/* * 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 #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_ */