drm/i915/lnl: Fix check for TC phy

With MTL adding PICA between the port and the real phy, the path
add for DG2 stopped being followed and newer platforms are simply using
the older path for TC phys. LNL is no different than MTL in this aspect,
so just add it to the mess. In future the phy and port designation and
deciding if it's TC should better be cleaned up.

To make it just a bit better, also change intel_phy_is_snps() to show
this is DG2-only.
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231026184045.1015655-3-lucas.demarchi@intel.com

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

@@ -1784,31 +1784,31 @@ bool intel_phy_is_combo(struct drm_i915_private *dev_priv, enum phy phy)
 
 bool intel_phy_is_tc(struct drm_i915_private *dev_priv, enum phy phy)
 {
+	/*
+	 * DG2's "TC1", although TC-capable output, doesn't share the same flow
+	 * as other platforms on the display engine side and rather rely on the
+	 * SNPS PHY, that is programmed separately
+	 */
 	if (IS_DG2(dev_priv))
-		/* DG2's "TC1" output uses a SNPS PHY */
 		return false;
-	else if (IS_ALDERLAKE_P(dev_priv) || DISPLAY_VER_FULL(dev_priv) == IP_VER(14, 0))
+
+	if (DISPLAY_VER(dev_priv) >= 13)
 		return phy >= PHY_F && phy <= PHY_I;
 	else if (IS_TIGERLAKE(dev_priv))
 		return phy >= PHY_D && phy <= PHY_I;
 	else if (IS_ICELAKE(dev_priv))
 		return phy >= PHY_C && phy <= PHY_F;
-	else
-		return false;
+
+	return false;
 }
 
 bool intel_phy_is_snps(struct drm_i915_private *dev_priv, enum phy phy)
 {
-	if (phy == PHY_NONE)
-		return false;
-	else if (IS_DG2(dev_priv))
-		/*
-		 * All four "combo" ports and the TC1 port (PHY E) use
-		 * Synopsis PHYs.
-		 */
-		return phy <= PHY_E;
-
-	return false;
+	/*
+	 * For DG2, and for DG2 only, all four "combo" ports and the TC1 port
+	 * (PHY E) use Synopsis PHYs. See intel_phy_is_tc().
+	 */
+	return IS_DG2(dev_priv) && phy > PHY_NONE && phy <= PHY_E;
 }
 
 enum phy intel_port_to_phy(struct drm_i915_private *i915, enum port port)