/*
* Berkshire USB-PC Watchdog Card Driver
*
* (c) Copyright 2004 Wim Van Sebroeck <wim@iguana.be>.
*
* Based on source code of the following authors:
* Ken Hollis <kenji@bitgate.com>,
* Alan Cox <alan@redhat.com>,
* Matt Domsch <Matt_Domsch@dell.com>,
* Rob Radez <rob@osinvestor.com>,
* Greg Kroah-Hartman <greg@kroah.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
* provide warranty for any of this software. This material is
* provided "AS-IS" and at no charge.
*
* Thanks also to Simon Machell at Berkshire Products Inc. for
* providing the test hardware. More info is available at
* http://www.berkprod.com/ or http://www.pcwatchdog.com/
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/smp_lock.h>
#include <linux/completion.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#ifdef CONFIG_USB_DEBUG
static int debug = 1;
#else
static int debug;
#endif
/* Use our own dbg macro */
#undef dbg
#define dbg(format, arg...) do { if (debug) printk(KERN_DEBUG PFX format "\n" , ## arg); } while (0)
/* Module and Version Information */
#define DRIVER_VERSION "1.01"
#define DRIVER_DATE "15 Mar 2005"
#define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
#define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
#define DRIVER_LICENSE "GPL"
#define DRIVER_NAME "pcwd_usb"
#define PFX DRIVER_NAME ": "
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE(DRIVER_LICENSE);
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS_MISCDEV(TEMP_MINOR);
/* Module Parameters */
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug enabled or not");
#define WATCHDOG_HEARTBEAT 2 /* 2 sec default heartbeat */
static int heartbeat = WATCHDOG_HEARTBEAT;
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
/* The vendor and product id's for the USB-PC Watchdog card */
#define USB_PCWD_VENDOR_ID 0x0c98
#define USB_PCWD_PRODUCT_ID 0x1140
/* table of devices that work with this driver */
static struct usb_device_id usb_pcwd_table [] = {
{ USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, usb_pcwd_table);
/* according to documentation max. time to process a command for the USB
* watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
#define USB_COMMAND_TIMEOUT 250
/* Watchdog's internal commands */
#define CMD_READ_TEMP 0x02 /* Read Temperature; Re-trigger Watchdog */
#define CMD_TRIGGER CMD_READ_TEMP
#define CMD_GET_STATUS 0x04 /* Get Status Information */
#define CMD_GET_FIRMWARE_VERSION 0x08 /* Get Firmware Version */
#define CMD_GET_DIP_SWITCH_SETTINGS 0x0c /* Get Dip Switch Settings */
#define CMD_READ_WATCHDOG_TIMEOUT 0x18 /* Read Current Watchdog Time */
#define CMD_WRITE_WATCHDOG_TIMEOUT 0x19 /* Write Current Watchdog Time */
#define CMD_ENABLE_WATCHDOG 0x30 /* Enable / Disable Watchdog */
#define CMD_DISABLE_WATCHDOG CMD_ENABLE_WATCHDOG
/* Some defines that I like to be somewhere else like include/linux/usb_hid.h */
#define HID_REQ_SET_REPORT 0x09
#define HID_DT_REPORT (USB_TYPE_CLASS | 0x02)
/* We can only use 1 card due to the /dev/watchdog restriction */
static int cards_found;
/* some internal variables */
static unsigned long is_active;
static char expect_release;
/* Structure to hold all of our device specific stuff */
struct usb_pcwd_private {
struct usb_device * udev; /* save off the usb device pointer */
struct usb_interface * interface; /* the interface for this device */
unsigned int interface_number; /* the interface number used for cmd's */
unsigned char * intr_buffer; /* the buffer to intr data */
dma_addr_t intr_dma; /* the dma address for the intr buffer */
size_t intr_size; /* the size of the intr buffer */
struct urb * intr_urb; /* the urb used for the intr pipe */
unsigned char cmd_command; /* The command that is reported back */
unsigned char cmd_data_msb; /* The data MSB that is reported back */
unsigned char cmd_data_lsb; /* The data LSB that is reported back */
atomic_t cmd_received; /* true if we received a report after a command */
int exists; /* Wether or not the device exists */
struct semaphore sem; /* locks this structure */
};
static struct usb_pcwd_private *usb_pcwd_device;
/* prevent races between open() and disconnect() */
