mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

drivers/MbedCRC.h@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
188:bcfe06ba3d64 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 184:08ed48f1de7f 1 /* mbed Microcontroller Library
AnnaBridge 184:08ed48f1de7f 2 * Copyright (c) 2018 ARM Limited
AnnaBridge 189:f392fc9709a3 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 184:08ed48f1de7f 4 *
AnnaBridge 184:08ed48f1de7f 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 184:08ed48f1de7f 6 * you may not use this file except in compliance with the License.
AnnaBridge 184:08ed48f1de7f 7 * You may obtain a copy of the License at
AnnaBridge 184:08ed48f1de7f 8 *
AnnaBridge 184:08ed48f1de7f 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 184:08ed48f1de7f 10 *
AnnaBridge 184:08ed48f1de7f 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 184:08ed48f1de7f 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 184:08ed48f1de7f 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 184:08ed48f1de7f 14 * See the License for the specific language governing permissions and
AnnaBridge 184:08ed48f1de7f 15 * limitations under the License.
AnnaBridge 184:08ed48f1de7f 16 */
AnnaBridge 184:08ed48f1de7f 17 #ifndef MBED_CRC_API_H
AnnaBridge 184:08ed48f1de7f 18 #define MBED_CRC_API_H
AnnaBridge 184:08ed48f1de7f 19
AnnaBridge 184:08ed48f1de7f 20 #include "drivers/TableCRC.h"
Anna Bridge 186:707f6e361f3e 21 #include "hal/crc_api.h"
AnnaBridge 184:08ed48f1de7f 22 #include "platform/mbed_assert.h"
AnnaBridge 188:bcfe06ba3d64 23 #include "platform/SingletonPtr.h"
AnnaBridge 188:bcfe06ba3d64 24 #include "platform/PlatformMutex.h"
AnnaBridge 184:08ed48f1de7f 25
AnnaBridge 184:08ed48f1de7f 26 /* This is invalid warning from the compiler for below section of code
AnnaBridge 184:08ed48f1de7f 27 if ((width < 8) && (NULL == _crc_table)) {
AnnaBridge 184:08ed48f1de7f 28 p_crc = (uint32_t)(p_crc << (8 - width));
AnnaBridge 184:08ed48f1de7f 29 }
AnnaBridge 184:08ed48f1de7f 30 Compiler warns of the shift operation with width as it is width=(std::uint8_t),
AnnaBridge 184:08ed48f1de7f 31 but we check for ( width < 8) before performing shift, so it should not be an issue.
AnnaBridge 184:08ed48f1de7f 32 */
AnnaBridge 184:08ed48f1de7f 33 #if defined ( __CC_ARM )
AnnaBridge 184:08ed48f1de7f 34 #pragma diag_suppress 62 // Shift count is negative
AnnaBridge 184:08ed48f1de7f 35 #elif defined ( __GNUC__ )
AnnaBridge 184:08ed48f1de7f 36 #pragma GCC diagnostic push
AnnaBridge 184:08ed48f1de7f 37 #pragma GCC diagnostic ignored "-Wshift-count-negative"
AnnaBridge 187:0387e8f68319 38 #elif defined (__ICCARM__)
AnnaBridge 187:0387e8f68319 39 #pragma diag_suppress=Pe062 // Shift count is negative
AnnaBridge 184:08ed48f1de7f 40 #endif
AnnaBridge 184:08ed48f1de7f 41
AnnaBridge 184:08ed48f1de7f 42 namespace mbed {
AnnaBridge 184:08ed48f1de7f 43 /** \addtogroup drivers */
AnnaBridge 184:08ed48f1de7f 44 /** @{*/
AnnaBridge 184:08ed48f1de7f 45
AnnaBridge 184:08ed48f1de7f 46 /** CRC object provides CRC generation through hardware/software
AnnaBridge 184:08ed48f1de7f 47 *
AnnaBridge 184:08ed48f1de7f 48 * ROM polynomial tables for supported polynomials (:: crc_polynomial_t) will be used for
AnnaBridge 184:08ed48f1de7f 49 * software CRC computation, if ROM tables are not available then CRC is computed runtime
AnnaBridge 184:08ed48f1de7f 50 * bit by bit for all data input.
