drm/i915/gen9bc: Handle TGP PCH during suspend/resume

For Legacy S3 suspend/resume GEN9 BC needs to enable and
setup TGP PCH.

v2:
* Move Wa_14010685332 into it's own function - vsyrjala
* Add TODO comment about figuring out if we can move this workaround - imre
v3:
* Rename cnp_irq_post_reset() to cnp_display_clock_wa()
* Add TODO item mentioning we need to clarify which platforms this
  workaround applies to
* Just use ibx_irq_reset() in gen8_irq_reset(). This code should be
  functionally equivalent on gen9 bc to the code v2 added
* Drop icp_hpd_irq_setup() call in spt_hpd_irq_setup(), this looks to be
  more or less identical to spt_hpd_irq_setup() minus additionally enabling
  one port. Will update i915 to use icp_hpd_irq_setup() for ICP in a
  separate patch.
v4:
* Revert Wa_14010685332 system list in comments to how it was before
* Add back HAS_PCH_SPLIT() check before calling ibx_irq_reset()

Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay@intel.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210217180016.1937401-1-lyude@redhat.com

drivers/gpu/drm/i915/i915_irq.c

@@ -3040,6 +3040,24 @@ static void valleyview_irq_reset(struct drm_i915_private *dev_priv)
 	spin_unlock_irq(&dev_priv->irq_lock);
 }
 
+static void cnp_display_clock_wa(struct drm_i915_private *dev_priv)
+{
+	struct intel_uncore *uncore = &dev_priv->uncore;
+
+	/*
+	 * Wa_14010685332:cnp/cmp,tgp,adp
+	 * TODO: Clarify which platforms this applies to
+	 * TODO: Figure out if this workaround can be applied in the s0ix suspend/resume handlers as
+	 * on earlier platforms and whether the workaround is also needed for runtime suspend/resume
+	 */
+	if (INTEL_PCH_TYPE(dev_priv) == PCH_CNP ||
+	    (INTEL_PCH_TYPE(dev_priv) >= PCH_TGP && INTEL_PCH_TYPE(dev_priv) < PCH_DG1)) {
+		intel_uncore_rmw(uncore, SOUTH_CHICKEN1, SBCLK_RUN_REFCLK_DIS,
+				 SBCLK_RUN_REFCLK_DIS);
+		intel_uncore_rmw(uncore, SOUTH_CHICKEN1, SBCLK_RUN_REFCLK_DIS, 0);
+	}
+}
+
 static void gen8_irq_reset(struct drm_i915_private *dev_priv)
 {
 	struct intel_uncore *uncore = &dev_priv->uncore;
@@ -3063,6 +3081,8 @@ static void gen8_irq_reset(struct drm_i915_private *dev_priv)
 
 	if (HAS_PCH_SPLIT(dev_priv))
 		ibx_irq_reset(dev_priv);
+
+	cnp_display_clock_wa(dev_priv);
 }
 
 static void gen11_display_irq_reset(struct drm_i915_private *dev_priv)
@@ -3104,15 +3124,7 @@ static void gen11_display_irq_reset(struct drm_i915_private *dev_priv)
 	if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
 		GEN3_IRQ_RESET(uncore, SDE);
 
-	/* Wa_14010685332:cnp/cmp,tgp,adp */
-	if (INTEL_PCH_TYPE(dev_priv) == PCH_CNP ||
-	    (INTEL_PCH_TYPE(dev_priv) >= PCH_TGP &&
-	     INTEL_PCH_TYPE(dev_priv) < PCH_DG1)) {
-		intel_uncore_rmw(uncore, SOUTH_CHICKEN1,
-				 SBCLK_RUN_REFCLK_DIS, SBCLK_RUN_REFCLK_DIS);
-		intel_uncore_rmw(uncore, SOUTH_CHICKEN1,
-				 SBCLK_RUN_REFCLK_DIS, 0);
-	}
+	cnp_display_clock_wa(dev_priv);
 }
 
 static void gen11_irq_reset(struct drm_i915_private *dev_priv)
@@ -3764,9 +3776,19 @@ static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
 	}
 }
 
+static void icp_irq_postinstall(struct drm_i915_private *dev_priv)
+{
+	struct intel_uncore *uncore = &dev_priv->uncore;
+	u32 mask = SDE_GMBUS_ICP;
+
+	GEN3_IRQ_INIT(uncore, SDE, ~mask, 0xffffffff);
+}
+
 static void gen8_irq_postinstall(struct drm_i915_private *dev_priv)
 {
-	if (HAS_PCH_SPLIT(dev_priv))
+	if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
+		icp_irq_postinstall(dev_priv);
+	else if (HAS_PCH_SPLIT(dev_priv))
 		ibx_irq_postinstall(dev_priv);
 
 	gen8_gt_irq_postinstall(&dev_priv->gt);
@@ -3775,13 +3797,6 @@ static void gen8_irq_postinstall(struct drm_i915_private *dev_priv)
 	gen8_master_intr_enable(dev_priv->uncore.regs);
 }
 
-static void icp_irq_postinstall(struct drm_i915_private *dev_priv)
-{
-	struct intel_uncore *uncore = &dev_priv->uncore;
-	u32 mask = SDE_GMBUS_ICP;
-
-	GEN3_IRQ_INIT(uncore, SDE, ~mask, 0xffffffff);
-}
 
 static void gen11_irq_postinstall(struct drm_i915_private *dev_priv)
 {