mirror of https://github.com/ARMmbed/mbed-os.git
247 lines
10 KiB
C
247 lines
10 KiB
C
/** \addtogroup hal */
|
|
/** @{*/
|
|
/* mbed Microcontroller Library
|
|
* Copyright (c) 2018 ARM Limited
|
|
* 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.
|
|
*/
|
|
#ifndef MBED_CRC_HAL_API_H
|
|
#define MBED_CRC_HAL_API_H
|
|
|
|
#include <stdbool.h>
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
/** CRC Polynomial value
|
|
*
|
|
* Different polynomial values supported
|
|
*/
|
|
typedef enum crc_polynomial {
|
|
POLY_OTHER = 0,
|
|
POLY_8BIT_CCITT = 0x07, // x8+x2+x+1
|
|
POLY_7BIT_SD = 0x9, // x7+x3+1;
|
|
POLY_16BIT_CCITT = 0x1021, // x16+x12+x5+1
|
|
POLY_16BIT_IBM = 0x8005, // x16+x15+x2+1
|
|
POLY_32BIT_ANSI = 0x04C11DB7, // x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
|
|
POLY_32BIT_REV_ANSI = 0xEDB88320
|
|
} crc_polynomial_t;
|
|
|
|
typedef struct crc_mbed_config {
|
|
/** CRC Polynomial. Example polynomial: 0x21 = 0010_0011 = x^5+x+1 */
|
|
uint32_t polynomial;
|
|
/** CRC Bit Width */
|
|
uint32_t width;
|
|
/** Initial seed value for the computation. */
|
|
uint32_t initial_xor;
|
|
/** Final xor value for the computation. */
|
|
uint32_t final_xor;
|
|
/** Reflect bits on input. */
|
|
bool reflect_in;
|
|
/** Reflect bits in final result before returning. */
|
|
bool reflect_out;
|
|
} crc_mbed_config_t;
|
|
|
|
#if DEVICE_CRC
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* \defgroup hal_crc Hardware CRC
|
|
*
|
|
* The Hardware CRC HAL API provides a low-level interface to the Hardware CRC
|
|
* module of a target platform.
|
|
*
|
|
* # Defined behaviour
|
|
*
|
|
* * Function hal_crc_is_supported() returns true if platform supports hardware
|
|
* CRC for the given polynomial/width - verified by test ::crc_is_supported_test.
|
|
* * Function hal_crc_is_supported() returns false if platform does not support hardware
|
|
* CRC for the given polynomial/width - verified by test ::crc_is_supported_test.
|
|
* * Function hal_crc_is_supported() returns false if given pointer to configuration
|
|
* structure is undefined (NULL) - verified by test ::crc_is_supported_invalid_param_test.
|
|
* * If CRC module does not support one of the following settings: initial_xor, final_xor
|
|
* reflect_in, reflect_out, then these operations should be handled by the driver
|
|
* - Verified by test ::crc_calc_single_test.
|
|
* * Platform which supports hardware CRC must be able to handle at least one of the predefined
|
|
* polynomial/width configurations that can be constructed in the MbedCRC class: POLY_8BIT_CCITT,
|
|
* POLY_7BIT_SD, POLY_16BIT_CCITT, POLY_16BIT_IBM, POLY_32BIT_ANSI
|
|
* - verified by test ::crc_is_supported_test, ::crc_calc_single_test.
|
|
* * Function hal_crc_compute_partial_start() configures CRC module with the given configuration
|
|
* - Verified by test ::crc_calc_single_test.
|
|
* * Calling hal_crc_compute_partial_start() without finalising the
|
|
* CRC calculation overrides the current configuration - Verified by test ::crc_reconfigure_test.
|
|
* * Function hal_crc_compute_partial() writes data to the CRC module - verified by test ::crc_calc_single_test.
|
|
* * Function hal_crc_compute_partial() can be call multiple times in succession in order to
|
|
* provide additional data to CRC module - verified by test ::crc_calc_multi_test.
|
|
* * Function hal_crc_compute_partial() does nothing if pointer to buffer is undefined or
|
|
* data length is equal to 0 - verified by test ::crc_compute_partial_invalid_param_test.
|
|
* * Function hal_crc_get_result() returns the checksum result from the CRC module
|
|
* - verified by tests ::crc_calc_single_test, ::crc_calc_multi_test, ::crc_reconfigure_test.
|
|
*
|
|
* # Undefined behaviour
|
|
*
|
|
* * Calling hal_crc_compute_partial_start() function with invalid (unsupported) polynomial.
|
|
* * Calling hal_crc_compute_partial() or hal_crc_get_result() functions before hal_crc_compute_partial_start().
|
|
* * Calling hal_crc_get_result() function multiple times.
|
|
*
|
|
* # Non-functional requirements
|
|
*
|
|
* * CRC configuration provides the following settings:
|
|
* * polynomial - CRC Polynomial,
|
|
* * width - CRC bit width,
|
|
* * initial_xor - seed value for the computation,
|
|
* * final_xor - final xor value for the computation,
|
|
* * reflect_in - reflect bits on input,
|
|
* * reflect_out - reflect bits in final result before returning.
|
|
*
|
|
* # Potential bugs
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \defgroup hal_crc_tests crc hal tests
|
|
* The crc HAL tests ensure driver conformance to defined behaviour.
