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 (cap->standards && bt->standards && 169 !(bt->standards & cap->standards)) || 170 (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) || 171 (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE))) 172 return false; 173 return fnc == NULL || fnc(t, fnc_handle); 174 } 175 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings); 176 177 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t, 178 const struct v4l2_dv_timings_cap *cap, 179 v4l2_check_dv_timings_fnc fnc, 180 void *fnc_handle) 181 { 182 u32 i, idx; 183 184 memset(t->reserved, 0, sizeof(t->reserved)); 185 for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) { 186 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap, 187 fnc, fnc_handle) && 188 idx++ == t->index) { 189 t->timings = v4l2_dv_timings_presets[i]; 190 return 0; 191 } 192 } 193 return -EINVAL; 194 } 195 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap); 196 197 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t, 198 const struct v4l2_dv_timings_cap *cap, 199 unsigned pclock_delta, 200 v4l2_check_dv_timings_fnc fnc, 201 void *fnc_handle) 202 { 203 int i; 204 205 if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle)) 206 return false; 207 208 for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) { 209 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap, 210 fnc, fnc_handle) && 211 v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i, 212 pclock_delta)) { 213 *t = v4l2_dv_timings_presets[i]; 214 return true; 215 } 216 } 217 return false; 218 } 219 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap); 220 221 /** 222 * v4l2_match_dv_timings - check if two timings match 223 * @t1 - compare this v4l2_dv_timings struct... 224 * @t2 - with this struct. 225 * @pclock_delta - the allowed pixelclock deviation. 226 * 227 * Compare t1 with t2 with a given margin of error for the pixelclock. 228 */ 229 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1, 230 const struct v4l2_dv_timings *t2, 231 unsigned pclock_delta) 232 { 233 if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120) 234 return false; 235 if (t1->bt.width == t2->bt.width && 236 t1->bt.height == t2->bt.height && 237 t1->bt.interlaced == t2->bt.interlaced && 238 t1->bt.polarities == t2->bt.polarities && 239 t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta && 240 t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta && 241 t1->bt.hfrontporch == t2->bt.hfrontporch && 242 t1->bt.vfrontporch == t2->bt.vfrontporch && 243 t1->bt.vsync == t2->bt.vsync && 244 t1->bt.vbackporch == t2->bt.vbackporch && 245 (!t1->bt.interlaced || 246 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch && 247 t1->bt.il_vsync == t2->bt.il_vsync && 248 t1->bt.il_vbackporch == t2->bt.il_vbackporch))) 249 return true; 250 return false; 251 } 252 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings); 253 254 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix, 255 const struct v4l2_dv_timings *t, bool detailed) 256 { 257 const struct v4l2_bt_timings *bt = &t->bt; 258 u32 htot, vtot; 259 260 if (t->type != V4L2_DV_BT_656_1120) 261 return; 262 263 htot = V4L2_DV_BT_FRAME_WIDTH(bt); 264 vtot = V4L2_DV_BT_FRAME_HEIGHT(bt); 265 if (bt->interlaced) 266 vtot /= 2; 267 268 if (prefix == NULL) 269 prefix = ""; 270 271 pr_info("%s: %s%ux%u%s%u (%ux%u)\n", dev_prefix, prefix, 272 bt->width, bt->height, bt->interlaced ? "i" : "p", 273 (htot * vtot) > 0 ? ((u32)bt->pixelclock / (htot * vtot)) : 0, 274 htot, vtot); 275 276 if (!detailed) 277 return; 278 279 pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n", 280 dev_prefix, bt->hfrontporch, 281 (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-", 282 bt->hsync, bt->hbackporch); 283 pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n", 284 dev_prefix, bt->vfrontporch, 285 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-", 286 bt->vsync, bt->vbackporch); 287 if (bt->interlaced) 288 pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n", 289 dev_prefix, bt->il_vfrontporch, 290 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-", 291 bt->il_vsync, bt->il_vbackporch); 292 pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock); 293 pr_info("%s: flags (0x%x):%s%s%s%s%s\n", dev_prefix, bt->flags, 294 (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ? 295 " REDUCED_BLANKING" : "", 296 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ? 297 " CAN_REDUCE_FPS" : "", 298 (bt->flags & V4L2_DV_FL_REDUCED_FPS) ? 