Because the current Tegra video driver is video-centric, it exposes all
controls via /dev/video. If both the camera sensor and the VI provide
hflip and vflip, the driver will fail because only one control is allowed.
To address this, hflip and vflip should be added from the SoC only if the
camera sensor doesn't provide those controls.

Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # tegra20, parallel camera
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/staging/media/tegra-video/vi.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
index 70a84158b589..0f98157a7e91 100644
--- a/drivers/staging/media/tegra-video/vi.c
+++ b/drivers/staging/media/tegra-video/vi.c
@@ -962,6 +962,7 @@ static int tegra_channel_setup_ctrl_handler(struct tegra_vi_channel *chan)
 	}
 #else
 	struct v4l2_subdev *subdev;
+	struct v4l2_ctrl *hflip, *vflip;
 
 	/* custom control */
 	v4l2_ctrl_new_custom(&chan->ctrl_handler, &syncpt_timeout_ctrl, NULL);
@@ -987,11 +988,13 @@ static int tegra_channel_setup_ctrl_handler(struct tegra_vi_channel *chan)
 		return ret;
 	}
 
-	if (chan->vi->soc->has_h_v_flip) {
+	hflip = v4l2_ctrl_find(subdev->ctrl_handler, V4L2_CID_HFLIP);
+	if (chan->vi->soc->has_h_v_flip && !hflip)
 		v4l2_ctrl_new_std(&chan->ctrl_handler, &vi_ctrl_ops, V4L2_CID_HFLIP, 0, 1, 1, 0);
-		v4l2_ctrl_new_std(&chan->ctrl_handler, &vi_ctrl_ops, V4L2_CID_VFLIP, 0, 1, 1, 0);
-	}
 
+	vflip = v4l2_ctrl_find(subdev->ctrl_handler, V4L2_CID_VFLIP);
+	if (chan->vi->soc->has_h_v_flip && !vflip)
+		v4l2_ctrl_new_std(&chan->ctrl_handler, &vi_ctrl_ops, V4L2_CID_VFLIP, 0, 1, 1, 0);
 #endif
 
 	/* setup the controls */
-- 
2.51.0