From nobody Thu Apr 2 06:31:59 2026 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 CF1D238551A for ; Sun, 29 Mar 2026 17:22:41 +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=1774804965; cv=none; b=ZNHXe0/B8o7CB2aObr4boxwNY46VXG1iuYAPbyfhzBU8+EqoqZ2Bti/C6ajdvmywTk0SGfBXf8UMY1X2+xpd7Y8/wAygXahV3WWYv9FuRgNQHAcwkbh5TDetNMHjuMN9WwCtL2wVpwawOBIn1E0uwAmxwUpDutdtc0840/TYdSo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774804965; c=relaxed/simple; bh=QszL5h+d6vPaxLBAga1TpkkS1WCcrkx/YPuiAjd2t8g=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=S3R0SNvbykv/eatAGFkyAyiiy+Lo9JoIBR3+hKi6qOx3wdZ6yRF0TDvIziRoqRzzyX3nR3INlITrT9U+UlymFqjzWS79gCRBe2PIqGb4wgBYml48ej/MlWe8v2SsucGK02UGsmi1Pe/V8ai2qJpQ8IPvUFvQPxpw7T6dL1G5UKE= 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=KbB6Q7+J; 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="KbB6Q7+J" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 6CD46240104 for ; Sun, 29 Mar 2026 19:22:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1774804954; bh=ob5H5TwWOONtZftnmE6ueXsm851pZ2y3oWQVGbRPC0g=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=KbB6Q7+JjRjTDQZVROFU3hmk5sZJn0t2uEUurnG5OhyJOhPopUXYbEPRQiOoIMw7K Qz+P8I6SSU4fpbZ+Ygk+flItWb2dibHsshDveY+0kMOk/9rT6wu81zOL6sV4fpvp8d 1gGE6MZuY/WUum2POZz0tcJ7GewMDhzdywRkgpBEAvmL+UMAKIgMmPkn44YnrJKcSR vZvfQ3GvwXHagGFzp9rnuy3FnzdmApk4SMc3r/7Y7O+Y8iMIIRsKfnV13DS+fYJyxm hNS5ZWiaBcVcOYjP92GdS5n4MxMfAlBP2KczG9ap7T4DylfU3ZvzBezTUp82MXFrhE Ix9eQ6oqMveXQ== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4fkLmR45CZz9rxM; Sun, 29 Mar 2026 19:22:31 +0200 (CEST) From: Markus Probst Date: Sun, 29 Mar 2026 17:22:33 +0000 Subject: [PATCH v13 1/3] rust: leds: add basic led 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: quoted-printable Message-Id: <20260329-rust_leds-v13-1-21a599c5b2d1@posteo.de> References: <20260329-rust_leds-v13-0-21a599c5b2d1@posteo.de> In-Reply-To: <20260329-rust_leds-v13-0-21a599c5b2d1@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=20773; i=markus.probst@posteo.de; h=from:subject:message-id; bh=QszL5h+d6vPaxLBAga1TpkkS1WCcrkx/YPuiAjd2t8g=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBpyV/Q3y+ZJ9IcZnY2cwHcNQdOZ3thNMW/4BubX NVwMyG/iyeJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCaclf0BsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMSwyLDIACgkQNHYf+OetQ9L4ww//STc8JQLGSN7I12k0UTtRNKk/Rfo+HID +jpbL7trZY4fooaZ6+hczdM1yjGKo6sKgkBgU5L0r15dQv3Cijwzdos9SN8k7Ri3hOUk4e7xJvQ dHWEArwENU21RSNpXRnR/AyFFs7aU2lGfU0hgPDloS3vtW4qQPc3XvVg8pNrGXbH7gRE1DYjTG7 HDSoSHAc/aVWqhBOmn43ChSaHjC7E2MfjeBDu1qGuwTi7AEwGlm8xhdBPLkykeCtO1wOc3+XEyL xxCy8PWPVFRQM5HbKkZMAB7Xdt3vOk/Pnqm0ZEw2CWzkdmGaey0bjugytv2IIPz+lXi6HTduVQT 3I1msVNJnKhhZRn0G1nqxmt0ahST8MbRljnyaSRHsXzXu4kM7xsGIE0YJ8OPjMhVeCswXtyMUYR HWv/z+JQmLw5jjchcK3AgOE4TqAvmVS4i9/V5B8eMQNC5IuoKyXzJ85jDqcQuP7a4afocAYF3mU WKLuhAuNnPA7D5KC8W4d1WbsilPfnyLVnrJiwhj1lckeMqZFoutFyo7jJxr3CzXbFCzJiuaNRsZ EqAbrcWmXKTV6p16CyJp/i6em+h0qmU6B1qwafDC8k+ceKcer681avLseIr8D8//RffxcDBdFjC 3imfHA8S0e4txecyMSIB7KN6GW5bY/f2F0ajdmuatRTFvMS5nOLw= X-Developer-Key: i=markus.probst@posteo.de; 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preference=encrypt Implement the core abstractions needed for led class devices, including: * `led::LedOps` - the trait for handling leds, including `brightness_set`, `brightness_get` and `blink_set` * `led::DeviceBuilder` - the builder for the led class device * `led::Device` - a safe wrapper around `led_classdev` Signed-off-by: Markus Probst --- MAINTAINERS | 8 ++ rust/kernel/led.rs | 310 ++++++++++++++++++++++++++++++++++++++++++= ++++ rust/kernel/led/normal.rs | 223 +++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + 4 files changed, 542 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 7d10988cbc62..83b5a45de729 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14439,6 +14439,14 @@ F: drivers/leds/ F: include/dt-bindings/leds/ F: include/linux/leds.h =20 +LED SUBSYSTEM [RUST] +M: Markus Probst +L: linux-leds@vger.kernel.org +L: rust-for-linux@vger.kernel.org +S: Maintained +F: rust/kernel/led.rs +F: rust/kernel/led/ + LEGO MINDSTORMS EV3 R: David Lechner S: Maintained diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs new file mode 100644 index 000000000000..1fba512a804c --- /dev/null +++ b/rust/kernel/led.rs @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Abstractions for the leds driver model. +//! +//! C header: [`include/linux/leds.h`](srctree/include/linux/leds.h) + +use core::{ + marker::PhantomData, + mem::transmute, + ptr::NonNull, // +}; + +use crate::{ + container_of, + device::{ + self, + property::FwNode, + AsBusDevice, + Bound, // + }, + devres::Devres, + error::{ + from_result, + to_result, + VTABLE_DEFAULT_ERROR, // + }, + macros::vtable, + prelude::*, + str::CStrExt, + types::{ + ARef, + Opaque, // + }, // +}; + +mod normal; + +pub use normal::Device; + +/// The name of the led is determined by the driver. +pub enum Named {} +/// The name of the led is determined by its fwnode. +pub enum Unnamed {} + +/// How the name of the led should be determined. +pub trait DeviceBuilderState: private::Sealed {} + +impl DeviceBuilderState for Named {} +impl private::Sealed for Named {} +impl DeviceBuilderState for Unnamed {} +impl private::Sealed for Unnamed {} + +/// The builder to register a led class device. +/// +/// See [`LedOps`]. +pub struct DeviceBuilder<'a, S> { + fwnode: Option>, + name: Option<&'a CStr>, + devicename: Option<&'a CStr>, + devname_mandatory: bool, + initial_brightness: u32, + default_trigger: Option<&'a CStr>, + color: Color, + _p: PhantomData, +} + +impl DeviceBuilder<'static, S> { + /// Creates a new [`DeviceBuilder`]. + #[inline] + #[expect( + clippy::new_without_default, + reason =3D "no need and derive is prevented by S" + )] + pub fn new() -> Self { + Self { + fwnode: None, + name: None, + devicename: None, + devname_mandatory: false, + initial_brightness: 0, + default_trigger: None, + color: Color::default(), + _p: PhantomData, + } + } +} + +impl<'a> DeviceBuilder<'a, Unnamed> { + /// Sets the firmware node. + #[inline] + pub fn fwnode(self, fwnode: Option>) -> Self { + Self { fwnode, ..self } + } + + /// Sets the device name. + #[inline] + pub fn devicename(self, devicename: &'a CStr) -> Self { + Self { + devicename: Some(devicename), + ..self + } + } + + /// Sets if a device name is mandatory. + #[inline] + pub fn devicename_mandatory(self, mandatory: bool) -> Self { + Self { + devname_mandatory: mandatory, + ..self + } + } +} + +impl<'a, S: DeviceBuilderState> DeviceBuilder<'a, S> { + /// Sets the initial brightness value for the led. + /// + /// The default brightness is 0. + /// If [`LedOps::brightness_get`] is implemented, this value will be i= gnored. + #[inline] + pub fn initial_brightness(self, brightness: u32) -> Self { + Self { + initial_brightness: brightness, + ..self + } + } + + /// Set the default led trigger. + /// + /// This value can be overwritten by the "linux,default-trigger" fwnod= e property. + #[inline] + pub fn default_trigger(self, trigger: &'a CStr) -> Self { + Self { + default_trigger: Some(trigger), + ..self + } + } + + /// Sets the color of the led. + /// + /// This value can be overwritten by the "color" fwnode property. + #[inline] + pub fn color(self, color: Color) -> Self { + Self { color, ..self } + } +} + +impl<'a> DeviceBuilder<'a, Named> { + /// Sets the name of the led. + /// + /// Setting this will prevent the fwnode from being used and prevents = automatic name + /// composition. + #[inline] + pub fn name(self, name: &'a CStr) -> Self { + Self { + name: Some(name), + ..self + } + } +} + +/// Trait defining the operations for a LED driver. +/// +/// # Examples +/// ``` +/// use kernel::{ +/// device, +/// devres::Devres, +/// led, +/// macros::vtable, +/// platform, +/// prelude::*, // +/// }; +/// +/// struct MyLedOps; +/// +/// +/// #[vtable] +/// impl led::LedOps for MyLedOps { +/// type Bus =3D platform::Device; +/// const BLOCKING: bool =3D false; +/// const MAX_BRIGHTNESS: u32 =3D 255; +/// +/// fn brightness_set( +/// &self, +/// _dev: &platform::Device, +/// _classdev: &led::Device, +/// _brightness: u32 +/// ) -> Result<()> { +/// // Set the brightness for the led here +/// Ok(()) +/// } +/// } +/// +/// fn register_my_led( +/// parent: &platform::Device, +/// ) -> Result>>>> { +/// KBox::pin_init(led::DeviceBuilder::new() +/// .name(c"white:test") +/// .build( +/// parent, +/// Ok(MyLedOps), +/// ), GFP_KERNEL) +/// } +/// ``` +/// Led drivers must implement this trait in order to register and handle = a [`Device`]. +#[vtable] +pub trait