进行ch341相关的usb设备读写.
在插入usb设备驱动模块usb-skeleton.ko之后,可通过/dev/skel0文件读写usb设备.
先写十几个byte的字符, 然后再读设备. 读写
/dev/skel0文件的代码如下:
-
#include <stdio.h>
-
#include <string.h>
-
#include <unistd.h>
-
#include <fcntl.h>
-
#include <errno.h>
-
#include <termios.h>
-
-
-
int main(int argc, char* argv[])
-
{
-
int fd; /* File descriptor for the port */
-
int i;
-
int iRet;
-
char *ptr = "1234567890abcdef";
-
size_t count = 16;
-
char buf[1024];
-
-
if(argc >= 2) {
-
ptr = argv[1];
-
count = strlen(argv[1]);
-
}
-
printf("[%s-%d]tracing: \n", __FILE__, __LINE__);
-
fd = open("/dev/skel0", O_RDWR);
-
if (fd < 0) { /** error **/
-
perror("open");
-
printf("[%s-%d] open error!!!\n", __FILE__, __LINE__);
-
iRet = fd;
-
goto err1;
-
}
-
//iRet = write(fd, "1234567890abcdef", 16);
-
iRet = write(fd, ptr, count);
-
if (iRet < 0) {
-
printf("[%s-%d] write error!!!\n", __FILE__, __LINE__);
-
}
-
-
iRet = read(fd, buf, count);
-
if (iRet < 0) {
-
printf("[%s-%d] read error!!!\n", __FILE__, __LINE__);
-
} else {
-
for(i = 0; i < iRet; i++) {
-
printf("[0x%02x - %c]", buf[i], buf[i]);
-
}
-
printf("\n");
-
}
-
-
close(fd);
-
err1:
-
return iRet;
-
}
1.编译, 运行此代码, 发现ch341接到com串口的一端收到乱码, 并且程序卡住了, ch341接到com串口的一端发出数据后, 没打印输出, 程序仍卡住. "ctrl+c"也不能退出.
2.从现象可猜测, 数据写的过程已完成, 程序很可能卡在读数据上. 对usb-skeleton.c文件中的skel_read()函数中及其调用的函数中所有可能卡住的地方加"printk("[%s-%d]tracing !\n", __func__, __LINE__);"打印执行路径的语句. 发现代码卡在"wait_for_completion(&dev->bulk_in_completion);"
3.分析其执行条件if (!dev->processed_urb) {...}. 查看代码, 没有发现其它地方对其清零. 也没有初始化清零的动作. 从代码注释看初始化更应该是置1. 猜测是dev->processed_urb初始设置错误. 在skel_probe()函数中加入初始置1的代码"dev->processed_urb = 1;". 重新编译/插入模块/运行代码. 程序运行后停下, ch341接到com串口的一端发出数据后, 有打印输出, 然后程序退出. 至此, 收发操作都有. 然而收到后打印的数据并非ch341对端发出的数据.
4.考虑到ch341芯片是专门用于usb转串口的, 而RS-232串口有特定的通信波特率/校验位/数据位/停止位, 而本实验中并没有进行相应设置. 传输乱码可能的原因是其中一项设置不一致造成的. 抱着试一试的想法, 将ch341接串口一端的串口调试助手的通信波特率由115200到300挨个试, 发现波特率为19200时, ch341接口两端都收到对方发来的数据, 并且数据收发正确. 暂没发现其它问题.
修改后的usb-skeletion.c内容如下:
-
/*
-
* USB Skeleton driver - 2.2
-
*
-
* Copyright (C) 2001-2004 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, version 2.
-
*
-
* This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c
-
* but has been rewritten to be easier to read and use.
