1 /* 2 * v4l2-dv-timings - dv-timings helper functions 3 * 4 * Copyright 2013 Cisco Systems, Inc. and/or its affiliates. All rights reserved. 5 * 6 * This program is free software; you may redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; version 2 of the License. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 17 * SOFTWARE. 18 * 19 */ 20 21 #include <linux/module.h> 22 #include <linux/types.h> 23 #include <linux/kernel.h> 24 #include <linux/errno.h> 25 #include <linux/videodev2.h> 26 #include <linux/v4l2-dv-timings.h> 27 #include <media/v4l2-dv-timings.h> 28 #include <linux/math64.h> 29 30 MODULE_AUTHOR("Hans Verkuil"); 31 MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions"); 32 MODULE_LICENSE("GPL"); 33 34 const struct v4l2_dv_timings v4l2_dv_timings_presets[] = { 35 V4L2_DV_BT_CEA_640X480P59_94, 36 V4L2_DV_BT_CEA_720X480I59_94, 37 V4L2_DV_BT_CEA_720X480P59_94, 38 V4L2_DV_BT_CEA_720X576I50, 39 V4L2_DV_BT_CEA_720X576P50, 40 V4L2_DV_BT_CEA_1280X720P24, 41 V4L2_DV_BT_CEA_1280X720P25, 42 V4L2_DV_BT_CEA_1280X720P30, 43 V4L2_DV_BT_CEA_1280X720P50, 44 V4L2_DV_BT_CEA_1280X720P60, 45 V4L2_DV_BT_CEA_1920X1080P24, 46 V4L2_DV_BT_CEA_1920X1080P25, 47 V4L2_DV_BT_CEA_1920X1080P30, 48 V4L2_DV_BT_CEA_1920X1080I50, 49 V4L2_DV_BT_CEA_1920X1080P50, 50 V4L2_DV_BT_CEA_1920X1080I60, 51 V4L2_DV_BT_CEA_1920X1080P60, 52 V4L2_DV_BT_DMT_640X350P85, 53 V4L2_DV_BT_DMT_640X400P85, 54 V4L2_DV_BT_DMT_720X400P85, 55 V4L2_DV_BT_DMT_640X480P72, 56 V4L2_DV_BT_DMT_640X480P75, 57 V4L2_DV_BT_DMT_640X480P85, 58 V4L2_DV_BT_DMT_800X600P56, 59 V4L2_DV_BT_DMT_800X600P60, 60 V4L2_DV_BT_DMT_800X600P72, 61 V4L2_DV_BT_DMT_800X600P75, 62 V4L2_DV_BT_DMT_800X600P85, 63 V4L2_DV_BT_DMT_800X600P120_RB, 64 V4L2_DV_BT_DMT_848X480P60, 65 V4L2_DV_BT_DMT_1024X768I43, 66 V4L2_DV_BT_DMT_1024X768P60, 67 V4L2_DV_BT_DMT_1024X768P70, 68 V4L2_DV_BT_DMT_1024X768P75, 69 V4L2_DV_BT_DMT_1024X768P85, 70 V4L2_DV_BT_DMT_1024X768P120_RB, 71 V4L2_DV_BT_DMT_1152X864P75, 72 V4L2_DV_BT_DMT_1280X768P60_RB, 73 V4L2_DV_BT_DMT_1280X768P60, 74 V4L2_DV_BT_DMT_1280X768P75, 75 V4L2_DV_BT_DMT_1280X768P85, 76 V4L2_DV_BT_DMT_1280X768P120_RB, 77 V4L2_DV_BT_DMT_1280X800P60_RB, 78 V4L2_DV_BT_DMT_1280X800P60, 79 V4L2_DV_BT_DMT_1280X800P75, 80 V4L2_DV_BT_DMT_1280X800P85, 81 V4L2_DV_BT_DMT_1280X800P120_RB, 82 V4L2_DV_BT_DMT_1280X960P60, 83 V4L2_DV_BT_DMT_1280X960P85, 84 V4L2_DV_BT_DMT_1280X960P120_RB, 85 V4L2_DV_BT_DMT_1280X1024P60, 86 V4L2_DV_BT_DMT_1280X1024P75, 87 V4L2_DV_BT_DMT_1280X1024P85, 88 V4L2_DV_BT_DMT_1280X1024P120_RB, 89 V4L2_DV_BT_DMT_1360X768P60, 90 V4L2_DV_BT_DMT_1360X768P120_RB, 91 V4L2_DV_BT_DMT_1366X768P60, 92 V4L2_DV_BT_DMT_1366X768P60_RB, 93 V4L2_DV_BT_DMT_1400X1050P60_RB, 94 V4L2_DV_BT_DMT_1400X1050P60, 95 V4L2_DV_BT_DMT_1400X1050P75, 96 V4L2_DV_BT_DMT_1400X1050P85, 97 V4L2_DV_BT_DMT_1400X1050P120_RB, 98 V4L2_DV_BT_DMT_1440X900P60_RB, 99 V4L2_DV_BT_DMT_1440X900P60, 100 V4L2_DV_BT_DMT_1440X900P75, 101 V4L2_DV_BT_DMT_1440X900P85, 102 V4L2_DV_BT_DMT_1440X900P120_RB, 103 V4L2_DV_BT_DMT_1600X900P60_RB, 104 V4L2_DV_BT_DMT_1600X1200P60, 105 V4L2_DV_BT_DMT_1600X1200P65, 106 V4L2_DV_BT_DMT_1600X1200P70, 107 V4L2_DV_BT_DMT_1600X1200P75, 108 V4L2_DV_BT_DMT_1600X1200P85, 109 V4L2_DV_BT_DMT_1600X1200P120_RB, 110 V4L2_DV_BT_DMT_1680X1050P60_RB, 111 V4L2_DV_BT_DMT_1680X1050P60, 112 V4L2_DV_BT_DMT_1680X1050P75, 113 V4L2_DV_BT_DMT_1680X1050P85, 114 V4L2_DV_BT_DMT_1680X1050P120_RB, 115 V4L2_DV_BT_DMT_1792X1344P60, 116 V4L2_DV_BT_DMT_1792X1344P75, 117 V4L2_DV_BT_DMT_1792X1344P120_RB, 118 V4L2_DV_BT_DMT_1856X1392P60, 119 