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 6A89E40E8C5 for ; Mon, 29 Jun 2026 13:10:35 +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=1782738639; cv=none; b=kYFf6WpgDUvD0heI50NOnjYy5QN+mFVRQ9oOakM3M6vYcv2Xx7yAM7HWNgxqPSpZynL0weUy7PyWPmaGDkXxBGvloNLTFs/cGLSkiDuXiAuifaNA7rfxyFE+h82St97JgBu5V+MF/E7bM8V6DizmdVdgWiOMhni4JsvtAYMnXE8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782738639; c=relaxed/simple; bh=RSsYvswDNkPUr03lsAvodf/Y/Pvm8t3EpULz4JWrGcQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=OsHmipPeWklgmmTTpb9PkWF9hRQLVhdwwuu8138RUrxUmQ1mwxzDqxbwDIyDWS17njfl0v9p48JRLaWJwHsp59ybTBdoAO/1hMGQkj63qDoXGeNLNj4azPdVgJ9PIeSj2fk/Na6zW5+Ef8me+3Jlt1Llj1FalAy/TsnaFDFYnk0= 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=ZRV2UsZ4; 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="ZRV2UsZ4" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id C4CDA24010D for ; Mon, 29 Jun 2026 15:10:33 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1782738634; bh=0qaqqNwBFwkzmDECVhiSzVgfW7P9Nk5HDVgYpAqTmKU=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=ZRV2UsZ40Td8B+V9W7LK5wY79R20iQL9N/k7CSjzkkUumr56BFnhtJGxo46ZkXquM KlfRqi04A6CGc0WVz6wfD/cabWAvc8/7RDwckx/g8ikrqWH/0j1HC7e+jlIxEAsu7F T3mHhe+GchF8+s6JdfH9egPbhxAReoDVDrt+Lnq0OLXk2N92tmQMVtayKMX1hPTpSu tcZT/WPT8sLGPc9slrLsAO1XpuXJ3ougnFspQKDTQt2PC4nQD3iuYm/csftLQZiBll 76OqLhrwrdOSYyqMwKsxD84n0wYgxY4ipjBBluH3GFDNCISN92BCjS0pGsZlD0A/YZ AveBHm7vWw0Pw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4gpmqB3QSPz6txY; Mon, 29 Jun 2026 15:10:30 +0200 (CEST) From: Markus Probst Date: Mon, 29 Jun 2026 13:10:32 +0000 Subject: [PATCH v21 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: <20260629-rust_leds-v21-3-4f0f19579db5@posteo.de> References: <20260629-rust_leds-v21-0-4f0f19579db5@posteo.de> In-Reply-To: <20260629-rust_leds-v21-0-4f0f19579db5@posteo.de> To: Lee Jones , Pavel Machek , Greg Kroah-Hartman , Dave Ertman , Leon Romanovsky , Miguel Ojeda , Alex Gaynor , 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?= , Boqun Feng , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , =?utf-8?q?Onur_=C3=96zkan?= , Ira Weiny , Boqun Feng 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=23219; i=markus.probst@posteo.de; h=from:subject:message-id; bh=RSsYvswDNkPUr03lsAvodf/Y/Pvm8t3EpULz4JWrGcQ=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBqQm6/bXNM25T2PKst3kQl++guFi9G/ReSZk2lf XaMVOrhVr2JAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCakJuvxsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQNHYf+OetQ9KQfA//QIiwUd3oZ42e1oIcTd0TWlx0A2sU33x D9Em3G6wEerrfSzii6+mHLe8iQu5ZcAfCUy/j71Gb83gCjKB7XgCL6+9xTdFBmVQwcpDDJu+X/J /9hp9kAA7nJFlOzVKb7GPvhwwhH9aF9wLqOS+//qz+bGxzNqt7Ly0etgIJ/47bgkVu4upsp9GB4 1M4b7wfegv9OMLiuhtrQbZzDINfpmnXq1gdjSVkm3BP/UwYemOHk+kuO2tKz2dBXjV1xtzmWGpw Slm8h1ZUP9j2iynFQv2An9GcV8TFsotPNzjowa6CumHOIVJgCEZHbpiCrXZfVvS+5/vsktbxVX5 