From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-244108.protonmail.ch (mail-244108.protonmail.ch [109.224.244.108]) (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 CCBDE23E33D; Wed, 20 Aug 2025 04:24:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.224.244.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755663897; cv=none; b=CbekAq6cxyG8qPA33HRgLS929zt3sdnJwT0fWkiUKkWGEW2S5N6ygAsq+W/ncHZ1cfb4nyGW1YgN/PhZYGjqJA35nYhDtnT7DOMtV6tBlg4nv86I4708rF+Am7/mQmFAK9Gqd88QIY2ppqhx3i+gqMdgE9D2qfgf7kZV511FOq4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755663897; c=relaxed/simple; bh=86INfeqOfumVZ1BamH5eEpxeWtBAse6F5jxR+VSqTKo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MpWy93R4iyd6/3otHJa6qdkJ88RI5vB5OXfs6r+DOkeA0JYU5PkAZ+Q+E8jKyrEilzCr1RZm5S6GY1wUSqhfMVZFgCIpooqs66dCVQenEiJ723VCT20P3v/wX/0JSuwId89JpQlNEALUfKo6rnWOulhureSfo6CW+TKbKPMZ5+Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weathered-steel.dev; spf=pass smtp.mailfrom=weathered-steel.dev; dkim=pass (2048-bit key) header.d=weathered-steel.dev header.i=@weathered-steel.dev header.b=lY2GCTmk; arc=none smtp.client-ip=109.224.244.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weathered-steel.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weathered-steel.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=weathered-steel.dev header.i=@weathered-steel.dev header.b="lY2GCTmk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=weathered-steel.dev; s=protonmail3; t=1755663892; x=1755923092; bh=kKgqwZvsNzF2JctvkwujV6LyTG531m1YAQmuNypBdos=; h=Date:From:To:Cc:Subject:Message-ID:References:In-Reply-To:From:To: Cc:Date:Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=lY2GCTmknx+UB3Ztg5WpZwoXyn8WZChzrFFy428DfD1UwTql5KDlUxK/SG3I95ECI ajdzy/Fh79hGBmjcS9S4FtxBmHLk988OTaDlb9DKksK/PhdxOKTCZh0Uy/QEsqbGSn VZdhn+fM8WjngXkS2ba7Sfhg8zhveoVkX8Pxn01fv0ah+vc5zJNaWbW+QQOLx7O8LW MK85lAKqbiQX4yDtW3CCbsE1D7JAMRCBeGTn5zOGVkLwmOoP2vui81h2oh6kxAVMvm OoSrjDjCrhLUryB+zY2Cs/IsoILRE+AcmrHhSZcM6Aidq5HNlZdZGrFGkYXGb52FCA ocLgFA49dQWrA== X-Pm-Submission-Id: 4c6Cz659Tdz2ScCj Date: Wed, 20 Aug 2025 04:24:47 +0000 From: Elle Rhumsaa To: Daniel Almeida Cc: Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Alexandre Courbot , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, kernel@collabora.com, linux-media@vger.kernel.org Subject: Re: [PATCH 7/7] rust: samples: add the v4l2 sample driver Message-ID: References: <20250818-v4l2-v1-0-6887e772aac2@collabora.com> <20250818-v4l2-v1-7-6887e772aac2@collabora.com> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250818-v4l2-v1-7-6887e772aac2@collabora.com> On Mon, Aug 18, 2025 at 02:49:53AM -0300, Daniel Almeida wrote: > This driver is the only user of the v4l2 abstractions at the moment. It > serves as a means to validate the abstractions by proving that the > device is actually registered as /dev/videoX, and it can be opened and > queried by v4l2-ctl, while also serving as a display of the current v4l2 > support in Rust, as well as a blueprint for more elaborate Rust v4l2 > drivers in the future. > > Signed-off-by: Daniel Almeida > --- > MAINTAINERS | 1 + > samples/rust/Kconfig | 11 +++ > samples/rust/Makefile | 1 + > samples/rust/rust_driver_v4l2.rs | 145 +++++++++++++++++++++++++++++++++++++++ > 4 files changed, 158 insertions(+) > > diff --git a/MAINTAINERS b/MAINTAINERS > index 6fc5d57950e474d73d5d65271a0394efc5a8960b..14521bc0585503992da582f2cee361666985e39f 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -15440,6 +15440,7 @@ L: linux-media@vger.kernel.org > L: rust-for-linux@vger.kernel.org > S: Supported > F: rust/media > +F: sample/rust/rust_driver_v4l2.rs > > MEDIATEK BLUETOOTH DRIVER > M: Sean Wang > diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig > index 7f7371a004ee0a8f67dca99c836596709a70c4fa..64422acf1e9da9d05f904e14fd423b3b4aef173a 100644 > --- a/samples/rust/Kconfig > +++ b/samples/rust/Kconfig > @@ -105,6 +105,17 @@ config SAMPLE_RUST_DRIVER_AUXILIARY > > If unsure, say N. > > +config SAMPLE_RUST_DRIVER_V4L2 > + tristate "Video4Linux2 driver" > + depends on MEDIA_SUPPORT && VIDEO_DEV > + help > + This option builds the Rust V4L2 driver sample. > + > + To compile this as a module, choose M here: > + the module will be called rust_driver_v4l2. > + > + If unsure, say N. > + > config SAMPLE_RUST_HOSTPROGS > bool "Host programs" > help > diff --git a/samples/rust/Makefile b/samples/rust/Makefile > index