linux下usb驱动代码示例

好的，以下是一个简单的Linux USB驱动程序示例代码，实现了对USB设备的读写操作：

#include <linux/module.h>
#include <linux/usb.h>
#include <linux/slab.h>
#include <linux/uaccess.h>

#define USB_VENDOR_ID   0xXXXX  // 请替换为实际的USB设备的Vendor ID
#define USB_PRODUCT_ID  0xXXXX  // 请替换为实际的USB设备的Product ID

static struct usb_device_id my_usb_table[] = {
    { USB_DEVICE(USB_VENDOR_ID, USB_PRODUCT_ID) },
    { }
};
MODULE_DEVICE_TABLE(usb, my_usb_table);

static int my_usb_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
    struct usb_device *dev = interface_to_usbdev(interface);
    struct usb_endpoint_descriptor *ep_desc;
    struct usb_host_interface *iface_desc;
    unsigned char *buffer;
    int retval = -ENOMEM;
    int i;

    printk(KERN_INFO "My USB device (%04X:%04X) plugged in\n", id->idVendor, id->idProduct);
    printk(KERN_INFO "Number of endpoints: %d\n", interface->cur_altsetting->desc.bNumEndpoints);

    iface_desc = interface->cur_altsetting;
    for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
        ep_desc = &iface_desc->endpoint[i].desc;
        if (usb_endpoint_is_bulk_in(ep_desc)) {
            printk(KERN_INFO "Bulk IN endpoint found\n");
        }
        if (usb_endpoint_is_bulk_out(ep_desc)) {
            printk(KERN_INFO "Bulk OUT endpoint found\n");
        }
    }

    buffer = kmalloc(64, GFP_KERNEL);
    if (!buffer) {
        printk(KERN_ERR "Failed to allocate memory for buffer\n");
        return -ENOMEM;
    }

    retval = usb_bulk_msg(dev, usb_rcvbulkpipe(dev, 0x81), buffer, 64, NULL, 5000);
    if (retval < 0) {
        printk(KERN_ERR "Failed to read data from USB device (%d)\n", retval);
        goto error;
    }

    printk(KERN_INFO "Data read from USB device: ");
    for (i = 0; i < 64; i++) {
        printk("%02X ", buffer[i]);
    }
    printk("\n");

    retval = usb_bulk_msg(dev, usb_sndbulkpipe(dev, 0x01), "Hello World!", strlen("Hello World!") + 1, NULL, 5000);
    if (retval < 0) {
        printk(KERN_ERR "Failed to write data to USB device (%d)\n", retval);
        goto error;
    }

    kfree(buffer);
    return 0;

error:
    kfree(buffer);
    return retval;
}

static void my_usb_disconnect(struct usb_interface *interface)
{
    printk(KERN_INFO "My USB device removed\n");
}

static struct usb_driver my_usb_driver = {
    .name = "my_usb_driver",
    .id_table = my_usb_table,
    .probe = my_usb_probe,
    .disconnect = my_usb_disconnect,
};

static int __init my_usb_init(void)
{
    int retval;

    retval = usb_register(&my_usb_driver);
    if (retval < 0) {
        printk(KERN_ERR "Failed to register USB driver (%d)\n", retval);
        return retval;
    }

    printk(KERN_INFO "My USB driver module loaded\n");
    return 0;
}

static void __exit my_usb_exit(void)
{
    usb_deregister(&my_usb_driver);
    printk(KERN_INFO "My USB driver module unloaded\n");
}

module_init(my_usb_init);
module_exit(my_usb_exit);
MODULE_LICENSE("GPL");

这段代码实现了一个名为my_usb_driver的USB驱动程序，用于与指定的USB设备通信。在probe函数中，我们获取了设备的Endpoint信息，并使用usb_bulk_msg函数进行了读写操作。在disconnect函数中，我们简单地输出了设备的移除信息。

需要注意的是，此代码中的USB_VENDOR_ID和USB_PRODUCT_ID需要替换为实际的USB设备的Vendor ID和Product ID。这些信息可以通过使用lsusb命令来获取。另外，在编译此代码时，需要链接USB库。可以使用以下命令进行编译：

make -C /lib/modules/$(uname -r)/build M=$(pwd) modules

其中，$(uname -r)用于获取当前Linux内核的版本号。