[PATCH v3 2/2] drm/bridge: ite-it66121: Select HDMI or DVI mode based on sink type

[Javier Martinez Canillas <javierm@redhat.com>]

The driver assumes that the sink type is always HDMI and unconditionally
configures the bridge in this mode and enables the transmission of AVI
infoframe packets.

But this cause issues with DVI monitors, that can fail to interpret the
video signal and lead to not having any display output.

Check the connector display information sink type to decide whether DVI or
HDMI mode should be set and if the AVI infoframes packets should be sent.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

Changes in v3:
- Move the HDMI/DVI mode set to the .atomic_enable handler (Maxime Ripard).

Changes in v2:
- Don't store the sink type in a per-commit bridge state (Maxime Ripard).

 drivers/gpu/drm/bridge/ite-it66121.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index 648ca50712df..94fd513481b5 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -182,6 +182,7 @@
 
 #define IT66121_HDMI_MODE_REG			0xC0
 #define IT66121_HDMI_MODE_HDMI			BIT(0)
+#define IT66121_HDMI_MODE_DVI			0
 
 #define IT66121_SYS_STATUS_REG			0x0E
 #define IT66121_SYS_STATUS_ACTIVE_IRQ		BIT(7)
@@ -671,15 +672,23 @@ static int it66121_set_mute(struct it66121_ctx *ctx, bool mute)
 
 static void it66121_set_tx_mode(struct it66121_ctx *ctx)
 {
+	unsigned int avi_pkt = 0;
+	unsigned int mode = IT66121_HDMI_MODE_DVI;
+	struct drm_connector *connector = ctx->connector;
+
+	if (connector->display_info.is_hdmi) {
+		mode = IT66121_HDMI_MODE_HDMI;
+		avi_pkt = IT66121_AVI_INFO_PKT_ON | IT66121_AVI_INFO_PKT_RPT;
+	}
+
 	mutex_lock(&ctx->lock);
 
-	/* Enable AVI infoframe */
-	if (regmap_write(ctx->regmap, IT66121_AVI_INFO_PKT_REG,
-			 IT66121_AVI_INFO_PKT_ON | IT66121_AVI_INFO_PKT_RPT))
+	/* Enable or disable AVI infoframe */
+	if (regmap_write(ctx->regmap, IT66121_AVI_INFO_PKT_REG, avi_pkt))
 		goto unlock;
 
-	/* Set TX mode to HDMI */
-	regmap_write(ctx->regmap, IT66121_HDMI_MODE_REG, IT66121_HDMI_MODE_HDMI);
+	/* Set TX mode to DVI or HDMI */
+	regmap_write(ctx->regmap, IT66121_HDMI_MODE_REG, mode);
 
 unlock:
 	mutex_unlock(&ctx->lock);
-- 
2.54.0