[media] vivid: fix test pattern movement for V4L2_FIELD_ALTERNATE

The successive TOP/BOTTOM fields did not move as they should: only
every other field actually changed position.

The cause was that the tpg needs to know if it is dealing with a
FIELD_ALTERNATE case since that requires slightly different handling.

So tell the TPG whether or not the field setting is for the ALTERNATE
case or not.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/vivid/vivid-kthread-cap.c

@@ -436,7 +436,8 @@ static void vivid_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf)
 	} else {
 		buf->vb.v4l2_buf.field = dev->field_cap;
 	}
-	tpg_s_field(&dev->tpg, buf->vb.v4l2_buf.field);
+	tpg_s_field(&dev->tpg, buf->vb.v4l2_buf.field,
+		    dev->field_cap == V4L2_FIELD_ALTERNATE);
 	tpg_s_perc_fill_blank(&dev->tpg, dev->must_blank[buf->vb.v4l2_buf.index]);
 
 	vivid_precalc_copy_rects(dev);

drivers/media/platform/vivid/vivid-tpg.c

@@ -1413,7 +1413,9 @@ void tpg_fillbuffer(struct tpg_data *tpg, v4l2_std_id std, unsigned p, u8 *vbuf)
 			linestart_older += line_offset;
 			linestart_newer += line_offset;
 		}
-		if (is_60hz) {
+		if (tpg->field_alternate) {
+			linestart_top = linestart_bottom = linestart_older;
+		} else if (is_60hz) {
 			linestart_top = linestart_newer;
 			linestart_bottom = linestart_older;
 		} else {

drivers/media/platform/vivid/vivid-tpg.h

@@ -98,6 +98,7 @@ struct tpg_data {
 	/* Scaled output frame size */
 	unsigned			scaled_width;
 	u32				field;
+	bool				field_alternate;
 	/* crop coordinates are frame-based */
 	struct v4l2_rect		crop;
 	/* compose coordinates are format-based */
@@ -348,9 +349,10 @@ static inline void tpg_s_buf_height(struct tpg_data *tpg, unsigned h)
 	tpg->buf_height = h;
 }
 
-static inline void tpg_s_field(struct tpg_data *tpg, unsigned field)
+static inline void tpg_s_field(struct tpg_data *tpg, unsigned field, bool alternate)
 {
 	tpg->field = field;
+	tpg->field_alternate = alternate;
 }
 
 static inline void tpg_s_perc_fill(struct tpg_data *tpg,

drivers/media/platform/vivid/vivid-vid-cap.c

@@ -733,7 +733,10 @@ int vivid_s_fmt_vid_cap(struct file *file, void *priv,
 	if (tpg_g_planes(&dev->tpg) > 1)
 		tpg_s_bytesperline(&dev->tpg, 1, mp->plane_fmt[1].bytesperline);
 	dev->field_cap = mp->field;
-	tpg_s_field(&dev->tpg, dev->field_cap);
+	if (dev->field_cap == V4L2_FIELD_ALTERNATE)
+		tpg_s_field(&dev->tpg, V4L2_FIELD_TOP, true);
+	else
+		tpg_s_field(&dev->tpg, dev->field_cap, false);
 	tpg_s_crop_compose(&dev->tpg, &dev->crop_cap, &dev->compose_cap);
 	tpg_s_fourcc(&dev->tpg, dev->fmt_cap->fourcc);
 	if (vivid_is_sdtv_cap(dev))