2 * Berkshire USB-PC Watchdog Card Driver
4 * (c) Copyright 2004 Wim Van Sebroeck <wim@iguana.be>.
6 * Based on source code of the following authors:
7 * Ken Hollis <kenji@bitgate.com>,
8 * Alan Cox <alan@redhat.com>,
9 * Matt Domsch <Matt_Domsch@dell.com>,
10 * Rob Radez <rob@osinvestor.com>,
11 * Greg Kroah-Hartman <greg@kroah.com>
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.
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.
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/
27 #include <linux/kernel.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/slab.h>
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/types.h>
34 #include <linux/delay.h>
35 #include <linux/miscdevice.h>
36 #include <linux/watchdog.h>
37 #include <linux/notifier.h>
38 #include <linux/reboot.h>
40 #include <linux/smp_lock.h>
41 #include <linux/completion.h>
42 #include <asm/uaccess.h>
43 #include <linux/usb.h>
44 #include <linux/mutex.h>
45 #include <linux/hid.h> /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
48 #ifdef CONFIG_USB_DEBUG
54 /* Use our own dbg macro */
56 #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
59 /* Module and Version Information */
60 #define DRIVER_VERSION "1.01"
61 #define DRIVER_DATE "15 Mar 2005"
62 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
63 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
64 #define DRIVER_LICENSE "GPL"
65 #define DRIVER_NAME "pcwd_usb"
66 #define PFX DRIVER_NAME ": "
68 MODULE_AUTHOR(DRIVER_AUTHOR);
69 MODULE_DESCRIPTION(DRIVER_DESC);
70 MODULE_LICENSE(DRIVER_LICENSE);
71 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
72 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
74 /* Module Parameters */
75 module_param(debug, int, 0);
76 MODULE_PARM_DESC(debug, "Debug enabled or not");
78 #define WATCHDOG_HEARTBEAT 2 /* 2 sec default heartbeat */
79 static int heartbeat = WATCHDOG_HEARTBEAT;
80 module_param(heartbeat, int, 0);
81 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
83 static int nowayout = WATCHDOG_NOWAYOUT;
84 module_param(nowayout, int, 0);
85 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
87 /* The vendor and product id's for the USB-PC Watchdog card */
88 #define USB_PCWD_VENDOR_ID 0x0c98
89 #define USB_PCWD_PRODUCT_ID 0x1140
91 /* table of devices that work with this driver */
92 static struct usb_device_id usb_pcwd_table [] = {
93 { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
94 { } /* Terminating entry */
96 MODULE_DEVICE_TABLE (usb, usb_pcwd_table);
98 /* according to documentation max. time to process a command for the USB
99 * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
100 #define USB_COMMAND_TIMEOUT 250
102 /* Watchdog's internal commands */
103 #define CMD_READ_TEMP 0x02 /* Read Temperature; Re-trigger Watchdog */
104 #define CMD_TRIGGER CMD_READ_TEMP
105 #define CMD_GET_STATUS 0x04 /* Get Status Information */
106 #define CMD_GET_FIRMWARE_VERSION 0x08 /* Get Firmware Version */
107 #define CMD_GET_DIP_SWITCH_SETTINGS 0x0c /* Get Dip Switch Settings */
108 #define CMD_READ_WATCHDOG_TIMEOUT 0x18 /* Read Current Watchdog Time */
109 #define CMD_WRITE_WATCHDOG_TIMEOUT 0x19 /* Write Current Watchdog Time */
110 #define CMD_ENABLE_WATCHDOG 0x30 /* Enable / Disable Watchdog */
111 #define CMD_DISABLE_WATCHDOG CMD_ENABLE_WATCHDOG
113 /* We can only use 1 card due to the /dev/watchdog restriction */
114 static int cards_found;
116 /* some internal variables */
117 static unsigned long is_active;
118 static char expect_release;
120 /* Structure to hold all of our device specific stuff */
121 struct usb_pcwd_private {
122 struct usb_device * udev; /* save off the usb device pointer */
123 struct usb_interface * interface; /* the interface for this device */
125 unsigned int interface_number; /* the interface number used for cmd's */
127 unsigned char * intr_buffer; /* the buffer to intr data */
128 dma_addr_t intr_dma; /* the dma address for the intr buffer */
129 size_t intr_size; /* the size of the intr buffer */
130 struct urb * intr_urb; /* the urb used for the intr pipe */
132 unsigned char cmd_command; /* The command that is reported back */
133 unsigned char cmd_data_msb; /* The data MSB that is reported back */
134 unsigned char cmd_data_lsb; /* The data LSB that is reported back */
