1 // SPDX-License-Identifier: GPL-2.0+
3 * Berkshire USB-PC Watchdog Card Driver
5 * (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
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>
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.
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/
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/... */
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"
50 MODULE_AUTHOR(DRIVER_AUTHOR
);
51 MODULE_DESCRIPTION(DRIVER_DESC
);
52 MODULE_LICENSE("GPL");
54 #define WATCHDOG_HEARTBEAT 0 /* default heartbeat =
55 delay-time from dip-switches */
56 static int heartbeat
= WATCHDOG_HEARTBEAT
;
57 module_param(heartbeat
, int, 0);
58 MODULE_PARM_DESC(heartbeat
, "Watchdog heartbeat in seconds. "
59 "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
60 __MODULE_STRING(WATCHDOG_HEARTBEAT
) ")");
62 static bool nowayout
= WATCHDOG_NOWAYOUT
;
63 module_param(nowayout
, bool, 0);
64 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started (default="
65 __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
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
71 /* table of devices that work with this driver */
72 static const struct usb_device_id usb_pcwd_table
[] = {
73 { USB_DEVICE(USB_PCWD_VENDOR_ID
, USB_PCWD_PRODUCT_ID
) },
74 { } /* Terminating entry */
76 MODULE_DEVICE_TABLE(usb
, usb_pcwd_table
);
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
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
94 /* Watchdog's Dip Switch heartbeat values */
95 static 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 */
106 /* We can only use 1 card due to the /dev/watchdog restriction */
107 static int cards_found
;
109 /* some internal variables */
110 static unsigned long is_active
;
111 static char expect_release
;
113 /* Structure to hold all of our device specific stuff */
114 struct 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
;
120 /* the interface number used for cmd's */
121 unsigned int interface_number
;
123 /* the buffer to intr data */
124 unsigned char *intr_buffer
;
125 /* the dma address for the intr buffer */
127 /* the size of the intr buffer */
129 /* the urb used for the intr pipe */
130 struct urb
*intr_urb
;
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
;
141 /* Wether or not the device exists */
143 /* locks this structure */
146 static struct usb_pcwd_private
*usb_pcwd_device
;
148 /* prevent races between open() and disconnect() */
149 static DEFINE_MUTEX(disconnect_mutex
);
151 /* local function prototypes */
152 static int usb_pcwd_probe(struct usb_interface
*interface
,
153 const struct usb_device_id
*id
);
154 static void usb_pcwd_disconnect(struct usb_interface
*interface
);
156 /* usb specific object needed to register this driver with the usb subsystem */
157 static struct usb_driver usb_pcwd_driver
= {
159 .probe
= usb_pcwd_probe
,
160 .disconnect
= usb_pcwd_disconnect
,
161 .id_table
= usb_pcwd_table
,
165 static void usb_pcwd_intr_done(struct urb
*urb
)
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
;
173 switch (urb
->status
) {
174 case 0: /* success */
176 case -ECONNRESET
: /* unlink */
179 /* this urb is terminated, clean up */
180 dev_dbg(dev
, "%s - urb shutting down with status: %d",
181 __func__
, urb
->status
);
183 /* -EPIPE: should clear the halt */
185 dev_dbg(dev
, "%s - nonzero urb status received: %d",
186 __func__
, urb
->status
);
190 dev_dbg(dev
, "received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
191 data
[0], data
[1], data
[2]);
193 usb_pcwd
