From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:35878 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756008Ab3C0BKf (ORCPT ); Tue, 26 Mar 2013 21:10:35 -0400 From: Laurent Pinchart To: Hans Verkuil Cc: linux-media@vger.kernel.org, Ezequiel Garcia , Frank Schaefer , Mauro Carvalho Chehab , Hans Verkuil Subject: Re: [RFC PATCH 2/6] v4l2: add new VIDIOC_DBG_G_CHIP_NAME ioctl. Date: Wed, 27 Mar 2013 02:11:23 +0100 Message-ID: <4375309.Kgln0QGpEZ@avalon> In-Reply-To: <1363624700-29270-3-git-send-email-hverkuil@xs4all.nl> References: <1363624700-29270-1-git-send-email-hverkuil@xs4all.nl> <1363624700-29270-3-git-send-email-hverkuil@xs4all.nl> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Hans, On Monday 18 March 2013 17:38:16 Hans Verkuil wrote: > From: Hans Verkuil > > Simplify the debugging ioctls by creating the VIDIOC_DBG_G_CHIP_NAME ioctl. > This will eventually replace VIDIOC_DBG_G_CHIP_IDENT. Chip matching is done > by the name or index of subdevices or an index to a bridge chip. Most of > this can all be done automatically, so most drivers just need to provide > get/set register ops. > > In particular, it is now possible to get/set subdev registers without > requiring assistance of the bridge driver. My biggest question is why don't we use the media controller API to get the information provided by this new ioctl ? > Signed-off-by: Hans Verkuil > --- > drivers/media/v4l2-core/v4l2-common.c | 5 +- > drivers/media/v4l2-core/v4l2-dev.c | 5 +- > drivers/media/v4l2-core/v4l2-ioctl.c | 115 ++++++++++++++++++++++++++++-- > include/media/v4l2-ioctl.h | 3 + > include/uapi/linux/videodev2.h | 34 +++++++--- > 5 files changed, 146 insertions(+), 16 deletions(-) [snip] > diff --git a/drivers/media/v4l2-core/v4l2-dev.c > b/drivers/media/v4l2-core/v4l2-dev.c index de1e9ab..c0c651d 100644 > --- a/drivers/media/v4l2-core/v4l2-dev.c > +++ b/drivers/media/v4l2-core/v4l2-dev.c > @@ -591,9 +591,10 @@ static void determine_valid_ioctls(struct video_device [snip] > +static int v4l_dbg_g_chip_name(const struct v4l2_ioctl_ops *ops, > + struct file *file, void *fh, void *arg) As this is a debug ioctl that should never be used in application, I would like to guard the whole implementation with #ifdef CONFIG_VIDEO_ADV_DEBUG. This will make sure that no applications will abuse it, as it won't be available in distro kernels. > +{ > + struct video_device *vfd = video_devdata(file); > + struct v4l2_dbg_chip_name *p = arg; > + struct v4l2_subdev *sd; > + int idx = 0; > + > + switch (p->match.type) { > + case V4L2_CHIP_MATCH_BRIDGE: > +#ifdef CONFIG_VIDEO_ADV_DEBUG > + if (ops->vidioc_s_register) > + p->flags |= V4L2_CHIP_FL_WRITABLE; > + if (ops->vidioc_g_register) > + p->flags |= V4L2_CHIP_FL_READABLE; > +#endif > + if (ops->vidioc_g_chip_name) > + return ops->vidioc_g_chip_name(file, fh, arg); > + if (p->match.addr) > + return -EINVAL; > + if (vfd->v4l2_dev) > + strlcpy(p->name, vfd->v4l2_dev->name, sizeof(p->name)); > + else if (vfd->parent) > + strlcpy(p->name, vfd->parent->driver->name, sizeof(p->name)); > + else > + strlcpy(p->name, "bridge", sizeof(p->name)); > + return 0; > + > + case V4L2_CHIP_MATCH_SUBDEV_IDX: > + case V4L2_CHIP_MATCH_SUBDEV_NAME: > + if (vfd->v4l2_dev == NULL) > + break; > + v4l2_device_for_each_subdev(sd, vfd->v4l2_dev) { > + if (v4l_dbg_found_match(&p->match, sd, idx++)) { > +#ifdef CONFIG_VIDEO_ADV_DEBUG > + if (sd->ops->core && sd->ops->core->s_register) > + p->flags |= V4L2_CHIP_FL_WRITABLE; > + if (sd->ops->core && sd->ops->core->g_register) > + p->flags |= V4L2_CHIP_FL_READABLE; > +#endif > + strlcpy(p->name, sd->name, sizeof(p->name)); > + return 0; > + } > + } > + break; > + } > + return -EINVAL; > +} -- Regards, Laurent Pinchart