static DEFINE_MUTEX(disconnect_mutex);
/* local function prototypes */
static int usb_pcwd_probe (struct usb_interface *interface, const struct usb_device_id *id);
static void usb_pcwd_disconnect (struct usb_interface *interface);
/* usb specific object needed to register this driver with the usb subsystem */
static struct usb_driver usb_pcwd_driver = {
.name = DRIVER_NAME,
.probe = usb_pcwd_probe,
.disconnect = usb_pcwd_disconnect,
.id_table = usb_pcwd_table,
};
static void usb_pcwd_intr_done(struct urb *urb, struct pt_regs *regs)
{
struct usb_pcwd_private *usb_pcwd = (struct usb_pcwd_private *)urb->context;
unsigned char *data = usb_pcwd->intr_buffer;
int retval;
switch (urb->status) {
case 0: /* success */
break;
case -ECONNRESET: /* unlink */
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
return;
/* -EPIPE: should clear the halt */
default: /* error */
dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
goto resubmit;
}
dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
data[0], data[1], data[2]);
usb_pcwd->cmd_command = data[0];
usb_pcwd->cmd_data_msb = data[1];
usb_pcwd->cmd_data_lsb = data[2];
/* notify anyone waiting that the cmd has finished */
atomic_set (&usb_pcwd->cmd_received, 1);
resubmit:
retval = usb_submit_urb (urb, GFP_ATOMIC);
if (retval)
printk(KERN_ERR PFX "can't resubmit intr, usb_submit_urb failed with result %d\n",
retval);
}
static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd,
unsigned char *msb, unsigned char *lsb)
{
int got_response, count;
unsigned char buf[6];
/* We will not send any commands if the USB PCWD device does not exist */
if ((!usb_pcwd) || (!usb_pcwd->exists))
return -1;
/* The USB PC Watchdog uses a 6 byte report format. The board currently uses
* only 3 of the six bytes of the report. */
buf[0] = cmd; /* Byte 0 = CMD */
buf[1] = *msb; /* Byte 1 = Data MSB */
buf[2] = *lsb; /* Byte 2 = Data LSB */
buf[3] = buf[4] = buf[5] = 0; /* All other bytes not used */
dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
buf[0], buf[1], buf[2]);
atomic_set (&usb_pcwd->cmd_received, 0);
if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
HID_REQ_SET_REPORT, HID_DT_REPORT,
0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
USB_COMMAND_TIMEOUT) != sizeof(buf)) {
dbg("usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
}
/* wait till the usb card processed the command,
* with a max. timeout of USB_COMMAND_TIMEOUT */
got_response = 0;
for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) {
mdelay(1);
if (atomic_read (&usb_pcwd->cmd_received))
got_response = 1;
}
if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
/* read back response */
*msb = usb_pcwd->cmd_data_msb;
*lsb = usb_pcwd->cmd_data_lsb;
}
return got_response;
}
static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
{
unsigned char msb = 0x00;
unsigned char lsb = 0x00;
int retval;
/* Enable Watchdog */
retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb);
if ((retval == 0) || (lsb == 0)) {
printk(KERN_ERR PFX "Card did not acknowledge enable attempt\n");
return -1;
}
return 0;
}
static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
{
unsigned char msb = 0xA5;
unsigned char lsb = 0xC3;
int retval;
/* Disable Watchdog */
retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb);
if ((retval == 0) || (lsb != 0)) {
printk(KERN_ERR PFX "Card did not acknowledge disable attempt\n");
return -1;
}
return 0;
}
static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
{
unsigned char dummy;
/* Re-trigger Watchdog */
usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
return 0;
}
static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
{
unsigned char msb = t / 256;
unsigned char lsb = t % 256;
if ((t < 0x0001) || (t > 0xFFFF))
return -EINVAL;
/* Write new heartbeat to watchdog */
usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
heartbeat = t;
return 0;
}
static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature)
{
unsigned char msb, lsb;
usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
/*
* Convert celsius to fahrenheit, since this was
* the decided 'standard' for this return value.
*/
*temperature = (lsb * 9 / 5) + 32;
return 0;
}
static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd, int *time_left)
{
unsigned char msb, lsb;
/* Read the time that's left before rebooting */
/* Note: if the board is not yet armed then we will read 0xFFFF */
usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
*time_left = (msb << 8) + lsb;
return 0;
}
/*
* /dev/watchdog handling
*/
static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* See if we got the magic character 'V' and reload the timer */
if (len) {
if (!nowayout) {
size_t i;
/* note: just in case someone wrote the magic character
* five months ago... */
expect_release = 0;
/* scan to see whether or not we got the magic character */
for (i = 0; i != len; i++) {
char c;
if(get_user(c, data+i))
return -EFAULT;
if (c == 'V')
expect_release = 42;
}
}
/* someone wrote to us, we should reload the timer */
usb_pcwd_keepalive(usb_pcwd_device);
}
return len;
}
static int usb_pcwd_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = DRIVER_NAME,
};
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &ident,
sizeof (ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_GETTEMP:
{
int temperature;
if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
return -EFAULT;
return put_user(temperature, p);
}
case WDIOC_KEEPALIVE:
usb_pcwd_keepalive(usb_pcwd_device);
return 0;
case WDIOC_SETOPTIONS:
{
int new_options, retval = -EINVAL;
if (get_user (new_options, p))
return -EFAULT;
if (new_options & WDIOS_DISABLECARD) {
usb_pcwd_stop(usb_pcwd_device);
retval = 0;
}
if (new_options & WDIOS_ENABLECARD) {
usb_pcwd_start(usb_pcwd_device);
retval = 0;
}
return retval;
}
case WDIOC_SETTIMEOUT:
{
int new_heartbeat;
if (get_user(new_heartbeat, p))
return -EFAULT;
if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
return -EINVAL;
usb_pcwd_keepalive(usb_pcwd_device);
/* Fall */
}
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, p);
case WDIOC_GETTIMELEFT:
{
int time_left;
if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
return -EFAULT;
return put_user(time_left, p);
}
default:
return -ENOIOCTLCMD;
}
}
static int usb_pcwd_open(struct inode *inode, struct file *file)
{
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &is_active))
return -EBUSY;
/* Activate */
usb_pcwd_start(usb_pcwd_device);
usb_pcwd_keepalive(usb_pcwd_device);
return nonseekable_open(inode, file);
}
static int usb_pcwd_release(struct inode *inode, struct file *file)
{
/*
* Shut off the timer.
*/
if (expect_release == 42) {
usb_pcwd_stop(usb_pcwd_device);
} else {
printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
usb_pcwd_keepalive(usb_pcwd_device);
}
expect_release = 0;
clear_bit(0, &is_active);
return 0;
}
/*
* /dev/temperature handling
*/
static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
size_t len, loff_t *ppos)
{
int temperature;
if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
return -EFAULT;
if (copy_to_user(data, &temperature, 1))
return -EFAULT;
return 1;
}
static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
{
return nonseekable_open(inode, file);
}
static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
{
return 0;
}
/*
* Notify system
*/
static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
{
if (code==SYS_DOWN || code==SYS_HALT) {
/* Turn the WDT off */
usb_pcwd_stop(usb_pcwd_device);
}
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static const struct file_operations usb_pcwd_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = usb_pcwd_write,
.ioctl = usb_pcwd_ioctl,
.open = usb_pcwd_open,
.release = usb_pcwd_release,
};
static struct miscdevice usb_pcwd_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &usb_pcwd_fops,
};
static const struct file_operations usb_pcwd_temperature_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = usb_pcwd_temperature_read,
.open = usb_pcwd_temperature_open,
.release = usb_pcwd_temperature_release,
};
static struct miscdevice usb_pcwd_temperature_miscdev = {
.minor = TEMP_MINOR,
.name = "temperature",
.fops = &usb_pcwd_temperature_fops,
};
static struct notifier_block usb_pcwd_notifier = {
.notifier_call = usb_pcwd_notify_sys,
};
/**
* usb_pcwd_delete
*/
static inline void usb_pcwd_delete (struct usb_pcwd_private *usb_pcwd)
{
if (usb_pcwd->intr_urb != NULL)
usb_free_urb (usb_pcwd->intr_urb);
if (usb_pcwd->intr_buffer != NULL)
usb_buffer_free(usb_pcwd->udev, usb_pcwd->intr_size,
usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
kfree (usb_pcwd);
}
/**
* usb_pcwd_probe
*
* Called by the usb core when a new device is connected that it thinks
* this driver might be interested in.
