drm/i915/bios: use port info child pointer to determine HPD invert

Avoid iterating the child devices.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/841c226efa424701161dd9f1793e0cf96b45a07c.1559308269.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_bios.c

@@ -2169,49 +2169,22 @@ bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv,
 
 /**
  * intel_bios_is_port_hpd_inverted - is HPD inverted for %port
- * @dev_priv:	i915 device instance
+ * @i915:	i915 device instance
  * @port:	port to check
  *
  * Return true if HPD should be inverted for %port.
  */
 bool
-intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
+intel_bios_is_port_hpd_inverted(const struct drm_i915_private *i915,
 				enum port port)
 {
-	const struct child_device_config *child;
-	int i;
+	const struct child_device_config *child =
+		i915->vbt.ddi_port_info[port].child;
 
-	if (WARN_ON_ONCE(!IS_GEN9_LP(dev_priv)))
+	if (WARN_ON_ONCE(!IS_GEN9_LP(i915)))
 		return false;
 
-	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
-		child = dev_priv->vbt.child_dev + i;
-
-		if (!child->hpd_invert)
-			continue;
-
-		switch (child->dvo_port) {
-		case DVO_PORT_DPA:
-		case DVO_PORT_HDMIA:
-			if (port == PORT_A)
-				return true;
-			break;
-		case DVO_PORT_DPB:
-		case DVO_PORT_HDMIB:
-			if (port == PORT_B)
-				return true;
-			break;
-		case DVO_PORT_DPC:
-		case DVO_PORT_HDMIC:
-			if (port == PORT_C)
-				return true;
-			break;
-		default:
-			break;
-		}
-	}
-
-	return false;
+	return child && child->hpd_invert;
 }
 
 /**

drivers/gpu/drm/i915/intel_bios.h

@@ -235,7 +235,7 @@ bool intel_bios_is_port_present(struct drm_i915_private *dev_priv, enum port por
 bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port);
 bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum port port);
 bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv, enum port *port);
-bool intel_bios_is_port_hpd_inverted(struct drm_i915_private *dev_priv,
+bool intel_bios_is_port_hpd_inverted(const struct drm_i915_private *i915,
 				     enum port port);
 bool intel_bios_is_lspcon_present(struct drm_i915_private *dev_priv,
 				  enum port port);