drivers/media/v4l2-core/v4l2-dv-timings.c

   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/rational.h>
  26 #include <linux/videodev2.h>
  27 #include <linux/v4l2-dv-timings.h>
  28 #include <media/v4l2-dv-timings.h>
  29 #include <linux/math64.h>
  30
  31 MODULE_AUTHOR("Hans Verkuil");
  32 MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
  33 MODULE_LICENSE("GPL");
  34
  35 const struct v4l2_dv_timings v4l2_dv_timings_presets[] = {
  36         V4L2_DV_BT_CEA_640X480P59_94,
  37         V4L2_DV_BT_CEA_720X480I59_94,
  38         V4L2_DV_BT_CEA_720X480P59_94,
  39         V4L2_DV_BT_CEA_720X576I50,
  40         V4L2_DV_BT_CEA_720X576P50,
  41         V4L2_DV_BT_CEA_1280X720P24,
  42         V4L2_DV_BT_CEA_1280X720P25,
  43         V4L2_DV_BT_CEA_1280X720P30,
  44         V4L2_DV_BT_CEA_1280X720P50,
  45         V4L2_DV_BT_CEA_1280X720P60,
  46         V4L2_DV_BT_CEA_1920X1080P24,
  47         V4L2_DV_BT_CEA_1920X1080P25,
  48         V4L2_DV_BT_CEA_1920X1080P30,
  49         V4L2_DV_BT_CEA_1920X1080I50,
  50         V4L2_DV_BT_CEA_1920X1080P50,
  51         V4L2_DV_BT_CEA_1920X1080I60,
  52         V4L2_DV_BT_CEA_1920X1080P60,
  53         V4L2_DV_BT_DMT_640X350P85,
  54         V4L2_DV_BT_DMT_640X400P85,
  55         V4L2_DV_BT_DMT_720X400P85,
  56         V4L2_DV_BT_DMT_640X480P72,
  57         V4L2_DV_BT_DMT_640X480P75,
  58         V4L2_DV_BT_DMT_640X480P85,
  59         V4L2_DV_BT_DMT_800X600P56,
  60         V4L2_DV_BT_DMT_800X600P60,
  61         V4L2_DV_BT_DMT_800X600P72,
  62         V4L2_DV_BT_DMT_800X600P75,
  63         V4L2_DV_BT_DMT_800X600P85,
  64         V4L2_DV_BT_DMT_800X600P120_RB,
  65         V4L2_DV_BT_DMT_848X480P60,
  66         V4L2_DV_BT_DMT_1024X768I43,
  67         V4L2_DV_BT_DMT_1024X768P60,
  68         V4L2_DV_BT_DMT_1024X768P70,
  69         V4L2_DV_BT_DMT_1024X768P75,
  70         V4L2_DV_BT_DMT_1024X768P85,
  71         V4L2_DV_BT_DMT_1024X768P120_RB,
  72         V4L2_DV_BT_DMT_1152X864P75,
  73         V4L2_DV_BT_DMT_1280X768P60_RB,
  74         V4L2_DV_BT_DMT_1280X768P60,
  75         V4L2_DV_BT_DMT_1280X768P75,
  76         V4L2_DV_BT_DMT_1280X768P85,
  77         V4L2_DV_BT_DMT_1280X768P120_RB,
  78         V4L2_DV_BT_DMT_1280X800P60_RB,
  79         V4L2_DV_BT_DMT_1280X800P60,
  80         V4L2_DV_BT_DMT_1280X800P75,
  81         V4L2_DV_BT_DMT_1280X800P85,
  82         V4L2_DV_BT_DMT_1280X800P120_RB,
  83         V4L2_DV_BT_DMT_1280X960P60,
  84         V4L2_DV_BT_DMT_1280X960P85,
  85         V4L2_DV_BT_DMT_1280X960P120_RB,
  86         V4L2_DV_BT_DMT_1280X1024P60,
  87         V4L2_DV_BT_DMT_1280X1024P75,
  88         V4L2_DV_BT_DMT_1280X1024P85,
  89         V4L2_DV_BT_DMT_1280X1024P120_RB,
  90         V4L2_DV_BT_DMT_1360X768P60,
  91         V4L2_DV_BT_DMT_1360X768P120_RB,
  92         V4L2_DV_BT_DMT_1366X768P60,
  93         V4L2_DV_BT_DMT_1366X768P60_RB,
  94         V4L2_DV_BT_DMT_1400X1050P60_RB,
  95         V4L2_DV_BT_DMT_1400X1050P60,
  96         V4L2_DV_BT_DMT_1400X1050P75,
  97         V4L2_DV_BT_DMT_1400X1050P85,
  98         V4L2_DV_BT_DMT_1400X1050P120_RB,
  99         V4L2_DV_BT_DMT_1440X900P60_RB,
 100         V4L2_DV_BT_DMT_1440X900P60,
 101         V4L2_DV_BT_DMT_1440X900P75,
 102         V4L2_DV_BT_DMT_1440X900P85,
