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/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 */
44 #include <asm/uaccess.h> /* For copy_to_user/put_user/... */
47 #ifdef CONFIG_USB_DEBUG
53 /* Use our own dbg macro */
55 #define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
58 /* Module and Version Information */
59 #define DRIVER_VERSION "1.01"
60 #define DRIVER_DATE "15 Mar 2005"
61 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
62 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
63 #define DRIVER_LICENSE "GPL"
64 #define DRIVER_NAME "pcwd_usb"
65 #define PFX DRIVER_NAME ": "
67 MODULE_AUTHOR(DRIVER_AUTHOR);
68 MODULE_DESCRIPTION(DRIVER_DESC);
69 MODULE_LICENSE(DRIVER_LICENSE);
70 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
71 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
73 /* Module Parameters */
74 module_param(debug, int, 0);
75 MODULE_PARM_DESC(debug, "Debug enabled or not");
77 #define WATCHDOG_HEARTBEAT 2 /* 2 sec default heartbeat */
78 static int heartbeat = WATCHDOG_HEARTBEAT;
79 module_param(heartbeat, int, 0);
80 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
82 static int nowayout = WATCHDOG_NOWAYOUT;
83 module_param(nowayout, int, 0);
84 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
86 /* The vendor and product id's for the USB-PC Watchdog card */
87 #define USB_PCWD_VENDOR_ID 0x0c98
88 #define USB_PCWD_PRODUCT_ID 0x1140
90 /* table of devices that work with this driver */
91 static struct usb_device_id usb_pcwd_table [] = {
92 { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
93 { } /* Terminating entry */
95 MODULE_DEVICE_TABLE (usb, usb_pcwd_table);
97 /* according to documentation max. time to process a command for the USB
98 * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
99 #define USB_COMMAND_TIMEOUT 250
101 /* Watchdog's internal commands */
102 #define CMD_READ_TEMP 0x02 /* Read Temperature; Re-trigger Watchdog */
103 #define CMD_TRIGGER CMD_READ_TEMP
104 #define CMD_GET_STATUS 0x04 /* Get Status Information */
105 #define CMD_GET_FIRMWARE_VERSION 0x08 /* Get Firmware Version */
106 #define CMD_GET_DIP_SWITCH_SETTINGS 0x0c /* Get Dip Switch Settings */
107 #define CMD_READ_WATCHDOG_TIMEOUT 0x18 /* Read Current Watchdog Time */
108 #define CMD_WRITE_WATCHDOG_TIMEOUT 0x19 /* Write Current Watchdog Time */
109 #define CMD_ENABLE_WATCHDOG 0x30 /* Enable / Disable Watchdog */
110 #define CMD_DISABLE_WATCHDOG CMD_ENABLE_WATCHDOG
112 /* We can only use 1 card due to the /dev/watchdog restriction */
113 static int cards_found;
115 /* some internal variables */
116 static unsigned long is_active;
117 static char expect_release;
119 /* Structure to hold all of our device specific stuff */
120 struct usb_pcwd_private {
121 struct usb_device * udev; /* save off the usb device pointer */
122 struct usb_interface * interface; /* the interface for this device */
124 unsigned int interface_number; /* the interface number used for cmd's */
126 unsigned char * intr_buffer; /* the buffer to intr data */
127 dma_addr_t intr_dma; /* the dma address for the intr buffer */
128 size_t intr_size; /* the size of the intr buffer */
129 struct urb * intr_urb; /* the urb used for the intr pipe */
131 unsigned char cmd_command; /* The command that is reported back */
132 unsigned char cmd_data_msb; /* The data MSB that is reported back */
133 unsigned char cmd_data_lsb; /* The data LSB that is reported back */
134 atomic_t cmd_received; /* true if we received a report after a command */
136 int exists; /* Wether or not the device exists */
137 struct semaphore sem; /* locks this structure */
139 static struct usb_pcwd_private *usb_pcwd_device;
141 /* prevent races between open() and disconnect() */
142 static DEFINE_MUTEX(disconnect_mutex);
144 /* local function prototypes */
145 static int usb_pcwd_probe (struct usb_interface *interface, const struct usb_device_id *id);