AnnaBridge 188:bcfe06ba3d64 51 * @note Synchronization level: Thread safe
AnnaBridge 184:08ed48f1de7f 52 *
AnnaBridge 184:08ed48f1de7f 53 * @tparam polynomial CRC polynomial value in hex
AnnaBridge 184:08ed48f1de7f 54 * @tparam width CRC polynomial width
AnnaBridge 184:08ed48f1de7f 55 *
AnnaBridge 184:08ed48f1de7f 56 * Example: Compute CRC data
AnnaBridge 184:08ed48f1de7f 57 * @code
AnnaBridge 184:08ed48f1de7f 58 *
AnnaBridge 184:08ed48f1de7f 59 * #include "mbed.h"
AnnaBridge 184:08ed48f1de7f 60 *
AnnaBridge 184:08ed48f1de7f 61 * int main() {
AnnaBridge 184:08ed48f1de7f 62 * MbedCRC<POLY_32BIT_ANSI, 32> ct;
AnnaBridge 184:08ed48f1de7f 63 *
AnnaBridge 184:08ed48f1de7f 64 * char test[] = "123456789";
AnnaBridge 184:08ed48f1de7f 65 * uint32_t crc = 0;
AnnaBridge 184:08ed48f1de7f 66 *
AnnaBridge 184:08ed48f1de7f 67 * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width());
AnnaBridge 184:08ed48f1de7f 68 *
AnnaBridge 184:08ed48f1de7f 69 * ct.compute((void *)test, strlen((const char*)test), &crc);
AnnaBridge 184:08ed48f1de7f 70 *
AnnaBridge 184:08ed48f1de7f 71 * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc);
AnnaBridge 184:08ed48f1de7f 72 * return 0;
AnnaBridge 184:08ed48f1de7f 73 * }
AnnaBridge 184:08ed48f1de7f 74 * @endcode
AnnaBridge 184:08ed48f1de7f 75 * Example: Compute CRC with data available in parts
AnnaBridge 184:08ed48f1de7f 76 * @code
AnnaBridge 184:08ed48f1de7f 77 *
AnnaBridge 184:08ed48f1de7f 78 * #include "mbed.h"
AnnaBridge 184:08ed48f1de7f 79 * int main() {
AnnaBridge 184:08ed48f1de7f 80 * MbedCRC<POLY_32BIT_ANSI, 32> ct;
AnnaBridge 184:08ed48f1de7f 81 *
AnnaBridge 184:08ed48f1de7f 82 * char test[] = "123456789";
AnnaBridge 184:08ed48f1de7f 83 * uint32_t crc = 0;
AnnaBridge 184:08ed48f1de7f 84 *
AnnaBridge 184:08ed48f1de7f 85 * printf("\nPolynomial = 0x%lx Width = %d \n", ct.get_polynomial(), ct.get_width());
AnnaBridge 184:08ed48f1de7f 86 * ct.compute_partial_start(&crc);
AnnaBridge 184:08ed48f1de7f 87 * ct.compute_partial((void *)&test, 4, &crc);
AnnaBridge 184:08ed48f1de7f 88 * ct.compute_partial((void *)&test[4], 5, &crc);
AnnaBridge 184:08ed48f1de7f 89 * ct.compute_partial_stop(&crc);
AnnaBridge 184:08ed48f1de7f 90 * printf("The CRC of data \"123456789\" is : 0x%lx\n", crc);
AnnaBridge 184:08ed48f1de7f 91 * return 0;
AnnaBridge 184:08ed48f1de7f 92 * }
AnnaBridge 184:08ed48f1de7f 93 * @endcode
AnnaBridge 184:08ed48f1de7f 94 * @ingroup drivers
AnnaBridge 184:08ed48f1de7f 95 */
AnnaBridge 184:08ed48f1de7f 96
AnnaBridge 188:bcfe06ba3d64 97 extern SingletonPtr<PlatformMutex> mbed_crc_mutex;
AnnaBridge 188:bcfe06ba3d64 98
AnnaBridge 187:0387e8f68319 99 template <uint32_t polynomial = POLY_32BIT_ANSI, uint8_t width = 32>
AnnaBridge 187:0387e8f68319 100 class MbedCRC {
Anna Bridge 186:707f6e361f3e 101
Anna Bridge 186:707f6e361f3e 102 public:
AnnaBridge 189:f392fc9709a3 103 enum CrcMode {
AnnaBridge 189:f392fc9709a3 104 #if DEVICE_CRC
AnnaBridge 188:bcfe06ba3d64 105 HARDWARE = 0,
AnnaBridge 188:bcfe06ba3d64 106 #endif
AnnaBridge 188:bcfe06ba3d64 107 TABLE = 1,
AnnaBridge 188:bcfe06ba3d64 108 BITWISE
AnnaBridge 188:bcfe06ba3d64 109 };
AnnaBridge 188:bcfe06ba3d64 110
AnnaBridge 184:08ed48f1de7f 111 typedef uint64_t crc_data_size_t;
AnnaBridge 184:08ed48f1de7f 112
AnnaBridge 184:08ed48f1de7f 113 /** Lifetime of CRC object
AnnaBridge 184:08ed48f1de7f 114 *
AnnaBridge 184:08ed48f1de7f 115 * @param initial_xor Inital value/seed to Xor
AnnaBridge 184:08ed48f1de7f 116 * @param final_xor Final Xor value
AnnaBridge 184:08ed48f1de7f 117 * @param reflect_data
AnnaBridge 184:08ed48f1de7f 118 * @param reflect_remainder
AnnaBridge 188:bcfe06ba3d64 119 * @note Default constructor without any arguments is valid only for supported CRC polynomials. :: crc_polynomial_t
AnnaBridge 184:08ed48f1de7f 120 * MbedCRC <POLY_7BIT_SD, 7> ct; --- Valid POLY_7BIT_SD
AnnaBridge 184:08ed48f1de7f 121 * MbedCRC <0x1021, 16> ct; --- Valid POLY_16BIT_CCITT
AnnaBridge 184:08ed48f1de7f 122 * MbedCRC <POLY_16BIT_CCITT, 32> ct; --- Invalid, compilation error
AnnaBridge 188:bcfe06ba3d64 123 * MbedCRC <POLY_16BIT_CCITT, 32> ct (i,f,rd,rr) Constructor can be used for not supported polynomials
AnnaBridge 184:08ed48f1de7f 124 * MbedCRC<POLY_16BIT_CCITT, 16> sd(0, 0, false, false); Constructor can also be used for supported
AnnaBridge 184:08ed48f1de7f 125 * polynomials with different intial/final/reflect values
AnnaBridge 184:08ed48f1de7f 126 *
AnnaBridge 184:08ed48f1de7f 127 */
AnnaBridge 184:08ed48f1de7f 128 MbedCRC(uint32_t initial_xor, uint32_t final_xor, bool reflect_data, bool reflect_remainder) :
AnnaBridge 187:0387e8f68319 129 _initial_value(initial_xor), _final_xor(final_xor), _reflect_data(reflect_data),
AnnaBridge 188:bcfe06ba3d64 130 _reflect_remainder(reflect_remainder)
AnnaBridge 184:08ed48f1de7f 131 {
AnnaBridge 184:08ed48f1de7f 132 mbed_crc_ctor();
AnnaBridge 184:08ed48f1de7f 133 }
AnnaBridge 184:08ed48f1de7f 134 MbedCRC();
AnnaBridge 184:08ed48f1de7f 135 virtual ~MbedCRC()
AnnaBridge 184:08ed48f1de7f 136 {
AnnaBridge 184:08ed48f1de7f 137 // Do nothing
AnnaBridge 184:08ed48f1de7f 138 }
AnnaBridge 184:08ed48f1de7f 139
AnnaBridge 184:08ed48f1de7f 140 /** Compute CRC for the data input
AnnaBridge 188:bcfe06ba3d64 141 * Compute CRC performs the initialization, computation and collection of
AnnaBridge 188:bcfe06ba3d64 142 * final CRC.