 103         V4L2_DV_BT_DMT_1440X900P120_RB,
 104         V4L2_DV_BT_DMT_1600X900P60_RB,
 105         V4L2_DV_BT_DMT_1600X1200P60,
 106         V4L2_DV_BT_DMT_1600X1200P65,
 107         V4L2_DV_BT_DMT_1600X1200P70,
 108         V4L2_DV_BT_DMT_1600X1200P75,
 109         V4L2_DV_BT_DMT_1600X1200P85,
 110         V4L2_DV_BT_DMT_1600X1200P120_RB,
 111         V4L2_DV_BT_DMT_1680X1050P60_RB,
 112         V4L2_DV_BT_DMT_1680X1050P60,
 113         V4L2_DV_BT_DMT_1680X1050P75,
 114         V4L2_DV_BT_DMT_1680X1050P85,
 115         V4L2_DV_BT_DMT_1680X1050P120_RB,
 116         V4L2_DV_BT_DMT_1792X1344P60,
 117         V4L2_DV_BT_DMT_1792X1344P75,
 118         V4L2_DV_BT_DMT_1792X1344P120_RB,
 119         V4L2_DV_BT_DMT_1856X1392P60,
 120         V4L2_DV_BT_DMT_1856X1392P75,
 121         V4L2_DV_BT_DMT_1856X1392P120_RB,
 122         V4L2_DV_BT_DMT_1920X1200P60_RB,
 123         V4L2_DV_BT_DMT_1920X1200P60,
 124         V4L2_DV_BT_DMT_1920X1200P75,
 125         V4L2_DV_BT_DMT_1920X1200P85,
 126         V4L2_DV_BT_DMT_1920X1200P120_RB,
 127         V4L2_DV_BT_DMT_1920X1440P60,
 128         V4L2_DV_BT_DMT_1920X1440P75,
 129         V4L2_DV_BT_DMT_1920X1440P120_RB,
 130         V4L2_DV_BT_DMT_2048X1152P60_RB,
 131         V4L2_DV_BT_DMT_2560X1600P60_RB,
 132         V4L2_DV_BT_DMT_2560X1600P60,
 133         V4L2_DV_BT_DMT_2560X1600P75,
 134         V4L2_DV_BT_DMT_2560X1600P85,
 135         V4L2_DV_BT_DMT_2560X1600P120_RB,
 136         V4L2_DV_BT_CEA_3840X2160P24,
 137         V4L2_DV_BT_CEA_3840X2160P25,
 138         V4L2_DV_BT_CEA_3840X2160P30,
 139         V4L2_DV_BT_CEA_3840X2160P50,
 140         V4L2_DV_BT_CEA_3840X2160P60,
 141         V4L2_DV_BT_CEA_4096X2160P24,
 142         V4L2_DV_BT_CEA_4096X2160P25,
 143         V4L2_DV_BT_CEA_4096X2160P30,
 144         V4L2_DV_BT_CEA_4096X2160P50,
 145         V4L2_DV_BT_DMT_4096X2160P59_94_RB,
 146         V4L2_DV_BT_CEA_4096X2160P60,
 147         { }
 148 };
 149 EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
 150
 151 bool v4l2_valid_dv_timings(const struct v4l2_dv_timings *t,
 152                            const struct v4l2_dv_timings_cap *dvcap,
 153                            v4l2_check_dv_timings_fnc fnc,
 154                            void *fnc_handle)
 155 {
 156         const struct v4l2_bt_timings *bt = &t->bt;
 157         const struct v4l2_bt_timings_cap *cap = &dvcap->bt;
 158         u32 caps = cap->capabilities;
 159
 160         if (t->type != V4L2_DV_BT_656_1120)
 161                 return false;
 162         if (t->type != dvcap->type ||
 163             bt->height < cap->min_height ||
 164             bt->height > cap->max_height ||
 165             bt->width < cap->min_width ||
 166             bt->width > cap->max_width ||
 167             bt->pixelclock < cap->min_pixelclock ||
 168             bt->pixelclock > cap->max_pixelclock ||
 169             (!(caps & V4L2_DV_BT_CAP_CUSTOM) &&
 170              cap->standards && bt->standards &&
 171              !(bt->standards & cap->standards)) ||
 172             (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
 173             (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
 174                 return false;
 175         return fnc == NULL || fnc(t, fnc_handle);
