[Intel-gfx] [PATCH 3/5] drm/i915: lspcon detection

[Shashank Sharma]

lspcon is a tricky device to detect.
When in LS mode:
	It should be detected as a HDMI device, by reading EDID, on
	I2C over Aux chanel

When in PCON mode:
	It should be detected as a DP device by reading DPCD over the
	Aux channel.

This patch accommodates these specific requirements of lspcon detection
by adding appropriate changes in I915 drivers HDMI/DP detection sequence.

Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c    | 14 ++++++++++++++
 drivers/gpu/drm/i915/intel_dp.c     | 12 ++++++++++++
 drivers/gpu/drm/i915/intel_drv.h    |  2 ++
 drivers/gpu/drm/i915/intel_hdmi.c   | 14 ++++++++++----
 drivers/gpu/drm/i915/intel_lspcon.c |  6 ++++++
 5 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index c454744..811c829 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2243,12 +2243,26 @@ static bool intel_ddi_compute_config(struct intel_encoder *encoder,
 {
 	int type = encoder->type;
 	int port = intel_ddi_get_encoder_port(encoder);
+	struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
 
 	WARN(type == INTEL_OUTPUT_UNKNOWN, "compute_config() on unknown output!\n");
 
 	if (port == PORT_A)
 		pipe_config->cpu_transcoder = TRANSCODER_EDP;
 
+	/*
+	* A digital port with active lspcon device, should be detected
+	* as HDMI when in LS mode and as DP when in PCON mode.
+	*/
+	if (is_lspcon_active(dig_port)) {
+		struct intel_lspcon *lspcon = &dig_port->lspcon;
+
+		if (lspcon->mode_of_op == DRM_LSPCON_MODE_LS)
+			type = INTEL_OUTPUT_HDMI;
+		else
+			type = INTEL_OUTPUT_DISPLAYPORT;
+	}
+
 	if (type == INTEL_OUTPUT_HDMI)
 		return intel_hdmi_compute_config(encoder, pipe_config);
 	else
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index aa9c59e..39ce16e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4276,6 +4276,18 @@ intel_dp_detect(struct drm_connector *connector, bool force)
 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
 		      connector->base.id, connector->name);
 
+	/*
+	* LSPCON is a DP->HDMI converter which should be detected as
+	* HDMI in LS mode, and DP in PCON mode. So if LSPCON is in LS
+	* mode, do not try to read DPCD, but detect as HDMI.
+	*/
+	if (is_lspcon_active(intel_dig_port)) {
+		struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
+
+		if (lspcon->mode_of_op == DRM_LSPCON_MODE_LS)
+			return lspcon_ls_mode_detect(connector, force);
+	}
+
 	if (intel_dp->is_mst) {
 		/* MST devices are disconnected from a monitor POV */
 		intel_dp_unset_edid(intel_dp);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 205a463..fa77886 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1452,6 +1452,8 @@ struct intel_hdmi *enc_to_intel_hdmi(struct drm_encoder *encoder);
 bool intel_hdmi_compute_config(struct intel_encoder *encoder,
 			       struct intel_crtc_state *pipe_config);
 void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable);
+enum drm_connector_status
+intel_hdmi_detect(struct drm_connector *connector, bool force);
 
 /* intel_lvds.c */
 void intel_lvds_init(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 6b52c6a..79184e2 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1444,15 +1444,21 @@ intel_hdmi_set_edid(struct drm_connector *connector, bool force)
 {
 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
 	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
+	struct intel_digital_port *dig_port = hdmi_to_dig_port(intel_hdmi);
+	struct i2c_adapter *adapter;
 	struct edid *edid = NULL;
 	bool connected = false;
 
 	if (force) {
 		intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
 
-		edid = drm_get_edid(connector,
-				    intel_gmbus_get_adapter(dev_priv,
-				    intel_hdmi->ddc_bus));
+		if (is_lspcon_active(dig_port))
+			adapter = &dig_port->lspcon.aux->ddc;
+		else
+			adapter = intel_gmbus_get_adapter(dev_priv,
+				intel_hdmi->ddc_bus);
+
+		edid = drm_get_edid(connector, adapter);
 
 		intel_hdmi_dp_dual_mode_detect(connector, edid != NULL);
 
@@ -1479,7 +1485,7 @@ intel_hdmi_set_edid(struct drm_connector *connector, bool force)
 	return connected;
 }
 
-static enum drm_connector_status
+enum drm_connector_status
 intel_hdmi_detect(struct drm_connector *connector, bool force)
 {
 	enum drm_connector_status status;
diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
index dd50491..75b5028 100644
--- a/drivers/gpu/drm/i915/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/intel_lspcon.c
@@ -37,6 +37,12 @@ bool is_lspcon_active(struct intel_digital_port *dig_port)
 	return dig_port->lspcon.active;
 }
 
+enum drm_connector_status
+lspcon_ls_mode_detect(struct drm_connector *connector, bool force)
+{
+	return intel_hdmi_detect(connector, force);
+}
+
 enum drm_lspcon_mode lspcon_get_current_mode(struct intel_lspcon *lspcon)
 {
 	enum drm_lspcon_mode current_mode;
-- 
1.9.1