PROTOCOLS
Device
Defined in fuchsia.hardware.usb.device/usb-device.fidl
GetConfiguration
Returns the device's current configuration.
Request
<EMPTY>
Response
| Name | Type |
|---|---|
configuration |
uint8
|
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]
|
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
|
GetDeviceDescriptor
Returns the device's USB device descriptor.
Request
<EMPTY>
Response
| Name | Type |
|---|---|
desc |
uint8[18]
|
GetDeviceId
Returns an implementation specific device ID for a USB device. For informational purposes only.
Request
<EMPTY>
Response
| Name | Type |
|---|---|
device_id |
uint32
|
GetDeviceSpeed
Returns the speed of the USB device as a usb_speed_t value.
Request
<EMPTY>
Response
| Name | Type |
|---|---|
speed |
uint32
|
GetHubDeviceId
Returns the implementation specific device ID for the hub that a USB device is connected to. For informational purposes only.
Request
<EMPTY>
Response
| Name | Type |
|---|---|
hub_device_id |
uint32
|
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
|
SetConfiguration
Sets the device's current configuration.
Request
| Name | Type |
|---|---|
configuration |
uint8
|
Response
| Name | Type |
|---|---|
s |
zx/status
|
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
|
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 |