mirror of
https://github.com/zephyrproject-rtos/zephyr
synced 2025-09-15 03:21:57 +00:00
44782fd8af
Use `do { ... } while (false)' instead of `do { ... } while (0)'.
Use comparisons with zero instead of implicitly testing integers.
Use comparisons with NULL instead of implicitly testing pointers.
Use comparisons with NUL instead of implicitly testing plain chars.
Use `bool' instead of `int' to represent Boolean values.
Use `while (true)' instead of `while (1)' to express infinite loops.
Signed-off-by: frei tycho <tfrei@baumer.com>
57 lines
1.1 KiB
C
57 lines
1.1 KiB
C
/*
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* Copyright (c) 2020 Intel Corporation
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* Copyright (c) 2017 Nordic Semiconductor ASA
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* Copyright (c) 2015 Runtime Inc
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <zephyr/sys/crc.h>
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static const uint8_t crc8_ccitt_small_table[16] = {
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0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
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0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d
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};
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uint8_t crc8_ccitt(uint8_t val, const void *buf, size_t cnt)
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{
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size_t i;
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const uint8_t *p = buf;
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for (i = 0; i < cnt; i++) {
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val ^= p[i];
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val = (val << 4) ^ crc8_ccitt_small_table[val >> 4];
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val = (val << 4) ^ crc8_ccitt_small_table[val >> 4];
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}
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return val;
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}
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uint8_t crc8(const uint8_t *src, size_t len, uint8_t polynomial, uint8_t initial_value,
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bool reversed)
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{
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uint8_t crc = initial_value;
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size_t i, j;
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for (i = 0; i < len; i++) {
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crc ^= src[i];
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for (j = 0; j < 8; j++) {
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if (reversed) {
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if ((crc & 0x01) != 0) {
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crc = (crc >> 1) ^ polynomial;
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} else {
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crc >>= 1;
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}
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} else {
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if ((crc & 0x80) != 0) {
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crc = (crc << 1) ^ polynomial;
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} else {
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crc <<= 1;
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}
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}
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}
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}
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return crc;
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}
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