LedOps: Send + 'static + Sized { + /// The bus device required by the implementation. + #[allow(private_bounds)] + type Bus: AsBusDevice; + + /// If set true, [`LedOps::brightness_set`] and [`LedOps::blink_set`] = must perform the + /// operation immediately. If set false, they must not sleep. + const BLOCKING: bool; + /// The max brightness level. + const MAX_BRIGHTNESS: u32; + + /// Sets the brightness level. + /// + /// See also [`LedOps::BLOCKING`]. + fn brightness_set( + &self, + dev: &Self::Bus, + classdev: &Device, + brightness: u32, + ) -> Result<()>; + + /// Gets the current brightness level. + fn brightness_get(&self, dev: &Self::Bus, classdev: &Device) -> = u32 { + let _ =3D (dev, classdev); + build_error!(VTABLE_DEFAULT_ERROR) + } + + /// Activates hardware accelerated blinking. + /// + /// delays are in milliseconds. If both are zero, a sensible default s= hould be chosen. + /// The caller should adjust the timings in that case and if it can't = match the values + /// specified exactly. Setting the brightness to 0 will disable the ha= rdware accelerated + /// blinking. + /// + /// See also [`LedOps::BLOCKING`]. + fn blink_set( + &self, + dev: &Self::Bus, + classdev: &Device, + delay_on: &mut usize, + delay_off: &mut usize, + ) -> Result<()> { + let _ =3D (dev, classdev, delay_on, delay_off); + build_error!(VTABLE_DEFAULT_ERROR) + } +} + +/// Led colors. +#[derive(Copy, Clone, Debug, Default)] +#[repr(u32)] +#[non_exhaustive] +#[expect( + missing_docs, + reason =3D "it shouldn't be necessary to document each color" +)] +pub enum Color { + #[default] + White =3D bindings::LED_COLOR_ID_WHITE, + Red =3D bindings::LED_COLOR_ID_RED, + Green =3D bindings::LED_COLOR_ID_GREEN, + Blue =3D bindings::LED_COLOR_ID_BLUE, + Amber =3D bindings::LED_COLOR_ID_AMBER, + Violet =3D bindings::LED_COLOR_ID_VIOLET, + Yellow =3D bindings::LED_COLOR_ID_YELLOW, + Ir =3D bindings::LED_COLOR_ID_IR, + Multi =3D bindings::LED_COLOR_ID_MULTI, + Rgb =3D bindings::LED_COLOR_ID_RGB, + Purple =3D bindings::LED_COLOR_ID_PURPLE, + Orange =3D bindings::LED_COLOR_ID_ORANGE, + Pink =3D bindings::LED_COLOR_ID_PINK, + Cyan =3D bindings::LED_COLOR_ID_CYAN, + Lime =3D bindings::LED_COLOR_ID_LIME, +} +static_assert!(bindings::LED_COLOR_ID_MAX =3D=3D 15); + +impl Color { + /// Name of the color. + pub fn as_c_str(self) -> &'static CStr { + // SAFETY: + // - `self as u8` is a valid led color id. + // - `led_get_color_name` always returns a valid C string pointer. + unsafe { CStr::from_char_ptr(bindings::led_get_color_name(self as = u8)) } + } +} + +impl TryFrom for Color { + type Error =3D Error; + + fn try_from(value: u32) -> core::result::Result { + if value < bindings::LED_COLOR_ID_MAX { + // SAFETY: + // - `Color` is represented as `u32` + // - the static_assert above guarantees that no additional col= or has been added + // - `value` is guaranteed to be in the color id range + Ok(unsafe { transmute::(value) }) + } else { + Err(EINVAL) + } + } +} + +mod private { + pub trait Sealed {} +} diff --git a/rust/kernel/led/normal.rs b/rust/kernel/led/normal.rs new file mode 100644 index 000000000000..bd239f186c64 --- /dev/null +++ b/rust/kernel/led/normal.rs @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Led mode for the `struct led_classdev`. +//! +//! C header: [`include/linux/leds.h`](srctree/include/linux/leds.h) + +use super::*; + +/// The led class device representation. +/// +/// This structure represents the Rust abstraction for a led class device. +#[pin_data(PinnedDrop)] +pub struct Device { + #[pin] + ops: T, + #[pin] + classdev: Opaque, +} + +impl<'a, S: DeviceBuilderState> DeviceBuilder<'a, S> { + /// Registers a new [`Device`]. + pub fn build( + self, + parent: &'a T::Bus, + ops: impl PinInit + 'a, + ) -> impl PinInit>, Error> + 'a { + Devres::new( + parent.as_ref(), + try_pin_init!