->cmd_command
= data
[0];
194 usb_pcwd
->cmd_data_msb
= data
[1];
195 usb_pcwd
->cmd_data_lsb
= data
[2];
197 /* notify anyone waiting that the cmd has finished */
198 atomic_set(&usb_pcwd
->cmd_received
, 1);
201 retval
= usb_submit_urb(urb
, GFP_ATOMIC
);
203 pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n",
207 static int usb_pcwd_send_command(struct usb_pcwd_private
*usb_pcwd
,
208 unsigned char cmd
, unsigned char *msb
, unsigned char *lsb
)
210 int got_response
, count
;
213 /* We will not send any commands if the USB PCWD device does
215 if ((!usb_pcwd
) || (!usb_pcwd
->exists
))
218 buf
= kmalloc(6, GFP_KERNEL
);
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 */
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]);
233 atomic_set(&usb_pcwd
->cmd_received
, 0);
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",
243 /* wait till the usb card processed the command,
244 * with a max. timeout of USB_COMMAND_TIMEOUT */
246 for (count
= 0; (count
< USB_COMMAND_TIMEOUT
) && (!got_response
);
249 if (atomic_read(&usb_pcwd
->cmd_received
))
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
;
264 static int usb_pcwd_start(struct usb_pcwd_private
*usb_pcwd
)
266 unsigned char msb
= 0x00;
267 unsigned char lsb
= 0x00;
270 /* Enable Watchdog */
271 retval
= usb_pcwd_send_command(usb_pcwd
, CMD_ENABLE_WATCHDOG
,
274 if ((retval
== 0) || (lsb
== 0)) {
275 pr_err("Card did not acknowledge enable attempt\n");
282 static int usb_pcwd_stop(struct usb_pcwd_private
*usb_pcwd
)
284 unsigned char msb
= 0xA5;
285 unsigned char lsb
= 0xC3;
288 /* Disable Watchdog */
289 retval
= usb_pcwd_send_command(usb_pcwd
, CMD_DISABLE_WATCHDOG
,
292 if ((retval
== 0) || (lsb
!= 0)) {
293 pr_err("Card did not acknowledge disable attempt\n");
300 static int usb_pcwd_keepalive(struct usb_pcwd_private
*usb_pcwd
)
304 /* Re-trigger Watchdog */
305 usb_pcwd_send_command(usb_pcwd
, CMD_TRIGGER
, &dummy
, &dummy
);
310 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private
*usb_pcwd
, int t
)
312 unsigned char msb
= t
/ 256;
313 unsigned char lsb
= t
% 256;
315 if ((t
< 0x0001) || (t
> 0xFFFF))
318 /* Write new heartbeat to watchdog */
319 usb_pcwd_send_command(usb_pcwd
, CMD_WRITE_WATCHDOG_TIMEOUT
, &msb
, &lsb
);
325 static int usb_pcwd_get_temperature(struct usb_pcwd_private
*usb_pcwd
,
328 unsigned char msb
, lsb
;
330 usb_pcwd_send_command(usb_pcwd
, CMD_READ_TEMP
, &msb
, &lsb
);
333 * Convert celsius to fahrenheit, since this was
334 * the decided 'standard' for this return value.
336 *temperature
= (lsb
* 9 / 5) + 32;
341 static int usb_pcwd_get_timeleft(struct usb_pcwd_private
*usb_pcwd
,
344 unsigned char msb
, lsb
;
346 /* Read the time that's left before rebooting */
347 /* Note: if the board is not yet armed then we will read 0xFFFF */
348 usb_pcwd_send_command(usb_pcwd
, CMD_READ_WATCHDOG_TIMEOUT
, &msb
, &lsb
);
350 *time_left
= (msb
<< 8) + lsb
;
356 * /dev/watchdog handling
359 static ssize_t
usb_pcwd_write(struct file
*file
, const char __user
*data
,
360 size_t len
, loff_t
*ppos
)
362 /* See if we got the magic character 'V' and reload the timer */
367 /* note: just in case someone wrote the magic character
368 * five months ago... */
371 /* scan to see whether or not we got the
373 for (i
= 0; i
!= len
; i
++) {
375 if (get_user(c
, data
+ i
))
382 /* someone wrote to us, we should reload the timer */
383 usb_pcwd_keepalive(usb_pcwd_device
);
388 static long usb_pcwd_ioctl(struct file
*file
, unsigned int cmd
,
391 void __user
*argp
= (void __user
*)arg
;
392 int __user
