drm/i915/ICL: Add pre_pll_enable hook for ICL and set DFLEXDPMLE in this hook

In case of Legacy DP connector on TypeC port, the
flex IO DPMLE register is set to number of lanes configured
by the display driver which will be programmed into DDI_BUF_CTL
PORT_WIDTH_SELECTION.
This needs to be programmed before enabling the shared PLLs hence
add a pre_pll_enable hook for ICL and add this programming in that hook.

v2:
* Remove the check for combophy port (Jose)
* Simplify the port reversal check logic (Jose)

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Jose Roberto de Souza <jose.souza@intel.com>
Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181023191248.26418-2-manasi.d.navare@intel.com

drivers/gpu/drm/i915/intel_ddi.c

@@ -3311,6 +3311,53 @@ static void bxt_ddi_pre_pll_enable(struct intel_encoder *encoder,
 	bxt_ddi_phy_set_lane_optim_mask(encoder, mask);
 }
 
+static void intel_ddi_set_fia_lane_count(struct intel_encoder *encoder,
+					 const struct intel_crtc_state *pipe_config,
+					 enum port port)
+{
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
+	enum tc_port tc_port = intel_port_to_tc(dev_priv, port);
+	u32 val = I915_READ(PORT_TX_DFLEXDPMLE1);
+	bool lane_reversal = dig_port->saved_port_bits & DDI_BUF_PORT_REVERSAL;
+
+	val &= ~DFLEXDPMLE1_DPMLETC_MASK(tc_port);
+	switch (pipe_config->lane_count) {
+	case 1:
+		val |= (lane_reversal) ? DFLEXDPMLE1_DPMLETC_ML3(tc_port) :
+		DFLEXDPMLE1_DPMLETC_ML0(tc_port);
+		break;
+	case 2:
+		val |= (lane_reversal) ? DFLEXDPMLE1_DPMLETC_ML3_2(tc_port) :
+		DFLEXDPMLE1_DPMLETC_ML1_0(tc_port);
+		break;
+	case 4:
+		val |= DFLEXDPMLE1_DPMLETC_ML3_0(tc_port);
+		break;
+	default:
+		MISSING_CASE(pipe_config->lane_count);
+	}
+	I915_WRITE(PORT_TX_DFLEXDPMLE1, val);
+}
+
+static void icl_ddi_pre_pll_enable(struct intel_encoder *encoder,
+				   const struct intel_crtc_state *pipe_config,
+				   const struct drm_connector_state *conn_state)
+{
+	enum port port = encoder->port;
+	struct intel_digital_port *dig_port = enc_to_dig_port(&encoder->base);
+
+	/*
+	 * Program the lane count for static/dynamic connections on Type-C ports.
+	 * Skip this step for TBT.
+	 */
+	if (dig_port->tc_type == TC_PORT_UNKNOWN ||
+	    dig_port->tc_type == TC_PORT_TBT)
+		return;
+
+	intel_ddi_set_fia_lane_count(encoder, pipe_config, port);
+}
+
 void intel_ddi_prepare_link_retrain(struct intel_dp *intel_dp)
 {
 	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
@@ -3828,6 +3875,8 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 	intel_encoder->enable = intel_enable_ddi;
 	if (IS_GEN9_LP(dev_priv))
 		intel_encoder->pre_pll_enable = bxt_ddi_pre_pll_enable;
+	if (IS_ICELAKE(dev_priv))
+		intel_encoder->pre_pll_enable = icl_ddi_pre_pll_enable;
 	intel_encoder->pre_enable = intel_ddi_pre_enable;
 	intel_encoder->disable = intel_disable_ddi;
 	intel_encoder->post_disable = intel_ddi_post_disable;