[PATCH v3 16/16] samples: rust: add Rust platform sample driver

[Danilo Krummrich <dakr@kernel.org>]

Add a sample Rust platform driver illustrating the usage of the platform
bus abstractions.

This driver probes through either a match of device / driver name or a
match within the OF ID table.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 MAINTAINERS                          |  1 +
 samples/rust/Kconfig                 | 10 +++++
 samples/rust/Makefile                |  1 +
 samples/rust/rust_driver_platform.rs | 62 ++++++++++++++++++++++++++++
 4 files changed, 74 insertions(+)
 create mode 100644 samples/rust/rust_driver_platform.rs

diff --git a/MAINTAINERS b/MAINTAINERS
index 173540375863..583b6588fd1e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6986,6 +6986,7 @@ F:	rust/kernel/device_id.rs
 F:	rust/kernel/devres.rs
 F:	rust/kernel/driver.rs
 F:	rust/kernel/platform.rs
+F:	samples/rust/rust_driver_platform.rs
 
 DRIVERS FOR OMAP ADAPTIVE VOLTAGE SCALING (AVS)
 M:	Nishanth Menon <nm@ti.com>
diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
index 6d468193cdd8..70126b750426 100644
--- a/samples/rust/Kconfig
+++ b/samples/rust/Kconfig
@@ -41,6 +41,16 @@ config SAMPLE_RUST_DRIVER_PCI
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_DRIVER_PLATFORM
+	tristate "Platform Driver"
+	help
+	  This option builds the Rust Platform driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_platform.
+
+	  If unsure, say N.
+
 config SAMPLE_RUST_HOSTPROGS
 	bool "Host programs"
 	help
diff --git a/samples/rust/Makefile b/samples/rust/Makefile
index b66767f4a62a..11fcb312ed36 100644
--- a/samples/rust/Makefile
+++ b/samples/rust/Makefile
@@ -3,5 +3,6 @@
 obj-$(CONFIG_SAMPLE_RUST_MINIMAL)		+= rust_minimal.o
 obj-$(CONFIG_SAMPLE_RUST_PRINT)			+= rust_print.o
 obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI)		+= rust_driver_pci.o
+obj-$(CONFIG_SAMPLE_RUST_DRIVER_PLATFORM)	+= rust_driver_platform.o
 
 subdir-$(CONFIG_SAMPLE_RUST_HOSTPROGS)		+= hostprogs
diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
new file mode 100644
index 000000000000..55caaaa4f216
--- /dev/null
+++ b/samples/rust/rust_driver_platform.rs
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust Platform driver sample.
+
+use kernel::{c_str, of, platform, prelude::*};
+
+struct SampleDriver {
+    pdev: platform::Device,
+}
+
+struct Info(u32);
+
+kernel::of_device_table!(
+    OF_TABLE,
+    MODULE_OF_TABLE,
+    <SampleDriver as platform::Driver>::IdInfo,
+    [(
+        of::DeviceId::new(c_str!("redhat,rust-sample-platform-driver")),
+        Info(42)
+    )]
+);
+
+impl platform::Driver for SampleDriver {
+    type IdInfo = Info;
+    const ID_TABLE: platform::IdTable<Self::IdInfo> = &OF_TABLE;
+
+    fn probe(pdev: &mut platform::Device, info: Option<&Self::IdInfo>) -> Result<Pin<KBox<Self>>> {
+        dev_dbg!(pdev.as_ref(), "Probe Rust Platform driver sample.\n");
+
+        match (Self::of_match_device(pdev), info) {
+            (Some(id), Some(info)) => {
+                dev_info!(
+                    pdev.as_ref(),
+                    "Probed by OF compatible match: '{}' with info: '{}'.\n",
+                    id.compatible(),
+                    info.0
+                );
+            }
+            _ => {
+                dev_info!(pdev.as_ref(), "Probed by name.\n");
+            }
+        };
+
+        let drvdata = KBox::new(Self { pdev: pdev.clone() }, GFP_KERNEL)?;
+
+        Ok(drvdata.into())
+    }
+}
+
+impl Drop for SampleDriver {
+    fn drop(&mut self) {
+        dev_dbg!(self.pdev.as_ref(), "Remove Rust Platform driver sample.\n");
+    }
+}
+
+kernel::module_platform_driver! {
+    type: SampleDriver,
+    name: "rust_driver_platform",
+    author: "Danilo Krummrich",
+    description: "Rust Platform driver",
+    license: "GPL v2",
+}
-- 
2.46.2