linux/include/drm/drm_fixed.h

69 lines
2.2 KiB
C

/*
* Copyright 2009 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: Dave Airlie
*/
#ifndef DRM_FIXED_H
#define DRM_FIXED_H
typedef union dfixed {
u32 full;
} fixed20_12;
#define dfixed_const(A) (u32)(((A) << 12))/* + ((B + 0.000122)*4096)) */
#define dfixed_const_half(A) (u32)(((A) << 12) + 2048)
#define dfixed_const_666(A) (u32)(((A) << 12) + 2731)
#define dfixed_const_8(A) (u32)(((A) << 12) + 3277)
#define dfixed_mul(A, B) ((u64)((u64)(A).full * (B).full + 2048) >> 12)
#define dfixed_init(A) { .full = dfixed_const((A)) }
#define dfixed_init_half(A) { .full = dfixed_const_half((A)) }
#define dfixed_trunc(A) ((A).full >> 12)
#define dfixed_frac(A) ((A).full & ((1 << 12) - 1))
static inline u32 dfixed_floor(fixed20_12 A)
{
u32 non_frac = dfixed_trunc(A);
return dfixed_const(non_frac);
}
static inline u32 dfixed_ceil(fixed20_12 A)
{
u32 non_frac = dfixed_trunc(A);
if (A.full > dfixed_const(non_frac))
return dfixed_const(non_frac + 1);
else
return dfixed_const(non_frac);
}
static inline u32 dfixed_div(fixed20_12 A, fixed20_12 B)
{
u64 tmp = ((u64)A.full << 13);
do_div(tmp, B.full);
tmp += 1;
tmp /= 2;
return lower_32_bits(tmp);
}
#endif