Zy3dh9Z0CUYelMWzVFy2hVENARC0nhc/L0HnvFAs1LrZsiZk90IrNKgzlT05oSZzHwlwdxRsnNp 7x7ADwc7rW7AXRP5O0EXcD78/PEmCVcnwX1dVRSfuVWxQnCB9w78WWp6M3YsmMXbhNJMteYuEDg tbeCHY4U3w1NBasyskkrs2u5Z+nRM7YTa/JvyPrX2YQLIRdQZJ1jxdkMnakb2XFVKYlzIUS003k rjcPO1RV8jSZn1x4NQ9Zcryzkr6zlIw+JG70k6TKlprfQuo5P4gcixfWoMyYzwMFnpdlZP2FGin w0oJvY3xh1uCApBULOkiGnrfl6hewETFDdih0rwl+n4vt54V9GYI= X-Developer-Key: i=markus.probst@posteo.de; a=openpgp; fpr=827418C4F4AC58E77230C47334761FF8E7AD43D2 Autocrypt: addr=markus.probst@posteo.de; prefer-encrypt=mutual; keydata=xsFNBGiDvXgBEADAXUceKafpl46S35UmDh2wRvvx+UfZbcTjeQOlSwKP7YVJ4JOZrVs93qReNLkO WguIqPBxR9blQ4nyYrqSCV+MMw/3ifyXIm6Pw2YRUDg+WTEOjTixRCoWDgUj1nOsvJ9tVAm76Ww+ /pAnepVRafMID0rqEfD9oGv1YrfpeFJhyE2zUw3SyyNLIKWD6QeLRhKQRbSnsXhGLFBXCqt9k5JA RhgQof9zvztcCVlT5KVvuyfC4H+HzeGmu9201BVyihJwKdcKPq+n/aY5FUVxNTgtI9f8wIbmfAja oT1pjXSp+dszakA98fhONM98pOq723o/1ZGMZukyXFfsDGtA3BB79HoopHKujLGWAGskzClwTjRQ xBqxh/U/lL1pc+0xPWikTNCmtziCOvv0KA0arDOMQlyFvImzX6oGVgE4ksKQYbMZ3Ikw6L1Rv1J+ FvN0aNwOKgL2ztBRYscUGcQvA0Zo1fGCAn/BLEJvQYShWKeKqjyncVGoXFsz2AcuFKe1pwETSsN6 OZncjy32e4ktgs07cWBfx0v62b8md36jau+B6RVnnodaA8++oXl3FRwiEW8XfXWIjy4umIv93tb8 8ekYsfOfWkTSewZYXGoqe4RtK80ulMHb/dh2FZQIFyRdN4HOmB4FYO5sEYFr9YjHLmDkrUgNodJC XCeMe4BO4iaxUQARAQABzRdtYXJrdXMucHJvYnN0QHBvc3Rlby5kZcLBkQQTAQgAOxYhBIJ0GMT0 rFjncjDEczR2H/jnrUPSBQJog714AhsDBQsJCAcCAiICBhUKCQgLAgQWAgMBAh4HAheAAAoJEDR2 H/jnrUPSgdkQAISaTk2D345ehXEkn5z2yUEjaVjHIE7ziqRaOgn/QanCgeTUinIv6L6QXUFvvIfH 1OLPwQ1hfvEg9NnNLyFezWSy6jvoVBTIPqicD/r3FkithnQ1IDkdSjrarPMxJkvuh3l7XZHo49GV HQ8i5zh5w4YISrcEtE99lJisvni2Jqx7we5tey9voQFDyM8jxlSWv3pmoUTCtBkX/eKHJXosgsuS B4TGDCVPOjla/emI5c9MhMG7O4WEEmoSdPbmraPw66YZD6uLyhV4DPHbiDWRzXWnClHSyjB9rky9 lausFxogvu4l9H+KDsXIadNDWdLdu1/enS/wDd9zh5S78rY2jeXaG4mnf4seEKamZ7KQ6FIHrcyP ezdDzssPQcTQcGRMQzCn6wP3tlGk7rsfmyHMlFqdRoNNv+ZER/OkmZFPW655zRfbMi0vtrqK2Awm 9ggobb1oktfd9PPNXMUY+DNVlgR2G7jLnenSoQausLUm0pHoNE8TWFv851Y6SOYnvn488sP1Tki5 F3rKwclawQFHUXTCQw+QSh9ay8xgnNZfH+u9NY7w3gPoeKBOAFcBc2BtzcgekeWS8qgEmm2/oNFV G0ivPQbRx8FjRKbuF7g3YhgNZZ0ac8FneuUtJ2PkSIFTZhaAiC0utvxk0ndmWFiW4acEkMZGrLaM L2zWNjrqwsD2zsFNBGiDvXgBEADCXQy1n7wjRxG12DOVADawjghKcG+5LtEf31WftHKLFbp/HArj BhkT6mj+CCI1ClqY+FYU5CK/s0ScMfLxRGLZ0Ktzawb78vOgBVFT3yB1yWBTewsAXdqNqRooaUNo 8cG/NNJLjhccH/7PO/FWX5qftOVUJ/AIsAhKQJ18Tc8Ik73v427EDxuKb9mTAnYQFA3Ev3hAiVbO 6Rv39amVOfJ8sqwiSUGidj2Fctg2aB5JbeMln0KCUbTD1LhEFepeKypfofAXQbGwaCjAhmkWy/q3 IT1mUrPxOngbxdRoOx1tGUC0HCMUW1sFaJgQPMmDcR0JGPOpgsKnitsSnN7ShcCr1buel7vLnUMD +TAZ5opdoF6HjAvAnBQaijtK6minkrM0seNXnCg0KkV8xhMNa6zCs1rq4GgjNLJue2EmuyHooHA4 7JMoLVHcxVeuNTp6K2+XRx0Pk4e2Lj8IVy9yEYyrywEOC5XRW37KJjsiOAsumi1rkvM7QREWgUDe Xs0+RpxI3QrrANh71fLMRo7LKRF3Gvw13NVCCC9ea20P4PwhgWKStkwO2NO+YJsAoS1QycMi/vKu 0EHhknYXamaSV50oZzHKmX56vEeJHTcngrM8R1SwJCYopCx9gkz90bTVYlitJa5hloWTYeMD7FNj Y6jfVSzgM/K4gMgUNDW/PPGeMwARAQABwsF2BBgBCAAgFiEEgnQYxPSsWOdyMMRzNHYf+OetQ9IF AmiDvXgCGwwACgkQNHYf+OetQ9LHDBAAhk+ab8+WrbS/b1/gYW3q1KDiXU719nCtfkUVXKidW5Ec