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