From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B969364E9D for ; Wed, 19 Nov 2025 14:11:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.66 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763561496; cv=none; b=D/O38BvH/m9qOuStz7QL78/f6GNvAX3ahnOJLfw42OV+JTULlT8tyH/pWgY/rDNz+I7Wic8auDUrMgjqjoRMPG+/fD0WEpzL3JdCjvxERqfWIA6G7UsyfMaAUXBywOHIWwBp3k5V69MplFQ/lu1LOaPBgEkalXVQKj6LZy+VhiY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763561496; c=relaxed/simple; bh=DY3Bm4NtAYa457ryVSDZmJmWwlLWDBAI1VLaFfmXsF8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Y6U5hULN6ZabMv0qgSSWesc9IiiFu9BMNNoiC/eEaZJM5TLek13R4UpSKYCwqj3Rvwyr19g4X22q28TUZXX21R1IhuwnkLbmpJ2wc3zNvGKUxMlfyqj2kL2d/ZgKDnFyhuACJRz7S8fy+KvR79LtQxRrlvhiWj7ZjWKOuYLUZdI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de; spf=pass smtp.mailfrom=posteo.de; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b=T9s+5sNJ; arc=none smtp.client-ip=185.67.36.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b="T9s+5sNJ" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id E0126240106 for ; Wed, 19 Nov 2025 15:11:27 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1763561487; bh=2sINMZR+Orb1e0bIRwpcjQBgTeoK31kcru61/G6qYSE=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=T9s+5sNJsvVqhcIx9hnG4w3R9ao42HMDT6S6TlOh5CfFMd1lxjG8TO6JGIMrxpION T8px82F96vBUQi5ZyZ5q/3zTIlDookWY6xxNOie9MbjVxLAegJYAGnWgG4dEibPGmO vqSAZU/HDO0ME1dmpGE6FtXow3kranS0QssufJ7ww1Y2L01Hf0BEajyqcATDHRzh1X HvthiCY/xCIN4bhJf6OySR8M3l3h8XhSpfjaTjZRT9e3YxDxUkF+vpyRLWlM4h5jvr 40rkZwO/8WQktEAqgs4uZGcdbGGM1y4PQDvTJEirVcgoS+kJexyw9KrK9bbycR/5LP BeFMEqUW8opdg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4dBNgw4QZgz6v2f; Wed, 19 Nov 2025 15:11:24 +0100 (CET) From: Markus Probst Date: Wed, 19 Nov 2025 14:11:26 +0000 Subject: [PATCH v9 3/3] rust: leds: add multicolor classdev abstractions Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251119-rust_leds-v9-3-86c15da19063@posteo.de> References: <20251119-rust_leds-v9-0-86c15da19063@posteo.de> In-Reply-To: <20251119-rust_leds-v9-0-86c15da19063@posteo.de> To: Lee Jones , Pavel Machek , Greg Kroah-Hartman , Dave Ertman , Ira Weiny , Leon Romanovsky , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , "Rafael J. Wysocki" , Bjorn Helgaas , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= Cc: rust-for-linux@vger.kernel.org, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Markus Probst X-Developer-Signature: v=1; a=openpgp-sha256; l=9583; i=markus.probst@posteo.de; h=from:subject:message-id; bh=DY3Bm4NtAYa457ryVSDZmJmWwlLWDBAI1VLaFfmXsF8=; b=owEBbQKS/ZANAwAIATR2H/jnrUPSAcsmYgBpHdAEEYjQaao77eh/AETH+S0LG0GOjWF9QgXQe 83ayJq+TMiJAjMEAAEIAB0WIQSCdBjE9KxY53IwxHM0dh/4561D0gUCaR3QBAAKCRA0dh/4561D 0uT3D/90bs7tPvN5PTqcymMqxechfcFSJQiuBcupF00h7mtW+e3zc8rqqeG+Po8Ud/gfj2k1kKN FOjexFRC0EWSXn08YPxqaE0j2InwrXyMl7y6OyfdSivRU9EUtv/b4E8x9/wPwc0chTf/PkteLqr +T0JPWkvLnG/Uv/Bd2fSbhEPP62fpqLg2Wn4UXDpmAxPSJ2axyh4qOP0ic4sX04DAgJL+vfxDp2 9GG2JKhNFRvvok13cYFUW9tJ+pQldKgBUOHOQbewvZ7ywNYdQP9hgQQlSqXtBOqJTxMlke/dhu8 PPemVGlSkN/cMQolkjEWkgmVKSasJeZ/0Dlc4Gy+QyOL4B2UZmwocVAjnBLNnM7P8WMFR6FK21I jH2BaMBrPIeQ+cTHnrkqICrhTvwrVYJOrcZ67WdFyd6ScIDzLTKnjAGiZtoGG9cE4S2kyqWI8En Q2a4+Q4wQgx0BSg/8mxTPrZGCYkhHeFfat6IG8SMyn8Sc7RPP5WAHojWXQiloel2aufHhSW7IP0 dJEcwVrhZmQOjmW6vSyl+n8CX1vU3G+c/6VnN9CoadUA3+3qab8qsxGDIOQaZlppQ54VTV83jw1 rJcQRn8ougqfcLwiYk4zEvq4+0pbHE69CrMhFndr5OJUE/eRkum9R0K52SI2IR9X0Vg8lWWbGzT jUrF305DM+u9TTA== X-Developer-Key: i=markus.probst@posteo.de; 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preference=encrypt Implement the abstractions needed for multicolor led class devices, including: * `led::MultiColor` - the led mode implementation * `MultiColorSubLed` - a safe wrapper arround `mc_subled` * `led::Device::new_multicolor()` - the