146 static void usb_pcwd_disconnect (struct usb_interface *interface);
148 /* usb specific object needed to register this driver with the usb subsystem */
149 static struct usb_driver usb_pcwd_driver = {
151 .probe = usb_pcwd_probe,
152 .disconnect = usb_pcwd_disconnect,
153 .id_table = usb_pcwd_table,
157 static void usb_pcwd_intr_done(struct urb *urb)
159 struct usb_pcwd_private *usb_pcwd = (struct usb_pcwd_private *)urb->context;
160 unsigned char *data = usb_pcwd->intr_buffer;
163 switch (urb->status) {
164 case 0: /* success */
166 case -ECONNRESET: /* unlink */
169 /* this urb is terminated, clean up */
170 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
172 /* -EPIPE: should clear the halt */
174 dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
178 dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
179 data[0], data[1], data[2]);
181 usb_pcwd->cmd_command = data[0];
182 usb_pcwd->cmd_data_msb = data[1];
183 usb_pcwd->cmd_data_lsb = data[2];
185 /* notify anyone waiting that the cmd has finished */
186 atomic_set (&usb_pcwd->cmd_received, 1);
189 retval = usb_submit_urb (urb, GFP_ATOMIC);
191 printk(KERN_ERR PFX "can't resubmit intr, usb_submit_urb failed with result %d\n",
195 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd,
196 unsigned char *msb, unsigned char *lsb)
198 int got_response, count;
199 unsigned char buf[6];
201 /* We will not send any commands if the USB PCWD device does not exist */
202 if ((!usb_pcwd) || (!usb_pcwd->exists))
205 /* The USB PC Watchdog uses a 6 byte report format. The board currently uses
206 * only 3 of the six bytes of the report. */
207 buf[0] = cmd; /* Byte 0 = CMD */
208 buf[1] = *msb; /* Byte 1 = Data MSB */
209 buf[2] = *lsb; /* Byte 2 = Data LSB */
210 buf[3] = buf[4] = buf[5] = 0; /* All other bytes not used */
212 dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
213 buf[0], buf[1], buf[2]);
215 atomic_set (&usb_pcwd->cmd_received, 0);
217 if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
218 HID_REQ_SET_REPORT, HID_DT_REPORT,
219 0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
220 USB_COMMAND_TIMEOUT) != sizeof(buf)) {
221 dbg("usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
223 /* wait till the usb card processed the command,
224 * with a max. timeout of USB_COMMAND_TIMEOUT */
226 for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) {
228 if (atomic_read (&usb_pcwd->cmd_received))
232 if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
233 /* read back response */
234 *msb = usb_pcwd->cmd_data_msb;
235 *lsb = usb_pcwd->cmd_data_lsb;
241 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
243 unsigned char msb = 0x00;
244 unsigned char lsb = 0x00;
247 /* Enable Watchdog */
248 retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb);
250 if ((retval == 0) || (lsb == 0)) {
251 printk(KERN_ERR PFX "Card did not acknowledge enable attempt\n");
258 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
260 unsigned char msb = 0xA5;
261 unsigned char lsb = 0xC3;
264 /* Disable Watchdog */
265 retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb);
267 if ((retval == 0) || (lsb != 0)) {
268 printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
275 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
279 /* Re-trigger Watchdog */
280 usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
285 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
287 unsigned char msb = t / 256;
288 unsigned char lsb = t % 256;
290 if ((t < 0x0001) || (t > 0xFFFF))
293 /* Write new heartbeat to watchdog */
294 usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
300 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature)
302 unsigned char msb, lsb;
304 usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
307 * Convert celsius to fahrenheit, since this was
308 * the decided 'standard' for this return value.