-
*
-
*/
-
-
#include <linux/kernel.h>
-
#include <linux/errno.h>
-
#include <linux/init.h>
-
#include <linux/slab.h>
-
#include <linux/module.h>
-
#include <linux/kref.h>
-
#include <linux/uaccess.h>
-
#include <linux/usb.h>
-
#include <linux/mutex.h>
-
-
-
/* Define these values to match your devices */
-
#define USB_SKEL_VENDOR_ID 0x1A86
-
#define USB_SKEL_PRODUCT_ID 0x7523
-
-
/* table of devices that work with this driver */
-
static const struct usb_device_id skel_table[] = {
-
{ USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
-
{ } /* Terminating entry */
-
};
-
MODULE_DEVICE_TABLE(usb, skel_table);
-
-
-
/* Get a minor range for your devices from the usb maintainer */
-
#define USB_SKEL_MINOR_BASE 192
-
-
/* our private defines. if this grows any larger, use your own .h file */
-
#define MAX_TRANSFER (PAGE_SIZE - 512)
-
/* MAX_TRANSFER is chosen so that the VM is not stressed by
-
allocations > PAGE_SIZE and the number of packets in a page
-
is an integer 512 is the largest possible packet on EHCI */
-
#define WRITES_IN_FLIGHT 8
-
/* arbitrarily chosen */
-
-
/* Structure to hold all of our device specific stuff */
-
struct usb_skel {
-
struct usb_device *udev; /* the usb device for this device */
-
struct usb_interface *interface; /* the interface for this device */
-
struct semaphore limit_sem; /* limiting the number of writes in progress */
-
struct usb_anchor submitted; /* in case we need to retract our submissions */
-
struct urb *bulk_in_urb; /* the urb to read data with */
-
unsigned char *bulk_in_buffer; /* the buffer to receive data */
-
size_t bulk_in_size; /* the size of the receive buffer */
-
size_t bulk_in_filled; /* number of bytes in the buffer */
-
size_t bulk_in_copied; /* already copied to user space */
-
__u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */
-
__u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */
-
int errors; /* the last request tanked */
-
int open_count; /* count the number of openers */
-
bool ongoing_read; /* a read is going on */
-
bool processed_urb; /* indicates we haven't processed the urb */
-
spinlock_t err_lock; /* lock for errors */
-
struct kref kref;
-
struct mutex io_mutex; /* synchronize I/O with disconnect */
-
struct completion bulk_in_completion; /* to wait for an ongoing read */
-
};
-
#define to_skel_dev(d) container_of(d, struct usb_skel, kref)
-
-
static struct usb_driver skel_driver;
-
static void skel_draw_down(struct usb_skel *dev);
-
-
static void skel_delete(struct kref *kref)
-
{
-
struct usb_skel *dev = to_skel_dev(kref);
-
-
usb_free_urb(dev->bulk_in_urb);
-
usb_put_dev(dev->udev);
-
kfree(dev->bulk_in_buffer);
-
kfree(dev);
-
}
-
-
static int skel_open(struct inode *inode, struct file *file)
-
{
-
struct usb_skel *dev;
-
struct usb_interface *interface;
-
int subminor;
-
int retval = 0;
-
-
subminor = iminor(inode);
-
-
interface = usb_find_interface(&skel_driver, subminor);
-
if (!interface) {
-
err("%s - error, can't find device for minor %d",
-
__func__, subminor);
-
retval = -ENODEV;
-
goto exit;
-
}
-
-
dev = usb_get_intfdata(interface);
-
if (!dev) {
-
retval = -ENODEV;
-
goto exit;
-
}
-
-
/* increment our usage count for the device */
-
kref_get(&dev->kref);
-
-
/* lock the device to allow correctly handling errors
-
* in resumption */
-
mutex_lock(&dev->io_mutex);
-
-
if (!dev->open_count++) {
-
retval = usb_autopm_get_interface(interface);
-
if (retval) {
-
dev->open_count--;
-
mutex_unlock(&dev->io_mutex);
-
