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 A518C3CBE7A for ; Fri, 1 May 2026 14:36:10 +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=1777646173; cv=none; b=LALxJxGo4EmWzF+rIvXzzAYIH6hSW6TsOflL2o+P7TufO5KAmfB3Ru5/1KOy1L9nfqjeOr5qSKpMRjvahSvog4uv2kSE55ObBmIaPE73BzpV1GnjqvOLIJTmg99mf3t0Ok1wPpRW2KqXeoIcyTUIvTp4+7r/bMaAMKrKxOa79xw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777646173; c=relaxed/simple; bh=rzGXoI2lg0taXDUNyHk1melfTjthRWRUCeSLCwTMaKg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=FeLAjYnijqwO3oHodt0fA6pVEhi2HDkfukpQ8MA25VH5ldcJQ+Zh04a5irDvjC5TleEZlJyQ3cM2cHNSkJ+dFpvIAsKJ/e68S8e1Cvxi5g9Vpj6GbzSRB1yQtHJUb+DMU96sGiLw0wHNp/X/9wQ22FJ5nsazLfBiVJCY2cHpNMs= 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=M8tmysNL; 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="M8tmysNL" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 1AA16240101 for ; Fri, 1 May 2026 16:36:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1777646168; bh=v3LUrR3RpK07MkYZKRXUdazgsV9G4HrIRZS7/gPztGs=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=M8tmysNLkNObYwWM3l73bZjt8GFxda4I4pPJfJSN7DSUshhttMbA9kQ9++KOCQ6hP +JzJMaG49o2vHLpAA6cl4VB4EfUjTyr/PWH5FsMl7a7DapgH5TcUYqbHuER13cSD6A 5Lo5a2C0LI2QDkD4pnJ1OYEcEx/JXufgQZNdpnFw5CCDJGPkW1cOTwD1kpNkZxBygl 7e2mzuYl7FTsBcisEQCIoqC90dy7qccGa7av86hHCbxcUyyoy5R9WQQs2jAX2XNIf5 FnR8RlIA9ePiZRJofjLVxv7NHZBy5cmNwLvUFIkJCFv2tsT/oxFiBS0ep5DrGzslFP ZiwnzU0tmI7CQ== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4g6YW96tvbz9rxK; Fri, 1 May 2026 16:36:05 +0200 (CEST) From: Markus Probst Date: Fri, 01 May 2026 14:36:07 +0000 Subject: [PATCH v16 3/3] rust: leds: add multicolor classdev abstractions Precedence: bulk X-Mailing-List: linux-kernel@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: <20260501-rust_leds-v16-3-9f329fdedcd9@posteo.de> References: <20260501-rust_leds-v16-0-9f329fdedcd9@posteo.de> In-Reply-To: <20260501-rust_leds-v16-0-9f329fdedcd9@posteo.de> To: Lee Jones , Pavel Machek , Greg Kroah-Hartman , Dave Ertman , Ira Weiny , 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 , 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=21258; i=markus.probst@posteo.de; h=from:subject:message-id; bh=rzGXoI2lg0taXDUNyHk1melfTjthRWRUCeSLCwTMaKg=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBp9LpRQrtFm3cLfxIKTkaC1hm7Vr66WghupyBAo zi6rYv+gIKJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCafS6URsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQNHYf+OetQ9IB9hAAjKgTjPEqqsz7oNKzOE2gB+4lTyGWkm3 Yh6+Rse3+n8/J+wWgrRmvWbqzDTiE8kkJ+LzwUgXjWyi3IE6UwmjMY7Srl+jxnhTGLMUXze1iOz sDpEBlWmR/OM4wXuQ02cRPsdCpo1AqkCFSbwGXlnMvWTuw9Szn8k/PbhvQf11hhcASbIJ4AKNI0 BH/qkU5NBgj2bedivUsworVd8GykDg0A/BYbWpwFl+RVRMh6MYzgnxfNvKrZr3Rwukgz0p9nuWK IWEzXPdKmgI828bNnu5Ocdhcw7JITN80KagLvYQBl1MnXmITt/Hd4SxIKm9DS8i6sOqPaJzVOe0 CJoBF+v6wd/7om1CnQkIu/GzwD0YyxmVSEotds5PUNhC+CX3Rn7xh0wHizcLMNukj3vV70E4h4T BRk2zdBnmBVEQ8KIwz6Ema1m23tn7sUOESlMpZMJ5yT1qLbQGEmNqILEVt1w5ulf0dpsYVTtKdP EzIEKlXiDe1N9vlJXv0LsqCbZ/YLufzsZ1tdjaab8G8h80oGsoPycwExyiHPwFsYrpZfu/9+siB l+BgGDCICSoqNucSqSX2lRUqic0n9lQTkclViyI36UK9wRs3QhDe2Ug6sB13larYREz4GcxdTko zMRD+7X/qNwbo66Jo9te1w2LsFkpcCf8+HItFHGtxuw1ZVwYTEe8= 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::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 | 405 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 439 insertions(+), 1 deletion(-) diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 446dbeaf0866..17b5461453e0 