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 <linux/log2.h>
17
18 #include "type_support.h"
19 #include "math_support.h"
20 #include "sh_css_defs.h"
21 #include "ia_css_types.h"
22 #include "assert_support.h"
23 #include "ia_css_xnr3.host.h"
24
25 /* Maximum value for alpha on ISP interface */
26 #define XNR_MAX_ALPHA ((1 << (ISP_VEC_ELEMBITS - 1)) - 1)
27
28 /* Minimum value for sigma on host interface. Lower values translate to
29 * max_alpha.
30 */
31 #define XNR_MIN_SIGMA (IA_CSS_XNR3_SIGMA_SCALE / 100)
32
33 /*
34 * division look-up table
35 * Refers to XNR3.0.5
36 */
37 #define XNR3_LOOK_UP_TABLE_POINTS 16
38
39 static const s16 x[XNR3_LOOK_UP_TABLE_POINTS] = {
40 1024, 1164, 1320, 1492, 1680, 1884, 2108, 2352,
41 2616, 2900, 3208, 3540, 3896, 4276, 4684, 5120
42 };
43
44 static const s16 a[XNR3_LOOK_UP_TABLE_POINTS] = {
45 -7213, -5580, -4371, -3421, -2722, -2159, -6950, -5585,
46 -4529, -3697, -3010, -2485, -2070, -1727, -1428, 0
47 };
48
49 static const s16 b[XNR3_LOOK_UP_TABLE_POINTS] = {
50 4096, 3603, 3178, 2811, 2497, 2226, 1990, 1783,
51 1603, 1446, 1307, 1185, 1077, 981, 895, 819
52 };
53
54 static const s16 c[XNR3_LOOK_UP_TABLE_POINTS] = {
55 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
56 };
57
58 /*
59 * Default kernel parameters. In general, default is bypass mode or as close
60 * to the ineffective values as possible. Due to the chroma down+upsampling,
61 * perfect bypass mode is not possible for xnr3 filter itself. Instead, the
62 * 'blending' parameter is used to create a bypass.
63 */
64 const struct ia_css_xnr3_config default_xnr3_config = {
65 /* sigma */
66 { 0, 0, 0, 0, 0, 0 },
67 /* coring */
68 { 0, 0, 0, 0 },
69 /* blending */
70 { 0 }
71 };
72
73 /*
74 * Compute an alpha value for the ISP kernel from sigma value on the host
75 * parameter interface as: alpha_scale * 1/(sigma/sigma_scale)
76 */
77 static int32_t
compute_alpha(int sigma)78 compute_alpha(int sigma)
79 {
80 s32 alpha;
81 int offset = sigma / 2;
82
83 if (sigma < XNR_MIN_SIGMA) {
84 alpha = XNR_MAX_ALPHA;
85 } else {
86 alpha = ((IA_CSS_XNR3_SIGMA_SCALE * XNR_ALPHA_SCALE_FACTOR) + offset) / sigma;
87
88 if (alpha > XNR_MAX_ALPHA)
89 alpha = XNR_MAX_ALPHA;
90 }
91
92 return alpha;
93 }
94
95 /*
96 * Compute the scaled coring value for the ISP kernel from the value on the
97 * host parameter interface.
98 */
99 static int32_t
compute_coring(int coring)100 compute_coring(int coring)
101 {
102 s32 isp_coring;
103 s32 isp_scale = XNR_CORING_SCALE_FACTOR;
104 s32 host_scale = IA_CSS_XNR3_CORING_SCALE;
105 s32 offset = host_scale / 2; /* fixed-point 0.5 */
106
107 /* Convert from public host-side scale factor to isp-side scale
108 * factor. Clip to [0, isp_scale-1).
109 */
110 isp_coring = ((coring * isp_scale) + offset) / host_scale;
111 return clamp(isp_coring, 0, isp_scale - 1);
112 }
113
114 /*
115 * Compute the scaled blending strength for the ISP kernel from the value on
116 * the host parameter interface.
117 */
118 static int32_t
compute_blending(int strength)119 compute_blending(int strength)
120 {
121 s32 isp_strength;
122 s32 isp_scale = XNR_BLENDING_SCALE_FACTOR;
123 s32 host_scale = IA_CSS_XNR3_BLENDING_SCALE;
124 s32 offset = host_scale / 2; /* fixed-point 0.5 */
125
126 /* Convert from public host-side scale factor to isp-side scale
127 * factor. The blending factor is positive on the host side, but
128 * negative on the ISP side because +1.0 cannot be represented
129 * exactly as s0.11 fixed point, but -1.0 can.
