Pratyush Mallick / Mbed OS nano_dac

this is testing

noos_mbed/util/util.c@0:e8a1ba50c46b, 2021-01-14 (annotated)

Committer:
pmallick
Date:
Thu Jan 14 19:12:57 2021 +0530
Revision:
0:e8a1ba50c46b
this is testing

Who changed what in which revision?

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pmallick 0:e8a1ba50c46b 1 /***************************************************************************//**
pmallick 0:e8a1ba50c46b 2 * @file util.c
pmallick 0:e8a1ba50c46b 3 * @brief Implementation of utility functions.
pmallick 0:e8a1ba50c46b 4 * @author DBogdan (dragos.bogdan@analog.com)
pmallick 0:e8a1ba50c46b 5 ********************************************************************************
pmallick 0:e8a1ba50c46b 6 * Copyright 2018(c) Analog Devices, Inc.
pmallick 0:e8a1ba50c46b 7 *
pmallick 0:e8a1ba50c46b 8 * All rights reserved.
pmallick 0:e8a1ba50c46b 9 *
pmallick 0:e8a1ba50c46b 10 * Redistribution and use in source and binary forms, with or without
pmallick 0:e8a1ba50c46b 11 * modification, are permitted provided that the following conditions are met:
pmallick 0:e8a1ba50c46b 12 * - Redistributions of source code must retain the above copyright
pmallick 0:e8a1ba50c46b 13 * notice, this list of conditions and the following disclaimer.
pmallick 0:e8a1ba50c46b 14 * - Redistributions in binary form must reproduce the above copyright
pmallick 0:e8a1ba50c46b 15 * notice, this list of conditions and the following disclaimer in
pmallick 0:e8a1ba50c46b 16 * the documentation and/or other materials provided with the
pmallick 0:e8a1ba50c46b 17 * distribution.
pmallick 0:e8a1ba50c46b 18 * - Neither the name of Analog Devices, Inc. nor the names of its
pmallick 0:e8a1ba50c46b 19 * contributors may be used to endorse or promote products derived
pmallick 0:e8a1ba50c46b 20 * from this software without specific prior written permission.
pmallick 0:e8a1ba50c46b 21 * - The use of this software may or may not infringe the patent rights
pmallick 0:e8a1ba50c46b 22 * of one or more patent holders. This license does not release you
pmallick 0:e8a1ba50c46b 23 * from the requirement that you obtain separate licenses from these
pmallick 0:e8a1ba50c46b 24 * patent holders to use this software.
pmallick 0:e8a1ba50c46b 25 * - Use of the software either in source or binary form, must be run
pmallick 0:e8a1ba50c46b 26 * on or directly connected to an Analog Devices Inc. component.
pmallick 0:e8a1ba50c46b 27 *
pmallick 0:e8a1ba50c46b 28 * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
pmallick 0:e8a1ba50c46b 29 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
pmallick 0:e8a1ba50c46b 30 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
pmallick 0:e8a1ba50c46b 31 * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
pmallick 0:e8a1ba50c46b 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
pmallick 0:e8a1ba50c46b 33 * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
pmallick 0:e8a1ba50c46b 34 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
pmallick 0:e8a1ba50c46b 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
pmallick 0:e8a1ba50c46b 36 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
pmallick 0:e8a1ba50c46b 37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
pmallick 0:e8a1ba50c46b 38 *******************************************************************************/
pmallick 0:e8a1ba50c46b 39
pmallick 0:e8a1ba50c46b 40 /******************************************************************************/
pmallick 0:e8a1ba50c46b 41 /***************************** Include Files **********************************/
pmallick 0:e8a1ba50c46b 42 /******************************************************************************/
pmallick 0:e8a1ba50c46b 43 #include <string.h>
pmallick 0:e8a1ba50c46b 44 #include <stdlib.h>
pmallick 0:e8a1ba50c46b 45 #include "util.h"
pmallick 0:e8a1ba50c46b 46 #include "errno.h"
pmallick 0:e8a1ba50c46b 47 /******************************************************************************/
pmallick 0:e8a1ba50c46b 48 /************************** Functions Implementation **************************/
pmallick 0:e8a1ba50c46b 49 /******************************************************************************/
pmallick 0:e8a1ba50c46b 50
pmallick 0:e8a1ba50c46b 51 /**
pmallick 0:e8a1ba50c46b 52 * Find first set bit in word.
