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Arend van Spriel10f81132011-05-31 11:22:16 +02001/*
2 * Copyright (c) 2011 Broadcom Corporation
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
11 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
13 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
14 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16#ifndef __CORDIC_H_
17#define __CORDIC_H_
18
19#include <linux/types.h>
20
21/**
22 * struct cordic_iq - i/q coordinate.
23 *
24 * @i: real part of coordinate (in phase).
25 * @q: imaginary part of coordinate (quadrature).
26 */
27struct cordic_iq {
28 s32 i;
29 s32 q;
30};
31
32/**
33 * cordic_calc_iq() - calculates the i/q coordinate for given angle.
34 *
35 * @theta: angle in degrees for which i/q coordinate is to be calculated.
36 * @coord: function output parameter holding the i/q coordinate.
37 *
38 * The function calculates the i/q coordinate for a given angle using
39 * cordic algorithm. The coordinate consists of a real (i) and an
40 * imaginary (q) part. The real part is essentially the cosine of the
41 * angle and the imaginary part is the sine of the angle. The returned
42 * values are scaled by 2^16 for precision. The range for theta is
43 * for -180 degrees to +180 degrees. Passed values outside this range are
44 * converted before doing the actual calculation.
45 */
46struct cordic_iq cordic_calc_iq(s32 theta);
47
48#endif /* __CORDIC_H_ */