kref_put(&dev->kref, skel_delete);
-
goto exit;
-
}
-
} /* else { //uncomment this block if you want exclusive open
-
retval = -EBUSY;
-
dev->open_count--;
-
mutex_unlock(&dev->io_mutex);
-
kref_put(&dev->kref, skel_delete);
-
goto exit;
-
} */
-
/* prevent the device from being autosuspended */
-
-
/* save our object in the file's private structure */
-
file->private_data = dev;
-
mutex_unlock(&dev->io_mutex);
-
-
exit:
-
return retval;
-
}
-
-
static int skel_release(struct inode *inode, struct file *file)
-
{
-
struct usb_skel *dev;
-
-
dev = file->private_data;
-
if (dev == NULL)
-
return -ENODEV;
-
-
/* allow the device to be autosuspended */
-
mutex_lock(&dev->io_mutex);
-
if (!--dev->open_count && dev->interface)
-
usb_autopm_put_interface(dev->interface);
-
mutex_unlock(&dev->io_mutex);
-
-
/* decrement the count on our device */
-
kref_put(&dev->kref, skel_delete);
-
return 0;
-
}
-
-
static int skel_flush(struct file *file, fl_owner_t id)
-
{
-
struct usb_skel *dev;
-
int res;
-
-
dev = file->private_data;
-
if (dev == NULL)
-
return -ENODEV;
-
-
/* wait for io to stop */
-
mutex_lock(&dev->io_mutex);
-
skel_draw_down(dev);
-
-
/* read out errors, leave subsequent opens a clean slate */
-
spin_lock_irq(&dev->err_lock);
-
res = dev->errors ? (dev->errors == -EPIPE ? -EPIPE : -EIO) : 0;
-
dev->errors = 0;
-
spin_unlock_irq(&dev->err_lock);
-
-
mutex_unlock(&dev->io_mutex);
-
-
return res;
-
}
-
-
static void skel_read_bulk_callback(struct urb *urb)
-
{
-
struct usb_skel *dev;
-
-
dev = urb->context;
-
-
spin_lock(&dev->err_lock);
-
/* sync/async unlink faults aren't errors */
-
if (urb->status) {
-
if (!(urb->status == -ENOENT ||
-
urb->status == -ECONNRESET ||
-
urb->status == -ESHUTDOWN))
-
err("%s - nonzero write bulk status received: %d",
-
__func__, urb->status);
-
-
dev->errors = urb->status;
-
} else {
-
dev->bulk_in_filled = urb->actual_length;
-
}
-
dev->ongoing_read = 0;
-
spin_unlock(&dev->err_lock);
-
-
complete(&dev->bulk_in_completion);
-
}
-
-
static int skel_do_read_io(struct usb_skel *dev, size_t count)
-
{
-
int rv;
-
-
/* prepare a read */
-
usb_fill_bulk_urb(dev->bulk_in_urb,
-
dev->udev,
-
usb_rcvbulkpipe(dev->udev,
-
dev->bulk_in_endpointAddr),
-
dev->bulk_in_buffer,
-
min(dev->bulk_in_size, count),
-
skel_read_bulk_callback,
-
dev);
-
/* tell everybody to leave the URB alone */
-
spin_lock_irq(&dev->err_lock);
-
dev->ongoing_read = 1;
-
spin_unlock_irq(&dev->err_lock);
-
-
/* do it */
-
rv = usb_submit_urb(dev->bulk_in_urb, GFP_KERNEL);
-
if (rv < 0) {
-
err("%s - failed submitting read urb, error %d",
-
__func__, rv);
-
dev->bulk_in_filled = 0;
-
rv = (rv == -ENOMEM) ? rv : -EIO;
-
spin_lock_irq(&dev->err_lock);
-
dev->ongoing_read = 0;
-
spin_unlock_irq(&dev->err_lock);
-
}
-
-
return rv;
-
}
-
-
static ssize_t skel_read(struct file *file, char *buffer, size_t count,
-
loff_t *ppos)
-
{
-
struct usb_skel *dev;
-
int rv;
-
bool ongoing_io;
-
-
dev = file->private_data;
-
-
/* if we cannot read at all, return EOF */
-
if (!dev->bulk_in_urb || !count)
-
return 0;
-
-
/* no concurrent readers */
-
rv = mutex_lock_interruptible(&dev->io_mutex);
-
if (rv < 0)
-
return rv;
-
-
if (!dev->interface) { /* disconnect() was called */
-
rv = -ENODEV;
-
goto exit;
-
}
-
-
/* if IO is under way, we must not touch things */
-
retry:
-
spin_lock_irq(&dev->err_lock);
-
ongoing_io = dev->ongoing_read;
-
spin_unlock_irq(&dev->err_lock);
-
-
if (ongoing_io) {
-
/* nonblocking IO shall not wait */
-
if (file->f_flags & O_NONBLOCK) {