135 atomic_t cmd_received; /* true if we received a report after a command */
137 int exists; /* Wether or not the device exists */
138 struct semaphore sem; /* locks this structure */
140 static struct usb_pcwd_private *usb_pcwd_device;
142 /* prevent races between open() and disconnect() */
143 static DEFINE_MUTEX(disconnect_mutex);
145 /* local function prototypes */
146 static int usb_pcwd_probe (struct usb_interface *interface, const struct usb_device_id *id);
147 static void usb_pcwd_disconnect (struct usb_interface *interface);
149 /* usb specific object needed to register this driver with the usb subsystem */
150 static struct usb_driver usb_pcwd_driver = {
152 .probe = usb_pcwd_probe,
153 .disconnect = usb_pcwd_disconnect,
154 .id_table = usb_pcwd_table,
158 static void usb_pcwd_intr_done(struct urb *urb)
160 struct usb_pcwd_private *usb_pcwd = (struct usb_pcwd_private *)urb->context;
161 unsigned char *data = usb_pcwd->intr_buffer;
164 switch (urb->status) {
165 case 0: /* success */
167 case -ECONNRESET: /* unlink */
170 /* this urb is terminated, clean up */
171 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
173 /* -EPIPE: should clear the halt */
175 dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
179 dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
180 data[0], data[1], data[2]);
182 usb_pcwd->cmd_command = data[0];
183 usb_pcwd->cmd_data_msb = data[1];
184 usb_pcwd->cmd_data_lsb = data[2];
186 /* notify anyone waiting that the cmd has finished */
187 atomic_set (&usb_pcwd->cmd_received, 1);
190 retval = usb_submit_urb (urb, GFP_ATOMIC);
192 printk(KERN_ERR PFX "can't resubmit intr, usb_submit_urb failed with result %d\n",
196 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd,
197 unsigned char *msb, unsigned char *lsb)
199 int got_response, count;
200 unsigned char buf[6];
202 /* We will not send any commands if the USB PCWD device does not exist */
203 if ((!usb_pcwd) || (!usb_pcwd->exists))
206 /* The USB PC Watchdog uses a 6 byte report format. The board currently uses
207 * only 3 of the six bytes of the report. */
208 buf[0] = cmd; /* Byte 0 = CMD */
209 buf[1] = *msb; /* Byte 1 = Data MSB */
210 buf[2] = *lsb; /* Byte 2 = Data LSB */
211 buf[3] = buf[4] = buf[5] = 0; /* All other bytes not used */
213 dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
214 buf[0], buf[1], buf[2]);
216 atomic_set (&usb_pcwd->cmd_received, 0);
218 if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
219 HID_REQ_SET_REPORT, HID_DT_REPORT,
220 0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
221 USB_COMMAND_TIMEOUT) != sizeof(buf)) {
222 dbg("usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
224 /* wait till the usb card processed the command,
225 * with a max. timeout of USB_COMMAND_TIMEOUT */
227 for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) {
229 if (atomic_read (&usb_pcwd->cmd_received))
233 if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
234 /* read back response */
235 *msb = usb_pcwd->cmd_data_msb;
236 *lsb = usb_pcwd->cmd_data_lsb;
242 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
244 unsigned char msb = 0x00;
245 unsigned char lsb = 0x00;
248 /* Enable Watchdog */
249 retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb);
251 if ((retval == 0) || (lsb == 0)) {
252 printk(KERN_ERR PFX "Card did not acknowledge enable attempt\n");
259 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
261 unsigned char msb = 0xA5;
262 unsigned char lsb = 0xC3;
265 /* Disable Watchdog */
266 retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb);
268 if ((retval == 0) || (lsb != 0)) {
269 printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
276 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
280 /* Re-trigger Watchdog */
281 usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
286 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
288 unsigned char msb = t / 256;
289 unsigned char lsb = t % 256;
291 if ((t < 0x0001) || (t > 0xFFFF))
294 /* Write new heartbeat to watchdog */
295 usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
301 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature)
303 unsigned char msb, lsb;
305 usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
308 * Convert celsius to fahrenheit, since this was
309 * the decided 'standard' for this return value.
