drm/i915: parse child device from VBT

On some laptops there is no HDMI/DP. But the xrandr still reports
several disconnected HDMI/display ports. In such case the user will be
confused.
 >DVI1 disconnected (normal left inverted right x axis y axis)
 >DP1 disconnected (normal left inverted right x axis y axis)
 >DVI2 disconnected (normal left inverted right x axis y axis)
 >DP2 disconnected (normal left inverted right x axis y axis)
 >DP3 disconnected (normal left inverted right x axis y axis)

This patch set is to use the child device parsed in VBT to decide whether
the HDMI/DP/LVDS/TV should be initialized.

Parse the child device from VBT.

The device class type is also added for LFP, TV, HDMI, DP output.

https://bugs.freedesktop.org/show_bug.cgi?id=22785

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
index 0f8e5f6..425ac9d 100644
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -549,4 +549,21 @@
 #define   SWF14_APM_STANDBY	0x1
 #define   SWF14_APM_RESTORE	0x0
 
+/* Add the device class for LFP, TV, HDMI */
+#define	 DEVICE_TYPE_INT_LFP	0x1022
+#define	 DEVICE_TYPE_INT_TV	0x1009
+#define	 DEVICE_TYPE_HDMI	0x60D2
+#define	 DEVICE_TYPE_DP		0x68C6
+#define	 DEVICE_TYPE_eDP	0x78C6
+
+/* define the DVO port for HDMI output type */
+#define		DVO_B		1
+#define		DVO_C		2
+#define		DVO_D		3
+
+/* define the PORT for DP output type */
+#define		PORT_IDPB	7
+#define		PORT_IDPC	8
+#define		PORT_IDPD	9
+
 #endif /* _I830_BIOS_H_ */