-
rv = -EAGAIN;
-
goto exit;
-
}
-
/*
-
* IO may take forever
-
* hence wait in an interruptible state
-
*/
-
rv = wait_for_completion_interruptible(&dev->bulk_in_completion);
-
if (rv < 0)
-
goto exit;
-
/*
-
* by waiting we also semiprocessed the urb
-
* we must finish now
-
*/
-
dev->bulk_in_copied = 0;
-
dev->processed_urb = 1;
-
}
-
-
if (!dev->processed_urb) {
-
/*
-
* the URB hasn't been processed
-
* do it now
-
*/
-
wait_for_completion(&dev->bulk_in_completion);
-
dev->bulk_in_copied = 0;
-
dev->processed_urb = 1;
-
}
-
-
/* errors must be reported */
-
rv = dev->errors;
-
if (rv < 0) {
-
/* any error is reported once */
-
dev->errors = 0;
-
/* to preserve notifications about reset */
-
rv = (rv == -EPIPE) ? rv : -EIO;
-
/* no data to deliver */
-
dev->bulk_in_filled = 0;
-
/* report it */
-
goto exit;
-
}
-
-
/*
-
* if the buffer is filled we may satisfy the read
-
* else we need to start IO
-
*/
-
-
if (dev->bulk_in_filled) {
-
/* we had read data */
-
size_t available = dev->bulk_in_filled - dev->bulk_in_copied;
-
size_t chunk = min(available, count);
-
-
if (!available) {
-
/*
-
* all data has been used
-
* actual IO needs to be done
-
*/
-
rv = skel_do_read_io(dev, count);
-
if (rv < 0)
-
goto exit;
-
else
-
goto retry;
-
}
-
/*
-
* data is available
-
* chunk tells us how much shall be copied
-
*/
-
-
if (copy_to_user(buffer,
-
dev->bulk_in_buffer + dev->bulk_in_copied,
-
chunk))
-
rv = -EFAULT;
-
else
-
rv = chunk;
-
-
dev->bulk_in_copied += chunk;
-
-
/*
-
* if we are asked for more than we have,
-
* we start IO but don't wait
-
*/
-
if (available < count)
-
skel_do_read_io(dev, count - chunk);
-
} else {
-
/* no data in the buffer */
-
rv = skel_do_read_io(dev, count);
-
if (rv < 0)
-
goto exit;
-
else if (!(file->f_flags & O_NONBLOCK))
-
goto retry;
-
rv = -EAGAIN;
-
}
-
exit:
-
mutex_unlock(&dev->io_mutex);
-
return rv;
-
}
-
-
static void skel_write_bulk_callback(struct urb *urb)
-
{
-
struct usb_skel *dev;
-
-
dev = urb->context;
-
-
/* sync/async unlink faults aren't errors */
-
if (urb->status) {
-
if (!(urb->status == -ENOENT ||
-
urb->status == -ECONNRESET ||
-
urb->status == -ESHUTDOWN))
-
err("%s - nonzero write bulk status received: %d",
-
__func__, urb->status);
-
-
spin_lock(&dev->err_lock);
-
dev->errors = urb->status;
-
spin_unlock(&dev->err_lock);
-
}
-
-
/* free up our allocated buffer */
-
usb_free_coherent(urb->dev, urb->transfer_buffer_length,
-
urb->transfer_buffer, urb->transfer_dma);
-
up(&dev->limit_sem);
-
}
-
-
static ssize_t skel_write(struct file *file, const char *user_buffer,
-
size_t count, loff_t *ppos)
-
{
-
struct usb_skel *dev;
-
int retval = 0;
-
struct urb *urb = NULL;
-
char *buf = NULL;
-
size_t writesize = min(count, (size_t)MAX_TRANSFER);
-
-
dev = file->private_data;
-
-
/* verify that we actually have some data to write */
-
if (count == 0)
-
goto exit;
-
-
/*
-
* limit the number of URBs in flight to stop a user from using up all
-
* RAM
-
*/
-
if (!(file->f_flags & O_NONBLOCK)) {
-
if (down_interruptible(&dev->limit_sem)) {
-
retval = -ERESTARTSYS;
-
goto exit;
-
}
-
} else {
-
if (down_trylock(&dev->limit_sem)) {
-
retval = -EAGAIN;
-
goto exit;
-
}
-
}
-
-
spin_lock_irq(&dev->err_lock);
-
retval = dev->errors;
-
if (retval < 0) {
-
/* any error is reported once */
-
dev->errors = 0;
-
/* to preserve notifications about reset */
-
retval = (retval == -EPIPE) ? retval : -EIO;
-
}
-
spin_unlock_irq(&dev->err_lock);
-
if (retval < 0)
-
goto error;
