1 files changed, 95 insertions, 0 deletions
diff --git a/drm/UEventListener.cpp b/drm/UEventListener.cpp
new file mode 100644
index 0000000..eae0608
--- /dev/null
+++ b/drm/UEventListener.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2016 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-uevent-listener"
+
+#include "UEventListener.h"
+
+#include <linux/netlink.h>
+#include <sys/socket.h>
+#include <xf86drm.h>
+
+#include <cassert>
+#include <cerrno>
+#include <cstring>
+
+#include "utils/log.h"
+
+/* Originally defined in system/core/libsystem/include/system/graphics.h */
+#define HAL_PRIORITY_URGENT_DISPLAY (-8)
+
+namespace android {
+
+UEventListener::UEventListener()
+    : Worker("uevent-listener", HAL_PRIORITY_URGENT_DISPLAY){};
+
+int UEventListener::Init() {
+  uevent_fd_ = UniqueFd(
+      socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT));
+  if (!uevent_fd_) {
+    ALOGE("Failed to open uevent socket: %s", strerror(errno));
+    return -errno;
+  }
+
+  struct sockaddr_nl addr {};
+  addr.nl_family = AF_NETLINK;
+  addr.nl_pid = 0;
+  addr.nl_groups = 0xFFFFFFFF;
+
+  int ret = bind(uevent_fd_.Get(), (struct sockaddr *)&addr, sizeof(addr));
+  if (ret) {
+    ALOGE("Failed to bind uevent socket: %s", strerror(errno));
+    return -errno;
+  }
+
+  return InitWorker();
+}
+
+void UEventListener::Routine() {
+  char buffer[1024];
+  ssize_t ret = 0;
+
+  while (true) {
+    ret = read(uevent_fd_.Get(), &buffer, sizeof(buffer));
+    if (ret == 0)
+      return;
+
+    if (ret < 0) {
+      ALOGE("Got error reading uevent %zd", ret);
+      return;
+    }
+
+    if (!hotplug_handler_)
+      continue;
+
+    bool drm_event = false;
+    bool hotplug_event = false;
+    for (uint32_t i = 0; i < ret;) {
+      char *event = buffer + i;
+      if (strcmp(event, "DEVTYPE=drm_minor") != 0)
+        drm_event = true;
+      else if (strcmp(event, "HOTPLUG=1") != 0)
+        hotplug_event = true;
+
+      i += strlen(event) + 1;
+    }
+
+    if (drm_event && hotplug_event && hotplug_handler_) {
+      hotplug_handler_();
+    }
+  }
+}
+}  // namespace android