drm/i915: introduce intel_audio_codec_{enable, disable}

Introduce functions to enable/disable the audio codec, incorporating the
ELD setup within enable. The disable is initially limited to HSW,
covering exactly what was done previously.

The only functional difference is that ELD valid is no longer set if
there is no connector with ELD, which should be the right thing to do
anyway. Otherwise the sequence remains the same, with warts and all, in
preparation for applying more sanity.

v2: add kernel doc.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index 158ad60..f291efc 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -96,9 +96,9 @@
 	return true;
 }
 
-static void g4x_write_eld(struct drm_connector *connector,
-			  struct intel_encoder *encoder,
-			  struct drm_display_mode *mode)
+static void g4x_audio_codec_enable(struct drm_connector *connector,
+				   struct intel_encoder *encoder,
+				   struct drm_display_mode *mode)
 {
 	struct drm_i915_private *dev_priv = connector->dev->dev_private;
 	uint8_t *eld = connector->eld;
@@ -136,9 +136,22 @@
 	I915_WRITE(G4X_AUD_CNTL_ST, tmp);
 }
 
-static void haswell_write_eld(struct drm_connector *connector,
-			      struct intel_encoder *encoder,
-			      struct drm_display_mode *mode)
+static void hsw_audio_codec_disable(struct intel_encoder *encoder)
+{
+	struct drm_device *dev = encoder->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_crtc *crtc = encoder->base.crtc;
+	enum pipe pipe = to_intel_crtc(crtc)->pipe;
+	uint32_t tmp;
+
+	tmp = I915_READ(HSW_AUD_PIN_ELD_CP_VLD);
+	tmp &= ~((AUDIO_OUTPUT_ENABLE_A | AUDIO_ELD_VALID_A) << (pipe * 4));
+	I915_WRITE(HSW_AUD_PIN_ELD_CP_VLD, tmp);
+}
+
+static void hsw_audio_codec_enable(struct drm_connector *connector,
+				   struct intel_encoder *encoder,
+				   struct drm_display_mode *mode)
 {
 	struct drm_i915_private *dev_priv = connector->dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
@@ -211,11 +224,16 @@
 	tmp = I915_READ(aud_cntrl_st2);
 	tmp |= eldv;
 	I915_WRITE(aud_cntrl_st2, tmp);
+
+	/* XXX: Transitional */
+	tmp = I915_READ(HSW_AUD_PIN_ELD_CP_VLD);
+	tmp |= ((AUDIO_OUTPUT_ENABLE_A | AUDIO_ELD_VALID_A) << (pipe * 4));
+	I915_WRITE(HSW_AUD_PIN_ELD_CP_VLD, tmp);
 }
 
-static void ironlake_write_eld(struct drm_connector *connector,
-			       struct intel_encoder *encoder,
-			       struct drm_display_mode *mode)
+static void ilk_audio_codec_enable(struct drm_connector *connector,
+				   struct intel_encoder *encoder,
+				   struct drm_display_mode *mode)
 {
 	struct drm_i915_private *dev_priv = connector->dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
@@ -303,7 +321,14 @@
 	I915_WRITE(aud_cntrl_st2, tmp);
 }
 
-void intel_write_eld(struct intel_encoder *intel_encoder)
+/**
+ * intel_audio_codec_enable - Enable the audio codec for HD audio
+ * @intel_encoder: encoder on which to enable audio
+ *
+ * The enable sequences may only be performed after enabling the transcoder and
+ * port, and after completed link training.
+ */
+void intel_audio_codec_enable(struct intel_encoder *intel_encoder)
 {
 	struct drm_encoder *encoder = &intel_encoder->base;
 	struct intel_crtc *crtc = to_intel_crtc(encoder->crtc);
@@ -329,8 +354,24 @@
 
 	connector->eld[6] = drm_av_sync_delay(connector, mode) / 2;
 
-	if (dev_priv->display.write_eld)
-		dev_priv->display.write_eld(connector, intel_encoder, mode);
+	if (dev_priv->display.audio_codec_enable)
+		dev_priv->display.audio_codec_enable(connector, intel_encoder, mode);
+}
+
+/**
+ * intel_audio_codec_disable - Disable the audio codec for HD audio
+ * @encoder: encoder on which to disable audio
+ *
+ * The disable sequences must be performed before disabling the transcoder or
+ * port.
+ */
+void intel_audio_codec_disable(struct intel_encoder *encoder)
+{
+	struct drm_device *dev = encoder->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (dev_priv->display.audio_codec_disable)
+		dev_priv->display.audio_codec_disable(encoder);
 }
 
 /**
@@ -341,12 +382,14 @@
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	if (IS_G4X(dev))
-		dev_priv->display.write_eld = g4x_write_eld;
-	else if (IS_VALLEYVIEW(dev))
-		dev_priv->display.write_eld = ironlake_write_eld;
-	else if (IS_HASWELL(dev) || INTEL_INFO(dev)->gen >= 8)
-		dev_priv->display.write_eld = haswell_write_eld;
-	else if (HAS_PCH_SPLIT(dev))
-		dev_priv->display.write_eld = ironlake_write_eld;
+	if (IS_G4X(dev)) {
+		dev_priv->display.audio_codec_enable = g4x_audio_codec_enable;
+	} else if (IS_VALLEYVIEW(dev)) {
+		dev_priv->display.audio_codec_enable = ilk_audio_codec_enable;
+	} else if (IS_HASWELL(dev) || INTEL_INFO(dev)->gen >= 8) {
+		dev_priv->display.audio_codec_enable = hsw_audio_codec_enable;
+		dev_priv->display.audio_codec_disable = hsw_audio_codec_disable;
+	} else if (HAS_PCH_SPLIT(dev)) {
+		dev_priv->display.audio_codec_enable = ilk_audio_codec_enable;
+	}
 }