Kev Mann / mbed-dev-OS5_10_4

RTC auf true

hal/crc_api.h@2:7aab896b1a3b, 2019-03-13 (annotated)

Committer:
kevman
Date:
Wed Mar 13 11:03:24 2019 +0000
Revision:
2:7aab896b1a3b
Parent:
0:38ceb79fef03 
2019-03-13

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kevman 0:38ceb79fef03 1 /** \addtogroup hal */
kevman 0:38ceb79fef03 2 /** @{*/
kevman 0:38ceb79fef03 3 /* mbed Microcontroller Library
kevman 0:38ceb79fef03 4 * Copyright (c) 2018 ARM Limited
kevman 0:38ceb79fef03 5 *
kevman 0:38ceb79fef03 6 * Licensed under the Apache License, Version 2.0 (the "License");
kevman 0:38ceb79fef03 7 * you may not use this file except in compliance with the License.
kevman 0:38ceb79fef03 8 * You may obtain a copy of the License at
kevman 0:38ceb79fef03 9 *
kevman 0:38ceb79fef03 10 * http://www.apache.org/licenses/LICENSE-2.0
kevman 0:38ceb79fef03 11 *
kevman 0:38ceb79fef03 12 * Unless required by applicable law or agreed to in writing, software
kevman 0:38ceb79fef03 13 * distributed under the License is distributed on an "AS IS" BASIS,
kevman 0:38ceb79fef03 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kevman 0:38ceb79fef03 15 * See the License for the specific language governing permissions and
kevman 0:38ceb79fef03 16 * limitations under the License.
kevman 0:38ceb79fef03 17 */
kevman 0:38ceb79fef03 18 #ifndef MBED_CRC_HAL_API_H
kevman 0:38ceb79fef03 19 #define MBED_CRC_HAL_API_H
kevman 0:38ceb79fef03 20
kevman 0:38ceb79fef03 21 #include <stdbool.h>
kevman 0:38ceb79fef03 22 #include <stddef.h>
kevman 0:38ceb79fef03 23 #include <stdint.h>
kevman 0:38ceb79fef03 24
kevman 0:38ceb79fef03 25 /** CRC Polynomial value
kevman 0:38ceb79fef03 26 *
kevman 0:38ceb79fef03 27 * Different polynomial values supported
kevman 0:38ceb79fef03 28 */
kevman 0:38ceb79fef03 29 typedef enum crc_polynomial {
kevman 0:38ceb79fef03 30 POLY_OTHER = 0,
kevman 0:38ceb79fef03 31 POLY_8BIT_CCITT = 0x07, // x8+x2+x+1
kevman 0:38ceb79fef03 32 POLY_7BIT_SD = 0x9, // x7+x3+1;
kevman 0:38ceb79fef03 33 POLY_16BIT_CCITT = 0x1021, // x16+x12+x5+1
kevman 0:38ceb79fef03 34 POLY_16BIT_IBM = 0x8005, // x16+x15+x2+1
kevman 0:38ceb79fef03 35 POLY_32BIT_ANSI = 0x04C11DB7, // x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
kevman 0:38ceb79fef03 36 POLY_32BIT_REV_ANSI = 0xEDB88320
kevman 0:38ceb79fef03 37 } crc_polynomial_t;
kevman 0:38ceb79fef03 38
kevman 0:38ceb79fef03 39 typedef struct crc_mbed_config {
kevman 0:38ceb79fef03 40 /** CRC Polynomial. Example polynomial: 0x21 = 0010_0011 = x^5+x+1 */
kevman 0:38ceb79fef03 41 uint32_t polynomial;
kevman 0:38ceb79fef03 42 /** CRC Bit Width */
kevman 0:38ceb79fef03 43 uint32_t width;
kevman 0:38ceb79fef03 44 /** Initial seed value for the computation. */
kevman 0:38ceb79fef03 45 uint32_t initial_xor;
kevman 0:38ceb79fef03 46 /** Final xor value for the computation. */
kevman 0:38ceb79fef03 47 uint32_t final_xor;
kevman 0:38ceb79fef03 48 /** Reflect bits on input. */
kevman 0:38ceb79fef03 49 bool reflect_in;
kevman 0:38ceb79fef03 50 /** Reflect bits in final result before returning. */
kevman 0:38ceb79fef03 51 bool reflect_out;
kevman 0:38ceb79fef03 52 } crc_mbed_config_t;
kevman 0:38ceb79fef03 53
kevman 0:38ceb79fef03 54 #ifdef DEVICE_CRC
kevman 0:38ceb79fef03 55
kevman 0:38ceb79fef03 56 #ifdef __cplusplus
kevman 0:38ceb79fef03 57 extern "C" {
kevman 0:38ceb79fef03 58 #endif
kevman 0:38ceb79fef03 59
kevman 0:38ceb79fef03 60 /**
kevman 0:38ceb79fef03 61 * \defgroup hal_crc Hardware CRC
kevman 0:38ceb79fef03 62 *
kevman 0:38ceb79fef03 63 * The Hardware CRC HAL API provides a low-level interface to the Hardware CRC
kevman 0:38ceb79fef03 64 * module of a target platform.
