[PATCH v2 04/11] rust: usb: use `Option<&IdInfo>` for device ID info

[Gary Guo <gary@garyguo.net>]

It is possible that ID without driver_data will be passed to the driver,
e.g. `new_id` is used to dynamically create a new ID without data.
Therefore, the driver must be able to handle the case where `driver_data`
is 0. Thus, update the `probe` functions to get `Option`.

The current code cannot tell if the info does not exist or is the first
entry; however this will be achievable once the code is updated to use a
`&'static IdInfo` pointer instead of indices.

Signed-off-by: Gary Guo <gary@garyguo.net>
---
 rust/kernel/usb.rs              | 6 +++---
 samples/rust/rust_driver_usb.rs | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/rust/kernel/usb.rs b/rust/kernel/usb.rs
index 7aff0c82d0af..6750a49e466b 100644
--- a/rust/kernel/usb.rs
+++ b/rust/kernel/usb.rs
@@ -90,7 +90,7 @@ extern "C" fn probe_callback(
             let id = unsafe { &*id.cast::<DeviceId>() };
 
             let info = T::ID_TABLE.info(id.index());
-            let data = T::probe(intf, id, info);
+            let data = T::probe(intf, id, Some(info));
 
             let dev: &device::Device<device::CoreInternal<'_>> = intf.as_ref();
             dev.set_drvdata(data)?;
@@ -293,7 +293,7 @@ macro_rules! usb_device_table {
 ///     fn probe<'bound>(
 ///         _interface: &'bound usb::Interface<Core<'_>>,
 ///         _id: &usb::DeviceId,
-///         _info: &'bound Self::IdInfo,
+///         _info: Option<&'bound Self::IdInfo>,
 ///     ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound {
 ///         Err(ENODEV)
 ///     }
@@ -322,7 +322,7 @@ pub trait Driver {
     fn probe<'bound>(
         interface: &'bound Interface<device::Core<'_>>,
         id: &DeviceId,
-        id_info: &'bound Self::IdInfo,
+        id_info: Option<&'bound Self::IdInfo>,
     ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound;
 
     /// USB driver disconnect.
diff --git a/samples/rust/rust_driver_usb.rs b/samples/rust/rust_driver_usb.rs
index 02bd5085f9bc..176ef625ed75 100644
--- a/samples/rust/rust_driver_usb.rs
+++ b/samples/rust/rust_driver_usb.rs
@@ -32,7 +32,7 @@ impl usb::Driver for SampleDriver {
     fn probe<'bound>(
         intf: &'bound usb::Interface<Core<'_>>,
         _id: &usb::DeviceId,
-        _info: &'bound Self::IdInfo,
+        _info: Option<&'bound Self::IdInfo>,
     ) -> impl PinInit<Self, Error> + 'bound {
         let dev: &device::Device<Core<'_>> = intf.as_ref();
         dev_info!(dev, "Rust USB driver sample probed\n");

-- 
2.54.0