 176 }
 177 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
 178
 179 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
 180                              const struct v4l2_dv_timings_cap *cap,
 181                              v4l2_check_dv_timings_fnc fnc,
 182                              void *fnc_handle)
 183 {
 184         u32 i, idx;
 185
 186         memset(t->reserved, 0, sizeof(t->reserved));
 187         for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
 188                 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
 189                                           fnc, fnc_handle) &&
 190                     idx++ == t->index) {
 191                         t->timings = v4l2_dv_timings_presets[i];
 192                         return 0;
 193                 }
 194         }
 195         return -EINVAL;
 196 }
 197 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
 198
 199 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
 200                               const struct v4l2_dv_timings_cap *cap,
 201                               unsigned pclock_delta,
 202                               v4l2_check_dv_timings_fnc fnc,
 203                               void *fnc_handle)
 204 {
 205         int i;
 206
 207         if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
 208                 return false;
 209
 210         for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
 211                 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
 212                                           fnc, fnc_handle) &&
 213                     v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
 214                                           pclock_delta, false)) {
 215                         u32 flags = t->bt.flags & V4L2_DV_FL_REDUCED_FPS;
 216
 217                         *t = v4l2_dv_timings_presets[i];
 218                         if (can_reduce_fps(&t->bt))
 219                                 t->bt.flags |= flags;
 220
 221                         return true;
 222                 }
 223         }
 224         return false;
 225 }
 226 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
 227
 228 bool v4l2_find_dv_timings_cea861_vic(struct v4l2_dv_timings *t, u8 vic)
 229 {
 230         unsigned int i;
 231
 232         for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
 233                 const struct v4l2_bt_timings *bt =
 234                         &v4l2_dv_timings_presets[i].bt;
 235
 236                 if ((bt->flags & V4L2_DV_FL_HAS_CEA861_VIC) &&
 237                     bt->cea861_vic == vic) {
 238                         *t = v4l2_dv_timings_presets[i];
 239                         return true;
 240                 }
 241         }
 242         return false;
 243 }
 244 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cea861_vic);
 245
 246 /**
 247  * v4l2_match_dv_timings - check if two timings match
 248  * @t1: compare this v4l2_dv_timings struct...
 249  * @t2: with this struct.
 250  * @pclock_delta: the allowed pixelclock deviation.
 251  * @match_reduced_fps: if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
 252  *      match.
 253  *
 254  * Compare t1 with t2 with a given margin of error for the pixelclock.
 255  */
 256 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
 257                            const struct v4l2_dv_timings *t2,
 258                            unsigned pclock_delta, bool match_reduced_fps)
 259 {
 260         if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
 261                 return false;
 262         if (t1->bt.width == t2->bt.width &&
 263             t1->bt.height == t2->bt.height &&
 264             t1->bt.interlaced == t2->bt.interlaced &&
 265             t1->bt.polarities == t2->bt.polarities &&
 266             t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
 267             t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
 268             t1->bt.hfrontporch == t2->bt.hfrontporch &&
 269             t1->bt.hsync == t2->bt.hsync &&
 270             t1->bt.hbackporch == t2->bt.hbackporch &&
 271             t1->bt.vfrontporch == t2->bt.vfrontporch &&
 272             t1->bt.vsync == t2->bt.vsync &&
 273             t1->bt.vbackporch == t2->bt.vbackporch &&
 274             (!match_reduced_fps ||
 275              (t1->bt.flags & V4L2_DV_FL_REDUCED_FPS) ==
 276                 (t2->bt.flags & V4L2_DV_FL_REDUCED_FPS)) &&
 277             (!t1->bt.interlaced ||
 278                 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
 279                  t1->bt.il_vsync == t2->bt.il_vsync &&
 280                  t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
 281                 return true;
 282         return false;
 283 }
 284 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
 285
 286 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
 287                            const struct v4l2_dv_timings *t, bool detailed)
 288 {
 289         const struct v4l2_bt_timings *bt = &t->bt;
 290         u32 htot, vtot;
 291         u32 fps;
 292
 293         if (t->type != V4L2_DV_BT_656_1120)
 294                 return;
 295
 296         htot = V4L2_DV_BT_FRAME_WIDTH(bt);
 297         vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
 298         if (bt->interlaced)
 299                 vtot /= 2;
 300
 301         fps = (htot * vtot) > 0 ? div_u64((100 * (u64)bt->pixelclock),
 302                                   (htot * vtot)) : 0;
 303
 304         if (prefix == NULL)
 305                 prefix = "";
 306
 307         pr_info("%s: %s%ux%u%s%u.%u (%ux%u)\n", dev_prefix, prefix,
 308                 bt->width, bt->height, bt->interlaced ? "i" : "p",
 309                 fps / 100, fps % 100, htot, vtot);
 310
 311         if (!detailed)
 312                 return;
 313
 314         pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
 315                         dev_prefix, bt->hfrontporch,
 316                         (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
 317                         bt->hsync, bt->hbackporch);
 318         pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
 319                         dev_prefix, bt->vfrontporch,
 320                         (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
 321                         bt->vsync, bt->vbackporch);
 322         if (bt->interlaced)
 323                 pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n",
 324                         dev_prefix, bt->il_vfrontporch,
 325                         (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
 326                         bt->il_vsync, bt->il_vbackporch);
 327         pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
 328         pr_info("%s: flags (0x%x):%s%s%s%s%s%s%s%s%s%s\n",
 329                         dev_prefix, bt->flags,
 330                         (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
 331                         " REDUCED_BLANKING" : "",
 332                         ((bt->flags & V4L2_DV_FL_REDUCED_BLANKING) &&
 333                          bt->vsync == 8) ? " (V2)" : "",
 334                         (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
 335                         " CAN_REDUCE_FPS" : "",
 336                         (bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
 337                         " REDUCED_FPS" : "",
 338                         (bt->flags & V4L2_DV_FL_HALF_LINE) ?
 339                         " HALF_LINE" : "",
 340                         (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ?
 341                         " CE_VIDEO" : "",
 342                         (bt->flags & V4L2_DV_FL_FIRST_FIELD_EXTRA_LINE) ?
 343                         " FIRST_FIELD_EXTRA_LINE" : "",
 344                         (bt->flags & V4L2_DV_FL_HAS_PICTURE_ASPECT) ?
 345                         " HAS_PICTURE_ASPECT" : "",
 346                         (bt->flags & V4L2_DV_FL_HAS_CEA861_VIC) ?
 347                         " HAS_CEA861_VIC" : "",