kevman 0:38ceb79fef03 65 *
kevman 0:38ceb79fef03 66 * # Defined behaviour
kevman 0:38ceb79fef03 67 *
kevman 0:38ceb79fef03 68 * * Function hal_crc_is_supported() returns true if platform supports hardware
kevman 0:38ceb79fef03 69 * CRC for the given polynomial/width - verified by test ::crc_is_supported_test.
kevman 0:38ceb79fef03 70 * * Function hal_crc_is_supported() returns false if platform does not support hardware
kevman 0:38ceb79fef03 71 * CRC for the given polynomial/width - verified by test ::crc_is_supported_test.
kevman 0:38ceb79fef03 72 * * Function hal_crc_is_supported() returns false if given pointer to configuration
kevman 0:38ceb79fef03 73 * structure is undefined (NULL) - verified by test ::crc_is_supported_invalid_param_test.
kevman 0:38ceb79fef03 74 * * If CRC module does not support one of the following settings: initial_xor, final_xor
kevman 0:38ceb79fef03 75 * reflect_in, reflect_out, then these operations should be handled by the driver
kevman 0:38ceb79fef03 76 * - Verified by test ::crc_calc_single_test.
kevman 0:38ceb79fef03 77 * * Platform which supports hardware CRC must be able to handle at least one of the predefined
kevman 0:38ceb79fef03 78 * polynomial/width configurations that can be constructed in the MbedCRC class: POLY_8BIT_CCITT,
kevman 0:38ceb79fef03 79 * POLY_7BIT_SD, POLY_16BIT_CCITT, POLY_16BIT_IBM, POLY_32BIT_ANSI
kevman 0:38ceb79fef03 80 * - verified by test ::crc_is_supported_test, ::crc_calc_single_test.
kevman 0:38ceb79fef03 81 * * Function hal_crc_compute_partial_start() configures CRC module with the given configuration
kevman 0:38ceb79fef03 82 * - Verified by test ::crc_calc_single_test.
kevman 0:38ceb79fef03 83 * * Calling hal_crc_compute_partial_start() without finalising the
kevman 0:38ceb79fef03 84 * CRC calculation overrides the current configuration - Verified by test ::crc_reconfigure_test.
kevman 0:38ceb79fef03 85 * * Function hal_crc_compute_partial() writes data to the CRC module - verified by test ::crc_calc_single_test.
kevman 0:38ceb79fef03 86 * * Function hal_crc_compute_partial() can be call multiple times in succession in order to
kevman 0:38ceb79fef03 87 * provide additional data to CRC module - verified by test ::crc_calc_multi_test.
kevman 0:38ceb79fef03 88 * * Function hal_crc_compute_partial() does nothing if pointer to buffer is undefined or
kevman 0:38ceb79fef03 89 * data length is equal to 0 - verified by test ::crc_compute_partial_invalid_param_test.