311 *temperature = (lsb * 9 / 5) + 32;
316 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd, int *time_left)
318 unsigned char msb, lsb;
320 /* Read the time that's left before rebooting */
321 /* Note: if the board is not yet armed then we will read 0xFFFF */
322 usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
324 *time_left = (msb << 8) + lsb;
330 * /dev/watchdog handling
333 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
334 size_t len, loff_t *ppos)
336 /* See if we got the magic character 'V' and reload the timer */
341 /* note: just in case someone wrote the magic character
342 * five months ago... */
345 /* scan to see whether or not we got the magic character */
346 for (i = 0; i != len; i++) {
348 if(get_user(c, data+i))
355 /* someone wrote to us, we should reload the timer */
356 usb_pcwd_keepalive(usb_pcwd_device);
361 static int usb_pcwd_ioctl(struct inode *inode, struct file *file,
362 unsigned int cmd, unsigned long arg)
364 void __user *argp = (void __user *)arg;
365 int __user *p = argp;
366 static struct watchdog_info ident = {
367 .options = WDIOF_KEEPALIVEPING |
370 .firmware_version = 1,
371 .identity = DRIVER_NAME,
375 case WDIOC_GETSUPPORT:
376 return copy_to_user(argp, &ident,
377 sizeof (ident)) ? -EFAULT : 0;
379 case WDIOC_GETSTATUS:
380 case WDIOC_GETBOOTSTATUS:
381 return put_user(0, p);
387 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
390 return put_user(temperature, p);
393 case WDIOC_KEEPALIVE:
394 usb_pcwd_keepalive(usb_pcwd_device);
397 case WDIOC_SETOPTIONS:
399 int new_options, retval = -EINVAL;
401 if (get_user (new_options, p))
404 if (new_options & WDIOS_DISABLECARD) {
405 usb_pcwd_stop(usb_pcwd_device);
409 if (new_options & WDIOS_ENABLECARD) {
410 usb_pcwd_start(usb_pcwd_device);
417 case WDIOC_SETTIMEOUT:
421 if (get_user(new_heartbeat, p))
424 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
427 usb_pcwd_keepalive(usb_pcwd_device);
431 case WDIOC_GETTIMEOUT:
432 return put_user(heartbeat, p);
434 case WDIOC_GETTIMELEFT:
438 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
441 return put_user(time_left, p);
449 static int usb_pcwd_open(struct inode *inode, struct file *file)
451 /* /dev/watchdog can only be opened once */
452 if (test_and_set_bit(0, &is_active))
456 usb_pcwd_start(usb_pcwd_device);
457 usb_pcwd_keepalive(usb_pcwd_device);
458 return nonseekable_open(inode, file);
461 static int usb_pcwd_release(struct inode *inode, struct file *file)
464 * Shut off the timer.
466 if (expect_release == 42) {
467 usb_pcwd_stop(usb_pcwd_device);
469 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
470 usb_pcwd_keepalive(usb_pcwd_device);
473 clear_bit(0, &is_active);
478 * /dev/temperature handling
481 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
482 size_t len, loff_t *ppos)
486 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
489 if (copy_to_user(data, &temperature, 1))
495 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
497 return nonseekable_open(inode, file);
500 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
509 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
511 if (code==SYS_DOWN || code==SYS_HALT) {
512 /* Turn the WDT off */
513 usb_pcwd_stop(usb_pcwd_device);
523 static const struct file_operations usb_pcwd_fops = {
524 .owner = THIS_MODULE,
526 .write = usb_pcwd_write,
527 .ioctl = usb_pcwd_ioctl,
528 .open = usb_pcwd_open,
529 .release = usb_pcwd_release,
532 static struct miscdevice usb_pcwd_miscdev = {
533 .minor = WATCHDOG_MINOR,
535 .fops = &usb_pcwd_fops,
538 static const struct file_operations usb_pcwd_temperature_fops = {
539 .owner = THIS_MODULE,
541 .read = usb_pcwd_temperature_read,
542 .open = usb_pcwd_temperature_open,
543 .release = usb_pcwd_temperature_release,
546 static struct miscdevice usb_pcwd_temperature_miscdev = {
548 .name = "temperature",
549 .fops = &usb_pcwd_temperature_fops,
552 static struct notifier_block usb_pcwd_notifier = {
553 .notifier_call = usb_pcwd_notify_sys,
559 static inline void usb_pcwd_delete (struct usb_pcwd_private *usb_pcwd)
561 usb_free_urb(usb_pcwd->intr_urb);
562 if (usb_pcwd->intr_buffer != NULL)
563 usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
564 usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
571 * Called by the usb core when a new device is connected that it thinks
572 * this driver might be interested in.
