From 806d41b756fecc1b13584e2b806b76d8934b1679 Mon Sep 17 00:00:00 2001 From: Anssi Hannula Date: Wed, 19 Jul 2006 01:40:14 -0400 Subject: Input: move fixp-arith.h to drivers/input Move fixp-arith.h from drivers/usb/input to drivers/input, as the part of force feedback support that requires trigonometric functions is being moved there. Signed-off-by: Anssi Hannula Signed-off-by: Dmitry Torokhov --- drivers/input/fixp-arith.h | 87 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 drivers/input/fixp-arith.h (limited to 'drivers/input') diff --git a/drivers/input/fixp-arith.h b/drivers/input/fixp-arith.h new file mode 100644 index 000000000000..ed3d2da0c485 --- /dev/null +++ b/drivers/input/fixp-arith.h @@ -0,0 +1,87 @@ +#ifndef _FIXP_ARITH_H +#define _FIXP_ARITH_H + +/* + * Simplistic fixed-point arithmetics. + * Hmm, I'm probably duplicating some code :( + * + * Copyright (c) 2002 Johann Deneux + */ + +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Should you need to contact me, the author, you can do so by + * e-mail - mail your message to + */ + +#include + +/* The type representing fixed-point values */ +typedef s16 fixp_t; + +#define FRAC_N 8 +#define FRAC_MASK ((1< 123.0 */ +static inline fixp_t fixp_new(s16 a) +{ + return a< -1.0 + 0x8000 -> 1.0 + 0x0000 -> 0.0 +*/ +static inline fixp_t fixp_new16(s16 a) +{ + return ((s32)a)>>(16-FRAC_N); +} + +static inline fixp_t fixp_cos(unsigned int degrees) +{ + int quadrant = (degrees / 90) & 3; + unsigned int i = degrees % 90; + + if (quadrant == 1 || quadrant == 3) + i = 90 - i; + + i >>= 1; + + return (quadrant == 1 || quadrant == 2)? -cos_table[i] : cos_table[i]; +} + +static inline fixp_t fixp_sin(unsigned int degrees) +{ + return -fixp_cos(degrees + 90); +} + +static inline fixp_t fixp_mult(fixp_t a, fixp_t b) +{ + return ((s32)(a*b))>>FRAC_N; +} + +#endif -- cgit v1.2.3