samples: rust: add Rust I2C client registration sample (13ae55e2) · Commits · git / linux-net

MAINTAINERS

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		@@ -11751,6 +11751,7 @@ L: rust-for-linux@vger.kernel.org
		S: Maintained
		F: rust/kernel/i2c.rs
		F: samples/rust/rust_driver_i2c.rs
		F: samples/rust/rust_i2c_client.rs

		I2C SUBSYSTEM HOST DRIVERS
		M: Andi Shyti <andi.shyti@kernel.org>

samples/rust/Kconfig

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		@@ -95,6 +95,18 @@ config SAMPLE_RUST_DRIVER_I2C

		If unsure, say N.

		config SAMPLE_RUST_I2C_CLIENT
		tristate "I2C Client Registration"
		depends on I2C=y
		help
		This option builds the Rust I2C client manual creation
		sample.

		To compile this as a module, choose M here:
		the module will be called rust_i2c_client.

		If unsure, say N.

		config SAMPLE_RUST_DRIVER_PCI
		tristate "PCI Driver"
		depends on PCI

samples/rust/Makefile

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		@@ -8,6 +8,7 @@ obj-$(CONFIG_SAMPLE_RUST_DEBUGFS) += rust_debugfs.o
		obj-$(CONFIG_SAMPLE_RUST_DEBUGFS_SCOPED) += rust_debugfs_scoped.o
		obj-$(CONFIG_SAMPLE_RUST_DMA) += rust_dma.o
		obj-$(CONFIG_SAMPLE_RUST_DRIVER_I2C) += rust_driver_i2c.o
		obj-$(CONFIG_SAMPLE_RUST_I2C_CLIENT) += rust_i2c_client.o
		obj-$(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

samples/rust/rust_i2c_client.rs

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		// SPDX-License-Identifier: GPL-2.0

		//! Rust I2C client registration sample.
		//!
		//! An I2C client in Rust cannot exist on its own. To register a new I2C client,
		//! it must be bound to a parent device. In this sample driver, a platform device
		//! is used as the parent.
		//!

		//! ACPI match table test
		//!
		//! This demonstrates how to test an ACPI-based Rust I2C client registration driver
		//! using QEMU with a custom SSDT.
		//!
		//! Steps:
		//!
		//! 1. Create an SSDT source file (`ssdt.dsl`) with the following content:
		//!
		//! ```asl
		//! DefinitionBlock ("", "SSDT", 2, "TEST", "VIRTACPI", 0x00000001)
		//! {
		//! Scope (\_SB)
		//! {
		//! Device (T432)
		//! {
		//! Name (_HID, "LNUXBEEF") // ACPI hardware ID to match
		//! Name (_UID, 1)
		//! Name (_STA, 0x0F) // Device present, enabled
		//! Name (_CRS, ResourceTemplate ()
		//! {
		//! Memory32Fixed (ReadWrite, 0xFED00000, 0x1000)
		//! })
		//! }
		//! }
		//! }
		//! ```
		//!
		//! 2. Compile the table:
		//!
		//! ```sh
		//! iasl -tc ssdt.dsl
		//! ```
		//!
		//! This generates `ssdt.aml`
		//!
		//! 3. Run QEMU with the compiled AML file:
		//!
		//! ```sh
		//! qemu-system-x86_64 -m 512M \
		//! -enable-kvm \
		//! -kernel path/to/bzImage \
		//! -append "root=/dev/sda console=ttyS0" \
		//! -hda rootfs.img \
		//! -serial stdio \
		//! -acpitable file=ssdt.aml
		//! ```
		//!
		//! Requirements:
		//! - The `rust_driver_platform` must be present either:
		//! - built directly into the kernel (`bzImage`), or
		//! - available as a `.ko` file and loadable from `rootfs.img`
		//!
		//! 4. Verify it worked by checking `dmesg`:
		//!
		//! ```
		//! rust_driver_platform LNUXBEEF:00: Probed with info: '0'.
		//! ```
		//!

		use kernel::{
		acpi,
		c_str,
		device,
		devres::Devres,
		i2c,
		of,
		platform,
		prelude::*,
		sync::aref::ARef, //
		};

		#[pin_data]
		struct SampleDriver {
		parent_dev: ARef<platform::Device>,
		#[pin]
		_reg: Devres<i2c::Registration>,
		}

		kernel::of_device_table!(
		OF_TABLE,
		MODULE_OF_TABLE,
		<SampleDriver as platform::Driver>::IdInfo,
		[(of::DeviceId::new(c_str!("test,rust-device")), ())]
		);

		kernel::acpi_device_table!(
		ACPI_TABLE,
		MODULE_ACPI_TABLE,
		<SampleDriver as platform::Driver>::IdInfo,
		[(acpi::DeviceId::new(c_str!("LNUXBEEF")), ())]
		);

		const SAMPLE_I2C_CLIENT_ADDR: u16 = 0x30;
		const SAMPLE_I2C_ADAPTER_INDEX: i32 = 0;
		const BOARD_INFO: i2c::I2cBoardInfo =
		i2c::I2cBoardInfo::new(c_str!("rust_driver_i2c"), SAMPLE_I2C_CLIENT_ADDR);

		impl platform::Driver for SampleDriver {
		type IdInfo = ();
		const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
		const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);

		fn probe(
		pdev: &platform::Device<device::Core>,
		_info: Option<&Self::IdInfo>,
		) -> impl PinInit<Self, Error> {
		dev_info!(
		pdev.as_ref(),
		"Probe Rust I2C Client registration sample.\n"
		);

		kernel::try_pin_init!( Self {
		parent_dev: pdev.into(),

		_reg <- {
		let adapter = i2c::I2cAdapter::get(SAMPLE_I2C_ADAPTER_INDEX)?;

		i2c::Registration::new(&adapter, &BOARD_INFO, pdev.as_ref())
		}
		})
		}

		fn unbind(pdev: &platform::Device<device::Core>, _this: Pin<&Self>) {
		dev_info!(
		pdev.as_ref(),
		"Unbind Rust I2C Client registration sample.\n"
		);
		}
		}

		kernel::module_platform_driver! {
		type: SampleDriver,
		name: "rust_device_i2c",
		authors: ["Danilo Krummrich", "Igor Korotin"],
		description: "Rust I2C client registration",
		license: "GPL v2",
		}