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 29MODULE_AUTHOR("Hans Verkuil"); 30MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions"); 31MODULE_LICENSE("GPL"); 32 33const struct v4l2_dv_timings v4l2_dv_timings_presets[] = { 34 V4L2_DV_BT_CEA_640X480P59_94, 35 V4L2_DV_BT_CEA_720X480I59_94, 36 V4L2_DV_BT_CEA_720X480P59_94, 37 V4L2_DV_BT_CEA_720X576I50, 38 V4L2_DV_BT_CEA_720X576P50, 39 V4L2_DV_BT_CEA_1280X720P24, 40 V4L2_DV_BT_CEA_1280X720P25, 41 V4L2_DV_BT_CEA_1280X720P30, 42 V4L2_DV_BT_CEA_1280X720P50, 43 V4L2_DV_BT_CEA_1280X720P60, 44 V4L2_DV_BT_CEA_1920X1080P24, 45 V4L2_DV_BT_CEA_1920X1080P25, 46 V4L2_DV_BT_CEA_1920X1080P30, 47 V4L2_DV_BT_CEA_1920X1080I50, 48 V4L2_DV_BT_CEA_1920X1080P50, 49 V4L2_DV_BT_CEA_1920X1080I60, 50 V4L2_DV_BT_CEA_1920X1080P60, 51 V4L2_DV_BT_DMT_640X350P85, 52 V4L2_DV_BT_DMT_640X400P85, 53 V4L2_DV_BT_DMT_720X400P85, 54 V4L2_DV_BT_DMT_640X480P72, 55 V4L2_DV_BT_DMT_640X480P75, 56 V4L2_DV_BT_DMT_640X480P85, 57 V4L2_DV_BT_DMT_800X600P56, 58 V4L2_DV_BT_DMT_800X600P60, 59 V4L2_DV_BT_DMT_800X600P72, 60 V4L2_DV_BT_DMT_800X600P75, 61 V4L2_DV_BT_DMT_800X600P85, 62 V4L2_DV_BT_DMT_800X600P120_RB, 63 V4L2_DV_BT_DMT_848X480P60, 64 V4L2_DV_BT_DMT_1024X768I43, 65 V4L2_DV_BT_DMT_1024X768P60, 66 V4L2_DV_BT_DMT_1024X768P70, 67 V4L2_DV_BT_DMT_1024X768P75, 68 V4L2_DV_BT_DMT_1024X768P85, 69 V4L2_DV_BT_DMT_1024X768P120_RB, 70 V4L2_DV_BT_DMT_1152X864P75, 71 V4L2_DV_BT_DMT_1280X768P60_RB, 72 V4L2_DV_BT_DMT_1280X768P60, 73 V4L2_DV_BT_DMT_1280X768P75, 74 V4L2_DV_BT_DMT_1280X768P85, 75 V4L2_DV_BT_DMT_1280X768P120_RB, 76 V4L2_DV_BT_DMT_1280X800P60_RB, 77 V4L2_DV_BT_DMT_1280X800P60, 78 V4L2_DV_BT_DMT_1280X800P75, 79 V4L2_DV_BT_DMT_1280X800P85, 80 V4L2_DV_BT_DMT_1280X800P120_RB, 81 V4L2_DV_BT_DMT_1280X960P60, 82 V4L2_DV_BT_DMT_1280X960P85, 83 V4L2_DV_BT_DMT_1280X960P120_RB, 84 V4L2_DV_BT_DMT_1280X1024P60, 85 V4L2_DV_BT_DMT_1280X1024P75, 86 V4L2_DV_BT_DMT_1280X1024P85, 87 V4L2_DV_BT_DMT_1280X1024P120_RB, 88 V4L2_DV_BT_DMT_1360X768P60, 89 V4L2_DV_BT_DMT_1360X768P120_RB, 90 V4L2_DV_BT_DMT_1366X768P60, 91 V4L2_DV_BT_DMT_1366X768P60_RB, 92 V4L2_DV_BT_DMT_1400X1050P60_RB, 93 V4L2_DV_BT_DMT_1400X1050P60, 94 V4L2_DV_BT_DMT_1400X1050P75, 95 V4L2_DV_BT_DMT_1400X1050P85, 96 V4L2_DV_BT_DMT_1400X1050P120_RB, 97 V4L2_DV_BT_DMT_1440X900P60_RB, 98 V4L2_DV_BT_DMT_1440X900P60, 99 V4L2_DV_BT_DMT_1440X900P75, 100 V4L2_DV_BT_DMT_1440X900P85, 101 V4L2_DV_BT_DMT_1440X900P120_RB, 102 V4L2_DV_BT_DMT_1600X900P60_RB, 103 V4L2_DV_BT_DMT_1600X1200P60, 104 V4L2_DV_BT_DMT_1600X1200P65, 105 V4L2_DV_BT_DMT_1600X1200P70, 106 V4L2_DV_BT_DMT_1600X1200P75, 107 V4L2_DV_BT_DMT_1600X1200P85, 108 V4L2_DV_BT_DMT_1600X1200P120_RB, 109 V4L2_DV_BT_DMT_1680X1050P60_RB, 110 V4L2_DV_BT_DMT_1680X1050P60, 111 V4L2_DV_BT_DMT_1680X1050P75, 112 V4L2_DV_BT_DMT_1680X1050P85, 113 V4L2_DV_BT_DMT_1680X1050P120_RB, 114 V4L2_DV_BT_DMT_1792X1344P60, 115 V4L2_DV_BT_DMT_1792X1344P75, 116 V4L2_DV_BT_DMT_1792X1344P120_RB, 117 V4L2_DV_BT_DMT_1856X1392P60, 118 V4L2_DV_BT_DMT_1856X1392P75, 119 V4L2_DV_BT_DMT_1856X1392P120_RB, 120 V4L2_DV_BT_DMT_1920X1200P60_RB, 121 V4L2_DV_BT_DMT_1920X1200P60, 122 V4L2_DV_BT_DMT_1920X1200P75, 123 V4L2_DV_BT_DMT_1920X1200P85, 124 V4L2_DV_BT_DMT_1920X1200P120_RB, 125 V4L2_DV_BT_DMT_1920X1440P60, 126 V4L2_DV_BT_DMT_1920X1440P75, 127 V4L2_DV_BT_DMT_1920X1440P120_RB, 128 V4L2_DV_BT_DMT_2048X1152P60_RB, 129 V4L2_DV_BT_DMT_2560X1600P60_RB, 130 V4L2_DV_BT_DMT_2560X1600P60, 131 V4L2_DV_BT_DMT_2560X1600P75, 