[media] vivid: Fix YUV555 and YUV565 handling

precalculate_color() had a optimization that avoided duplicated
conversion for YUV formats. This optimization did not take into
consideration YUV444, YUV555, YUV565 or limited range quantization.

This patch keeps the optimization, but fixes the wrong handling.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/common/v4l2-tpg/v4l2-tpg-core.c

@@ -795,6 +795,8 @@ static void precalculate_color(struct tpg_data *tpg, int k)
 	int r = tpg_colors[col].r;
 	int g = tpg_colors[col].g;
 	int b = tpg_colors[col].b;
+	int y, cb, cr;
+	bool ycbcr_valid = false;
 
 	if (k == TPG_COLOR_TEXTBG) {
 		col = tpg_get_textbg_color(tpg);
@@ -871,7 +873,6 @@ static void precalculate_color(struct tpg_data *tpg, int k)
 	     tpg->saturation != 128 || tpg->hue) &&
 	    tpg->color_enc != TGP_COLOR_ENC_LUMA) {
 		/* Implement these operations */
-		int y, cb, cr;
 		int tmp_cb, tmp_cr;
 
 		/* First convert to YCbCr */
@@ -888,12 +889,9 @@ static void precalculate_color(struct tpg_data *tpg, int k)
 
 		cb = (128 << 4) + (tmp_cb * tpg->contrast * tpg->saturation) / (128 * 128);
 		cr = (128 << 4) + (tmp_cr * tpg->contrast * tpg->saturation) / (128 * 128);
-		if (tpg->color_enc == TGP_COLOR_ENC_YCBCR) {
-			tpg->colors[k][0] = clamp(y >> 4, 1, 254);
-			tpg->colors[k][1] = clamp(cb >> 4, 1, 254);
-			tpg->colors[k][2] = clamp(cr >> 4, 1, 254);
-			return;
-		}
+		if (tpg->color_enc == TGP_COLOR_ENC_YCBCR)
+			ycbcr_valid = true;
+		else
 			ycbcr_to_color(tpg, y, cb, cr, &r, &g, &b);
 	} else if ((tpg->brightness != 128 || tpg->contrast != 128) &&
 		   tpg->color_enc == TGP_COLOR_ENC_LUMA) {
@@ -915,8 +913,7 @@ static void precalculate_color(struct tpg_data *tpg, int k)
 	case TGP_COLOR_ENC_YCBCR:
 	{
 		/* Convert to YCbCr */
-		int y, cb, cr;
-
+		if (!ycbcr_valid)
 			color_to_ycbcr(tpg, r, g, b, &y, &cb, &cr);
 
 		if (tpg->real_quantization == V4L2_QUANTIZATION_LIM_RANGE) {