Linux驱动程序笔记5——usb概述2

struct usb_device {

intdevnum;     //设备号，也称设备地址

chardevpath[16];

u32route;

enum usb_device_statestate; 

enum usb_device_speedspeed; 

struct usb_tt*tt;

intttport;

unsigned int toggle[2];

struct usb_device *parent;

struct usb_bus *bus;     //usb设备所在的总线

        //0号端口，可以双向传输

struct usb_host_endpoint ep0; //usb主机端口结构体，详见注释1

struct device dev;

struct usb_device_descriptor descriptor;//usb设备描述符，详见注释2

struct usb_host_bos *bos;

struct usb_host_config *config;

struct usb_host_config *actconfig; //配置结构体，详见注释3

         //由此我们看出usb最多支持33个端口，1个控制端口，16个输入端口，16个输出端口

struct usb_host_endpoint *ep_in[16];//输入端口

struct usb_host_endpoint *ep_out[16];//输出端口

char **rawdescriptors;

unsigned short bus_mA;

u8 portnum;

u8 level;

unsigned can_submit:1;

unsigned persist_enabled:1;

unsigned have_langid:1;

unsigned authorized:1;

unsigned authenticated:1;

unsigned wusb:1;

unsigned lpm_capable:1;

unsigned usb2_hw_lpm_capable:1;

unsigned usb2_hw_lpm_enabled:1;

int string_langid;

/* static strings from the device */

char *product;

char *manufacturer;

char *serial;

struct list_head filelist;

#ifdef CONFIG_USB_DEVICE_CLASS

struct device *usb_classdev;

#endif

#ifdef CONFIG_USB_DEVICEFS

struct dentry *usbfs_dentry;

#endif

int maxchild;

struct usb_device **children;

u32 quirks;

atomic_t urbnum;

unsigned long active_duration;

#ifdef CONFIG_PM

unsigned long connect_time;

unsigned do_remote_wakeup:1;

unsigned reset_resume:1;

#endif

struct wusb_dev *wusb_dev;

int slot_id;

enum usb_device_removable removable;

};

注释1：

struct usb_host_endpoint {

struct usb_endpoint_descriptordesc; //端口描述符，详见注释1-1

struct usb_ss_ep_comp_descriptorss_ep_comp;

struct list_headurb_list;  //本端点的请求块的队列

void*hcpriv;

struct ep_device*ep_dev; /* For sysfs info */

unsigned char *extra;   /* Extra descriptors */

int extralen;

int enabled;

};

注释1-1：

struct usb_endpoint_descriptor {

__u8  bLength;

__u8  bDescriptorType;

__u8  bEndpointAddress;  //端口地址

__u8  bmAttributes;

__le16 wMaxPacketSize; //一次传输的最大数据量

__u8  bInterval;

/* NOTE:  these two are _only_ in audio endpoints. */

/* use USB_DT_ENDPOINT*_SIZE in bLength, not sizeof. */

__u8  bRefresh;

__u8  bSynchAddress;

} __attribute__ ((packed));

注释2：

struct usb_device_descriptor {

__u8  bLength;

__u8  bDescriptorType;

__le16 bcdUSB;

__u8  bDeviceClass;

__u8  bDeviceSubClass;

__u8  bDeviceProtocol;

__u8  bMaxPacketSize0;//一次传输的最大数据量

__le16 idVendor;

__le16 idProduct;

__le16 bcdDevice;

__u8  iManufacturer;

__u8  iProduct;

__u8  iSerialNumber;

__u8  bNumConfigurations;

} __attribute__ ((packed));

注释3：

struct usb_host_config {

struct usb_config_descriptordesc; //配置描述符，详见注释3-1

char *string;/* iConfiguration string, if present */

         //接口代表一种功能，而配置是功能的组合

struct usb_interface_assoc_descriptor *intf_assoc[USB_MAXIADS];

/* the interfaces associated with this configuration,

 * stored in no particular order */

struct usb_interface *interface[USB_MAXINTERFACES];

/* Interface information available even when this is not the

 * active configuration */

struct usb_interface_cache *intf_cache[USB_MAXINTERFACES];

unsigned char *extra;   /* Extra descriptors */

int extralen;

};