310 *temperature = (lsb * 9 / 5) + 32;
315 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd, int *time_left)
317 unsigned char msb, lsb;
319 /* Read the time that's left before rebooting */
320 /* Note: if the board is not yet armed then we will read 0xFFFF */
321 usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
323 *time_left = (msb << 8) + lsb;
329 * /dev/watchdog handling
332 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
333 size_t len, loff_t *ppos)
335 /* See if we got the magic character 'V' and reload the timer */
340 /* note: just in case someone wrote the magic character
341 * five months ago... */
344 /* scan to see whether or not we got the magic character */
345 for (i = 0; i != len; i++) {
347 if(get_user(c, data+i))
354 /* someone wrote to us, we should reload the timer */
355 usb_pcwd_keepalive(usb_pcwd_device);
360 static int usb_pcwd_ioctl(struct inode *inode, struct file *file,
361 unsigned int cmd, unsigned long arg)
363 void __user *argp = (void __user *)arg;
364 int __user *p = argp;
365 static struct watchdog_info ident = {
366 .options = WDIOF_KEEPALIVEPING |
369 .firmware_version = 1,
370 .identity = DRIVER_NAME,
374 case WDIOC_GETSUPPORT:
375 return copy_to_user(argp, &ident,
376 sizeof (ident)) ? -EFAULT : 0;
378 case WDIOC_GETSTATUS:
379 case WDIOC_GETBOOTSTATUS:
380 return put_user(0, p);
386 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
389 return put_user(temperature, p);
392 case WDIOC_KEEPALIVE:
393 usb_pcwd_keepalive(usb_pcwd_device);
396 case WDIOC_SETOPTIONS:
398 int new_options, retval = -EINVAL;
400 if (get_user (new_options, p))
403 if (new_options & WDIOS_DISABLECARD) {
404 usb_pcwd_stop(usb_pcwd_device);
408 if (new_options & WDIOS_ENABLECARD) {
409 usb_pcwd_start(usb_pcwd_device);
416 case WDIOC_SETTIMEOUT:
420 if (get_user(new_heartbeat, p))
423 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
426 usb_pcwd_keepalive(usb_pcwd_device);
430 case WDIOC_GETTIMEOUT:
431 return put_user(heartbeat, p);
433 case WDIOC_GETTIMELEFT:
437 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
440 return put_user(time_left, p);
448 static int usb_pcwd_open(struct inode *inode, struct file *file)
450 /* /dev/watchdog can only be opened once */
451 if (test_and_set_bit(0, &is_active))
455 usb_pcwd_start(usb_pcwd_device);
456 usb_pcwd_keepalive(usb_pcwd_device);
457 return nonseekable_open(inode, file);
460 static int usb_pcwd_release(struct inode *inode, struct file *file)
463 * Shut off the timer.
465 if (expect_release == 42) {
466 usb_pcwd_stop(usb_pcwd_device);
468 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
469 usb_pcwd_keepalive(usb_pcwd_device);
472 clear_bit(0, &is_active);
477 * /dev/temperature handling
480 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
481 size_t len, loff_t *ppos)
485 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
488 if (copy_to_user(data, &temperature, 1))
494 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
496 return nonseekable_open(inode, file);
499 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
508 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
510 if (code==SYS_DOWN || code==SYS_HALT) {
511 /* Turn the WDT off */
512 usb_pcwd_stop(usb_pcwd_device);
522 static const struct file_operations usb_pcwd_fops = {
523 .owner = THIS_MODULE,
525 .write = usb_pcwd_write,
526 .ioctl = usb_pcwd_ioctl,
527 .open = usb_pcwd_open,
528 .release = usb_pcwd_release,
531 static struct miscdevice usb_pcwd_miscdev = {
532 .minor = WATCHDOG_MINOR,
534 .fops = &usb_pcwd_fops,
537 static const struct file_operations usb_pcwd_temperature_fops = {
538 .owner = THIS_MODULE,
540 .read = usb_pcwd_temperature_read,
541 .open = usb_pcwd_temperature_open,
542 .release = usb_pcwd_temperature_release,
545 static struct miscdevice usb_pcwd_temperature_miscdev = {
547 .name = "temperature",
548 .fops = &usb_pcwd_temperature_fops,
551 static struct notifier_block usb_pcwd_notifier = {
552 .notifier_call = usb_pcwd_notify_sys,
558 static inline void usb_pcwd_delete (struct usb_pcwd_private *usb_pcwd)
560 usb_free_urb(usb_pcwd->intr_urb);
561 if (usb_pcwd->intr_buffer != NULL)
562 usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
563 usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
570 * Called by the usb core when a new device is connected that it thinks
571 * this driver might be interested in.