V4L2_DV_BT_DMT_1856X1392P75, 120 V4L2_DV_BT_DMT_1856X1392P120_RB, 121 V4L2_DV_BT_DMT_1920X1200P60_RB, 122 V4L2_DV_BT_DMT_1920X1200P60, 123 V4L2_DV_BT_DMT_1920X1200P75, 124 V4L2_DV_BT_DMT_1920X1200P85, 125 V4L2_DV_BT_DMT_1920X1200P120_RB, 126 V4L2_DV_BT_DMT_1920X1440P60, 127 V4L2_DV_BT_DMT_1920X1440P75, 128 V4L2_DV_BT_DMT_1920X1440P120_RB, 129 V4L2_DV_BT_DMT_2048X1152P60_RB, 130 V4L2_DV_BT_DMT_2560X1600P60_RB, 131 V4L2_DV_BT_DMT_2560X1600P60, 132 V4L2_DV_BT_DMT_2560X1600P75, 133 V4L2_DV_BT_DMT_2560X1600P85, 134 V4L2_DV_BT_DMT_2560X1600P120_RB, 135 V4L2_DV_BT_CEA_3840X2160P24, 136 V4L2_DV_BT_CEA_3840X2160P25, 137 V4L2_DV_BT_CEA_3840X2160P30, 138 V4L2_DV_BT_CEA_3840X2160P50, 139 V4L2_DV_BT_CEA_3840X2160P60, 140 V4L2_DV_BT_CEA_4096X2160P24, 141 V4L2_DV_BT_CEA_4096X2160P25, 142 V4L2_DV_BT_CEA_4096X2160P30, 143 V4L2_DV_BT_CEA_4096X2160P50, 144 V4L2_DV_BT_DMT_4096X2160P59_94_RB, 145 V4L2_DV_BT_CEA_4096X2160P60, 146 { } 147 }; 148 EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets); 149 150 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t, 151 const struct v4l2_dv_timings_cap *dvcap, 152 v4l2_check_dv_timings_fnc fnc, 153 void *fnc_handle) 154 { 155 const struct v4l2_bt_timings *bt = &t->bt; 156 const struct v4l2_bt_timings_cap *cap = &dvcap->bt; 157 u32 caps = cap->capabilities; 158 159 if (t->type != V4L2_DV_BT_656_1120) 160 return false; 161 if (t->type != dvcap->type || 162 bt->height < cap->min_height || 163 bt->height > cap->max_height || 164 bt->width < cap->min_width || 165 bt->width > cap->max_width || 166 bt->pixelclock < cap->min_pixelclock || 167 bt->pixelclock > cap->max_pixelclock || 168 (!(caps & V4L2_DV_BT_CAP_CUSTOM) && 169 cap->standards && bt->standards && 170 !(bt->standards & cap->standards)) || 171 (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) || 172 (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE))) 173 return false; 174 return fnc == NULL || fnc(t, fnc_handle); 175 } 176 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings); 177 178 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t, 179 const struct v4l2_dv_timings_cap *cap, 180 v4l2_check_dv_timings_fnc fnc, 181 void *fnc_handle) 182 { 183 u32 i, idx; 184 185 memset(t->reserved, 0, sizeof(t->reserved)); 186 for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) { 187 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap, 188 fnc, fnc_handle) && 189 idx++ == t->index) { 190 t->timings = v4l2_dv_timings_presets[i]; 191 return 0; 192 } 193 } 194 return -EINVAL; 195 } 196 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap); 197 198 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t, 199 const struct v4l2_dv_timings_cap *cap, 200 unsigned pclock_delta, 201 v4l2_check_dv_timings_fnc fnc, 202 void *fnc_handle) 203 { 204 int i; 205 206 if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle)) 207 return false; 208 209 for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) { 210 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap, 211 fnc, fnc_handle) && 212 v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i, 213 pclock_delta, false)) { 214 u32 flags = t->bt.flags & V4L2_DV_FL_REDUCED_FPS; 215 216 *t = v4l2_dv_timings_presets[i]; 217 if (can_reduce_fps(&t->bt)) 218 t->bt.flags |= flags; 219 220 return true; 221 } 222 } 223 return false; 224 } 225 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap); 226 227 /** 228 * v4l2_match_dv_timings - check if two timings match 229 * @t1 - compare this v4l2_dv_timings struct... 230 * @t2 - with this struct. 