pmallick 0:e8a1ba50c46b 53 */
pmallick 0:e8a1ba50c46b 54 uint32_t find_first_set_bit(uint32_t word)
pmallick 0:e8a1ba50c46b 55 {
pmallick 0:e8a1ba50c46b 56 uint32_t first_set_bit = 0;
pmallick 0:e8a1ba50c46b 57
pmallick 0:e8a1ba50c46b 58 while (word) {
pmallick 0:e8a1ba50c46b 59 if (word & 0x1)
pmallick 0:e8a1ba50c46b 60 return first_set_bit;
pmallick 0:e8a1ba50c46b 61 word >>= 1;
pmallick 0:e8a1ba50c46b 62 first_set_bit ++;
pmallick 0:e8a1ba50c46b 63 }
pmallick 0:e8a1ba50c46b 64
pmallick 0:e8a1ba50c46b 65 return 32;
pmallick 0:e8a1ba50c46b 66 }
pmallick 0:e8a1ba50c46b 67
pmallick 0:e8a1ba50c46b 68 /**
pmallick 0:e8a1ba50c46b 69 * Find last set bit in word.
pmallick 0:e8a1ba50c46b 70 */
pmallick 0:e8a1ba50c46b 71 uint32_t find_last_set_bit(uint32_t word)
pmallick 0:e8a1ba50c46b 72 {
pmallick 0:e8a1ba50c46b 73 uint32_t bit = 0;
pmallick 0:e8a1ba50c46b 74 uint32_t last_set_bit = 32;
pmallick 0:e8a1ba50c46b 75
pmallick 0:e8a1ba50c46b 76 while (word) {
pmallick 0:e8a1ba50c46b 77 if (word & 0x1)
pmallick 0:e8a1ba50c46b 78 last_set_bit = bit;
pmallick 0:e8a1ba50c46b 79 word >>= 1;
pmallick 0:e8a1ba50c46b 80 bit ++;
pmallick 0:e8a1ba50c46b 81 }
pmallick 0:e8a1ba50c46b 82
pmallick 0:e8a1ba50c46b 83 return last_set_bit;
pmallick 0:e8a1ba50c46b 84 }
pmallick 0:e8a1ba50c46b 85
pmallick 0:e8a1ba50c46b 86 /**
pmallick 0:e8a1ba50c46b 87 * Locate the closest element in an array.
pmallick 0:e8a1ba50c46b 88 */
pmallick 0:e8a1ba50c46b 89 uint32_t find_closest(int32_t val,
pmallick 0:e8a1ba50c46b 90 const int32_t *array,
pmallick 0:e8a1ba50c46b 91 uint32_t size)
pmallick 0:e8a1ba50c46b 92 {
pmallick 0:e8a1ba50c46b 93 int32_t diff = abs(array[0] - val);
pmallick 0:e8a1ba50c46b 94 uint32_t ret = 0;
pmallick 0:e8a1ba50c46b 95 uint32_t i;
pmallick 0:e8a1ba50c46b 96
pmallick 0:e8a1ba50c46b 97 for (i = 1; i < size; i++) {
pmallick 0:e8a1ba50c46b 98 if (abs(array[i] - val) < diff) {
pmallick 0:e8a1ba50c46b 99 diff = abs(array[i] - val);
pmallick 0:e8a1ba50c46b 100 ret = i;
pmallick 0:e8a1ba50c46b 101 }
pmallick 0:e8a1ba50c46b 102 }
pmallick 0:e8a1ba50c46b 103
pmallick 0:e8a1ba50c46b 104 return ret;
pmallick 0:e8a1ba50c46b 105 }
pmallick 0:e8a1ba50c46b 106
pmallick 0:e8a1ba50c46b 107 /**
pmallick 0:e8a1ba50c46b 108 * Shift the value and apply the specified mask.
pmallick 0:e8a1ba50c46b 109 */
pmallick 0:e8a1ba50c46b 110 uint32_t field_prep(uint32_t mask, uint32_t val)
pmallick 0:e8a1ba50c46b 111 {
pmallick 0:e8a1ba50c46b 112 return (val << find_first_set_bit(mask)) & mask;
pmallick 0:e8a1ba50c46b 113 }
pmallick 0:e8a1ba50c46b 114
pmallick 0:e8a1ba50c46b 115 /**
pmallick 0:e8a1ba50c46b 116 * Get a field specified by a mask from a word.
pmallick 0:e8a1ba50c46b 117 */
pmallick 0:e8a1ba50c46b 118 uint32_t field_get(uint32_t mask, uint32_t word)
pmallick 0:e8a1ba50c46b 119 {
pmallick 0:e8a1ba50c46b 120 return (word & mask) >> find_first_set_bit(mask);
pmallick 0:e8a1ba50c46b 121 }
pmallick 0:e8a1ba50c46b 122
pmallick 0:e8a1ba50c46b 123 /**
pmallick 0:e8a1ba50c46b 124 * Log base 2 of the given number.