kevman 0:38ceb79fef03 90 * * Function hal_crc_get_result() returns the checksum result from the CRC module
kevman 0:38ceb79fef03 91 * - verified by tests ::crc_calc_single_test, ::crc_calc_multi_test, ::crc_reconfigure_test.
kevman 0:38ceb79fef03 92 *
kevman 0:38ceb79fef03 93 * # Undefined behaviour
kevman 0:38ceb79fef03 94 *
kevman 0:38ceb79fef03 95 * * Calling hal_crc_compute_partial_start() function with invalid (unsupported) polynomial.
kevman 0:38ceb79fef03 96 * * Calling hal_crc_compute_partial() or hal_crc_get_result() functions before hal_crc_compute_partial_start().
kevman 0:38ceb79fef03 97 * * Calling hal_crc_get_result() function multiple times.
kevman 0:38ceb79fef03 98 *
kevman 0:38ceb79fef03 99 * # Non-functional requirements
kevman 0:38ceb79fef03 100 *
kevman 0:38ceb79fef03 101 * * CRC configuration provides the following settings:
kevman 0:38ceb79fef03 102 * * polynomial - CRC Polynomial,
kevman 0:38ceb79fef03 103 * * width - CRC bit width,
kevman 0:38ceb79fef03 104 * * initial_xor - seed value for the computation,
kevman 0:38ceb79fef03 105 * * final_xor - final xor value for the computation,
kevman 0:38ceb79fef03 106 * * reflect_in - reflect bits on input,
kevman 0:38ceb79fef03 107 * * reflect_out - reflect bits in final result before returning.
kevman 0:38ceb79fef03 108 *
kevman 0:38ceb79fef03 109 * # Potential bugs
kevman 0:38ceb79fef03 110 *
kevman 0:38ceb79fef03 111 * @{
kevman 0:38ceb79fef03 112 */
kevman 0:38ceb79fef03 113
kevman 0:38ceb79fef03 114 /**
kevman 0:38ceb79fef03 115 * \defgroup hal_crc_tests crc hal tests
kevman 0:38ceb79fef03 116 * The crc HAL tests ensure driver conformance to defined behaviour.
kevman 0:38ceb79fef03 117 *
kevman 0:38ceb79fef03 118 * To run the crc hal tests use the command:
kevman 0:38ceb79fef03 119 *
kevman 0:38ceb79fef03 120 * mbed test -t <toolchain> -m <target> -n tests-mbed_hal-crc*
kevman 0:38ceb79fef03 121 *
kevman 0:38ceb79fef03 122 */
kevman 0:38ceb79fef03 123
kevman 0:38ceb79fef03 124 /** Determine if the current platform supports hardware CRC for given polynomial
kevman 0:38ceb79fef03 125 *
kevman 0:38ceb79fef03 126 * The purpose of this function is to inform the CRC Platform API whether the
kevman 0:38ceb79fef03 127 * current platform has a hardware CRC module and that it can support the
kevman 0:38ceb79fef03 128 * requested polynomial.
kevman 0:38ceb79fef03 129 *
kevman 0:38ceb79fef03 130 * Supported polynomials are restricted to the named polynomials that can be
kevman 0:38ceb79fef03 131 * constructed in the MbedCRC class, POLY_8BIT_CCITT, POLY_7BIT_SD,
kevman 0:38ceb79fef03 132 * POLY_16BIT_CCITT, POLY_16BIT_IBM and POLY_32BIT_ANSI.
kevman 0:38ceb79fef03 133 *
kevman 0:38ceb79fef03 134 * The current platform must support the given polynomials default parameters
kevman 0:38ceb79fef03 135 * in order to return a true response. These include: reflect in, reflect out,
kevman 0:38ceb79fef03 136 * initial xor and final xor. For example, POLY_32BIT_ANSI requires an initial
kevman 0:38ceb79fef03 137 * and final xor of 0xFFFFFFFF, and reflection of both input and output. If any
kevman 0:38ceb79fef03 138 * of these settings cannot be configured, the polynomial is not supported.