Idlr5HGt8ilLoxSWT2Zi368iHCXS0WenGgPwlv8ifvB7TOZiiTDZROZkXjEBmU4nYjJ7GymawpWv oQwjMsPuq6ysbzWtOZ7eILx7cI0FjQeJ/Q2baRJub0uAZNwBOxCkAS6lpk5Fntd2u8CWmDQo4SYp xeuQ+pwkp0yEP30RhN2BO2DXiBEGSZSYh+ioGbCHQPIV3iVj0h6lcCPOqopZqyeCfigeacBI0nvN jHWz/spzF3+4OS+3RJvoHtAQmProxyGib8iVsTxgZO3UUi4TSODeEt0i0kHSPY4sCciOyXfAyYoD DFqhRjOEwBBxhr+scU4C1T2AflozvDwq3VSONjrKJUkhd8+WsdXxMdPFgBQuiKKwUy11mz6KQfcR wmDehF3UaUoxa+YIhWPbKmycxuX/D8SvnqavzAeAL1OcRbEI/HsoroVlEFbBRNBZLJUlnTPs8ZcU 4+8rq5YX1GUrJL3jf6SAfSgO7UdkEET3PdcKFYtS+ruV1Cp5V0q4kCfI5jk25iiz8grM2wOzVSsc l1mEkhiEPH87HP0whhb544iioSnumd3HJKL7dzhRegsMizatupp8D65A2JziW0WKopa1iw9fti3A aBeNN4ijKZchBXHPgVx+YtWRHfcm4l8= OpenPGP: url=https://posteo.de/keys/markus.probst@posteo.de.asc; 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::MultiColorDevice` - a safe wrapper around `led_classdev_mc` * `led::DeviceBuilder::build_multicolor` - a function to register a new multicolor led class device Signed-off-by: Markus Probst --- rust/bindings/bindings_helper.h | 1 + rust/kernel/led.rs | 34 ++- rust/kernel/led/multicolor.rs | 460 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 494 insertions(+), 1 deletion(-) diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 1124785e210b..821f539e597e 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -68,6 +68,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs index 6ee337008db7..4540c4e5c9d7 100644 --- a/rust/kernel/led.rs +++ b/rust/kernel/led.rs @@ -30,8 +30,16 @@ types::Opaque, // }; +#[cfg(CONFIG_LEDS_CLASS_MULTICOLOR)] +mod multicolor; mod normal; +#[cfg(CONFIG_LEDS_CLASS_MULTICOLOR)] +pub use multicolor::{ + MultiColor, + MultiColorDevice, + MultiColorSubLed, // +}; pub use normal::{ Device, Normal, // @@ -255,7 +263,24 @@ pub enum Color { Violet = bindings::LED_COLOR_ID_VIOLET, Yellow = bindings::LED_COLOR_ID_YELLOW, Ir = bindings::LED_COLOR_ID_IR, + #[cfg_attr( + CONFIG_LEDS_CLASS_MULTICOLOR, + doc = "Use this color for a [`MultiColor`] led." + )] + #[cfg_attr( + not(CONFIG_LEDS_CLASS_MULTICOLOR), + doc = "Use this color for a `MultiColor` led." + )] + /// If the led supports RGB, use [`Color::Rgb`] instead. Multi = bindings::LED_COLOR_ID_MULTI, + #[cfg_attr( + CONFIG_LEDS_CLASS_MULTICOLOR, + doc = "Use this color for a [`MultiColor`] led with rgb support." + )] + #[cfg_attr( + not(CONFIG_LEDS_CLASS_MULTICOLOR), + doc = "Use this color for a `MultiColor` led with rgb support." + )] Rgb = bindings::LED_COLOR_ID_RGB, Purple = bindings::LED_COLOR_ID_PURPLE, Orange = bindings::LED_COLOR_ID_ORANGE, @@ -296,7 +321,14 @@ 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::Sealed { /// The class device for the led mode. type Device<'bound, T: LedOps + 'bound>; diff --git a/rust/kernel/led/multicolor.rs b/rust/kernel/led/multicolor.rs new file mode 100644 index 000000000000..2c55140dd37e --- /dev/null +++ b/rust/kernel/led/multicolor.rs @@ -0,0 +1,460 @@ +// 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 