*p
= argp
;
393 static const struct watchdog_info ident
= {
394 .options
= WDIOF_KEEPALIVEPING
|
397 .firmware_version
= 1,
398 .identity
= DRIVER_NAME
,
402 case WDIOC_GETSUPPORT
:
403 return copy_to_user(argp
, &ident
, sizeof(ident
)) ? -EFAULT
: 0;
405 case WDIOC_GETSTATUS
:
406 case WDIOC_GETBOOTSTATUS
:
407 return put_user(0, p
);
413 if (usb_pcwd_get_temperature(usb_pcwd_device
, &temperature
))
416 return put_user(temperature
, p
);
419 case WDIOC_SETOPTIONS
:
421 int new_options
, retval
= -EINVAL
;
423 if (get_user(new_options
, p
))
426 if (new_options
& WDIOS_DISABLECARD
) {
427 usb_pcwd_stop(usb_pcwd_device
);
431 if (new_options
& WDIOS_ENABLECARD
) {
432 usb_pcwd_start(usb_pcwd_device
);
439 case WDIOC_KEEPALIVE
:
440 usb_pcwd_keepalive(usb_pcwd_device
);
443 case WDIOC_SETTIMEOUT
:
447 if (get_user(new_heartbeat
, p
))
450 if (usb_pcwd_set_heartbeat(usb_pcwd_device
, new_heartbeat
))
453 usb_pcwd_keepalive(usb_pcwd_device
);
457 case WDIOC_GETTIMEOUT
:
458 return put_user(heartbeat
, p
);
460 case WDIOC_GETTIMELEFT
:
464 if (usb_pcwd_get_timeleft(usb_pcwd_device
, &time_left
))
467 return put_user(time_left
, p
);
475 static int usb_pcwd_open(struct inode
*inode
, struct file
*file
)
477 /* /dev/watchdog can only be opened once */
478 if (test_and_set_bit(0, &is_active
))
482 usb_pcwd_start(usb_pcwd_device
);
483 usb_pcwd_keepalive(usb_pcwd_device
);
484 return stream_open(inode
, file
);
487 static int usb_pcwd_release(struct inode
*inode
, struct file
*file
)
490 * Shut off the timer.
492 if (expect_release
== 42) {
493 usb_pcwd_stop(usb_pcwd_device
);
495 pr_crit("Unexpected close, not stopping watchdog!\n");
496 usb_pcwd_keepalive(usb_pcwd_device
);
499 clear_bit(0, &is_active
);
504 * /dev/temperature handling
507 static ssize_t
usb_pcwd_temperature_read(struct file
*file
, char __user
*data
,
508 size_t len
, loff_t
*ppos
)
512 if (usb_pcwd_get_temperature(usb_pcwd_device
, &temperature
))
515 if (copy_to_user(data
, &temperature
, 1))
521 static int usb_pcwd_temperature_open(struct inode
*inode
, struct file
*file
)
523 return stream_open(inode
, file
);
526 static int usb_pcwd_temperature_release(struct inode
*inode
, struct file
*file
)
535 static int usb_pcwd_notify_sys(struct notifier_block
*this, unsigned long code
,
538 if (code
== SYS_DOWN
|| code
== SYS_HALT
)
539 usb_pcwd_stop(usb_pcwd_device
); /* Turn the WDT off */
548 static const struct file_operations usb_pcwd_fops
= {
549 .owner
= THIS_MODULE
,
551 .write
= usb_pcwd_write
,
552 .unlocked_ioctl
= usb_pcwd_ioctl
,
553 .compat_ioctl
= compat_ptr_ioctl
,
554 .open
= usb_pcwd_open
,
555 .release
= usb_pcwd_release
,
558 static struct miscdevice usb_pcwd_miscdev
= {
559 .minor
= WATCHDOG_MINOR
,
561 .fops
= &usb_pcwd_fops
,
564 static const struct file_operations usb_pcwd_temperature_fops
= {
565 .owner
= THIS_MODULE
,
567 .read
= usb_pcwd_temperature_read
,
568 .open
= usb_pcwd_temperature_open
,
569 .release
= usb_pcwd_temperature_release
,
572 static struct miscdevice usb_pcwd_temperature_miscdev
= {
574 .name
= "temperature",
575 .fops
= &usb_pcwd_temperature_fops
,
578 static struct notifier_block usb_pcwd_notifier
= {
579 .notifier_call
= usb_pcwd_notify_sys
,
585 static inline void usb_pcwd_delete(struct usb_pcwd_private
*usb_pcwd
)
587 usb_free_urb(usb_pcwd
->intr_urb
);
588 usb_free_coherent(usb_pcwd
->udev
, usb_pcwd
->intr_size
,
589 usb_pcwd
->intr_buffer
, usb_pcwd
->intr_dma
);
596 * Called by the usb core when a new device is connected that it thinks
597 * this driver might be interested in.