kevman 0:38ceb79fef03 139 *
kevman 0:38ceb79fef03 140 * This function is thread safe; it safe to call from multiple contexts if
kevman 0:38ceb79fef03 141 * required.
kevman 0:38ceb79fef03 142 *
kevman 0:38ceb79fef03 143 * \param config Contains CRC configuration parameters for initializing the
kevman 0:38ceb79fef03 144 * hardware CRC module. For example, polynomial and initial seed
kevman 0:38ceb79fef03 145 * values.
kevman 0:38ceb79fef03 146 *
kevman 0:38ceb79fef03 147 * \return True if running if the polynomial is supported, false if not.
kevman 0:38ceb79fef03 148 */
kevman 0:38ceb79fef03 149 bool hal_crc_is_supported(const crc_mbed_config_t *config);
kevman 0:38ceb79fef03 150
kevman 0:38ceb79fef03 151 /** Initialize the hardware CRC module with the given polynomial
kevman 0:38ceb79fef03 152 *
kevman 0:38ceb79fef03 153 * After calling this function, the CRC HAL module is ready to receive data
kevman 0:38ceb79fef03 154 * using the hal_crc_compute_partial() function. The CRC module on the board
kevman 0:38ceb79fef03 155 * is configured internally with the specified configuration and is ready
kevman 0:38ceb79fef03 156 * to receive data.
kevman 0:38ceb79fef03 157 *
kevman 0:38ceb79fef03 158 * The platform configures itself based on the default configuration
kevman 0:38ceb79fef03 159 * parameters of the input polynomial.
kevman 0:38ceb79fef03 160 *
kevman 0:38ceb79fef03 161 * This function must be called before calling hal_crc_compute_partial().
kevman 0:38ceb79fef03 162 *
kevman 0:38ceb79fef03 163 * This function must be called with a valid polynomial supported by the
kevman 0:38ceb79fef03 164 * platform. The polynomial must be checked for support using the
kevman 0:38ceb79fef03 165 * hal_crc_is_supported() function.
kevman 0:38ceb79fef03 166 *
kevman 0:38ceb79fef03 167 * Calling hal_crc_compute_partial_start() multiple times without finalizing the
kevman 0:38ceb79fef03 168 * CRC calculation with hal_crc_get_result() overrides the current
kevman 0:38ceb79fef03 169 * configuration and state, and the intermediate result of the computation is
kevman 0:38ceb79fef03 170 * lost.
kevman 0:38ceb79fef03 171 *
kevman 0:38ceb79fef03 172 * This function is not thread safe. A CRC calculation must not be started from
kevman 0:38ceb79fef03 173 * two different threads or contexts at the same time; calling this function
kevman 0:38ceb79fef03 174 * from two different contexts may lead to configurations being overwritten and
kevman 0:38ceb79fef03 175 * results being lost.
kevman 0:38ceb79fef03 176 *
kevman 0:38ceb79fef03 177 * \param config Contains CRC configuration parameters for initializing the
kevman 0:38ceb79fef03 178 * hardware CRC module. For example, polynomial and initial seed
kevman 0:38ceb79fef03 179 * values.
kevman 0:38ceb79fef03 180 */
kevman 0:38ceb79fef03 181 void hal_crc_compute_partial_start(const crc_mbed_config_t *config);
kevman 0:38ceb79fef03 182
kevman 0:38ceb79fef03 183 /** Writes data to the current CRC module.
kevman 0:38ceb79fef03 184 *
kevman 0:38ceb79fef03 185 * Writes input data buffer bytes to the CRC data register. The CRC module
kevman 0:38ceb79fef03 186 * must interpret the data as an array of bytes.
kevman 0:38ceb79fef03 187 *
kevman 0:38ceb79fef03 188 * The final transformations are not applied to the data; the CRC module must
kevman 0:38ceb79fef03 189 * retain the intermediate result so that additional calls to this function
kevman 0:38ceb79fef03 190 * can be made, appending the additional data to the calculation.
