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 "assert_support.h"
19 
20 #include "ia_css_ctc2.host.h"
21 
22 #define INEFFECTIVE_VAL 4096
23 #define BASIC_VAL 819
24 
25 /*Default configuration of parameters for Ctc2*/
26 const struct ia_css_ctc2_config default_ctc2_config = {
27 	INEFFECTIVE_VAL, INEFFECTIVE_VAL, INEFFECTIVE_VAL,
28 	INEFFECTIVE_VAL, INEFFECTIVE_VAL, INEFFECTIVE_VAL,
29 	BASIC_VAL * 2, BASIC_VAL * 4, BASIC_VAL * 6,
30 	BASIC_VAL * 8, INEFFECTIVE_VAL, INEFFECTIVE_VAL,
31 	BASIC_VAL >> 1, BASIC_VAL
32 };
33 
34 /* (dydx) = ctc2_slope(y1, y0, x1, x0)
35  * -----------------------------------------------
36  * Calculation of the Slope of a Line = ((y1 - y0) >> 8)/(x1 - x0)
37  *
38  * Note: y1, y0 , x1 & x0 must lie within the range 0 <-> 8191
39  */
ctc2_slope(int y1,int y0,int x1,int x0)40 static int ctc2_slope(int y1, int y0, int x1, int x0)
41 {
42 	const int shift_val = 8;
43 	const int max_slope = (1 << IA_CSS_CTC_COEF_SHIFT) - 1;
44 	int dy = y1 - y0;
45 	int dx = x1 - x0;
46 	int rounding = (dx + 1) >> 1;
47 	int dy_shift = dy << shift_val;
48 	int slope, dydx;
49 
50 	/*Protection for parameter values, & avoiding zero divisions*/
51 	assert(y0 >= 0 && y0 <= max_slope);
52 	assert(y1 >= 0 && y1 <= max_slope);
53 	assert(x0 >= 0 && x0 <= max_slope);
54 	assert(x1 > 0 && x1 <= max_slope);
55 	assert(dx > 0);
56 
57 	if (dy < 0)
58 		rounding = -rounding;
59 	slope = (int)(dy_shift + rounding) / dx;
60 
61 	/*the slope must lie within the range
62 	  (-max_slope-1) >= (dydx) >= (max_slope)
63 	*/
64 	if (slope <= -max_slope - 1) {
65 		dydx = -max_slope - 1;
66 	} else if (slope >= max_slope) {
67 		dydx = max_slope;
68 	} else {
69 		dydx = slope;
70 	}
71 
72 	return dydx;
73 }
74 
75 /* (void) = ia_css_ctc2_vmem_encode(*to, *from)
76  * -----------------------------------------------
77  * VMEM Encode Function to translate Y parameters from userspace into ISP space
78  */
ia_css_ctc2_vmem_encode(struct ia_css_isp_ctc2_vmem_params * to,const struct ia_css_ctc2_config * from,size_t size)79 void ia_css_ctc2_vmem_encode(struct ia_css_isp_ctc2_vmem_params *to,
80 			     const struct ia_css_ctc2_config *from,
81 			     size_t size)
82 {
83 	unsigned int i, j;
84 	const unsigned int shffl_blck = 4;
85 	const unsigned int length_zeros = 11;
86 	short dydx0, dydx1, dydx2, dydx3, dydx4;
87 
88 	(void)size;
89 	/*
90 	*  Calculation of slopes of lines interconnecting
91 	*  0.0 -> y_x1 -> y_x2 -> y _x3 -> y_x4 -> 1.0
92 	*/
93 	dydx0 = ctc2_slope(from->y_y1, from->y_y0,
94 			   from->y_x1, 0);
95 	dydx1 = ctc2_slope(from->y_y2, from->y_y1,
96 			   from->y_x2, from->y_x1);
97 	dydx2 = ctc2_slope(from->y_y3, from->y_y2,
98 			   from->y_x3, from->y_x2);
99 	dydx3 = ctc2_slope(from->y_y4, from->y_y3,
100 			   from->y_x4, from->y_x3);
101 	dydx4 = ctc2_slope(from->y_y5, from->y_y4,
102 			   SH_CSS_BAYER_MAXVAL, from->y_x4);
103 
104 	/*Fill 3 arrays with:
105 	 * - Luma input gain values y_y0, y_y1, y_y2, y_3, y_y4
106 	 * - Luma kneepoints 0, y_x1, y_x2, y_x3, y_x4
107 	 * - Calculated slopes dydx0, dyxd1, dydx2, dydx3, dydx4
108 	 *
109 	 * - Each 64-element array is divided in blocks of 16 elements:
110 	 *   the 5 parameters + zeros in the remaining 11 positions
111 	 * - All blocks of the same array will contain the same data
112 	 */
113 	for (i = 0; i < shffl_blck; i++) {
114 		to->y_x[0][(i << shffl_blck)]     = 0;
115 		to->y_x[0][(i << shffl_blck) + 1] = from->y_x1;
116 		to->y_x[0][(i << shffl_blck) + 2] = from->y_x2;
117 		to->y_x[0][(i << shffl_blck) + 3] = from->y_x3;
118 		to->y_x[0][(i << shffl_blck) + 4] = from->y_x4;
119 
120 		to->y_y[0][(i << shffl_blck)]     = from->y_y0;
121 		to->y_y[0][(i << shffl_blck) + 1] = from->y_y1;
122 		to->y_y[0][(i << shffl_blck) + 2] = from->y_y2;
123 		to->y_y[0][(i << shffl_blck) + 3] = from->y_y3;
124 		to->y_y[0][(i << shffl_blck) + 4] = from->y_y4;
125 
126 		to->e_y_slope[0][(i << shffl_blck)]    = dydx0;
127 		to->e_y_slope[0][(i << shffl_blck) + 1] = dydx1;
128 		to->e_y_slope[0][(i << shffl_blck) + 2] = dydx2;
129 		to->e_y_slope[0][(i << shffl_blck) + 3] = dydx3;
130 		to->e_y_slope[0][(i << shffl_blck) + 4] = dydx4;
131 
132 		for (j = 0; j < length_zeros; j++) {
133 			to->y_x[0][(i << shffl_blck) + 5 + j] = 0;
134 			to->y_y[0][(i << shffl_blck) + 5 + j] = 0;
135 			to->e_y_slope[0][(i << shffl_blck) + 5 + j] = 0;
136 		}
137 	}
138 }
139 
140 /* (void) = ia_css_ctc2_encode(*to, *from)
141  * -----------------------------------------------
142  * DMEM Encode Function to translate UV parameters from userspace into ISP space
143  */
ia_css_ctc2_encode(struct ia_css_isp_ctc2_dmem_params * to,struct ia_css_ctc2_config * from,size_t size)144 void ia_css_ctc2_encode(struct ia_css_isp_ctc2_dmem_params *to,
145 			struct ia_css_ctc2_config *from,
146 			size_t size)
147 {
148 	(void)size;
149 
150 	to->uv_y0 = from->uv_y0;
151 	to->uv_y1 = from->uv_y1;
152 	to->uv_x0 = from->uv_x0;
153 	to->uv_x1 = from->uv_x1;
154 
155 	/*Slope Calculation*/
156 	to->uv_dydx = ctc2_slope(from->uv_y1, from->uv_y0,
157 				 from->uv_x1, from->uv_x0);
158 }
159