drm/i915: Add {preemph,voltage}_max() vfuncs

Different platforms have different max vswing/preemph settings.
Turn that into a pair vfuncs so we can decouple intel_dp.c and
intel_ddi.c further.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200512174145.3186-5-ville.syrjala@linux.intel.comReviewed-by: Manasi Navare <manasi.d.navare@intel.com>

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -2109,10 +2109,10 @@ static void bxt_ddi_vswing_sequence(struct intel_encoder *encoder,
 				     ddi_translations[level].deemphasis);
 }
 
-u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder)
+static u8 intel_ddi_dp_voltage_max(struct intel_dp *intel_dp)
 {
+	struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
-	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 	enum port port = encoder->port;
 	enum phy phy = intel_port_to_phy(dev_priv, port);
 	int n_entries;
@@ -2165,19 +2165,9 @@ u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder)
  * used on all DDI platforms. Should that change we need to
  * rethink this code.
  */
-u8 intel_ddi_dp_pre_emphasis_max(struct intel_encoder *encoder, u8 voltage_swing)
+static u8 intel_ddi_dp_preemph_max(struct intel_dp *intel_dp)
 {
-	switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-	case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-		return DP_TRAIN_PRE_EMPH_LEVEL_3;
-	case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-		return DP_TRAIN_PRE_EMPH_LEVEL_2;
-	case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-		return DP_TRAIN_PRE_EMPH_LEVEL_1;
-	case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
-	default:
-		return DP_TRAIN_PRE_EMPH_LEVEL_0;
-	}
+	return DP_TRAIN_PRE_EMPH_LEVEL_3;
 }
 
 static void cnl_ddi_vswing_program(struct intel_encoder *encoder,
@@ -4535,6 +4525,9 @@ intel_ddi_init_dp_connector(struct intel_digital_port *intel_dig_port)
 	else
 		intel_dig_port->dp.set_signal_levels = hsw_set_signal_levels;
 
+	intel_dig_port->dp.voltage_max = intel_ddi_dp_voltage_max;
+	intel_dig_port->dp.preemph_max = intel_ddi_dp_preemph_max;
+
 	if (INTEL_GEN(dev_priv) < 12) {
 		intel_dig_port->dp.regs.dp_tp_ctl = DP_TP_CTL(port);
 		intel_dig_port->dp.regs.dp_tp_status = DP_TP_STATUS(port);

drivers/gpu/drm/i915/display/intel_ddi.h

@@ -42,9 +42,6 @@ void intel_ddi_compute_min_voltage_level(struct drm_i915_private *dev_priv,
 					 struct intel_crtc_state *crtc_state);
 u32 bxt_signal_levels(struct intel_dp *intel_dp);
 u32 ddi_signal_levels(struct intel_dp *intel_dp);
-u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder);
-u8 intel_ddi_dp_pre_emphasis_max(struct intel_encoder *encoder,
-				 u8 voltage_swing);
 int intel_ddi_toggle_hdcp_signalling(struct intel_encoder *intel_encoder,
 				     bool enable);
 void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder);

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -1367,6 +1367,9 @@ struct intel_dp {
 	void (*set_idle_link_train)(struct intel_dp *intel_dp);
 	void (*set_signal_levels)(struct intel_dp *intel_dp);
 
+	u8 (*preemph_max)(struct intel_dp *intel_dp);
+	u8 (*voltage_max)(struct intel_dp *intel_dp);
+
 	/* Displayport compliance testing */
 	struct intel_dp_compliance compliance;
 

drivers/gpu/drm/i915/display/intel_dp.c

@@ -3990,58 +3990,24 @@ intel_dp_get_link_status(struct intel_dp *intel_dp, u8 link_status[DP_LINK_STATU
 				DP_LINK_STATUS_SIZE) == DP_LINK_STATUS_SIZE;
 }
 
-/* These are source-specific values. */
-u8
-intel_dp_voltage_max(struct intel_dp *intel_dp)
+static u8 intel_dp_voltage_max_2(struct intel_dp *intel_dp)
 {
-	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
-	struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
-	enum port port = encoder->port;
+	return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
+}
 
-	if (HAS_DDI(dev_priv))
-		return intel_ddi_dp_voltage_max(encoder);
-	else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv) ||
-		 (HAS_PCH_SPLIT(dev_priv) && port != PORT_A))
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
-	else
-		return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
+static u8 intel_dp_voltage_max_3(struct intel_dp *intel_dp)
+{
+	return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
 }
 