573 static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
575 struct usb_device *udev = interface_to_usbdev(interface);
576 struct usb_host_interface *iface_desc;
577 struct usb_endpoint_descriptor *endpoint;
578 struct usb_pcwd_private *usb_pcwd = NULL;
580 int retval = -ENOMEM;
582 unsigned char fw_rev_major, fw_rev_minor;
584 unsigned char option_switches, dummy;
587 if (cards_found > 1) {
588 printk(KERN_ERR PFX "This driver only supports 1 device\n");
592 /* get the active interface descriptor */
593 iface_desc = interface->cur_altsetting;
595 /* check out that we have a HID device */
596 if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
597 printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
601 /* check out the endpoint: it has to be Interrupt & IN */
602 endpoint = &iface_desc->endpoint[0].desc;
604 if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
605 ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
606 == USB_ENDPOINT_XFER_INT))) {
607 /* we didn't find a Interrupt endpoint with direction IN */
608 printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
612 /* get a handle to the interrupt data pipe */
613 pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
614 maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
616 /* allocate memory for our device and initialize it */
617 usb_pcwd = kmalloc (sizeof(struct usb_pcwd_private), GFP_KERNEL);
618 if (usb_pcwd == NULL) {
619 printk(KERN_ERR PFX "Out of memory\n");
622 memset (usb_pcwd, 0x00, sizeof (*usb_pcwd));
624 usb_pcwd_device = usb_pcwd;
626 init_MUTEX (&usb_pcwd->sem);
627 usb_pcwd->udev = udev;
628 usb_pcwd->interface = interface;
629 usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
630 usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);
632 /* set up the memory buffer's */
633 if (!(usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, GFP_ATOMIC, &usb_pcwd->intr_dma))) {
634 printk(KERN_ERR PFX "Out of memory\n");
638 /* allocate the urb's */
639 usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
640 if (!usb_pcwd->intr_urb) {
641 printk(KERN_ERR PFX "Out of memory\n");
645 /* initialise the intr urb's */
646 usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
647 usb_pcwd->intr_buffer, usb_pcwd->intr_size,
648 usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
649 usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
650 usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
652 /* register our interrupt URB with the USB system */
653 if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
654 printk(KERN_ERR PFX "Problem registering interrupt URB\n");
655 retval = -EIO; /* failure */
659 /* The device exists and can be communicated with */
660 usb_pcwd->exists = 1;
663 usb_pcwd_stop(usb_pcwd);
665 /* Get the Firmware Version */
666 got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
668 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
670 sprintf(fw_ver_str, "<card no answer>");
673 printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
676 /* Get switch settings */
677 usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);
679 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
681 ((option_switches & 0x10) ? "ON" : "OFF"),
682 ((option_switches & 0x08) ? "ON" : "OFF"));
684 /* Check that the heartbeat value is within it's range ; if not reset to the default */
685 if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
686 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
687 printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
691 retval = register_reboot_notifier(&usb_pcwd_notifier);
693 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
698 retval = misc_register(&usb_pcwd_temperature_miscdev);
700 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
702 goto err_out_unregister_reboot;
705 retval = misc_register(&usb_pcwd_miscdev);
707 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
708 WATCHDOG_MINOR, retval);
709 goto err_out_misc_deregister;
712 /* we can register the device now, as it is ready */
713 usb_set_intfdata (interface, usb_pcwd);
715 printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
716 heartbeat, nowayout);
720 err_out_misc_deregister:
721 misc_deregister(&usb_pcwd_temperature_miscdev);
722 err_out_unregister_reboot:
723 unregister_reboot_notifier(&usb_pcwd_notifier);
726 usb_pcwd_delete(usb_pcwd);
727 usb_pcwd_device = NULL;
733 * usb_pcwd_disconnect
735 * Called by the usb core when the device is removed from the system.
737 * This routine guarantees that the driver will not submit any more urbs
738 * by clearing dev->udev.
740 static void usb_pcwd_disconnect(struct usb_interface *interface)
742 struct usb_pcwd_private *usb_pcwd;
744 /* prevent races with open() */
745 mutex_lock(&disconnect_mutex);
747 usb_pcwd = usb_get_intfdata (interface);
748 usb_set_intfdata (interface, NULL);
750 down (&usb_pcwd->sem);
752 /* Stop the timer before we leave */
754 usb_pcwd_stop(usb_pcwd);
756 /* We should now stop communicating with the USB PCWD device */
757 usb_pcwd->exists = 0;
760 misc_deregister(&usb_pcwd_miscdev);
761 misc_deregister(&usb_pcwd_temperature_miscdev);
762 unregister_reboot_notifier(&usb_pcwd_notifier);
766 /* Delete the USB PCWD device */
767 usb_pcwd_delete(usb_pcwd);
771 mutex_unlock(&disconnect_mutex);
773 printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
781 static int __init usb_pcwd_init(void)
785 /* register this driver with the USB subsystem */
786 result = usb_register(&usb_pcwd_driver);
788 printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
793 printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
801 static void __exit usb_pcwd_exit(void)
803 /* deregister this driver with the USB subsystem */
804 usb_deregister(&usb_pcwd_driver);
808 module_init (usb_pcwd_init);
809 module_exit (usb_pcwd_exit);