1/*
2 * Copyright 2009 Red Hat Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: Dave Airlie
23 */
24
25#include <sys/cdefs.h>
26#ifndef DRM_FIXED_H
27#define DRM_FIXED_H
28
29typedef union dfixed {
30	u32 full;
31} fixed20_12;
32
33
34#define dfixed_const(A) (u32)(((A) << 12))/*  + ((B + 0.000122)*4096)) */
35#define dfixed_const_half(A) (u32)(((A) << 12) + 2048)
36#define dfixed_const_666(A) (u32)(((A) << 12) + 2731)
37#define dfixed_const_8(A) (u32)(((A) << 12) + 3277)
38#define dfixed_mul(A, B) ((u64)((u64)(A).full * (B).full + 2048) >> 12)
39#define dfixed_init(A) { .full = dfixed_const((A)) }
40#define dfixed_init_half(A) { .full = dfixed_const_half((A)) }
41#define dfixed_trunc(A) ((A).full >> 12)
42#define dfixed_frac(A) ((A).full & ((1 << 12) - 1))
43
44static inline u32 dfixed_floor(fixed20_12 A)
45{
46	u32 non_frac = dfixed_trunc(A);
47
48	return dfixed_const(non_frac);
49}
50
51static inline u32 dfixed_ceil(fixed20_12 A)
52{
53	u32 non_frac = dfixed_trunc(A);
54
55	if (A.full > dfixed_const(non_frac))
56		return dfixed_const(non_frac + 1);
57	else
58		return dfixed_const(non_frac);
59}
60
61static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B)
62{
63	u64 tmp = ((u64)A.full << 13);
64
65	do_div(tmp, B.full);
66	tmp += 1;
67	tmp /= 2;
68	return lower_32_bits(tmp);
69}
70#endif
71