_left;
477 
478 		if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
479 			return -EFAULT;
480 
481 		return put_user(time_left, p);
482 	}
483 
484 	default:
485 		return -ENOTTY;
486 	}
487 }
488 
usb_pcwd_open(struct inode * inode,struct file * file)489 static int usb_pcwd_open(struct inode *inode, struct file *file)
490 {
491 	/* /dev/watchdog can only be opened once */
492 	if (test_and_set_bit(0, &is_active))
493 		return -EBUSY;
494 
495 	/* Activate */
496 	usb_pcwd_start(usb_pcwd_device);
497 	usb_pcwd_keepalive(usb_pcwd_device);
498 	return nonseekable_open(inode, file);
499 }
500 
usb_pcwd_release(struct inode * inode,struct file * file)501 static int usb_pcwd_release(struct inode *inode, struct file *file)
502 {
503 	/*
504 	 *      Shut off the timer.
505 	 */
506 	if (expect_release == 42) {
507 		usb_pcwd_stop(usb_pcwd_device);
508 	} else {
509 		printk(KERN_CRIT PFX
510 			"Unexpected close, not stopping watchdog!\n");
511 		usb_pcwd_keepalive(usb_pcwd_device);
512 	}
513 	expect_release = 0;
514 	clear_bit(0, &is_active);
515 	return 0;
516 }
517 
518 /*
519  *	/dev/temperature handling
520  */
521 
usb_pcwd_temperature_read(struct file * file,char __user * data,size_t len,loff_t * ppos)522 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
523 				size_t len, loff_t *ppos)
524 {
525 	int temperature;
526 
527 	if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
528 		return -EFAULT;
529 
530 	if (copy_to_user(data, &temperature, 1))
531 		return -EFAULT;
532 
533 	return 1;
534 }
535 
usb_pcwd_temperature_open(struct inode * inode,struct file * file)536 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
537 {
538 	return nonseekable_open(inode, file);
539 }
540 
usb_pcwd_temperature_release(struct inode * inode,struct file * file)541 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
542 {
543 	return 0;
544 }
545 
546 /*
547  *	Notify system
548  */
549 
usb_pcwd_notify_sys(struct notifier_block * this,unsigned long code,void * unused)550 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
551 								void *unused)
552 {
553 	if (code == SYS_DOWN || code == SYS_HALT)
554 		usb_pcwd_stop(usb_pcwd_device);	/* Turn the WDT off */
555 
556 	return NOTIFY_DONE;
557 }
558 
559 /*
560  *	Kernel Interfaces
561  */
562 
563 static const struct file_operations usb_pcwd_fops = {
564 	.owner =	THIS_MODULE,
565 	.llseek =	no_llseek,
566 	.write =	usb_pcwd_write,
567 	.unlocked_ioctl = usb_pcwd_ioctl,
568 	.open =		usb_pcwd_open,
569 	.release =	usb_pcwd_release,
570 };
571 
572 static struct miscdevice usb_pcwd_miscdev = {
573 	.minor =	WATCHDOG_MINOR,
574 	.name =		"watchdog",
575 	.fops =		&usb_pcwd_fops,
576 };
577 
578 static const struct file_operations usb_pcwd_temperature_fops = {
579 	.owner =	THIS_MODULE,
580 	.llseek =	no_llseek,
581 	.read =		usb_pcwd_temperature_read,
582 	.open =		usb_pcwd_temperature_open,
583 	.release =	usb_pcwd_temperature_release,
584 };
585 
586 static struct miscdevice usb_pcwd_temperature_miscdev = {
587 	.minor =	TEMP_MINOR,
588 	.name =		"temperature",
589 	.fops =		&usb_pcwd_temperature_fops,
590 };
591 
592 static struct notifier_block usb_pcwd_notifier = {
593 	.notifier_call =	usb_pcwd_notify_sys,
594 };
595 
596 /**
597  *	usb_pcwd_delete
598  */
usb_pcwd_delete(struct usb_pcwd_private * usb_pcwd)599 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
600 {
601 	usb_free_urb(usb_pcwd->intr_urb);
602 	if (usb_pcwd->intr_buffer != NULL)
603 		usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
604 				  usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
605 	kfree(usb_pcwd);
606 }
607 
608 /**
609  *	usb_pcwd_probe
610  *
611  *	Called by the usb core when a new device is connected that it thinks
612  *	this driver might be interested in.
