| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * Copyright (c) 2015-2019, The Linux Foundation. All rights reserved. |
| */ |
| |
| #ifdef _FIXP_ARITH_H |
| #error "This implementation is meant to override fixp-arith.h, don't use both" |
| #endif |
| |
| #ifndef _FIXEDPOINT_H_ |
| #define _FIXEDPOINT_H_ |
| |
| #include <linux/types.h> |
| #include <linux/bits.h> |
| |
| /* |
| * Normally would typedef'ed, but checkpatch doesn't like typedef. |
| * Also should be normally typedef'ed to intmax_t but that doesn't seem to be |
| * available in the kernel |
| */ |
| #define fp_t size_t |
| |
| /* (Arbitrarily) make the first 25% of the bits to be the fractional bits */ |
| #define FP_FRACTIONAL_BITS ((sizeof(fp_t) * 8) / 4) |
| |
| #define FP(__i, __f_n, __f_d) \ |
| ((((fp_t)(__i)) << FP_FRACTIONAL_BITS) + \ |
| (((__f_n) << FP_FRACTIONAL_BITS) / (__f_d))) |
| |
| #define FP_INT(__i) FP(__i, 0, 1) |
| #define FP_ONE FP_INT(1) |
| #define FP_ZERO FP_INT(0) |
| |
| static inline size_t fp_frac_base(void) |
| { |
| return GENMASK(FP_FRACTIONAL_BITS - 1, 0); |
| } |
| |
| static inline size_t fp_frac(fp_t a) |
| { |
| return a & GENMASK(FP_FRACTIONAL_BITS - 1, 0); |
| } |
| |
| static inline size_t fp_int(fp_t a) |
| { |
| return a >> FP_FRACTIONAL_BITS; |
| } |
| |
| static inline size_t fp_round(fp_t a) |
| { |
| /* is the fractional part >= frac_max / 2? */ |
| bool round_up = fp_frac(a) >= fp_frac_base() / 2; |
| |
| return fp_int(a) + round_up; |
| } |
| |
| static inline fp_t fp_mult(fp_t a, fp_t b) |
| { |
| return (a * b) >> FP_FRACTIONAL_BITS; |
| } |
| |
| |
| static inline fp_t fp_div(fp_t a, fp_t b) |
| { |
| return (a << FP_FRACTIONAL_BITS) / b; |
| } |
| |
| #endif |