media: adv7180: fix frame interval in progressive mode

[ Upstream commit 90289b67c5c1d4c18784059b27460d292e16d208 ]

The ADV7280-M may internally convert interlaced video input to
progressive video. If this mode is enabled, the ADV7280-M delivers
progressive video frames at the field rate of 50 fields per second (PAL)
or 60 fields per second (NTSC).

Fix the reported frame interval if progressive video is enabled.

Signed-off-by: Thorsten Schmelzer <tschmelzer@topcon.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 45d9a0cd1b88d1be08eb07df5df8804bad525762)
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Author: Thorsten Schmelzer

drivers/media/i2c/adv7180.c

@@ -471,6 +471,13 @@ static int adv7180_g_frame_interval(struct v4l2_subdev *sd,
 		fi->interval.denominator = 25;
 	}
 
+	/*
+	 * If the de-interlacer is active, the chip produces full video frames
+	 * at the field rate.
+	 */
+	if (state->field == V4L2_FIELD_NONE)
+		fi->interval.denominator *= 2;
+
 	return 0;
 }