From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f44.google.com (mail-wr1-f44.google.com [209.85.221.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 90BAA1C6B4 for ; Sun, 5 Oct 2025 10:22:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759659754; cv=none; b=b+tQu2uXMLhd51T0PuSir/gK70q7DYPccprAlsa5Xiv3N2Qp9nvYlDFekrvJLqkipEEE1Z1YY3Xxr9la59QBf/wbPfEefqvCwdf2ForoRYn24bfb6nBrjdafRQiotTh5/MHA513+5XMnuZhLQWoZ9xFM+imrjwBgAEgwdtuWJtY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759659754; c=relaxed/simple; bh=014TfYqN3Jm51Kwrsshh0C7lrXndtjXKzXJvEQMsYt0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Vf0skSqEkzSwRlZpFHfh0mpplsryG8YEvH7Q6mcrKny3AlXn16W4XfSJQ2DNkb8M+w6gduwirr+ewbmfBrhwLHyQF1HKz81LmsFJfg21DF//sQ9T2bFRae8rP9JrUU6SXn80Jq7Ve8vYR0qv9qiyyHiq/myNz7tiQ04tZx3eOOU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=f4eag9q4; arc=none smtp.client-ip=209.85.221.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="f4eag9q4" Received: by mail-wr1-f44.google.com with SMTP id ffacd0b85a97d-3fc36b99e92so3429586f8f.0 for ; Sun, 05 Oct 2025 03:22:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1759659751; x=1760264551; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=iOWcLazJ0KI6bew1rjQOg+oZIoGTP/PL0YVWlyFt/TI=; b=f4eag9q4K8US4NHOBPyaW6BCDZMdEjxZMP8StfPTaOYVtE8aOL0p2uTAN3CFNQWOHE YkyK4phzHrcuFoveoOzBnLpVMVp7Q/8cQ0NSbnki4Bxf0NoKgOYVfpx2PA4RanHbETTC 4J/w1uahtYX5zAuf6piMxQOSkVh49QonABdades0KTSBzDApyZ0D7q+4XC5KEf+vcY5G OANOfmJaRrhkqc7+BsW4275XNxBP7FAr8kbJcWGeM7YdPnwm2lRC+baqF0pI/P2pm0eK vxOpZh2K3cbATjZIZDP97iOiomuhNFeFA4NkR/C9DmqaSNVj2VmU25o4ZlqSdxTDQqMN kwGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759659751; x=1760264551; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=iOWcLazJ0KI6bew1rjQOg+oZIoGTP/PL0YVWlyFt/TI=; b=jmj7HFYQt9Xyd2UcvalIu/6ak3ONA43W40v+IHxBLj33BfymeC3nBZcCU/eWO3deRJ 1CJbu6EsdD991nVjFHCwjSlqHSE1Xt5jDRY4Y7J6YhkKdXnLBLBWlG46jbmuVXsetaJa xzpCQ6FCoqM8cQW79TvpFP+x7+vv6KpDLSigHGPTkdRHdA66Ua+N37oAqnsi+TfamirM /lZRZHbpqx1kB6DwEtLVwHAWpfnpiKZGs7Y8rTNtZUqfPAW7+0ZugZ0b/+AF+mbRiUTR ud3dwhAQXnWnN78xDVOdk1CAHeVt4IvvZhS3HBpLpZ9UA+tRQl9MWKR5VXaM+rs4X61G KdGw== X-Forwarded-Encrypted: i=1; AJvYcCX3NKH9aKkVMl+L1Xv1u2awbv6nIDxxCKLhAjh5kOsd7ch8YRa/xonSZgyf+31oCGptEGmTQ/jrWX4=@vger.kernel.org X-Gm-Message-State: AOJu0YwLoTwfEDfr1oYWjBdYj+Mo4E2E3dDaurXjLq80P2wdxzq6wgqR rxelo4SEvkOFC9rX4cdpwX7ZllV9bg8yc+Eckq+9Y0OQ3RLK1lGnKbej X-Gm-Gg: ASbGncuJHaTfQcYuVrK8aY1D4ItnzoxyWLL6jGlo5G91TEZMJ7tW/Y2n7pqvwmKpAgu u+AaJfM3gxwzaookskF+9BUue81bvkBXD1C9kO63vp4NYErlVpv4S6vhDGkIoEaZ/edZf5EQeOd j1npryIezD0hVnV54EOrIDRT9yMGoPx7Mw/20gGiEGlcVPlMViRlD6PBatRNHv9mXHaYZVW+XYN WOBo5wo3eNlBV0WPLa4XLVg8sMH+3UUMS4uiOEIEl4HuR2mP2FokDboSOX/gfDCKmvbfPNVG6aa 5Oh0xr30HIgcXJJdxYM2VPPF8xtUlva0blZvALPpQ7tu6JxqaGch9CEDE1LEK6kBKq7HniFSbv0 YGuypg3bOGgxuRoB+rgA3apjmiq1DpAlPU62z1jFEx6d0BGi8vIKM8oOi X-Google-Smtp-Source: AGHT+IFQqIQ2T67iM4l0Z9hio/dmJ+0gCd9LzgbFU3MTDe0hCh0YE0mZQ4+Qxw9DEq0sf2IHE4GZfw== X-Received: by 2002:a5d:64e9:0:b0:3e7:6424:1b47 with SMTP id ffacd0b85a97d-42566c00d2fmr6523458f8f.6.1759659750540; Sun, 05 Oct 2025 03:22:30 -0700 (PDT) Received: from Vasilio.Home ([2.127.51.206]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4255d8e9762sm15822332f8f.38.2025.10.05.03.22.