Diff: src/util.c

Revision:

9:9e247b9c9abf

diff -r 70fc373a5f46 -r 9e247b9c9abf src/util.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/util.c	Mon Jun 15 13:03:55 2020 +0000
@@ -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 "platform_drivers.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(&dividend, 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;
+}