1 files changed, 175 insertions, 0 deletions
diff --git a/drm/VSyncWorker.cpp b/drm/VSyncWorker.cpp
new file mode 100644
index 0000000..b2f7e5f
--- /dev/null
+++ b/drm/VSyncWorker.cpp
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2015 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-vsync-worker"
+
+#include "VSyncWorker.h"
+
+#include <log/log.h>
+#include <stdlib.h>
+#include <time.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+namespace android {
+
+VSyncWorker::VSyncWorker()
+    : Worker("vsync", HAL_PRIORITY_URGENT_DISPLAY),
+      drm_(NULL),
+      display_(-1),
+      enabled_(false),
+      last_timestamp_(-1) {
+}
+
+VSyncWorker::~VSyncWorker() {
+}
+
+int VSyncWorker::Init(DrmDevice *drm, int display) {
+  drm_ = drm;
+  display_ = display;
+
+  return InitWorker();
+}
+
+void VSyncWorker::RegisterCallback(std::shared_ptr<VsyncCallback> callback) {
+  Lock();
+  callback_ = callback;
+  Unlock();
+}
+
+void VSyncWorker::RegisterClientCallback(hwc2_callback_data_t data,
+                                         hwc2_function_pointer_t hook) {
+  Lock();
+  vsync_callback_data_ = data;
+  vsync_callback_hook_ = reinterpret_cast<HWC2_PFN_VSYNC>(hook);
+  Unlock();
+}
+
+void VSyncWorker::VSyncControl(bool enabled) {
+  Lock();
+  enabled_ = enabled;
+  last_timestamp_ = -1;
+  Unlock();
+
+  Signal();
+}
+
+/*
+ * Returns the timestamp of the next vsync in phase with last_timestamp_.
+ * For example:
+ *  last_timestamp_ = 137
+ *  frame_ns = 50
+ *  current = 683
+ *
+ *  ret = (50 * ((683 - 137)/50 + 1)) + 137
+ *  ret = 687
+ *
+ *  Thus, we must sleep until timestamp 687 to maintain phase with the last
+ *  timestamp.
+ */
+int64_t VSyncWorker::GetPhasedVSync(int64_t frame_ns, int64_t current) {
+  if (last_timestamp_ < 0)
+    return current + frame_ns;
+
+  return frame_ns * ((current - last_timestamp_) / frame_ns + 1) +
+         last_timestamp_;
+}
+
+static const int64_t kOneSecondNs = 1 * 1000 * 1000 * 1000;
+
+int VSyncWorker::SyntheticWaitVBlank(int64_t *timestamp) {
+  struct timespec vsync;
+  int ret = clock_gettime(CLOCK_MONOTONIC, &vsync);
+
+  float refresh = 60.0f;  // Default to 60Hz refresh rate
+  DrmConnector *conn = drm_->GetConnectorForDisplay(display_);
+  if (conn && conn->active_mode().v_refresh() != 0.0f)
+    refresh = conn->active_mode().v_refresh();
+  else
+    ALOGW("Vsync worker active with conn=%p refresh=%f\n", conn,
+          conn ? conn->active_mode().v_refresh() : 0.0f);
+
+  int64_t phased_timestamp = GetPhasedVSync(kOneSecondNs / refresh,
+                                            vsync.tv_sec * kOneSecondNs +
+                                                vsync.tv_nsec);
+  vsync.tv_sec = phased_timestamp / kOneSecondNs;
+  vsync.tv_nsec = phased_timestamp - (vsync.tv_sec * kOneSecondNs);
+  do {
+    ret = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &vsync, NULL);
+  } while (ret == -1 && errno == EINTR);
+  if (ret)
+    return ret;
+
+  *timestamp = (int64_t)vsync.tv_sec * kOneSecondNs + (int64_t)vsync.tv_nsec;
+  return 0;
+}
+
+void VSyncWorker::Routine() {
+  int ret;
+
+  Lock();
+  if (!enabled_) {
+    ret = WaitForSignalOrExitLocked();
+    if (ret == -EINTR) {
+      Unlock();
+      return;
+    }
+  }
+
+  int display = display_;
+  std::shared_ptr<VsyncCallback> callback(callback_);
+  Unlock();
+
+  DrmCrtc *crtc = drm_->GetCrtcForDisplay(display);
+  if (!crtc) {
+    ALOGE("Failed to get crtc for display");
+    return;
+  }
+  uint32_t high_crtc = (crtc->pipe() << DRM_VBLANK_HIGH_CRTC_SHIFT);
+
+  drmVBlank vblank;
+  memset(&vblank, 0, sizeof(vblank));
+  vblank.request.type = (drmVBlankSeqType)(
+      DRM_VBLANK_RELATIVE | (high_crtc & DRM_VBLANK_HIGH_CRTC_MASK));
+  vblank.request.sequence = 1;
+
+  int64_t timestamp;
+  ret = drmWaitVBlank(drm_->fd(), &vblank);
+  if (ret == -EINTR) {
+    return;
+  } else if (ret) {
+    ret = SyntheticWaitVBlank(&timestamp);
+    if (ret)
+      return;
+  } else {
+    timestamp = (int64_t)vblank.reply.tval_sec * kOneSecondNs +
+                (int64_t)vblank.reply.tval_usec * 1000;
+  }
+
+  if (!enabled_)
+    return;
+
+  if (callback)
+    callback->Callback(display, timestamp);
+
+  Lock();
+  if (enabled_ && vsync_callback_hook_ && vsync_callback_data_)
+    vsync_callback_hook_(vsync_callback_data_, display, timestamp);
+  Unlock();
+
+  last_timestamp_ = timestamp;
+}
+}  // namespace android