fuchsia.hardware.radar

PROTOCOLS

RadarBurstReader

Defined in fuchsia.hardware.radar/radar.fidl

GetBurstSize

Returns the size in bytes of each burst reported by this driver. Clients should use this size to create VMOs to be registered by the driver.

response burst_size the size of each radar burst in bytes.

Request

<EMPTY>

Response

Name	Type
`burst_size`	`uint32`

OnBurst

Returns the ID of a VMO containing a single burst, the time the burst was received. Ownership of the VMO must be returned to the driver by calling UnlockVmo(), and won't be written by the driver until then. See the doc for the burst format specification.

The driver will drop bursts if there are no unlocked VMOs. This also provides flow control for the number of events in flight. When a burst is received and no VMOs are unlocked, OnBurst() will be called with OUT_OF_VMOS set as the error. OnBurst will not be called again until at least one VMO has been unlocked.

request burst the ID of a VMO containing the burst, as well as the time the burst was received.

error one of the following StatusCode values:

`OUT_OF_VMOS`: No unlocked VMOs were available to hold the burst.

    The driver will wait for at least one VMO to become available

    before sending more events to this client.

`SENSOR_TIMEOUT`: The driver could not drain the sensor FIFO

```
    quickly enough.
```

`SENSOR_ERROR`: An unspecified driver or sensor error occurred

```
    when trying to read the burst.
```

Response

Name	Type
`result`	`RadarBurstReader_OnBurst_Result`

RegisterVmos

Registers the VMOs for future use and associates them with vmo_ids, which can be used with UnregisterVmos() and OnBurst(). vmos will be mapped by the driver using ZX_VM_PERM_WRITE. The client should only read registered VMOs that are sent via OnBurst(). The size of vmo is assumed to be at least the burst size, and the sizes of vmo_ids and vmos must be the same.

request vmo_ids the ID numbers to associate with each VMO.
request vmos the VMO handles corresponding to each ID.

error one of the following StatusCode values:

`INVALID_ARGS`: `vmo_ids` and `vmos` were of different sizes.

`VMO_BAD_HANDLE`: A handle in `vmos` was invalid.

`VMO_ALREADY_REGISTERED`: An ID in `vmo_ids` was already

```
    registered.
```

`VMO_ACCESS_DENIED`: A VMO in `vmos` could not be mapped due to

```
    insufficient permissions.
```

`VMO_TOO_SMALL`: A VMO in `vmos` was smaller than the burst size.

Request

Name	Type
`vmo_ids`	`vector<uint32>[300]`
`vmos`	`vector<vmo>[300]`

Response

Name	Type
`result`	`RadarBurstReader_RegisterVmos_Result`

StartBursts

Tells the driver to start sending bursts via OnBurst().

Request

<EMPTY>

StopBursts

Tells the driver to stop sending bursts via OnBurst(). If all clients call StopBursts() then the driver may choose to stop its worker thread. The driver may wait for a single burst read to complete, but will not access any of the client’s VMOs or call its observer after replying.

Note that already inflight OnBurst() bursts may still be received by the client.

Request

<EMPTY>

Response

<EMPTY>

UnlockVmo

Signals to the driver that the client is no longer reading the VMO. The client must not access the VMO after calling this.

request vmo_id the ID of the VMO to return to the driver.

Request

Name	Type
`vmo_id`	`uint32`

UnregisterVmos

Removes the associations with the given VMO IDs and returns the VMOs to the client. The driver will not send any more OnBurst() events with these VMO IDs after replying, however the client may still receive bursts with these IDs if they were in flight during this call. The driver must return all of the requested VMOs, or return an error. In case of an error, the driver may have unregistered some or all of the requested VMOs.

request vmo_ids the IDs of the VMOs to unregister and return.

response vmos the VMO handles corresponding to vmo_ids.

error one of the following StatusCode values:
```
`INVALID_ARGS`: `vmo_ids` was too big.
```

`VMO_NOT_FOUND`: An ID in `vmo_ids` was not registered.