core::{ + cell::UnsafeCell, + num::NonZero, + ptr, // +}; + +use crate::types::ScopeGuard; + +use super::*; + +/// The led mode for the `struct led_classdev_mc`. Leds with this mode can have multiple colors. +pub enum MultiColor {} +impl Mode for MultiColor { + type Device<'bound, T: LedOps + 'bound> = MultiColorDevice<'bound, T>; +} +impl private::Sealed for MultiColor {} + +/// The multicolor sub led info representation. +/// +/// This structure represents the Rust abstraction for a C `struct mc_subled`. +#[repr(C)] +#[derive(Debug)] +#[non_exhaustive] +pub struct MultiColorSubLed { + /// The color of the sub led + pub color: Color, + brightness: UnsafeCell, + intensity: UnsafeCell, + /// The maximum supported intensity value. + /// + /// If None the maximum intensity equals to [`LedOps::MAX_BRIGHTNESS`]. + pub max_intensity: Option>, + /// Arbitrary data for the driver to store. + pub channel: u32, +} + +// SAFETY: `MultiColorSubLed` can be shared among threads. +unsafe impl Sync for MultiColorSubLed {} + +impl Clone for MultiColorSubLed { + fn clone(&self) -> Self { + Self { + color: self.color, + brightness: self.brightness().into(), + intensity: self.intensity().into(), + max_intensity: self.max_intensity, + channel: self.channel, + } + } +} + +// 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: UnsafeCell::new(0), + intensity: UnsafeCell::new(0), + max_intensity: None, + channel: 0, + }; + let c_zeroed = bindings::mc_subled { + color_index: 0, + brightness: 0, + intensity: 0, + max_intensity: 0, + channel: 0, + }; + + assert!(offset_of!(MultiColorSubLed, color) == offset_of!(bindings::mc_subled, color_index)); + assert!( + offset_of!(MultiColorSubLed, brightness) == offset_of!(bindings::mc_subled, brightness) + ); + assert!(offset_of!(MultiColorSubLed, intensity) == offset_of!(bindings::mc_subled, intensity)); + assert!( + offset_of!(MultiColorSubLed, max_intensity) + == offset_of!(bindings::mc_subled, max_intensity) + ); + assert!(offset_of!(MultiColorSubLed, channel) == offset_of!(bindings::mc_subled, channel)); + + assert_same_type(&0u32, &c_zeroed.color_index); + assert_same_type(&rust_zeroed.brightness.into_inner(), &c_zeroed.brightness); + assert_same_type(&rust_zeroed.intensity.into_inner(), &c_zeroed.intensity); + assert!(size_of_val(&rust_zeroed.max_intensity) == size_of_val(&c_zeroed.max_intensity)); + assert_same_type(&rust_zeroed.channel, &c_zeroed.channel); + + assert!(size_of::() == size_of::()); +}; + +impl MultiColorSubLed { + /// Create a new multicolor sub led info. + #[inline] + pub const fn new(color: Color) -> Self { + Self { + color, + brightness: UnsafeCell::new(0), + intensity: UnsafeCell::new(0), + max_intensity: None, + channel: 0, + } + } + + /// Set arbitrary data for the driver. + #[inline] + pub const fn channel(mut self, channel: u32) -> Self { + self.channel = channel; + self + } + + /// Set the initial intensity of the subled. + #[inline] + pub const fn initial_intensity(mut self, intensity: u32) -> Self { + self.intensity = UnsafeCell::new(intensity); + self + } + + /// Set the maximum supported intensity of the subled. + #[inline] + pub const fn max_intensity(mut self, max_intensity: NonZero) -> Self { + self.max_intensity = Some(max_intensity); + self + } + + /// The intensity of the sub led. + #[inline] + pub const fn intensity(&self) -> u32 { + // SAFETY: + // - `self.intensity.get()` is a valid pointer to `u32`. + // - We don't have exclusive or immutable access to `self.intensity`, + // but the alignment should prevent "load tearing". + unsafe { *self.intensity.get() } + } + + /// The brightness of the sub led. + #[inline] + pub const fn brightness(&self) -> u32 { + // SAFETY: + // - `self.brightness.get()` is a valid pointer to `u32`. + // - We don't have exclusive or immutable access to `self.brightness`, + // but the alignment should prevent "load tearing". + unsafe { *self.brightness.get() } + } +} + +/// The multicolor led class device representation. +/// +/// This structure represents the Rust abstraction for a multicolor led class device. +#[pin_data(PinnedDrop)] +pub struct MultiColorDevice<'bound, T: LedOps + 'bound> { + #[pin] + ops: T, + #[pin] + classdev: Opaque, + _p: PhantomData<&'bound ()>, +} + +impl<'a, S: DeviceBuilderState> DeviceBuilder<'a, S> { + /// Registers a new [`MulticolorDevice`]. + pub fn build_multicolor<'bound: 'a, T: LedOps + 'bound>( + self, + parent: &'bound T::Bus, + ops: impl PinInit + 'a, + subleds: &'a [MultiColorSubLed], + ) -> impl PinInit, Error> + 'a { + const_assert!(T::MAX_BRIGHTNESS <= i32::MAX.unsigned_abs() || !T::HAS_BRIGHTNESS_GET); + + try_pin_init!(MultiColorDevice { + ops <- ops, + classdev <- Opaque::try_ffi_init(|ptr: *mut bindings::led_classdev_mc| { + let mut colors = [false; bindings::LED_COLOR_ID_MAX as usize]; + for subled in subleds { + if colors[subled.color as usize] { + dev_err!(parent.as_ref(), "duplicate color in multicolor led\n"); + return Err(EINVAL); + } + colors[subled.color as usize] = true; + } + let subleds_box = KBox::pin_slice( + |index| Ok::<_, Error>(subleds[index].clone()), + subleds.len(), + GFP_KERNEL, + )?; + let subleds_box_raw = KBox::into_raw(Pin::into_inner(subleds_box)); + + let subled_guard = ScopeGuard::new(|| { + // SAFETY: `subleds_box_raw` is guaranteed to be a valid pointer to + // `[MultiColorSubLed]`. + drop(unsafe { >::from_raw(subleds_box_raw) }); + }); + + // SAFETY: `try_ffi_init` guarantees that `ptr` is valid for write. + // `led_classdev_mc` gets fully initialized in-place by + // `led_classdev_multicolor_register_ext` including `mutex` and `list_head`. + unsafe { + ptr.write(bindings::led_classdev_mc { + led_cdev: bindings::led_classdev { + brightness_set: (!T::BLOCKING) + .then_some(Adapter::::brightness_set_callback), + brightness_set_blocking: