Gadget Driver

最新推荐文章于 2021-05-06 16:36:49 发布

最新推荐文章于 2021-05-06 16:36:49 发布 · 84 阅读

GadgetDriver在嵌入式环境中通过控制器驱动调用实现硬件中立的USB功能，配置用于特定控制器的端点，并处理设置请求、配置和字符串描述符、端点生命周期事件和数据传输。

Gadget Driver

The lower boundary of this driver implements hardware-neutralUSB functions, using calls to the controller driver.Because such hardware varies widely in capabilities and restrictions,and is used in embedded environments where space is at a premium,the gadget driver is often configured at compile timeto work with endpoints supported by one particular controller.Gadget drivers may be portable to several different controllers,using conditional compilation.(Recent kernels substantially simplify the work involved insupporting new hardware, by autoconfiguringendpoints automatically for many bulk-oriented drivers.)Gadget driver responsibilities include:

handling setup requests (ep0 protocol responses)possibly including class-specific functionality
returning configuration and string descriptors
(re)setting configurations and interfacealtsettings, including enabling and configuring endpoints
handling life cycle events, such as managingbindings to hardware,USB suspend/resume, remote wakeup,and disconnection from the USB host.
managing IN and OUT transfers on all currentlyenabled endpoints

Such drivers may be modules of proprietary code, althoughthat approach is discouraged in the Linux community.