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, false)) { 213 u32 flags = t->bt.flags & V4L2_DV_FL_REDUCED_FPS; 214 215 *t = v4l2_dv_timings_presets[i]; 216 if (can_reduce_fps(&t->bt)) 217 t->bt.flags |= flags; 218 219 return true; 220 } 221 } 222 return false; 223 } 224 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap); 225 226 /** 227 * v4l2_match_dv_timings - check if two timings match 228 * @t1 - compare this v4l2_dv_timings struct... 229 * @t2 - with this struct. 230 * @pclock_delta - the allowed pixelclock deviation. 231 * @match_reduced_fps - if true, then fail if V4L2_DV_FL_REDUCED_FPS does not 232 * match. 233 * 234 * Compare t1 with t2 with a given margin of error for the pixelclock. 235 */ 236 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1, 237 const struct v4l2_dv_timings *t2, 238 unsigned pclock_delta, bool match_reduced_fps) 239 { 240 if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120) 241 return false; 242 if (t1->bt.width == t2->bt.width && 243 t1->bt.height == t2->bt.height && 244 t1->bt.interlaced == t2->bt.interlaced && 245 t1->bt.polarities == t2->bt.polarities && 246 t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta && 247 t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta && 248 t1->bt.hfrontporch == t2->bt.hfrontporch && 249 t1->bt.hsync == t2->bt.hsync && 250 t1->bt.hbackporch == t2->bt.hbackporch && 251 t1->bt.vfrontporch == t2->bt.vfrontporch && 252 t1->bt.vsync == t2->bt.vsync && 253 t1->bt.vbackporch == t2->bt.vbackporch && 254 (!match_reduced_fps || 255 (t1->bt.flags & V4L2_DV_FL_REDUCED_FPS) == 256 (t2->bt.flags & V4L2_DV_FL_REDUCED_FPS)) && 257 (!t1->bt.interlaced || 258 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch && 259 t1->bt.il_vsync == t2->bt.il_vsync && 260 t1->bt.il_vbackporch == t2->bt.il_vbackporch))) 261 return true; 262 return false; 263 } 264 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings); 265 266 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix, 267 const struct v4l2_dv_timings *t, bool detailed) 268 { 269 const struct v4l2_bt_timings *bt = &t->bt; 270 u32 htot, vtot; 271 u32 fps; 272 273 if (t->type != V4L2_DV_BT_656_1120) 274 return; 275 276 htot = V4L2_DV_BT_FRAME_WIDTH(bt); 277 vtot = V4L2_DV_BT_FRAME_HEIGHT(bt); 278 if (bt->interlaced) 279 vtot /= 2; 280 281 fps = (htot * vtot) > 0 ? div_u64((100 * (u64)bt->pixelclock), 282 (htot * vtot)) : 0; 283 284 if (prefix == NULL) 285 prefix = ""; 286 287 pr_info("%s: %s%ux%u%s%u.%u (%ux%u)\n", dev_prefix, prefix, 288 bt->width, bt->height, bt->interlaced ? "i" : "p", 289 fps / 100, fps % 100, htot, vtot); 290 291 if (!detailed) 292 return; 293 294 pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n", 295 dev_prefix, bt->hfrontporch, 296 (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-", 297 bt->hsync, bt->hbackporch); 298 pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n", 299 dev_prefix, bt->vfrontporch, 300 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-", 301 bt->vsync, bt->vbackporch); 302 if (bt->interlaced) 303 pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n", 304 dev_prefix, bt->il_vfrontporch, 305 (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-", 306 bt->il_vsync, bt->il_vbackporch); 307 pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock); 308 pr_info("%s: flags (0x%x):%s%s%s%s%s%s\n", dev_prefix, bt->flags, 309 (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ? 310 " REDUCED_BLANKING" : "", 311 ((bt->flags & V4L2_DV_FL_REDUCED_BLANKING) && 312 bt->vsync == 8) ? " (V2)" : "", 313 (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ? 