[media] vivid: add support to set CVT, GTF timings

In addition to v4l2_find_dv_timings_cap(), where timings are searched
against the list of preset timings, the incoming timing from v4l2-ctl
is checked against CVT and GTF standards. If it confirms to be CVT or
GTF, it is treated as valid timing and vivid format is updated with
new timings.
Signed-off-by: Prashant Laddha <prladdha@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

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

@@ -1578,6 +1578,65 @@ int vivid_vid_cap_s_std(struct file *file, void *priv, v4l2_std_id id)
 	return 0;
 }
 
+static void find_aspect_ratio(u32 width, u32 height,
+			       u32 *num, u32 *denom)
+{
+	if (!(height % 3) && ((height * 4 / 3) == width)) {
+		*num = 4;
+		*denom = 3;
+	} else if (!(height % 9) && ((height * 16 / 9) == width)) {
+		*num = 16;
+		*denom = 9;
+	} else if (!(height % 10) && ((height * 16 / 10) == width)) {
+		*num = 16;
+		*denom = 10;
+	} else if (!(height % 4) && ((height * 5 / 4) == width)) {
+		*num = 5;
+		*denom = 4;
+	} else if (!(height % 9) && ((height * 15 / 9) == width)) {
+		*num = 15;
+		*denom = 9;
+	} else { /* default to 16:9 */
+		*num = 16;
+		*denom = 9;
+	}
+}
+
+static bool valid_cvt_gtf_timings(struct v4l2_dv_timings *timings)
+{
+	struct v4l2_bt_timings *bt = &timings->bt;
+	u32 total_h_pixel;
+	u32 total_v_lines;
+	u32 h_freq;
+
+	if (!v4l2_valid_dv_timings(timings, &vivid_dv_timings_cap,
+				NULL, NULL))
+		return false;
+
+	total_h_pixel = V4L2_DV_BT_FRAME_WIDTH(bt);
+	total_v_lines = V4L2_DV_BT_FRAME_HEIGHT(bt);
+
+	h_freq = (u32)bt->pixelclock / total_h_pixel;
+
+	if (bt->standards == 0 || (bt->standards & V4L2_DV_BT_STD_CVT)) {
+		if (v4l2_detect_cvt(total_v_lines, h_freq, bt->vsync,
+				    bt->polarities, timings))
+			return true;
+	}
+
+	if (bt->standards == 0 || (bt->standards & V4L2_DV_BT_STD_GTF)) {
+		struct v4l2_fract aspect_ratio;
+
+		find_aspect_ratio(bt->width, bt->height,
+				  &aspect_ratio.numerator,
+				  &aspect_ratio.denominator);
+		if (v4l2_detect_gtf(total_v_lines, h_freq, bt->vsync,
+				    bt->polarities, aspect_ratio, timings))
+			return true;
+	}
+	return false;
+}
+
 int vivid_vid_cap_s_dv_timings(struct file *file, void *_fh,
 				    struct v4l2_dv_timings *timings)
 {
@@ -1586,12 +1645,15 @@ int vivid_vid_cap_s_dv_timings(struct file *file, void *_fh,
 	if (!vivid_is_hdmi_cap(dev))
 		return -ENODATA;
 	if (!v4l2_find_dv_timings_cap(timings, &vivid_dv_timings_cap,
-				0, NULL, NULL))
+				      0, NULL, NULL) &&
+	    !valid_cvt_gtf_timings(timings))
 		return -EINVAL;
+
 	if (v4l2_match_dv_timings(timings, &dev->dv_timings_cap, 0))
 		return 0;
 	if (vb2_is_busy(&dev->vb_vid_cap_q))
 		return -EBUSY;
+
 	dev->dv_timings_cap = *timings;
 	vivid_update_format_cap(dev, false);
 	return 0;