 348                         (bt->flags & V4L2_DV_FL_HAS_HDMI_VIC) ?
 349                         " HAS_HDMI_VIC" : "");
 350         pr_info("%s: standards (0x%x):%s%s%s%s%s\n", dev_prefix, bt->standards,
 351                         (bt->standards & V4L2_DV_BT_STD_CEA861) ?  " CEA" : "",
 352                         (bt->standards & V4L2_DV_BT_STD_DMT) ?  " DMT" : "",
 353                         (bt->standards & V4L2_DV_BT_STD_CVT) ?  " CVT" : "",
 354                         (bt->standards & V4L2_DV_BT_STD_GTF) ?  " GTF" : "",
 355                         (bt->standards & V4L2_DV_BT_STD_SDI) ?  " SDI" : "");
 356         if (bt->flags & V4L2_DV_FL_HAS_PICTURE_ASPECT)
 357                 pr_info("%s: picture aspect (hor:vert): %u:%u\n", dev_prefix,
 358                         bt->picture_aspect.numerator,
 359                         bt->picture_aspect.denominator);
 360         if (bt->flags & V4L2_DV_FL_HAS_CEA861_VIC)
 361                 pr_info("%s: CEA-861 VIC: %u\n", dev_prefix, bt->cea861_vic);
 362         if (bt->flags & V4L2_DV_FL_HAS_HDMI_VIC)
 363                 pr_info("%s: HDMI VIC: %u\n", dev_prefix, bt->hdmi_vic);
 364 }
 365 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
 366
 367 struct v4l2_fract v4l2_dv_timings_aspect_ratio(const struct v4l2_dv_timings *t)
 368 {
 369         struct v4l2_fract ratio = { 1, 1 };
 370         unsigned long n, d;
 371
 372         if (t->type != V4L2_DV_BT_656_1120)
 373                 return ratio;
 374         if (!(t->bt.flags & V4L2_DV_FL_HAS_PICTURE_ASPECT))
 375                 return ratio;
 376
 377         ratio.numerator = t->bt.width * t->bt.picture_aspect.denominator;
 378         ratio.denominator = t->bt.height * t->bt.picture_aspect.numerator;
 379
 380         rational_best_approximation(ratio.numerator, ratio.denominator,
 381                                     ratio.numerator, ratio.denominator, &n, &d);
 382         ratio.numerator = n;
 383         ratio.denominator = d;
 384         return ratio;
 385 }
 386 EXPORT_SYMBOL_GPL(v4l2_dv_timings_aspect_ratio);
 387
 388 /*
 389  * CVT defines
 390  * Based on Coordinated Video Timings Standard
 391  * version 1.1 September 10, 2003
 392  */
 393
 394 #define CVT_PXL_CLK_GRAN        250000  /* pixel clock granularity */
 395 #define CVT_PXL_CLK_GRAN_RB_V2 1000     /* granularity for reduced blanking v2*/
 396
 397 /* Normal blanking */
 398 #define CVT_MIN_V_BPORCH        7       /* lines */
 399 #define CVT_MIN_V_PORCH_RND     3       /* lines */
 400 #define CVT_MIN_VSYNC_BP        550     /* min time of vsync + back porch (us) */
 401 #define CVT_HSYNC_PERCENT       8       /* nominal hsync as percentage of line */
 402
 403 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
 404 #define CVT_CELL_GRAN           8       /* character cell granularity */
 405 #define CVT_M                   600     /* blanking formula gradient */
 406 #define CVT_C                   40      /* blanking formula offset */
 407 #define CVT_K                   128     /* blanking formula scaling factor */
 408 #define CVT_J                   20      /* blanking formula scaling factor */
 409 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
 410 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
 411
 412 /* Reduced Blanking */
 413 #define CVT_RB_MIN_V_BPORCH    7       /* lines  */
 414 #define CVT_RB_V_FPORCH        3       /* lines  */
 415 #define CVT_RB_MIN_V_BLANK   460       /* us     */
 416 #define CVT_RB_H_SYNC         32       /* pixels */
 417 #define CVT_RB_H_BLANK       160       /* pixels */
 418 /* Reduce blanking Version 2 */
 419 #define CVT_RB_V2_H_BLANK     80       /* pixels */
 420 #define CVT_RB_MIN_V_FPORCH    3       /* lines  */
 421 #define CVT_RB_V2_MIN_V_FPORCH 1       /* lines  */
 422 #define CVT_RB_V_BPORCH        6       /* lines  */
 423
 424 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
 425  * @frame_height - the total height of the frame (including blanking) in lines.
 426  * @hfreq - the horizontal frequency in Hz.
 427  * @vsync - the height of the vertical sync in lines.
 428  * @active_width - active width of image (does not include blanking). This
 429  * information is needed only in case of version 2 of reduced blanking.
 430  * In other cases, this parameter does not have any effect on timings.
 431  * @polarities - the horizontal and vertical polarities (same as struct
 432  *              v4l2_bt_timings polarities).
 433  * @interlaced - if this flag is true, it indicates interlaced format
 434  * @fmt - the resulting timings.
 435  *
 436  * This function will attempt to detect if the given values correspond to a
 437  * valid CVT format. If so, then it will return true, and fmt will be filled
 438  * in with the found CVT timings.
