# USB服务子系统概述<a name="ZH-CN_TOPIC_0000001092893508"></a>


## 概述<a name="section175431838101617"></a>

  USB设备分为Host设备（主机设备）和Device设备（从设备）。用户可通过Port Service来根据实际业务把运行OpenHarmony的设备切换为Host设备或者Device设备。目前在Host模式下，支持获取USB设备列表，USB设备权限管理，控制传输、批量传输的同异步数据传输等，在Device模式下，支持HDC（调试）、ACM（串口）、ECM（网口）等功能的切换。

**图1**  USB服务架构图

![](figure/USB服务架构图.png)

-   USB FWK/API：基于USB Service服务，使用NAPI技术，向上提供JS接口。
-   USB Service：使用C++代码实现，包含Host、Device、Port三个模块。基于HDI的接口，主要实现USB设备的列表管理、Function 管理、Port管理、USB设备权限管理等功能。
-   USB HAL：使用C代码实现，基于Host SDK和Device SDK，封装了对USB设备的基本操作，向上提供C++接口，同时通过HDF框架接收内核上报的信息。

## 接口说明<a name="section83365421647"></a>

- ### Host部分<a name="section83365421658"></a>

<a name="table1513255710559"></a>
<table><thead align="left"><tr id="row171321857155517"><th class="cellrowborder" valign="top" width="10.721072107210723%" id="mcps1.2.4.1.1"><p id="p6132957115511"><a name="p6132957115511"></a><a name="p6132957115511"></a>头文件</p>
</th>
<th class="cellrowborder" valign="top" width="66.36663666366637%" id="mcps1.2.4.1.2"><p id="p14132125715552"><a name="p14132125715552"></a><a name="p14132125715552"></a>接口名称</p>
</th>
<th class="cellrowborder" valign="top" width="22.912291229122914%" id="mcps1.2.4.1.3"><p id="p18132205755516"><a name="p18132205755516"></a><a name="p18132205755516"></a>功能描述</p>
</th>
</tr>
</thead>
<tbody><tr id="row13132357165514"><td class="cellrowborder" rowspan="16" valign="top" width="10.721072107210723%" headers="mcps1.2.4.1.1 "><p id="p15132185775510"><a name="p15132185775510"></a><a name="p15132185775510"></a>usb_srv_client.h</p>
<p id="p18132157175510"><a name="p18132157175510"></a><a name="p18132157175510"></a></p>
<p id="p2133757135510"><a name="p2133757135510"></a><a name="p2133757135510"></a></p>
</td>
<td class="cellrowborder" valign="top" width="66.36663666366637%" headers="mcps1.2.4.1.1 "><p id="p1213365714550"><a name="p1213365714550"></a><a name="p1213365714550"></a>int32_t OpenDevice(const UsbDevice &device, USBDevicePipe &pip);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p201331557185512"><a name="p201331557185512"></a><a name="p201331557185512"></a>打开USB设备，建立连接</p>
</td>
</tr>
<tr id="row171331657185514"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p913305715553"><a name="p913305715553"></a><a name="p913305715553"></a>int32_t HasRight(std::string deviceName);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p161332570553"><a name="p161332570553"></a><a name="p161332570553"></a>判断是否有权访问设备</p>
</td>
</tr>
<tr id="row41331557165518"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p6133145713559"><a name="p6133145713559"></a><a name="p6133145713559"></a>int32_t RequestRight(std::string deviceName);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p131331557175510"><a name="p131331557175510"></a><a name="p131331557175510"></a>请求给定软件包的临时权限以访问设备</p>
</td>
</tr>
<tr id="row77021769584"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p77031566584"><a name="p77031566584"></a><a name="p77031566584"></a>int32_t GetDevices(std::vector<UsbDevice> &deviceList);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1470315695811"><a name="p1470315695811"></a><a name="p1470315695811"></a>获取USB设备列表</p>
</td>
</tr>
<tr id="row71857914585"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p1318619155811"><a name="p1318619155811"></a><a name="p1318619155811"></a>int32_t ClaimInterface(USBDevicePipe &pip, const UsbInterface &interface, bool force);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1186597589"><a name="p1186597589"></a><a name="p1186597589"></a>打开接口，并申明独占接口，必须在数据传输前执行</p>
</td>
</tr>
<tr id="row18831119115815"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p48323975814"><a name="p48323975814"></a><a name="p48323975814"></a>int32_t ReleaseInterface(USBDevicePipe &pip, const UsbInterface &interface);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p15832129135813"><a name="p15832129135813"></a><a name="p15832129135813"></a>关闭接口，释放接口的占用，在停止数据传输后执行</p>
</td>
</tr>
<tr id="row71857914585"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p1318619155811"><a name="p1318619155811"></a><a name="p1318619155811"></a>int32_t BulkTransfer(USBDevicePipe &pip, const USBEndpoint &endpoint, std::vector<uint8_t> &vdata, int32_t timeout);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1186597589"><a name="p1186597589"></a><a name="p1186597589"></a>在给定端点上执行批量数据传输， 返回读取或发送的数据长度，通过端点方向确定读取或发送数据</p>
</td>
</tr>
<tr id="row18831119115815"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p48323975814"><a name="p48323975814"></a><a name="p48323975814"></a>int32_t ControlTransfer(USBDevicePipe &pip, const UsbCtrlTransfer &ctrl, std::vector<uint8_t> &vdata);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p15832129135813"><a name="p15832129135813"></a><a name="p15832129135813"></a>对此设备执行端点零的控制事务，传输方向由请求类型决定</p>
</td>
</tr>
<tr id="row71857914585"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p1318619155811"><a name="p1318619155811"></a><a name="p1318619155811"></a>int32_t SetConfiguration(USBDevicePipe &pip, const USBConfig &config);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1186597589"><a name="p1186597589"></a><a name="p1186597589"></a>设置设备当前使用的配置，通过配置值进行指定</p>
