xref: /linux/drivers/gpu/drm/amd/display/dc/basics/conversion.c (revision 570f7e331f5febb30f1384817463c7e42b65ca7d)
1 /*
2  * Copyright 2012-15 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: AMD
23  *
24  */
25 
26 #include "dm_services.h"
27 #include "basics/conversion.h"
28 
29 
30 
31 uint16_t fixed_point_to_int_frac(
32 	struct fixed31_32 arg,
33 	uint8_t integer_bits,
34 	uint8_t fractional_bits)
35 {
36 	int32_t numerator;
37 	int32_t divisor = 1 << fractional_bits;
38 
39 	uint16_t result;
40 
41 	uint16_t d = (uint16_t)dc_fixpt_floor(
42 		dc_fixpt_abs(
43 			arg));
44 
45 	if (d <= (uint16_t)(1 << integer_bits) - (1 / (uint16_t)divisor))
46 		numerator = (uint16_t)dc_fixpt_round(
47 			dc_fixpt_mul_int(
48 				arg,
49 				divisor));
50 	else {
51 		numerator = dc_fixpt_floor(
52 			dc_fixpt_sub(
53 				dc_fixpt_from_int(
54 					1LL << integer_bits),
55 				dc_fixpt_recip(
56 					dc_fixpt_from_int(
57 						divisor))));
58 	}
59 
60 	if (numerator >= 0)
61 		result = (uint16_t)numerator;
62 	else
63 		result = (uint16_t)(
64 		(1 << (integer_bits + fractional_bits + 1)) + numerator);
65 
66 	if ((result != 0) && dc_fixpt_lt(
67 		arg, dc_fixpt_zero))
68 		result |= 1 << (integer_bits + fractional_bits);
69 
70 	return result;
71 }
72 /*
73  * convert_float_matrix - This converts a double into HW register spec defined format S2D13 / S3D12.
74  */
75 void convert_float_matrix(
76 	uint16_t *matrix,
77 	const struct fixed31_32 *flt,
78 	enum cm_gamut_coef_format format,
79 	uint32_t buffer_size)
80 {
81 	struct fixed31_32 min;
82 	struct fixed31_32 max;
83 	uint8_t num_int_bits;
84 	uint8_t num_dec_bits;
85 	uint32_t i;
86 
87 	if (format == CM_GAMUT_REMAP_COEF_FORMAT_S2_13) {
88 		min = dc_fixpt_from_fraction(S2D13_MIN, DIVIDER);
89 		max = dc_fixpt_from_fraction(S2D13_MAX, DIVIDER);
90 		num_int_bits = 2;
91 		num_dec_bits = 13;
92 	} else if (format == CM_GAMUT_REMAP_COEF_FORMAT_S3_12) {
93 		min = dc_fixpt_from_fraction(S3D12_MIN, DIVIDER);
94 		max = dc_fixpt_from_fraction(S3D12_MAX, DIVIDER);
95 		num_int_bits = 3;
96 		num_dec_bits = 12;
97 	} else {
98 		ASSERT(false);
99 		return;
100 	}
101 
102 	for (i = 0; i < buffer_size; ++i) {
103 		uint32_t reg_value =
104 				fixed_point_to_int_frac(
105 					dc_fixpt_clamp(
106 						flt[i],
107 						min,
108 						max),
109 						num_int_bits,
110 						num_dec_bits);
111 
112 		matrix[i] = (uint16_t)reg_value;
113 	}
114 }
115 
116 static struct fixed31_32 int_frac_to_fixed_point(uint16_t arg,
117 						 uint8_t integer_bits,
118 						 uint8_t fractional_bits)
119 {
120 	struct fixed31_32 result;
121 	uint16_t sign_mask = 1 << (fractional_bits + integer_bits);
122 	uint16_t value_mask = sign_mask - 1;
123 
124 	result.value = (long long)(arg & value_mask) <<
125 		       (FIXED31_32_BITS_PER_FRACTIONAL_PART - fractional_bits);
126 
127 	if (arg & sign_mask)
128 		result = dc_fixpt_neg(result);
129 
130 	return result;
131 }
132 
133 /**
134  * convert_hw_matrix - converts HW values into fixed31_32 matrix.
135  * @matrix: fixed point 31.32 matrix
136  * @reg: array of register values
137  * @buffer_size: size of the array of register values
138  *
139  * Converts HW register spec defined format S2D13 into a fixed-point 31.32
140  * matrix.
141  */
142 void convert_hw_matrix(struct fixed31_32 *matrix,
143 		       uint16_t *reg,
144 			   enum cm_gamut_coef_format format,
145 		       uint32_t buffer_size)
146 {
147 	uint8_t num_int_bits;
148 	uint8_t num_dec_bits;
149 	uint32_t i;
150 
151 	if (format == CM_GAMUT_REMAP_COEF_FORMAT_S2_13) {
152 		num_int_bits = 2;
153 		num_dec_bits = 13;
154 	} else if (format == CM_GAMUT_REMAP_COEF_FORMAT_S3_12) {
155 		num_int_bits = 3;
156 		num_dec_bits = 12;
157 	} else {
158 		ASSERT(false);
159 		return;
160 	}
161 
162 	for (i = 0; i < buffer_size; ++i)
163 		matrix[i] = int_frac_to_fixed_point(reg[i],
164 							num_int_bits, num_dec_bits);
165 }
166 
167 static uint32_t find_gcd(uint32_t a, uint32_t b)
168 {
169 	uint32_t remainder;
170 
171 	while (b != 0) {
172 		remainder = a % b;
173 		a = b;
174 		b = remainder;
175 	}
176 	return a;
177 }
178 
179 void reduce_fraction(uint32_t num, uint32_t den,
180 		uint32_t *out_num, uint32_t *out_den)
181 {
182 	uint32_t gcd = 0;
183 
184 	gcd = find_gcd(num, den);
185 	*out_num = num / gcd;
186 	*out_den = den / gcd;
187 }
188