AnnaBridge 184:08ed48f1de7f 143 *
AnnaBridge 184:08ed48f1de7f 144 * @param buffer Data bytes
AnnaBridge 184:08ed48f1de7f 145 * @param size Size of data
AnnaBridge 184:08ed48f1de7f 146 * @param crc CRC is the output value
AnnaBridge 184:08ed48f1de7f 147 * @return 0 on success, negative error code on failure
AnnaBridge 184:08ed48f1de7f 148 */
AnnaBridge 184:08ed48f1de7f 149 int32_t compute(void *buffer, crc_data_size_t size, uint32_t *crc)
AnnaBridge 184:08ed48f1de7f 150 {
AnnaBridge 184:08ed48f1de7f 151 MBED_ASSERT(crc != NULL);
AnnaBridge 188:bcfe06ba3d64 152 int32_t status = 0;
AnnaBridge 188:bcfe06ba3d64 153
AnnaBridge 188:bcfe06ba3d64 154 status = compute_partial_start(crc);
AnnaBridge 188:bcfe06ba3d64 155 if (0 != status) {
AnnaBridge 188:bcfe06ba3d64 156 unlock();
AnnaBridge 184:08ed48f1de7f 157 return status;
AnnaBridge 184:08ed48f1de7f 158 }
AnnaBridge 188:bcfe06ba3d64 159
AnnaBridge 188:bcfe06ba3d64 160 status = compute_partial(buffer, size, crc);
AnnaBridge 188:bcfe06ba3d64 161 if (0 != status) {
AnnaBridge 188:bcfe06ba3d64 162 unlock();
AnnaBridge 184:08ed48f1de7f 163 return status;
AnnaBridge 184:08ed48f1de7f 164 }
AnnaBridge 188:bcfe06ba3d64 165
AnnaBridge 188:bcfe06ba3d64 166 status = compute_partial_stop(crc);
AnnaBridge 188:bcfe06ba3d64 167 if (0 != status) {
AnnaBridge 189:f392fc9709a3 168 *crc = 0;
AnnaBridge 184:08ed48f1de7f 169 }
AnnaBridge 188:bcfe06ba3d64 170
AnnaBridge 188:bcfe06ba3d64 171 return status;
AnnaBridge 188:bcfe06ba3d64 172
AnnaBridge 184:08ed48f1de7f 173 }
AnnaBridge 184:08ed48f1de7f 174
AnnaBridge 184:08ed48f1de7f 175 /** Compute partial CRC for the data input.
AnnaBridge 184:08ed48f1de7f 176 *
AnnaBridge 184:08ed48f1de7f 177 * CRC data if not available fully, CRC can be computed in parts with available data.
AnnaBridge 188:bcfe06ba3d64 178 *
AnnaBridge 188:bcfe06ba3d64 179 * In case of hardware, intermediate values and states are saved by hardware. Mutex
AnnaBridge 188:bcfe06ba3d64 180 * locking is used to serialize access to hardware CRC.
AnnaBridge 188:bcfe06ba3d64 181 *
AnnaBridge 188:bcfe06ba3d64 182 * In case of software CRC, previous CRC output should be passed as argument to the
AnnaBridge 188:bcfe06ba3d64 183 * current compute_partial call. Please note the intermediate CRC value is maintained by
AnnaBridge 188:bcfe06ba3d64 184 * application and not the driver.
AnnaBridge 188:bcfe06ba3d64 185 *
AnnaBridge 188:bcfe06ba3d64 186 * @pre: Call `compute_partial_start` to start the partial CRC calculation.
AnnaBridge 188:bcfe06ba3d64 187 * @post: Call `compute_partial_stop` to get the final CRC value.
AnnaBridge 184:08ed48f1de7f 188 *
AnnaBridge 184:08ed48f1de7f 189 * @param buffer Data bytes
AnnaBridge 184:08ed48f1de7f 190 * @param size Size of data
AnnaBridge 184:08ed48f1de7f 191 * @param crc CRC value is intermediate CRC value filled by API.
AnnaBridge 184:08ed48f1de7f 192 * @return 0 on success or a negative error code on failure
AnnaBridge 188:bcfe06ba3d64 193 * @note: CRC as output in compute_partial is not final CRC value, call `compute_partial_stop`
AnnaBridge 184:08ed48f1de7f 194 * to get final correct CRC value.