132 V4L2_DV_BT_DMT_2560X1600P85, 133 V4L2_DV_BT_DMT_2560X1600P120_RB, 134 V4L2_DV_BT_CEA_3840X2160P24, 135 V4L2_DV_BT_CEA_3840X2160P25, 136 V4L2_DV_BT_CEA_3840X2160P30, 137 V4L2_DV_BT_CEA_3840X2160P50, 138 V4L2_DV_BT_CEA_3840X2160P60, 139 V4L2_DV_BT_CEA_4096X2160P24, 140 V4L2_DV_BT_CEA_4096X2160P25, 141 V4L2_DV_BT_CEA_4096X2160P30, 142 V4L2_DV_BT_CEA_4096X2160P50, 143 V4L2_DV_BT_DMT_4096X2160P59_94_RB, 144 V4L2_DV_BT_CEA_4096X2160P60, 145 { } 146}; 147EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets); 148 149bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t, 150 const struct v4l2_dv_timings_cap *dvcap, 151 v4l2_check_dv_timings_fnc fnc, 152 void *fnc_handle) 153{ 154 const struct v4l2_bt_timings *bt = &t->bt; 155 const struct v4l2_bt_timings_cap *cap = &dvcap->bt; 156 u32 caps = cap->capabilities; 157 158 if (t->type != V4L2_DV_BT_656_1120) 159 return false; 160 if (t->type != dvcap->type || 161 bt->height < cap->min_height || 162 bt->height > cap->max_height || 163 bt->width < cap->min_width || 164 bt->width > cap->max_width || 165 bt->pixelclock < cap->min_pixelclock || 166 bt->pixelclock > cap->max_pixelclock || 167 (cap->standards && bt->standards && 168 !(bt->standards & cap->standards)) || 169 (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) || 170 (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE))) 171 return false; 172 return fnc == NULL || fnc(t, fnc_handle); 173} 174EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings); 175 176int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t, 177 const struct v4l2_dv_timings_cap *cap, 178 v4l2_check_dv_timings_fnc fnc, 179 void *fnc_handle) 180{ 181 u32 i, idx; 182 183 memset(t->reserved, 0, sizeof(t->reserved)); 184 for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) { 185 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap, 186 fnc, fnc_handle) && 187 idx++ == t->index) { 188 t->timings = v4l2_dv_timings_presets[i]; 189 return 0; 190 } 191 } 192 return -EINVAL; 193} 194EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap); 195 196bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t, 197 const struct v4l2_dv_timings_cap *cap, 198 unsigned pclock_delta, 199 v4l2_check_dv_timings_fnc fnc, 200 void *fnc_handle) 201{ 202 int i; 203 204 if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle)) 205 return false; 206 207 for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) { 208 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap, 209 fnc, fnc_handle) && 210 v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i, 211 pclock_delta)) { 212 *t = v4l2_dv_timings_presets[i]; 213 return true; 214 } 215 } 216 return false; 217} 218EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap); 219 220/** 221 * v4l2_match_dv_timings - check if two timings match 222 * @t1 - compare this v4l2_dv_timings struct... 223 * @t2 - with this struct. 224 * @pclock_delta - the allowed pixelclock deviation. 225 * 226 * Compare t1 with t2 with a given margin of error for the pixelclock. 