231 * @pclock_delta - the allowed pixelclock deviation. 232 * @match_reduced_fps - if true, then fail if V4L2_DV_FL_REDUCED_FPS does not 233 * match. 234 * 235 * Compare t1 with t2 with a given margin of error for the pixelclock. 236 */ 237 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1, 238 const struct v4l2_dv_timings *t2, 239 unsigned pclock_delta, bool match_reduced_fps) 240 { 241 if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120) 242 return false; 243 if (t1->bt.width == t2->bt.width && 244 t1->bt.height == t2->bt.height && 245 t1->bt.interlaced == t2->bt.interlaced && 246 t1->bt.polarities == t2->bt.polarities && 247 t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta && 248 t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta && 249 t1->bt.hfrontporch == t2->bt.hfrontporch && 250 t1->bt.hsync == t2->bt.hsync && 251 t1->bt.hbackporch == t2->bt.hbackporch && 252 t1->bt.vfrontporch == t2->bt.vfrontporch && 253 t1->bt.vsync == t2->bt.vsync && 254 t1->bt.vbackporch == t2->bt.vbackporch && 255 (!match_reduced_fps || 256 (t1->bt.flags & V4L2_DV_FL_REDUCED_FPS) == 257 (t2->bt.flags & V4L2_DV_FL_REDUCED_FPS)) && 258 (!t1->bt.interlaced || 259 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch && 260 t1->bt.il_vsync == t2->bt.il_vsync && 261 t1->bt.il_vbackporch == t2->bt.il_vbackporch))) 262 return true; 263 return false; 264 } 265 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings); 266 267 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix, 268 const struct v4l2_dv_timings *t, bool detailed) 269 { 270 const struct v4l2_bt_timings *bt = &t->bt; 271 u32 htot, vtot; 272 u32 fps; 273 274 if (t->type != V4L2_DV_BT_656_1120) 275 return; 276 277 htot = V4L2_DV_BT_FRAME_WIDTH(bt); 278 vtot = V4L2_DV_BT_FRAME_HEIGHT(bt); 279 if (bt->interlaced) 280 vtot /= 2; 281 282 fps = (htot * vtot) > 0 ? div_u64((100 * (u64)bt->pixelclock), 283 (htot * vtot)) : 0; 284 285 if (prefix == NULL) 286 prefix = ""; 287 288 pr_info("%s: %s%ux%u%s%u.%u (%ux%u)\n", dev_prefix, prefix, 289 bt->width, bt->height, bt->interlaced ? "i" : "p", 290 fps / 100, fps % 100, htot, vtot); 291 292 if (!detailed) 293 return; 294 295 pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n", 296 dev_prefix, bt->hfrontporch, 297 (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-", 298 bt->hsync, bt->hbackporch); 299 pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n", 300 dev_prefix, bt->vfrontporch, 301 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-", 302 bt->vsync, bt->vbackporch); 303 if (bt->interlaced) 304 pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n", 305 dev_prefix, bt->il_vfrontporch, 306 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-", 307 bt->il_vsync, bt->il_vbackporch); 308 pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock); 309 pr_info("%s: flags (0x%x):%s%s%s%s%s%s\n", dev_prefix, bt->flags, 310 (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ? 311 " REDUCED_BLANKING" : "", 312 ((bt->flags & V4L2_DV_FL_REDUCED_BLANKING) && 313 bt->vsync == 8) ? " (V2)" : "", 314 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ? 315 " CAN_REDUCE_FPS" : "", 316 (bt->flags & V4L2_DV_FL_REDUCED_FPS) ? 317 " REDUCED_FPS" : "", 318 (bt->flags & V4L2_DV_FL_HALF_LINE) ? 319 " HALF_LINE" : "", 320 (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ? 