linux/drivers/media/v4l2-core/v4l2-dv-timings.c
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   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
  31MODULE_AUTHOR("Hans Verkuil");
  32MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
  33MODULE_LICENSE("GPL");
  34
  35const 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};
 149EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
 150
 151bool 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}
 177EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
 178
 179int 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}
 197EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
 198
 199bool 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}
 226EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
 227
 228bool 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}
 244EXPORT_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 */
 256bool 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}
 284EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
 285
 286void 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}
 365EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
 366
 367struct 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}
 386EXPORT_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 */
 440bool 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}
 610EXPORT_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 */
 658bool 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}
 768EXPORT_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 */
 779struct 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}
 816EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
 817