1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index c15718b4862a..d3c4945a0e36 100644
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -1024,3 +1024,31 @@ err_out:
 	memunmap(base);
 	return err;
 }
+
+int
+intel_opregion_get_panel_type(struct drm_device *dev)
+{
+	u32 panel_details;
+	int ret;
+
+	ret = swsci(dev, SWSCI_GBDA_PANEL_DETAILS, 0x0, &panel_details);
+	if (ret) {
+		DRM_DEBUG_KMS("Failed to get panel details from OpRegion (%d)\n",
+			      ret);
+		return ret;
+	}
+
+	ret = (panel_details >> 8) & 0xff;
+	if (ret > 0x10) {
+		DRM_DEBUG_KMS("Invalid OpRegion panel type 0x%x\n", ret);
+		return -EINVAL;
+	}
+
+	/* fall back to VBT panel type? */
+	if (ret == 0x0) {
+		DRM_DEBUG_KMS("No panel type in OpRegion\n");
+		return -ENODEV;
+	}
+
+	return ret - 1;
+}