(Device { + ops <- ops, + classdev <- Opaque::try_ffi_init(|ptr: *mut bindings::led_= classdev| { + // SAFETY: `try_ffi_init` guarantees that `ptr` is val= id for write. + // `led_classdev` gets fully initialized in-place by + // `led_classdev_register_ext` including `mutex` and `= list_head`. + unsafe { + ptr.write(bindings::led_classdev { + brightness_set: (!T::BLOCKING) + .then_some(Adapter::::brightness_set_ca= llback), + brightness_set_blocking: T::BLOCKING + .then_some(Adapter::::brightness_set_bl= ocking_callback), + brightness_get: T::HAS_BRIGHTNESS_GET + .then_some(Adapter::::brightness_get_ca= llback), + blink_set: T::HAS_BLINK_SET.then_some(Adapter:= :::blink_set_callback), + max_brightness: T::MAX_BRIGHTNESS, + brightness: self.initial_brightness, + default_trigger: self + .default_trigger + .map_or(core::ptr::null(), CStrExt::as_cha= r_ptr), + color: self.color as u32, + name: self.name.map_or(core::ptr::null(), CStr= Ext::as_char_ptr), + ..bindings::led_classdev::default() + }) + }; + + let mut init_data =3D 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_pt= r), + 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 initial= ized `led_classdev`. + to_result(unsafe { + bindings::led_classdev_register_ext( + parent.as_ref().as_raw(), + ptr, + if self.name.is_none() { + &raw mut init_data + } else { + core::ptr::null_mut() + }, + ) + })?; + + core::mem::forget(self.fwnode); // keep the reference = count incremented + + Ok::<_, Error>(()) + }), + }), + ) + } +} + +impl Device { + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + unsafe fn from_raw<'a>(led_cdev: *mut bindings::led_classdev) -> &'a S= elf { + // SAFETY: The function's contract guarantees that `led_cdev` poin= ts to a `led_classdev` + // field embedded within a valid `led::Device`. `container_of!` ca= n therefore + // safely calculate the address of the containing struct. + unsafe { &*container_of!(Opaque::cast_from(led_cdev), Self, classd= ev) } + } + + fn parent(&self) -> &device::Device { + // SAFETY: `self.classdev.get()` is guaranteed to be a valid point= er to `led_classdev`. + unsafe { device::Device::from_raw((*(*self.classdev.get()).dev).pa= rent) } + } +} + +// SAFETY: A `led::Device` can be unregistered from any thread. +unsafe impl Send for Device {} + +// SAFETY: `led::Device` can be shared among threads because all methods o= f `led::Device` +// are thread safe. +unsafe impl Sync for Device {} + +struct Adapter { + _p: PhantomData, +} + +impl Adapter { + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// 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::Device`. + let classdev =3D unsafe { Device::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T= ::Bus`. + let parent =3D unsafe { T::Bus::from_device(classdev.parent()) }; + + let _ =3D classdev.ops.brightness_set(parent, classdev, brightness= ); + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// This function is called on setting the brightness of a led immedia= tely. + 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::Device`. + let classdev =3D unsafe { Device::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained i= n `T::Bus`. + let parent =3D unsafe { T::Bus::from_device(classdev.parent())= }; + + classdev.ops.brightness_set(parent, classdev, brightness)?; + Ok(0) + }) + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// 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::Device`. + let classdev =3D unsafe { Device::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T= ::Bus`. + let parent =3D unsafe { T::Bus::from_device(classdev.parent()) }; + + classdev.ops.brightness_get(parent, classdev) + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// `delay_on` and `delay_off` must be valid pointers to `usize` and h= ave + /// 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::Device`. + let classdev =3D unsafe { Device::::from_raw(led_cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained i= n `T::Bus`. + let parent =3D 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 Device { + fn drop(self: Pin<&mut Self>) { + let raw =3D self.classdev.get(); + // SAFETY: The existence of `self` guarantees that `self.classdev.