drm/bridge/sii8620: add DVI mode support

If the sink device is in HDMI mode, enable infoframe interrupt in scdt
irq handle function else call start_video function immediately, because
in DVI mode, there is no infoframe interrupt provided.

Rename start_hdmi function to start_video and get rid of the old
start_video function. In start_video, if the sink is DVI and mode is
MHL1 or MHl2, write appropriate values to registers else the path
should remain the same as in HDMI mode.
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/1510224822-7732-1-git-send-email-m.purski@samsung.com

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

@@ -1169,8 +1169,18 @@ static void sii8620_set_infoframes(struct sii8620 *ctx)
 	sii8620_write_buf(ctx, REG_TPI_INFO_B0, buf, ret);
 }
 
-static void sii8620_start_hdmi(struct sii8620 *ctx)
+static void sii8620_start_video(struct sii8620 *ctx)
 {
+	if (!sii8620_is_mhl3(ctx))
+		sii8620_stop_video(ctx);
+
+	if (ctx->sink_type == SINK_DVI && !sii8620_is_mhl3(ctx)) {
+		sii8620_write(ctx, REG_RX_HDMI_CTRL2,
+			      VAL_RX_HDMI_CTRL2_DEFVAL);
+		sii8620_write(ctx, REG_TPI_SC, 0);
+		return;
+	}
+
 	sii8620_write_seq_static(ctx,
 		REG_RX_HDMI_CTRL2, VAL_RX_HDMI_CTRL2_DEFVAL
 			| BIT_RX_HDMI_CTRL2_USE_AV_MUTE,
@@ -1229,21 +1239,6 @@ static void sii8620_start_hdmi(struct sii8620 *ctx)
 	sii8620_set_infoframes(ctx);
 }
 
-static void sii8620_start_video(struct sii8620 *ctx)
-{
-	if (!sii8620_is_mhl3(ctx))
-		sii8620_stop_video(ctx);
-
-	switch (ctx->sink_type) {
-	case SINK_HDMI:
-		sii8620_start_hdmi(ctx);
-		break;
-	case SINK_DVI:
-	default:
-		break;
-	}
-}
-
 static void sii8620_disable_hpd(struct sii8620 *ctx)
 {
 	sii8620_setbits(ctx, REG_EDID_CTRL, BIT_EDID_CTRL_EDID_PRIME_VALID, 0);
@@ -1945,8 +1940,13 @@ static void sii8620_irq_scdt(struct sii8620 *ctx)
 	if (stat & BIT_INTR_SCDT_CHANGE) {
 		u8 cstat = sii8620_readb(ctx, REG_TMDS_CSTAT_P3);
 
-		if (cstat & BIT_TMDS_CSTAT_P3_SCDT)
+		if (cstat & BIT_TMDS_CSTAT_P3_SCDT) {
+			if (ctx->sink_type == SINK_HDMI)
+				/* enable infoframe interrupt */
 				sii8620_scdt_high(ctx);
+			else
+				sii8620_start_video(ctx);
+		}
 	}
 
 	sii8620_write(ctx, REG_INTR5, stat);