T::BLOCKING + .then_some(Adapter::::brightness_set_blocking_callback), + brightness_get: T::HAS_BRIGHTNESS_GET + .then_some(Adapter::::brightness_get_callback), + blink_set: T::HAS_BLINK_SET.then_some(Adapter::::blink_set_callback), + max_brightness: T::MAX_BRIGHTNESS, + brightness: self.initial_brightness, + color: self.color as u32, + name: self.name.map_or(core::ptr::null(), CStrExt::as_char_ptr), + ..bindings::led_classdev::default() + }, + num_colors: u32::try_from(subleds_box_raw.len())?, + // CAST: The safeguards in the const block ensure that + // `MultiColorSubLed` has an identical layout to `mc_subled`. + subled_info: subleds_box_raw.cast::(), + }) + }; + + let mut init_data = bindings::led_init_data { + fwnode: self + .fwnode + .as_ref() + .map_or(core::ptr::null_mut(), |fwnode| fwnode.as_raw()), + default_label: core::ptr::null(), + devicename: self + .devicename + .map_or(core::ptr::null(), CStrExt::as_char_ptr), + devname_mandatory: self.devname_mandatory, + }; + + // SAFETY: + // - `parent.as_ref().as_raw()` is guaranteed to be a pointer to a valid + // `device`. + // - `ptr` is guaranteed to be a pointer to an initialized `led_classdev_mc`. + to_result(unsafe { + bindings::led_classdev_multicolor_register_ext( + parent.as_ref().as_raw(), + ptr, + if self.name.is_none() { + &raw mut init_data + } else { + core::ptr::null_mut() + }, + ) + })?; + + subled_guard.dismiss(); + + core::mem::forget(self.fwnode); // keep the reference count incremented + + Ok::<_, Error>(()) + }), + _p: PhantomData, + }) + } +} + +impl<'bound, T: LedOps + 'bound> MultiColorDevice<'bound, T> { + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded within a + /// `led::MultiColorDevice`. + #[inline] + unsafe fn from_raw<'a>(led_cdev: *mut bindings::led_classdev) -> &'a Self { + // SAFETY: The function's contract guarantees that `led_cdev` points to a `led_classdev` + // field embedded within a valid `led::MultiColorDevice`. `container_of!` can therefore + // safely calculate the address of the containing struct. + let led_mc_cdev = unsafe { container_of!(led_cdev, bindings::led_classdev_mc, led_cdev) }; + + // SAFETY: It is guaranteed that `led_mc_cdev` points to a `led_classdev_mc` + // field embedded within a valid `led::MultiColorDevice`. `container_of!` can therefore + // safely calculate the address of the containing struct. + unsafe { &*container_of!(Opaque::cast_from(led_mc_cdev), Self, classdev) } + } + + #[inline] + fn parent(&self) -> &'bound device::Device { + // SAFETY: `self.classdev.get()` is guaranteed to be a valid pointer to `led_classdev_mc`. + unsafe { device::Device::from_raw((*(*self.classdev.get()).led_cdev.dev).parent) } + } + + /// Returns the subleds passed to [`Device::new_multicolor`]. + #[inline] + 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::(), + // CAST: It is guaranteed that `num_colors` fits