= get()` is a pointer to a + // valid `led_classdev`. + let dev: &device::Device =3D unsafe { device::Device::from_raw((*r= aw).dev) }; + + let _fwnode =3D 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_register_ext`. + unsafe { bindings::led_classdev_unregister(raw) }; + } +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index d93292d47420..d0e30d3733dd 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -115,6 +115,7 @@ pub mod jump_label; #[cfg(CONFIG_KUNIT)] pub mod kunit; +pub mod led; pub mod list; pub mod maple_tree; pub mod miscdevice; --=20 2.52.0 From nobody Thu Apr 2 06:31:59 2026 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 464CE374722 for ; Sun, 29 Mar 2026 17:22:47 +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=1774804972; cv=none; b=uR8QvuVOvEG4u3sT5njnKgQXeUeivG6MUYa489fk2KmZmVUpC4JKNr1tXIlVa07GH/nnN9iMDimZbMDsM75G0e2uKDBv4JqwagQ8QJ0LPftuNTh8LJ7N4hI1WYRIfHmd90ezRheVNiVVv2hLGk2tpoG7+uDl4DmvY1LW3DnDdsM= ARC-Message-Signature: i=1; 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charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260329-rust_leds-v13-2-21a599c5b2d1@posteo.de> References: <20260329-rust_leds-v13-0-21a599c5b2d1@posteo.de> In-Reply-To: <20260329-rust_leds-v13-0-21a599c5b2d1@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. 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Signed-off-by: Markus Probst --- rust/kernel/led.rs | 28 ++++++++++++++++++++++++---- rust/kernel/led/normal.rs | 24 ++++++++++++++++-------- 2 files changed, 40 insertions(+), 12 deletions(-) diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs index 1fba512a804c..5035563d68a3 100644 --- a/rust/kernel/led.rs +++ b/rust/kernel/led.rs @@ -35,7 +35,7 @@ =20 mod normal; =20 -pub use normal::Device; +pub use normal::{Device, Normal}; =20 /// The name of the led is determined by the driver. pub enum Named {} @@ -177,6 +177,7 @@ pub fn name(self, name: &'a CStr) -> Self { /// #[vtable] /// impl led::LedOps for MyLedOps { /// type Bus =3D platform::Device; +/// type Mode =3D led::Normal; /// const BLOCKING: bool =3D false; /// const MAX_BRIGHTNESS: u32 =3D 255; /// @@ -209,6 +210,11 @@ pub trait LedOps: Send + 'static + Sized { #[allow(private_bounds)] type Bus: AsBusDevice; =20 + /// The led mode to use. + /// + /// See [`Mode`]. + type Mode: Mode; + /// If set true, [`LedOps::brightness_set`] and [`LedOps::blink_set`] = must perform the /// operation immediately. If set false, they must not sleep. const BLOCKING: bool; @@ -221,12 +227,16 @@ pub trait LedOps: Send + 'static + Sized { fn brightness_set( &self, dev: &Self::Bus, - classdev: &Device, + classdev: &::Device, brightness: u32, ) -> Result<()>; =20 /// Gets the current brightness level. - fn brightness_get(&self, dev: &Self::Bus, classdev: &Device) -> = u32 { + fn brightness_get( + &self, + dev: &Self::Bus, + classdev: &::Device, + ) -> u32 { let _ =3D (dev, classdev); build_error!(VTABLE_DEFAULT_ERROR) } @@ -242,7 +252,7 @@ fn brightness_get(&self, dev: &Self::Bus, classdev: &De= vice) -> u32 { fn blink_set( &self, dev: &Self::Bus, - classdev: &Device, + classdev: &::Device, delay_on: &mut usize, delay_off: &mut usize, ) -> Result<()> { @@ -305,6 +315,16 @@ fn try_from(value: u32) -> core::result::Result { } } =20 +/// The led mode. +/// +/// Each led mode has its own led class device type with different capabil= ities. +/// +/// See [`Normal`]. +pub trait Mode: private::Sealed { + /// The class device for the led mode. + type Device>; +} + mod private { pub trait Sealed {} } diff --git a/rust/kernel/led/normal.rs b/rust/kernel/led/normal.rs index bd239f186c64..dda247145f25 100644 --- a/rust/kernel/led/normal.rs +++ b/rust/kernel/led/normal.rs @@ -6,11 +6,19 @@ =20 use super::*; =20 +/// The led mode for the `struct led_classdev`. Leds with this mode can on= ly have a fixed color. +pub enum Normal {} + +impl Mode for Normal { + type Device> =3D Device; +} +impl private::Sealed for Normal {} + /// The led class device representation. /// /// This structure represents the Rust abstraction for a led class device. #[pin_data(PinnedDrop)] -pub struct Device { +pub struct Device> { #[pin] ops: T, #[pin] @@ -19,7 +27,7 @@ pub struct Device { =20 impl<'a, S: DeviceBuilderState> DeviceBuilder<'a, S> { /// Registers a new [`Device`]. - pub fn build( + pub fn build>( self, parent: &'a T::Bus, ops: impl PinInit + 'a, @@ -89,7 +97,7 @@ pub fn build( } } =20 -impl Device { +impl> Device { /// # Safety /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a /// `led::Device`. @@ -107,17 +115,17 @@ fn parent(&self) -> &device::Device { } =20 // SAFETY: A `led::Device` can be unregistered from any thread. -unsafe impl Send for Device {} +unsafe impl + Send> Send for Device {} =20 // SAFETY: `led::Device` can be shared among threads because all methods o= f `led::Device` // are thread safe. -unsafe