613  */
usb_pcwd_probe(struct usb_interface * interface,const struct usb_device_id * id)614 static int usb_pcwd_probe(struct usb_interface *interface,
615 						const struct usb_device_id *id)
616 {
617 	struct usb_device *udev = interface_to_usbdev(interface);
618 	struct usb_host_interface *iface_desc;
619 	struct usb_endpoint_descriptor *endpoint;
620 	struct usb_pcwd_private *usb_pcwd = NULL;
621 	int pipe, maxp;
622 	int retval = -ENOMEM;
623 	int got_fw_rev;
624 	unsigned char fw_rev_major, fw_rev_minor;
625 	char fw_ver_str[20];
626 	unsigned char option_switches, dummy;
627 
628 	cards_found++;
629 	if (cards_found > 1) {
630 		printk(KERN_ERR PFX "This driver only supports 1 device\n");
631 		return -ENODEV;
632 	}
633 
634 	/* get the active interface descriptor */
635 	iface_desc = interface->cur_altsetting;
636 
637 	/* check out that we have a HID device */
638 	if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
639 		printk(KERN_ERR PFX
640 			"The device isn't a Human Interface Device\n");
641 		return -ENODEV;
642 	}
643 
644 	/* check out the endpoint: it has to be Interrupt & IN */
645 	endpoint = &iface_desc->endpoint[0].desc;
646 
647 	if (!usb_endpoint_is_int_in(endpoint)) {
648 		/* we didn't find a Interrupt endpoint with direction IN */
649 		printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
650 		return -ENODEV;
651 	}
652 
653 	/* get a handle to the interrupt data pipe */
654 	pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
655 	maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
656 
657 	/* allocate memory for our device and initialize it */
658 	usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
659 	if (usb_pcwd == NULL) {
660 		printk(KERN_ERR PFX "Out of memory\n");
661 		goto error;
662 	}
663 
664 	usb_pcwd_device = usb_pcwd;
665 
666 	mutex_init(&usb_pcwd->mtx);
667 	usb_pcwd->udev = udev;
668 	usb_pcwd->interface = interface;
669 	usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
670 	usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
671 				le16_to_cpu(endpoint->wMaxPacketSize) : 8);
672 
673 	/* set up the memory buffer's */
674 	usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
675 					GFP_ATOMIC, &usb_pcwd->intr_dma);
676 	if (!usb_pcwd->intr_buffer) {
677 		printk(KERN_ERR PFX "Out of memory\n");
678 		goto error;
679 	}
680 
681 	/* allocate the urb's */
682 	usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
683 	if (!usb_pcwd->intr_urb) {
684 		printk(KERN_ERR PFX "Out of memory\n");
685 		goto error;
686 	}
687 
688 	/* initialise the intr urb's */
689 	usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
690 			usb_pcwd->intr_buffer, usb_pcwd->intr_size,
691 			usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
692 	usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
693 	usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
694 
695 	/* register our interrupt URB with the USB system */
696 	if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
697 		printk(KERN_ERR PFX "Problem registering interrupt URB\n");
698 		retval = -EIO; /* failure */
699 		goto error;
700 	}
701 
702 	/* The device exists and can be communicated with */
703 	usb_pcwd->exists = 1;
704 
705 	/* disable card */
706 	usb_pcwd_stop(usb_pcwd);
707 
708 	/* Get the Firmware Version */
709 	got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
710 						&fw_rev_major, &fw_rev_minor);
711 	if (got_fw_rev)
712 		sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
713 	else
714 		sprintf(fw_ver_str, "<card no answer>");
715 
716 	printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
717 		fw_ver_str);
718 
719 	/* Get switch settings */
720 	usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
721 							&option_switches);
722 
723 	printk(KERN_INFO PFX "Option switches (0x%02x): "
724 		"Temperature Reset Enable=%s, Power On Delay=%s\n",
