From nobody Sun Feb 8 22:06:18 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 6D4A03A9DAC for ; Thu, 22 Jan 2026 12:42:19 +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=1769085744; cv=none; b=ZZYxrdY5M5o4ZsVPRt7sEu8h6nSggzNRI0UehEZ33rU/8BKkoaPpy7cWEn2SJWZ81qmjpOgEL41PtrZrQ01HBX88TD5+TJagdfDsV8+4VoM+WNK+sw4vz0Jnqe5DX0LCpiJEZ/HKj0f+vZ6Tv9ubI6jLkK7Sy3Cezai/nj2IzaE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769085744; c=relaxed/simple; bh=N6WHSy8c0NzAU8oB7KrknhvTeFTR4kqg+Ncx19sjo70=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=FPWSN8fhn93KSY+sGMWJx88Li3s+aE1ThgRxnTcdGkHaNYN1EIR0lwCasApT3O5n2nDlJqhgOTFgaYf37KQzwBm1gBiO3jQ7UZgVoASs3W94z7iVpmfgz6HAPtzN29cszbbNQLdClDPe8n2RqKW4pPAJsp8UUIdAcXrHrIX+0kI= 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=F2+5zCna; 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="F2+5zCna" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 92824240109 for ; Thu, 22 Jan 2026 13:42:11 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1769085731; bh=esTUDMSBVGwKPdZCT2L0B5QkWdlvmml7AYloNpZ8G1g=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=F2+5zCna+C1aNXPc8o4fNDpbIEju47N6OwrVBPmFrVOgrI531RVrfhHCXcrQ0tzUy jdD8FNTBcio6iYDzcITsX/TLNd7uWn+RGfEaI/QIpfz1Yq+zmfLCMG3wJuq34ov/8v nhA4/5t35HMLn4Ih1ayC6Z9WVT0jBnj4j5d4cSFQhO1DnC6hRidEmPiIBNTu3Bcf/4 JLhJrjpVk5fQu4W31atHrQWMPY4U2RSSuhRtCvh6lWrpcQsKsvKB/rdo5ehQMRvMGs 8zyBcvxtiif+TJF9N9uiQWzVKrZXl5+wslUshsdgbAGVfoI1PuAWPEMA0SmHd5OlWs geqY5IS80iEFg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4dxggN1Xjgz6tw3; Thu, 22 Jan 2026 13:42:08 +0100 (CET) From: Markus Probst Date: Thu, 22 Jan 2026 12:42:10 +0000 Subject: [PATCH RESEND v10 2/3] rust: leds: split generic and normal led classdev abstractions up 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: <20260122-rust_leds-v10-2-fb9edb04b080@posteo.de> References: <20260122-rust_leds-v10-0-fb9edb04b080@posteo.de> In-Reply-To: <20260122-rust_leds-v10-0-fb9edb04b080@posteo.de> To: Lee Jones , Pavel Machek , Greg Kroah-Hartman , Dave Ertman , Ira Weiny , Leon Romanovsky , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , "Rafael J. Wysocki" , Bjorn Helgaas , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= Cc: rust-for-linux@vger.kernel.org, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Markus Probst X-Developer-Signature: v=1; a=openpgp-sha256; l=23506; i=markus.probst@posteo.de; h=from:subject:message-id; bh=N6WHSy8c0NzAU8oB7KrknhvTeFTR4kqg+Ncx19sjo70=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBpchsWDMvpYxZh+O279GbDSmPdMnuOVKPPnjhWk JalJrs3zbaJAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCaXIbFhsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMSwyLDIACgkQNHYf+OetQ9LeThAAivT6rWzoZ24lbF0ofw8G57Lylj0pwss +iqe9W9fLZ9HmZsXEZpLvOQjSpVdUOikd/yeS3AW7CrmBjc6t3aoVzVwbxJOxWgjtOZ8E90yqAb fMxkiZNsDLMaOEgkjXtiNMwlgmeM+S91xstPJglS0FRXgjjP4vgACHISNXGckgoP+ub4Y0wqLV7 WPpmrShhtzv3IcID1+h2VEVThttlL0yAnePhlW4hlIfqxJtpDt7AdD44KirUW1upLVbDgTSu7hW jbIbnZhtf8sj1Z11483d9WWHIFgJ4mrR83VOpun+3jKf2Symf5ebONUBYHYTUoJ73IsCCwV2KyV K9H3DUV34YfVvehCUK5agkkl1XTVedvgYUX27G/foO4J20AMJqdo1jeKeiNquKeTN7M36ifbTGE B+7ESNAn8MfBcS1otcDhboZyJlOm1pjy80XrZTS1JTJ1KONq6cMwcr0famInNiw7dRigsJuN65g 9ph7JsabW30MdodiTqgcAkWJQZQpnzOV41rKEI0iE2tyabhmt5/HRAgX3OMyBRo5u+QpwabA0AM 9BEwHXrWEzye2T7aFEpUCwcBl9hdpvrLK0yvaueGjmDPzxJAbiYx+bm1vxVZ6gwpxHZExWi15t3 1Dh/LTXwGfVkXQftexjIOmp+dp/+tuZzS74b6qa5UXCL67LdPwZ8= 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 Move code specific to normal led class devices into a separate file and introduce the `led::Mode` trait to allow for other types of led class devices in `led::LedOps`. Signed-off-by: Markus Probst --- MAINTAINERS | 1 + rust/kernel/led.rs | 242 ++++++------------------------------------= ---- rust/kernel/led/normal.rs | 223 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 256 insertions(+), 210 deletions(-) diff --git a/MAINTAINERS b/MAINTAINERS index 8c8648a26f93..d17c8f577ff3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14275,6 +14275,7 @@ L: linux-leds@vger.kernel.org L: rust-for-linux@vger.kernel.org S: Maintained F: rust/kernel/led.rs +F: rust/kernel/led/ =20 LEGO MINDSTORMS EV3 R: David Lechner diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs index cdd9b0300b72..a9eb2e8e480c 100644 --- a/rust/kernel/led.rs +++ b/rust/kernel/led.rs @@ -33,15 +33,9 @@ }, // }; =20 -/// The led class device representation. -/// -/// This