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 05 Oct 2025 03:22:30 -0700 (PDT) From: Igor Korotin To: Miguel Ojeda , Alex Gaynor , Wolfram Sang Cc: Boqun Feng , Gary Guo , =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Greg Kroah-Hartman , Viresh Kumar , Asahi Lina , Wedson Almeida Filho , Alex Hung , Tamir Duberstein , Xiangfei Ding , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-i2c@vger.kernel.org Subject: [PATCH v6 0/3] rust: i2c: Add basic I2C driver abstractions Date: Sun, 5 Oct 2025 11:22:26 +0100 Message-ID: <20251005102226.41876-1-igor.korotin.linux@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch series lays the groundwork for writing Linux I2C drivers in Rust by: 1. Core abstractions Introduce `i2c::I2cClient`, `i2c::I2cAdapter`, `i2c::Driver` and built on the existing `struct i2c_client`, `struct i2c_adapter` and `struct i2c_driver`, with safe Rust wrappers around probe, transfer, and teardown logic. 2. Manual device creation Provide an API to register an I2C device at runtime from Rust using `I2cBoardInfo` and `I2cAdapter`, including automatic cleanup when the driver unloads. 3. Sample driver (legacy table, OF & ACPI) Add `rust_driver_i2c`, a sample that: - creates an I2C client device using `i2c::Registration::new()` - binds to an I2C client via: - legacy I2C-ID table, - Open Firmware (device-tree) compatible strings, or - ACPI IDs. - destroyes the I2C client device on exit. Together, these three patches: - Establish the essential Rust traits and types for I2C drivers. - Enable driver binding via legacy ID table, device-tree (OF), or ACPI - Enable manual device creation at runtime. - Ship a samples showing typical usage Igor Korotin (3): rust: i2c: add basic I2C device and driver abstractions rust: i2c: add manual I2C device creation abstractions samples: rust: add Rust I2C sample driver Changelog --------- v6: - Add implementation of unbind for `i2c::Driver` trait; - Add argument `Pin<&Self>` to `i2c::Driver::shutdown` method; - Adjust usage of `i2c::Driver::shutdown` in `i2c::Adapter::shutdown_callback` in `i2c::Driver` trait code example and in rust_driver_i2c code; - Remove dummy AsRef implementation for I2cAdapter. Adjust code in rust_driver_i2c; - Add `i2c::I2cAdapter::get_nr` method that returns I2cAdapter index; - Optimize unsafe sections in inc_ref/dec_ref in AlwaysRefCounted for I2cAdapter implementation; - Remove unnecessary Drop implementation for I2cAdapter, because I2cAdapter is always a reference; - Remove unnecessary type definition `Ops` in rust_driver_i2c - Simplify call of `i2c::I2cAdapter::get` in `try_pin_init!` macro for rust_driver_i2c - Link to v5: https://lore.kernel.org/rust-for-linux/20250911154717.96637-1-igor.korotin.linux@gmail.com/ v5: - Rename missed pdev variables to idev (thanks to Daniel). - Import `crate::device_id::RawDeviceIdIndex` and `crate::types::AlwaysRefCounted` in i2c.rs. - Switch dev_dbg to dev_info in the sample I2C driver messages. - Make `I2cAdapter::get()` return `ARef` instead of `&I2cAdapter`. - Remove `TryFrom> for I2cAdapter` (unused; to be reintroduced in a later I2C series). - Remove `AsRef> for I2cAdapter` (unused; to be reintroduced in a later I2C series). - Add `AsRef for I2cAdapter`. - Use i2c_get/put_adapter instead of get/put_device for `AlwaysRefCounted`. - Update safety comment for `unsafe impl Sync for Registration {}`. - Tweak comment for `I2cBoardInfo::new`. - Adjust build-time assertion message in `Adapter::register`. - Link to v4: https://lore.kernel.org/rust-for-linux/20250820151427.1812482-1-igor.korotin.linux@gmail.com/ v4: - Renamed `i2c::I2cAdapterRef` to `i2c::I2cAdapter`. - Renamed `i2c::Device` to `i2c::I2cClient` for consistency with `i2c::I2cAdapter` and to avoid confusion with `i2c::Adapter` - Reworked `i2c::I2cAdapter` to be an Opaque around `i2c_adapter` struct - Implemented AlwaysRefCounted trait for `i2c::I2cAdapter`. - Fixed numerous comment mistakes and typos all over the code, thanks to Danilo and Daniel - Got rid of all unwrap() use-cases in i2c.rs and rust_driver_i2c.rs. This covers 0-day kernel panic <202508071027.8981cbd4-lkp@intel.com> - Removed unnecessary casts. - Replaced all addr_of_mut! macros to &raw mut. - In `i2c::Adapter::register` method build assert if all ID tables are None. - Renamed all pdrv and pdev instances to idrv and idev respectivly - Implemented an ealry return in `i2c::Adapter::i2c_id_info` - Added all missing Safety comments. - Removed `unsafe impl crate::types::AlwaysRefCounted for Device` implementation which came to v3 from v2 by mistake. - Added more details regarding i2c-stub driver usage in rust_driver_i2c comment. - Changed `i2c::I2cAdapter::get` return type from `Option` to `Result<&'static Self>`. - Added Daniel Almeida as a reviewer to the "I2C Subsystem [RUST]" entry in MAINTAINERS, per his offer. - Link to v3: https://lore.kernel.org/rust-for-linux/20250801153742.13472-1-igor.korotin.linux@gmail.com/ v3: - removed unnecessary i2c_get_clientdata and i2c_set_clientdata rust helpers. Using generic accessors implemented in [1] instead. - Reimplemented i2c::DeviceId based on changes in [2]. - Using from_result in i2c::Adapter::probe_callback - Using explicit drop() for i2c client private data in `i2c::Adapter::remove_callback` - replaced device::Device::as_ref() with device::Device::from_raw in `i2c::Device::as_ref()`. It is renamed in device::Device. - Build Rust I2C only if I2C is built-in - Reimplement overcomplicated trait i2c::DeviceOwned the same way it is implemented in auxiliary [3]. - Merge rust_device_i2c and rust_driver_i2c samples. Resulting rust_driver_i2c creates pined i2c_client using i2c::Registration::new and probes newly created i2c_client. - Created a new entry in MAINTAINERS file containing i2c.rs and rust_driver_i2c.rs in it. - Link to v2: [4] [1] https://lore.kernel.org/lkml/20250621195118.124245-3-dakr@kernel.org/ [2] https://lore.kernel.org/rust-for-linux/20250711040947.1252162-1-fujita.tomonori@gmail.com/ [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/rust/kernel/auxiliary.rs?h=v6.16-rc4#n299 [4] https://lore.kernel.org/rust-for-linux/20250704153332.1193214-1-igor.korotin.linux@gmail.com/ v2: - Merged separated ACPI support patches since ACPI-table support is merged into driver-core-next. - Added I2cAdapterRef and I2cBoardInfo abstractions - Added DeviceState generic parameter which is used for `i2c::Device` as a sign if the device is created manually - Added `DeviceOwned` abstraction which is a safe reference to a manually created `i2c::Device`. - Added Rust manual I2C device creation sample - Link to v1: https://lore.kernel.org/rust-for-linux/20250626174623.904917-1-igor.korotin.linux@gmail.com/ MAINTAINERS | 9 + rust/bindings/bindings_helper.h | 1 + rust/kernel/i2c.rs | 565 ++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 2 + samples/rust/Kconfig | 11 + samples/rust/Makefile | 1 + samples/rust/rust_driver_i2c.rs | 126 +++++++ 7 files changed, 715 insertions(+) create mode 100644 rust/kernel/i2c.rs create mode 100644 samples/rust/rust_driver_i2c.rs base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585 -- 2.43.0