 439  */
 440 bool v4l2_detect_cvt(unsigned frame_height,
 441                      unsigned hfreq,
 442                      unsigned vsync,
 443                      unsigned active_width,
 444                      u32 polarities,
 445                      bool interlaced,
 446                      struct v4l2_dv_timings *fmt)
 447 {
 448         int  v_fp, v_bp, h_fp, h_bp, hsync;
 449         int  frame_width, image_height, image_width;
 450         bool reduced_blanking;
 451         bool rb_v2 = false;
 452         unsigned pix_clk;
 453
 454         if (vsync < 4 || vsync > 8)
 455                 return false;
 456
 457         if (polarities == V4L2_DV_VSYNC_POS_POL)
 458                 reduced_blanking = false;
 459         else if (polarities == V4L2_DV_HSYNC_POS_POL)
 460                 reduced_blanking = true;
 461         else
 462                 return false;
 463
 464         if (reduced_blanking && vsync == 8)
 465                 rb_v2 = true;
 466
 467         if (rb_v2 && active_width == 0)
 468                 return false;
 469
 470         if (!rb_v2 && vsync > 7)
 471                 return false;
 472
 473         if (hfreq == 0)
 474                 return false;
 475
 476         /* Vertical */
 477         if (reduced_blanking) {
 478                 if (rb_v2) {
 479                         v_bp = CVT_RB_V_BPORCH;
 480                         v_fp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
 481                         v_fp -= vsync + v_bp;
 482
 483                         if (v_fp < CVT_RB_V2_MIN_V_FPORCH)
 484                                 v_fp = CVT_RB_V2_MIN_V_FPORCH;
 485                 } else {
 486                         v_fp = CVT_RB_V_FPORCH;
 487                         v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
 488                         v_bp -= vsync + v_fp;
 489
 490                         if (v_bp < CVT_RB_MIN_V_BPORCH)
 491                                 v_bp = CVT_RB_MIN_V_BPORCH;
 492                 }
 493         } else {
 494                 v_fp = CVT_MIN_V_PORCH_RND;
 495                 v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync;
 496
 497                 if (v_bp < CVT_MIN_V_BPORCH)
 498                         v_bp = CVT_MIN_V_BPORCH;
 499         }
 500
 501         if (interlaced)
 502                 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
 503         else
 504                 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 505
 506         if (image_height < 0)
 507                 return false;
 508
 509         /* Aspect ratio based on vsync */
 510         switch (vsync) {
 511         case 4:
 512                 image_width = (image_height * 4) / 3;
 513                 break;
 514         case 5:
 515                 image_width = (image_height * 16) / 9;
 516                 break;
 517         case 6:
 518                 image_width = (image_height * 16) / 10;
 519                 break;
 520         case 7:
 521                 /* special case */
 522                 if (image_height == 1024)
 523                         image_width = (image_height * 5) / 4;
 524                 else if (image_height == 768)
 525                         image_width = (image_height * 15) / 9;
 526                 else
 527                         return false;
 528                 break;
 529         case 8:
 530                 image_width = active_width;
 531                 break;
 532         default:
 533                 return false;
 534         }
 535
 536         if (!rb_v2)
 537                 image_width = image_width & ~7;
 538
 539         /* Horizontal */
 540         if (reduced_blanking) {
 541                 int h_blank;
 542                 int clk_gran;
 543
 544                 h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK;
 545                 clk_gran = rb_v2 ? CVT_PXL_CLK_GRAN_RB_V2 : CVT_PXL_CLK_GRAN;
 546
 547                 pix_clk = (image_width + h_blank) * hfreq;
 548                 pix_clk = (pix_clk / clk_gran) * clk_gran;
 549
 550                 h_bp  = h_blank / 2;
 551                 hsync = CVT_RB_H_SYNC;
 552                 h_fp  = h_blank - h_bp - hsync;
 553
 554                 frame_width = image_width + h_blank;
 555         } else {
 556                 unsigned ideal_duty_cycle_per_myriad =
 557                         100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
 558                 int h_blank;
 559
 560                 if (ideal_duty_cycle_per_myriad < 2000)
 561                         ideal_duty_cycle_per_myriad = 2000;
 562
