drm_hwcomposer: refactor platform directory

Motivation:

Platform term meaning used in drm_hwcomposer does not correspond to the
content of the platform directory. Platform directory consists of:
1. Buffer information getters for different gralloc (currently called platform).
2. Composition planner logic (which has flaws and should be reworked into
   layer->plane mapping during validation stage logic).
3. DrmGenericImpoter with reference counting logic.

Android-11 IMapper@4 metadata API offers a generic way to access buffer
information which makes other gralloc buffer information getters obsolete.
Legacy getters should be maintained for some time until all known users
will migrate to Mapper@4 API.

Implementation:

1. Split 'PlatformImporter' logic to 'Importer' only and 'Buffer Getter' logic.
   a. Remove buffer_handle_t parameter from ImportBuffer(). Instead user should
      get BufferInfo using ConvertBoInfo to struct hwc_drm_bo_t, then use it for
      ImportBuffer().
   b. Move DrmGenericImporter.{cpp/h} into the drm directory.

2. Isolate planner code in single file and move it to compositor directory as
   compositor/Planner.{cpp/h}

3. Rename platform definition
   a. Rename platform directory to bufferinfo.
   b. Rename/move bufferinfo/platorm*.{cpp,h} getters to
      bufferinfo/legacy/BufferInfo*.{cpp,h}. Align class names/includes.

4. Split legacy/metadata getters logic.
   a. Apply existing bufferinfogetter base class only for legacy getters.
   b. Combine legacy/generic gettera under new base class.
   c. Create a placeholder for generic(metadata) getter.

Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
diff --git a/bufferinfo/BufferInfoGetter.cpp b/bufferinfo/BufferInfoGetter.cpp
new file mode 100644
index 0000000..8b3f1a4
--- /dev/null
+++ b/bufferinfo/BufferInfoGetter.cpp
@@ -0,0 +1,136 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "hwc-buffer-info-getter"
+
+#include "BufferInfoGetter.h"
+
+#if PLATFORM_SDK_VERSION >= 30
+#include "BufferInfoMapperMetadata.h"
+#endif
+
+#include <cutils/properties.h>
+#include <gralloc_handle.h>
+#include <hardware/gralloc.h>
+#include <log/log.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+namespace android {
+
+BufferInfoGetter *BufferInfoGetter::GetInstance() {
+  static std::unique_ptr<BufferInfoGetter> inst;
+  if (inst == nullptr) {
+#if PLATFORM_SDK_VERSION >= 30
+    inst.reset(BufferInfoMapperMetadata::CreateInstance());
+    if (inst == nullptr) {
+      ALOGW(
+          "Generic buffer getter is not available. Falling back to legacy...");
+#endif
+      inst.reset(LegacyBufferInfoGetter::CreateInstance());
+#if PLATFORM_SDK_VERSION >= 30
+    }
+#endif
+  }
+
+  return inst.get();
+}
+
+bool BufferInfoGetter::IsHandleUsable(buffer_handle_t handle) {
+  hwc_drm_bo_t bo;
+  memset(&bo, 0, sizeof(hwc_drm_bo_t));
+
+  if (ConvertBoInfo(handle, &bo) != 0)
+    return false;
+
+  if (bo.prime_fds[0] == 0)
+    return false;
+
+  return true;
+}
+
+int LegacyBufferInfoGetter::Init() {
+  int ret = hw_get_module(GRALLOC_HARDWARE_MODULE_ID,
+                          (const hw_module_t **)&gralloc_);
+  if (ret) {
+    ALOGE("Failed to open gralloc module");
+    return ret;
+  }
+
+  ALOGI("Using %s gralloc module: %s\n", gralloc_->common.name,
+        gralloc_->common.author);
+
+  return 0;
+}
+
+uint32_t LegacyBufferInfoGetter::ConvertHalFormatToDrm(uint32_t hal_format) {
+  switch (hal_format) {
+    case HAL_PIXEL_FORMAT_RGB_888:
+      return DRM_FORMAT_BGR888;
+    case HAL_PIXEL_FORMAT_BGRA_8888:
+      return DRM_FORMAT_ARGB8888;
+    case HAL_PIXEL_FORMAT_RGBX_8888:
+      return DRM_FORMAT_XBGR8888;
+    case HAL_PIXEL_FORMAT_RGBA_8888:
+      return DRM_FORMAT_ABGR8888;
+    case HAL_PIXEL_FORMAT_RGB_565:
+      return DRM_FORMAT_BGR565;
+    case HAL_PIXEL_FORMAT_YV12:
+      return DRM_FORMAT_YVU420;
+    default:
+      ALOGE("Cannot convert hal format to drm format %u", hal_format);
+      return DRM_FORMAT_INVALID;
+  }
+}
+
+uint32_t BufferInfoGetter::DrmFormatToBitsPerPixel(uint32_t drm_format) {
+  switch (drm_format) {
+    case DRM_FORMAT_ARGB8888:
+    case DRM_FORMAT_XBGR8888:
+    case DRM_FORMAT_ABGR8888:
+      return 32;
+    case DRM_FORMAT_BGR888:
+      return 24;
+    case DRM_FORMAT_BGR565:
+      return 16;
+    case DRM_FORMAT_YVU420:
+      return 12;
+    default:
+      ALOGE("Cannot convert hal format %u to bpp (returning 32)", drm_format);
+      return 32;
+  }
+}
+
+bool BufferInfoGetter::IsDrmFormatRgb(uint32_t drm_format) {
+  switch (drm_format) {
+    case DRM_FORMAT_ARGB8888:
+    case DRM_FORMAT_XBGR8888:
+    case DRM_FORMAT_ABGR8888:
+    case DRM_FORMAT_BGR888:
+    case DRM_FORMAT_BGR565:
+      return true;
+    default:
+      return false;
+  }
+}
+
+__attribute__((weak)) LegacyBufferInfoGetter *
+LegacyBufferInfoGetter::CreateInstance() {
+  ALOGE("No legacy buffer info getters available");
+  return nullptr;
+}
+
+}  // namespace android