From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3D11C433E0 for ; Fri, 26 Jun 2020 01:12:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B14720767 for ; Fri, 26 Jun 2020 01:12:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="grSCHd6G" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726988AbgFZBM4 (ORCPT ); Thu, 25 Jun 2020 21:12:56 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:46868 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726252AbgFZBM4 (ORCPT ); Thu, 25 Jun 2020 21:12:56 -0400 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 13A1D595; Fri, 26 Jun 2020 03:12:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1593133973; bh=OGnn3Du3CGaosILghe0jhZN8MxKh5aDNKLaqOQFHkps=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=grSCHd6GQJkQiVjtsiow7VRDaWX/2mg+YJHmhO/Csv4kPpErwiM+AktRcwgZ3cd0g jXSdHvuy6gISYKdgEueXpt1KLlyWRJuroN3lkRP6oOKevlD4Y6ZtQRlvJNtKNzSebq e0ecGJsBTkMQqVxxKmFvlSyIZlCRAAtlJFu+QIDc= Date: Fri, 26 Jun 2020 04:12:51 +0300 From: Laurent Pinchart To: Steve Longerbeam Cc: Jacopo Mondi , Ramzi BEN MEFTAH , niklas soderlund , Kieran Bingham , Mauro Carvalho Chehab , Hans Verkuil , Sakari Ailus , Janusz Krzysztofik , Ezequiel Garcia , Arnd Bergmann , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Rodin , efriedrich@de.adit-jv.com, erosca@de.adit-jv.com Subject: Re: [PATCH 1/3] v4l2-subdev: Add subdev ioctl support for ENUM/GET/SET INPUT Message-ID: <20200626011251.GP5865@pendragon.ideasonboard.com> References: <1592301619-17631-1-git-send-email-rbmeftah@de.adit-jv.com> <20200624075307.hl6wew7vr5ue225t@uno.localdomain> <20200625020138.GW5980@pendragon.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Steve, On Thu, Jun 25, 2020 at 10:41:09AM -0700, Steve Longerbeam wrote: > On 6/24/20 7:01 PM, Laurent Pinchart wrote: > > On Wed, Jun 24, 2020 at 09:53:07AM +0200, Jacopo Mondi wrote: > >> On Tue, Jun 16, 2020 at 12:00:15PM +0200, Ramzi BEN MEFTAH wrote: > >>> From: Steve Longerbeam > >> +Niklas, +Laurent > >> > >> Niklas, Laurent, how does this play with CAP_IO_MC ? > > I don't think it's related to CAP_IO_MC, but I don't think it's a good > > idea either :-) Routing doesn't go through the subdev [gs]_input > > operations in MC-based drivers. It should be configured through link > > setup instead. This patch goes in the wrong direction, sorry Steve. > > That's OK! :) I didn't submit this patch, and as stated in the commit > header, I never recommended this patch be submitted to upstream in the > first place. > > Selecting inputs at a subdev should normally make use of media link > setup. But for selecting analog signal inputs, such as the ADV748x AFE > standard definition inputs, that would  mean there would need to exist > source "analog" subdevs that connect to the AFE inputs, if only for the > purpose of selecting those inputs, which seems silly IMHO. The ADV748x > AFE subdev defines these inputs as media pads, but have no connections, > so link setup API can't be used to select those inputs. > > So a new subdev pad API is clearly needed, not just to get input status > at a subdev pad, but to select/make active such analog inputs without > requiring link setup API. There was an attempt to create a subdev ioctl to configure internal routing. See "[PATCH v4 19/31] media: Documentation: Add GS_ROUTING documentation" ([1]) and the related patches in the series. [1] https://lore.kernel.org/linux-media/20190328200608.9463-20-jacopo+renesas@jmondi.org/ > >>> This commit enables VIDIOC_ENUMINPUT, VIDIOC_G_INPUT, and VIDIOC_S_INPUT > >>> ioctls for use via v4l2 subdevice node. > >>> > >>> This commit should probably not be pushed upstream, because the (old) > >>> idea of video inputs conflicts with the newer concept of establishing > >>> media links between src->sink pads. > >>> > >>> However it might make sense for some subdevices to support enum/get/set > >>> inputs. One example would be the analog front end subdevice for the > >>> ADV748x. By providing these ioctls, selecting the ADV748x analog inputs > >>> can be done without requiring the implementation of media entities that > >>> would define the analog source for which to establish a media link. > >>> > >>> Signed-off-by: Steve Longerbeam > >>> --- > >>> drivers/media/v4l2-core/v4l2-subdev.c | 9 +++++++++ > >>> include/media/v4l2-subdev.h | 11 +++++++++++ > >>> 2 files changed, 20 insertions(+) > >>> > >>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > >>> index 6b989fe..73fbfe9 100644 > >>> --- a/drivers/media/v4l2-core/v4l2-subdev.c > >>> +++ b/drivers/media/v4l2-core/v4l2-subdev.c > >>> @@ -378,6 +378,15 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) > >>> return -ENOTTY; > >>> return v4l2_querymenu(vfh->ctrl_handler, arg); > >>> > >>> + case VIDIOC_ENUMINPUT: > >>> + return v4l2_subdev_call(sd, video, enuminput, arg); > >>> + > >>> + case VIDIOC_G_INPUT: > >>> + return v4l2_subdev_call(sd, video, g_input, arg); > >>> + > >>> + case VIDIOC_S_INPUT: > >>> + return v4l2_subdev_call(sd, video, s_input, *(u32 *)arg); > >>> + > >>> case VIDIOC_G_CTRL: > >>> if (!vfh->ctrl_handler) > >>> return -ENOTTY; > >>> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h > >>> index f7fe78a..6e1a9cd 100644 > >>> --- a/include/media/v4l2-subdev.h > >>> +++ b/include/media/v4l2-subdev.h > >>> @@ -383,6 +383,14 @@ struct v4l2_mbus_frame_desc { > >>> * @g_input_status: get input status. Same as the status field in the > >>> * &struct &v4l2_input > >>> * > >>> + * @enuminput: enumerate inputs. Should return the same input status as > >>> + * @g_input_status if the passed input index is the currently active > >>> + * input. > >>> + * > >>> + * @g_input: returns the currently active input index. > >>> + * > >>> + * @s_input: set the active input. > >>> + * > >>> * @s_stream: used to notify the driver that a video stream will start or has > >>> * stopped. > >>> * > >>> @@ -423,6 +431,9 @@ struct v4l2_subdev_video_ops { > >>> int (*g_tvnorms)(struct v4l2_subdev *sd, v4l2_std_id *std); > >>> int (*g_tvnorms_output)(struct v4l2_subdev *sd, v4l2_std_id *std); > >>> int (*g_input_status)(struct v4l2_subdev *sd, u32 *status); > >>> + int (*enuminput)(struct v4l2_subdev *sd, struct v4l2_input *input); > >>> + int (*g_input)(struct v4l2_subdev *sd, u32 *index); > >>> + int (*s_input)(struct v4l2_subdev *sd, u32 index); > >>> int (*s_stream)(struct v4l2_subdev *sd, int enable); > >>> int (*g_pixelaspect)(struct v4l2_subdev *sd, struct v4l2_fract *aspect); > >>> int (*g_frame_interval)(struct v4l2_subdev *sd, > -- Regards, Laurent Pinchart