drm/i915/display: move clk off sanitize to its own function

This allows us to isolate reading and writing to the
ICL_DPCLKA_CFGCR0 during the sanitize phase.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Clinton Taylor <Clinton.A.Taylor@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191217230529.25092-1-lucas.demarchi@intel.com

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

@@ -2999,11 +2999,40 @@ static void icl_unmap_plls_to_ports(struct intel_encoder *encoder)
 	mutex_unlock(&dev_priv->dpll_lock);
 }
 
+static void icl_sanitize_port_clk_off(struct drm_i915_private *dev_priv,
+				      u32 port_mask, bool ddi_clk_needed)
+{
+	enum port port;
+	u32 val;
+
+	val = I915_READ(ICL_DPCLKA_CFGCR0);
+	for_each_port_masked(port, port_mask) {
+		enum phy phy = intel_port_to_phy(dev_priv, port);
+
+		bool ddi_clk_ungated = !(val &
+					 icl_dpclka_cfgcr0_clk_off(dev_priv,
+								   phy));
+
+		if (ddi_clk_needed == ddi_clk_ungated)
+			continue;
+
+		/*
+		 * Punt on the case now where clock is gated, but it would
+		 * be needed by the port. Something else is really broken then.
+		 */
+		if (WARN_ON(ddi_clk_needed))
+			continue;
+
+		DRM_NOTE("PHY %c is disabled/in DSI mode with an ungated DDI clock, gate it\n",
+			 phy_name(port));
+		val |= icl_dpclka_cfgcr0_clk_off(dev_priv, phy);
+		I915_WRITE(ICL_DPCLKA_CFGCR0, val);
+	}
+}
+
 void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder)
 {
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
-	u32 val;
-	enum port port;
 	u32 port_mask;
 	bool ddi_clk_needed;
 
@@ -3052,29 +3081,7 @@ void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder)
 		ddi_clk_needed = false;
 	}
 
-	val = I915_READ(ICL_DPCLKA_CFGCR0);
-	for_each_port_masked(port, port_mask) {
-		enum phy phy = intel_port_to_phy(dev_priv, port);
-
-		bool ddi_clk_ungated = !(val &
-					 icl_dpclka_cfgcr0_clk_off(dev_priv,
-								   phy));
-
-		if (ddi_clk_needed == ddi_clk_ungated)
-			continue;
-
-		/*
-		 * Punt on the case now where clock is gated, but it would
-		 * be needed by the port. Something else is really broken then.
-		 */
-		if (WARN_ON(ddi_clk_needed))
-			continue;
-
-		DRM_NOTE("PHY %c is disabled/in DSI mode with an ungated DDI clock, gate it\n",
-			 phy_name(port));
-		val |= icl_dpclka_cfgcr0_clk_off(dev_priv, phy);
-		I915_WRITE(ICL_DPCLKA_CFGCR0, val);
-	}
+	icl_sanitize_port_clk_off(dev_priv, port_mask, ddi_clk_needed);
 }
 
 static void intel_ddi_clk_select(struct intel_encoder *encoder,