130 */
131 isp_strength = -(((strength * isp_scale) + offset) / host_scale);
132 return MAX(MIN(isp_strength, 0), -isp_scale);
133 }
134
135 void
ia_css_xnr3_encode(struct sh_css_isp_xnr3_params * to,const struct ia_css_xnr3_config * from,unsigned int size)136 ia_css_xnr3_encode(
137 struct sh_css_isp_xnr3_params *to,
138 const struct ia_css_xnr3_config *from,
139 unsigned int size)
140 {
141 int kernel_size = XNR_FILTER_SIZE;
142 int adjust_factor = roundup_pow_of_two(kernel_size);
143 s32 max_diff = (1 << (ISP_VEC_ELEMBITS - 1)) - 1;
144 s32 min_diff = -(1 << (ISP_VEC_ELEMBITS - 1));
145
146 s32 alpha_y0 = compute_alpha(from->sigma.y0);
147 s32 alpha_y1 = compute_alpha(from->sigma.y1);
148 s32 alpha_u0 = compute_alpha(from->sigma.u0);
149 s32 alpha_u1 = compute_alpha(from->sigma.u1);
150 s32 alpha_v0 = compute_alpha(from->sigma.v0);
151 s32 alpha_v1 = compute_alpha(from->sigma.v1);
152 s32 alpha_ydiff = (alpha_y1 - alpha_y0) * adjust_factor / kernel_size;
153 s32 alpha_udiff = (alpha_u1 - alpha_u0) * adjust_factor / kernel_size;
154 s32 alpha_vdiff = (alpha_v1 - alpha_v0) * adjust_factor / kernel_size;
155
156 s32 coring_u0 = compute_coring(from->coring.u0);
157 s32 coring_u1 = compute_coring(from->coring.u1);
158 s32 coring_v0 = compute_coring(from->coring.v0);
159 s32 coring_v1 = compute_coring(from->coring.v1);
160 s32 coring_udiff = (coring_u1 - coring_u0) * adjust_factor / kernel_size;
161 s32 coring_vdiff = (coring_v1 - coring_v0) * adjust_factor / kernel_size;
162
163 s32 blending = compute_blending(from->blending.strength);
164
165 (void)size;
166
167 /* alpha's are represented in qN.5 format */
168 to->alpha.y0 = alpha_y0;
169 to->alpha.u0 = alpha_u0;
170 to->alpha.v0 = alpha_v0;
171 to->alpha.ydiff = clamp(alpha_ydiff, min_diff, max_diff);
172 to->alpha.udiff = clamp(alpha_udiff, min_diff, max_diff);
173 to->alpha.vdiff = clamp(alpha_vdiff, min_diff, max_diff);
174
175 /* coring parameters are expressed in q1.NN format */
176 to->coring.u0 = coring_u0;
177 to->coring.v0 = coring_v0;
178 to->coring.udiff = clamp(coring_udiff, min_diff, max_diff);
179 to->coring.vdiff = clamp(coring_vdiff, min_diff, max_diff);
180
181 /* blending strength is expressed in q1.NN format */
182 to->blending.strength = blending;
183 }
184
185 /* ISP2401 */
186 /* (void) = ia_css_xnr3_vmem_encode(*to, *from)
187 * -----------------------------------------------
188 * VMEM Encode Function to translate UV parameters from userspace into ISP space
189 */
190 void
ia_css_xnr3_vmem_encode(struct sh_css_isp_xnr3_vmem_params * to,const struct ia_css_xnr3_config * from,unsigned int size)191 ia_css_xnr3_vmem_encode(
192 struct sh_css_isp_xnr3_vmem_params *to,
193 const struct ia_css_xnr3_config *from,
194 unsigned int size)
195 {
196 unsigned int i, j, base;
197 const unsigned int total_blocks = 4;
198 const unsigned int shuffle_block = 16;
199
200 (void)from;
201 (void)size;
202
203 /* Init */
204 for (i = 0; i < ISP_VEC_NELEMS; i++) {
205 to->x[0][i] = 0;
206 to->a[0][i] = 0;
207 to->b[0][i] = 0;
208 to->c[0][i] = 0;
209 }
210
211 /* Constraints on "x":
212 * - values should be greater or equal to 0.
213 * - values should be ascending.
214 */
215 assert(x[0] >= 0);
216
217 for (j = 1; j < XNR3_LOOK_UP_TABLE_POINTS; j++) {
218 assert(x[j] >= 0);
219 assert(x[j] > x[j - 1]);
220 }
221
222 /* The implementation of the calulating 1/x is based on the availability
223 * of the OP_vec_shuffle16 operation.
224 * A 64 element vector is split up in 4 blocks of 16 element. Each array is copied to
225 * a vector 4 times, (starting at 0, 16, 32 and 48). All array elements are copied or
226 * initialised as described in the KFS. The remaining elements of a vector are set to 0.
227 */
228 /* TODO: guard this code with above assumptions */
229 for (i = 0; i < total_blocks; i++) {
230 base = shuffle_block * i;
231
232 for (j = 0; j < XNR3_LOOK_UP_TABLE_POINTS; j++) {
233 to->x[0][base + j] = x[j];
234 to->a[0][base + j] = a[j];
235 to->b[0][base + j] = b[j];
236 to->c[0][base + j] = c[j];
237 }
238 }
239 }
240
241 /* Dummy Function added as the tool expects it*/
242 void
ia_css_xnr3_debug_dtrace(const struct ia_css_xnr3_config * config,unsigned int level)243 ia_css_xnr3_debug_dtrace(
244 const struct ia_css_xnr3_config *config,
245 unsigned int level)
246 {
247 (void)config;
248 (void)level;
249 }
250