 563                 h_blank = image_width * ideal_duty_cycle_per_myriad /
 564                                         (10000 - ideal_duty_cycle_per_myriad);
 565                 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
 566
 567                 pix_clk = (image_width + h_blank) * hfreq;
 568                 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
 569
 570                 h_bp = h_blank / 2;
 571                 frame_width = image_width + h_blank;
 572
 573                 hsync = frame_width * CVT_HSYNC_PERCENT / 100;
 574                 hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN;
 575                 h_fp = h_blank - hsync - h_bp;
 576         }
 577
 578         fmt->type = V4L2_DV_BT_656_1120;
 579         fmt->bt.polarities = polarities;
 580         fmt->bt.width = image_width;
 581         fmt->bt.height = image_height;
 582         fmt->bt.hfrontporch = h_fp;
 583         fmt->bt.vfrontporch = v_fp;
 584         fmt->bt.hsync = hsync;
 585         fmt->bt.vsync = vsync;
 586         fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
 587
 588         if (!interlaced) {
 589                 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
 590                 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
 591         } else {
 592                 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
 593                                       2 * vsync) / 2;
 594                 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
 595                                         2 * vsync - fmt->bt.vbackporch;
 596                 fmt->bt.il_vfrontporch = v_fp;
 597                 fmt->bt.il_vsync = vsync;
 598                 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
 599                 fmt->bt.interlaced = V4L2_DV_INTERLACED;
 600         }
 601
 602         fmt->bt.pixelclock = pix_clk;
 603         fmt->bt.standards = V4L2_DV_BT_STD_CVT;
 604
 605         if (reduced_blanking)
 606                 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
 607
 608         return true;
 609 }
 610 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
 611
 612 /*
 613  * GTF defines
 614  * Based on Generalized Timing Formula Standard
 615  * Version 1.1 September 2, 1999
 616  */
 617
 618 #define GTF_PXL_CLK_GRAN        250000  /* pixel clock granularity */
 619
 620 #define GTF_MIN_VSYNC_BP        550     /* min time of vsync + back porch (us) */
 621 #define GTF_V_FP                1       /* vertical front porch (lines) */
 622 #define GTF_CELL_GRAN           8       /* character cell granularity */
 623
 624 /* Default */
 625 #define GTF_D_M                 600     /* blanking formula gradient */
 626 #define GTF_D_C                 40      /* blanking formula offset */
 627 #define GTF_D_K                 128     /* blanking formula scaling factor */
 628 #define GTF_D_J                 20      /* blanking formula scaling factor */
 629 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
 630 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
 631
 632 /* Secondary */
 633 #define GTF_S_M                 3600    /* blanking formula gradient */
 634 #define GTF_S_C                 40      /* blanking formula offset */
 635 #define GTF_S_K                 128     /* blanking formula scaling factor */
 636 #define GTF_S_J                 35      /* blanking formula scaling factor */
 637 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
 638 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
 639
 640 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
 641  * @frame_height - the total height of the frame (including blanking) in lines.
 642  * @hfreq - the horizontal frequency in Hz.
 643  * @vsync - the height of the vertical sync in lines.
 644  * @polarities - the horizontal and vertical polarities (same as struct
 645  *              v4l2_bt_timings polarities).
 646  * @interlaced - if this flag is true, it indicates interlaced format
 647  * @aspect - preferred aspect ratio. GTF has no method of determining the
 648  *              aspect ratio in order to derive the image width from the
 649  *              image height, so it has to be passed explicitly. Usually
 650  *              the native screen aspect ratio is used for this. If it
 651  *              is not filled in correctly, then 16:9 will be assumed.
 652  * @fmt - the resulting timings.
 653  *
 654  * This function will attempt to detect if the given values correspond to a
 655  * valid GTF format. If so, then it will return true, and fmt will be filled
 656  * in with the found GTF timings.
