_driver_rustc/
lib.rs

1// Copyright 2024 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use fdf_component::{
6    driver_register, Driver, DriverContext, Node, NodeBuilder, ZirconServiceOffer,
7};
8use fidl_fuchsia_hardware_i2c as i2c;
9use fuchsia_component::server::ServiceFs;
10use futures::{StreamExt, TryStreamExt};
11use log::info;
12use zx::Status;
13
14/// The implementation of our driver will live in this object, which implements [`Driver`].
15#[allow(unused)]
16struct ZirconParentDriver {
17    /// The [`NodeProxy`] is our handle to the node we bound to. We need to keep this handle
18    /// open to keep the node around.
19    node: Node,
20}
21
22// This creates the exported driver registration structures that allow the driver host to
23// find and run the start and stop methods on our `ZirconParentDriver`.
24driver_register!(ZirconParentDriver);
25
26async fn i2c_server(mut service: i2c::DeviceRequestStream) {
27    use i2c::DeviceRequest::*;
28    while let Some(req) = service.try_next().await.unwrap() {
29        match req {
30            Transfer { responder, .. } => responder.send(Ok(&[vec![0x1u8, 0x2, 0x3]])),
31            GetName { responder } => responder.send(Ok("rust i2c server")),
32        }
33        .unwrap();
34    }
35}
36
37impl Driver for ZirconParentDriver {
38    const NAME: &str = "zircon_parent_rust_driver";
39
40    async fn start(mut context: DriverContext) -> Result<Self, Status> {
41        info!("Binding node client. Every driver needs to do this for the driver to be considered loaded.");
42        let node = context.take_node()?;
43
44        info!("Offering an i2c service in the outgoing directory");
45        let mut outgoing = ServiceFs::new();
46        let offer = ZirconServiceOffer::new()
47            .add_default_named(&mut outgoing, "default", |i| {
48                // Since we're only acting on one kind of service here, we just unwrap it and that's
49                // the type of our handler. If you were handling more services, you would usually
50                // wrap it in an enum containing one discriminant per protocol handled.
51                let i2c::ServiceRequest::Device(service) = i;
52                service
53            })
54            .build();
55
56        info!("Creating child node with a service offer");
57        let child_node = NodeBuilder::new("zircon_transport_rust_child").add_offer(offer).build();
58        node.add_child(child_node).await?;
59
60        context.serve_outgoing(&mut outgoing)?;
61
62        fuchsia_async::Task::spawn(async move {
63            outgoing.for_each_concurrent(None, i2c_server).await;
64        })
65        .detach();
66
67        Ok(Self { node })
68    }
69
70    async fn stop(&self) {
71        info!(
72            "ZirconParentDriver::stop() was invoked. Use this function to do any cleanup needed."
73        );
74    }
75}
_driver_rustc/lib.rs

_driver_rustc/
lib.rs