-u8
-intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, u8 voltage_swing)
+static u8 intel_dp_pre_empemph_max_2(struct intel_dp *intel_dp)
 {
-	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
-	struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
-	enum port port = encoder->port;
+	return DP_TRAIN_PRE_EMPH_LEVEL_2;
+}
 
-	if (HAS_DDI(dev_priv)) {
-		return intel_ddi_dp_pre_emphasis_max(encoder, voltage_swing);
-	} else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv) ||
-		   (HAS_PCH_SPLIT(dev_priv) && port != PORT_A)) {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-			return DP_TRAIN_PRE_EMPH_LEVEL_3;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-			return DP_TRAIN_PRE_EMPH_LEVEL_1;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
-		default:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		}
-	} else {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
-			return DP_TRAIN_PRE_EMPH_LEVEL_2;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
-			return DP_TRAIN_PRE_EMPH_LEVEL_1;
-		case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
-		default:
-			return DP_TRAIN_PRE_EMPH_LEVEL_0;
-		}
-	}
+static u8 intel_dp_pre_empemph_max_3(struct intel_dp *intel_dp)
+{
+	return DP_TRAIN_PRE_EMPH_LEVEL_3;
 }
 
 static void vlv_set_signal_levels(struct intel_dp *intel_dp)
@@ -8355,6 +8321,15 @@ bool intel_dp_init(struct drm_i915_private *dev_priv,
 	else
 		intel_dig_port->dp.set_signal_levels = g4x_set_signal_levels;
 
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv) ||
+	    (HAS_PCH_SPLIT(dev_priv) && port != PORT_A)) {
+		intel_dig_port->dp.preemph_max = intel_dp_pre_empemph_max_3;
+		intel_dig_port->dp.voltage_max = intel_dp_voltage_max_3;
+	} else {
+		intel_dig_port->dp.preemph_max = intel_dp_pre_empemph_max_2;
+		intel_dig_port->dp.voltage_max = intel_dp_voltage_max_2;
+	}
+
 	intel_dig_port->dp.output_reg = output_reg;
 	intel_dig_port->max_lanes = 4;
 	intel_dig_port->dp.regs.dp_tp_ctl = DP_TP_CTL(port);

drivers/gpu/drm/i915/display/intel_dp.h

@@ -92,10 +92,6 @@ intel_dp_program_link_training_pattern(struct intel_dp *intel_dp,
 void
 intel_dp_set_signal_levels(struct intel_dp *intel_dp);
 void intel_dp_set_idle_link_train(struct intel_dp *intel_dp);
-u8
-intel_dp_voltage_max(struct intel_dp *intel_dp);
-u8
-intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, u8 voltage_swing);
 void intel_dp_compute_rate(struct intel_dp *intel_dp, int port_clock,
 			   u8 *link_bw, u8 *rate_select);
 bool intel_dp_source_supports_hbr2(struct intel_dp *intel_dp);

drivers/gpu/drm/i915/display/intel_dp_link_training.c

@@ -34,6 +34,21 @@ intel_dp_dump_link_status(const u8 link_status[DP_LINK_STATUS_SIZE])
 		      link_status[3], link_status[4], link_status[5]);
 }
 
+static u8 dp_pre_emphasis_max(u8 voltage_swing)
+{
+	switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
+	case DP_TRAIN_VOLTAGE_SWING_LEVEL_0:
+		return DP_TRAIN_PRE_EMPH_LEVEL_3;
+	case DP_TRAIN_VOLTAGE_SWING_LEVEL_1:
+		return DP_TRAIN_PRE_EMPH_LEVEL_2;
+	case DP_TRAIN_VOLTAGE_SWING_LEVEL_2:
+		return DP_TRAIN_PRE_EMPH_LEVEL_1;
+	case DP_TRAIN_VOLTAGE_SWING_LEVEL_3:
+	default:
+		return DP_TRAIN_PRE_EMPH_LEVEL_0;
+	}
+}
+
 void intel_dp_get_adjust_train(struct intel_dp *intel_dp,
 			       const u8 link_status[DP_LINK_STATUS_SIZE])
 {
@@ -53,11 +68,12 @@ void intel_dp_get_adjust_train(struct intel_dp *intel_dp,
 			p = this_p;
 	}
 
-	voltage_max = intel_dp_voltage_max(intel_dp);
+	voltage_max = intel_dp->voltage_max(intel_dp);
 	if (v >= voltage_max)
 		v = voltage_max | DP_TRAIN_MAX_SWING_REACHED;
 
-	preemph_max = intel_dp_pre_emphasis_max(intel_dp, v);
+	preemph_max = min(intel_dp->preemph_max(intel_dp),
+			  dp_pre_emphasis_max(v));
 	if (p >= preemph_max)
 		p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;