From nobody Sun Jun 14 07:36:21 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 25AA53C2787 for ; Fri, 1 May 2026 14:36:09 +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=1777646172; cv=none; b=Q4fDlc7Y7RL3NZN+1d1OfekvwqVMVl6N+WsnnEDsYwXsNnojLHltm5XlA72BjHJqXEv1VscpuznIEFzWy81q1goXCPuDZ1UNBjmj0EYi1beac/jSL+N2vcWLlj/ZssnlahimaFzWix/DLZb/xrZpF0qBrsQEqcWuO6lezaIDgHs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777646172; c=relaxed/simple; bh=pz/MQd+oIXEiSaxJiT/v4Yuocz8aeibOGSPRfNbErek=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=pzMQOq3WdK0ApVPmOYxGc0ajtlBRkgIwewpKOx1079Z8SKA5IV09Ui0Hcm8aGn4/36Rl21S7IuyqAQseItuxxyQVsqKx+jQ9YaAu6Ye0I7oy1X+GiRECN1PHc9PwY1L8mlW8j2NX7eo6BLZFLITsA2jpYFxYUB/yu3lbMbmO+uA= 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=KbM8iW+H; 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="KbM8iW+H" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 7798F240103 for ; Fri, 1 May 2026 16:36:05 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1777646165; bh=Ngals+PzGsxWLAwKjLijdCmWQTCcEjJ/j1wWGv5N5Zw=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=KbM8iW+HYXJbyqp7Hnc+rZbVsz4O7IJeyk+FsEmnwRwSDkdu17hsU9AUbYmdSYRF5 KY+OQv4ji6R4PNIEhflCnqRmRDI+60OX1vsRUMuYomO38XwQ1T82l0oDoPLpzut6AY D5XBuB2shLqJTb2AyyDEyjnOWinwqy4mZKldele/GH1cXnh6bVOWY5xzdkFeo/NcGg cJK69FbcN65hbsQWraM3gpwg35fwlULoXFHMotqtJrqxx6O4E63CoSmcHR5Wc1c49J Xmiq2cuFlBbgtxJlmWUHEkq+D2WhRivBlrG5hB67Zfx2ljiq7dNxwiN/pAlkZMYbTn B3Y1q3EQN8uMQ== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4g6YW71Xbqz9rxL; Fri, 1 May 2026 16:36:03 +0200 (CEST) From: Markus Probst Date: Fri, 01 May 2026 14:36:04 +0000 Subject: [PATCH v16 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: <20260501-rust_leds-v16-1-9f329fdedcd9@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=20621; i=markus.probst@posteo.de; h=from:subject:message-id; bh=pz/MQd+oIXEiSaxJiT/v4Yuocz8aeibOGSPRfNbErek=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBp9LpQWshcu09Kz3GjtT7A9gqGkSEGKIhqTgdHK TWMFGpHIXmJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCafS6UBsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQNHYf+OetQ9Ksvw/8CnueCmgTGLoRHUOPFLpSHJ3azBgft+W B3a49L5AUZYkDTq0giyVDNyJ3F9AgbrjYLnr+5dxNJTSg/G0qN5i51Jv9xf6aGPEGezqPipx4R/ WcVJDxeUer061mSBVomKzE8bRoup7Iac/86uFwF07155JK2jIwDMriBB43U6BenLu99RCxKBkMD pkq4PktKXtqKX2Yfh7fS5HscUArlliMEd4URwbJ25Ua827d1rX32dtAhEQFmbz0pyDGA/kdH2N7 +we858Can7RYsUhBm7k5gkfz7/9TSbTBC0dLXnqs0QFhzZQep6xcSOOvsi/VVloI7bAOJyltbED KU561yv38xTxTgFNOwJ4B6jONWrBO32UvwRzbZ7MC29Ht+yfPB/ebQ7gVgRP1K3Lqh+387/kVbN 2xvGQJLXq3c50vb7+VNCfOGkwhyQUE8uJEEUOydcIgVHC+2pSOOgptu5s7O435KZdPROajOFmnh Y1X6UHG1ouRbpM/8fC1Av8pNPilzpaiQ/5jhKuTibJ+8XyIXLv/ds/EmQVcM/LVMKMWmaLSxm1M xrzqI5IYihu90tviue+zpUuc4j0Or/+GDJ9l8soFRQwO1xZ9vKP/lGbrzByFvCw/RkoZElKRejN lt6vJOYBK3ykzJw8lEgtwJKCEansNualabKYE2sHDbPVStT4qBPA= 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 | 296 ++++++++++++++++++++++++++++++++++++++++++= ++++ rust/kernel/led/normal.rs | 230 +++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + 4 files changed, 535 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 4367a303e90e..1cce5359c23e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14520,6 +14520,14 @@ 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..57746b0b08ca --- /dev/null +++ b/rust/kernel/led.rs @@ -0,0 +1,296 @@ +// 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, + sync::aref::ARef, + types::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, + 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, + 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 + } + } + + /// 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 + Sync + '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) -> = Result { + 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 + #[inline] + 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..6715ddf911be --- /dev/null +++ b/rust/kernel/led/normal.rs @@ -0,0 +1,230 @@ +// 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 { + const_assert!(T::MAX_BRIGHTNESS <=3D i32::MAX.unsigned_abs() || !T= ::HAS_BRIGHTNESS_GET); + + 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, + 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) } + } + + #[inline] + 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()) }; + + // CAST: Resulting value will be casted back to i32 in the led sub= system. + from_result(|| { + classdev + .ops + .brightness_get(parent, classdev) + .inspect(|val| debug_assert!