 657  */
 658 bool v4l2_detect_gtf(unsigned frame_height,
 659                 unsigned hfreq,
 660                 unsigned vsync,
 661                 u32 polarities,
 662                 bool interlaced,
 663                 struct v4l2_fract aspect,
 664                 struct v4l2_dv_timings *fmt)
 665 {
 666         int pix_clk;
 667         int  v_fp, v_bp, h_fp, hsync;
 668         int frame_width, image_height, image_width;
 669         bool default_gtf;
 670         int h_blank;
 671
 672         if (vsync != 3)
 673                 return false;
 674
 675         if (polarities == V4L2_DV_VSYNC_POS_POL)
 676                 default_gtf = true;
 677         else if (polarities == V4L2_DV_HSYNC_POS_POL)
 678                 default_gtf = false;
 679         else
 680                 return false;
 681
 682         if (hfreq == 0)
 683                 return false;
 684
 685         /* Vertical */
 686         v_fp = GTF_V_FP;
 687         v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync;
 688         if (interlaced)
 689                 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
 690         else
 691                 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 692
 693         if (image_height < 0)
 694                 return false;
 695
 696         if (aspect.numerator == 0 || aspect.denominator == 0) {
 697                 aspect.numerator = 16;
 698                 aspect.denominator = 9;
 699         }
 700         image_width = ((image_height * aspect.numerator) / aspect.denominator);
 701         image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
 702
 703         /* Horizontal */
 704         if (default_gtf) {
 705                 u64 num;
 706                 u32 den;
 707
 708                 num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) -
 709                       ((u64)image_width * GTF_D_M_PRIME * 1000));
 710                 den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) *
 711                       (2 * GTF_CELL_GRAN);
 712                 h_blank = div_u64((num + (den >> 1)), den);
 713                 h_blank *= (2 * GTF_CELL_GRAN);
 714         } else {
 715                 u64 num;
 716                 u32 den;
 717
 718                 num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) -
 719                       ((u64)image_width * GTF_S_M_PRIME * 1000));
 720                 den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) *
 721                       (2 * GTF_CELL_GRAN);
 722                 h_blank = div_u64((num + (den >> 1)), den);
 723                 h_blank *= (2 * GTF_CELL_GRAN);
 724         }
 725
 726         frame_width = image_width + h_blank;
 727
 728         pix_clk = (image_width + h_blank) * hfreq;
 729         pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
 730
 731         hsync = (frame_width * 8 + 50) / 100;
 732         hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN;
 733
 734         h_fp = h_blank / 2 - hsync;
 735
 736         fmt->type = V4L2_DV_BT_656_1120;
 737         fmt->bt.polarities = polarities;
 738         fmt->bt.width = image_width;
 739         fmt->bt.height = image_height;
 740         fmt->bt.hfrontporch = h_fp;
 741         fmt->bt.vfrontporch = v_fp;
 742         fmt->bt.hsync = hsync;
 743         fmt->bt.vsync = vsync;
 744         fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
 745
 746         if (!interlaced) {
 747                 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
 748                 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
 749         } else {
 750                 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
 751                                       2 * vsync) / 2;
 752                 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
 753                                         2 * vsync - fmt->bt.vbackporch;
 754                 fmt->bt.il_vfrontporch = v_fp;
 755                 fmt->bt.il_vsync = vsync;
 756                 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
 757                 fmt->bt.interlaced = V4L2_DV_INTERLACED;
 758         }
 759
 760         fmt->bt.pixelclock = pix_clk;
 761         fmt->bt.standards = V4L2_DV_BT_STD_GTF;
 762
 763         if (!default_gtf)
 764                 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
 765
 766         return true;
 767 }
 768 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
 769
 770 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
 771  *      0x15 and 0x16 from the EDID.
 772  * @hor_landscape - byte 0x15 from the EDID.
 773  * @vert_portrait - byte 0x16 from the EDID.
 774  *
 775  * Determines the aspect ratio from the EDID.
 776  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
 777  * "Horizontal and Vertical Screen Size or Aspect Ratio"
 778  */
 779 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
 780 {
 781         struct v4l2_fract aspect = { 16, 9 };
 782         u8 ratio;
 783
 784         /* Nothing filled in, fallback to 16:9 */
 785         if (!hor_landscape && !vert_portrait)
 786                 return aspect;
 787         /* Both filled in, so they are interpreted as the screen size in cm */
 788         if (hor_landscape && vert_portrait) {
 789                 aspect.numerator = hor_landscape;
 790                 aspect.denominator = vert_portrait;
 791                 return aspect;
 792         }
 793         /* Only one is filled in, so interpret them as a ratio:
 794            (val + 99) / 100 */
 795         ratio = hor_landscape | vert_portrait;
 796         /* Change some rounded values into the exact aspect ratio */
 797         if (ratio == 79) {
 798                 aspect.numerator = 16;
 799                 aspect.denominator = 9;
 800         } else if (ratio == 34) {
 801                 aspect.numerator = 4;
 802                 aspect.denominator = 3;
 803         } else if (ratio == 68) {
 804                 aspect.numerator = 15;
 805                 aspect.denominator = 9;
 806         } else {
 807                 aspect.numerator = hor_landscape + 99;
 808                 aspect.denominator = 100;
 809         }
 810         if (hor_landscape)
 811                 return aspect;
 812         /* The aspect ratio is for portrait, so swap numerator and denominator */
 813         swap(aspect.denominator, aspect.numerator);
 814         return aspect;
 815 }
 816 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);