[PATCH 2/6] drm: bridge: dw-hdmi: Implement connector atomic_begin/atomic_flush

[Algea Cao]

Introduce dw_hdmi_connector_atomic_begin() and
dw_hdmi_connector_atomic_flush() to implement connector
atomic_begin/atomic_flush. When enc_out_bus_format or
enc_in_bus_format changed, dw_hdmi_setup is called.

To avoid screen flash when updating bus format, it's need
to send AVMUTE flag to make screen black, and clear flag
after bus format updated.

Signed-off-by: Algea Cao <algea.cao@xxxxxxxxxxxxxx>
---

 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 65 +++++++++++++++++++++++
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.h |  4 ++
 2 files changed, 69 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 6148a022569a..a1a81fc768c2 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -108,6 +108,8 @@ struct hdmi_vmode {
 };
 
 struct hdmi_data_info {
+	unsigned int prev_enc_in_bus_format;
+	unsigned int prev_enc_out_bus_format;
 	unsigned int enc_in_bus_format;
 	unsigned int enc_out_bus_format;
 	unsigned int enc_in_encoding;
@@ -116,6 +118,7 @@ struct hdmi_data_info {
 	unsigned int hdcp_enable;
 	struct hdmi_vmode video_mode;
 	bool rgb_limited_range;
+	bool update;
 };
 
 struct dw_hdmi_i2c {
@@ -2401,6 +2404,60 @@ static int dw_hdmi_connector_get_modes(struct drm_connector *connector)
 	return ret;
 }
 
+static void
+dw_hdmi_connector_atomic_begin(struct drm_connector *connector,
+			       struct drm_connector_state *conn_state)
+{
+	struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
+					    connector);
+	unsigned int enc_in_bus_fmt = hdmi->hdmi_data.enc_in_bus_format;
+	unsigned int enc_out_bus_fmt = hdmi->hdmi_data.enc_out_bus_format;
+	unsigned int prev_enc_in_bus_fmt =
+		hdmi->hdmi_data.prev_enc_in_bus_format;
+	unsigned int prev_enc_out_bus_fmt =
+		hdmi->hdmi_data.prev_enc_out_bus_format;
+
+	if (!conn_state->crtc)
+		return;
+
+	if (!hdmi->hdmi_data.video_mode.mpixelclock)
+		return;
+
+	if (enc_in_bus_fmt != prev_enc_in_bus_fmt ||
+	    enc_out_bus_fmt != prev_enc_out_bus_fmt) {
+		hdmi->hdmi_data.update = true;
+		hdmi_writeb(hdmi, HDMI_FC_GCP_SET_AVMUTE, HDMI_FC_GCP);
+		/* Add delay to make av mute work on sink*/
+		msleep(50);
+	} else {
+		hdmi->hdmi_data.update = false;
+	}
+}
+
+static void
+dw_hdmi_connector_atomic_flush(struct drm_connector *connector,
+			       struct drm_connector_state *conn_state)
+{
+	struct dw_hdmi *hdmi = container_of(connector, struct dw_hdmi,
+					     connector);
+
+	if (!conn_state->crtc)
+		return;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	if (hdmi->hdmi_data.update) {
+		dw_hdmi_setup(hdmi, hdmi->curr_conn, &hdmi->previous_mode);
+		/*
+		 * Before clear AVMUTE, delay is needed to
+		 * prevent display flash.
+		 */
+		msleep(50);
+		hdmi_writeb(hdmi, HDMI_FC_GCP_CLEAR_AVMUTE, HDMI_FC_GCP);
+		hdmi->hdmi_data.update = false;
+	}
+}
+
 static bool hdr_metadata_equal(const struct drm_connector_state *old_state,
 			       const struct drm_connector_state *new_state)
 {
@@ -2465,6 +2522,8 @@ static const struct drm_connector_funcs dw_hdmi_connector_funcs = {
 static const struct drm_connector_helper_funcs dw_hdmi_connector_helper_funcs = {
 	.get_modes = dw_hdmi_connector_get_modes,
 	.atomic_check = dw_hdmi_connector_atomic_check,
+	.atomic_begin = dw_hdmi_connector_atomic_begin,
+	.atomic_flush = dw_hdmi_connector_atomic_flush,
 };
 
 static int dw_hdmi_connector_create(struct dw_hdmi *hdmi)
@@ -2778,6 +2837,12 @@ static int dw_hdmi_bridge_atomic_check(struct drm_bridge *bridge,
 {
 	struct dw_hdmi *hdmi = bridge->driver_private;
 
+	hdmi->hdmi_data.prev_enc_out_bus_format =
+			hdmi->hdmi_data.enc_out_bus_format;
+
+	hdmi->hdmi_data.prev_enc_in_bus_format =
+			hdmi->hdmi_data.enc_in_bus_format;
+
 	hdmi->hdmi_data.enc_out_bus_format =
 			bridge_state->output_bus_cfg.format;
 
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
index 1999db05bc3b..05182418efbb 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
@@ -842,6 +842,10 @@ enum {
 	HDMI_FC_AVICONF3_QUANT_RANGE_LIMITED = 0x00,
 	HDMI_FC_AVICONF3_QUANT_RANGE_FULL = 0x04,
 
+/* HDMI_FC_GCP */
+	HDMI_FC_GCP_SET_AVMUTE = 0x2,
+	HDMI_FC_GCP_CLEAR_AVMUTE = 0x1,
+
 /* FC_DBGFORCE field values */
 	HDMI_FC_DBGFORCE_FORCEAUDIO = 0x10,
 	HDMI_FC_DBGFORCE_FORCEVIDEO = 0x1,
-- 
2.25.1