AnnaBridge 184:08ed48f1de7f 195 */
AnnaBridge 184:08ed48f1de7f 196 int32_t compute_partial(void *buffer, crc_data_size_t size, uint32_t *crc)
AnnaBridge 184:08ed48f1de7f 197 {
AnnaBridge 188:bcfe06ba3d64 198 int32_t status = 0;
AnnaBridge 188:bcfe06ba3d64 199
AnnaBridge 187:0387e8f68319 200 switch (_mode) {
AnnaBridge 189:f392fc9709a3 201 #if DEVICE_CRC
AnnaBridge 188:bcfe06ba3d64 202 case HARDWARE:
Anna Bridge 186:707f6e361f3e 203 hal_crc_compute_partial((uint8_t *)buffer, size);
Anna Bridge 186:707f6e361f3e 204 *crc = 0;
AnnaBridge 188:bcfe06ba3d64 205 break;
AnnaBridge 188:bcfe06ba3d64 206 #endif
Anna Bridge 186:707f6e361f3e 207 case TABLE:
AnnaBridge 188:bcfe06ba3d64 208 status = table_compute_partial(buffer, size, crc);
AnnaBridge 188:bcfe06ba3d64 209 break;
Anna Bridge 186:707f6e361f3e 210 case BITWISE:
AnnaBridge 188:bcfe06ba3d64 211 status = bitwise_compute_partial(buffer, size, crc);
AnnaBridge 188:bcfe06ba3d64 212 break;
AnnaBridge 188:bcfe06ba3d64 213 default:
AnnaBridge 188:bcfe06ba3d64 214 status = -1;
AnnaBridge 188:bcfe06ba3d64 215 break;
AnnaBridge 184:08ed48f1de7f 216 }
Anna Bridge 186:707f6e361f3e 217
AnnaBridge 188:bcfe06ba3d64 218 return status;
AnnaBridge 184:08ed48f1de7f 219 }
AnnaBridge 184:08ed48f1de7f 220
AnnaBridge 188:bcfe06ba3d64 221 /** Compute partial start, indicate start of partial computation.
AnnaBridge 184:08ed48f1de7f 222 *
AnnaBridge 184:08ed48f1de7f 223 * This API should be called before performing any partial computation
AnnaBridge 184:08ed48f1de7f 224 * with compute_partial API.
AnnaBridge 184:08ed48f1de7f 225 *
AnnaBridge 184:08ed48f1de7f 226 * @param crc Initial CRC value set by the API
AnnaBridge 184:08ed48f1de7f 227 * @return 0 on success or a negative in case of failure
AnnaBridge 184:08ed48f1de7f 228 * @note: CRC is an out parameter and must be reused with compute_partial
AnnaBridge 188:bcfe06ba3d64 229 * and `compute_partial_stop` without any modifications in application.
AnnaBridge 184:08ed48f1de7f 230 */
AnnaBridge 184:08ed48f1de7f 231 int32_t compute_partial_start(uint32_t *crc)
AnnaBridge 184:08ed48f1de7f 232 {
AnnaBridge 184:08ed48f1de7f 233 MBED_ASSERT(crc != NULL);
Anna Bridge 186:707f6e361f3e 234
AnnaBridge 189:f392fc9709a3 235 #if DEVICE_CRC
Anna Bridge 186:707f6e361f3e 236 if (_mode == HARDWARE) {
AnnaBridge 188:bcfe06ba3d64 237 lock();
Anna Bridge 186:707f6e361f3e 238 crc_mbed_config_t config;
Anna Bridge 186:707f6e361f3e 239 config.polynomial = polynomial;
Anna Bridge 186:707f6e361f3e 240 config.width = width;
Anna Bridge 186:707f6e361f3e 241 config.initial_xor = _initial_value;
Anna Bridge 186:707f6e361f3e 242 config.final_xor = _final_xor;
Anna Bridge 186:707f6e361f3e 243 config.reflect_in = _reflect_data;
Anna Bridge 186:707f6e361f3e 244 config.reflect_out = _reflect_remainder;
Anna Bridge 186:707f6e361f3e 245
Anna Bridge 186:707f6e361f3e 246 hal_crc_compute_partial_start(&config);
Anna Bridge 186:707f6e361f3e 247 }
AnnaBridge 188:bcfe06ba3d64 248 #endif
Anna Bridge 186:707f6e361f3e 249
AnnaBridge 184:08ed48f1de7f 250 *crc = _initial_value;
AnnaBridge 184:08ed48f1de7f 251 return 0;
AnnaBridge 184:08ed48f1de7f 252 }
AnnaBridge 184:08ed48f1de7f 253
AnnaBridge 184:08ed48f1de7f 254 /** Get the final CRC value of partial computation.
AnnaBridge 184:08ed48f1de7f 255 *
AnnaBridge 184:08ed48f1de7f 256 * CRC value available in partial computation is not correct CRC, as some
AnnaBridge 184:08ed48f1de7f 257 * algorithms require remainder to be reflected and final value to be XORed
AnnaBridge 184:08ed48f1de7f 258 * This API is used to perform final computation to get correct CRC value.
AnnaBridge 184:08ed48f1de7f 259 *
AnnaBridge 184:08ed48f1de7f 260 * @param crc CRC result
AnnaBridge 188:bcfe06ba3d64 261 * @return 0 on success or a negative in case of failure.
AnnaBridge 184:08ed48f1de7f 262 */
AnnaBridge 184:08ed48f1de7f 263 int32_t compute_partial_stop(uint32_t *crc)
AnnaBridge 184:08ed48f1de7f 264 {
AnnaBridge 184:08ed48f1de7f 265 MBED_ASSERT(crc != NULL);
Anna Bridge 186:707f6e361f3e 266
AnnaBridge 189:f392fc9709a3 267 #if DEVICE_CRC
Anna Bridge 186:707f6e361f3e 268 if (_mode == HARDWARE) {
Anna Bridge 186:707f6e361f3e 269 *crc = hal_crc_get_result();
AnnaBridge 188:bcfe06ba3d64 270 unlock();
Anna Bridge 186:707f6e361f3e 271 return 0;
AnnaBridge 188:bcfe06ba3d64 272 }
Anna Bridge 186:707f6e361f3e 273 #endif
AnnaBridge 184:08ed48f1de7f 274 uint32_t p_crc = *crc;
AnnaBridge 184:08ed48f1de7f 275 if ((width < 8) && (NULL == _crc_table)) {
AnnaBridge 184:08ed48f1de7f 276 p_crc = (uint32_t)(p_crc << (8 - width));
AnnaBridge 184:08ed48f1de7f 277 }
AnnaBridge 188:bcfe06ba3d64 278 // Optimized algorithm for 32BitANSI does not need additional reflect_remainder
AnnaBridge 188:bcfe06ba3d64 279 if ((TABLE == _mode) && (POLY_32BIT_REV_ANSI == polynomial)) {
AnnaBridge 188:bcfe06ba3d64 280 *crc = (p_crc ^ _final_xor) & get_crc_mask();
AnnaBridge 188:bcfe06ba3d64 281 } else {
AnnaBridge 188:bcfe06ba3d64 282 *crc = (reflect_remainder(p_crc) ^ _final_xor) & get_crc_mask();
AnnaBridge 188:bcfe06ba3d64 283 }
AnnaBridge 188:bcfe06ba3d64 284 unlock();
AnnaBridge 184:08ed48f1de7f 285 return 0;
AnnaBridge 184:08ed48f1de7f 286 }
AnnaBridge 184:08ed48f1de7f 287
AnnaBridge 188:bcfe06ba3d64 288 /** Get the current CRC polynomial.
