[media] v4l2-dv-timings: add interlace support in detect cvt/gtf

Extend detect_cvt/gtf API to indicate the format type (interlaced
or progressive). In case of interlaced, the vertical front and back
porch and vsync values for both (odd,even) fields are considered to
derive image height. Populated vsync, vertical front, back porch
values in bt timing structure for even and odd fields and updated
the flags appropriately.

Also modified the functions calling the detect_cvt/gtf(). As of now
these functions are calling detect_cvt/gtf() with interlaced flag
set to false.

Cc: Martin Bugge <[e-mail]>
Cc: Mats Randgaard <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Signed-off-by: Prashant Laddha <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/i2c/adv7604.c

···
 	if (v4l2_detect_cvt(stdi->lcf + 1, hfreq, stdi->lcvs,
 			(stdi->hs_pol == '+' ? V4L2_DV_HSYNC_POS_POL : 0) |
 			(stdi->vs_pol == '+' ? V4L2_DV_VSYNC_POS_POL : 0),
-			timings))
+			false, timings))
 		return 0;
 	if (v4l2_detect_gtf(stdi->lcf + 1, hfreq, stdi->lcvs,
 			(stdi->hs_pol == '+' ? V4L2_DV_HSYNC_POS_POL : 0) |
 			(stdi->vs_pol == '+' ? V4L2_DV_VSYNC_POS_POL : 0),
-			state->aspect_ratio, timings))
+			false, state->aspect_ratio, timings))
 		return 0;
 
 	v4l2_dbg(2, debug, sd,

drivers/media/i2c/adv7842.c

···
 	if (v4l2_detect_cvt(stdi->lcf + 1, hfreq, stdi->lcvs,
 			(stdi->hs_pol == '+' ? V4L2_DV_HSYNC_POS_POL : 0) |
 			(stdi->vs_pol == '+' ? V4L2_DV_VSYNC_POS_POL : 0),
-			    timings))
+			false, timings))
 		return 0;
 	if (v4l2_detect_gtf(stdi->lcf + 1, hfreq, stdi->lcvs,
 			(stdi->hs_pol == '+' ? V4L2_DV_HSYNC_POS_POL : 0) |
 			(stdi->vs_pol == '+' ? V4L2_DV_VSYNC_POS_POL : 0),
-			    state->aspect_ratio, timings))
+			false, state->aspect_ratio, timings))
 		return 0;
 
 	v4l2_dbg(2, debug, sd,

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

···
 
 	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))
+				    bt->polarities, false, timings))
 			return true;
 	}
 
···
 				  &aspect_ratio.numerator,
 				  &aspect_ratio.denominator);
 		if (v4l2_detect_gtf(total_v_lines, h_freq, bt->vsync,
-				    bt->polarities, aspect_ratio, timings))
+				    bt->polarities, false,
+				    aspect_ratio, timings))
 			return true;
 	}
 	return false;

drivers/media/v4l2-core/v4l2-dv-timings.c

···
  * @vsync - the height of the vertical sync in lines.
  * @polarities - the horizontal and vertical polarities (same as struct
  *		v4l2_bt_timings polarities).
+ * @interlaced - if this flag is true, it indicates interlaced format
  * @fmt - the resulting timings.
  *
  * This function will attempt to detect if the given values correspond to a
···
  * detection function.
  */
 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
-		u32 polarities, struct v4l2_dv_timings *fmt)
+		u32 polarities, bool interlaced, struct v4l2_dv_timings *fmt)
 {
 	int  v_fp, v_bp, h_fp, h_bp, hsync;
 	int  frame_width, image_height, image_width;
···
 		if (v_bp < CVT_MIN_V_BPORCH)
 			v_bp = CVT_MIN_V_BPORCH;
 	}
-	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
+
+	if (interlaced)
+		image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
+	else
+		image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 
 	if (image_height < 0)
 		return false;
···
 	fmt->bt.hsync = hsync;
 	fmt->bt.vsync = vsync;
 	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
-	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
+
+	if (!interlaced) {
+		fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
+		fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
+	} else {
+		fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
+				      2 * vsync) / 2;
+		fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
+					2 * vsync - fmt->bt.vbackporch;
+		fmt->bt.il_vfrontporch = v_fp;
+		fmt->bt.il_vsync = vsync;
+		fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
+		fmt->bt.interlaced = V4L2_DV_INTERLACED;
+	}
+
 	fmt->bt.pixelclock = pix_clk;
 	fmt->bt.standards = V4L2_DV_BT_STD_CVT;
+
 	if (reduced_blanking)
 		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
+
 	return true;
 }
 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
···
  * @vsync - the height of the vertical sync in lines.
  * @polarities - the horizontal and vertical polarities (same as struct
  *		v4l2_bt_timings polarities).
+ * @interlaced - if this flag is true, it indicates interlaced format
  * @aspect - preferred aspect ratio. GTF has no method of determining the
  *		aspect ratio in order to derive the image width from the
  *		image height, so it has to be passed explicitly. Usually
···
 		unsigned hfreq,
 		unsigned vsync,
 		u32 polarities,
+		bool interlaced,
 		struct v4l2_fract aspect,
 		struct v4l2_dv_timings *fmt)
 {
···
 
 	/* Vertical */
 	v_fp = GTF_V_FP;
-
 	v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync;
-	image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
+	if (interlaced)
+		image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
+	else
+		image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 
 	if (image_height < 0)
 		return false;
···
 	fmt->bt.hsync = hsync;
 	fmt->bt.vsync = vsync;
 	fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
-	fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
+
+	if (!interlaced) {
+		fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
+		fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
+	} else {
+		fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
+				      2 * vsync) / 2;
+		fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
+					2 * vsync - fmt->bt.vbackporch;
+		fmt->bt.il_vfrontporch = v_fp;
+		fmt->bt.il_vsync = vsync;
+		fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
+		fmt->bt.interlaced = V4L2_DV_INTERLACED;
+	}
+
 	fmt->bt.pixelclock = pix_clk;
 	fmt->bt.standards = V4L2_DV_BT_STD_GTF;
+
 	if (!default_gtf)
 		fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
+
 	return true;
 }
 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);

include/media/v4l2-dv-timings.h

···
  * @vsync - the height of the vertical sync in lines.
  * @polarities - the horizontal and vertical polarities (same as struct
  *		v4l2_bt_timings polarities).
+ * @interlaced - if this flag is true, it indicates interlaced format
  * @fmt - the resulting timings.
  *
  * This function will attempt to detect if the given values correspond to a
···
  * in with the found CVT timings.
  */
 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync,
-		u32 polarities, struct v4l2_dv_timings *fmt);
+		u32 polarities, bool interlaced, struct v4l2_dv_timings *fmt);
 
 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
  * @frame_height - the total height of the frame (including blanking) in lines.
···
  * @vsync - the height of the vertical sync in lines.
  * @polarities - the horizontal and vertical polarities (same as struct
  *		v4l2_bt_timings polarities).
+ * @interlaced - if this flag is true, it indicates interlaced format
  * @aspect - preferred aspect ratio. GTF has no method of determining the
  *		aspect ratio in order to derive the image width from the
  *		image height, so it has to be passed explicitly. Usually
···
  * in with the found GTF timings.
  */
 bool v4l2_detect_gtf(unsigned frame_height, unsigned hfreq, unsigned vsync,
-		u32 polarities, struct v4l2_fract aspect,
+		u32 polarities, bool interlaced, struct v4l2_fract aspect,
 		struct v4l2_dv_timings *fmt);
 
 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes