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open-gpu-kernel-modules/src/common/displayport/inc/dp_bitstream.h
Andy Ritger 1739a20efc 515.43.04
2022-05-09 13:18:59 -07:00

99 lines
3.4 KiB
C++

/*
* SPDX-FileCopyrightText: Copyright (c) 1993-2021 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/******************************* DisplayPort *******************************\
* *
* Module: dp_bitstream.h *
* This is an implementation of the big endian bit stream *
* *
\***************************************************************************/
#ifndef INCLUDED_DP_BITSTREAM_H
#define INCLUDED_DP_BITSTREAM_H
#include "dp_buffer.h"
namespace DisplayPort
{
//
// Bitstream reader interface
// - reads a packed stream of bits in Big Endian format
// - handles alignment, buffering, and buffer bounds checking
//
class BitStreamReader
{
Buffer * sourceBuffer;
unsigned bitsOffset;
unsigned bitsEnd;
public:
// Read 1-32 bits from the stream into *value. Returns true on success
bool read(unsigned * value, unsigned bits);
// Read 1-32 bits from stream. Returns 'default' on failure.
unsigned readOrDefault(unsigned bits, unsigned defaultValue);
// Skip bits until we're aligned to the power of two alignment
bool align(unsigned align);
unsigned offset();
Buffer * buffer();
BitStreamReader(Buffer * buffer, unsigned bitsOffset, unsigned bitsCount);
};
//
// Bitstream writer interface
//
class BitStreamWriter
{
Buffer * targetBuffer;
unsigned bitsOffset;
public:
//
// Create a bitstream writer at a specific bit offset
// into an already existing buffer
//
BitStreamWriter(Buffer * buffer, unsigned bitsOffset = 0);
//
// Write n bits to the buffer in big endian format.
// No buffering is performed.
//
bool write(unsigned value, unsigned bits);
//
// Emit zero's until the offset is divisible by align.
// CAVEAT: align must be a power of 2 (eg 8)
//
bool align(unsigned align);
//
// Get current offset and buffer target
//
unsigned offset();
Buffer * buffer();
};
}
#endif //INCLUDED_DP_BITSTREAM_H