drm/i915: Introduce .set_idle_link_train() vfunc

Relocate a bunch of DDI specific code from intel_dp.c to intel_ddi.c
by introducing a .set_idle_link_train() vfunc.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200420200610.31798-3-ville.syrjala@linux.intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>

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

@@ -4018,6 +4018,34 @@ static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
 	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
 }
 
+static void intel_ddi_set_idle_link_train(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);
+	enum port port = encoder->port;
+	u32 val;
+
+	val = intel_de_read(dev_priv, intel_dp->regs.dp_tp_ctl);
+	val &= ~DP_TP_CTL_LINK_TRAIN_MASK;
+	val |= DP_TP_CTL_LINK_TRAIN_IDLE;
+	intel_de_write(dev_priv, intel_dp->regs.dp_tp_ctl, val);
+
+	/*
+	 * Until TGL on PORT_A we can have only eDP in SST mode. There the only
+	 * reason we need to set idle transmission mode is to work around a HW
+	 * issue where we enable the pipe while not in idle link-training mode.
+	 * In this case there is requirement to wait for a minimum number of
+	 * idle patterns to be sent.
+	 */
+	if (port == PORT_A && INTEL_GEN(dev_priv) < 12)
+		return;
+
+	if (intel_de_wait_for_set(dev_priv, intel_dp->regs.dp_tp_status,
+				  DP_TP_STATUS_IDLE_DONE, 1))
+		drm_err(&dev_priv->drm,
+			"Timed out waiting for DP idle patterns\n");
+}
+
 static bool intel_ddi_is_audio_enabled(struct drm_i915_private *dev_priv,
 				       enum transcoder cpu_transcoder)
 {
@@ -4463,6 +4491,7 @@ intel_ddi_init_dp_connector(struct intel_digital_port *intel_dig_port)
 	intel_dig_port->dp.prepare_link_retrain =
 		intel_ddi_prepare_link_retrain;
 	intel_dig_port->dp.set_link_train = intel_ddi_set_link_train;
+	intel_dig_port->dp.set_idle_link_train = intel_ddi_set_idle_link_train;
 
 	if (INTEL_GEN(dev_priv) >= 12)
 		intel_dig_port->dp.set_signal_levels = tgl_set_signal_levels;

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

@@ -1368,6 +1368,7 @@ struct intel_dp {
 	/* This is called before a link training is starterd */
 	void (*prepare_link_retrain)(struct intel_dp *intel_dp);
 	void (*set_link_train)(struct intel_dp *intel_dp, u8 dp_train_pat);
+	void (*set_idle_link_train)(struct intel_dp *intel_dp);
 	void (*set_signal_levels)(struct intel_dp *intel_dp);
 
 	/* Displayport compliance testing */

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

@@ -4365,33 +4365,8 @@ intel_dp_program_link_training_pattern(struct intel_dp *intel_dp,
 
 void intel_dp_set_idle_link_train(struct intel_dp *intel_dp)
 {
-	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
+	if (intel_dp->set_idle_link_train)
-	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+		intel_dp->set_idle_link_train(intel_dp);
-	enum port port = intel_dig_port->base.port;
-	u32 val;
-
-	if (!HAS_DDI(dev_priv))
-		return;
-
-	val = intel_de_read(dev_priv, intel_dp->regs.dp_tp_ctl);
-	val &= ~DP_TP_CTL_LINK_TRAIN_MASK;
-	val |= DP_TP_CTL_LINK_TRAIN_IDLE;
-	intel_de_write(dev_priv, intel_dp->regs.dp_tp_ctl, val);
-
-	/*
-	 * Until TGL on PORT_A we can have only eDP in SST mode. There the only
-	 * reason we need to set idle transmission mode is to work around a HW
-	 * issue where we enable the pipe while not in idle link-training mode.
-	 * In this case there is requirement to wait for a minimum number of
-	 * idle patterns to be sent.
-	 */
-	if (port == PORT_A && INTEL_GEN(dev_priv) < 12)
-		return;
-
-	if (intel_de_wait_for_set(dev_priv, intel_dp->regs.dp_tp_status,
-				  DP_TP_STATUS_IDLE_DONE, 1))
-		drm_err(&dev_priv->drm,
-			"Timed out waiting for DP idle patterns\n");
 }
 
 static void