kevman 0:38ceb79fef03 191 *
kevman 0:38ceb79fef03 192 * To obtain the final result of the CRC calculation, hal_crc_get_result() is
kevman 0:38ceb79fef03 193 * called to apply the final transformations to the data.
kevman 0:38ceb79fef03 194 *
kevman 0:38ceb79fef03 195 * If the function is passed an undefined pointer, or the size of the buffer is
kevman 0:38ceb79fef03 196 * specified to be 0, this function does nothing and returns.
kevman 0:38ceb79fef03 197 *
kevman 0:38ceb79fef03 198 * This function can be called multiple times in succession. This can be used
kevman 0:38ceb79fef03 199 * to calculate the CRC result of streamed data.
kevman 0:38ceb79fef03 200 *
kevman 0:38ceb79fef03 201 * This function is not thread safe. There is only one instance of the CRC
kevman 0:38ceb79fef03 202 * module active at a time. Calling this function from multiple contexts
kevman 0:38ceb79fef03 203 * appends different data to the same, single instance of the module, which causes an
kevman 0:38ceb79fef03 204 * erroneous value to be calculated.
kevman 0:38ceb79fef03 205 *
kevman 0:38ceb79fef03 206 * \param data Input data stream to be written into the CRC calculation
kevman 0:38ceb79fef03 207 * \param size Size of the data stream in bytes
kevman 0:38ceb79fef03 208 */
kevman 0:38ceb79fef03 209 void hal_crc_compute_partial(const uint8_t *data, const size_t size);
kevman 0:38ceb79fef03 210
kevman 0:38ceb79fef03 211 /* Reads the checksum result from the CRC module.
kevman 0:38ceb79fef03 212 *
kevman 0:38ceb79fef03 213 * Reads the final checksum result for the final checksum value. The returned
kevman 0:38ceb79fef03 214 * value is cast as an unsigned 32-bit integer. The actual size of the returned
kevman 0:38ceb79fef03 215 * result depends on the polynomial used to configure the CRC module.
kevman 0:38ceb79fef03 216 *
kevman 0:38ceb79fef03 217 * Additional transformations that are used in the default configuration of the
kevman 0:38ceb79fef03 218 * input polynomial are applied to the result before it is returned from this
kevman 0:38ceb79fef03 219 * function. These transformations include: the final xor being appended to the
kevman 0:38ceb79fef03 220 * calculation, and the result being reflected if required.
kevman 0:38ceb79fef03 221 *
kevman 0:38ceb79fef03 222 * Calling this function multiple times is undefined. The first call to this
kevman 0:38ceb79fef03 223 * function returns the final result of the CRC calculation. The return
kevman 0:38ceb79fef03 224 * value on successive calls is undefined because the contents of the register after
kevman 0:38ceb79fef03 225 * accessing them is platform-specific.
kevman 0:38ceb79fef03 226 *
kevman 0:38ceb79fef03 227 * This function is not thread safe. There is only one instance of the CRC
kevman 0:38ceb79fef03 228 * module active at a time. Calling this function from multiple contexts may
kevman 0:38ceb79fef03 229 * return incorrect data or affect the current state of the module.
kevman 0:38ceb79fef03 230 *
kevman 0:38ceb79fef03 231 * \return The final CRC checksum after the reflections and final calculations
kevman 0:38ceb79fef03 232 * have been applied.
kevman 0:38ceb79fef03 233 */
kevman 0:38ceb79fef03 234 uint32_t hal_crc_get_result(void);
kevman 0:38ceb79fef03 235
kevman 0:38ceb79fef03 236 /**@}*/
kevman 0:38ceb79fef03 237
kevman 0:38ceb79fef03 238 #ifdef __cplusplus
kevman 0:38ceb79fef03 239 };
kevman 0:38ceb79fef03 240 #endif
kevman 0:38ceb79fef03 241
kevman 0:38ceb79fef03 242 #endif // DEVICE_CRC
kevman 0:38ceb79fef03 243 #endif // MBED_CRC_HAL_API_H
kevman 0:38ceb79fef03 244
kevman 0:38ceb79fef03 245 /**@}*/