impl Sync for Device {} +unsafe impl + Sync> Sync for Device {} =20 -struct Adapter { +struct Adapter> { _p: PhantomData, } =20 -impl Adapter { +impl> Adapter { /// # Safety /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a /// `led::Device`. @@ -203,7 +211,7 @@ impl Adapter { } =20 #[pinned_drop] -impl PinnedDrop for Device { +impl> PinnedDrop for Device { fn drop(self: Pin<&mut Self>) { let raw =3D self.classdev.get(); 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bh=joSMi7pDlFO/HtroYqlGztfxeKGo9pyV8e9cWGgHrlI=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=VxCRHg7h4At7/qLaBdQ08SaFeU+NY0+7V/5AFnSsc8PJMxN2JNADv9BGrBTxqsf9p 6RII0mCb9rHhTYEPQ4WmY0e5/+6pTs8A7gIK5evlucMOaY5S6m6MZQWfKr3TXkowoe fyTqKqefwZzo+qaiEMNpPlMHwyroPp9d7n9bFHr9ltLSk0FlXkZA7tEDgOo7N0goQE Zdd6jyF6oTqbjLFUwAewjzygnHBTGjzFhW8ppmjM/7zdlNewQ+i/rXhLewtlUvOgIB 8kYgeBRfmzGRMu6HzF9M98i1i4wTkIHq19X3dLYC0Leh6kQwgROZ2/0zgEp6vc/jTx VkVouJk+jG7Eg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4fkLmW17Nyz9rxB; Sun, 29 Mar 2026 19:22:35 +0200 (CEST) From: Markus Probst Date: Sun, 29 Mar 2026 17:22:36 +0000 Subject: [PATCH v13 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: quoted-printable Message-Id: <20260329-rust_leds-v13-3-21a599c5b2d1@posteo.de> References: <20260329-rust_leds-v13-0-21a599c5b2d1@posteo.de> In-Reply-To: <20260329-rust_leds-v13-0-21a599c5b2d1@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=20776; i=markus.probst@posteo.de; h=from:subject:message-id; bh=Vd4ztAIIe3dZLs6GaRmT/tNaiOnzNJCI9BZUDIR6Eu4=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBpyV/TbqzDU7TwT7Kny9Lg4V01vlCuoOpnL8gV5 M5NEVd/J+iJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCaclf0xsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMSwyLDIACgkQNHYf+OetQ9Ko1w//ayEXm+UHfjX29jskh7k90p/11PUHdpA tRemzRphpfmOIo4YUR9wSkV6mi9EHck4qAv8Ee8RFfaUAsiOCWDGqOWsJsDx/NFWmLC1DciXn8s N2v1EhRGO0WT7nI76i673K31Y2rGLKp90yHL+DZI/XPcJbF2uvOVxwMKJZAhgsUYTObBFK/vQqY pmA6Q4gMOOVSnEllmCuHZT7Clq81MAcmua4XSDY5Oh9OxRPkly4yX2t5Fj7qJxLBob29nX5pv4g hKkNggjaBkRzBDkW57t8Evo1rEGKbtgplbj6fQB4VK5OVj/I47MUaGW+9Heaqijg82jkcITsFFw /3IHw+4GkN3tVcEf0eTkjvwXCtF0Rg8C0PgUAu2mPHbQ/dFd4m7alU4Un2/ybYeaKZk6JUrp4rG kTUpxpV5Mg11K8n2SvX4ZuGsz63ToTEOq22X6D22F6NLDcymbOLkr91IXHdG8zVSWWJMS46NKW/ N9W+Rw5m6GPUBxZFlt6BpI0pxbBqtCG2KTrcUATtRAPG2fv9nVSLb0k1YVqoRsd8hTvxj+SP/DW 3NNUh5Nhqb2b+kdVUGit/3lg0kql0UGDhdGlGTYJQ3HyVTKOnhRNT0O8w00VILXuFbctxiCgzQc D4dt0QIgRzpWR02+47spNaeSzRTNE4+5tOQA1e3apl0llLrk0JHE= 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 | 30 +++- rust/kernel/led/multicolor.rs | 387 ++++++++++++++++++++++++++++++++++++= ++++ 3 files changed, 417 insertions(+), 1 deletion(-) diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helpe= r.h index 083cc44aa952..3171e3e6351c 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -63,6 +63,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs index 5035563d68a3..a862d88cab29 100644 --- a/rust/kernel/led.rs +++ b/rust/kernel/led.rs @@ -33,8 +33,12 @@ }, // }; =20 +#[cfg(CONFIG_LEDS_CLASS_MULTICOLOR)] +mod multicolor; mod normal; =20 +#[cfg(CONFIG_LEDS_CLASS_MULTICOLOR)] +pub use multicolor::{MultiColor, MultiColorDevice, MultiColorSubLed}; pub use normal::{Device, Normal}; =20 /// The name of the led is determined by the driver. @@ -279,7 +283,24 @@ pub enum Color { Violet =3D bindings::LED_COLOR_ID_VIOLET, Yellow =3D bindings::LED_COLOR_ID_YELLOW, Ir =3D bindings::LED_COLOR_ID_IR, + #[cfg_attr( + CONFIG_LEDS_CLASS_MULTICOLOR, + doc =3D "Use this color for a [`MultiColor`] led." + )] + #[cfg_attr( + not(CONFIG_LEDS_CLASS_MULTICOLOR), + doc =3D "Use this color for a `MultiColor` led." + )] + /// If the led supports RGB, use [`Color::Rgb`] instead. Multi =3D bindings::LED_COLOR_ID_MULTI, + #[cfg_attr( + CONFIG_LEDS_CLASS_MULTICOLOR, + doc =3D "Use this color for a [`MultiColor`] led with rgb support." + )] + #[cfg_attr( + not(CONFIG_LEDS_CLASS_MULTICOLOR), + doc =3D "Use this color for a `MultiColor` led with rgb support." + )] Rgb =3D bindings::LED_COLOR_ID_RGB, Purple =3D bindings::LED_COLOR_ID_PURPLE, Orange =3D bindings::LED_COLOR_ID_ORANGE, @@ -319,7 +340,14 @@ fn try_from(value: u32) -> core::result::Result { /// /// Each led mode has its own led class device type with different capabil= ities. /// -/// See [`Normal`]. +#[cfg_attr( + CONFIG_LEDS_CLASS_MULTICOLOR, + doc =3D "See [`Normal`] and [`MultiColor`]." +)] +#[cfg_attr( + not(CONFIG_LEDS_CLASS_MULTICOLOR), + doc =3D "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..726fdaf068cb --- /dev/null +++ b/rust/kernel/led/multicolor.rs @@ -0,0 +1,387 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Led mode for the `struct led_classdev_mc`. +//! +//! C header: [`include/linux/led-class-multicolor.h`](srctree/include/lin= ux/led-class-multicolor.h) + +use crate::alloc::KVec; + +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> =3D MultiColorDevice; +} +impl private::Sealed for MultiColor {} + +/// The multicolor sub led info representation. +/// +/// This structure represents the Rust abstraction for a C `struct mc_subl= ed`. +#[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_classde= v_mc` to the driver via +// `Device::subleds()`. +// We need safeguards to ensure `MultiColorSubLed` and `mc_subled` stay id= entical. +const _: () =3D { + use core::mem::offset_of; + + const fn assert_same_type(_: &T, _: &T) {} + + let rust_zeroed =3D MultiColorSubLed { + color: Color::White, + brightness: 0, + intensity: 0, + channel: 0, + }; + let c_zeroed =3D bindings::mc_subled { + color_index: 0, + brightness: 0, + intensity: 0, + channel: 0, + }; + + assert!(offset_of!(MultiColorSubLed, color) =3D=3D offset_of!(bindings= ::mc_subled, color_index)); + assert_same_type(&0u32, &c_zeroed.color_index); + + assert!( + offset_of!(MultiColorSubLed, brightness) =3D=3D offset_of!(binding= s::mc_subled, brightness) + ); + assert_same_type(&rust_zeroed.brightness, &c_zeroed.brightness); + + assert!(offset_of!(MultiColorSubLed, intensity) =3D=3D offset_of!(bind= ings::mc_subled, intensity)); + assert_same_type(&rust_zeroed.intensity, &c_zeroed.intensity); + + assert!(offset_of!(MultiColorSubLed, channel) =3D=3D offset_of!(bindin= gs::mc_subled, channel)); + assert_same_type(&rust_zeroed.channel, &c_zeroed.channel); + + assert!(size_of::() =3D=3D 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, + } + } + + /// Set arbitrary data for the driver. + pub const fn channel(mut self, channel: u32) -> Self { + self.channel =3D channel; + self + } + + /// Set the initial intensity of the subled. + pub const fn initial_intensity(mut self, intensity: u32) -> Self { + self.intensity =3D intensity; + self + } +} + +/// The multicolor led class device representation. +/// +/// This structure represents the Rust abstraction for a multicolor led cl= ass 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 { + 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 =3D 0; + if subleds.iter().any(|subled| { + let bit =3D 1 << (subled.color as u32); + if (used & bit) !=3D 0 { + true + } else { + used |=3D bit; + false + } + }) { + dev_err!(parent.as_ref(), "duplicate color in mult= icolor led\n"); + return Err(EINVAL); + } + let mut subleds_vec =3D KVec::new(); + subleds_vec.extend_from_slice(subleds, GFP_KERNEL)?; + let (subled_info, num_colors, capacity) =3D subleds_ve= c.into_raw_parts(); + debug_assert_eq!(num_colors, capacity); + + // SAFETY: `try_ffi_init` guarantees that `ptr` is val= id for write. + // `led_classdev_mc` gets fully initialized in-place by + // `led_classdev_multicolor_register_ext` including `m= utex` and `list_head`. + unsafe { + ptr.write(bindings::led_classdev_mc { + led_cdev: bindings::led_classdev { + brightness_set: (!T::BLOCKING) + .then_some(Adapter::::brightness_se= t_callback), + brightness_set_blocking: T::BLOCKING + .then_some(Adapter::::brightness_se= t_blocking_callback), + brightness_get: T::HAS_BRIGHTNESS_GET + .then_some(Adapter::::brightness_ge= t_callback), + blink_set: T::HAS_BLINK_SET + .then_some(Adapter::::blink_set_cal= lback), + max_brightness: T::MAX_BRIGHTNESS, + brightness: self.initial_brightness, + default_trigger: self + .default_trigger + .map_or(core::ptr::null(), CStrExt::as= _char_ptr), + 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 ens= ure that + // `MultiColorSubLed` has an identical layout = to `mc_subled`. + subled_info: subled_info.cast::(), + }) + }; + + let mut init_data =3D 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_pt= r), + 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 initial= ized `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() + }, + ) + }) + .inspect_err(|_err| { + // SAFETY: `subled_info` is guaranteed to be a val= id array pointer to + // `mc_subled` with the length and capacity of `nu= m_colors`. + drop(unsafe { KVec::from_raw_parts(subled_info, nu= m_colors, num_colors) }); + })?; + + 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 wi= thin a + /// `led::MultiColorDevice`. + unsafe fn from_raw<'a>(led_cdev: *mut bindings::led_classdev) -> &'a S= elf { + // SAFETY: The function's contract guarantees that `led_cdev` poin= ts to a `led_classdev` + // field embedded within a valid `led::MultiColorDevice`. `contain= er_of!