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/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         const u32 max_vert = 10240;
 159         u32 max_hor = 3 * bt->width;
 160
 161         if (t->type != V4L2_DV_BT_656_1120)
 162                 return false;
 163         if (t->type != dvcap->type ||
 164             bt->height < cap->min_height ||
 165             bt->height > cap->max_height ||
 166             bt->width < cap->min_width ||
 167             bt->width > cap->max_width ||
 168             bt->pixelclock < cap->min_pixelclock ||
 169             bt->pixelclock > cap->max_pixelclock ||
 170             (!(caps & V4L2_DV_BT_CAP_CUSTOM) &&
 171              cap->standards && bt->standards &&
 172              !(bt->standards & cap->standards)) ||
 173             (bt->interlaced && !(caps & V4L2_DV_BT_CAP_INTERLACED)) ||
 174             (!bt->interlaced && !(caps & V4L2_DV_BT_CAP_PROGRESSIVE)))
 175                 return false;
 176
 177         /* sanity checks for the blanking timings */
 178         if (!bt->interlaced &&
 179             (bt->il_vbackporch || bt->il_vsync || bt->il_vfrontporch))
 180                 return false;
 181         /*
 182          * Some video receivers cannot properly separate the frontporch,
 183          * backporch and sync values, and instead they only have the total
 184          * blanking. That can be assigned to any of these three fields.
 185          * So just check that none of these are way out of range.
 186          */
 187         if (bt->hfrontporch > max_hor ||
 188             bt->hsync > max_hor || bt->hbackporch > max_hor)
 189                 return false;
 190         if (bt->vfrontporch > max_vert ||
 191             bt->vsync > max_vert || bt->vbackporch > max_vert)
 192                 return false;
 193         if (bt->interlaced && (bt->il_vfrontporch > max_vert ||
 194             bt->il_vsync > max_vert || bt->il_vbackporch > max_vert))
 195                 return false;
 196         return fnc == NULL || fnc(t, fnc_handle);
 197 }
 198 EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
 199
 200 int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
 201                              const struct v4l2_dv_timings_cap *cap,
 202                              v4l2_check_dv_timings_fnc fnc,
 203                              void *fnc_handle)
 204 {
 205         u32 i, idx;
 206
 207         memset(t->reserved, 0, sizeof(t->reserved));
 208         for (i = idx = 0; 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                     idx++ == t->index) {
 212                         t->timings = v4l2_dv_timings_presets[i];
 213                         return 0;
 214                 }
 215         }
 216         return -EINVAL;
 217 }
 218 EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
 219
 220 bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
 221                               const struct v4l2_dv_timings_cap *cap,
 222                               unsigned pclock_delta,
 223                               v4l2_check_dv_timings_fnc fnc,
 224                               void *fnc_handle)
 225 {
 226         int i;
 227
 228         if (!v4l2_valid_dv_timings(t, cap, fnc, fnc_handle))
 229                 return false;
 230
 231         for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
 232                 if (v4l2_valid_dv_timings(v4l2_dv_timings_presets + i, cap,
 233                                           fnc, fnc_handle) &&
 234                     v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i,
 235                                           pclock_delta, false)) {
 236                         u32 flags = t->bt.flags & V4L2_DV_FL_REDUCED_FPS;
 237
 238                         *t = v4l2_dv_timings_presets[i];
 239                         if (can_reduce_fps(&t->bt))
 240                                 t->bt.flags |= flags;
 241
 242                         return true;
 243                 }
 244         }
 245         return false;
 246 }
 247 EXPORT_SYMBOL_GPL(v4l2_find_dv_timings_cap);
 248
 249 /**
 250  * v4l2_match_dv_timings - check if two timings match
 251  * @t1 - compare this v4l2_dv_timings struct...
 252  * @t2 - with this struct.
 253  * @pclock_delta - the allowed pixelclock deviation.
 254  * @match_reduced_fps - if true, then fail if V4L2_DV_FL_REDUCED_FPS does not
 255  * match.
 256  *
 257  * Compare t1 with t2 with a given margin of error for the pixelclock.
