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From:   Ramzi BEN MEFTAH <rbmeftah@de.adit-jv.com>
To:     Kieran Bingham <kieran.bingham@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hans.verkuil@cisco.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Janusz Krzysztofik <jmkrzyszt@gmail.com>,
        Jacopo Mondi <jacopo@jmondi.org>,
        Steve Longerbeam <steve_longerbeam@mentor.com>,
        Ezequiel Garcia <ezequiel@collabora.com>,
        Arnd Bergmann <arnd@arndb.de>, <linux-media@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     Michael Rodin <mrodin@de.adit-jv.com>, <efriedrich@de.adit-jv.com>,
        <erosca@de.adit-jv.com>
Subject: [PATCH 1/3] v4l2-subdev: Add subdev ioctl support for ENUM/GET/SET INPUT
Date:   Tue, 16 Jun 2020 12:00:15 +0200
Message-ID: <1592301619-17631-1-git-send-email-rbmeftah@de.adit-jv.com>
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From: Steve Longerbeam <steve_longerbeam@mentor.com>

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 <steve_longerbeam@mentor.com>
---
 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,
-- 
2.7.4