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