 258  */
 259 bool v4l2_match_dv_timings(const struct v4l2_dv_timings *t1,
 260                            const struct v4l2_dv_timings *t2,
 261                            unsigned pclock_delta, bool match_reduced_fps)
 262 {
 263         if (t1->type != t2->type || t1->type != V4L2_DV_BT_656_1120)
 264                 return false;
 265         if (t1->bt.width == t2->bt.width &&
 266             t1->bt.height == t2->bt.height &&
 267             t1->bt.interlaced == t2->bt.interlaced &&
 268             t1->bt.polarities == t2->bt.polarities &&
 269             t1->bt.pixelclock >= t2->bt.pixelclock - pclock_delta &&
 270             t1->bt.pixelclock <= t2->bt.pixelclock + pclock_delta &&
 271             t1->bt.hfrontporch == t2->bt.hfrontporch &&
 272             t1->bt.hsync == t2->bt.hsync &&
 273             t1->bt.hbackporch == t2->bt.hbackporch &&
 274             t1->bt.vfrontporch == t2->bt.vfrontporch &&
 275             t1->bt.vsync == t2->bt.vsync &&
 276             t1->bt.vbackporch == t2->bt.vbackporch &&
 277             (!match_reduced_fps ||
 278              (t1->bt.flags & V4L2_DV_FL_REDUCED_FPS) ==
 279                 (t2->bt.flags & V4L2_DV_FL_REDUCED_FPS)) &&
 280             (!t1->bt.interlaced ||
 281                 (t1->bt.il_vfrontporch == t2->bt.il_vfrontporch &&
 282                  t1->bt.il_vsync == t2->bt.il_vsync &&
 283                  t1->bt.il_vbackporch == t2->bt.il_vbackporch)))
 284                 return true;
 285         return false;
 286 }
 287 EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
 288
 289 void v4l2_print_dv_timings(const char *dev_prefix, const char *prefix,
 290                            const struct v4l2_dv_timings *t, bool detailed)
 291 {
 292         const struct v4l2_bt_timings *bt = &t->bt;
 293         u32 htot, vtot;
 294         u32 fps;
 295
 296         if (t->type != V4L2_DV_BT_656_1120)
 297                 return;
 298
 299         htot = V4L2_DV_BT_FRAME_WIDTH(bt);
 300         vtot = V4L2_DV_BT_FRAME_HEIGHT(bt);
 301         if (bt->interlaced)
 302                 vtot /= 2;
 303
 304         fps = (htot * vtot) > 0 ? div_u64((100 * (u64)bt->pixelclock),
 305                                   (htot * vtot)) : 0;
 306
 307         if (prefix == NULL)
 308                 prefix = "";
 309
 310         pr_info("%s: %s%ux%u%s%u.%u (%ux%u)\n", dev_prefix, prefix,
 311                 bt->width, bt->height, bt->interlaced ? "i" : "p",
 312                 fps / 100, fps % 100, htot, vtot);
 313
 314         if (!detailed)
 315                 return;
 316
 317         pr_info("%s: horizontal: fp = %u, %ssync = %u, bp = %u\n",
 318                         dev_prefix, bt->hfrontporch,
 319                         (bt->polarities & V4L2_DV_HSYNC_POS_POL) ? "+" : "-",
 320                         bt->hsync, bt->hbackporch);
 321         pr_info("%s: vertical: fp = %u, %ssync = %u, bp = %u\n",
 322                         dev_prefix, bt->vfrontporch,
 323                         (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
 324                         bt->vsync, bt->vbackporch);
 325         if (bt->interlaced)
 326                 pr_info("%s: vertical bottom field: fp = %u, %ssync = %u, bp = %u\n",
 327                         dev_prefix, bt->il_vfrontporch,
 328                         (bt->polarities & V4L2_DV_VSYNC_POS_POL) ? "+" : "-",
 329                         bt->il_vsync, bt->il_vbackporch);
 330         pr_info("%s: pixelclock: %llu\n", dev_prefix, bt->pixelclock);
 331         pr_info("%s: flags (0x%x):%s%s%s%s%s%s%s\n", dev_prefix, bt->flags,
 332                         (bt->flags & V4L2_DV_FL_REDUCED_BLANKING) ?
 333                         " REDUCED_BLANKING" : "",
 334                         ((bt->flags & V4L2_DV_FL_REDUCED_BLANKING) &&
 335                          bt->vsync == 8) ? " (V2)" : "",
 336                         (bt->flags & V4L2_DV_FL_CAN_REDUCE_FPS) ?
 337                         " CAN_REDUCE_FPS" : "",
 338                         (bt->flags & V4L2_DV_FL_REDUCED_FPS) ?
 339                         " REDUCED_FPS" : "",
 340                         (bt->flags & V4L2_DV_FL_HALF_LINE) ?
 341                         " HALF_LINE" : "",
 342                         (bt->flags & V4L2_DV_FL_IS_CE_VIDEO) ?
 343                         " CE_VIDEO" : "",
 344                         (bt->flags & V4L2_DV_FL_FIRST_FIELD_EXTRA_LINE) ?
