sensirion_common.h

/*
    Copyright (c) 2017, Sensirion AG
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:

 * * Redistributions of source code must retain the above copyright notice, this
     list of conditions and the following disclaimer.

 * * Redistributions in binary form must reproduce the above copyright notice,
     this list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.

 * * Neither the name of Sensirion AG nor the names of its
     contributors may be used to endorse or promote products derived from
     this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef SENSIRION_COMMON_H
#define SENSIRION_COMMON_H

#include "sensirion_configuration.h"

#ifdef __cplusplus
extern "C" {
#endif

#define STATUS_OK 0
#define STATUS_FAIL (-1)

#ifndef NULL
#define NULL ((void *)0)
#endif

#ifdef BIG_ENDIAN
#define be16_to_cpu(s) (s)
#define be32_to_cpu(s) (s)
#define be64_to_cpu(s) (s)
#else
#define be16_to_cpu(s) (((u16)(s) << 8) | (0xff & ((u16)(s)) >> 8))
#define be32_to_cpu(s) (((u32)be16_to_cpu(s) << 16) | \
                        (0xffff & (be16_to_cpu((s) >> 16))))
#define be64_to_cpu(s) (((u64)be32_to_cpu(s) << 32) | \
                        (0xffffffff & ((u64)be32_to_cpu((s) >> 32))))
#endif

#ifndef ARRAY_SIZE
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#endif

#define CRC8_POLYNOMIAL             0x31
#define CRC8_INIT                   0xFF
#define CRC8_LEN                    1

u8 sensirion_common_generate_crc(u8* data, u16 count);

s8 sensirion_common_check_crc(u8* data, u16 count, u8 checksum);

#ifdef __cplusplus
}
#endif

#endif /* SENSIRION_COMMON_H */