samples/rust: add platform device driver sample

This is a minimal sample of registering a driver for a platform device.
The driver doesn't really do anything, and serves as a template for
future new platform drivers.

Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>

Author: wedsonaf

samples/rust/Kconfig

@@ -110,4 +110,14 @@ config SAMPLE_RUST_RANDOM
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_PLATFORM
+	tristate "Platform device driver"
+	help
+	  This option builds the Rust platform device driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_platform.
+
+	  If unsure, say N.
+
 endif # SAMPLES_RUST

samples/rust/Makefile

@@ -10,3 +10,4 @@ obj-$(CONFIG_SAMPLE_RUST_STACK_PROBING)		+= rust_stack_probing.o
 obj-$(CONFIG_SAMPLE_RUST_SEMAPHORE)		+= rust_semaphore.o
 obj-$(CONFIG_SAMPLE_RUST_SEMAPHORE_C)		+= rust_semaphore_c.o
 obj-$(CONFIG_SAMPLE_RUST_RANDOM)		+= rust_random.o
+obj-$(CONFIG_SAMPLE_RUST_PLATFORM)		+= rust_platform.o

samples/rust/rust_platform.rs

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust platform device driver sample.
+
+#![no_std]
+#![feature(allocator_api, global_asm)]
+
+use kernel::{module_platform_driver, of, platform, prelude::*};
+
+module_platform_driver! {
+    type: Driver,
+    name: b"rust_platform",
+    license: b"GPL v2",
+}
+
+struct Driver;
+impl platform::Driver for Driver {
+    kernel::define_of_id_table! {(), [
+        (of::DeviceId::Compatible(b"rust,sample"), None),
+    ]}
+
+    fn probe(_dev: &mut platform::Device, _id_info: Option<&Self::IdInfo>) -> Result {
+        Ok(())
+    }
+}