Request

Name	Type
`vmo_ids`	`vector<uint32>[300]`

Response

Name	Type
`result`	`RadarBurstReader_UnregisterVmos_Result`

RadarBurstReaderProvider

Defined in fuchsia.hardware.radar/radar.fidl

The main protocol implemented by radar drivers. Clients use this protocol to establish a RadarBurstReader connection with the driver.

Connect

request server the RadarBurstReader server end for the driver to bind to.

error one of the following StatusCode values: BIND_ERROR: An error was encountered while trying to bind to the provided server channel. ALREADY_BOUND: Another client has already established a RadarBurstReader connection with the driver.

Request

Name	Type
`server`	`request<RadarBurstReader>`

Response

Name	Type
`result`	`RadarBurstReaderProvider_Connect_Result`

STRUCTS

Burst

Defined in fuchsia.hardware.radar/radar.fidl

Field	Type	Description	Default
`vmo_id`	`uint32`		No default
`timestamp`	`zx/time`		No default

RadarBurstReaderProvider_Connect_Response

Defined in fuchsia.hardware.radar/radar.fidl

<EMPTY>

RadarBurstReader_OnBurst_Response

Defined in fuchsia.hardware.radar/radar.fidl

Field	Type	Description	Default
`burst`	`Burst`		No default

RadarBurstReader_RegisterVmos_Response

Defined in fuchsia.hardware.radar/radar.fidl

<EMPTY>

RadarBurstReader_UnregisterVmos_Response resource

Defined in fuchsia.hardware.radar/radar.fidl

Field	Type	Description	Default
`vmos`	`vector<vmo>[300]`		No default

ENUMS

StatusCode strict

Type: uint32

Defined in fuchsia.hardware.radar/radar.fidl

Name	Value	Description
`UNSPECIFIED`	`0`	An unspecified error occurred (generally should not be used).
`SUCCESS`	`1`	The request completed successfully.
`ALREADY_BOUND`	`2`	`Connect()` was called but the driver is busy handling another client. The other client will have to close its channel for the driver to become available again.
`BIND_ERROR`	`3`	`Connect()` encountered an error trying to bind to the provided server channel.
`INVALID_ARGS`	`4`	The vectors passed to `RegisterVmos()` did not have the same size.
`VMO_BAD_HANDLE`	`5`	A VMO handle was invalid.
`VMO_ALREADY_REGISTERED`	`6`	A VMO was already registered with this ID.
`VMO_NOT_FOUND`	`7`	No registered VMO was found for the given ID.
`VMO_ACCESS_DENIED`	`8`	A client VMO could not be written to or mapped due to insufficient permissions.
`VMO_TOO_SMALL`	`9`	A client VMO was smaller than the burst size (see `GetBurstSize()`).
`OUT_OF_VMOS`	`10`	A burst was received, but no unlocked VMOs are available.
`SENSOR_TIMEOUT`	`11`	A burst was not received within the expected window.
`SENSOR_ERROR`	`12`	An unspecified driver or sensor error was encountered.

UNIONS

RadarBurstReaderProvider_Connect_Result strict

Defined in fuchsia.hardware.radar/radar.fidl

Ordinal
Variant	Type	Description
1	`response`	`RadarBurstReaderProvider_Connect_Response`
2	`err`	`StatusCode`

RadarBurstReader_OnBurst_Result strict

Defined in fuchsia.hardware.radar/radar.fidl

Ordinal
Variant	Type	Description
1	`response`	`RadarBurstReader_OnBurst_Response`
2	`err`	`StatusCode`

RadarBurstReader_RegisterVmos_Result strict

Defined in fuchsia.hardware.radar/radar.fidl

Ordinal
Variant	Type	Description
1	`response`	`RadarBurstReader_RegisterVmos_Response`
2	`err`	`StatusCode`

RadarBurstReader_UnregisterVmos_Result strict resource

Defined in fuchsia.hardware.radar/radar.fidl

Ordinal
Variant	Type	Description
1	`response`	`RadarBurstReader_UnregisterVmos_Response`
2	`err`	`StatusCode`

CONSTANTS

Name	Value	Type	Description
VMO_VECTOR_MAX_COUNT	`300`	`uint32`	Arbitrary limit on the number of VMOs in one call to `RegisterVmos()` or `UnregisterVmos()`; enough for ten seconds of radar data for the existing driver.