fuchsia.hardware.usb.device

PROTOCOLS

Device

Defined in fuchsia.hardware.usb.device/usb-device.fidl

GetDeviceSpeed

Returns the speed of the USB device as a usb_speed_t value.

Request

Name	Type

Response

Name	Type
speed	uint32

GetDeviceDescriptor

Returns the device's USB device descriptor.

Request

Name	Type

Response

Name	Type
desc	uint8[18]

GetConfigurationDescriptorSize

Returns the total size of the USB configuration descriptor for the given configuration.

Request

Name	Type
config	uint8

Response

Name	Type
s	zx/status
size	uint16

GetConfigurationDescriptor

Returns the device's USB configuration descriptor for the given configuration.

Request

Name	Type
config	uint8

Response

Name	Type
s	zx/status
desc	vector<uint8>[65536]

GetStringDescriptor

Fetches a string descriptor from the USB device.

desc_id : The ID of the string descriptor to fetch, or 0 to fetch the language table instead.

lang_id : The language ID of the string descriptor to fetch. If no matching language ID is present in the device's language ID table, the first entry of the language ID table will be substituted. actual_lang_id : The actual language ID of the string fetched, or 0 for the language ID table.

The worst case size for the payload of a language ID table should be 252 bytes, meaning that a 256 byte buffer should always be enough to hold any language ID table.

The worst case size for a UTF-8 encoded string descriptor payload should be 378 bytes (126 UTF-16 code units with a worst case expansion factor of 3)

Request

Name	Type
desc_id	uint8
lang_id	uint16

Response

Name	Type
s	zx/status
desc	string[384]
actual_lang_id	uint16

SetInterface

Selects an alternate setting for an interface on a USB device.

Request

Name	Type
interface_number	uint8
alt_setting	uint8

Response

Name	Type
s	zx/status

GetDeviceId

Returns an implementation specific device ID for a USB device. For informational purposes only.

Request

Name	Type

Response

Name	Type
device_id	uint32

GetHubDeviceId

Returns the implementation specific device ID for the hub that a USB device is connected to. For informational purposes only.

Request

Name	Type

Response

Name	Type
hub_device_id	uint32

GetConfiguration

Returns the device's current configuration.

Request

Name	Type

Response

Name	Type
configuration	uint8

SetConfiguration

Sets the device's current configuration.

Request

Name	Type
configuration	uint8

Response

Name	Type
s	zx/status

STRUCTS

CONSTANTS

Name	Value	Type	Description
DEVICE_DESC_SIZE	18	uint32	sizeof(usb_device_descriptor_t)
MAX_CONFIG_DESC_SIZE	65536	uint32	UINT16_MAX
MAX_STRING_DESC_SIZE	384	uint32	See GetStringDescriptor description below