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -67,6 +67,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs index 5ddfee47f911..61202f85b218 100644 --- a/rust/kernel/led.rs +++ b/rust/kernel/led.rs @@ -31,8 +31,16 @@ 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, // @@ -267,7 +275,24 @@ 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, @@ -308,7 +333,14 @@ 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>; diff --git a/rust/kernel/led/multicolor.rs b/rust/kernel/led/multicolor.rs new file mode 100644 index 000000000000..900ef050d2d3 --- /dev/null +++ b/rust/kernel/led/multicolor.rs @@ -0,0 +1,405 @@ +// 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, + 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> = MultiColorDevice; +} +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(Copy, Clone, Debug)] +#[non_exhaustive] +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, +} + +// 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, + }; + 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. + #[inline] + pub const fn new(color: Color) -> Self { + Self { + color, + brightness: 0, + intensity: 0, + 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 = intensity; + self + } +} + +/// The multicolor led class device representation. +/// +/// This structure represents the Rust abstraction for a multicolor led class device. +#[pin_data(PinnedDrop)] +pub struct MultiColorDevice> { + #[pin] + ops: T, + #[pin] + classdev: Opaque, +} + +impl<'a, S: DeviceBuilderState> DeviceBuilder<'a, S> { + /// Registers a new [`MulticolorDevice`]. + pub fn build_multicolor>( + self, + parent: &'a 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); + + Devres::new( + parent.as_ref(), + try_pin_init!(MultiColorDevice { + ops <- ops, + classdev <- Opaque::try_ffi_init(|ptr: *mut bindings::led_classdev_mc| { + 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); + } + 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 subled_guard = ScopeGuard::new(|| { + // SAFETY: `subled_info` is guaranteed to be a valid array pointer to + // `mc_subled` with the length and capacity of `num_colors`. + drop(unsafe { KVec::from_raw_parts(subled_info, num_colors, num_colors) }); + }); + + // 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(num_colors)?, + // CAST: The safeguards in the const block ensure that + // `MultiColorSubLed` has an identical layout to `mc_subled`. + subled_info: subled_info.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>(()) + }), + }), + ) + } +} + +impl> MultiColorDevice { + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded within a + /// `led::MultiColorDevice`. + 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) -> &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 + Send> Send for MultiColorDevice {} + +// SAFETY: `led::MultiColorDevice` can be shared among threads because all methods of `led::Device` +// are thread safe. +unsafe impl + Sync> Sync for MultiColorDevice {} + +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> PinnedDrop for MultiColorDevice { + 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::Device::new`. + .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: `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::MulticolorDevice::new`. + drop(unsafe { + KVec::from_raw_parts( + led_cdev.subled_info, + led_cdev.num_colors as usize, + led_cdev.num_colors as usize, + ) + }); + } +} -- 2.53.0