314 " CAN_REDUCE_FPS" : "", 315 (bt->flags & V4L2_DV_FL_REDUCED_FPS) ? 316 " REDUCED_FPS" : "", 317 (bt->flags & V4L2_DV_FL_HALF_LINE) ? 318 " HALF_LINE" : "", 319 (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ? 320 " CE_VIDEO" : ""); 321 pr_info("%s: standards (0x%x):%s%s%s%s\n", dev_prefix, bt->standards, 322 (bt->standards & V4L2_DV_BT_STD_CEA861) ? " CEA" : "", 323 (bt->standards & V4L2_DV_BT_STD_DMT) ? " DMT" : "", 324 (bt->standards & V4L2_DV_BT_STD_CVT) ? " CVT" : "", 325 (bt->standards & V4L2_DV_BT_STD_GTF) ? " GTF" : ""); 326 } 327 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings); 328 329 /* 330 * CVT defines 331 * Based on Coordinated Video Timings Standard 332 * version 1.1 September 10, 2003 333 */ 334 335 #define CVT_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 336 #define CVT_PXL_CLK_GRAN_RB_V2 1000 /* granularity for reduced blanking v2*/ 337 338 /* Normal blanking */ 339 #define CVT_MIN_V_BPORCH 7 /* lines */ 340 #define CVT_MIN_V_PORCH_RND 3 /* lines */ 341 #define CVT_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 342 #define CVT_HSYNC_PERCENT 8 /* nominal hsync as percentage of line */ 343 344 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */ 345 #define CVT_CELL_GRAN 8 /* character cell granularity */ 346 #define CVT_M 600 /* blanking formula gradient */ 347 #define CVT_C 40 /* blanking formula offset */ 348 #define CVT_K 128 /* blanking formula scaling factor */ 349 #define CVT_J 20 /* blanking formula scaling factor */ 350 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J) 351 #define CVT_M_PRIME (CVT_K * CVT_M / 256) 352 353 /* Reduced Blanking */ 354 #define CVT_RB_MIN_V_BPORCH 7 /* lines */ 355 #define CVT_RB_V_FPORCH 3 /* lines */ 356 #define CVT_RB_MIN_V_BLANK 460 /* us */ 357 #define CVT_RB_H_SYNC 32 /* pixels */ 358 #define CVT_RB_H_BLANK 160 /* pixels */ 359 /* Reduce blanking Version 2 */ 360 #define CVT_RB_V2_H_BLANK 80 /* pixels */ 361 #define CVT_RB_MIN_V_FPORCH 3 /* lines */ 362 #define CVT_RB_V2_MIN_V_FPORCH 1 /* lines */ 363 #define CVT_RB_V_BPORCH 6 /* lines */ 364 365 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard 366 * @frame_height - the total height of the frame (including blanking) in lines. 367 * @hfreq - the horizontal frequency in Hz. 368 * @vsync - the height of the vertical sync in lines. 369 * @active_width - active width of image (does not include blanking). This 370 * information is needed only in case of version 2 of reduced blanking. 371 * In other cases, this parameter does not have any effect on timings. 372 * @polarities - the horizontal and vertical polarities (same as struct 373 * v4l2_bt_timings polarities). 374 * @interlaced - if this flag is true, it indicates interlaced format 375 * @fmt - the resulting timings. 376 * 377 * This function will attempt to detect if the given values correspond to a 378 * valid CVT format. If so, then it will return true, and fmt will be filled 379 * in with the found CVT timings. 380 */ 381 bool v4l2_detect_cvt(unsigned frame_height, 382 unsigned hfreq, 383 unsigned vsync, 384 unsigned active_width, 385 u32 polarities, 386 bool interlaced, 387 struct v4l2_dv_timings *fmt) 388 { 389 int v_fp, v_bp, h_fp, h_bp, hsync; 390 int frame_width, image_height, image_width; 391 bool reduced_blanking; 392 bool rb_v2 = false; 393 unsigned pix_clk; 394 395 if (vsync < 4 || vsync > 8) 396 return false; 397 398 if (polarities == V4L2_DV_VSYNC_POS_POL) 399 reduced_blanking = false; 400 else if (polarities == V4L2_DV_HSYNC_POS_POL) 401 reduced_blanking = true; 402 else 403 return false; 404 405 if (reduced_blanking && vsync == 8) 406 rb_v2 = true; 