From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from LO2P265CU024.outbound.protection.outlook.com (mail-uksouthazon11021140.outbound.protection.outlook.com [52.101.95.140]) (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 CFD3E2D47FF; Fri, 4 Sep 2026 13:03:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.95.140 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788526991; cv=fail; b=T2SGyxCyEP4Awm19q1iiJglxp6Ol1Oyfrgp30hph4UdQTm68UOV0257swxNqhn5ZVZX+AVieh56GrXaebTvhnQzpNq1w/6RSfk3JC6TBJrcKXd1ZMaCbGPGEW5TC14ikl/tvGBWNYn3Eq5CdzYcMqAxcgDAS8JKljKHH4pGDvaE= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788526991; c=relaxed/simple; bh=m7szfGkZMPVCeB9+LxyBhhw60+H2PawbDiHVcC5fP1E=; h=Content-Type:Date:Message-Id:Cc:Subject:From:To:References: In-Reply-To:MIME-Version; b=EwPE29RlaKtl6k0PX67m8NGszP1RPABsiwpOUdJuGsnwPCi3vDjUu6i8USHzMOOnyW1x99JyacBG7TEhi1BSZVwK9+Vls0DDaHGKa9oc0ISv6/qx+gbK987vGIfL7zHGWJiPoLtH9mmtVK2F5rFbwQUoMVNf9kbAZdvGCEnhUpk= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=garyguo.net; spf=pass smtp.mailfrom=garyguo.net; dkim=pass (1024-bit key) header.d=garyguo.net header.i=@garyguo.net header.b=EMyLYFYb; arc=fail smtp.client-ip=52.101.95.140 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=garyguo.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=garyguo.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=garyguo.net header.i=@garyguo.net header.b="EMyLYFYb" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=l3Jp2glvt99LLHDWgHRYB4JRS3izlPbNIbQxRKEGW/CeqGXgmkQD7hfYqeGghQ99W1Czca6OxmlegPfXE3mD0aESArUnAWrHSHzAkiafCobfHsmGtucITT1FifZBs5t51GjWNbK2m5uQRjI67cGul+FIo8ZJls8zsj4LLfwcMRbudQTf5ko0VVqkqMe2zwD35hwXvncSrJgvxgu7vN01LoEci6FtWe3YoywPzO1cteBLcHNKOMu3qSHZ1GkNMcNWHb0pluE9yRv106xTb0LjxxT9LUzxmgCQY1ZPXSPSSrXVd3hdk4dxcz2YrDLnroV/JH0LkLLFFN9vvr0k2vDIsQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=Q93GhrDNpJue+te+T86YsYK8q50hQRYy/UJhTykFejU=; b=l8rDceM63cyYFrhk/l+qhPb2W0OG+bmkBohIxBrXQ2mNToZjIaxmRvR4v6kfq6b9MjgwogmLxlFz9/MwzQCh7KiRuRT1sZb2D7JqivSVgomCr2KTivuD95XOfLboxjoO3YtnLk3PN65lh9Hr+70ROA8mY4PpA6WHqemf61emeAJAKN/3za4Iec8o7l6TtaMNzlNs27oJ86X7j0HfGhzq6bMxxoLVOkdtXXVJ+qyZr38orY2x7e5vE8ZKvU/Hx23hgu4i1IdJ24B12GxDGnMSv8ZnhtRMlQvd8QUc52SYozCDMP7FKw0+bDhHH0fR8oZeSn3WVgDwBx7dFcqsL1223w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=garyguo.net; dmarc=pass action=none header.from=garyguo.net; dkim=pass header.d=garyguo.net; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=garyguo.net; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Q93GhrDNpJue+te+T86YsYK8q50hQRYy/UJhTykFejU=; b=EMyLYFYbpuSumsuvUwA9VJ4NEsnKh+JgLv/zmuuh5kc5zpiqES18Rl2qshAH4lYT/ARdZQ7lAraPfJLoOL/xyvLFBrjO75Cx9BwZGnlqu8P/YyFWQHIfJu2FZAQQsYG7YI/4ZST92LRxHlD+b9FIHpAOUz+tJK3/JV5clChZKRQ= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=garyguo.net; Received: from LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:4ab::19) by CWLP265MB6449.GBRP265.PROD.OUTLOOK.COM (2603:10a6:400:1e3::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.360.13; Fri, 4 Sep 2026 13:03:05 +0000 Received: from LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM ([fe80::f60b:1537:68d7:4fc1]) by LOAP265MB8560.GBRP265.PROD.OUTLOOK.COM ([fe80::f60b:1537:68d7:4fc1%4]) with mapi id 15.21.0360.008; Fri, 4 Sep 2026 13:03:05 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Fri, 04 Sep 2026 14:03:04 +0100 Message-Id: Cc: , , , Subject: Re: [PATCH v24 1/4] rust: leds: add basic led classdev abstractions From: "Gary Guo" To: "Markus Probst" , "Lee Jones" , "Pavel Machek" , "Greg Kroah-Hartman" , "Dave Ertman" , "Leon Romanovsky" , "Miguel Ojeda" , "Alex Gaynor" , "Gary Guo" , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , "Benno Lossin" , "Andreas Hindborg" , "Alice Ryhl" , "Trevor Gross" , "Danilo Krummrich" , "Rafael J. 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> +/// > +/// 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<'bound>( > +/// &self, > +/// _dev: &'bound platform::Device, > +/// _classdev: &led::Device<'bound, Self>, > +/// _brightness: u32 > +/// ) -> Result<()> { > +/// // Set the brightness for the led here > +/// Ok(()) > +/// } > +/// } > +/// ``` > +/// Led drivers must implement this trait in order to register and handl= e a [`Device`]. > +#[vtable] > +pub trait LedOps: Send + Sync + Sized { > + /// The bus device required by the implementation. > + #[allow(private_bounds)] > + type Bus: AsBusDevice; Does LED class device has no private data that driver can use? This can be either a private pointer or extra allocation living at the end of the class= dev struct. It's usually a antipattern to get the bus device directly, especially that = in Rust we do not allow anything other than callbacks to access data on bus devices. Instead, the class device registration should provide a data initializer, a= nd the callbacks would receive a pointer to the data instead. In cases that a device resource has to be referenced, it should be kept inside the private = data by the driver themselves. Best, Gary > + > + /// 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<'bound>( > + &self, > + dev: &'bound Self::Bus, > + classdev: &Device<'bound, Self>, > + brightness: u32, > + ) -> Result<()>; > + > + /// Gets the current brightness level. > + fn brightness_get<'bound>( > + &self, > + dev: &'bound Self::Bus, > + classdev: &Device<'bound, Self>, > + ) -> 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= should 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 = hardware accelerated > + /// blinking. > + /// > + /// See also [`LedOps::BLOCKING`]. > + fn blink_set<'bound>( > + &self, > + dev: &'bound Self::Bus, > + classdev: &Device<'bound, Self>, > + delay_on: &mut usize, > + delay_off: &mut usize, > + ) -> Result<()> { > + let _ =3D (dev, classdev, delay_on, delay_off); > + build_error!(VTABLE_DEFAULT_ERROR) > + } > +}