227 */ 228bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1, 229 const struct v4l2_dv_timings *t2, 230 unsigned pclock_delta) 231{ 232 if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120) 233 return false; 234 if (t1->bt.width == t2->bt.width && 235 t1->bt.height == t2->bt.height && 236 t1->bt.interlaced == t2->bt.interlaced && 237 t1->bt.polarities == t2->bt.polarities && 238 t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta && 239 t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta && 240 t1->bt.hfrontporch == t2->bt.hfrontporch && 241 t1->bt.vfrontporch == t2->bt.vfrontporch && 242 t1->bt.vsync == t2->bt.vsync && 243 t1->bt.vbackporch == t2->bt.vbackporch && 244 (!t1->bt.interlaced || 245 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch && 246 t1->bt.il_vsync == t2->bt.il_vsync && 247 t1->bt.il_vbackporch == t2->bt.il_vbackporch))) 248 return true; 249 return false; 250} 251EXPORT_SYMBOL_GPL(v4l2_match_dv_timings); 252 253void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix, 254 const struct v4l2_dv_timings *t, bool detailed) 255{ 256 const struct v4l2_bt_timings *bt = &t->bt; 257 u32 htot, vtot; 258 259 if (t->type != V4L2_DV_BT_656_1120) 260 return; 261 262 htot = V4L2_DV_BT_FRAME_WIDTH(bt); 263 vtot = V4L2_DV_BT_FRAME_HEIGHT(bt); 264 265 if (prefix == NULL) 266 prefix = ""; 267 268 pr_info("%s: %s%ux%u%s%u (%ux%u)\n", dev_prefix, prefix, 269 bt->width, bt->height, bt->interlaced ? "i" : "p", 270 (htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0, 271 htot, vtot); 272 273 if (!detailed) 274 return; 275 276 pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n", 277 dev_prefix, bt->hfrontporch, 278 (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-", 279 bt->hsync, bt->hbackporch); 280 pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n", 281 dev_prefix, bt->vfrontporch, 282 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-", 283 bt->vsync, bt->vbackporch); 284 pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock); 285 pr_info("%s: flags (0x%x):%s%s%s%s%s\n", dev_prefix, bt->flags, 286 (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ? 287 " REDUCED_BLANKING" : "", 288 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ? 289 " CAN_REDUCE_FPS" : "", 290 (bt->flags & V4L2_DV_FL_REDUCED_FPS) ? 291 " REDUCED_FPS" : "", 292 (bt->flags & V4L2_DV_FL_HALF_LINE) ? 293 " HALF_LINE" : "", 294 (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ? 295 " CE_VIDEO" : ""); 296 pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards, 297 (bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "", 298 (bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "", 299 (bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "", 300 (bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : ""); 301} 302EXPORT_SYMBOL_GPL(v4l2_print_dv_timings); 303 304/* 305 * CVT defines 306 * Based on Coordinated Video Timings Standard 307 * version 1.1 September 10, 2003 308 */ 309 310#define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 311 312/* Normal blanking */ 313#define CVT_MIN_V_BPORCH 7 /* lines */ 314#define CVT_MIN_V_PORCH_RND 3 /* lines */ 315#define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 316 317/* Normal blanking for CVT uses GTF to calculate horizontal blanking */ 318#define CVT_CELL_GRAN 8 /* character cell granularity */ 319#define CVT_M 600 /* blanking formula gradient */ 320#define CVT_C 40 /* blanking formula offset */ 321#define CVT_K 128 /* blanking formula scaling factor */ 322#define CVT_J 20 /* blanking formula scaling factor */ 323#define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J) 324#define CVT_M_PRIME (CVT_K * CVT_M / 256) 325 326/* Reduced Blanking */ 327#define CVT_RB_MIN_V_BPORCH 7 /* lines */ 328#define CVT_RB_V_FPORCH 3 /* lines */ 329#define CVT_RB_MIN_V_BLANK 460 /* us */ 330#define CVT_RB_H_SYNC 32 /* pixels */ 331#define CVT_RB_H_BPORCH 80 /* pixels */ 332#define CVT_RB_H_BLANK 160 /* pixels */ 333 334/** v4l2_detect_cvt - detect if the given timings follow the CVT standard 335 * @frame_height - the total height of the frame (including blanking) in lines. 