1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Support for Intel Camera Imaging ISP subsystem.
4 * Copyright (c) 2015, Intel Corporation.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 #ifndef __SH_CSS_FRAC_H
17 #define __SH_CSS_FRAC_H
19 #include <math_support.h>
21 #define sISP_REG_BIT ISP_VEC_ELEMBITS
22 #define uISP_REG_BIT ((unsigned int)(sISP_REG_BIT - 1))
23 #define sSHIFT (16 - sISP_REG_BIT)
24 #define uSHIFT ((unsigned int)(16 - uISP_REG_BIT))
25 #define sFRACTION_BITS_FITTING(a) (a - sSHIFT)
26 #define uFRACTION_BITS_FITTING(a) ((unsigned int)(a - uSHIFT))
27 #define sISP_VAL_MIN (-(1 << uISP_REG_BIT))
28 #define sISP_VAL_MAX ((1 << uISP_REG_BIT) - 1)
29 #define uISP_VAL_MIN (0U)
30 #define uISP_VAL_MAX ((unsigned int)((1 << uISP_REG_BIT) - 1))
32 /* a:fraction bits for 16bit precision, b:fraction bits for ISP precision */
33 #define sDIGIT_FITTING(v, a, b) \
34 min_t(int, max_t(int, (((v) >> sSHIFT) >> max(sFRACTION_BITS_FITTING(a) - (b), 0)), \
35 sISP_VAL_MIN), sISP_VAL_MAX)
36 #define uDIGIT_FITTING(v, a, b) \
37 min((unsigned int)max((unsigned)(((v) >> uSHIFT) \
38 >> max((int)(uFRACTION_BITS_FITTING(a) - (b)), 0)), \
39 uISP_VAL_MIN), uISP_VAL_MAX)
41 #endif /* __SH_CSS_FRAC_H */