58 lines
2.1 KiB
C
58 lines
2.1 KiB
C
/*
|
|
* Copyright (c) 2011 Broadcom Corporation
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
|
|
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
|
|
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
|
|
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
#ifndef __CORDIC_H_
|
|
#define __CORDIC_H_
|
|
|
|
#include <linux/types.h>
|
|
|
|
#define CORDIC_ANGLE_GEN 39797
|
|
#define CORDIC_PRECISION_SHIFT 16
|
|
#define CORDIC_NUM_ITER (CORDIC_PRECISION_SHIFT + 2)
|
|
|
|
#define CORDIC_FIXED(X) ((s32)((X) << CORDIC_PRECISION_SHIFT))
|
|
#define CORDIC_FLOAT(X) (((X) >= 0) \
|
|
? ((((X) >> (CORDIC_PRECISION_SHIFT - 1)) + 1) >> 1) \
|
|
: -((((-(X)) >> (CORDIC_PRECISION_SHIFT - 1)) + 1) >> 1))
|
|
|
|
/**
|
|
* struct cordic_iq - i/q coordinate.
|
|
*
|
|
* @i: real part of coordinate (in phase).
|
|
* @q: imaginary part of coordinate (quadrature).
|
|
*/
|
|
struct cordic_iq {
|
|
s32 i;
|
|
s32 q;
|
|
};
|
|
|
|
/**
|
|
* cordic_calc_iq() - calculates the i/q coordinate for given angle.
|
|
*
|
|
* @theta: angle in degrees for which i/q coordinate is to be calculated.
|
|
* @coord: function output parameter holding the i/q coordinate.
|
|
*
|
|
* The function calculates the i/q coordinate for a given angle using the
|
|
* CORDIC algorithm. The coordinate consists of a real (i) and an
|
|
* imaginary (q) part. The real part is essentially the cosine of the
|
|
* angle and the imaginary part is the sine of the angle. The returned
|
|
* values are scaled by 2^16 for precision. The range for theta is
|
|
* for -180 degrees to +180 degrees. Passed values outside this range are
|
|
* converted before doing the actual calculation.
|
|
*/
|
|
struct cordic_iq cordic_calc_iq(s32 theta);
|
|
|
|
#endif /* __CORDIC_H_ */
|