336 * @hfreq - the horizontal frequency in Hz. 337 * @vsync - the height of the vertical sync in lines. 338 * @polarities - the horizontal and vertical polarities (same as struct 339 * v4l2_bt_timings polarities). 340 * @fmt - the resulting timings. 341 * 342 * This function will attempt to detect if the given values correspond to a 343 * valid CVT format. If so, then it will return true, and fmt will be filled 344 * in with the found CVT timings. 345 * 346 * TODO: VESA defined a new version 2 of their reduced blanking 347 * formula. Support for that is currently missing in this CVT 348 * detection function. 349 */ 350bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, 351 u32 polarities, struct v4l2_dv_timings *fmt) 352{ 353 int v_fp, v_bp, h_fp, h_bp, hsync; 354 int frame_width, image_height, image_width; 355 bool reduced_blanking; 356 unsigned pix_clk; 357 358 if (vsync < 4 || vsync > 7) 359 return false; 360 361 if (polarities == V4L2_DV_VSYNC_POS_POL) 362 reduced_blanking = false; 363 else if (polarities == V4L2_DV_HSYNC_POS_POL) 364 reduced_blanking = true; 365 else 366 return false; 367 368 /* Vertical */ 369 if (reduced_blanking) { 370 v_fp = CVT_RB_V_FPORCH; 371 v_bp = (CVT_RB_MIN_V_BLANK * hfreq + 1999999) / 1000000; 372 v_bp -= vsync + v_fp; 373 374 if (v_bp < CVT_RB_MIN_V_BPORCH) 375 v_bp = CVT_RB_MIN_V_BPORCH; 376 } else { 377 v_fp = CVT_MIN_V_PORCH_RND; 378 v_bp = (CVT_MIN_VSYNC_BP * hfreq + 1999999) / 1000000 - vsync; 379 380 if (v_bp < CVT_MIN_V_BPORCH) 381 v_bp = CVT_MIN_V_BPORCH; 382 } 383 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 384 385 /* Aspect ratio based on vsync */ 386 switch (vsync) { 387 case 4: 388 image_width = (image_height * 4) / 3; 389 break; 390 case 5: 391 image_width = (image_height * 16) / 9; 392 break; 393 case 6: 394 image_width = (image_height * 16) / 10; 395 break; 396 case 7: 397 /* special case */ 398 if (image_height == 1024) 399 image_width = (image_height * 5) / 4; 400 else if (image_height == 768) 401 image_width = (image_height * 15) / 9; 402 else 403 return false; 404 break; 405 default: 406 return false; 407 } 408 409 image_width = image_width & ~7; 410 411 /* Horizontal */ 412 if (reduced_blanking) { 413 pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq; 414 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; 415 416 h_bp = CVT_RB_H_BPORCH; 417 hsync = CVT_RB_H_SYNC; 418 h_fp = CVT_RB_H_BLANK - h_bp - hsync; 419 420 frame_width = image_width + CVT_RB_H_BLANK; 421 } else { 422 unsigned ideal_duty_cycle_per_myriad = 423 100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq; 424 int h_blank; 425 426 if (ideal_duty_cycle_per_myriad < 2000) 427 ideal_duty_cycle_per_myriad = 2000; 428 429 h_blank = image_width * ideal_duty_cycle_per_myriad / 430 (10000 - ideal_duty_cycle_per_myriad); 431 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN; 432 433 pix_clk = (image_width + h_blank) * hfreq; 434 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; 435 436 h_bp = h_blank / 2; 437 frame_width = image_width + h_blank; 438 439 hsync = (frame_width * 8 + 50) / 100; 440 hsync = hsync - hsync % CVT_CELL_GRAN; 441 h_fp = h_blank - hsync - h_bp; 442 } 443 444 fmt->type = V4L2_DV_BT_656_1120; 445 fmt->bt.polarities = polarities; 446 fmt->bt.width = image_width; 447 fmt->bt.height = image_height; 448 fmt->bt.hfrontporch = h_fp; 449 fmt->bt.vfrontporch = v_fp; 450 fmt->bt.hsync = hsync; 451 fmt->bt.vsync = vsync; 452 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 453 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 454 fmt->bt.pixelclock = pix_clk; 455 fmt->bt.standards = V4L2_DV_BT_STD_CVT; 456 if (reduced_blanking) 457 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 458 return true; 459} 460EXPORT_SYMBOL_GPL(v4l2_detect_cvt); 461 462/* 463 * GTF defines 464 * Based on Generalized Timing Formula Standard 465 * Version 1.1 September 2, 1999 466 */ 467 468#define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 469 470#define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 471#define GTF_V_FP 1 /* vertical front porch (lines) */ 472#define GTF_CELL_GRAN 8 /* character cell granularity */ 473 474/* Default */ 475#define GTF_D_M 600 /* blanking formula gradient */ 476#define GTF_D_C 40 /* blanking formula offset */ 477#define GTF_D_K 128 /* blanking formula scaling factor */ 478#define GTF_D_J 20 /* blanking formula scaling factor */ 479#define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J) 480#define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256) 481 482/* Secondary */ 483#define GTF_S_M 3600 /* blanking formula gradient */ 484#define GTF_S_C 40 /* blanking formula offset */ 485#define GTF_S_K 128 /* blanking formula scaling factor */ 486#define GTF_S_J 35 /* blanking formula scaling factor */ 487#define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J) 488#define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256) 489 490/** v4l2_detect_gtf - detect if the given timings follow the GTF standard 491 * @frame_height - the total height of the frame (including blanking) in lines. 492 * @hfreq - the horizontal frequency in Hz. 493 * @vsync - the height of the vertical sync in lines. 494 * @polarities - the horizontal and vertical polarities (same as struct 495 * v4l2_bt_timings polarities). 496 * @aspect - preferred aspect ratio. GTF has no method of determining the 497 * aspect ratio in order to derive the image width from the 498 * image height, so it has to be passed explicitly. Usually 499 * the native screen aspect ratio is used for this. If it 500 * is not filled in correctly, then 16:9 will be assumed. 501 * @fmt - the resulting timings. 502 * 503 * This function will attempt to detect if the given values correspond to a 504 * valid GTF format. If so, then it will return true, and fmt will be filled 505 * in with the found GTF timings. 506 */ 507bool v4l2_detect_gtf(unsigned frame_height, 508 unsigned hfreq, 509 unsigned vsync, 510 u32 polarities, 511 struct v4l2_fract aspect, 512 struct v4l2_dv_timings *fmt) 513{ 514 int pix_clk; 515 int v_fp, v_bp, h_fp, hsync; 516 int frame_width, image_height, image_width; 517 bool default_gtf; 518 int h_blank; 519 520 if (vsync != 3) 521 return false; 522 523 if (polarities == V4L2_DV_VSYNC_POS_POL) 524 default_gtf = true; 525 else if (polarities == V4L2_DV_HSYNC_POS_POL) 526 default_gtf = false; 527 else 528 return false; 529 530 /* Vertical */ 531 v_fp = GTF_V_FP; 532 v_bp = (GTF_MIN_VSYNC_BP * hfreq + 999999) / 1000000 - vsync; 533 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 