</td>
</tr>
<tr id="row18831119115815"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p48323975814"><a name="p48323975814"></a><a name="p48323975814"></a>int32_t SetInterface(USBDevicePipe &pipe, const UsbInterface &interface);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p15832129135813"><a name="p15832129135813"></a><a name="p15832129135813"></a>设置指定接口的备选设置，用于在具有相同ID但不同备用设置的两个接口之间进行选择</p>
</td>
</tr>
<tr id="row71857914585"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p1318619155811"><a name="p1318619155811"></a><a name="p1318619155811"></a>int32_t GetRawDescriptors(std::vector<uint8_t> &vdata);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1186597589"><a name="p1186597589"></a><a name="p1186597589"></a>获取原始的USB描述符</p>
</td>
</tr>
<tr id="row18831119115815"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p48323975814"><a name="p48323975814"></a><a name="p48323975814"></a>int32_t GetFileDescriptor();</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p15832129135813"><a name="p15832129135813"></a><a name="p15832129135813"></a>获取文件描述符</p>
</td>
</tr>
<tr id="row71857914585"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p1318619155811"><a name="p1318619155811"></a><a name="p1318619155811"></a>bool Close(const USBDevicePipe &pip);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1186597589"><a name="p1186597589"></a><a name="p1186597589"></a>关闭设备，释放与设备相关的所有系统资源</p>
</td>
</tr>
<tr id="row18831119115815"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p48323975814"><a name="p48323975814"></a><a name="p48323975814"></a>int32_t PipeRequestWait(USBDevicePipe &pip, int64_t timeout, UsbRequest &req);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p15832129135813"><a name="p15832129135813"></a><a name="p15832129135813"></a>获取异步传输结果</p>
</td>
</tr>
<tr id="row71857914585"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p1318619155811"><a name="p1318619155811"></a><a name="p1318619155811"></a>int32_t RequestInitialize(UsbRequest &request);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1186597589"><a name="p1186597589"></a><a name="p1186597589"></a>初始化异步数据传输request</p>
</td>
</tr>
<tr id="row18831119115815"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p48323975814"><a name="p48323975814"></a><a name="p48323975814"></a>int32_t RequestFree(UsbRequest &request);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p15832129135813"><a name="p15832129135813"></a><a name="p15832129135813"></a>释放异步数据传输request</p>
</td>
</tr>
<tr id="row1513316577554"><td class="cellrowborder" rowspan="27" valign="top" headers="mcps1.2.4.1.1 ">
<td class="cellrowborder" valign="top" width="66.36663666366637%" headers="mcps1.2.4.1.2 "><p id="p105259109581"><a name="p105259109581"></a><a name="p105259109581"></a>int32_t RequestAbort(UsbRequest &request);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.3 "><p id="p752531095814"><a name="p752531095814"></a><a name="p752531095814"></a>取消待处理的数据请求</p>
</td>
</tr>
<tr id="row172902161193"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p16290141681918"><a name="p16290141681918"></a><a name="p16290141681918"></a>int32_t RequestQueue(UsbRequest &request);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1929141611198"><a name="p1929141611198"></a><a name="p1929141611198"></a>将指定的端点进行异步数据发送或者接收请求，数据传输方向由端点方向决定</p>
</td>
</tr>
<tr id="row172902161193"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p16290141681918"><a name="p16290141681918"></a><a name="p16290141681918"></a>int32_t BulkRequstDataSize(const UsbDev &dev, const UsbPipe &pipe, uint32_t &length);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1929141611198"><a name="p1929141611198"></a><a name="p1929141611198"></a>异步批量读取数据，传输大量数据时使用</p>
</td>
</tr>
<tr id="row172902161193"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p16290141681918"><a name="p16290141681918"></a><a name="p16290141681918"></a>int32_t BulkReadData(const UsbDev &dev, const UsbPipe &pipe, std::vector<uint8_t> &data);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1929141611198"><a name="p1929141611198"></a><a name="p1929141611198"></a>与BulkReadData配合使用，获取读取结果</p>
</td>
</tr>
<tr id="row172902161193"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p16290141681918"><a name="p16290141681918"></a><a name="p16290141681918"></a>int32_t BulkWriteData(const UsbDev &dev, const UsbPipe &pipe, const std::vector<uint8_t> &data);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1929141611198"><a name="p1929141611198"></a><a name="p1929141611198"></a>异步批量写数据，传输大量数据时使用</p>
</td>
</tr>
<tr id="row172902161193"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p16290141681918"><a name="p16290141681918"></a><a name="p16290141681918"></a>int32_t BulkGetWriteCompleteLength(const UsbDev &dev, const UsbPipe &pipe, uint32_t &length);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1929141611198"><a name="p1929141611198"></a><a name="p1929141611198"></a>与BulkWriteData配合使用，获取写入状态，由length描述</p>
</td>
</tr>
</tbody>
</table>