function to register a multicolor led class device * `led::Device::subleds()` - the function to access the brightness and intensity of the individual sub leds Signed-off-by: Markus Probst --- rust/bindings/bindings_helper.h | 1 + rust/kernel/led.rs | 13 ++- rust/kernel/led/multicolor.rs | 195 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 208 insertions(+), 1 deletion(-) diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index f92abb578b56..8825b6df9c9e 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -62,6 +62,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs index d51735322093..7c1f6252605f 100644 --- a/rust/kernel/led.rs +++ b/rust/kernel/led.rs @@ -44,8 +44,12 @@ }, // }; +#[cfg(CONFIG_LEDS_CLASS_MULTICOLOR)] +mod multicolor; mod normal; +#[cfg(CONFIG_LEDS_CLASS_MULTICOLOR)] +pub use multicolor::{MultiColor, MultiColorSubLed}; pub use normal::Normal; /// The led class device representation. @@ -285,7 +289,14 @@ fn try_from(value: u32) -> core::result::Result { /// /// Each led mode has its own led class device type with different capabilities. /// -/// See [`Normal`]. +#[cfg_attr( + CONFIG_LEDS_CLASS_MULTICOLOR, + doc = "See [`Normal`] and [`MultiColor`]." +)] +#[cfg_attr( + not(CONFIG_LEDS_CLASS_MULTICOLOR), + doc = "See [`Normal`] and `MultiColor`." +)] pub trait Mode: private::Mode {} impl Mode for T {} diff --git a/rust/kernel/led/multicolor.rs b/rust/kernel/led/multicolor.rs new file mode 100644 index 000000000000..db5935448bd7 --- /dev/null +++ b/rust/kernel/led/multicolor.rs @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Led mode for the `struct led_classdev_mc`. +//! +//! C header: [`include/linux/led-class-multicolor.h`](srctree/include/linux/led-class-multicolor.h) + +use crate::{ + alloc::KVec, + error::code::EINVAL, + prelude::*, // +}; + +use super::*; + +/// The led mode for the `struct led_classdev_mc`. Leds with this mode can have multiple colors. +pub enum MultiColor {} + +/// The multicolor sub led info representation. +/// +/// This structure represents the Rust abstraction for a C `struct mc_subled`. +#[repr(C)] +#[derive(Copy, Clone, Debug)] +pub struct MultiColorSubLed { + /// the color of the sub led + pub color: Color, + /// the brightness of the sub led. + /// + /// The value will be automatically calculated. + /// See `MultiColor::pre_brightness_set`. + pub brightness: u32, + /// the intensity of the sub led. + pub intensity: u32, + /// arbitrary data for the driver to store. + pub channel: u32, + _p: PhantomData<()>, // Only allow creation with `MultiColorSubLed::new`. +} + +// We directly pass a reference to the `subled_info` field in `led_classdev_mc` to the driver via +// `Device::subleds()`. +// We need safeguards to ensure `MultiColorSubLed` and `mc_subled` stay identical. +const _: () = { + use core::mem::offset_of; + + const fn assert_same_type(_: &T, _: &T) {} + + let rust_zeroed = MultiColorSubLed { + color: Color::White, + brightness: 0, + intensity: 0, + channel: 0, + _p: PhantomData, + }; + let c_zeroed = bindings::mc_subled { + color_index: 0, + brightness: 0, + intensity: 0, + channel: 0, + }; + + assert!(offset_of!(MultiColorSubLed, color) == offset_of!(bindings::mc_subled, color_index)); + assert_same_type(&0u32, &c_zeroed.color_index); + + assert!( + offset_of!(MultiColorSubLed, brightness) == offset_of!(bindings::mc_subled, brightness) + ); + assert_same_type(&rust_zeroed.brightness, &c_zeroed.brightness); + + assert!(offset_of!(MultiColorSubLed, intensity) == offset_of!(bindings::mc_subled, intensity)); + assert_same_type(&rust_zeroed.intensity, &c_zeroed.intensity); + + assert!(offset_of!(MultiColorSubLed, channel) == offset_of!(bindings::mc_subled, channel)); + assert_same_type(&rust_zeroed.channel, &c_zeroed.channel); + + assert!