534 535 if (aspect.numerator == 0 || aspect.denominator == 0) { 536 aspect.numerator = 16; 537 aspect.denominator = 9; 538 } 539 image_width = ((image_height * aspect.numerator) / aspect.denominator); 540 image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1); 541 542 /* Horizontal */ 543 if (default_gtf) 544 h_blank = ((image_width * GTF_D_C_PRIME * hfreq) - 545 (image_width * GTF_D_M_PRIME * 1000) + 546 (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) / 2) / 547 (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000); 548 else 549 h_blank = ((image_width * GTF_S_C_PRIME * hfreq) - 550 (image_width * GTF_S_M_PRIME * 1000) + 551 (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) / 2) / 552 (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000); 553 554 h_blank = h_blank - h_blank % (2 * GTF_CELL_GRAN); 555 frame_width = image_width + h_blank; 556 557 pix_clk = (image_width + h_blank) * hfreq; 558 pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN; 559 560 hsync = (frame_width * 8 + 50) / 100; 561 hsync = hsync - hsync % GTF_CELL_GRAN; 562 563 h_fp = h_blank / 2 - hsync; 564 565 fmt->type = V4L2_DV_BT_656_1120; 566 fmt->bt.polarities = polarities; 567 fmt->bt.width = image_width; 568 fmt->bt.height = image_height; 569 fmt->bt.hfrontporch = h_fp; 570 fmt->bt.vfrontporch = v_fp; 571 fmt->bt.hsync = hsync; 572 fmt->bt.vsync = vsync; 573 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 574 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 575 fmt->bt.pixelclock = pix_clk; 576 fmt->bt.standards = V4L2_DV_BT_STD_GTF; 577 if (!default_gtf) 578 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 579 return true; 580} 581EXPORT_SYMBOL_GPL(v4l2_detect_gtf); 582 583/** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes 584 * 0x15 and 0x16 from the EDID. 585 * @hor_landscape - byte 0x15 from the EDID. 586 * @vert_portrait - byte 0x16 from the EDID. 587 * 588 * Determines the aspect ratio from the EDID. 589 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2: 590 * "Horizontal and Vertical Screen Size or Aspect Ratio" 591 */ 592struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait) 593{ 594 struct v4l2_fract aspect = { 16, 9 }; 595 u32 tmp; 596 u8 ratio; 597 598 /* Nothing filled in, fallback to 16:9 */ 599 if (!hor_landscape && !vert_portrait) 600 return aspect; 601 /* Both filled in, so they are interpreted as the screen size in cm */ 602 if (hor_landscape && vert_portrait) { 603 aspect.numerator = hor_landscape; 604 aspect.denominator = vert_portrait; 605 return aspect; 606 } 607 /* Only one is filled in, so interpret them as a ratio: 608 (val + 99) / 100 */ 609 ratio = hor_landscape | vert_portrait; 610 /* Change some rounded values into the exact aspect ratio */ 611 if (ratio == 79) { 612 aspect.numerator = 16; 613 aspect.denominator = 9; 614 } else if (ratio == 34) { 615 aspect.numerator = 4; 616 aspect.denominator = 3; 617 } else if (ratio == 68) { 618 aspect.numerator = 15; 619 aspect.denominator = 9; 620 } else { 621 aspect.numerator = hor_landscape + 99; 622 aspect.denominator = 100; 623 } 624 if (hor_landscape) 625 return aspect; 626 /* The aspect ratio is for portrait, so swap numerator and denominator */ 627 tmp = aspect.denominator; 628 aspect.denominator = aspect.numerator; 629 aspect.numerator = tmp; 630 return aspect; 631} 632EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio); 633