321 " CE_VIDEO" : ""); 322 pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards, 323 (bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "", 324 (bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "", 325 (bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "", 326 (bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : ""); 327 } 328 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings); 329 330 /* 331 * CVT defines 332 * Based on Coordinated Video Timings Standard 333 * version 1.1 September 10, 2003 334 */ 335 336 #define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 337 #define CVT_PXL_CLK_GRAN_RB_V2 1000 /* granularity for reduced blanking v2*/ 338 339 /* Normal blanking */ 340 #define CVT_MIN_V_BPORCH 7 /* lines */ 341 #define CVT_MIN_V_PORCH_RND 3 /* lines */ 342 #define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 343 #define CVT_HSYNC_PERCENT 8 /* nominal hsync as percentage of line */ 344 345 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */ 346 #define CVT_CELL_GRAN 8 /* character cell granularity */ 347 #define CVT_M 600 /* blanking formula gradient */ 348 #define CVT_C 40 /* blanking formula offset */ 349 #define CVT_K 128 /* blanking formula scaling factor */ 350 #define CVT_J 20 /* blanking formula scaling factor */ 351 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J) 352 #define CVT_M_PRIME (CVT_K * CVT_M / 256) 353 354 /* Reduced Blanking */ 355 #define CVT_RB_MIN_V_BPORCH 7 /* lines */ 356 #define CVT_RB_V_FPORCH 3 /* lines */ 357 #define CVT_RB_MIN_V_BLANK 460 /* us */ 358 #define CVT_RB_H_SYNC 32 /* pixels */ 359 #define CVT_RB_H_BLANK 160 /* pixels */ 360 /* Reduce blanking Version 2 */ 361 #define CVT_RB_V2_H_BLANK 80 /* pixels */ 362 #define CVT_RB_MIN_V_FPORCH 3 /* lines */ 363 #define CVT_RB_V2_MIN_V_FPORCH 1 /* lines */ 364 #define CVT_RB_V_BPORCH 6 /* lines */ 365 366 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard 367 * @frame_height - the total height of the frame (including blanking) in lines. 368 * @hfreq - the horizontal frequency in Hz. 369 * @vsync - the height of the vertical sync in lines. 370 * @active_width - active width of image (does not include blanking). This 371 * information is needed only in case of version 2 of reduced blanking. 372 * In other cases, this parameter does not have any effect on timings. 373 * @polarities - the horizontal and vertical polarities (same as struct 374 * v4l2_bt_timings polarities). 375 * @interlaced - if this flag is true, it indicates interlaced format 376 * @fmt - the resulting timings. 377 * 378 * This function will attempt to detect if the given values correspond to a 379 * valid CVT format. If so, then it will return true, and fmt will be filled 380 * in with the found CVT timings. 381 */ 382 bool v4l2_detect_cvt(unsigned frame_height, 383 unsigned hfreq, 384 unsigned vsync, 385 unsigned active_width, 386 u32 polarities, 387 bool interlaced, 388 struct v4l2_dv_timings *fmt) 389 { 390 int v_fp, v_bp, h_fp, h_bp, hsync; 391 int frame_width, image_height, image_width; 392 bool reduced_blanking; 393 bool rb_v2 = false; 394 unsigned pix_clk; 395 396 if (vsync < 4 || vsync > 8) 397 return false; 398 399 if (polarities == V4L2_DV_VSYNC_POS_POL) 400 reduced_blanking = false; 401 else if (polarities == V4L2_DV_HSYNC_POS_POL) 402 reduced_blanking = true; 403 else 404 return false; 405 406 if (reduced_blanking && vsync == 8) 407 rb_v2 = true; 408 409 if (rb_v2 && active_width == 0) 410 return false; 411 412 if (!rb_v2 && vsync > 7) 413 return false; 414 415 if (hfreq == 0) 416 return false; 417 418 /* Vertical */ 419 if (reduced_blanking) { 420 if (rb_v2) { 421 v_bp = CVT_RB_V_BPORCH; 422 