[PATCH 2/2] samples: rust: add a USB driver sample

[Daniel Almeida <daniel.almeida@collabora.com>]

In light of the newly-added Rust abstractions for USB devices and
drivers, add a sample USB rust driver that serves both to showcase what
is currently supported, as well as be the only user of the USB
abstractions for now.

Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
---
 samples/rust/Kconfig            | 11 ++++++++++
 samples/rust/Makefile           |  1 +
 samples/rust/rust_driver_usb.rs | 47 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+)

diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
index 7f7371a004ee0a8f67dca99c836596709a70c4fa..fb222f93014c921b27a8a9a4293e90a2532faa82 100644
--- a/samples/rust/Kconfig
+++ b/samples/rust/Kconfig
@@ -83,6 +83,17 @@ config SAMPLE_RUST_DRIVER_PLATFORM
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_DRIVER_USB
+	tristate "USB Driver"
+	depends on USB
+	help
+	  This option builds the Rust USB driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_usb.
+
+	  If unsure, say N.
+
 config SAMPLE_RUST_DRIVER_FAUX
 	tristate "Faux Driver"
 	help
diff --git a/samples/rust/Makefile b/samples/rust/Makefile
index bd2faad63b4f3befe7d1ed5139fe25c7a8b6d7f6..4e7df8a5cd277d101920c4b89a3ac6648b372b28 100644
--- a/samples/rust/Makefile
+++ b/samples/rust/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_SAMPLE_RUST_PRINT)			+= rust_print.o
 obj-$(CONFIG_SAMPLE_RUST_DMA)			+= rust_dma.o
 obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI)		+= rust_driver_pci.o
 obj-$(CONFIG_SAMPLE_RUST_DRIVER_PLATFORM)	+= rust_driver_platform.o
+obj-$(CONFIG_SAMPLE_RUST_DRIVER_USB)		+= rust_driver_usb.o
 obj-$(CONFIG_SAMPLE_RUST_DRIVER_FAUX)		+= rust_driver_faux.o
 obj-$(CONFIG_SAMPLE_RUST_DRIVER_AUXILIARY)	+= rust_driver_auxiliary.o
 obj-$(CONFIG_SAMPLE_RUST_CONFIGFS)		+= rust_configfs.o
diff --git a/samples/rust/rust_driver_usb.rs b/samples/rust/rust_driver_usb.rs
new file mode 100644
index 0000000000000000000000000000000000000000..5c396f421de7f972985e57af48e8a9da0c558973
--- /dev/null
+++ b/samples/rust/rust_driver_usb.rs
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPDX-FileCopyrightText: Copyright (C) 2025 Collabora Ltd.
+
+//! Rust USB driver sample.
+
+use kernel::{device, device::Core, prelude::*, sync::aref::ARef, usb};
+
+struct SampleDriver {
+    _intf: ARef<usb::Interface>,
+}
+
+kernel::usb_device_table!(
+    USB_TABLE,
+    MODULE_USB_TABLE,
+    <SampleDriver as usb::Driver>::IdInfo,
+    [(usb::DeviceId::from_id(0x1234, 0x5678), ()),]
+);
+
+impl usb::Driver for SampleDriver {
+    type IdInfo = ();
+    const ID_TABLE: usb::IdTable<Self::IdInfo> = &USB_TABLE;
+
+    fn probe(
+        intf: &usb::Interface<Core>,
+        _id: &usb::DeviceId,
+        _info: &Self::IdInfo,
+    ) -> Result<Pin<KBox<Self>>> {
+        let dev: &device::Device<Core> = intf.as_ref();
+        dev_info!(dev, "Rust USB driver sample probed\n");
+
+        let drvdata = KBox::new(Self { _intf: intf.into() }, GFP_KERNEL)?;
+        Ok(drvdata.into())
+    }
+
+    fn disconnect(intf: &usb::Interface<Core>, _data: Pin<&Self>) {
+        let dev: &device::Device<Core> = intf.as_ref();
+        dev_info!(dev, "Rust USB driver sample disconnected\n");
+    }
+}
+
+kernel::module_usb_driver! {
+    type: SampleDriver,
+    name: "rust_driver_usb",
+    authors: ["Daniel Almeida"],
+    description: "Rust USB driver sample",
+    license: "GPL v2",
+}

-- 
2.50.1