299 " REDUCED_FPS" : "", 300 (bt->flags & V4L2_DV_FL_HALF_LINE) ? 301 " HALF_LINE" : "", 302 (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ? 303 " CE_VIDEO" : ""); 304 pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards, 305 (bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "", 306 (bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "", 307 (bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "", 308 (bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : ""); 309 } 310 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings); 311 312 /* 313 * CVT defines 314 * Based on Coordinated Video Timings Standard 315 * version 1.1 September 10, 2003 316 */ 317 318 #define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 319 320 /* Normal blanking */ 321 #define CVT_MIN_V_BPORCH 7 /* lines */ 322 #define CVT_MIN_V_PORCH_RND 3 /* lines */ 323 #define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 324 #define CVT_HSYNC_PERCENT 8 /* nominal hsync as percentage of line */ 325 326 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */ 327 #define CVT_CELL_GRAN 8 /* character cell granularity */ 328 #define CVT_M 600 /* blanking formula gradient */ 329 #define CVT_C 40 /* blanking formula offset */ 330 #define CVT_K 128 /* blanking formula scaling factor */ 331 #define CVT_J 20 /* blanking formula scaling factor */ 332 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J) 333 #define CVT_M_PRIME (CVT_K * CVT_M / 256) 334 335 /* Reduced Blanking */ 336 #define CVT_RB_MIN_V_BPORCH 7 /* lines */ 337 #define CVT_RB_V_FPORCH 3 /* lines */ 338 #define CVT_RB_MIN_V_BLANK 460 /* us */ 339 #define CVT_RB_H_SYNC 32 /* pixels */ 340 #define CVT_RB_H_BPORCH 80 /* pixels */ 341 #define CVT_RB_H_BLANK 160 /* pixels */ 342 343 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard 344 * @frame_height - the total height of the frame (including blanking) in lines. 345 * @hfreq - the horizontal frequency in Hz. 346 * @vsync - the height of the vertical sync in lines. 347 * @polarities - the horizontal and vertical polarities (same as struct 348 * v4l2_bt_timings polarities). 349 * @interlaced - if this flag is true, it indicates interlaced format 350 * @fmt - the resulting timings. 351 * 352 * This function will attempt to detect if the given values correspond to a 353 * valid CVT format. If so, then it will return true, and fmt will be filled 354 * in with the found CVT timings. 355 * 356 * TODO: VESA defined a new version 2 of their reduced blanking 357 * formula. Support for that is currently missing in this CVT 358 * detection function. 359 */ 360 bool v4l2_detect_cvt(unsigned frame_height, unsigned hfreq, unsigned vsync, 361 u32 polarities, bool interlaced, struct v4l2_dv_timings *fmt) 362 { 363 int v_fp, v_bp, h_fp, h_bp, hsync; 364 int frame_width, image_height, image_width; 365 bool reduced_blanking; 366 unsigned pix_clk; 367 368 if (vsync < 4 || vsync > 7) 369 return false; 370 371 if (polarities == V4L2_DV_VSYNC_POS_POL) 372 reduced_blanking = false; 373 else if (polarities == V4L2_DV_HSYNC_POS_POL) 374 reduced_blanking = true; 375 else 376 return false; 377 378 if (hfreq == 0) 379 return false; 380 381 /* Vertical */ 382 if (reduced_blanking) { 383 v_fp = CVT_RB_V_FPORCH; 384 v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1; 385 v_bp -= vsync + v_fp; 386 387 if (v_bp < CVT_RB_MIN_V_BPORCH) 388 v_bp = CVT_RB_MIN_V_BPORCH; 389 } else { 390 v_fp = CVT_MIN_V_PORCH_RND; 391 v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync; 392 393 if (v_bp < CVT_MIN_V_BPORCH) 394 v_bp = CVT_MIN_V_BPORCH; 395 } 396 397 if (interlaced) 398 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1; 399 else 400 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 401 402 if (image_height < 0) 403 return false; 404 405 /* Aspect ratio based on vsync */ 406 switch (vsync) { 407 case 4: 408 image_width = (image_height * 4) / 3; 409 break; 410 case 5: 411 image_width = (image_height * 16) / 9; 412 break; 413 case 6: 414 image_width = (image_height * 16) / 10; 415 break; 416 case 7: 417 /* special case */ 418 if (image_height == 1024) 419 image_width = (image_height * 5) / 4; 420 else if (image_height == 768) 421 image_width = (image_height * 15) / 9; 422 else 423 return false; 424 break; 425 default: 426 return false; 427 } 428 429 image_width = image_width & ~7; 430 431 /* Horizontal */ 432 if (reduced_blanking) { 433 pix_clk = (image_width + CVT_RB_H_BLANK) * hfreq; 434 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; 