drm/i915: Reorganize .disable hooks for pre-DDI DP

Most of our DP encoder hooks are split into per-platform variants.
.disable() an exception, and thus it's a bit messy. Let's split it
up as well. We'll leave the common parts in a helper called by
each platform specific hook. Now each platform has mostly its own
hooks. Some hooks are still shared between vlv and chv, and between
g4x and ilk. None of the remaining shared hooks have any platform
checks in them however so duplicating them doesn't seem particularly
useful.

There is a subtle change on VLV/CHV where we now disable PSR before
audio, whereas before we disabled PSR after audio. That should be
totally fine, and PSR is disabled by default anyway. Jani also pointed
out to me that PSR + audio doesn't seem like a particularly realistic
combination.

v2: Drop the PSR HAS_DDI check here (Rodrigo)
    Pimp up the commit message a bit based on a chat with Jani

Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170920151251.5961-1-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/intel_dp.c

@@ -2692,24 +2692,46 @@ static void intel_disable_dp(struct intel_encoder *encoder,
 			     const struct drm_connector_state *old_conn_state)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
-	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 
 	if (old_crtc_state->has_audio)
 		intel_audio_codec_disable(encoder);
 
-	if (!HAS_DDI(dev_priv))
-		intel_psr_disable(intel_dp, old_crtc_state);
-
 	/* Make sure the panel is off before trying to change the mode. But also
 	 * ensure that we have vdd while we switch off the panel. */
 	intel_edp_panel_vdd_on(intel_dp);
 	intel_edp_backlight_off(old_conn_state);
 	intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
 	intel_edp_panel_off(intel_dp);
+}
+
+static void g4x_disable_dp(struct intel_encoder *encoder,
+			   const struct intel_crtc_state *old_crtc_state,
+			   const struct drm_connector_state *old_conn_state)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
+
+	intel_disable_dp(encoder, old_crtc_state, old_conn_state);
 
 	/* disable the port before the pipe on g4x */
-	if (INTEL_GEN(dev_priv) < 5)
-		intel_dp_link_down(intel_dp);
+	intel_dp_link_down(intel_dp);
+}
+
+static void ilk_disable_dp(struct intel_encoder *encoder,
+			   const struct intel_crtc_state *old_crtc_state,
+			   const struct drm_connector_state *old_conn_state)
+{
+	intel_disable_dp(encoder, old_crtc_state, old_conn_state);
+}
+
+static void vlv_disable_dp(struct intel_encoder *encoder,
+			   const struct intel_crtc_state *old_crtc_state,
+			   const struct drm_connector_state *old_conn_state)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
+
+	intel_psr_disable(intel_dp, old_crtc_state);
+
+	intel_disable_dp(encoder, old_crtc_state, old_conn_state);
 }
 
 static void ilk_post_disable_dp(struct intel_encoder *encoder,
@@ -6145,7 +6167,6 @@ bool intel_dp_init(struct drm_i915_private *dev_priv,
 		goto err_encoder_init;
 
 	intel_encoder->compute_config = intel_dp_compute_config;
-	intel_encoder->disable = intel_disable_dp;
 	intel_encoder->get_hw_state = intel_dp_get_hw_state;
 	intel_encoder->get_config = intel_dp_get_config;
 	intel_encoder->suspend = intel_dp_encoder_suspend;
@@ -6153,18 +6174,24 @@ bool intel_dp_init(struct drm_i915_private *dev_priv,
 		intel_encoder->pre_pll_enable = chv_dp_pre_pll_enable;
 		intel_encoder->pre_enable = chv_pre_enable_dp;
 		intel_encoder->enable = vlv_enable_dp;
+		intel_encoder->disable = vlv_disable_dp;
 		intel_encoder->post_disable = chv_post_disable_dp;
 		intel_encoder->post_pll_disable = chv_dp_post_pll_disable;
 	} else if (IS_VALLEYVIEW(dev_priv)) {
 		intel_encoder->pre_pll_enable = vlv_dp_pre_pll_enable;
 		intel_encoder->pre_enable = vlv_pre_enable_dp;
 		intel_encoder->enable = vlv_enable_dp;
+		intel_encoder->disable = vlv_disable_dp;
 		intel_encoder->post_disable = vlv_post_disable_dp;
+	} else if (INTEL_GEN(dev_priv) >= 5) {
+		intel_encoder->pre_enable = g4x_pre_enable_dp;
+		intel_encoder->enable = g4x_enable_dp;
+		intel_encoder->disable = ilk_disable_dp;
+		intel_encoder->post_disable = ilk_post_disable_dp;
 	} else {
 		intel_encoder->pre_enable = g4x_pre_enable_dp;
 		intel_encoder->enable = g4x_enable_dp;
-		if (INTEL_GEN(dev_priv) >= 5)
-			intel_encoder->post_disable = ilk_post_disable_dp;
+		intel_encoder->disable = g4x_disable_dp;
 	}
 
 	intel_dig_port->port = port;