structure represents the Rust abstraction for a C `struct led_cla= ssdev`. -#[pin_data(PinnedDrop)] -pub struct Device { - ops: T, - #[pin] - classdev: Opaque, -} +mod normal; + +pub use normal::{Device, Normal}; =20 /// The led init data representation. /// @@ -134,6 +128,7 @@ pub fn color(self, color: Color) -> 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; /// @@ -164,6 +159,12 @@ pub trait LedOps: Send + 'static + Sized { /// The bus device required by the implementation. #[allow(private_bounds)] type Bus: AsBusDevice; + + /// 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; @@ -176,12 +177,17 @@ 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) } =20 @@ -195,11 +201,12 @@ fn brightness_get(&self, _dev: &Self::Bus, _classdev:= &Device) -> u32 { /// See also [`LedOps::BLOCKING`]. fn blink_set( &self, - _dev: &Self::Bus, - _classdev: &Device, - _delay_on: &mut usize, - _delay_off: &mut usize, + 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) } } @@ -250,201 +257,16 @@ fn try_from(value: u32) -> core::result::Result { } } =20 -// 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 {} - -impl Device { - /// Registers a new led classdev. - /// - /// The [`Device`] will be unregistered on drop. - pub fn new<'a>( - parent: &'a T::Bus, - init_data: InitData<'a>, - ops: T, - ) -> impl PinInit, Error> + 'a { - Devres::new( - parent.as_ref(), - try_pin_init!(Self { - 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: init_data.initial_brightness, - default_trigger: init_data.default_trigger - .map_or(core::ptr::null(), CStrExt::as_cha= r_ptr), - color: init_data.color as u32, - ..bindings::led_classdev::default() - }) - }; - - let mut init_data_raw =3D bindings::led_init_data { - fwnode: init_data.fwnode - .as_ref() - .map_or(core::ptr::null_mut(), |fwnode| fwnode= .as_raw()), - default_label: core::ptr::null(), - devicename: init_data - .devicename - .map_or(core::ptr::null(), CStrExt::as_char_pt= r), - devname_mandatory: init_data.devname_mandatory, - }; - - // SAFETY: - // - `parent.as_raw()` is guaranteed to be a pointer t= o a valid `device` - // or a null pointer. - // - `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, - &raw mut init_data_raw, - ) - })?; - - core::mem::forget(init_data.fwnode); // keep the refer= ence count incremented - - Ok::<_, Error>(()) - }), - }), - ) - } - - /// # 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 pointer to = `led_classdev`. - unsafe { device::Device::from_raw((*(*self.classdev.get()).dev).pa= rent) } - } -} - -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) - }) - } +/// 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>; } =20 -#[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 `struct 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(self.classdev.get()) }; - } +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..710ae438a088 --- /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 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> { + ops: T, + #[pin] + classdev: Opaque, +} + +impl> Device { + /// Registers a new led classdev. + /// + /// The [`Device`] will be unregistered on drop. + pub fn new<'a>( + parent: &'a T::Bus, + init_data: InitData<'a>, + ops: T, + ) -> impl PinInit, Error> + 'a { + Devres::new( + parent.as_ref(), + try_pin_init!(Self { + 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: init_data.initial_brightness, + default_trigger: init_data.default_trigger + .map_or(core::ptr::null(), CStrExt::as_cha= r_ptr), + color: init_data.color as u32, + ..bindings::led_classdev::default() + }) + }; + + let mut init_data_raw =3D bindings::led_init_data { + fwnode: init_data.fwnode + .as_ref() + .map_or(core::ptr::null_mut(), |fwnode| fwnode= .as_raw()), + default_label: core::ptr::null(), + devicename: init_data + .devicename + .map_or(core::ptr::null(), CStrExt::as_char_pt= r), + devname_mandatory: init_data.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, + &raw mut init_data_raw, + ) + })?; + + core::mem::forget(init_data.fwnode); // keep the refer= ence count incremented + + Ok::<_, Error>(()) + }), + }), + ) + } + + /// # 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> Send for Device {} + +// SAFETY: `led::Device` can be shared among threads because all methods o= f `led::Device` +// are thread safe. +unsafe impl + Sync> 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) }; + } +} --=20 2.52.0