drm/i915/icl: Find DSI presence for ICL

This patch detects DSI presence for ICL platform
by reading VBT. DSI detection is done while initializing
DSI using newly added function intel_gen11_dsi_init.

v2 by Jani:
 - Preserve old behavour of intel_bios_is_dsi_present()
 - s/intel_gen11_dsi_init/icl_dsi_init/g
Signed-off-by: Madhav Chauhan <madhav.chauhan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/2324cdfc8918bda3165354e5e0d15053b1074f14.1540900289.git.jani.nikula@intel.com

drivers/gpu/drm/i915/icl_dsi.c

@@ -971,3 +971,11 @@ static void __attribute__((unused)) gen11_dsi_disable(
 	/* step4: disable IO power */
 	gen11_dsi_disable_io_power(encoder);
 }
+
+void icl_dsi_init(struct drm_i915_private *dev_priv)
+{
+	enum port port;
+
+	if (!intel_bios_is_dsi_present(dev_priv, &port))
+		return;
+}

drivers/gpu/drm/i915/intel_bios.c

@@ -2039,17 +2039,17 @@ bool intel_bios_is_dsi_present(struct drm_i915_private *dev_priv,
 
 		dvo_port = child->dvo_port;
 
-		switch (dvo_port) {
-		case DVO_PORT_MIPIA:
-		case DVO_PORT_MIPIC:
+		if (dvo_port == DVO_PORT_MIPIA ||
+		    (dvo_port == DVO_PORT_MIPIB && IS_ICELAKE(dev_priv)) ||
+		    (dvo_port == DVO_PORT_MIPIC && !IS_ICELAKE(dev_priv))) {
 			if (port)
 				*port = dvo_port - DVO_PORT_MIPIA;
 			return true;
-		case DVO_PORT_MIPIB:
-		case DVO_PORT_MIPID:
+		} else if (dvo_port == DVO_PORT_MIPIB ||
+			   dvo_port == DVO_PORT_MIPIC ||
+			   dvo_port == DVO_PORT_MIPID) {
 			DRM_DEBUG_KMS("VBT has unsupported DSI port %c\n",
 				      port_name(dvo_port - DVO_PORT_MIPIA));
-			break;
 		}
 	}
 

drivers/gpu/drm/i915/intel_display.c

@@ -14128,6 +14128,7 @@ static void intel_setup_outputs(struct drm_i915_private *dev_priv)
 		intel_ddi_init(dev_priv, PORT_D);
 		intel_ddi_init(dev_priv, PORT_E);
 		intel_ddi_init(dev_priv, PORT_F);
+		icl_dsi_init(dev_priv);
 	} else if (IS_GEN9_LP(dev_priv)) {
 		/*
 		 * FIXME: Broxton doesn't support port detection via the

drivers/gpu/drm/i915/intel_drv.h

@@ -1860,6 +1860,9 @@ void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
 /* vlv_dsi.c */
 void vlv_dsi_init(struct drm_i915_private *dev_priv);
 
+/* icl_dsi.c */
+void icl_dsi_init(struct drm_i915_private *dev_priv);
+
 /* intel_dsi_dcs_backlight.c */
 int intel_dsi_dcs_init_backlight_funcs(struct intel_connector *intel_connector);