- ### Device部分<a name="section83365421669"></a>

<a name="table1513255710559"></a>
<table><thead align="left"><tr id="row171321857155517"><th class="cellrowborder" valign="top" width="10.721072107210723%" id="mcps1.2.4.1.1"><p id="p6132957115511"><a name="p6132957115511"></a><a name="p6132957115511"></a>头文件</p>
</th>
<th class="cellrowborder" valign="top" width="66.36663666366637%" id="mcps1.2.4.1.2"><p id="p14132125715552"><a name="p14132125715552"></a><a name="p14132125715552"></a>接口名称</p>
</th>
<th class="cellrowborder" valign="top" width="22.912291229122914%" id="mcps1.2.4.1.3"><p id="p18132205755516"><a name="p18132205755516"></a><a name="p18132205755516"></a>功能描述</p>
</th>
</tr>
</thead>
<tbody><tr id="row13132357165514"><td class="cellrowborder" rowspan="16" valign="top" width="10.721072107210723%" headers="mcps1.2.4.1.1 "><p id="p15132185775510"><a name="p15132185775510"></a><a name="p15132185775510"></a>usb_srv_client.h</p>
<p id="p18132157175510"><a name="p18132157175510"></a><a name="p18132157175510"></a></p>
<p id="p2133757135510"><a name="p2133757135510"></a><a name="p2133757135510"></a></p>
</td>
<td class="cellrowborder" valign="top" width="66.36663666366637%" headers="mcps1.2.4.1.1 "><p id="p1213365714550"><a name="p1213365714550"></a><a name="p1213365714550"></a>int32_t GetCurrentFunctions(int32_t &funcs);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p201331557185512"><a name="p201331557185512"></a><a name="p201331557185512"></a>获取设备模式下的当前USB功能列表的数字组合掩码</p>
</td>
</tr>
<tr id="row171331657185514"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p913305715553"><a name="p913305715553"></a><a name="p913305715553"></a>int32_t SetCurrentFunctions(int32_t funcs);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p161332570553"><a name="p161332570553"></a><a name="p161332570553"></a>在设备模式下设置当前的USB功能列表</p>
</td>
</tr>
<tr id="row41331557165518"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p6133145713559"><a name="p6133145713559"></a><a name="p6133145713559"></a>int32_t UsbFunctionsFromString(std::string funcs);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p131331557175510"><a name="p131331557175510"></a><a name="p131331557175510"></a>将给定的功能列表描述字符串转换为功能列表的数字组合掩码</p>
</td>
</tr>
<tr id="row77021769584"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p77031566584"><a name="p77031566584"></a><a name="p77031566584"></a>std::string UsbFunctionsToString(int32_t funcs);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p1470315695811"><a name="p1470315695811"></a><a name="p1470315695811"></a>将给定的功能列表的数字组合掩码转换为功能列表描述字符串</p>
</td>
</tr>
</tbody>
</table>