v_fp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1; 423 v_fp -= vsync + v_bp; 424 425 if (v_fp < CVT_RB_V2_MIN_V_FPORCH) 426 v_fp = CVT_RB_V2_MIN_V_FPORCH; 427 } else { 428 v_fp = CVT_RB_V_FPORCH; 429 v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1; 430 v_bp -= vsync + v_fp; 431 432 if (v_bp < CVT_RB_MIN_V_BPORCH) 433 v_bp = CVT_RB_MIN_V_BPORCH; 434 } 435 } else { 436 v_fp = CVT_MIN_V_PORCH_RND; 437 v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync; 438 439 if (v_bp < CVT_MIN_V_BPORCH) 440 v_bp = CVT_MIN_V_BPORCH; 441 } 442 443 if (interlaced) 444 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1; 445 else 446 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 447 448 if (image_height < 0) 449 return false; 450 451 /* Aspect ratio based on vsync */ 452 switch (vsync) { 453 case 4: 454 image_width = (image_height * 4) / 3; 455 break; 456 case 5: 457 image_width = (image_height * 16) / 9; 458 break; 459 case 6: 460 image_width = (image_height * 16) / 10; 461 break; 462 case 7: 463 /* special case */ 464 if (image_height == 1024) 465 image_width = (image_height * 5) / 4; 466 else if (image_height == 768) 467 image_width = (image_height * 15) / 9; 468 else 469 return false; 470 break; 471 case 8: 472 image_width = active_width; 473 break; 474 default: 475 return false; 476 } 477 478 if (!rb_v2) 479 image_width = image_width & ~7; 480 481 /* Horizontal */ 482 if (reduced_blanking) { 483 int h_blank; 484 int clk_gran; 485 486 h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK; 487 clk_gran = rb_v2 ? CVT_PXL_CLK_GRAN_RB_V2 : CVT_PXL_CLK_GRAN; 488 489 pix_clk = (image_width + h_blank) * hfreq; 490 pix_clk = (pix_clk / clk_gran) * clk_gran; 491 492 h_bp = h_blank / 2; 493 hsync = CVT_RB_H_SYNC; 494 h_fp = h_blank - h_bp - hsync; 495 496 frame_width = image_width + h_blank; 497 } else { 498 unsigned ideal_duty_cycle_per_myriad = 499 100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq; 500 int h_blank; 501 502 if (ideal_duty_cycle_per_myriad < 2000) 503 ideal_duty_cycle_per_myriad = 2000; 504 505 h_blank = image_width * ideal_duty_cycle_per_myriad / 506 (10000 - ideal_duty_cycle_per_myriad); 507 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN; 508 509 pix_clk = (image_width + h_blank) * hfreq; 510 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; 511 512 h_bp = h_blank / 2; 513 frame_width = image_width + h_blank; 514 515 hsync = frame_width * CVT_HSYNC_PERCENT / 100; 516 hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN; 517 h_fp = h_blank - hsync - h_bp; 518 } 519 520 fmt->type = V4L2_DV_BT_656_1120; 521 fmt->bt.polarities = polarities; 522 fmt->bt.width = image_width; 523 fmt->bt.height = image_height; 524 fmt->bt.hfrontporch = h_fp; 525 fmt->bt.vfrontporch = v_fp; 526 fmt->bt.hsync = hsync; 527 fmt->bt.vsync = vsync; 528 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 529 530 if (!interlaced) { 531 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 532 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE; 533 } else { 534 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp - 535 2 * vsync) / 2; 536 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp - 537 2 * vsync - fmt->bt.vbackporch; 538 fmt->bt.il_vfrontporch = v_fp; 539 fmt->bt.il_vsync = vsync; 540 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE; 541 fmt->bt.interlaced = V4L2_DV_INTERLACED; 542 } 543 544 fmt->bt.pixelclock = pix_clk; 545 fmt->bt.standards = V4L2_DV_BT_STD_CVT; 546 547 if (reduced_blanking) 548 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 