From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-vbr8.xs4all.nl ([194.109.24.28]:2881 "EHLO smtp-vbr8.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754044Ab0GGMnO (ORCPT ); Wed, 7 Jul 2010 08:43:14 -0400 Message-ID: In-Reply-To: <1278503608-9126-3-git-send-email-laurent.pinchart@ideasonboard.com> References: <1278503608-9126-1-git-send-email-laurent.pinchart@ideasonboard.com> <1278503608-9126-3-git-send-email-laurent.pinchart@ideasonboard.com> Date: Wed, 7 Jul 2010 14:43:08 +0200 Subject: Re: [RFC/PATCH 2/6] v4l: subdev: Add device node support From: "Hans Verkuil" To: "Laurent Pinchart" Cc: linux-media@vger.kernel.org, sakari.ailus@maxwell.research.nokia.com MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-media-owner@vger.kernel.org List-ID: > Create a device node named subdevX for every registered subdev. > > As the device node is registered before the subdev core::s_config > function is called, return -EGAIN on open until initialization > completes. > > Signed-off-by: Laurent Pinchart > Signed-off-by: Vimarsh Zutshi > --- > drivers/media/video/Makefile | 2 +- > drivers/media/video/v4l2-common.c | 3 ++ > drivers/media/video/v4l2-dev.c | 5 +++ > drivers/media/video/v4l2-device.c | 27 +++++++++++++++- > drivers/media/video/v4l2-subdev.c | 65 > +++++++++++++++++++++++++++++++++++++ > include/media/v4l2-dev.h | 3 +- > include/media/v4l2-subdev.h | 10 ++++++ > 7 files changed, 112 insertions(+), 3 deletions(-) ... > diff --git a/drivers/media/video/v4l2-device.c > b/drivers/media/video/v4l2-device.c > index 5a7dc4a..685fa82 100644 > --- a/drivers/media/video/v4l2-device.c > +++ b/drivers/media/video/v4l2-device.c > @@ -115,18 +115,40 @@ EXPORT_SYMBOL_GPL(v4l2_device_unregister); > int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, > struct v4l2_subdev *sd) > { > + struct video_device *vdev; > + int ret; > + > /* Check for valid input */ > if (v4l2_dev == NULL || sd == NULL || !sd->name[0]) > return -EINVAL; > + > /* Warn if we apparently re-register a subdev */ > WARN_ON(sd->v4l2_dev != NULL); > + > if (!try_module_get(sd->owner)) > return -ENODEV; > + > sd->v4l2_dev = v4l2_dev; > spin_lock(&v4l2_dev->lock); > list_add_tail(&sd->list, &v4l2_dev->subdevs); > spin_unlock(&v4l2_dev->lock); > - return 0; > + > + /* Register the device node. */ > + vdev = &sd->devnode; > + snprintf(vdev->name, sizeof(vdev->name), "subdev"); > + vdev->parent = v4l2_dev->dev; > + vdev->fops = &v4l2_subdev_fops; > + vdev->release = video_device_release_empty; > + ret = video_register_device(vdev, VFL_TYPE_SUBDEV, -1); > + if (ret < 0) { > + spin_lock(&v4l2_dev->lock); > + list_del(&sd->list); > + spin_unlock(&v4l2_dev->lock); > + sd->v4l2_dev = NULL; > + module_put(sd->owner); > + } > + > + return ret; > } > EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); > I'm missing one thing here: in this code the subdev device node is always registered. But for most subdev drivers there is no need for a device node. This should really be explicitly turned on by the subdev driver itself. Regards, Hans -- Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco