LXR linux/drivers/staging/media/atomisp/pci/isp/kernels/ctc/ctc1_5/ia_css_ctc1

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Support for Intel Camera Imaging ISP subsystem.
   4 * Copyright (c) 2015, Intel Corporation.
   5 *
   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.
   9 *
  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
  13 * more details.
  14 */
  15
  16#include "ia_css_types.h"
  17#include "sh_css_defs.h"
  18#include "ia_css_debug.h"
  19#include "assert_support.h"
  20
  21#include "ctc/ctc_1.0/ia_css_ctc.host.h"
  22#include "ia_css_ctc1_5.host.h"
  23
  24static void ctc_gradient(
  25    int *dydx, int *shift,
  26    int y1, int y0, int x1, int x0)
  27{
  28        int frc_bits = max(IA_CSS_CTC_COEF_SHIFT, 16);
  29        int dy = y1 - y0;
  30        int dx = x1 - x0;
  31        int dydx_int;
  32        int dydx_frc;
  33        int sft;
  34        /* max_dydx = the maxinum gradient = the maximum y (gain) */
  35        int max_dydx = (1 << IA_CSS_CTC_COEF_SHIFT) - 1;
  36
  37        if (dx == 0) {
  38                ia_css_debug_dtrace(IA_CSS_DEBUG_TRACE_PRIVATE,
  39                                    "ctc_gradient() error, illegal division operation\n");
  40                return;
  41        } else {
  42                dydx_int = dy / dx;
  43                dydx_frc = ((dy - dydx_int * dx) << frc_bits) / dx;
  44        }
  45
  46        assert(y0 >= 0 && y0 <= max_dydx);
  47        assert(y1 >= 0 && y1 <= max_dydx);
  48        assert(x0 < x1);
  49        assert(dydx);
  50        assert(shift);
  51
  52        ia_css_debug_dtrace(IA_CSS_DEBUG_TRACE_PRIVATE, "ctc_gradient() enter:\n");
  53
  54        /* search "sft" which meets this condition:
  55                   (1 << (IA_CSS_CTC_COEF_SHIFT - 1))
  56                <= (((float)dy / (float)dx) * (1 << sft))
  57                <= ((1 << IA_CSS_CTC_COEF_SHIFT) - 1) */
  58        for (sft = 0; sft <= IA_CSS_CTC_COEF_SHIFT; sft++) {
  59                int tmp_dydx = (dydx_int << sft)
  60                               + (dydx_frc >> (frc_bits - sft));
  61                if (tmp_dydx <= max_dydx) {
  62                        *dydx = tmp_dydx;
  63                        *shift = sft;
  64                }
  65                if (tmp_dydx >= max_dydx)
  66                        break;
  67        }
  68
  69        ia_css_debug_dtrace(IA_CSS_DEBUG_TRACE_PRIVATE, "ctc_gradient() leave:\n");
  70}
  71
  72void
  73ia_css_ctc_encode(
  74    struct sh_css_isp_ctc_params *to,
  75    const struct ia_css_ctc_config *from,
  76    unsigned int size)
  77{
  78        (void)size;
  79        to->y0 = from->y0;
  80        to->y1 = from->y1;
  81        to->y2 = from->y2;
  82        to->y3 = from->y3;
  83        to->y4 = from->y4;
  84        to->y5 = from->y5;
  85
  86        to->ce_gain_exp = from->ce_gain_exp;
  87
  88        to->x1 = from->x1;
  89        to->x2 = from->x2;
  90        to->x3 = from->x3;
  91        to->x4 = from->x4;
  92
  93        ctc_gradient(&to->dydx0,
  94                     &to->dydx0_shift,
  95                     from->y1, from->y0,
  96                     from->x1, 0);
  97
  98        ctc_gradient(&to->dydx1,
  99                     &to->dydx1_shift,
 100                     from->y2, from->y1,
 101                     from->x2, from->x1);
 102
 103        ctc_gradient(&to->dydx2,
 104                     &to->dydx2_shift,
 105                     from->y3, from->y2,
 106                     from->x3, from->x2);
 107
 108        ctc_gradient(&to->dydx3,
 109                     &to->dydx3_shift,
 110                     from->y4, from->y3,
 111                     from->x4, from->x3);
 112
 113        ctc_gradient(&to->dydx4,
 114                     &to->dydx4_shift,
 115                     from->y5, from->y4,
 116                     SH_CSS_BAYER_MAXVAL, from->x4);
 117}
 118
 119void
 120ia_css_ctc_dump(
 121    const struct sh_css_isp_ctc_params *ctc,
 122    unsigned int level);
 123