blob: 3d656f54d64f6247f47264544ea0826f5bfa1153 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
|
/*
* 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 <linux/types.h>
#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_ */
|