*/
static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
struct usb_device *udev = interface_to_usbdev(interface);
struct usb_host_interface *iface_desc;
struct usb_endpoint_descriptor *endpoint;
struct usb_pcwd_private *usb_pcwd = NULL;
int pipe, maxp;
int retval = -ENOMEM;
int got_fw_rev;
unsigned char fw_rev_major, fw_rev_minor;
char fw_ver_str[20];
unsigned char option_switches, dummy;
cards_found++;
if (cards_found > 1) {
printk(KERN_ERR PFX "This driver only supports 1 device\n");
return -ENODEV;
}
/* get the active interface descriptor */
iface_desc = interface->cur_altsetting;
/* check out that we have a HID device */
if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
printk(KERN_ERR PFX "The device isn't a Human Interface Device\n");
return -ENODEV;
}
/* check out the endpoint: it has to be Interrupt & IN */
endpoint = &iface_desc->endpoint[0].desc;
if (!((endpoint->bEndpointAddress & USB_DIR_IN) &&
((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
== USB_ENDPOINT_XFER_INT))) {
/* we didn't find a Interrupt endpoint with direction IN */
printk(KERN_ERR PFX "Couldn't find an INTR & IN endpoint\n");
return -ENODEV;
}
/* get a handle to the interrupt data pipe */
pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
/* allocate memory for our device and initialize it */
usb_pcwd = kmalloc (sizeof(struct usb_pcwd_private), GFP_KERNEL);
if (usb_pcwd == NULL) {
printk(KERN_ERR PFX "Out of memory\n");
goto error;
}
memset (usb_pcwd, 0x00, sizeof (*usb_pcwd));
usb_pcwd_device = usb_pcwd;
init_MUTEX (&usb_pcwd->sem);
usb_pcwd->udev = udev;
usb_pcwd->interface = interface;
usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8);
/* set up the memory buffer's */
if (!(usb_pcwd->intr_buffer = usb_buffer_alloc(udev, usb_pcwd->intr_size, SLAB_ATOMIC, &usb_pcwd->intr_dma))) {
printk(KERN_ERR PFX "Out of memory\n");
goto error;
}
/* allocate the urb's */
usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!usb_pcwd->intr_urb) {
printk(KERN_ERR PFX "Out of memory\n");
goto error;
}
/* initialise the intr urb's */
usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
usb_pcwd->intr_buffer, usb_pcwd->intr_size,
usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
/* register our interrupt URB with the USB system */
if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
printk(KERN_ERR PFX "Problem registering interrupt URB\n");
retval = -EIO; /* failure */
goto error;
}
/* The device exists and can be communicated with */
usb_pcwd->exists = 1;
/* disable card */
usb_pcwd_stop(usb_pcwd);
/* Get the Firmware Version */
got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor);
if (got_fw_rev) {
sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
} else {
sprintf(fw_ver_str, "<card no answer>");
}
printk(KERN_INFO PFX "Found card (Firmware: %s) with temp option\n",
fw_ver_str);
/* Get switch settings */
usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches);
printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
option_switches,
((option_switches & 0x10) ? "ON" : "OFF"),
((option_switches & 0x08) ? "ON" : "OFF"));
/* Check that the heartbeat value is within it's range ; if not reset to the default */
if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
WATCHDOG_HEARTBEAT);
}
retval = register_reboot_notifier(&usb_pcwd_notifier);
if (retval != 0) {
printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
retval);
goto error;
}
retval = misc_register(&usb_pcwd_temperature_miscdev);
if (retval != 0) {
printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
TEMP_MINOR, retval);
goto err_out_unregister_reboot;
}
retval = misc_register(&usb_pcwd_miscdev);
if (retval != 0) {
printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, retval);
goto err_out_misc_deregister;
}
/* we can register the device now, as it is ready */
usb_set_intfdata (interface, usb_pcwd);
printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
heartbeat, nowayout);
return 0;
err_out_misc_deregister:
misc_deregister(&usb_pcwd_temperature_miscdev);
err_out_unregister_reboot:
unregister_reboot_notifier(&usb_pcwd_notifier);
error:
if (usb_pcwd)
usb_pcwd_delete(usb_pcwd);
usb_pcwd_device = NULL;
return retval;
}
/**
* usb_pcwd_disconnect
*
* Called by the usb core when the device is removed from the system.
*
* This routine guarantees that the driver will not submit any more urbs
* by clearing dev->udev.
*/
static void usb_pcwd_disconnect(struct usb_interface *interface)
{
struct usb_pcwd_private *usb_pcwd;
/* prevent races with open() */
mutex_lock(&disconnect_mutex);
usb_pcwd = usb_get_intfdata (interface);
usb_set_intfdata (interface, NULL);
down (&usb_pcwd->sem);
/* Stop the timer before we leave */
if (!nowayout)
usb_pcwd_stop(usb_pcwd);
/* We should now stop communicating with the USB PCWD device */
usb_pcwd->exists = 0;
/* Deregister */
misc_deregister(&usb_pcwd_miscdev);
misc_deregister(&usb_pcwd_temperature_miscdev);
unregister_reboot_notifier(&usb_pcwd_notifier);
up (&usb_pcwd->sem);
/* Delete the USB PCWD device */
usb_pcwd_delete(usb_pcwd);
cards_found--;
mutex_unlock(&disconnect_mutex);
printk(KERN_INFO PFX "USB PC Watchdog disconnected\n");
}
/**
* usb_pcwd_init
*/
static int __init usb_pcwd_init(void)
{
int result;
/* register this driver with the USB subsystem */
result = usb_register(&usb_pcwd_driver);
if (result) {
printk(KERN_ERR PFX "usb_register failed. Error number %d\n",
result);
return result;
}
printk(KERN_INFO PFX DRIVER_DESC " v" DRIVER_VERSION " (" DRIVER_DATE ")\n");
return 0;
}
/**
* usb_pcwd_exit
*/
static void __exit usb_pcwd_exit(void)
{
/* deregister this driver with the USB subsystem */
usb_deregister(&usb_pcwd_driver);
}
module_init (usb_pcwd_init);
module_exit (usb_pcwd_exit);
