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samples: rust: add Rust I2C client registration sample

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Add a new `rust_i2c_client` sample, showing how to create a new
i2c client using `i2c::Registration`

Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20251116162210.171542-1-igor.korotin.linux@gmail.com
[ * Remove dependency to I2C_CHARDEV, depend on I2C=y.
  * Remove unnecessary impl Drop for SampleDriver.
  * Rename i2c::Registration, import Devres.
  * Fixup module description.
  * Add new source file to MAINTAINERS.
  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
This commit is contained in:
Igor Korotin
2025-11-16 16:22:10 +00:00
committed by Danilo Krummrich
parent d05b8e9769
commit 13ae55e24a
4 changed files with 161 additions and 0 deletions
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1
MAINTAINERS
View File

@@ -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>

12
samples/rust/Kconfig
View File

@@ -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

1
samples/rust/Makefile
View File

@@ -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

147
samples/rust/rust_i2c_client.rs Normal file
View File

@@ -0,0 +1,147 @@
// 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",
}