drm/i915/display: Add HAS_MBUS_JOINING

This will make easy to extend MBUS joining support to future platforms
that also supports this feature.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220331184152.1086943-1-jose.souza@intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -1364,6 +1364,8 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
 #define HAS_D12_PLANE_MINIMIZATION(dev_priv) (IS_ROCKETLAKE(dev_priv) || \
 					      IS_ALDERLAKE_S(dev_priv))
 
+#define HAS_MBUS_JOINING(i915) (IS_ALDERLAKE_P(i915))
+
 /* i915_gem.c */
 void i915_gem_init_early(struct drm_i915_private *dev_priv);
 void i915_gem_cleanup_early(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_pm.c

@@ -6038,7 +6038,7 @@ skl_compute_ddb(struct intel_atomic_state *state)
 			return ret;
 	}
 
-	if (IS_ALDERLAKE_P(dev_priv))
+	if (HAS_MBUS_JOINING(dev_priv))
 		new_dbuf_state->joined_mbus =
 			adlp_check_mbus_joined(new_dbuf_state->active_pipes);
 
@@ -6530,7 +6530,7 @@ void skl_wm_get_hw_state(struct drm_i915_private *dev_priv)
 		to_intel_dbuf_state(dev_priv->dbuf.obj.state);
 	struct intel_crtc *crtc;
 
-	if (IS_ALDERLAKE_P(dev_priv))
+	if (HAS_MBUS_JOINING(dev_priv))
 		dbuf_state->joined_mbus = intel_de_read(dev_priv, MBUS_CTL) & MBUS_JOIN;
 
 	for_each_intel_crtc(&dev_priv->drm, crtc) {
@@ -8192,7 +8192,7 @@ static void update_mbus_pre_enable(struct intel_atomic_state *state)
 	const struct intel_dbuf_state *dbuf_state =
 		intel_atomic_get_new_dbuf_state(state);
 
-	if (!IS_ALDERLAKE_P(dev_priv))
+	if (!HAS_MBUS_JOINING(dev_priv))
 		return;
 
 	/*