drm/i915: Split g4x+ HDMI audio presence detect from port enable

Follow the hsw+ approach toggle the audio presence detect
when we set up the ELD, instead of doing it when turning the
port on/off.

This will facilitate audio enable/disable to happen during
fastsets instead of requiring a full modeset.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231121054324.9988-8-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/display/g4x_hdmi.c

@@ -228,8 +228,6 @@ static void g4x_hdmi_enable_port(struct intel_encoder *encoder,
 	temp = intel_de_read(dev_priv, intel_hdmi->hdmi_reg);
 
 	temp |= SDVO_ENABLE;
-	if (pipe_config->has_audio)
-		temp |= HDMI_AUDIO_ENABLE;
 
 	intel_de_write(dev_priv, intel_hdmi->hdmi_reg, temp);
 	intel_de_posting_read(dev_priv, intel_hdmi->hdmi_reg);
@@ -240,12 +238,16 @@ static void g4x_hdmi_audio_enable(struct intel_encoder *encoder,
 				  const struct drm_connector_state *conn_state)
 {
 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+	struct intel_hdmi *hdmi = enc_to_intel_hdmi(encoder);
 
 	if (!crtc_state->has_audio)
 		return;
 
 	drm_WARN_ON(&i915->drm, !crtc_state->has_hdmi_sink);
 
+	/* Enable audio presence detect */
+	intel_de_rmw(i915, hdmi->hdmi_reg, 0, HDMI_AUDIO_ENABLE);
+
 	intel_audio_codec_enable(encoder, crtc_state, conn_state);
 }
 
@@ -253,10 +255,16 @@ static void g4x_hdmi_audio_disable(struct intel_encoder *encoder,
 				   const struct intel_crtc_state *old_crtc_state,
 				   const struct drm_connector_state *old_conn_state)
 {
+	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+	struct intel_hdmi *hdmi = enc_to_intel_hdmi(encoder);
+
 	if (!old_crtc_state->has_audio)
 		return;
 
 	intel_audio_codec_disable(encoder, old_crtc_state, old_conn_state);
+
+	/* Disable audio presence detect */
+	intel_de_rmw(i915, hdmi->hdmi_reg, HDMI_AUDIO_ENABLE, 0);
 }
 
 static void g4x_enable_hdmi(struct intel_atomic_state *state,
@@ -282,8 +290,6 @@ static void ibx_enable_hdmi(struct intel_atomic_state *state,
 	temp = intel_de_read(dev_priv, intel_hdmi->hdmi_reg);
 
 	temp |= SDVO_ENABLE;
-	if (pipe_config->has_audio)
-		temp |= HDMI_AUDIO_ENABLE;
 
 	/*
 	 * HW workaround, need to write this twice for issue
@@ -335,8 +341,6 @@ static void cpt_enable_hdmi(struct intel_atomic_state *state,
 	temp = intel_de_read(dev_priv, intel_hdmi->hdmi_reg);
 
 	temp |= SDVO_ENABLE;
-	if (pipe_config->has_audio)
-		temp |= HDMI_AUDIO_ENABLE;
 
 	/*
 	 * WaEnableHDMI8bpcBefore12bpc:snb,ivb
@@ -396,7 +400,7 @@ static void intel_disable_hdmi(struct intel_atomic_state *state,
 
 	temp = intel_de_read(dev_priv, intel_hdmi->hdmi_reg);
 
-	temp &= ~(SDVO_ENABLE | HDMI_AUDIO_ENABLE);
+	temp &= ~SDVO_ENABLE;
 	intel_de_write(dev_priv, intel_hdmi->hdmi_reg, temp);
 	intel_de_posting_read(dev_priv, intel_hdmi->hdmi_reg);