435 436 h_bp = CVT_RB_H_BPORCH; 437 hsync = CVT_RB_H_SYNC; 438 h_fp = CVT_RB_H_BLANK - h_bp - hsync; 439 440 frame_width = image_width + CVT_RB_H_BLANK; 441 } else { 442 unsigned ideal_duty_cycle_per_myriad = 443 100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq; 444 int h_blank; 445 446 if (ideal_duty_cycle_per_myriad < 2000) 447 ideal_duty_cycle_per_myriad = 2000; 448 449 h_blank = image_width * ideal_duty_cycle_per_myriad / 450 (10000 - ideal_duty_cycle_per_myriad); 451 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN; 452 453 pix_clk = (image_width + h_blank) * hfreq; 454 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; 455 456 h_bp = h_blank / 2; 457 frame_width = image_width + h_blank; 458 459 hsync = frame_width * CVT_HSYNC_PERCENT / 100; 460 hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN; 461 h_fp = h_blank - hsync - h_bp; 462 } 463 464 fmt->type = V4L2_DV_BT_656_1120; 465 fmt->bt.polarities = polarities; 466 fmt->bt.width = image_width; 467 fmt->bt.height = image_height; 468 fmt->bt.hfrontporch = h_fp; 469 fmt->bt.vfrontporch = v_fp; 470 fmt->bt.hsync = hsync; 471 fmt->bt.vsync = vsync; 472 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 473 474 if (!interlaced) { 475 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 476 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE; 477 } else { 478 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp - 479 2 * vsync) / 2; 480 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp - 481 2 * vsync - fmt->bt.vbackporch; 482 fmt->bt.il_vfrontporch = v_fp; 483 fmt->bt.il_vsync = vsync; 484 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE; 485 fmt->bt.interlaced = V4L2_DV_INTERLACED; 486 } 487 488 fmt->bt.pixelclock = pix_clk; 489 fmt->bt.standards = V4L2_DV_BT_STD_CVT; 490 491 if (reduced_blanking) 492 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 493 494 return true; 495 } 496 EXPORT_SYMBOL_GPL(v4l2_detect_cvt); 497 498 /* 499 * GTF defines 500 * Based on Generalized Timing Formula Standard 501 * Version 1.1 September 2, 1999 502 */ 503 504 #define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 505 506 #define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 507 #define GTF_V_FP 1 /* vertical front porch (lines) */ 508 #define GTF_CELL_GRAN 8 /* character cell granularity */ 509 510 /* Default */ 511 #define GTF_D_M 600 /* blanking formula gradient */ 512 #define GTF_D_C 40 /* blanking formula offset */ 513 #define GTF_D_K 128 /* blanking formula scaling factor */ 514 #define GTF_D_J 20 /* blanking formula scaling factor */ 515 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J) 516 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256) 517 518 /* Secondary */ 519 #define GTF_S_M 3600 /* blanking formula gradient */ 520 #define GTF_S_C 40 /* blanking formula offset */ 521 #define GTF_S_K 128 /* blanking formula scaling factor */ 522 #define GTF_S_J 35 /* blanking formula scaling factor */ 523 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J) 524 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256) 525 526 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard 527 * @frame_height - the total height of the frame (including blanking) in lines. 528 * @hfreq - the horizontal frequency in Hz. 529 * @vsync - the height of the vertical sync in lines. 530 * @polarities - the horizontal and vertical polarities (same as struct 531 * v4l2_bt_timings polarities). 532 * @interlaced - if this flag is true, it indicates interlaced format 533 * @aspect - preferred aspect ratio. GTF has no method of determining the 534 * aspect ratio in order to derive the image width from the 535 * image height, so it has to be passed explicitly. Usually 536 * the native screen aspect ratio is used for this. If it 537 * is not filled in correctly, then 16:9 will be assumed. 538 * @fmt - the resulting timings. 539 * 540 * This function will attempt to detect if the given values correspond to a 541 * valid GTF format. If so, then it will return true, and fmt will be filled 542 * in with the found GTF timings. 