计操理论课07 -- openEuler实验第六章设备管理

任务1：编写USB设备驱动程序（40min）

任务要求

1. 参考内核源码中的drivers/usb/usb-skeleton.c文件，编写一个USB探测驱动程序，能够实现以下基本功能：
   （1）在插入U盘时能够探测到；
   （2）在拔出U盘时能够探测到；
2. 加载、卸载模块并查看模块打印信息。

任务代码

usb_detect.c

/*
 * USB Detect driver
 *
 * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c
 */

#include <linux/kernel.h>
#include <linux/errno.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_DETECT_VENDOR_ID	0x0951
#define USB_DETECT_PRODUCT_ID	0x160b

/* table of devices that work with this driver */
static const struct usb_device_id usbdetect_table[] = {
   
	{
    USB_DEVICE(USB_DETECT_VENDOR_ID, USB_DETECT_PRODUCT_ID) },
	{
    }					/* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, usbdetect_table);


/* Get a minor range for your devices from the usb maintainer */
#define USB_DETECT_MINOR_BASE	192

#define WRITES_IN_FLIGHT	8
/* arbitrarily chosen */

/* Structure to hold all of our device specific stuff */
struct usb_detect {
   
	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 */
	bool			ongoing_read;		/* a read is going on */
	spinlock_t		err_lock;		/* lock for errors */
	struct kref		kref;
	struct mutex		io_mutex;		/* synchronize I/O with disconnect */
	unsigned long		disconnected:1;
	wait_queue_head_t	bulk_in_wait;		/* to wait for an ongoing read */
};
#define to_detect_dev(d) container_of(d, struct usb_detect, kref)

static struct usb_driver usbdetect_driver;

static void usbdetect_delete(struct kref *kref)
{
   
	struct usb_detect *dev = to_detect_dev(kref);

	usb_free_urb(dev->bulk_in_urb);
	usb_put_intf(dev->interface);
	usb_put_dev(dev->udev);
	kfree(dev->bulk_in_buffer);
	kfree(dev);
}

static const struct file_operations usbdetect_fops = {
   };

/*
 * usb class driver info in order to get a minor number from