drm/amdgpu: To define whether the GPU has DCE engine.

For virtual display feature, when the GPU has DCE engine, need to disable
the VGA render and CRTC, or it will hang when initialize GMC. So first detect
whether the GPU has DCE engine.
Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c

@@ -259,6 +259,33 @@ static const int object_connector_convert[] = {
 	DRM_MODE_CONNECTOR_Unknown
 };
 
+bool amdgpu_atombios_has_dce_engine_info(struct amdgpu_device *adev)
+{
+	struct amdgpu_mode_info *mode_info = &adev->mode_info;
+	struct atom_context *ctx = mode_info->atom_context;
+	int index = GetIndexIntoMasterTable(DATA, Object_Header);
+	u16 size, data_offset;
+	u8 frev, crev;
+	ATOM_DISPLAY_OBJECT_PATH_TABLE *path_obj;
+	ATOM_OBJECT_HEADER *obj_header;
+
+	if (!amdgpu_atom_parse_data_header(ctx, index, &size, &frev, &crev, &data_offset))
+		return false;
+
+	if (crev < 2)
+		return false;
+
+	obj_header = (ATOM_OBJECT_HEADER *) (ctx->bios + data_offset);
+	path_obj = (ATOM_DISPLAY_OBJECT_PATH_TABLE *)
+	    (ctx->bios + data_offset +
+	     le16_to_cpu(obj_header->usDisplayPathTableOffset));
+
+	if (path_obj->ucNumOfDispPath)
+		return true;
+	else
+		return false;
+}
+
 bool amdgpu_atombios_get_connector_info_from_object_table(struct amdgpu_device *adev)
 {
 	struct amdgpu_mode_info *mode_info = &adev->mode_info;

drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.h

@@ -140,6 +140,8 @@ struct amdgpu_i2c_bus_rec amdgpu_atombios_lookup_i2c_gpio(struct amdgpu_device *
 							  uint8_t id);
 void amdgpu_atombios_i2c_init(struct amdgpu_device *adev);
 
+bool amdgpu_atombios_has_dce_engine_info(struct amdgpu_device *adev);
+
 bool amdgpu_atombios_get_connector_info_from_object_table(struct amdgpu_device *adev);
 
 int amdgpu_atombios_get_clock_info(struct amdgpu_device *adev);