543 */ 544 bool v4l2_detect_gtf(unsigned frame_height, 545 unsigned hfreq, 546 unsigned vsync, 547 u32 polarities, 548 bool interlaced, 549 struct v4l2_fract aspect, 550 struct v4l2_dv_timings *fmt) 551 { 552 int pix_clk; 553 int v_fp, v_bp, h_fp, hsync; 554 int frame_width, image_height, image_width; 555 bool default_gtf; 556 int h_blank; 557 558 if (vsync != 3) 559 return false; 560 561 if (polarities == V4L2_DV_VSYNC_POS_POL) 562 default_gtf = true; 563 else if (polarities == V4L2_DV_HSYNC_POS_POL) 564 default_gtf = false; 565 else 566 return false; 567 568 if (hfreq == 0) 569 return false; 570 571 /* Vertical */ 572 v_fp = GTF_V_FP; 573 v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync; 574 if (interlaced) 575 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1; 576 else 577 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 578 579 if (image_height < 0) 580 return false; 581 582 if (aspect.numerator == 0 || aspect.denominator == 0) { 583 aspect.numerator = 16; 584 aspect.denominator = 9; 585 } 586 image_width = ((image_height * aspect.numerator) / aspect.denominator); 587 image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1); 588 589 /* Horizontal */ 590 if (default_gtf) { 591 u64 num; 592 u32 den; 593 594 num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) - 595 ((u64)image_width * GTF_D_M_PRIME * 1000)); 596 den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) * 597 (2 * GTF_CELL_GRAN); 598 h_blank = div_u64((num + (den >> 1)), den); 599 h_blank *= (2 * GTF_CELL_GRAN); 600 } else { 601 u64 num; 602 u32 den; 603 604 num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) - 605 ((u64)image_width * GTF_S_M_PRIME * 1000)); 606 den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) * 607 (2 * GTF_CELL_GRAN); 608 h_blank = div_u64((num + (den >> 1)), den); 609 h_blank *= (2 * GTF_CELL_GRAN); 610 } 611 612 frame_width = image_width + h_blank; 613 614 pix_clk = (image_width + h_blank) * hfreq; 615 pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN; 616 617 hsync = (frame_width * 8 + 50) / 100; 618 hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN; 619 620 h_fp = h_blank / 2 - hsync; 621 622 fmt->type = V4L2_DV_BT_656_1120; 623 fmt->bt.polarities = polarities; 624 fmt->bt.width = image_width; 625 fmt->bt.height = image_height; 626 fmt->bt.hfrontporch = h_fp; 627 fmt->bt.vfrontporch = v_fp; 628 fmt->bt.hsync = hsync; 629 fmt->bt.vsync = vsync; 630 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 631 632 if (!interlaced) { 633 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 634 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE; 635 } else { 636 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp - 637 2 * vsync) / 2; 638 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp - 639 2 * vsync - fmt->bt.vbackporch; 640 fmt->bt.il_vfrontporch = v_fp; 641 fmt->bt.il_vsync = vsync; 642 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE; 643 fmt->bt.interlaced = V4L2_DV_INTERLACED; 644 } 645 646 fmt->bt.pixelclock = pix_clk; 647 fmt->bt.standards = V4L2_DV_BT_STD_GTF; 648 649 if (!default_gtf) 650 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 651 652 return true; 653 } 654 EXPORT_SYMBOL_GPL(v4l2_detect_gtf); 655 656 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes 657 * 0x15 and 0x16 from the EDID. 658 * @hor_landscape - byte 0x15 from the EDID. 659 * @vert_portrait - byte 0x16 from the EDID. 660 * 661 * Determines the aspect ratio from the EDID. 662 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2: 663 * "Horizontal and Vertical Screen Size or Aspect Ratio" 664 */ 665 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait) 666 { 667 struct v4l2_fract aspect = { 16, 9 }; 668 u32 tmp; 669 u8 ratio; 670 671 /* Nothing filled in, fallback to 16:9 */ 672 if (!hor_landscape && !vert_portrait) 673 return aspect; 674 /* Both filled in, so they are interpreted as the screen size in cm */ 675 if (hor_landscape && vert_portrait) { 676 aspect.numerator = hor_landscape; 677 aspect.denominator = vert_portrait; 678 return aspect; 679 } 680 /* Only one is filled in, so interpret them as a ratio: 681 (val + 99) / 100 */ 682 ratio = hor_landscape | vert_portrait; 683 /* Change some rounded values into the exact aspect ratio */ 684 if (ratio == 79) { 685 aspect.numerator = 16; 686 aspect.denominator = 9; 687 } else if (ratio == 34) { 688 aspect.numerator = 4; 689 aspect.denominator = 3; 690 } else if (ratio == 68) { 691 aspect.numerator = 15; 692 aspect.denominator = 9; 693 } else { 694 aspect.numerator = hor_landscape + 99; 695 aspect.denominator = 100; 696 } 697 if (hor_landscape) 698 return aspect; 699 /* The aspect ratio is for portrait, so swap numerator and denominator */ 700 tmp = aspect.denominator; 701 aspect.denominator = aspect.numerator; 702 aspect.numerator = tmp; 703 return aspect; 704 } 705 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio); 706