into an `usize`. + raw.num_colors as usize, + ) + } + } +} + +// SAFETY: A `led::MultiColorDevice` can be unregistered from any thread. +unsafe impl<'bound, T: LedOps + 'bound + Send> Send + for MultiColorDevice<'bound, T> +{ +} + +// SAFETY: `led::MultiColorDevice` can be shared among threads because all methods of `led::Device` +// are thread safe. +unsafe impl<'bound, T: LedOps + 'bound + Sync> Sync + for MultiColorDevice<'bound, T> +{ +} + +struct Adapter> { + _p: PhantomData, +} + +impl> Adapter { + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded within a + /// `led::MultiColorDevice`. + /// This function is called on setting the brightness of a led. + unsafe extern "C" fn brightness_set_callback( + led_cdev: *mut bindings::led_classdev, + brightness: u32, + ) { + // SAFETY: The function's contract guarantees that `led_cdev` is a valid pointer to a + // `led_classdev` embedded within a `led::MultiColorDevice`. + let classdev = unsafe { MultiColorDevice::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T::Bus`. + let parent = unsafe { T::Bus::from_device(classdev.parent()) }; + + // SAFETY: `classdev.classdev.get()` is guaranteed to be a pointer to a valid + // `led_classdev_mc`. + unsafe { bindings::led_mc_calc_color_components(classdev.classdev.get(), brightness) }; + + let _ = classdev.ops.brightness_set(parent, classdev, brightness); + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded within a + /// `led::MultiColorDevice`. + /// This function is called on setting the brightness of a led immediately. + unsafe extern "C" fn brightness_set_blocking_callback( + led_cdev: *mut bindings::led_classdev, + brightness: u32, + ) -> i32 { + from_result(|| { + // SAFETY: The function's contract guarantees that `led_cdev` is a valid pointer to a + // `led_classdev` embedded within a `led::MultiColorDevice`. + let classdev = unsafe { MultiColorDevice::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T::Bus`. + let parent = unsafe { T::Bus::from_device(classdev.parent()) }; + + // SAFETY: `classdev.classdev.get()` is guaranteed to be a pointer to a valid + // `led_classdev_mc`. + unsafe { bindings::led_mc_calc_color_components(classdev.classdev.get(), brightness) }; + + classdev.ops.brightness_set(parent, classdev, brightness)?; + Ok(0) + }) + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded within a + /// `led::MultiColorDevice`. + /// This function is called on getting the brightness of a led. + unsafe extern "C" fn brightness_get_callback(led_cdev: *mut bindings::led_classdev) -> u32 { + // SAFETY: The function's contract guarantees that `led_cdev` is a valid pointer to a + // `led_classdev` embedded within a `led::MultiColorDevice`. + let classdev = unsafe { MultiColorDevice::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T::Bus`. + let parent = unsafe { T::Bus::from_device(classdev.parent()) }; + + // CAST: Resulting value will be casted back to i32 in the led subsystem. + from_result(|| { + classdev + .ops + .brightness_get(parent, classdev) + .inspect(|val| debug_assert!