-
-
/* create a urb, and a buffer for it, and copy the data to the urb */
-
urb = usb_alloc_urb(0, GFP_KERNEL);
-
if (!urb) {
-
retval = -ENOMEM;
-
goto error;
-
}
-
-
buf = usb_alloc_coherent(dev->udev, writesize, GFP_KERNEL,
-
&urb->transfer_dma);
-
if (!buf) {
-
retval = -ENOMEM;
-
goto error;
-
}
-
-
if (copy_from_user(buf, user_buffer, writesize)) {
-
retval = -EFAULT;
-
goto error;
-
}
-
-
/* this lock makes sure we don't submit URBs to gone devices */
-
mutex_lock(&dev->io_mutex);
-
if (!dev->interface) { /* disconnect() was called */
-
mutex_unlock(&dev->io_mutex);
-
retval = -ENODEV;
-
goto error;
-
}
-
-
/* initialize the urb properly */
-
usb_fill_bulk_urb(urb, dev->udev,
-
usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
-
buf, writesize, skel_write_bulk_callback, dev);
-
urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
-
usb_anchor_urb(urb, &dev->submitted);
-
-
/* send the data out the bulk port */
-
retval = usb_submit_urb(urb, GFP_KERNEL);
-
mutex_unlock(&dev->io_mutex);
-
if (retval) {
-
err("%s - failed submitting write urb, error %d", __func__,
-
retval);
-
goto error_unanchor;
-
}
-
-
/*
-
* release our reference to this urb, the USB core will eventually free
-
* it entirely
-
*/
-
usb_free_urb(urb);
-
-
-
return writesize;
-
-
error_unanchor:
-
usb_unanchor_urb(urb);
-
error:
-
if (urb) {
-
usb_free_coherent(dev->udev, writesize, buf, urb->transfer_dma);
-
usb_free_urb(urb);
-
}
-
up(&dev->limit_sem);
-
-
exit:
-
return retval;
-
}
-
-
static const struct file_operations skel_fops = {
-
.owner = THIS_MODULE,
-
.read = skel_read,
-
.write = skel_write,
-
.open = skel_open,
-
.release = skel_release,
-
.flush = skel_flush,
-
.llseek = noop_llseek,
-
};
-
-
/*
-
* usb class driver info in order to get a minor number from the usb core,
-
* and to have the device registered with the driver core
-
*/
-
static struct usb_class_driver skel_class = {
-
.name = "skel%d",
-
.fops = &skel_fops,
-
.minor_base = USB_SKEL_MINOR_BASE,
-
};
-
-
static int skel_probe(struct usb_interface *interface,
-
const struct usb_device_id *id)
-
{
-
struct usb_skel *dev;
-
struct usb_host_interface *iface_desc;
-
struct usb_endpoint_descriptor *endpoint;
-
size_t buffer_size;
-
int i;
-
int retval = -ENOMEM;
-
-
/* allocate memory for our device state and initialize it */
-
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-
if (!dev) {
-
err("Out of memory");
-
goto error;
-
}
-
kref_init(&dev->kref);
-
sema_init(&dev->limit_sem, WRITES_IN_FLIGHT);
-
mutex_init(&dev->io_mutex);
-
spin_lock_init(&dev->err_lock);
-
init_usb_anchor(&dev->submitted);
-
init_completion(&dev->bulk_in_completion);
-
-
dev->udev = usb_get_dev(interface_to_usbdev(interface));
-
dev->interface = interface;
-
-
dev->processed_urb = 1; //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-
/* set up the endpoint information */
-
/* use only the first bulk-in and bulk-out endpoints */
-
iface_desc = interface->cur_altsetting;
-
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
-
endpoint = &iface_desc->endpoint[i].desc;
-
-
if (!dev->bulk_in_endpointAddr &&
-
usb_endpoint_is_bulk_in(endpoint)) {
-
/* we found a bulk in endpoint */
-
buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
-
dev->bulk_in_size = buffer_size;
-
dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
-
dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
-
if (!dev->bulk_in_buffer) {
-
err("Could not allocate bulk_in_buffer");
-
goto error;
-
}
-
