drm_hwcomposer: Add backend-dependent validation for HwcDisplay class
Different DRM/KMS backends have a variable set of limitations, which is
not always exposed via DRM ioctls.
This implementation of backend-dependent validation provides a register
of platform-specific inherited backend class to the map by BackendManager
class. ValidateDisplay function is moved to generic backend
implementantion and separated into 2 additional methods.
The map key is a string that contains the corresponding DRM driver name.
During DrmHwcTwo class initialization the vendor.hwc.backend_override
system property and driver name will be checked and a backend will be set
for the appropriate display. If the map does not have any backend for the
named driver, the generic backend will be used.
Signed-off-by: Matvii Zorin <matvii.zorin@globallogic.com>
diff --git a/include/backendmanager.h b/include/backendmanager.h
new file mode 100644
index 0000000..d141652
--- /dev/null
+++ b/include/backendmanager.h
@@ -0,0 +1,58 @@
+/*
+ * 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_MANAGER_H
+#define ANDROID_BACKEND_MANAGER_H
+
+#include "backend.h"
+#include "drmhwctwo.h"
+
+#include <functional>
+#include <map>
+#include <string>
+#include <vector>
+
+#define REGISTER_BACKEND(name_str_, backend_) \
+ static int \
+ backend = BackendManager::GetInstance() \
+ .RegisterBackend(name_str_, \
+ []() -> std::unique_ptr<Backend> { \
+ return std::make_unique<backend_>(); \
+ });
+
+namespace android {
+
+class BackendManager {
+ public:
+ using backend_constructor_t = std::function<std::unique_ptr<Backend>()>;
+ static BackendManager &GetInstance();
+ int RegisterBackend(const std::string &name,
+ backend_constructor_t backend_constructor);
+ int SetBackendForDisplay(DrmHwcTwo::HwcDisplay *display);
+ std::unique_ptr<Backend> GetBackendByName(std::string &name);
+ HWC2::Error ValidateDisplay(DrmHwcTwo::HwcDisplay *display,
+ uint32_t *num_types, uint32_t *num_requests);
+
+ private:
+ BackendManager() = default;
+
+ static const std::vector<std::string> client_devices_;
+
+ std::map<std::string, backend_constructor_t> available_backends_;
+};
+} // namespace android
+
+#endif