599 static int usb_pcwd_probe(struct usb_interface
*interface
,
600 const struct usb_device_id
*id
)
602 struct usb_device
*udev
= interface_to_usbdev(interface
);
603 struct usb_host_interface
*iface_desc
;
604 struct usb_endpoint_descriptor
*endpoint
;
605 struct usb_pcwd_private
*usb_pcwd
= NULL
;
607 int retval
= -ENOMEM
;
609 unsigned char fw_rev_major
, fw_rev_minor
;
611 unsigned char option_switches
, dummy
;
614 if (cards_found
> 1) {
615 pr_err("This driver only supports 1 device\n");
619 /* get the active interface descriptor */
620 iface_desc
= interface
->cur_altsetting
;
622 /* check out that we have a HID device */
623 if (!(iface_desc
->desc
.bInterfaceClass
== USB_CLASS_HID
)) {
624 pr_err("The device isn't a Human Interface Device\n");
628 if (iface_desc
->desc
.bNumEndpoints
< 1)
631 /* check out the endpoint: it has to be Interrupt & IN */
632 endpoint
= &iface_desc
->endpoint
[0].desc
;
634 if (!usb_endpoint_is_int_in(endpoint
)) {
635 /* we didn't find a Interrupt endpoint with direction IN */
636 pr_err("Couldn't find an INTR & IN endpoint\n");
640 /* get a handle to the interrupt data pipe */
641 pipe
= usb_rcvintpipe(udev
, endpoint
->bEndpointAddress
);
643 /* allocate memory for our device and initialize it */
644 usb_pcwd
= kzalloc(sizeof(struct usb_pcwd_private
), GFP_KERNEL
);
645 if (usb_pcwd
== NULL
)
648 usb_pcwd_device
= usb_pcwd
;
650 mutex_init(&usb_pcwd
->mtx
);
651 usb_pcwd
->udev
= udev
;
652 usb_pcwd
->interface
= interface
;
653 usb_pcwd
->interface_number
= iface_desc
->desc
.bInterfaceNumber
;
654 usb_pcwd
->intr_size
= (le16_to_cpu(endpoint
->wMaxPacketSize
) > 8 ?