725 		option_switches,
726 		((option_switches & 0x10) ? "ON" : "OFF"),
727 		((option_switches & 0x08) ? "ON" : "OFF"));
728 
729 	/* If heartbeat = 0 then we use the heartbeat from the dip-switches */
730 	if (heartbeat == 0)
731 		heartbeat = heartbeat_tbl[(option_switches & 0x07)];
732 
733 	/* Check that the heartbeat value is within it's range ;
734 	 * if not reset to the default */
735 	if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
736 		usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
737 		printk(KERN_INFO PFX
738 			"heartbeat value must be 0<heartbeat<65536, using %d\n",
739 			WATCHDOG_HEARTBEAT);
740 	}
741 
742 	retval = register_reboot_notifier(&usb_pcwd_notifier);
743 	if (retval != 0) {
744 		printk(KERN_ERR PFX
745 			"cannot register reboot notifier (err=%d)\n",
746 			retval);
747 		goto error;
748 	}
749 
750 	retval = misc_register(&usb_pcwd_temperature_miscdev);
751 	if (retval != 0) {
752 		printk(KERN_ERR PFX
753 			"cannot register miscdev on minor=%d (err=%d)\n",
754 			TEMP_MINOR, retval);
755 		goto err_out_unregister_reboot;
756 	}
757 
758 	retval = misc_register(&usb_pcwd_miscdev);
759 	if (retval != 0) {
760 		printk(KERN_ERR PFX
761 			"cannot register miscdev on minor=%d (err=%d)\n",
762 			WATCHDOG_MINOR, retval);
763 		goto err_out_misc_deregister;
764 	}
765 
766 	/* we can register the device now, as it is ready */
767 	usb_set_intfdata(interface, usb_pcwd);
768 
769 	printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
770 		heartbeat, nowayout);
771 
772 	return 0;
773 
774 err_out_misc_deregister:
775 	misc_deregister(&usb_pcwd_temperature_miscdev);
776 err_out_unregister_reboot:
777 	unregister_reboot_notifier(&usb_pcwd_notifier);
778 error:
779 	if (usb_pcwd)
780 		usb_pcwd_delete(usb_pcwd);
781 	usb_pcwd_device = NULL;
782 	return retval;
783 }
784 
785 
786 /**
787  *	usb_pcwd_disconnect
788  *
789  *	Called by the usb core when the device is removed from the system.
790  *
791  *	This routine guarantees that the driver will not submit any more urbs
792  *	by clearing dev->udev.
793  */
usb_pcwd_disconnect(struct usb_interface * interface)794 static void usb_pcwd_disconnect(struct usb_interface *interface)
795 {
796 	struct usb_pcwd_private *usb_pcwd;
797 
798 	/* prevent races with open() */
799 	mutex_lock(&disconnect_mutex);
800 
801 	usb_pcwd = usb_get_intfdata(interface);
802 	usb_set_intfdata(interface, NULL);
803 
804 	mutex_lock(&usb_pcwd->mtx);
805 
806 	/* Stop the timer before we leave */
807 	if (!nowayout)
808 		usb_pcwd_stop(usb_pcwd);
809 
810 	/* We should now stop communicating with the USB PCWD device */
811 	usb_pcwd->exists = 0;
812 
813 	/* Deregister */
814 	misc_deregister(&usb_pcwd_miscdev);
815 	misc_deregister(&usb_pcwd_temperature_miscdev);
816 	unregister_reboot_notifier(&usb_pcwd_notifier);
817 
818 	mutex_unlock(&usb_pcwd->mtx);
819 
820 	/* Delete the USB PCWD device */
821 	usb_pcwd_delete(usb_pcwd);
822 
823 	cards_found--;
824 
825 	mutex_unlock(&disconnect_mutex);
826 
827 	printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
828 }
829 
830 
831 
832 /**
833  *	usb_pcwd_init
834  */
usb_pcwd_init(void)835 static int __init usb_pcwd_init(void)
836 {
837 	int result;
838 
839 	/* register this driver with the USB subsystem */
840 	result = usb_register(&usb_pcwd_driver);
841 	if (result) {
842 		printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
843 		    result);
844 		return result;
845 	}
846 
847 	printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION "\n");
848 	return 0;
849 }
850 
851 
852 /**
853  *	usb_pcwd_exit
854  */
usb_pcwd_exit(void)855 static void __exit usb_pcwd_exit(void)
856 {
857 	/* deregister this driver with the USB subsystem */
858 	usb_deregister(&usb_pcwd_driver);
859 }
860 
861 
862 module_init(usb_pcwd_init);
863 module_exit(usb_pcwd_exit);
864