Introduction to Driver Development Kit

Empowered by the C-API solution, Driver Development Kit provides easy-to-use, secure, and diversified ArkTs-API and C APIs to elevate your experience in developing peripheral drivers, which bring ultimate plug-and-play experience to users.

When to Use

With Driver Development Kit, you can develop dedicated or extended peripheral drivers in an efficient and secure manner.

Develop drivers of dedicated

peripherals for bank counters, enterprise office, and medical detection, such as high-speed document scanners, ID card scanners, fingerprint scanners, and blood oxygen and blood glucose meters.
Develop enhanced functions of non-standard peripherals,

such as customizing handwriting pad shortcut keys, setting the pressure sensing/drawing area, setting extended enhancement capabilities, setting the mouse lighting effect, customizing mouse extended buttons, and setting DPI and X and Y axes.

Typical Use Cases

You can develop advanced peripheral functions to meet user requirements.
The extended driver framework supports lifecycle management of peripheral drivers and provides APIs for querying and binding peripheral devices.

Basic Concepts

Peripheral driver client: basic UI-based driver, which is used to query and bind drivers, and customize the communication mode and data processing mode.
Peripheral driver: basic UI-free driver, which is the dedicated peripheral driver or enhanced peripheral driver developed based on the DDK.
External Device Manager: performs lifecycle management of peripheral devices and driver packages.
Bundle Manager Service (BMS): manages application installation, uninstallation, and data on the system.
Ability Manager Service (AMS): starts and stops DriverExtensionAbility.

Implementation Principles

The HDF extended driver framework provides unified APIs for you to leverage the DDK capabilities for user-mode peripheral driver development.

External Device Manager, the core service of user-mode peripheral management, performs lifecycle management of peripherals and peripheral drivers. In addition, standard ArkTS APIs are provided to query, bind, and unbind peripherals.

Peripheral Driver Architecture

Figure 1 Peripheral driver working mechanism

driverExtension

Operation Process

Figure 2 shows the process for matching a peripheral driver client with a peripheral driver when a peripheral is connected.

Figure 2 Process for matching a peripheral driver client with a peripheral driver

timeSeries1

Figure 3 shows the process for binding the peripheral driver client with a peripheral driver.

Figure 3 Process of binding the peripheral driver client with a peripheral driver

timeSeries2

Notes and Constraints

To call the ArkTs or C APIs provided by Driver Development Kit, you need to apply for specified permissions.

The following table lists the required permissions.

API Type	DDK Type	Permission
ArkTs-API	NA	ohos.permission.ACCESS_EXTENSIONAL_DEVICE_DRIVER
C-API	USB DDK	ohos.permission.ACCESS_DDK_USB
C-API	HID DDK	ohos.permission.ACCESS_DDK_HID
C-API	USB Serial DDK	ohos.permission.ACCESS_DDK_USB_SERIAL
C-API	SCSI Peripheral DDK	ohos.permission.ACCESS_DDK_SCSI_PERIPHERAL

Associated Modules

The following table lists the associated modules you may use during development of peripheral drivers.

Name	Description
PerformanceAnalysisKit	Introduces {hilog} for log printing.
BasicServicesKit	Introduces {BusinessError} to capture error information.
IPCKit	Introduces {rpc} to implement inter-process communication between the driver and the client.
AbilityKit	Introduces {want} for lifecycle management.