[PATCH v4 09/13] media: tegra-video: Implement V4L2 device notify callback

From: Sowjanya Komatineni
Date: Fri Dec 11 2020 - 12:06:37 EST


Implement V4L2 device notify callback to handle
V4L2_EVENT_SOURCE_CHANGE event from subdevices.

HDMI-to-CSI bridge drivers trigger V4L2_EVENT_SOURCE_CHANGE when
source DV timing changes are detected or when HDMI hotplug happens.

Runtime source parameter changes during active streaming is not
allowed and Tegra video driver calls vb2_queue_error to signal a
fatal error if a notification of this event happens during an active
streaming.

Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
---
drivers/staging/media/tegra-video/vi.c | 3 +++
drivers/staging/media/tegra-video/video.c | 18 ++++++++++++++++++
2 files changed, 21 insertions(+)

diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
index 0a85e52..d42a218 100644
--- a/drivers/staging/media/tegra-video/vi.c
+++ b/drivers/staging/media/tegra-video/vi.c
@@ -1636,6 +1636,9 @@ static int tegra_vi_graph_notify_complete(struct v4l2_async_notifier *notifier)

v4l2_set_subdev_hostdata(subdev, chan);

+ subdev = tegra_channel_get_remote_source_subdev(chan);
+ v4l2_set_subdev_hostdata(subdev, chan);
+
return 0;

unregister_video:
diff --git a/drivers/staging/media/tegra-video/video.c b/drivers/staging/media/tegra-video/video.c
index e50bd70..d966b31 100644
--- a/drivers/staging/media/tegra-video/video.c
+++ b/drivers/staging/media/tegra-video/video.c
@@ -7,6 +7,8 @@
#include <linux/module.h>
#include <linux/platform_device.h>

+#include <media/v4l2-event.h>
+
#include "video.h"

static void tegra_v4l2_dev_release(struct v4l2_device *v4l2_dev)
@@ -24,6 +26,21 @@ static void tegra_v4l2_dev_release(struct v4l2_device *v4l2_dev)
kfree(vid);
}

+static void tegra_v4l2_dev_notify(struct v4l2_subdev *sd,
+ unsigned int notification, void *arg)
+{
+ struct tegra_vi_channel *chan;
+ const struct v4l2_event *ev = arg;
+
+ if (notification != V4L2_DEVICE_NOTIFY_EVENT)
+ return;
+
+ chan = v4l2_get_subdev_hostdata(sd);
+ v4l2_event_queue(&chan->video, arg);
+ if (ev->type == V4L2_EVENT_SOURCE_CHANGE && vb2_is_streaming(&chan->queue))
+ vb2_queue_error(&chan->queue);
+}
+
static int host1x_video_probe(struct host1x_device *dev)
{
struct tegra_video_device *vid;
@@ -49,6 +66,7 @@ static int host1x_video_probe(struct host1x_device *dev)

vid->v4l2_dev.mdev = &vid->media_dev;
vid->v4l2_dev.release = tegra_v4l2_dev_release;
+ vid->v4l2_dev.notify = tegra_v4l2_dev_notify;
ret = v4l2_device_register(&dev->dev, &vid->v4l2_dev);
if (ret < 0) {
dev_err(&dev->dev,
--
2.7.4