655 le16_to_cpu(endpoint
->wMaxPacketSize
) : 8);
657 /* set up the memory buffer's */
658 usb_pcwd
->intr_buffer
= usb_alloc_coherent(udev
, usb_pcwd
->intr_size
,
659 GFP_KERNEL
, &usb_pcwd
->intr_dma
);
660 if (!usb_pcwd
->intr_buffer
) {
661 pr_err("Out of memory\n");
665 /* allocate the urb's */
666 usb_pcwd
->intr_urb
= usb_alloc_urb(0, GFP_KERNEL
);
667 if (!usb_pcwd
->intr_urb
)
670 /* initialise the intr urb's */
671 usb_fill_int_urb(usb_pcwd
->intr_urb
, udev
, pipe
,
672 usb_pcwd
->intr_buffer
, usb_pcwd
->intr_size
,
673 usb_pcwd_intr_done
, usb_pcwd
, endpoint
->bInterval
);
674 usb_pcwd
->intr_urb
->transfer_dma
= usb_pcwd
->intr_dma
;
675 usb_pcwd
->intr_urb
->transfer_flags
|= URB_NO_TRANSFER_DMA_MAP
;
677 /* register our interrupt URB with the USB system */
678 if (usb_submit_urb(usb_pcwd
->intr_urb
, GFP_KERNEL
)) {
679 pr_err("Problem registering interrupt URB\n");
680 retval
= -EIO
; /* failure */
684 /* The device exists and can be communicated with */
685 usb_pcwd
->exists
= 1;
688 usb_pcwd_stop(usb_pcwd
);
690 /* Get the Firmware Version */
691 got_fw_rev
= usb_pcwd_send_command(usb_pcwd
, CMD_GET_FIRMWARE_VERSION
,
692 &fw_rev_major
, &fw_rev_minor
);
694 sprintf(fw_ver_str
, "%u.%02u", fw_rev_major
, fw_rev_minor
);
696 sprintf(fw_ver_str
, "<card no answer>");
698 pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str
);
700 /* Get switch settings */
701 usb_pcwd_send_command(usb_pcwd
, CMD_GET_DIP_SWITCH_SETTINGS
, &dummy
,
704 pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
706 ((option_switches
& 0x10) ? "ON" : "OFF"),
707 ((option_switches
& 0x08) ? "ON" : "OFF"));
709 /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
711 heartbeat
= heartbeat_tbl
[(option_switches
& 0x07)];
713 /* Check that the heartbeat value is within it's range ;
714 * if not reset to the default */
715 if (usb_pcwd_set_heartbeat(usb_pcwd
, heartbeat
)) {
716 usb_pcwd_set_heartbeat(usb_pcwd
, WATCHDOG_HEARTBEAT
);
717 pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
721 retval
= register_reboot_notifier(&usb_pcwd_notifier
);
723 pr_err("cannot register reboot notifier (err=%d)\n", retval
);
727 retval
= misc_register(&usb_pcwd_temperature_miscdev
);
729 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
731 goto err_out_unregister_reboot
;
734 retval
= misc_register(&usb_pcwd_miscdev
);
736 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
737 WATCHDOG_MINOR
, retval
);
738 goto err_out_misc_deregister
;
741 /* we can register the device now, as it is ready */
742 usb_set_intfdata(interface
, usb_pcwd
);
744 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
745 heartbeat
, nowayout
);
749 err_out_misc_deregister
:
750 misc_deregister(&usb_pcwd_temperature_miscdev
);
751 err_out_unregister_reboot
:
752 unregister_reboot_notifier(&usb_pcwd_notifier
);
755 usb_pcwd_delete(usb_pcwd
);
756 usb_pcwd_device
= NULL
;
762 * usb_pcwd_disconnect
764 * Called by the usb core when the device is removed from the system.
766 * This routine guarantees that the driver will not submit any more urbs
767 * by clearing dev->udev.
769 static void usb_pcwd_disconnect(struct usb_interface
*interface
)
771 struct usb_pcwd_private
*usb_pcwd
;
773 /* prevent races with open() */
774 mutex_lock(&disconnect_mutex
);
776 usb_pcwd
= usb_get_intfdata(interface
);
777 usb_set_intfdata(interface
, NULL
);
779 mutex_lock(&usb_pcwd
->mtx
);
781 /* Stop the timer before we leave */
783 usb_pcwd_stop(usb_pcwd
);
785 /* We should now stop communicating with the USB PCWD device */
786 usb_pcwd
->exists
= 0;
789 misc_deregister(&usb_pcwd_miscdev
);
790 misc_deregister(&usb_pcwd_temperature_miscdev
);
791 unregister_reboot_notifier(&usb_pcwd_notifier
);
793 mutex_unlock(&usb_pcwd
->mtx
);
795 /* Delete the USB PCWD device */
796 usb_pcwd_delete(usb_pcwd
);
800 mutex_unlock(&disconnect_mutex
);
802 pr_info("USB PC Watchdog disconnected\n");
805 module_usb_driver(usb_pcwd_driver
);