pmallick 0:e8a1ba50c46b 125 */
pmallick 0:e8a1ba50c46b 126 int32_t log_base_2(uint32_t x)
pmallick 0:e8a1ba50c46b 127 {
pmallick 0:e8a1ba50c46b 128 return find_last_set_bit(x);
pmallick 0:e8a1ba50c46b 129 }
pmallick 0:e8a1ba50c46b 130
pmallick 0:e8a1ba50c46b 131 /**
pmallick 0:e8a1ba50c46b 132 * Find greatest common divisor of the given two numbers.
pmallick 0:e8a1ba50c46b 133 */
pmallick 0:e8a1ba50c46b 134 uint32_t greatest_common_divisor(uint32_t a,
pmallick 0:e8a1ba50c46b 135 uint32_t b)
pmallick 0:e8a1ba50c46b 136 {
pmallick 0:e8a1ba50c46b 137 uint32_t div;
pmallick 0:e8a1ba50c46b 138 uint32_t common_div = 1;
pmallick 0:e8a1ba50c46b 139
pmallick 0:e8a1ba50c46b 140 if ((a == 0) || (b == 0))
pmallick 0:e8a1ba50c46b 141 return max(a, b);
pmallick 0:e8a1ba50c46b 142
pmallick 0:e8a1ba50c46b 143 for (div = 1; (div <= a) && (div <= b); div++)
pmallick 0:e8a1ba50c46b 144 if (!(a % div) && !(b % div))
pmallick 0:e8a1ba50c46b 145 common_div = div;
pmallick 0:e8a1ba50c46b 146
pmallick 0:e8a1ba50c46b 147 return common_div;
pmallick 0:e8a1ba50c46b 148 }
pmallick 0:e8a1ba50c46b 149
pmallick 0:e8a1ba50c46b 150 /**
pmallick 0:e8a1ba50c46b 151 * Calculate best rational approximation for a given fraction.
pmallick 0:e8a1ba50c46b 152 */
pmallick 0:e8a1ba50c46b 153 void rational_best_approximation(uint32_t given_numerator,
pmallick 0:e8a1ba50c46b 154 uint32_t given_denominator,
pmallick 0:e8a1ba50c46b 155 uint32_t max_numerator,
pmallick 0:e8a1ba50c46b 156 uint32_t max_denominator,
pmallick 0:e8a1ba50c46b 157 uint32_t *best_numerator,
pmallick 0:e8a1ba50c46b 158 uint32_t *best_denominator)
pmallick 0:e8a1ba50c46b 159 {
pmallick 0:e8a1ba50c46b 160 uint32_t gcd;
pmallick 0:e8a1ba50c46b 161
pmallick 0:e8a1ba50c46b 162 gcd = greatest_common_divisor(given_numerator, given_denominator);
pmallick 0:e8a1ba50c46b 163
pmallick 0:e8a1ba50c46b 164 *best_numerator = given_numerator / gcd;
pmallick 0:e8a1ba50c46b 165 *best_denominator = given_denominator / gcd;
pmallick 0:e8a1ba50c46b 166
pmallick 0:e8a1ba50c46b 167 if ((*best_numerator > max_numerator) ||
pmallick 0:e8a1ba50c46b 168 (*best_denominator > max_denominator)) {
pmallick 0:e8a1ba50c46b 169 *best_numerator = 0;
pmallick 0:e8a1ba50c46b 170 *best_denominator = 0;
pmallick 0:e8a1ba50c46b 171 }
pmallick 0:e8a1ba50c46b 172 }
pmallick 0:e8a1ba50c46b 173
pmallick 0:e8a1ba50c46b 174 /**
pmallick 0:e8a1ba50c46b 175 * Calculate the number of set bits.
pmallick 0:e8a1ba50c46b 176 */
pmallick 0:e8a1ba50c46b 177 uint32_t hweight8(uint32_t word)
pmallick 0:e8a1ba50c46b 178 {
pmallick 0:e8a1ba50c46b 179 uint32_t count = 0;
pmallick 0:e8a1ba50c46b 180
pmallick 0:e8a1ba50c46b 181 while (word) {
pmallick 0:e8a1ba50c46b 182 if (word & 0x1)
pmallick 0:e8a1ba50c46b 183 count++;
pmallick 0:e8a1ba50c46b 184 word >>= 1;
pmallick 0:e8a1ba50c46b 185 }
pmallick 0:e8a1ba50c46b 186
pmallick 0:e8a1ba50c46b 187 return count;
pmallick 0:e8a1ba50c46b 188 }
pmallick 0:e8a1ba50c46b 189
pmallick 0:e8a1ba50c46b 190 /**
pmallick 0:e8a1ba50c46b 191 * Calculate the quotient and the remainder of an integer division.