(size_of::() == size_of::()); +}; + +impl MultiColorSubLed { + /// Create a new multicolor sub led info. + pub const fn new(color: Color) -> Self { + Self { + color, + brightness: 0, + intensity: 0, + channel: 0, + _p: PhantomData, + } + } + + /// Set arbitrary data for the driver. + pub const fn channel(mut self, channel: u32) -> Self { + self.channel = channel; + self + } + + /// Set the initial intensity of the subled. + pub const fn initial_intensity(mut self, intensity: u32) -> Self { + self.intensity = intensity; + self + } +} + +impl private::Mode for MultiColor { + type Type = bindings::led_classdev_mc; + const REGISTER: RegisterFunc = bindings::led_classdev_multicolor_register_ext; + const UNREGISTER: UnregisterFunc = bindings::led_classdev_multicolor_unregister; + + unsafe fn device<'a>(raw: *mut Self::Type) -> &'a device::Device { + // SAFETY: + // - The function's contract guarantees that `raw` is a valid pointer to `led_classdev`. + unsafe { device::Device::from_raw((*raw).led_cdev.dev) } + } + + unsafe fn from_classdev(led_cdev: *mut bindings::led_classdev) -> *mut Self::Type { + // SAFETY: The function's contract guarantees that `led_cdev` is a valid pointer to + // `led_classdev` embedded within a `Self::Type`. + unsafe { container_of!(led_cdev, bindings::led_classdev_mc, led_cdev) } + } + + unsafe fn pre_brightness_set(raw: *mut Self::Type, brightness: u32) { + // SAFETY: The function's contract guarantees that `raw` is a valid pointer to + // `led_classdev_mc`. + unsafe { bindings::led_mc_calc_color_components(raw, brightness) }; + } + + fn release(led_cdev: &mut Self::Type) { + // SAFETY: `subled_info` is guaranteed to be a valid array pointer to `mc_subled` with the + // length and capacity of `led_cdev.num_colors`. See `led::Device::new_multicolor`. + let _subleds_vec = unsafe { + KVec::from_raw_parts( + led_cdev.subled_info, + led_cdev.num_colors as usize, + led_cdev.num_colors as usize, + ) + }; + } +} + +impl> Device { + /// Registers a new multicolor led classdev. + /// + /// The [`Device`] will be unregistered on drop. + pub fn new_multicolor<'a>( + parent: &'a T::Bus, + init_data: InitData<'a>, + ops: T, + subleds: &'a [MultiColorSubLed], + ) -> impl PinInit, Error> + 'a { + assert!(subleds.len() <= u32::MAX as usize); + Self::__new(parent, init_data, ops, |led_cdev| { + let mut subleds_vec = KVec::new(); + subleds_vec.extend_from_slice(subleds, GFP_KERNEL)?; + let (subled_info, num_colors, capacity) = subleds_vec.into_raw_parts(); + debug_assert_eq!(num_colors, capacity); + + let mut used = 0; + if subleds.iter().any(|subled| { + let bit = 1 << (subled.color as u32); + if (used & bit) != 0 { + true + } else { + used |= bit; + false + } + }) { + dev_err!(parent.as_ref(), "duplicate color in multicolor led\n"); + return Err(EINVAL); + } + + Ok(bindings::led_classdev_mc { + led_cdev, + // CAST: We checked above that the length of subleds fits into a u32. + num_colors: num_colors as u32, + // CAST: The safeguards in the const block ensure that `MultiColorSubLed` has an + // identical layout to `mc_subled`. + subled_info: subled_info.cast::(), + }) + }) + } + + /// Returns the subleds passed to [`Device::new_multicolor`]. + pub fn subleds(&self) -> &[MultiColorSubLed] { + // SAFETY: The existence of `self` guarantees that `self.classdev.get()` is a pointer to a + // valid `led_classdev_mc`. + let raw = unsafe { &*self.classdev.get() }; + // SAFETY: `raw.subled_info` is a valid pointer to `mc_subled[num_colors]`. + // CAST: The safeguards in the const block ensure that `MultiColorSubLed` has an identical + // layout to `mc_subled`. + unsafe { + core::slice::from_raw_parts( + raw.subled_info.cast::(), + raw.num_colors as usize, + ) + } + } +} -- 2.51.0