` can therefore + // safely calculate the address of the containing struct. + let led_mc_cdev =3D unsafe { container_of!(led_cdev, bindings::led= _classdev_mc, led_cdev) }; + + // SAFETY: It is guaranteed that `led_mc_cdev` points to a `led_cl= assdev_mc` + // field embedded within a valid `led::MultiColorDevice`. `contain= er_of!` can therefore + // safely calculate the address of the containing struct. + unsafe { &*container_of!(Opaque::cast_from(led_mc_cdev), Self, cla= ssdev) } + } + + fn parent(&self) -> &device::Device { + // SAFETY: `self.classdev.get()` is guaranteed to be a valid point= er to `led_classdev_mc`. + unsafe { device::Device::from_raw((*(*self.classdev.get()).led_cde= v.dev).parent) } + } + + /// 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 =3D 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 `MultiColor= SubLed` has an identical + // layout to `mc_subled`. + unsafe { + core::slice::from_raw_parts( + raw.subled_info.cast::(), + raw.num_colors as usize, + ) + } + } +} + +// SAFETY: A `led::MultiColorDevice` can be unregistered from any thread. +unsafe impl + Send> Send for MultiColorDevi= ce {} + +// SAFETY: `led::MultiColorDevice` can be shared among threads because all= methods of `led::Device` +// are thread safe. +unsafe impl + Sync> Sync for MultiColorDevi= ce {} + +struct Adapter> { + _p: PhantomData, +} + +impl> Adapter { + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin 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 =3D unsafe { MultiColorDevice::::from_raw(led_cdev= ) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T= ::Bus`. + let parent =3D 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 _ =3D classdev.ops.brightness_set(parent, classdev, brightness= ); + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::MultiColorDevice`. + /// This function is called on setting the brightness of a led immedia= tely. + 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 =3D unsafe { MultiColorDevice::::from_raw(led_= cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained i= n `T::Bus`. + let parent =3D unsafe { T::Bus::from_device(classdev.parent())= }; + + // SAFETY: `classdev.classdev.get()` is guaranteed to be a poi= nter to a valid + // `led_classdev_mc`. + unsafe { bindings::led_mc_calc_color_components(classdev.class= dev.get(), brightness) }; + + classdev.ops.brightness_set(parent, classdev, brightness)?; + Ok(0) + }) + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin 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 =3D unsafe { MultiColorDevice::::from_raw(led_cdev= ) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained in `T= ::Bus`. + let parent =3D unsafe { T::Bus::from_device(classdev.parent()) }; + + classdev.ops.brightness_get(parent, classdev) + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::MultiColorDevice`. + /// `delay_on` and `delay_off` must be valid pointers to `usize` and h= ave + /// 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 =3D unsafe { MultiColorDevice::::from_raw(led_= cdev) }; + // SAFETY: `classdev.parent()` is guaranteed to be contained i= n `T::Bus`. + let parent =3D 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 =3D 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 =3D unsafe { device::Device::from_raw((*r= aw).led_cdev.dev) }; + + let _fwnode =3D 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_class= dev_mc`. + let led_cdev =3D 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::Multico= lorDevice::new`. + drop(unsafe { + KVec::from_raw_parts( + led_cdev.subled_info, + led_cdev.num_colors as usize, + led_cdev.num_colors as usize, + ) + }); + } +} --=20 2.52.0