1*4882a593Smuzhiyun /* 2*4882a593Smuzhiyun * Copyright (c) 2011 Broadcom Corporation 3*4882a593Smuzhiyun * 4*4882a593Smuzhiyun * Permission to use, copy, modify, and/or distribute this software for any 5*4882a593Smuzhiyun * purpose with or without fee is hereby granted, provided that the above 6*4882a593Smuzhiyun * copyright notice and this permission notice appear in all copies. 7*4882a593Smuzhiyun * 8*4882a593Smuzhiyun * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9*4882a593Smuzhiyun * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10*4882a593Smuzhiyun * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 11*4882a593Smuzhiyun * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12*4882a593Smuzhiyun * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 13*4882a593Smuzhiyun * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 14*4882a593Smuzhiyun * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15*4882a593Smuzhiyun */ 16*4882a593Smuzhiyun #ifndef __CORDIC_H_ 17*4882a593Smuzhiyun #define __CORDIC_H_ 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun #include <linux/types.h> 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun #define CORDIC_ANGLE_GEN 39797 22*4882a593Smuzhiyun #define CORDIC_PRECISION_SHIFT 16 23*4882a593Smuzhiyun #define CORDIC_NUM_ITER (CORDIC_PRECISION_SHIFT + 2) 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun #define CORDIC_FIXED(X) ((s32)((X) << CORDIC_PRECISION_SHIFT)) 26*4882a593Smuzhiyun #define CORDIC_FLOAT(X) (((X) >= 0) \ 27*4882a593Smuzhiyun ? ((((X) >> (CORDIC_PRECISION_SHIFT - 1)) + 1) >> 1) \ 28*4882a593Smuzhiyun : -((((-(X)) >> (CORDIC_PRECISION_SHIFT - 1)) + 1) >> 1)) 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun /** 31*4882a593Smuzhiyun * struct cordic_iq - i/q coordinate. 32*4882a593Smuzhiyun * 33*4882a593Smuzhiyun * @i: real part of coordinate (in phase). 34*4882a593Smuzhiyun * @q: imaginary part of coordinate (quadrature). 35*4882a593Smuzhiyun */ 36*4882a593Smuzhiyun struct cordic_iq { 37*4882a593Smuzhiyun s32 i; 38*4882a593Smuzhiyun s32 q; 39*4882a593Smuzhiyun }; 40*4882a593Smuzhiyun 41*4882a593Smuzhiyun /** 42*4882a593Smuzhiyun * cordic_calc_iq() - calculates the i/q coordinate for given angle. 43*4882a593Smuzhiyun * 44*4882a593Smuzhiyun * @theta: angle in degrees for which i/q coordinate is to be calculated. 45*4882a593Smuzhiyun * @coord: function output parameter holding the i/q coordinate. 46*4882a593Smuzhiyun * 47*4882a593Smuzhiyun * The function calculates the i/q coordinate for a given angle using the 48*4882a593Smuzhiyun * CORDIC algorithm. The coordinate consists of a real (i) and an 49*4882a593Smuzhiyun * imaginary (q) part. The real part is essentially the cosine of the 50*4882a593Smuzhiyun * angle and the imaginary part is the sine of the angle. The returned 51*4882a593Smuzhiyun * values are scaled by 2^16 for precision. The range for theta is 52*4882a593Smuzhiyun * for -180 degrees to +180 degrees. Passed values outside this range are 53*4882a593Smuzhiyun * converted before doing the actual calculation. 54*4882a593Smuzhiyun */ 55*4882a593Smuzhiyun struct cordic_iq cordic_calc_iq(s32 theta); 56*4882a593Smuzhiyun 57*4882a593Smuzhiyun #endif /* __CORDIC_H_ */ 58