dev->bulk_in_urb = usb_alloc_urb(0, GFP_KERNEL);
-
if (!dev->bulk_in_urb) {
-
err("Could not allocate bulk_in_urb");
-
goto error;
-
}
-
}
-
-
if (!dev->bulk_out_endpointAddr &&
-
usb_endpoint_is_bulk_out(endpoint)) {
-
/* we found a bulk out endpoint */
-
dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
-
}
-
}
-
if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
-
err("Could not find both bulk-in and bulk-out endpoints");
-
goto error;
-
}
-
-
/* save our data pointer in this interface device */
-
usb_set_intfdata(interface, dev);
-
-
/* we can register the device now, as it is ready */
-
retval = usb_register_dev(interface, &skel_class);
-
if (retval) {
-
/* something prevented us from registering this driver */
-
err("Not able to get a minor for this device.");
-
usb_set_intfdata(interface, NULL);
-
goto error;
-
}
-
-
/* let the user know what node this device is now attached to */
-
dev_info(&interface->dev,
-
"USB Skeleton device now attached to USBSkel-%d",
-
interface->minor);
-
return 0;
-
-
error:
-
if (dev)
-
/* this frees allocated memory */
-
kref_put(&dev->kref, skel_delete);
-
return retval;
-
}
-
-
static void skel_disconnect(struct usb_interface *interface)
-
{
-
struct usb_skel *dev;
-
int minor = interface->minor;
-
-
dev = usb_get_intfdata(interface);
-
usb_set_intfdata(interface, NULL);
-
-
/* give back our minor */
-
usb_deregister_dev(interface, &skel_class);
-
-
/* prevent more I/O from starting */
-
mutex_lock(&dev->io_mutex);
-
dev->interface = NULL;
-
mutex_unlock(&dev->io_mutex);
-
-
usb_kill_anchored_urbs(&dev->submitted);
-
-
/* decrement our usage count */
-
kref_put(&dev->kref, skel_delete);
-
-
dev_info(&interface->dev, "USB Skeleton #%d now disconnected", minor);
-
}
-
-
static void skel_draw_down(struct usb_skel *dev)
-
{
-
int time;
-
-
time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
-
if (!time)
-
usb_kill_anchored_urbs(&dev->submitted);
-
usb_kill_urb(dev->bulk_in_urb);
-
}
-
-
static int skel_suspend(struct usb_interface *intf, pm_message_t message)
-
{
-
struct usb_skel *dev = usb_get_intfdata(intf);
-
-
if (!dev)
-
return 0;
-
skel_draw_down(dev);
-
return 0;
-
}
-
-
static int skel_resume(struct usb_interface *intf)
-
{
-
return 0;
-
}
-
-
static int skel_pre_reset(struct usb_interface *intf)
-
{
-
struct usb_skel *dev = usb_get_intfdata(intf);
-
-
mutex_lock(&dev->io_mutex);
-
skel_draw_down(dev);
-
-
return 0;
-
}
-
-
static int skel_post_reset(struct usb_interface *intf)
-
{
-
struct usb_skel *dev = usb_get_intfdata(intf);
-
-
/* we are sure no URBs are active - no locking needed */
-
dev->errors = -EPIPE;
-
mutex_unlock(&dev->io_mutex);
-
-
return 0;
-
}
-
-
static struct usb_driver skel_driver = {
-
.name = "skeleton",
-
.probe = skel_probe,
-
.disconnect = skel_disconnect,
-
.suspend = skel_suspend,
-
.resume = skel_resume,
-
.pre_reset = skel_pre_reset,
-
.post_reset = skel_post_reset,
-
.id_table = skel_table,
-
.supports_autosuspend = 1,
-
};
-
-
static int __init usb_skel_init(void)
-
{
-
int result;
-
-
/* register this driver with the USB subsystem */
-
result = usb_register(&skel_driver);
-
if (result)
-
err("usb_register failed. Error number %d", result);
-
-
return result;
-
}
-
-
static void __exit usb_skel_exit(void)
-
{
-
/* deregister this driver with the USB subsystem */
-
usb_deregister(&skel_driver);
-
}
-
-
module_init(usb_skel_init);
-
module_exit(usb_skel_exit);
-
-
MODULE_LICENSE("GPL");
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