| /* |
| * Copyright (C) 2011 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 <stdint.h> |
| #include <sys/types.h> |
| |
| #include <utils/Errors.h> |
| |
| #include <fcntl.h> |
| #include <sys/ioctl.h> |
| #include <linux/fb.h> |
| |
| #include "DisplayHardware/VSyncBarrier.h" |
| |
| #ifndef FBIO_WAITFORVSYNC |
| #define FBIO_WAITFORVSYNC _IOW('F', 0x20, __u32) |
| #endif |
| |
| namespace android { |
| // --------------------------------------------------------------------------- |
| |
| VSyncBarrier::VSyncBarrier() : mFd(-EINVAL) { |
| #if HAS_WAITFORVSYNC |
| mFd = open("/dev/graphics/fb0", O_RDWR); |
| if (mFd < 0) { |
| mFd = -errno; |
| } |
| // try to see if FBIO_WAITFORVSYNC is supported |
| uint32_t crt = 0; |
| int err = ioctl(mFd, FBIO_WAITFORVSYNC, &crt); |
| if (err < 0) { |
| close(mFd); |
| mFd = -EINVAL; |
| } |
| #endif |
| } |
| |
| VSyncBarrier::~VSyncBarrier() { |
| if (mFd >= 0) { |
| close(mFd); |
| } |
| } |
| |
| status_t VSyncBarrier::initCheck() const { |
| return mFd < 0 ? mFd : status_t(NO_ERROR); |
| } |
| |
| // this must be thread-safe |
| status_t VSyncBarrier::wait(nsecs_t* timestamp) const { |
| if (mFd < 0) { |
| return mFd; |
| } |
| |
| int err; |
| uint32_t crt = 0; |
| do { |
| err = ioctl(mFd, FBIO_WAITFORVSYNC, &crt); |
| } while (err<0 && errno==EINTR); |
| if (err < 0) { |
| return -errno; |
| } |
| // ideally this would come from the driver |
| timestamp[0] = systemTime(); |
| return NO_ERROR; |
| } |
| |
| // --------------------------------------------------------------------------- |
| }; // namespace android |