mbed-os/targets/TARGET_Cypress/TARGET_PSOC6/crc_api.c

101 lines
2.5 KiB
C

/* mbed Microcontroller Library
* Copyright (c) 2019 Cypress Semiconductor Corporation
* SPDX-License-Identifier: Apache-2.0
*
* 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 "device.h"
#if DEVICE_CRC
#include "mbed_assert.h"
#include "crc_api.h"
#include "psoc6_utils.h"
#include "cy_crypto_core_crc.h"
static uint32_t crcWidth = 0;
static uint32_t crcShift = 0;
static uint32_t crcXorMask;
/* Cypress CRYPTO HW supports ANY CRC algorithms from CRC-3 to CRC-32 */
bool hal_crc_is_supported(const crc_mbed_config_t *config)
{
return (config != NULL);
}
void hal_crc_compute_partial_start(const crc_mbed_config_t *config)
{
uint32_t myMask = 0;
if (!hal_crc_is_supported(config) || (cy_reserve_crypto(CY_CRYPTO_CRC_HW) != 0))
{
return;
}
crcWidth = config->width;
crcShift = (uint32_t)(!config->reflect_out) * (crcWidth & 7u);
if (crcShift) {
crcShift = 8u - crcShift;
for (uint32_t i = 0; i < crcShift; i++) {
myMask |= 1 << i;
}
crcXorMask = config->final_xor & myMask;
}
Cy_Crypto_Core_Crc_CalcInit(CRYPTO, config->width,
config->polynomial,
config->reflect_in,
0,
config->reflect_out,
config->final_xor >> crcShift,
config->initial_xor);
}
void hal_crc_compute_partial(const uint8_t *data, const size_t size)
{
if ((data == NULL) || (size <= 0) || (crcWidth == 0)) {
return;
}
Cy_Crypto_Core_Crc_CalcPartial(CRYPTO, data, size);
}
uint32_t hal_crc_get_result(void)
{
uint32_t result = 0;
if (crcWidth == 0) {
return 0xffffffffu;
}
Cy_Crypto_Core_Crc_CalcFinish(CRYPTO, crcWidth, &result);
if (crcShift) {
result = result << crcShift;
result = result ^ crcXorMask;
}
crcWidth = 0;
cy_free_crypto(CY_CRYPTO_CRC_HW);
return result;
}
#endif //DEVICE_CRC