bd2faad63b4f3befe7d1ed5139fe25c7a8b6d7f6..57e21f0373938bb70b4cb400ea550010895b4c94 100644 > --- a/samples/rust/Makefile > +++ b/samples/rust/Makefile > @@ -9,6 +9,7 @@ obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI) += rust_driver_pci.o > obj-$(CONFIG_SAMPLE_RUST_DRIVER_PLATFORM) += rust_driver_platform.o > obj-$(CONFIG_SAMPLE_RUST_DRIVER_FAUX) += rust_driver_faux.o > obj-$(CONFIG_SAMPLE_RUST_DRIVER_AUXILIARY) += rust_driver_auxiliary.o > +obj-$(CONFIG_SAMPLE_RUST_DRIVER_V4L2) += rust_driver_v4l2.o > obj-$(CONFIG_SAMPLE_RUST_CONFIGFS) += rust_configfs.o > > rust_print-y := rust_print_main.o rust_print_events.o > diff --git a/samples/rust/rust_driver_v4l2.rs b/samples/rust/rust_driver_v4l2.rs > new file mode 100644 > index 0000000000000000000000000000000000000000..a3ef98a613f2fed9e8589f0761ce7e43029c02b6 > --- /dev/null > +++ b/samples/rust/rust_driver_v4l2.rs > @@ -0,0 +1,145 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// SPDX-copyrightText: Copyright (C) 2025 Collabora Ltd. > + > +//! Rust V4L2 sample driver. > +//! > +//! This sample demonstrates how to: > +//! - Register a V4L2 device (struct v4l2_device), > +//! - Register a video node (struct video_device) using the Rust V4L2 > +//! abstractions, > +//! - Implement support for a V4L2 ioctl in a driver. > +//! > +//! It implements only `VIDIOC_QUERYCAP` and minimal open/close handling. > + > +use kernel::{ > + c_str, > + device::Core, > + media::v4l2::{ > + self, > + caps::{self, DeviceCaps}, > + video, > + }, > + of, platform, > + prelude::*, > + types::ARef, > + ThisModule, > +}; > + > +/// The private data associated with the V4L2 device. > +#[pin_data] > +struct Data {} > + > +/// The private data associated with a V4L2 device node, i.e. `struct > +/// video_device`. > +#[pin_data] > +struct VideoData {} > + > +/// The private data associated with a V4L2 file, i.e. `struct v4l2_fh`. > +#[pin_data] > +struct File {} > + > +impl v4l2::file::DriverFile for File { > + type Driver = SampleDriver; > + > + const MODULE: &'static ThisModule = &THIS_MODULE; > + > + fn open(_vdev: &v4l2::video::Device) -> impl PinInit { > + try_pin_init!(Self {}) > + } > +} > + > +struct SampleDriver { > + _pdev: ARef, > + _v4l2_reg: v4l2::device::Registration, > + video_reg: video::Registration, > +} > + > +impl v4l2::device::Driver for SampleDriver { > + type Data = Data; > +} > + > +#[vtable] > +impl video::Driver for SampleDriver { > + type Data = VideoData; > + type File = File; > + > + const NODE_TYPE: video::NodeType = video::NodeType::Video; > + const DIRECTION: video::Direction = video::Direction::Rx; > + const NAME: &'static CStr = c_str!("rv4l2"); > + const CAPS: DeviceCaps = caps::device_caps::VIDEO_CAPTURE; > + > + fn querycap( > + _file: &v4l2::file::File, > + _data: &::Data, > + cap: &mut caps::Capabilities, > + ) -> Result { > + cap.set_driver(c_str!("rv4l2"))?; > + cap.set_card(c_str!("rv4l2"))?; > + cap.set_bus_info(c_str!("platform:rv4l2"))?; > + > + cap.set_device_caps(Self::CAPS); > + Ok(()) > + } > +} > + > +kernel::of_device_table!( > + OF_TABLE, > + MODULE_OF_TABLE, > + ::IdInfo, > + [(of::DeviceId::new(c_str!("test, rust-v4l2")), ())] > +); > + > +impl platform::Driver for SampleDriver { > + type IdInfo = (); > + const OF_ID_TABLE: Option> = Some(&OF_TABLE); > + > + fn probe( > + pdev: &platform::Device, > + _info: Option<&Self::IdInfo>, > + ) -> Result>> { > + let dev = pdev.as_ref(); > + > + let v4l2_reg = > + v4l2::device::Registration::::new(dev, try_pin_init!(Data {}), GFP_KERNEL)?; > + > + let video_reg = video::Registration::::new( > + v4l2_reg.device(), > + try_pin_init!(VideoData {}), > + GFP_KERNEL, > + )?; > + > + let this = KBox::new( > + Self { > + _pdev: pdev.into(), > + _v4l2_reg: v4l2_reg, > + video_reg, > + }, > + GFP_KERNEL, > + )?; > + > + dev_info!( > + dev, > + "Registered /dev/video{}\n", > + this.video_reg.device().num() > + ); > + Ok(this.into()) > + } > + > + fn unbind(pdev: &platform::Device, _this: Pin<&Self>) { > + dev_info!(pdev.as_ref(), "Unbinding Rust V4L2 sample driver\n"); > + } > +} > + > +impl Drop for SampleDriver { > + fn drop(&mut self) { > + dev_dbg!(self._pdev.as_ref(), "Rust V4L2 sample driver removed\n"); > + } > +} > + > +kernel::module_platform_driver! { > + type: SampleDriver, > + name: "rust_driver_v4l2", > + authors: ["Daniel Almeida"], > + description: "Rust V4L2 sample video driver", > + license: "GPL v2", > +} > > -- > 2.50.1 Reviewed-by: Elle Rhumsaa