407 408 if (rb_v2 && active_width == 0) 409 return false; 410 411 if (!rb_v2 && vsync > 7) 412 return false; 413 414 if (hfreq == 0) 415 return false; 416 417 /* Vertical */ 418 if (reduced_blanking) { 419 if (rb_v2) { 420 v_bp = CVT_RB_V_BPORCH; 421 v_fp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1; 422 v_fp -= vsync + v_bp; 423 424 if (v_fp < CVT_RB_V2_MIN_V_FPORCH) 425 v_fp = CVT_RB_V2_MIN_V_FPORCH; 426 } else { 427 v_fp = CVT_RB_V_FPORCH; 428 v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1; 429 v_bp -= vsync + v_fp; 430 431 if (v_bp < CVT_RB_MIN_V_BPORCH) 432 v_bp = CVT_RB_MIN_V_BPORCH; 433 } 434 } else { 435 v_fp = CVT_MIN_V_PORCH_RND; 436 v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync; 437 438 if (v_bp < CVT_MIN_V_BPORCH) 439 v_bp = CVT_MIN_V_BPORCH; 440 } 441 442 if (interlaced) 443 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1; 444 else 445 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 446 447 if (image_height < 0) 448 return false; 449 450 /* Aspect ratio based on vsync */ 451 switch (vsync) { 452 case 4: 453 image_width = (image_height * 4) / 3; 454 break; 455 case 5: 456 image_width = (image_height * 16) / 9; 457 break; 458 case 6: 459 image_width = (image_height * 16) / 10; 460 break; 461 case 7: 462 /* special case */ 463 if (image_height == 1024) 464 image_width = (image_height * 5) / 4; 465 else if (image_height == 768) 466 image_width = (image_height * 15) / 9; 467 else 468 return false; 469 break; 470 case 8: 471 image_width = active_width; 472 break; 473 default: 474 return false; 475 } 476 477 if (!rb_v2) 478 image_width = image_width & ~7; 479 480 /* Horizontal */ 481 if (reduced_blanking) { 482 int h_blank; 483 int clk_gran; 484 485 h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK; 486 clk_gran = rb_v2 ? CVT_PXL_CLK_GRAN_RB_V2 : CVT_PXL_CLK_GRAN; 487 488 pix_clk = (image_width + h_blank) * hfreq; 489 pix_clk = (pix_clk / clk_gran) * clk_gran; 490 491 h_bp = h_blank / 2; 492 hsync = CVT_RB_H_SYNC; 493 h_fp = h_blank - h_bp - hsync; 494 495 frame_width = image_width + h_blank; 496 } else { 497 unsigned ideal_duty_cycle_per_myriad = 498 100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq; 499 int h_blank; 500 501 if (ideal_duty_cycle_per_myriad < 2000) 502 ideal_duty_cycle_per_myriad = 2000; 503 504 h_blank = image_width * ideal_duty_cycle_per_myriad / 505 (10000 - ideal_duty_cycle_per_myriad); 506 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN; 507 508 pix_clk = (image_width + h_blank) * hfreq; 509 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN; 510 511 h_bp = h_blank / 2; 512 frame_width = image_width + h_blank; 513 514 hsync = frame_width * CVT_HSYNC_PERCENT / 100; 515 hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN; 516 h_fp = h_blank - hsync - h_bp; 517 } 518 519 fmt->type = V4L2_DV_BT_656_1120; 520 fmt->bt.polarities = polarities; 521 fmt->bt.width = image_width; 522 fmt->bt.height = image_height; 523 fmt->bt.hfrontporch = h_fp; 524 fmt->bt.vfrontporch = v_fp; 525 fmt->bt.hsync = hsync; 526 fmt->bt.vsync = vsync; 527 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 528 529 if (!interlaced) { 530 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 531 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE; 532 } else { 533 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp - 534 2 * vsync) / 2; 535 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp - 536 2 * vsync - fmt->bt.vbackporch; 537 fmt->bt.il_vfrontporch = v_fp; 538 fmt->bt.il_vsync = vsync; 539 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE; 540 fmt->bt.interlaced = V4L2_DV_INTERLACED; 541 } 542 543 fmt->bt.pixelclock = pix_clk; 544 fmt->bt.standards = V4L2_DV_BT_STD_CVT; 545 546 if (reduced_blanking) 547 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 548 549 return true; 550 } 551 EXPORT_SYMBOL_GPL(v4l2_detect_cvt); 552 553 /* 554 * GTF defines 555 * Based on Generalized Timing Formula Standard 556 * Version 1.1 September 2, 1999 557 */ 558 559 #define GTF_PXL_CLK_GRAN 250000 /* pixel clock granularity */ 560 561 #define GTF_MIN_VSYNC_BP 550 /* min time of vsync + back porch (us) */ 562 #define GTF_V_FP 1 /* vertical front porch (lines) */ 563 #define GTF_CELL_GRAN 8 /* character cell granularity */ 564 565 /* Default */ 566 #define GTF_D_M 600 /* blanking formula gradient */ 567 #define GTF_D_C 40 /* blanking formula offset */ 568 #define GTF_D_K 128 /* blanking formula scaling factor */ 569 #define GTF_D_J 20 /* blanking formula scaling factor */ 570 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J) 571 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256) 572 573 /* Secondary */ 574 #define GTF_S_M 3600 /* blanking formula gradient */ 575 #define GTF_S_C 40 /* blanking formula offset */ 576 #define GTF_S_K 128 /* blanking formula scaling factor */ 577 #define GTF_S_J 35 /* blanking formula scaling factor */ 578 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J) 579 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256) 580 581 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard 582 * @frame_height - the total height of the frame (including blanking) in lines. 583 * @hfreq - the horizontal frequency in Hz. 584 * @vsync - the height of the vertical sync in lines. 585 * @polarities - the horizontal and vertical polarities (same as struct 586 * v4l2_bt_timings polarities). 587 * @interlaced - if this flag is true, it indicates interlaced format 588 * @aspect - preferred aspect ratio. GTF has no method of determining the 589 * aspect ratio in order to derive the image width from the 590 * image height, so it has to be passed explicitly. Usually 591 * the native screen aspect ratio is used for this. If it 592 * is not filled in correctly, then 16:9 will be assumed. 593 * @fmt - the resulting timings. 594 * 595 * This function will attempt to detect if the given values correspond to a 596 * valid GTF format. If so, then it will return true, and fmt will be filled 597 * in with the found GTF timings. 598 */ 599 bool v4l2_detect_gtf(unsigned frame_height, 600 unsigned hfreq, 601 unsigned vsync, 602 u32 polarities, 603 bool interlaced, 604 struct v4l2_fract aspect, 605 struct v4l2_dv_timings *fmt) 606 { 607 int pix_clk; 608 int v_fp, v_bp, h_fp, hsync; 609 int frame_width, image_height, image_width; 610 bool default_gtf; 611 int h_blank; 612 613 if (vsync != 3) 614 return false; 615 616 if (polarities == V4L2_DV_VSYNC_POS_POL) 617 default_gtf = true; 618 else if (polarities == V4L2_DV_HSYNC_POS_POL) 619 default_gtf = false; 620 else 621 return false; 622 623 if (hfreq == 0) 624 return false; 625 626 /* Vertical */ 627 v_fp = GTF_V_FP; 628 v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync; 629 if (interlaced) 630 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1; 631 else 632 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1; 633 634 if (image_height < 0) 635 return false; 636 637 if (aspect.numerator == 0 || aspect.denominator == 0) { 638 aspect.numerator = 16; 639 aspect.denominator = 9; 640 } 641 image_width = ((image_height * aspect.numerator) / aspect.denominator); 642 image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1); 643 644 /* Horizontal */ 645 if (default_gtf) { 646 u64 num; 647 u32 