549 550 return true; 551 } 552 EXPORT_SYMBOL_GPL(v4l2_detect_cvt); 553 554 /* 555 * GTF defines 556 * Based on Generalized Timing Formula Standard 557 * Version 1.1 September 2, 1999 558 */ 559 560 #define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 561 562 #define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 563 #define GTF_V_FP 1 /* vertical front porch (lines) */ 564 #define GTF_CELL_GRAN 8 /* character cell granularity */ 565 566 /* Default */ 567 #define GTF_D_M 600 /* blanking formula gradient */ 568 #define GTF_D_C 40 /* blanking formula offset */ 569 #define GTF_D_K 128 /* blanking formula scaling factor */ 570 #define GTF_D_J 20 /* blanking formula scaling factor */ 571 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J) 572 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256) 573 574 /* Secondary */ 575 #define GTF_S_M 3600 /* blanking formula gradient */ 576 #define GTF_S_C 40 /* blanking formula offset */ 577 #define GTF_S_K 128 /* blanking formula scaling factor */ 578 #define GTF_S_J 35 /* blanking formula scaling factor */ 579 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J) 580 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256) 581 582 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard 583 * @frame_height - the total height of the frame (including blanking) in lines. 584 * @hfreq - the horizontal frequency in Hz. 585 * @vsync - the height of the vertical sync in lines. 586 * @polarities - the horizontal and vertical polarities (same as struct 587 * v4l2_bt_timings polarities). 588 * @interlaced - if this flag is true, it indicates interlaced format 589 * @aspect - preferred aspect ratio. GTF has no method of determining the 590 * aspect ratio in order to derive the image width from the 591 * image height, so it has to be passed explicitly. Usually 592 * the native screen aspect ratio is used for this. If it 593 * is not filled in correctly, then 16:9 will be assumed. 594 * @fmt - the resulting timings. 595 * 596 * This function will attempt to detect if the given values correspond to a 597 * valid GTF format. If so, then it will return true, and fmt will be filled 598 * in with the found GTF timings. 599 */ 600 bool v4l2_detect_gtf(unsigned frame_height, 601 unsigned hfreq, 602 unsigned vsync, 603 u32 polarities, 604 bool interlaced, 605 struct v4l2_fract aspect, 606 struct v4l2_dv_timings *fmt) 607 { 608 int pix_clk; 609 int v_fp, v_bp, h_fp, hsync; 610 int frame_width, image_height, image_width; 611 bool default_gtf; 612 int h_blank; 613 614 if (vsync != 3) 615 return false; 616 617 if (polarities == V4L2_DV_VSYNC_POS_POL) 618 default_gtf = true; 619 else if (polarities == V4L2_DV_HSYNC_POS_POL) 620 default_gtf = false; 621 else 622 return false; 623 624 if (hfreq == 0) 625 return false; 626 627 /* Vertical */ 628 v_fp = GTF_V_FP; 629 v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync; 630 if (interlaced) 631 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1; 632 else 633 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 634 635 if (image_height < 0) 636 return false; 637 638 if (aspect.numerator == 0 || aspect.denominator == 0) { 639 aspect.numerator = 16; 640 aspect.denominator = 9; 641 } 642 image_width = ((image_height * aspect.numerator) / aspect.denominator); 643 image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1); 644 645 /* Horizontal */ 646 if (default_gtf) { 647 u64 num; 648 u32 den; 649 650 num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) - 651 ((u64)image_width * GTF_D_M_PRIME * 1000)); 652 den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) * 653 (2 * GTF_CELL_GRAN); 654 h_blank = div_u64((num + (den >> 1)), den); 655 h_blank *= (2 * GTF_CELL_GRAN); 656 } else { 657 u64 num; 658 u32 den; 659 660 num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) - 661 ((u64)image_width * GTF_S_M_PRIME * 1000)); 662 den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) * 663 (2 * GTF_CELL_GRAN); 664 h_blank = div_u64((num + (den >> 1)), den); 665 h_blank *= (2 * GTF_CELL_GRAN); 666 } 667 668 frame_width = image_width + h_blank; 669 670 pix_clk = (image_width + h_blank) * hfreq; 671 pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN; 672 673 hsync = (frame_width * 8 + 50) / 100; 674 hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN; 675 676 h_fp = h_blank / 2 - hsync; 677 678 fmt->type = V4L2_DV_BT_656_1120; 679 fmt->bt.polarities = polarities; 680 fmt->bt.width = image_width; 681 fmt->bt.height = image_height; 682 fmt->bt.hfrontporch = h_fp; 683 fmt->bt.vfrontporch = v_fp; 684 fmt->bt.hsync = hsync; 685 fmt->bt.vsync = vsync; 686 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 687 688 if (!interlaced) { 689 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 690 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE; 691 } else { 692 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp - 693 2 * vsync) / 2; 694 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp - 695 2 * vsync - fmt->bt.vbackporch; 696 fmt->bt.il_vfrontporch = v_fp; 697 fmt->bt.il_vsync = vsync; 698 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE; 699 fmt->bt.interlaced = V4L2_DV_INTERLACED; 700 } 701 702 fmt->bt.pixelclock = pix_clk; 703 fmt->bt.standards = V4L2_DV_BT_STD_GTF; 704 705 if (!default_gtf) 706 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 707 708 return true; 709 } 710 EXPORT_SYMBOL_GPL(v4l2_detect_gtf); 711 712 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes 713 * 0x15 and 0x16 from the EDID. 714 * @hor_landscape - byte 0x15 from the EDID. 715 * @vert_portrait - byte 0x16 from the EDID. 716 * 717 * Determines the aspect ratio from the EDID. 718 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2: 719 * "Horizontal and Vertical Screen Size or Aspect Ratio" 720 */ 721 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait) 722 { 723 struct v4l2_fract aspect = { 16, 9 }; 724 u8 ratio; 725 726 /* Nothing filled in, fallback to 16:9 */ 727 if (!hor_landscape && !vert_portrait) 728 return aspect; 729 /* Both filled in, so they are interpreted as the screen size in cm */ 730 if (hor_landscape && vert_portrait) { 731 aspect.numerator = hor_landscape; 732 aspect.denominator = vert_portrait; 733 return aspect; 734 } 735 /* Only one is filled in, so interpret them as a ratio: 736 (val + 99) / 100 */ 737 ratio = hor_landscape | vert_portrait; 738 /* Change some rounded values into the exact aspect ratio */ 739 if (ratio == 79) { 740 aspect.numerator = 16; 741 aspect.denominator = 9; 742 } else if (ratio == 34) { 743 aspect.numerator = 4; 744 aspect.denominator = 3; 745 } else if (ratio == 68) { 746 aspect.numerator = 15; 747 aspect.denominator = 9; 748 } else { 749 aspect.numerator = hor_landscape + 99; 750 aspect.denominator = 100; 751 } 752 if (hor_landscape) 753 return aspect; 754 /* The aspect ratio is for portrait, so swap numerator and denominator */ 755 swap(aspect.denominator, aspect.numerator); 756 return aspect; 757 } 758 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio); 759