From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 4096925DD0B for ; Wed, 21 May 2025 11:52:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747828369; cv=none; b=VaeW1DcKcIA/ong1dMvvEi3bu6cHD9nVnrraZM7Ps01SbtkfCei8FU2p5QZtsK1qiQEmfYl3tDctoXCl1wG+YiNa7Ar04iW160LbXwIeEmrykc2w84R6jGrnxBZEoWsHiiQIViLmvXPcalS8bhL/yQJ56Sf/Phx0b8N5WJ1faOU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747828369; c=relaxed/simple; bh=1lIpQjeZWM4B9/XmD81iy/IEh/WiTrtNntrczpbhpoc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AJJbueNFqrW1b15qNEEFljMExeB+BTdj616i7xu4Gvc9E38gZs8Lu5J7t9iELvRFkmHNnwcBFMyKpJ+T4S24LdUzfHa4m0gpXXRzbDbXzV47rkY7g0Vj+/Pzi/5KGYfMEEfYekQZ7CR/wsnF2GVWRG/I9iiD/U530Q5VVrYmEE4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=hm4IfOYr; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="hm4IfOYr" Received: from pendragon.ideasonboard.com (179.218-130-109.adsl-dyn.isp.belgacom.be [109.130.218.179]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id BA70F6AF; Wed, 21 May 2025 13:52:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1747828343; bh=1lIpQjeZWM4B9/XmD81iy/IEh/WiTrtNntrczpbhpoc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hm4IfOYrhHp6JXpwuzKAnBrmQUO7WP7cZNSiyOc+Hg7tHFzZg007Q3hUcH/qEBJQq NbITT004qqSDRlaZtWqFId+aM//kCbBT6OkLm8MUKXH1BL3HB0NR5aavDJrwL4JF/l CzRzezaXpeAnAUStyKWW3yVhYil0hHAHNAvkQ/f8= Date: Wed, 21 May 2025 13:52:39 +0200 From: Laurent Pinchart To: Stefan Wahren Cc: Greg Kroah-Hartman , Florian Fainelli , Phil Elwell , Dan Carpenter , linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, kernel-list@raspberrypi.com, linux-staging@lists.linux.dev Subject: Re: [PATCH RFC 2/2] staging: vc04_services: Document VCHIQ character device Message-ID: <20250521115239.GI12514@pendragon.ideasonboard.com> References: <20250509221152.13564-1-wahrenst@gmx.net> <20250509221152.13564-3-wahrenst@gmx.net> <2025052121-glisten-serpent-8ede@gregkh> <20250521112815.GA25453@pendragon.ideasonboard.com> <4cac2c68-a975-4b68-92c4-91e90ffe8041@gmx.net> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <4cac2c68-a975-4b68-92c4-91e90ffe8041@gmx.net> On Wed, May 21, 2025 at 01:39:15PM +0200, Stefan Wahren wrote: > Am 21.05.25 um 13:28 schrieb Laurent Pinchart: > > On Wed, May 21, 2025 at 01:20:54PM +0200, Greg KH wrote: > >> On Sat, May 10, 2025 at 12:11:52AM +0200, Stefan Wahren wrote: > >>> From: Phil Elwell > >>> > >>> Document the IOCTLs for the VCHIQ character device, which provide > >>> a userspace interface to access the VideoCore VPU of the > >>> Raspberry Pi. Several ARM side libraries make use of it like EGL, > >>> MMAL and OpenMAX. > >>> > >>> Link: https://github.com/raspberrypi/linux/pull/6801 > >>> Signed-off-by: Phil Elwell > >>> [wahrenst@gmx.net: Rewrite commit log] > >>> Signed-off-by: Stefan Wahren > >>> --- > >>> .../vc04_services/Documentation/vchiq-cdev | 87 +++++++++++++++++++ > >>> 1 file changed, 87 insertions(+) > >>> create mode 100644 drivers/staging/vc04_services/Documentation/vchiq-cdev > >>> > >>> diff --git a/drivers/staging/vc04_services/Documentation/vchiq-cdev b/drivers/staging/vc04_services/Documentation/vchiq-cdev > >>> new file mode 100644 > >>> index 000000000000..99ab2567643e > >>> --- /dev/null > >>> +++ b/drivers/staging/vc04_services/Documentation/vchiq-cdev > >>> @@ -0,0 +1,87 @@ > >>> +What: /dev/vchiq > >>> +Date: October 2016 > >>> +KernelVersion: 4.9 > >>> +Contact: kernel-list@raspberrypi.com > >>> +Description: > >>> + The ioctl interface for the VCHIQ character device. > >>> + Following actions are supported: > >>> + > >>> + * VCHIQ_IOC_CONNECT: > >>> + Establish/confirm the link to the VPU peer. > >> > >> I understand the need, but this does not document the parameters to the > >> ioctls, so it's not all that useful. How about just a normal > >> documentation file with this all written out? > > > > That would be my preference too, somewhere in > > Documentation/userspace-api/. > > could you please point me to a comparable IOCTL documenation to better > understand your expectations? Documentation/userspace-api/gpio/ seems to be a good example. You can split ioctls in different files, see gpio-get-chipinfo-ioctl.rst for instance. If several ioctls are closely related they can also be documented in the same file, see for instance Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst. -- Regards, Laurent Pinchart