AnnaBridge 184:08ed48f1de7f 289 *
AnnaBridge 184:08ed48f1de7f 290 * @return Polynomial value
AnnaBridge 184:08ed48f1de7f 291 */
AnnaBridge 184:08ed48f1de7f 292 uint32_t get_polynomial(void) const
AnnaBridge 184:08ed48f1de7f 293 {
AnnaBridge 184:08ed48f1de7f 294 return polynomial;
AnnaBridge 184:08ed48f1de7f 295 }
AnnaBridge 184:08ed48f1de7f 296
AnnaBridge 184:08ed48f1de7f 297 /** Get the current CRC width
AnnaBridge 184:08ed48f1de7f 298 *
AnnaBridge 184:08ed48f1de7f 299 * @return CRC width
AnnaBridge 184:08ed48f1de7f 300 */
AnnaBridge 184:08ed48f1de7f 301 uint8_t get_width(void) const
AnnaBridge 184:08ed48f1de7f 302 {
AnnaBridge 184:08ed48f1de7f 303 return width;
AnnaBridge 184:08ed48f1de7f 304 }
AnnaBridge 184:08ed48f1de7f 305
AnnaBridge 189:f392fc9709a3 306 #if !defined(DOXYGEN_ONLY)
AnnaBridge 184:08ed48f1de7f 307 private:
AnnaBridge 184:08ed48f1de7f 308 uint32_t _initial_value;
AnnaBridge 184:08ed48f1de7f 309 uint32_t _final_xor;
AnnaBridge 184:08ed48f1de7f 310 bool _reflect_data;
AnnaBridge 184:08ed48f1de7f 311 bool _reflect_remainder;
AnnaBridge 184:08ed48f1de7f 312 uint32_t *_crc_table;
Anna Bridge 186:707f6e361f3e 313 CrcMode _mode;
AnnaBridge 184:08ed48f1de7f 314
AnnaBridge 188:bcfe06ba3d64 315 /** Acquire exclusive access to CRC hardware/software.
AnnaBridge 188:bcfe06ba3d64 316 */
AnnaBridge 189:f392fc9709a3 317 void lock()
AnnaBridge 188:bcfe06ba3d64 318 {
AnnaBridge 189:f392fc9709a3 319 #if DEVICE_CRC
AnnaBridge 188:bcfe06ba3d64 320 if (_mode == HARDWARE) {
AnnaBridge 188:bcfe06ba3d64 321 mbed_crc_mutex->lock();
AnnaBridge 188:bcfe06ba3d64 322 }
AnnaBridge 188:bcfe06ba3d64 323 #endif
AnnaBridge 188:bcfe06ba3d64 324 }
AnnaBridge 188:bcfe06ba3d64 325
AnnaBridge 188:bcfe06ba3d64 326 /** Release exclusive access to CRC hardware/software.
AnnaBridge 188:bcfe06ba3d64 327 */
AnnaBridge 188:bcfe06ba3d64 328 virtual void unlock()
AnnaBridge 188:bcfe06ba3d64 329 {
AnnaBridge 189:f392fc9709a3 330 #if DEVICE_CRC
AnnaBridge 188:bcfe06ba3d64 331 if (_mode == HARDWARE) {
AnnaBridge 188:bcfe06ba3d64 332 mbed_crc_mutex->unlock();
AnnaBridge 188:bcfe06ba3d64 333 }
AnnaBridge 188:bcfe06ba3d64 334 #endif
AnnaBridge 188:bcfe06ba3d64 335 }
AnnaBridge 188:bcfe06ba3d64 336
AnnaBridge 188:bcfe06ba3d64 337 /** Get the current CRC data size.
AnnaBridge 184:08ed48f1de7f 338 *
AnnaBridge 184:08ed48f1de7f 339 * @return CRC data size in bytes
AnnaBridge 184:08ed48f1de7f 340 */
AnnaBridge 184:08ed48f1de7f 341 uint8_t get_data_size(void) const
AnnaBridge 184:08ed48f1de7f 342 {
AnnaBridge 184:08ed48f1de7f 343 return (width <= 8 ? 1 : (width <= 16 ? 2 : 4));
AnnaBridge 184:08ed48f1de7f 344 }
AnnaBridge 184:08ed48f1de7f 345
AnnaBridge 188:bcfe06ba3d64 346 /** Get the top bit of current CRC.
AnnaBridge 184:08ed48f1de7f 347 *
AnnaBridge 184:08ed48f1de7f 348 * @return Top bit is set high for respective data width of current CRC
AnnaBridge 184:08ed48f1de7f 349 * Top bit for CRC width less then 8 bits will be set as 8th bit.
