--- /dev/null
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "backendclient.h"
+#include "backendmanager.h"
+#include "drmhwctwo.h"
+
+namespace android {
+
+HWC2::Error BackendClient::ValidateDisplay(DrmHwcTwo::HwcDisplay *display,
+ uint32_t *num_types,
+ uint32_t * /*num_requests*/) {
+ for (auto & [ layer_handle, layer ] : display->layers()) {
+ layer.set_validated_type(HWC2::Composition::Client);
+ ++*num_types;
+ }
+ return HWC2::Error::HasChanges;
+}
+
+REGISTER_BACKEND("client", BackendClient);
+
+} // namespace android
--- /dev/null
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_BACKEND_CLIENT_H
+#define ANDROID_BACKEND_CLIENT_H
+
+#include "backend.h"
+#include "drmhwctwo.h"
+
+namespace android {
+
+class BackendClient : public Backend {
+ public:
+ HWC2::Error ValidateDisplay(DrmHwcTwo::HwcDisplay *display,
+ uint32_t *num_types,
+ uint32_t *num_requests) override;
+};
+} // namespace android
+
+#endif