|
|
*
|
|
* To run the crc hal tests use the command:
|
|
*
|
|
* mbed test -t <toolchain> -m <target> -n tests-mbed_hal-crc*
|
|
*
|
|
*/
|
|
|
|
/** Determine if the current platform supports hardware CRC for given polynomial
|
|
*
|
|
* The purpose of this function is to inform the CRC Platform API whether the
|
|
* current platform has a hardware CRC module and that it can support the
|
|
* requested polynomial.
|
|
*
|
|
* Supported polynomials are restricted to the named polynomials that can be
|
|
* constructed in the MbedCRC class, POLY_8BIT_CCITT, POLY_7BIT_SD,
|
|
* POLY_16BIT_CCITT, POLY_16BIT_IBM and POLY_32BIT_ANSI.
|
|
*
|
|
* The current platform must support the given polynomials default parameters
|
|
* in order to return a true response. These include: reflect in, reflect out,
|
|
* initial xor and final xor. For example, POLY_32BIT_ANSI requires an initial
|
|
* and final xor of 0xFFFFFFFF, and reflection of both input and output. If any
|
|
* of these settings cannot be configured, the polynomial is not supported.
|
|
*
|
|
* This function is thread safe; it safe to call from multiple contexts if
|
|
* required.
|
|
*
|
|
* \param config Contains CRC configuration parameters for initializing the
|
|
* hardware CRC module. For example, polynomial and initial seed
|
|
* values.
|
|
*
|
|
* \return True if running if the polynomial is supported, false if not.
|
|
*/
|
|
bool hal_crc_is_supported(const crc_mbed_config_t *config);
|
|
|
|
/** Initialize the hardware CRC module with the given polynomial
|
|
*
|
|
* After calling this function, the CRC HAL module is ready to receive data
|
|
* using the hal_crc_compute_partial() function. The CRC module on the board
|
|
* is configured internally with the specified configuration and is ready
|
|
* to receive data.
|
|
*
|
|
* The platform configures itself based on the default configuration
|
|
* parameters of the input polynomial.
|
|
*
|
|
* This function must be called before calling hal_crc_compute_partial().
|
|
*
|
|
* This function must be called with a valid polynomial supported by the
|
|
* platform. The polynomial must be checked for support using the
|
|
* hal_crc_is_supported() function.
|
|
*
|
|
* Calling hal_crc_compute_partial_start() multiple times without finalizing the
|
|
* CRC calculation with hal_crc_get_result() overrides the current
|
|
* configuration and state, and the intermediate result of the computation is
|
|
* lost.
|
|
*
|
|
* This function is not thread safe. A CRC calculation must not be started from
|
|
* two different threads or contexts at the same time; calling this function
|
|
* from two different contexts may lead to configurations being overwritten and
|
|
* results being lost.
|
|
*
|
|
* \param config Contains CRC configuration parameters for initializing the
|
|
* hardware CRC module. For example, polynomial and initial seed
|
|
* values.
|
|
*/
|
|
void hal_crc_compute_partial_start(const crc_mbed_config_t *config);
|
|
|
|
/** Writes data to the current CRC module.
|
|
*
|
|
* Writes input data buffer bytes to the CRC data register. The CRC module
|
|
* must interpret the data as an array of bytes.
|
|
*
|
|
* The final transformations are not applied to the data; the CRC module must
|
|
* retain the intermediate result so that additional calls to this function
|
|
* can be made, appending the additional data to the calculation.
|
|
*
|
|
* To obtain the final result of the CRC calculation, hal_crc_get_result() is
|
|
* called to apply the final transformations to the data.
|
|
*
|
|
* If the function is passed an undefined pointer, or the size of the buffer is
|
|
* specified to be 0, this function does nothing and returns.
|
|
*
|
|
* This function can be called multiple times in succession. This can be used
|
|
* to calculate the CRC result of streamed data.
|
|
*
|
|
* This function is not thread safe. There is only one instance of the CRC
|
|
* module active at a time. Calling this function from multiple contexts
|
|
* appends different data to the same, single instance of the module, which causes an
|
|
* erroneous value to be calculated.
|
|
*
|
|
* \param data Input data stream to be written into the CRC calculation
|
|
* \param size Size of the data stream in bytes
|
|
*/
|
|
void hal_crc_compute_partial(const uint8_t *data, const size_t size);
|
|
|
|
/* Reads the checksum result from the CRC module.
|
|
*
|
|
* Reads the final checksum result for the final checksum value. The returned
|
|
* value is cast as an unsigned 32-bit integer. The actual size of the returned
|
|
* result depends on the polynomial used to configure the CRC module.
|
|
*
|
|
* Additional transformations that are used in the default configuration of the
|
|
* input polynomial are applied to the result before it is returned from this
|
|
* function. These transformations include: the final xor being appended to the
|
|
* calculation, and the result being reflected if required.
|
|
*
|
|
* Calling this function multiple times is undefined. The first call to this
|
|
* function returns the final result of the CRC calculation. The return
|
|
* value on successive calls is undefined because the contents of the register after
|
|
* accessing them is platform-specific.
|
|
*
|
|
* This function is not thread safe. There is only one instance of the CRC
|
|
* module active at a time. Calling this function from multiple contexts may
|
|
* return incorrect data or affect the current state of the module.
|
|
*
|
|
* \return The final CRC checksum after the reflections and final calculations
|
|
* have been applied.
|
|
*/
|
|
uint32_t hal_crc_get_result(void);
|
|
|
|
/**@}*/
|
|
|
|
#ifdef __cplusplus
|
|
};
|
|
#endif
|
|
|
|
#endif // DEVICE_CRC
|
|
#endif // MBED_CRC_HAL_API_H
|
|
|
|
/**@}*/
|