pmallick 0:e8a1ba50c46b 192 */
pmallick 0:e8a1ba50c46b 193 uint64_t do_div(uint64_t* n,
pmallick 0:e8a1ba50c46b 194 uint64_t base)
pmallick 0:e8a1ba50c46b 195 {
pmallick 0:e8a1ba50c46b 196 uint64_t mod = 0;
pmallick 0:e8a1ba50c46b 197
pmallick 0:e8a1ba50c46b 198 mod = *n % base;
pmallick 0:e8a1ba50c46b 199 *n = *n / base;
pmallick 0:e8a1ba50c46b 200
pmallick 0:e8a1ba50c46b 201 return mod;
pmallick 0:e8a1ba50c46b 202 }
pmallick 0:e8a1ba50c46b 203
pmallick 0:e8a1ba50c46b 204 /**
pmallick 0:e8a1ba50c46b 205 * Unsigned 64bit divide with 64bit divisor and remainder
pmallick 0:e8a1ba50c46b 206 */
pmallick 0:e8a1ba50c46b 207 uint64_t div64_u64_rem(uint64_t dividend, uint64_t divisor, uint64_t *remainder)
pmallick 0:e8a1ba50c46b 208 {
pmallick 0:e8a1ba50c46b 209 *remainder = dividend % divisor;
pmallick 0:e8a1ba50c46b 210
pmallick 0:e8a1ba50c46b 211 return dividend / divisor;
pmallick 0:e8a1ba50c46b 212 }
pmallick 0:e8a1ba50c46b 213
pmallick 0:e8a1ba50c46b 214 /**
pmallick 0:e8a1ba50c46b 215 * Unsigned 64bit divide with 32bit divisor with remainder
pmallick 0:e8a1ba50c46b 216 */
pmallick 0:e8a1ba50c46b 217 uint64_t div_u64_rem(uint64_t dividend, uint32_t divisor, uint32_t *remainder)
pmallick 0:e8a1ba50c46b 218 {
pmallick 0:e8a1ba50c46b 219 *remainder = do_div(&dividend, divisor);
pmallick 0:e8a1ba50c46b 220
pmallick 0:e8a1ba50c46b 221 return dividend;
pmallick 0:e8a1ba50c46b 222 }
pmallick 0:e8a1ba50c46b 223
pmallick 0:e8a1ba50c46b 224 /**
pmallick 0:e8a1ba50c46b 225 * Unsigned 64bit divide with 32bit divisor
pmallick 0:e8a1ba50c46b 226 */
pmallick 0:e8a1ba50c46b 227 uint64_t div_u64(uint64_t dividend, uint32_t divisor)
pmallick 0:e8a1ba50c46b 228 {
pmallick 0:e8a1ba50c46b 229 uint32_t remainder;
pmallick 0:e8a1ba50c46b 230
pmallick 0:e8a1ba50c46b 231 return div_u64_rem(dividend, divisor, &remainder);
pmallick 0:e8a1ba50c46b 232 }
pmallick 0:e8a1ba50c46b 233
pmallick 0:e8a1ba50c46b 234 /**
pmallick 0:e8a1ba50c46b 235 * Converts from string to int32_t
pmallick 0:e8a1ba50c46b 236 * @param *str
pmallick 0:e8a1ba50c46b 237 * @return int32_t
pmallick 0:e8a1ba50c46b 238 */
pmallick 0:e8a1ba50c46b 239 int32_t str_to_int32(const char *str)
pmallick 0:e8a1ba50c46b 240 {
pmallick 0:e8a1ba50c46b 241 char *end;
pmallick 0:e8a1ba50c46b 242 int32_t value = strtol(str, &end, 0);
pmallick 0:e8a1ba50c46b 243
pmallick 0:e8a1ba50c46b 244 if (end == str)
pmallick 0:e8a1ba50c46b 245 return -EINVAL;
pmallick 0:e8a1ba50c46b 246 else
pmallick 0:e8a1ba50c46b 247 return value;
pmallick 0:e8a1ba50c46b 248 }
pmallick 0:e8a1ba50c46b 249
pmallick 0:e8a1ba50c46b 250 /**
pmallick 0:e8a1ba50c46b 251 * Converts from string to uint32_t
pmallick 0:e8a1ba50c46b 252 * @param *str
pmallick 0:e8a1ba50c46b 253 * @return uint32_t
pmallick 0:e8a1ba50c46b 254 */
pmallick 0:e8a1ba50c46b 255 uint32_t srt_to_uint32(const char *str)
pmallick 0:e8a1ba50c46b 256 {
pmallick 0:e8a1ba50c46b 257 char *end;
pmallick 0:e8a1ba50c46b 258 uint32_t value = strtoul(str, &end, 0);
pmallick 0:e8a1ba50c46b 259
pmallick 0:e8a1ba50c46b 260 if (end == str)
pmallick 0:e8a1ba50c46b 261 return -EINVAL;
pmallick 0:e8a1ba50c46b 262 else
pmallick 0:e8a1ba50c46b 263 return value;
pmallick 0:e8a1ba50c46b 264 }