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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>
148 lines
3.8 KiB
Rust
148 lines
3.8 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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//! Rust I2C client registration sample.
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//!
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//! An I2C client in Rust cannot exist on its own. To register a new I2C client,
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//! it must be bound to a parent device. In this sample driver, a platform device
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//! is used as the parent.
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//!
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//! ACPI match table test
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//!
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//! This demonstrates how to test an ACPI-based Rust I2C client registration driver
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//! using QEMU with a custom SSDT.
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//!
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//! Steps:
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//!
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//! 1. **Create an SSDT source file** (`ssdt.dsl`) with the following content:
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//!
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//! ```asl
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//! DefinitionBlock ("", "SSDT", 2, "TEST", "VIRTACPI", 0x00000001)
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//! {
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//! Scope (\_SB)
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//! {
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//! Device (T432)
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//! {
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//! Name (_HID, "LNUXBEEF") // ACPI hardware ID to match
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//! Name (_UID, 1)
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//! Name (_STA, 0x0F) // Device present, enabled
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//! Name (_CRS, ResourceTemplate ()
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//! {
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//! Memory32Fixed (ReadWrite, 0xFED00000, 0x1000)
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//! })
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//! }
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//! }
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//! }
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//! ```
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//!
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//! 2. **Compile the table**:
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//!
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//! ```sh
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//! iasl -tc ssdt.dsl
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//! ```
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//!
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//! This generates `ssdt.aml`
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//!
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//! 3. **Run QEMU** with the compiled AML file:
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//!
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//! ```sh
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//! qemu-system-x86_64 -m 512M \
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//! -enable-kvm \
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//! -kernel path/to/bzImage \
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//! -append "root=/dev/sda console=ttyS0" \
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//! -hda rootfs.img \
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//! -serial stdio \
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//! -acpitable file=ssdt.aml
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//! ```
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//!
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//! Requirements:
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//! - The `rust_driver_platform` must be present either:
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//! - built directly into the kernel (`bzImage`), or
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//! - available as a `.ko` file and loadable from `rootfs.img`
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//!
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//! 4. **Verify it worked** by checking `dmesg`:
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//!
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//! ```
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//! rust_driver_platform LNUXBEEF:00: Probed with info: '0'.
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//! ```
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//!
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use kernel::{
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acpi,
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c_str,
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device,
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devres::Devres,
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i2c,
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of,
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platform,
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prelude::*,
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sync::aref::ARef, //
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};
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#[pin_data]
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struct SampleDriver {
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parent_dev: ARef<platform::Device>,
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#[pin]
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_reg: Devres<i2c::Registration>,
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}
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kernel::of_device_table!(
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OF_TABLE,
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MODULE_OF_TABLE,
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<SampleDriver as platform::Driver>::IdInfo,
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[(of::DeviceId::new(c_str!("test,rust-device")), ())]
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);
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kernel::acpi_device_table!(
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ACPI_TABLE,
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MODULE_ACPI_TABLE,
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<SampleDriver as platform::Driver>::IdInfo,
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[(acpi::DeviceId::new(c_str!("LNUXBEEF")), ())]
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);
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const SAMPLE_I2C_CLIENT_ADDR: u16 = 0x30;
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const SAMPLE_I2C_ADAPTER_INDEX: i32 = 0;
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const BOARD_INFO: i2c::I2cBoardInfo =
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i2c::I2cBoardInfo::new(c_str!("rust_driver_i2c"), SAMPLE_I2C_CLIENT_ADDR);
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impl platform::Driver for SampleDriver {
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type IdInfo = ();
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const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
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const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
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fn probe(
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pdev: &platform::Device<device::Core>,
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_info: Option<&Self::IdInfo>,
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) -> impl PinInit<Self, Error> {
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dev_info!(
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pdev.as_ref(),
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"Probe Rust I2C Client registration sample.\n"
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);
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kernel::try_pin_init!( Self {
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parent_dev: pdev.into(),
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_reg <- {
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let adapter = i2c::I2cAdapter::get(SAMPLE_I2C_ADAPTER_INDEX)?;
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i2c::Registration::new(&adapter, &BOARD_INFO, pdev.as_ref())
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}
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})
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}
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fn unbind(pdev: &platform::Device<device::Core>, _this: Pin<&Self>) {
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dev_info!(
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pdev.as_ref(),
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"Unbind Rust I2C Client registration sample.\n"
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);
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}
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}
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kernel::module_platform_driver! {
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type: SampleDriver,
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name: "rust_device_i2c",
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authors: ["Danilo Krummrich", "Igor Korotin"],
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description: "Rust I2C client registration",
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license: "GPL v2",
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}
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