574 static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
576 struct usb_device *udev = interface_to_usbdev(interface);
577 struct usb_host_interface *iface_desc;
578 struct usb_endpoint_descriptor *endpoint;
579 struct usb_pcwd_private *usb_pcwd = NULL;
581 int retval = -ENOMEM;
583 unsigned char fw_rev_major, fw_rev_minor;
585 unsigned char option_switches, dummy;
588 if (cards_found > 1) {
589 printk(KERN_ERR PFX "This driver only supports 1 device\n");
593 /* get the active interface descriptor */
594 iface_desc = interface->cur_altsetting;
596 /* check out that we have a HID device */
597 if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
598 printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
602 /* check out the endpoint: it has to be Interrupt & IN */
603 endpoint = &iface_desc->endpoint[0].desc;
605 if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
606 ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
607 == USB_ENDPOINT_XFER_INT))) {
608 /* we didn't find a Interrupt endpoint with direction IN */
609 printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
613 /* get a handle to the interrupt data pipe */
614 pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
615 maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
617 /* allocate memory for our device and initialize it */
618 usb_pcwd = kmalloc (sizeof(struct usb_pcwd_private), GFP_KERNEL);
619 if (usb_pcwd == NULL) {
620 printk(KERN_ERR PFX "Out of memory\n");
623 memset (usb_pcwd, 0x00, sizeof (*usb_pcwd));
625 usb_pcwd_device = usb_pcwd;
627 init_MUTEX (&usb_pcwd->sem);
628 usb_pcwd->udev = udev;
629 usb_pcwd->interface = interface;
630 usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
631 usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);
633 /* set up the memory buffer's */
634 if (!(usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, GFP_ATOMIC, &usb_pcwd->intr_dma))) {
635 printk(KERN_ERR PFX "Out of memory\n");
639 /* allocate the urb's */
640 usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
641 if (!usb_pcwd->intr_urb) {
642 printk(KERN_ERR PFX "Out of memory\n");
646 /* initialise the intr urb's */
647 usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
648 usb_pcwd->intr_buffer, usb_pcwd->intr_size,
649 usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
650 usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
651 usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
653 /* register our interrupt URB with the USB system */
654 if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
655 printk(KERN_ERR PFX "Problem registering interrupt URB\n");
656 retval = -EIO; /* failure */
660 /* The device exists and can be communicated with */
661 usb_pcwd->exists = 1;
664 usb_pcwd_stop(usb_pcwd);
666 /* Get the Firmware Version */
667 got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
669 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
671 sprintf(fw_ver_str, "<card no answer>");
674 printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
677 /* Get switch settings */
678 usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);
680 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
682 ((option_switches & 0x10) ? "ON" : "OFF"),
683 ((option_switches & 0x08) ? "ON" : "OFF"));
685 /* Check that the heartbeat value is within it's range ; if not reset to the default */
686 if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
687 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
688 printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
692 retval = register_reboot_notifier(&usb_pcwd_notifier);
694 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
699 retval = misc_register(&usb_pcwd_temperature_miscdev);
701 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
703 goto err_out_unregister_reboot;
706 retval = misc_register(&usb_pcwd_miscdev);
708 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
709 WATCHDOG_MINOR, retval);
710 goto err_out_misc_deregister;
713 /* we can register the device now, as it is ready */
714 usb_set_intfdata (interface, usb_pcwd);
716 printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
717 heartbeat, nowayout);
721 err_out_misc_deregister:
722 misc_deregister(&usb_pcwd_temperature_miscdev);
723 err_out_unregister_reboot:
724 unregister_reboot_notifier(&usb_pcwd_notifier);
727 usb_pcwd_delete(usb_pcwd);
728 usb_pcwd_device = NULL;
734 * usb_pcwd_disconnect
736 * Called by the usb core when the device is removed from the system.
738 * This routine guarantees that the driver will not submit any more urbs
739 * by clearing dev->udev.
741 static void usb_pcwd_disconnect(struct usb_interface *interface)
743 struct usb_pcwd_private *usb_pcwd;
745 /* prevent races with open() */
746 mutex_lock(&disconnect_mutex);
748 usb_pcwd = usb_get_intfdata (interface);
749 usb_set_intfdata (interface, NULL);
751 down (&usb_pcwd->sem);
753 /* Stop the timer before we leave */
755 usb_pcwd_stop(usb_pcwd);
757 /* We should now stop communicating with the USB PCWD device */
758 usb_pcwd->exists = 0;
761 misc_deregister(&usb_pcwd_miscdev);
762 misc_deregister(&usb_pcwd_temperature_miscdev);
763 unregister_reboot_notifier(&usb_pcwd_notifier);
767 /* Delete the USB PCWD device */
768 usb_pcwd_delete(usb_pcwd);
772 mutex_unlock(&disconnect_mutex);
774 printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
782 static int __init usb_pcwd_init(void)
786 /* register this driver with the USB subsystem */
787 result = usb_register(&usb_pcwd_driver);
789 printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
794 printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
802 static void __exit usb_pcwd_exit(void)
804 /* deregister this driver with the USB subsystem */
805 usb_deregister(&usb_pcwd_driver);
809 module_init (usb_pcwd_init);
810 module_exit (usb_pcwd_exit);