AnnaBridge 184:08ed48f1de7f 350 */
AnnaBridge 184:08ed48f1de7f 351 uint32_t get_top_bit(void) const
AnnaBridge 184:08ed48f1de7f 352 {
AnnaBridge 184:08ed48f1de7f 353 return (width < 8 ? (1u << 7) : (uint32_t)(1ul << (width - 1)));
AnnaBridge 184:08ed48f1de7f 354 }
AnnaBridge 184:08ed48f1de7f 355
AnnaBridge 188:bcfe06ba3d64 356 /** Get the CRC data mask.
AnnaBridge 184:08ed48f1de7f 357 *
AnnaBridge 184:08ed48f1de7f 358 * @return CRC data mask is generated based on current CRC width
AnnaBridge 184:08ed48f1de7f 359 */
AnnaBridge 184:08ed48f1de7f 360 uint32_t get_crc_mask(void) const
AnnaBridge 184:08ed48f1de7f 361 {
AnnaBridge 184:08ed48f1de7f 362 return (width < 8 ? ((1u << 8) - 1) : (uint32_t)((uint64_t)(1ull << width) - 1));
AnnaBridge 184:08ed48f1de7f 363 }
AnnaBridge 184:08ed48f1de7f 364
AnnaBridge 188:bcfe06ba3d64 365 /** Final value of CRC is reflected.
AnnaBridge 184:08ed48f1de7f 366 *
AnnaBridge 184:08ed48f1de7f 367 * @param data final crc value, which should be reflected
AnnaBridge 184:08ed48f1de7f 368 * @return Reflected CRC value
AnnaBridge 184:08ed48f1de7f 369 */
AnnaBridge 184:08ed48f1de7f 370 uint32_t reflect_remainder(uint32_t data) const
AnnaBridge 184:08ed48f1de7f 371 {
AnnaBridge 184:08ed48f1de7f 372 if (_reflect_remainder) {
AnnaBridge 184:08ed48f1de7f 373 uint32_t reflection = 0x0;
AnnaBridge 184:08ed48f1de7f 374 uint8_t const nBits = (width < 8 ? 8 : width);
AnnaBridge 184:08ed48f1de7f 375
AnnaBridge 184:08ed48f1de7f 376 for (uint8_t bit = 0; bit < nBits; ++bit) {
AnnaBridge 184:08ed48f1de7f 377 if (data & 0x01) {
AnnaBridge 184:08ed48f1de7f 378 reflection |= (1 << ((nBits - 1) - bit));
AnnaBridge 184:08ed48f1de7f 379 }
AnnaBridge 184:08ed48f1de7f 380 data = (data >> 1);
AnnaBridge 184:08ed48f1de7f 381 }
AnnaBridge 184:08ed48f1de7f 382 return (reflection);
AnnaBridge 184:08ed48f1de7f 383 } else {
AnnaBridge 184:08ed48f1de7f 384 return data;
AnnaBridge 184:08ed48f1de7f 385 }
AnnaBridge 184:08ed48f1de7f 386 }
AnnaBridge 184:08ed48f1de7f 387
AnnaBridge 188:bcfe06ba3d64 388 /** Data bytes are reflected.
AnnaBridge 184:08ed48f1de7f 389 *
AnnaBridge 184:08ed48f1de7f 390 * @param data value to be reflected
AnnaBridge 184:08ed48f1de7f 391 * @return Reflected data value
AnnaBridge 184:08ed48f1de7f 392 */
AnnaBridge 184:08ed48f1de7f 393 uint32_t reflect_bytes(uint32_t data) const
AnnaBridge 184:08ed48f1de7f 394 {
AnnaBridge 187:0387e8f68319 395 if (_reflect_data) {
AnnaBridge 184:08ed48f1de7f 396 uint32_t reflection = 0x0;
AnnaBridge 184:08ed48f1de7f 397
AnnaBridge 184:08ed48f1de7f 398 for (uint8_t bit = 0; bit < 8; ++bit) {
AnnaBridge 184:08ed48f1de7f 399 if (data & 0x01) {
AnnaBridge 184:08ed48f1de7f 400 reflection |= (1 << (7 - bit));
AnnaBridge 184:08ed48f1de7f 401 }
AnnaBridge 184:08ed48f1de7f 402 data = (data >> 1);
AnnaBridge 184:08ed48f1de7f 403 }
AnnaBridge 184:08ed48f1de7f 404 return (reflection);
AnnaBridge 184:08ed48f1de7f 405 } else {
AnnaBridge 184:08ed48f1de7f 406 return data;
AnnaBridge 184:08ed48f1de7f 407 }
AnnaBridge 184:08ed48f1de7f 408 }
AnnaBridge 184:08ed48f1de7f 409
AnnaBridge 188:bcfe06ba3d64 410 /** Bitwise CRC computation.
