110f8113eSArend van Spriel /* 210f8113eSArend van Spriel * Copyright (c) 2011 Broadcom Corporation 310f8113eSArend van Spriel * 410f8113eSArend van Spriel * Permission to use, copy, modify, and/or distribute this software for any 510f8113eSArend van Spriel * purpose with or without fee is hereby granted, provided that the above 610f8113eSArend van Spriel * copyright notice and this permission notice appear in all copies. 710f8113eSArend van Spriel * 810f8113eSArend van Spriel * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 910f8113eSArend van Spriel * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 1010f8113eSArend van Spriel * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 1110f8113eSArend van Spriel * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 1210f8113eSArend van Spriel * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 1310f8113eSArend van Spriel * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 1410f8113eSArend van Spriel * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 1510f8113eSArend van Spriel */ 1610f8113eSArend van Spriel #ifndef __CORDIC_H_ 1710f8113eSArend van Spriel #define __CORDIC_H_ 1810f8113eSArend van Spriel 1910f8113eSArend van Spriel #include <linux/types.h> 2010f8113eSArend van Spriel 21*58d81d64SPriit Laes #define CORDIC_ANGLE_GEN 39797 22*58d81d64SPriit Laes #define CORDIC_PRECISION_SHIFT 16 23*58d81d64SPriit Laes #define CORDIC_NUM_ITER (CORDIC_PRECISION_SHIFT + 2) 24*58d81d64SPriit Laes 25*58d81d64SPriit Laes #define CORDIC_FIXED(X) ((s32)((X) << CORDIC_PRECISION_SHIFT)) 26*58d81d64SPriit Laes #define CORDIC_FLOAT(X) (((X) >= 0) \ 27*58d81d64SPriit Laes ? ((((X) >> (CORDIC_PRECISION_SHIFT - 1)) + 1) >> 1) \ 28*58d81d64SPriit Laes : -((((-(X)) >> (CORDIC_PRECISION_SHIFT - 1)) + 1) >> 1)) 29*58d81d64SPriit Laes 3010f8113eSArend van Spriel /** 3110f8113eSArend van Spriel * struct cordic_iq - i/q coordinate. 3210f8113eSArend van Spriel * 3310f8113eSArend van Spriel * @i: real part of coordinate (in phase). 3410f8113eSArend van Spriel * @q: imaginary part of coordinate (quadrature). 3510f8113eSArend van Spriel */ 3610f8113eSArend van Spriel struct cordic_iq { 3710f8113eSArend van Spriel s32 i; 3810f8113eSArend van Spriel s32 q; 3910f8113eSArend van Spriel }; 4010f8113eSArend van Spriel 4110f8113eSArend van Spriel /** 4210f8113eSArend van Spriel * cordic_calc_iq() - calculates the i/q coordinate for given angle. 4310f8113eSArend van Spriel * 4410f8113eSArend van Spriel * @theta: angle in degrees for which i/q coordinate is to be calculated. 4510f8113eSArend van Spriel * @coord: function output parameter holding the i/q coordinate. 4610f8113eSArend van Spriel * 47c6208469SMichael Witten * The function calculates the i/q coordinate for a given angle using the 480314322dSMichael Witten * CORDIC algorithm. The coordinate consists of a real (i) and an 4910f8113eSArend van Spriel * imaginary (q) part. The real part is essentially the cosine of the 5010f8113eSArend van Spriel * angle and the imaginary part is the sine of the angle. The returned 5110f8113eSArend van Spriel * values are scaled by 2^16 for precision. The range for theta is 5210f8113eSArend van Spriel * for -180 degrees to +180 degrees. Passed values outside this range are 5310f8113eSArend van Spriel * converted before doing the actual calculation. 5410f8113eSArend van Spriel */ 5510f8113eSArend van Spriel struct cordic_iq cordic_calc_iq(s32 theta); 5610f8113eSArend van Spriel 5710f8113eSArend van Spriel #endif /* __CORDIC_H_ */ 58