den; 648 649 num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) - 650 ((u64)image_width * GTF_D_M_PRIME * 1000)); 651 den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) * 652 (2 * GTF_CELL_GRAN); 653 h_blank = div_u64((num + (den >> 1)), den); 654 h_blank *= (2 * GTF_CELL_GRAN); 655 } else { 656 u64 num; 657 u32 den; 658 659 num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) - 660 ((u64)image_width * GTF_S_M_PRIME * 1000)); 661 den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) * 662 (2 * GTF_CELL_GRAN); 663 h_blank = div_u64((num + (den >> 1)), den); 664 h_blank *= (2 * GTF_CELL_GRAN); 665 } 666 667 frame_width = image_width + h_blank; 668 669 pix_clk = (image_width + h_blank) * hfreq; 670 pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN; 671 672 hsync = (frame_width * 8 + 50) / 100; 673 hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN; 674 675 h_fp = h_blank / 2 - hsync; 676 677 fmt->type = V4L2_DV_BT_656_1120; 678 fmt->bt.polarities = polarities; 679 fmt->bt.width = image_width; 680 fmt->bt.height = image_height; 681 fmt->bt.hfrontporch = h_fp; 682 fmt->bt.vfrontporch = v_fp; 683 fmt->bt.hsync = hsync; 684 fmt->bt.vsync = vsync; 685 fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync; 686 687 if (!interlaced) { 688 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync; 689 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE; 690 } else { 691 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp - 692 2 * vsync) / 2; 693 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp - 694 2 * vsync - fmt->bt.vbackporch; 695 fmt->bt.il_vfrontporch = v_fp; 696 fmt->bt.il_vsync = vsync; 697 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE; 698 fmt->bt.interlaced = V4L2_DV_INTERLACED; 699 } 700 701 fmt->bt.pixelclock = pix_clk; 702 fmt->bt.standards = V4L2_DV_BT_STD_GTF; 703 704 if (!default_gtf) 705 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING; 706 707 return true; 708 } 709 EXPORT_SYMBOL_GPL(v4l2_detect_gtf); 710 711 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes 712 * 0x15 and 0x16 from the EDID. 713 * @hor_landscape - byte 0x15 from the EDID. 714 * @vert_portrait - byte 0x16 from the EDID. 715 * 716 * Determines the aspect ratio from the EDID. 717 * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2: 718 * "Horizontal and Vertical Screen Size or Aspect Ratio" 719 */ 720 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait) 721 { 722 struct v4l2_fract aspect = { 16, 9 }; 723 u8 ratio; 724 725 /* Nothing filled in, fallback to 16:9 */ 726 if (!hor_landscape && !vert_portrait) 727 return aspect; 728 /* Both filled in, so they are interpreted as the screen size in cm */ 729 if (hor_landscape && vert_portrait) { 730 aspect.numerator = hor_landscape; 731 aspect.denominator = vert_portrait; 732 return aspect; 733 } 734 /* Only one is filled in, so interpret them as a ratio: 735 (val + 99) / 100 */ 736 ratio = hor_landscape | vert_portrait; 737 /* Change some rounded values into the exact aspect ratio */ 738 if (ratio == 79) { 739 aspect.numerator = 16; 740 aspect.denominator = 9; 741 } else if (ratio == 34) { 742 aspect.numerator = 4; 743 aspect.denominator = 3; 744 } else if (ratio == 68) { 745 aspect.numerator = 15; 746 aspect.denominator = 9; 747 } else { 748 aspect.numerator = hor_landscape + 99; 749 aspect.denominator = 100; 750 } 751 if (hor_landscape) 752 return aspect; 753 /* The aspect ratio is for portrait, so swap numerator and denominator */ 754 swap(aspect.denominator, aspect.numerator); 755 return aspect; 756 } 757 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio); 758