AnnaBridge 184:08ed48f1de7f 411 *
AnnaBridge 184:08ed48f1de7f 412 * @param buffer data buffer
AnnaBridge 184:08ed48f1de7f 413 * @param size size of the data
AnnaBridge 184:08ed48f1de7f 414 * @param crc CRC value is filled in, but the value is not the final
AnnaBridge 184:08ed48f1de7f 415 * @return 0 on success or a negative error code on failure
AnnaBridge 184:08ed48f1de7f 416 */
AnnaBridge 184:08ed48f1de7f 417 int32_t bitwise_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const
AnnaBridge 184:08ed48f1de7f 418 {
AnnaBridge 184:08ed48f1de7f 419 MBED_ASSERT(crc != NULL);
AnnaBridge 184:08ed48f1de7f 420
AnnaBridge 184:08ed48f1de7f 421 const uint8_t *data = static_cast<const uint8_t *>(buffer);
AnnaBridge 184:08ed48f1de7f 422 uint32_t p_crc = *crc;
AnnaBridge 184:08ed48f1de7f 423
AnnaBridge 184:08ed48f1de7f 424 if (width < 8) {
AnnaBridge 184:08ed48f1de7f 425 uint8_t data_byte;
AnnaBridge 184:08ed48f1de7f 426 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 184:08ed48f1de7f 427 data_byte = reflect_bytes(data[byte]);
AnnaBridge 184:08ed48f1de7f 428 for (uint8_t bit = 8; bit > 0; --bit) {
AnnaBridge 184:08ed48f1de7f 429 p_crc <<= 1;
AnnaBridge 187:0387e8f68319 430 if ((data_byte ^ p_crc) & get_top_bit()) {
AnnaBridge 184:08ed48f1de7f 431 p_crc ^= polynomial;
AnnaBridge 184:08ed48f1de7f 432 }
AnnaBridge 184:08ed48f1de7f 433 data_byte <<= 1;
AnnaBridge 184:08ed48f1de7f 434 }
AnnaBridge 184:08ed48f1de7f 435 }
AnnaBridge 184:08ed48f1de7f 436 } else {
AnnaBridge 184:08ed48f1de7f 437 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 184:08ed48f1de7f 438 p_crc ^= (reflect_bytes(data[byte]) << (width - 8));
AnnaBridge 184:08ed48f1de7f 439
AnnaBridge 184:08ed48f1de7f 440 // Perform modulo-2 division, a bit at a time
AnnaBridge 184:08ed48f1de7f 441 for (uint8_t bit = 8; bit > 0; --bit) {
AnnaBridge 184:08ed48f1de7f 442 if (p_crc & get_top_bit()) {
AnnaBridge 184:08ed48f1de7f 443 p_crc = (p_crc << 1) ^ polynomial;
AnnaBridge 184:08ed48f1de7f 444 } else {
AnnaBridge 184:08ed48f1de7f 445 p_crc = (p_crc << 1);
AnnaBridge 184:08ed48f1de7f 446 }
AnnaBridge 184:08ed48f1de7f 447 }
AnnaBridge 184:08ed48f1de7f 448 }
AnnaBridge 184:08ed48f1de7f 449 }
AnnaBridge 184:08ed48f1de7f 450 *crc = p_crc & get_crc_mask();
AnnaBridge 184:08ed48f1de7f 451 return 0;
AnnaBridge 184:08ed48f1de7f 452 }
AnnaBridge 184:08ed48f1de7f 453
AnnaBridge 188:bcfe06ba3d64 454 /** CRC computation using ROM tables.
AnnaBridge 187:0387e8f68319 455 *
AnnaBridge 187:0387e8f68319 456 * @param buffer data buffer
AnnaBridge 187:0387e8f68319 457 * @param size size of the data
AnnaBridge 187:0387e8f68319 458 * @param crc CRC value is filled in, but the value is not the final
AnnaBridge 187:0387e8f68319 459 * @return 0 on success or a negative error code on failure
AnnaBridge 187:0387e8f68319 460 */
AnnaBridge 184:08ed48f1de7f 461 int32_t table_compute_partial(const void *buffer, crc_data_size_t size, uint32_t *crc) const
AnnaBridge 184:08ed48f1de7f 462 {
AnnaBridge 184:08ed48f1de7f 463 MBED_ASSERT(crc != NULL);
AnnaBridge 184:08ed48f1de7f 464
AnnaBridge 184:08ed48f1de7f 465 const uint8_t *data = static_cast<const uint8_t *>(buffer);
AnnaBridge 184:08ed48f1de7f 466 uint32_t p_crc = *crc;
AnnaBridge 184:08ed48f1de7f 467 uint8_t data_byte = 0;
AnnaBridge 184:08ed48f1de7f 468
AnnaBridge 184:08ed48f1de7f 469 if (width <= 8) {
AnnaBridge 184:08ed48f1de7f 470 uint8_t *crc_table = (uint8_t *)_crc_table;
AnnaBridge 184:08ed48f1de7f 471 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 184:08ed48f1de7f 472 data_byte = reflect_bytes(data[byte]) ^ p_crc;
AnnaBridge 184:08ed48f1de7f 473 p_crc = crc_table[data_byte];
AnnaBridge 184:08ed48f1de7f 474 }
AnnaBridge 184:08ed48f1de7f 475 } else if (width <= 16) {
AnnaBridge 184:08ed48f1de7f 476 uint16_t *crc_table = (uint16_t *)_crc_table;
AnnaBridge 184:08ed48f1de7f 477 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 184:08ed48f1de7f 478 data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8));
AnnaBridge 184:08ed48f1de7f 479 p_crc = crc_table[data_byte] ^ (p_crc << 8);
AnnaBridge 184:08ed48f1de7f 480 }
AnnaBridge 184:08ed48f1de7f 481 } else {
AnnaBridge 184:08ed48f1de7f 482 uint32_t *crc_table = (uint32_t *)_crc_table;
AnnaBridge 188:bcfe06ba3d64 483 if (POLY_32BIT_REV_ANSI == polynomial) {
AnnaBridge 188:bcfe06ba3d64 484 for (crc_data_size_t i = 0; i < size; i++) {
AnnaBridge 188:bcfe06ba3d64 485 p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 0)) & 0xf];
AnnaBridge 188:bcfe06ba3d64 486 p_crc = (p_crc >> 4) ^ crc_table[(p_crc ^ (data[i] >> 4)) & 0xf];
AnnaBridge 188:bcfe06ba3d64 487 }
AnnaBridge 189:f392fc9709a3 488 } else {
AnnaBridge 188:bcfe06ba3d64 489 for (crc_data_size_t byte = 0; byte < size; byte++) {
AnnaBridge 188:bcfe06ba3d64 490 data_byte = reflect_bytes(data[byte]) ^ (p_crc >> (width - 8));
AnnaBridge 188:bcfe06ba3d64 491 p_crc = crc_table[data_byte] ^ (p_crc << 8);
AnnaBridge 188:bcfe06ba3d64 492 }
AnnaBridge 184:08ed48f1de7f 493 }
AnnaBridge 184:08ed48f1de7f 494 }
AnnaBridge 184:08ed48f1de7f 495 *crc = p_crc & get_crc_mask();
AnnaBridge 184:08ed48f1de7f 496 return 0;
AnnaBridge 184:08ed48f1de7f 497 }
AnnaBridge 184:08ed48f1de7f 498
AnnaBridge 188:bcfe06ba3d64 499 /** Constructor init called from all specialized cases of constructor.