- ### Port部分<a name="section83365421670"></a>

<a name="table1513255710559"></a>
<table><thead align="left"><tr id="row171321857155517"><th class="cellrowborder" valign="top" width="10.721072107210723%" id="mcps1.2.4.1.1"><p id="p6132957115511"><a name="p6132957115511"></a><a name="p6132957115511"></a>头文件</p>
</th>
<th class="cellrowborder" valign="top" width="66.36663666366637%" id="mcps1.2.4.1.2"><p id="p14132125715552"><a name="p14132125715552"></a><a name="p14132125715552"></a>接口名称</p>
</th>
<th class="cellrowborder" valign="top" width="22.912291229122914%" id="mcps1.2.4.1.3"><p id="p18132205755516"><a name="p18132205755516"></a><a name="p18132205755516"></a>功能描述</p>
</th>
</tr>
</thead>
<tbody><tr id="row13132357165514"><td class="cellrowborder" rowspan="16" valign="top" width="10.721072107210723%" headers="mcps1.2.4.1.1 "><p id="p15132185775510"><a name="p15132185775510"></a><a name="p15132185775510"></a>usb_srv_client.h</p>
<p id="p18132157175510"><a name="p18132157175510"></a><a name="p18132157175510"></a></p>
<p id="p2133757135510"><a name="p2133757135510"></a><a name="p2133757135510"></a></p>
</td>
<td class="cellrowborder" valign="top" width="66.36663666366637%" headers="mcps1.2.4.1.1 "><p id="p1213365714550"><a name="p1213365714550"></a><a name="p1213365714550"></a>int32_t GetSupportedModes(int32_t portId, int32_t &supportedModes);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p201331557185512"><a name="p201331557185512"></a><a name="p201331557185512"></a>获取指定的端口支持的模式列表的组合掩码</p>
</td>
</tr>
<tr id="row171331657185514"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p913305715553"><a name="p913305715553"></a><a name="p913305715553"></a>int32_t SetPortRole(int32_t portId, int32_t powerRole, int32_t dataRole);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p161332570553"><a name="p161332570553"></a><a name="p161332570553"></a>设置指定的端口支持的角色模式，包含充电角色、数据传输角色</p>
</td>
</tr>
<tr id="row41331557165518"><td class="cellrowborder" valign="top" headers="mcps1.2.4.1.1 "><p id="p6133145713559"><a name="p6133145713559"></a><a name="p6133145713559"></a>int32_t GetPorts(std::vector<UsbPort> &usbPorts);</p>
</td>
<td class="cellrowborder" valign="top" headers="mcps1.2.4.1.2 "><p id="p131331557175510"><a name="p131331557175510"></a><a name="p131331557175510"></a>获取物理USB端口描述信息列表</p>
</td>
</tr>
</tbody>
</table>