(*val <= T::MAX_BRIGHTNESS)) + .and_then(|val| Ok(i32::try_from(val)?)) + }) as u32 + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded within a + /// `led::MultiColorDevice`. + /// `delay_on` and `delay_off` must be valid pointers to `usize` and have + /// exclusive access for the period of this function. + /// This function is called on enabling hardware accelerated blinking. + unsafe extern "C" fn blink_set_callback( + led_cdev: *mut bindings::led_classdev, + delay_on: *mut usize, + delay_off: *mut usize, + ) -> i32 { + from_result(|| { + // SAFETY: The function's contract guarantees that `led_cdev` is a valid pointer to a + // `led_classdev` embedded within a `led::MultiColorDevice`. + let classdev = unsafe { MultiColorDevice::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T::Bus`. + let parent = unsafe { T::Bus::from_device(classdev.parent()) }; + + classdev.ops.blink_set( + parent, + classdev, + // SAFETY: The function's contract guarantees that `delay_on` points to a `usize` + // and is exclusive for the period of this function. + unsafe { &mut *delay_on }, + // SAFETY: The function's contract guarantees that `delay_off` points to a `usize` + // and is exclusive for the period of this function. + unsafe { &mut *delay_off }, + )?; + Ok(0) + }) + } +} + +#[pinned_drop] +impl<'bound, T: LedOps + 'bound> PinnedDrop for MultiColorDevice<'bound, T> { + fn drop(self: Pin<&mut Self>) { + let raw = self.classdev.get(); + // SAFETY: The existence of `self` guarantees that `self.classdev.get()` is a pointer to a + // valid `led_classdev_mc`. + let dev: &device::Device = unsafe { device::Device::from_raw((*raw).led_cdev.dev) }; + + let _fwnode = dev + .fwnode() + // SAFETY: the reference count of `fwnode` has previously been + // incremented in `led::DeviceBuilder::build_multicolor`. + .map(|fwnode| unsafe { ARef::from_raw(NonNull::from(fwnode)) }); + + // SAFETY: The existence of `self` guarantees that `self.classdev` has previously been + // successfully registered with `led_classdev_multicolor_register_ext`. + unsafe { bindings::led_classdev_multicolor_unregister(raw) }; + + // SAFETY: `raw` is guaranteed to be a valid pointer to `led_classdev_mc`. + let led_cdev = unsafe { &*raw }; + + // SAFETY: `led_cdev.subled_info` is guaranteed to be a valid pointer to + // `[MultiColorSubLed]` with length of `led_cdev.num_colors`. + // See `led::DeviceBuilder::build_multicolor`. + drop(unsafe { + KBox::from_raw(ptr::slice_from_raw_parts_mut( + led_cdev.subled_info.cast::(), + // CAST: `num_colors` was originally converted from a `usize` in + // `DeviceBuilder::build_multicolor`. Thus it is guaranteed that + // `num_colors` fits into an usize. + led_cdev.num_colors as usize, + )) + }); + } +} -- 2.53.0