AnnaBridge 189:f392fc9709a3 500 * Note: All constructor common code should be in this function.
AnnaBridge 184:08ed48f1de7f 501 */
Anna Bridge 186:707f6e361f3e 502 void mbed_crc_ctor(void)
AnnaBridge 184:08ed48f1de7f 503 {
AnnaBridge 184:08ed48f1de7f 504 MBED_STATIC_ASSERT(width <= 32, "Max 32-bit CRC supported");
Anna Bridge 186:707f6e361f3e 505
AnnaBridge 189:f392fc9709a3 506 #if DEVICE_CRC
AnnaBridge 188:bcfe06ba3d64 507 if (POLY_32BIT_REV_ANSI == polynomial) {
AnnaBridge 188:bcfe06ba3d64 508 _crc_table = (uint32_t *)Table_CRC_32bit_Rev_ANSI;
AnnaBridge 188:bcfe06ba3d64 509 _mode = TABLE;
AnnaBridge 188:bcfe06ba3d64 510 return;
AnnaBridge 188:bcfe06ba3d64 511 }
Anna Bridge 186:707f6e361f3e 512 crc_mbed_config_t config;
Anna Bridge 186:707f6e361f3e 513 config.polynomial = polynomial;
Anna Bridge 186:707f6e361f3e 514 config.width = width;
Anna Bridge 186:707f6e361f3e 515 config.initial_xor = _initial_value;
Anna Bridge 186:707f6e361f3e 516 config.final_xor = _final_xor;
Anna Bridge 186:707f6e361f3e 517 config.reflect_in = _reflect_data;
Anna Bridge 186:707f6e361f3e 518 config.reflect_out = _reflect_remainder;
Anna Bridge 186:707f6e361f3e 519
Anna Bridge 186:707f6e361f3e 520 if (hal_crc_is_supported(&config)) {
Anna Bridge 186:707f6e361f3e 521 _mode = HARDWARE;
AnnaBridge 188:bcfe06ba3d64 522 return;
Anna Bridge 186:707f6e361f3e 523 }
Anna Bridge 186:707f6e361f3e 524 #endif
AnnaBridge 188:bcfe06ba3d64 525
AnnaBridge 188:bcfe06ba3d64 526 switch (polynomial) {
AnnaBridge 188:bcfe06ba3d64 527 case POLY_32BIT_ANSI:
AnnaBridge 188:bcfe06ba3d64 528 _crc_table = (uint32_t *)Table_CRC_32bit_ANSI;
AnnaBridge 188:bcfe06ba3d64 529 break;
AnnaBridge 188:bcfe06ba3d64 530 case POLY_32BIT_REV_ANSI:
AnnaBridge 188:bcfe06ba3d64 531 _crc_table = (uint32_t *)Table_CRC_32bit_Rev_ANSI;
AnnaBridge 188:bcfe06ba3d64 532 break;
AnnaBridge 188:bcfe06ba3d64 533 case POLY_8BIT_CCITT:
AnnaBridge 188:bcfe06ba3d64 534 _crc_table = (uint32_t *)Table_CRC_8bit_CCITT;
AnnaBridge 188:bcfe06ba3d64 535 break;
AnnaBridge 188:bcfe06ba3d64 536 case POLY_7BIT_SD:
AnnaBridge 188:bcfe06ba3d64 537 _crc_table = (uint32_t *)Table_CRC_7Bit_SD;
AnnaBridge 188:bcfe06ba3d64 538 break;
AnnaBridge 188:bcfe06ba3d64 539 case POLY_16BIT_CCITT:
AnnaBridge 188:bcfe06ba3d64 540 _crc_table = (uint32_t *)Table_CRC_16bit_CCITT;
AnnaBridge 188:bcfe06ba3d64 541 break;
AnnaBridge 188:bcfe06ba3d64 542 case POLY_16BIT_IBM:
AnnaBridge 188:bcfe06ba3d64 543 _crc_table = (uint32_t *)Table_CRC_16bit_IBM;
AnnaBridge 188:bcfe06ba3d64 544 break;
AnnaBridge 188:bcfe06ba3d64 545 default:
AnnaBridge 188:bcfe06ba3d64 546 _crc_table = NULL;
AnnaBridge 188:bcfe06ba3d64 547 break;
AnnaBridge 188:bcfe06ba3d64 548 }
AnnaBridge 188:bcfe06ba3d64 549 _mode = (_crc_table != NULL) ? TABLE : BITWISE;
AnnaBridge 184:08ed48f1de7f 550 }
AnnaBridge 189:f392fc9709a3 551 #endif
AnnaBridge 184:08ed48f1de7f 552 };
AnnaBridge 184:08ed48f1de7f 553
AnnaBridge 184:08ed48f1de7f 554 #if defined ( __CC_ARM )
AnnaBridge 184:08ed48f1de7f 555 #elif defined ( __GNUC__ )
AnnaBridge 184:08ed48f1de7f 556 #pragma GCC diagnostic pop
AnnaBridge 187:0387e8f68319 557 #elif defined (__ICCARM__)
AnnaBridge 184:08ed48f1de7f 558 #endif
AnnaBridge 184:08ed48f1de7f 559
AnnaBridge 184:08ed48f1de7f 560 /** @}*/
AnnaBridge 184:08ed48f1de7f 561 } // namespace mbed
AnnaBridge 184:08ed48f1de7f 562
AnnaBridge 184:08ed48f1de7f 563 #endif