samples: rust: Add spi_dummy

Signed-off-by: Esteban Blanc <[email protected]>

Author: Skallwar

samples/rust/Kconfig

@@ -37,4 +37,14 @@ config SAMPLE_RUST_HOSTPROGS
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_SPI_DUMMY
+	tristate "SPI dummy"
+	help
+	  This option builds the Rust SPI dummy sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_spi_dummy.
+
+	  If unsure, say N.
+
 endif # SAMPLES_RUST

samples/rust/Makefile

@@ -2,5 +2,6 @@
 
 obj-$(CONFIG_SAMPLE_RUST_MINIMAL)		+= rust_minimal.o
 obj-$(CONFIG_SAMPLE_RUST_PRINT)			+= rust_print.o
+obj-$(CONFIG_SAMPLE_RUST_SPI_DUMMY)		+= spi_dummy.o
 
 subdir-$(CONFIG_SAMPLE_RUST_HOSTPROGS)		+= hostprogs

samples/rust/spi_dummy.rs

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use alloc::boxed::Box;
+use core::pin::Pin;
+use kernel::prelude::*;
+use kernel::spi::*;
+use kernel::c_str;
+
+module! {
+    type: SPIDummy,
+    name: "rust_spi_dummy",
+    author: "ks0n",
+    description: "SPI Dummy Driver",
+    license: "GPL",
+}
+
+struct SPIDummyMethods;
+
+#[vtable]
+impl SpiMethods for SPIDummyMethods {
+    fn probe(spi_device: &mut SpiDevice) -> Result<i32, Error> {
+        pr_info!("[SPI-RS] SPI Registered\n");
+        pr_info!(
+            "[SPI-RS] SPI Registered, spi_device = {:#?}\n",
+            spi_device.to_ptr()
+        );
+
+        Ok(0)
+    }
+}
+
+struct SPIDummy {
+    _spi: Pin<Box<DriverRegistration<SPIDummyMethods>>>,
+}
+
+impl kernel::Module for SPIDummy {
+    fn init(module: &'static ThisModule) -> Result<Self> {
+        pr_info!("[SPI-RS] Init\n");
+
+        let spi = DriverRegistration::new_pinned(module, c_str!("SPIDummy"))?;
+
+        Ok(SPIDummy { _spi: spi })
+    }
+}
+
+impl Drop for SPIDummy {
+    fn drop(&mut self) {
+        pr_info!("[SPI-RS] Exit\n");
+    }
+}