(*val <=3D 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 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 b72b2fbe046d..7a18c738c934 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -89,6 +89,7 @@ pub mod jump_label; #[cfg(CONFIG_KUNIT)] pub mod kunit; +pub mod led; pub mod list; pub mod maple_tree; pub mod miscdevice; --=20 2.53.0 From nobody Sun Jun 14 07:36:21 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 25A193C1963 for ; Fri, 1 May 2026 14:36:09 +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=1777646171; cv=none; 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Fri, 1 May 2026 16:36:04 +0200 (CEST) From: Markus Probst Date: Fri, 01 May 2026 14:36:05 +0000 Subject: [PATCH v16 2/3] rust: leds: add Mode trait 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: <20260501-rust_leds-v16-2-9f329fdedcd9@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=5332; i=markus.probst@posteo.de; h=from:subject:message-id; bh=E3bzm3QfblHpymqQiQxNq+2D7OfbgIrNy1j3vjDCsY8=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBp9LpQPk288lLbmRXPjYIv3XlTbqajWBkB1Wi2I PMxfPGWaiCJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCafS6UBsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMiwyLDIACgkQNHYf+OetQ9Lr/RAAjLKd9iLV4ghqqKSRVJGKIIq2NDZmBlK W6JmmWzqQaDNOsr0RBCtofqc4emDZ/IYEyCgYG87YyI0AloIL2hNOT9sZTcIAJ4adMQvrRPDFLC 71iDEy6aCJtdVKiLjIthgaOXE4jfcF8sZ4q6j0o4IMpClEDWktpWO3PseBHyokZuLvAfaM/jXsP hy8qqUR0JGgvBNxe96jO8KYAE2jgoYQHdFoJio+0+acgZCzbnaOudg0+4bAnxjmpg/nxDA2gjM5 HLFyoCS4mmTu2VBHh+Uih4kwmmnDfIH69t3OxXPPifvb/P75EnvEMKV11tyUrXTeAJHqakSud6k U96fpcN+Yz2nK/wkKGt3rkCg3MFGjjt78JwjmZ58B1VNqWtneqkiXA6UF/7K1s2qS/X/pKqL0ay wdBr9Y+qjFKL5FG7VVW6rVH4SvjhJuUgWqRRN4eWPfi1vMOy+egSmLM4HfR3Jka5MgwFPFQ6TCm 4QRb0/ynV/ufCYXPTC42VWAhGAeHE2d/y2Z3HgIyMKf6RJB548Meb1UoE7MUrrtku6cvaLQUz5t JNHCxBKCRpVxtzGL4/YIb98qoZbzm/yyEwZGZOKOCscAfAabP6k5GNOgYBnSULGv6t1JMsojAKP nPS6wCINjDvyZcqKAstBI4FW8/nATRBbnDRqd0GajjpR+FBhvljQ= 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 Add the `led::Mode` trait to allow for other types of led class devices in `led::LedOps`. Signed-off-by: Markus Probst --- rust/kernel/led.rs | 31 +++++++++++++++++++++++++++---- rust/kernel/led/normal.rs | 24 ++++++++++++++++-------- 2 files changed, 43 insertions(+), 12 deletions(-) diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs index 57746b0b08ca..5ddfee47f911 100644 --- a/rust/kernel/led.rs +++ b/rust/kernel/led.rs @@ -33,7 +33,10 @@ =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 {} @@ -162,6 +165,7 @@ 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; /// @@ -194,6 +198,11 @@ pub trait LedOps: Send + Sync + '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; @@ -206,12 +215,16 @@ pub trait LedOps: Send + Sync + '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) -> = Result { + fn brightness_get( + &self, + dev: &Self::Bus, + classdev: &::Device, + ) -> Result { let _ =3D (dev, classdev); build_error!(VTABLE_DEFAULT_ERROR) } @@ -227,7 +240,7 @@ fn brightness_get(&self, dev: &Self::Bus, classdev: &De= vice) -> Result, + classdev: &::Device, delay_on: &mut usize, delay_off: &mut usize, ) -> Result<()> { @@ -291,6 +304,16 @@ 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 6715ddf911be..ad69ed85feb0 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, @@ -88,7 +96,7 @@ 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`. @@ -210,7 +218,7 @@ 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(); // SAFETY: The existence of `self` guarantees that `self.classdev.= get()` is a pointer to a --=20 2.53.0 From nobody Sun Jun 14 07:36:21 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 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; 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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: quoted-printable 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_helpe= r.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, // }; =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, // @@ -267,7 +275,24 @@ 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, @@ -308,7 +333,14 @@ 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..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/lin= ux/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> =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. + #[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 =3D channel; + self + } + + /// Set the initial intensity of the subled. + #[inline] + 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 { + const_assert!(T::MAX_BRIGHTNESS <=3D 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 =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); + + let subled_guard =3D ScopeGuard::new(|| { + // 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) }); + }); + + // 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, + 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() + }, + ) + })?; + + 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 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) } + } + + #[inline] + 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`]. + #[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 =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::(), + // 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 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()) }; + + // CAST: Resulting value will be casted back to i32 in the led sub= system. + from_result(|| { + classdev + .ops + .brightness_get(parent, classdev) + .inspect(|val| debug_assert!(*val <=3D 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 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 2.53.0