drm/bridge/sii8620: Fix link mode selection

Current link mode values do not allow to enable packed pixel modes.

Select packed pixel clock mode, if needed, every time the link mode
register gets updated.
Signed-off-by: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1530204243-6370-4-git-send-email-m.purski@samsung.com

drivers/gpu/drm/bridge/sil-sii8620.c

@@ -1165,8 +1165,14 @@ static void sii8620_start_video(struct sii8620 *ctx)
 	sii8620_set_format(ctx);
 
 	if (!sii8620_is_mhl3(ctx)) {
-		sii8620_mt_write_stat(ctx, MHL_DST_REG(LINK_MODE),
-			MHL_DST_LM_CLK_MODE_NORMAL | MHL_DST_LM_PATH_ENABLED);
+		u8 link_mode = MHL_DST_LM_PATH_ENABLED;
+
+		if (ctx->use_packed_pixel)
+			link_mode |= MHL_DST_LM_CLK_MODE_PACKED_PIXEL;
+		else
+			link_mode |= MHL_DST_LM_CLK_MODE_NORMAL;
+
+		sii8620_mt_write_stat(ctx, MHL_DST_REG(LINK_MODE), link_mode);
 		sii8620_set_auto_zone(ctx);
 	} else {
 		static const struct {
@@ -1677,14 +1683,18 @@ static void sii8620_status_dcap_ready(struct sii8620 *ctx)
 
 static void sii8620_status_changed_path(struct sii8620 *ctx)
 {
-	if (ctx->stat[MHL_DST_LINK_MODE] & MHL_DST_LM_PATH_ENABLED) {
-		sii8620_mt_write_stat(ctx, MHL_DST_REG(LINK_MODE),
-				      MHL_DST_LM_CLK_MODE_NORMAL
-				      | MHL_DST_LM_PATH_ENABLED);
-	} else {
+	u8 link_mode;
+
+	if (ctx->use_packed_pixel)
+		link_mode = MHL_DST_LM_CLK_MODE_PACKED_PIXEL;
+	else
+		link_mode = MHL_DST_LM_CLK_MODE_NORMAL;
+
+	if (ctx->stat[MHL_DST_LINK_MODE] & MHL_DST_LM_PATH_ENABLED)
+		link_mode |= MHL_DST_LM_PATH_ENABLED;
+
 	sii8620_mt_write_stat(ctx, MHL_DST_REG(LINK_MODE),
-				      MHL_DST_LM_CLK_MODE_NORMAL);
-	}
+			      link_mode);
 }
 
 static void sii8620_msc_mr_write_stat(struct sii8620 *ctx)