Pratyush Mallick
/
nano_dac
this is testing
Diff: noos_mbed/util/util.c
- Revision:
- 0:e8a1ba50c46b
diff -r 000000000000 -r e8a1ba50c46b noos_mbed/util/util.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/noos_mbed/util/util.c Thu Jan 14 19:12:57 2021 +0530 @@ -0,0 +1,264 @@ +/***************************************************************************//** + * @file util.c + * @brief Implementation of utility functions. + * @author DBogdan (dragos.bogdan@analog.com) +******************************************************************************** + * Copyright 2018(c) Analog Devices, Inc. + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * - Neither the name of Analog Devices, Inc. nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * - The use of this software may or may not infringe the patent rights + * of one or more patent holders. This license does not release you + * from the requirement that you obtain separate licenses from these + * patent holders to use this software. + * - Use of the software either in source or binary form, must be run + * on or directly connected to an Analog Devices Inc. component. + * + * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*******************************************************************************/ + +/******************************************************************************/ +/***************************** Include Files **********************************/ +/******************************************************************************/ +#include <string.h> +#include <stdlib.h> +#include "util.h" +#include "errno.h" +/******************************************************************************/ +/************************** Functions Implementation **************************/ +/******************************************************************************/ + +/** + * Find first set bit in word. + */ +uint32_t find_first_set_bit(uint32_t word) +{ + uint32_t first_set_bit = 0; + + while (word) { + if (word & 0x1) + return first_set_bit; + word >>= 1; + first_set_bit ++; + } + + return 32; +} + +/** + * Find last set bit in word. + */ +uint32_t find_last_set_bit(uint32_t word) +{ + uint32_t bit = 0; + uint32_t last_set_bit = 32; + + while (word) { + if (word & 0x1) + last_set_bit = bit; + word >>= 1; + bit ++; + } + + return last_set_bit; +} + +/** + * Locate the closest element in an array. + */ +uint32_t find_closest(int32_t val, + const int32_t *array, + uint32_t size) +{ + int32_t diff = abs(array[0] - val); + uint32_t ret = 0; + uint32_t i; + + for (i = 1; i < size; i++) { + if (abs(array[i] - val) < diff) { + diff = abs(array[i] - val); + ret = i; + } + } + + return ret; +} + +/** + * Shift the value and apply the specified mask. + */ +uint32_t field_prep(uint32_t mask, uint32_t val) +{ + return (val << find_first_set_bit(mask)) & mask; +} + +/** + * Get a field specified by a mask from a word. + */ +uint32_t field_get(uint32_t mask, uint32_t word) +{ + return (word & mask) >> find_first_set_bit(mask); +} + +/** + * Log base 2 of the given number. + */ +int32_t log_base_2(uint32_t x) +{ + return find_last_set_bit(x); +} + +/** + * Find greatest common divisor of the given two numbers. + */ +uint32_t greatest_common_divisor(uint32_t a, + uint32_t b) +{ + uint32_t div; + uint32_t common_div = 1; + + if ((a == 0) || (b == 0)) + return max(a, b); + + for (div = 1; (div <= a) && (div <= b); div++) + if (!(a % div) && !(b % div)) + common_div = div; + + return common_div; +} + +/** + * Calculate best rational approximation for a given fraction. + */ +void rational_best_approximation(uint32_t given_numerator, + uint32_t given_denominator, + uint32_t max_numerator, + uint32_t max_denominator, + uint32_t *best_numerator, + uint32_t *best_denominator) +{ + uint32_t gcd; + + gcd = greatest_common_divisor(given_numerator, given_denominator); + + *best_numerator = given_numerator / gcd; + *best_denominator = given_denominator / gcd; + + if ((*best_numerator > max_numerator) || + (*best_denominator > max_denominator)) { + *best_numerator = 0; + *best_denominator = 0; + } +} + +/** + * Calculate the number of set bits. + */ +uint32_t hweight8(uint32_t word) +{ + uint32_t count = 0; + + while (word) { + if (word & 0x1) + count++; + word >>= 1; + } + + return count; +} + +/** + * Calculate the quotient and the remainder of an integer division. + */ +uint64_t do_div(uint64_t* n, + uint64_t base) +{ + uint64_t mod = 0; + + mod = *n % base; + *n = *n / base; + + return mod; +} + +/** + * Unsigned 64bit divide with 64bit divisor and remainder + */ +uint64_t div64_u64_rem(uint64_t dividend, uint64_t divisor, uint64_t *remainder) +{ + *remainder = dividend % divisor; + + return dividend / divisor; +} + +/** + * Unsigned 64bit divide with 32bit divisor with remainder + */ +uint64_t div_u64_rem(uint64_t dividend, uint32_t divisor, uint32_t *remainder) +{ + *remainder = do_div(÷nd, divisor); + + return dividend; +} + +/** + * Unsigned 64bit divide with 32bit divisor + */ +uint64_t div_u64(uint64_t dividend, uint32_t divisor) +{ + uint32_t remainder; + + return div_u64_rem(dividend, divisor, &remainder); +} + +/** + * Converts from string to int32_t + * @param *str + * @return int32_t + */ +int32_t str_to_int32(const char *str) +{ + char *end; + int32_t value = strtol(str, &end, 0); + + if (end == str) + return -EINVAL; + else + return value; +} + +/** + * Converts from string to uint32_t + * @param *str + * @return uint32_t + */ +uint32_t srt_to_uint32(const char *str) +{ + char *end; + uint32_t value = strtoul(str, &end, 0); + + if (end == str) + return -EINVAL; + else + return value; +}