 345                         " FIRST_FIELD_EXTRA_LINE" : "");
 346         pr_info("%s: standards (0x%x):%s%s%s%s%s\n", dev_prefix, bt->standards,
 347                         (bt->standards & V4L2_DV_BT_STD_CEA861) ?  " CEA" : "",
 348                         (bt->standards & V4L2_DV_BT_STD_DMT) ?  " DMT" : "",
 349                         (bt->standards & V4L2_DV_BT_STD_CVT) ?  " CVT" : "",
 350                         (bt->standards & V4L2_DV_BT_STD_GTF) ?  " GTF" : "",
 351                         (bt->standards & V4L2_DV_BT_STD_SDI) ?  " SDI" : "");
 352 }
 353 EXPORT_SYMBOL_GPL(v4l2_print_dv_timings);
 354
 355 /*
 356  * CVT defines
 357  * Based on Coordinated Video Timings Standard
 358  * version 1.1 September 10, 2003
 359  */
 360
 361 #define CVT_PXL_CLK_GRAN        250000  /* pixel clock granularity */
 362 #define CVT_PXL_CLK_GRAN_RB_V2 1000     /* granularity for reduced blanking v2*/
 363
 364 /* Normal blanking */
 365 #define CVT_MIN_V_BPORCH        7       /* lines */
 366 #define CVT_MIN_V_PORCH_RND     3       /* lines */
 367 #define CVT_MIN_VSYNC_BP        550     /* min time of vsync + back porch (us) */
 368 #define CVT_HSYNC_PERCENT       8       /* nominal hsync as percentage of line */
 369
 370 /* Normal blanking for CVT uses GTF to calculate horizontal blanking */
 371 #define CVT_CELL_GRAN           8       /* character cell granularity */
 372 #define CVT_M                   600     /* blanking formula gradient */
 373 #define CVT_C                   40      /* blanking formula offset */
 374 #define CVT_K                   128     /* blanking formula scaling factor */
 375 #define CVT_J                   20      /* blanking formula scaling factor */
 376 #define CVT_C_PRIME (((CVT_C - CVT_J) * CVT_K / 256) + CVT_J)
 377 #define CVT_M_PRIME (CVT_K * CVT_M / 256)
 378
 379 /* Reduced Blanking */
 380 #define CVT_RB_MIN_V_BPORCH    7       /* lines  */
 381 #define CVT_RB_V_FPORCH        3       /* lines  */
 382 #define CVT_RB_MIN_V_BLANK   460       /* us     */
 383 #define CVT_RB_H_SYNC         32       /* pixels */
 384 #define CVT_RB_H_BLANK       160       /* pixels */
 385 /* Reduce blanking Version 2 */
 386 #define CVT_RB_V2_H_BLANK     80       /* pixels */
 387 #define CVT_RB_MIN_V_FPORCH    3       /* lines  */
 388 #define CVT_RB_V2_MIN_V_FPORCH 1       /* lines  */
 389 #define CVT_RB_V_BPORCH        6       /* lines  */
 390
 391 /** v4l2_detect_cvt - detect if the given timings follow the CVT standard
 392  * @frame_height - the total height of the frame (including blanking) in lines.
 393  * @hfreq - the horizontal frequency in Hz.
 394  * @vsync - the height of the vertical sync in lines.
 395  * @active_width - active width of image (does not include blanking). This
 396  * information is needed only in case of version 2 of reduced blanking.
 397  * In other cases, this parameter does not have any effect on timings.
 398  * @polarities - the horizontal and vertical polarities (same as struct
 399  *              v4l2_bt_timings polarities).
 400  * @interlaced - if this flag is true, it indicates interlaced format
 401  * @fmt - the resulting timings.
 402  *
 403  * This function will attempt to detect if the given values correspond to a
 404  * valid CVT format. If so, then it will return true, and fmt will be filled
 405  * in with the found CVT timings.
 406  */
 407 bool v4l2_detect_cvt(unsigned frame_height,
 408                      unsigned hfreq,
 409                      unsigned vsync,
 410                      unsigned active_width,
 411                      u32 polarities,
 412                      bool interlaced,
 413                      struct v4l2_dv_timings *fmt)
 414 {
 415         int  v_fp, v_bp, h_fp, h_bp, hsync;
 416         int  frame_width, image_height, image_width;
 417         bool reduced_blanking;
 418         bool rb_v2 = false;
 419         unsigned pix_clk;
 420
 421         if (vsync < 4 || vsync > 8)
 422                 return false;
 423
 424         if (polarities == V4L2_DV_VSYNC_POS_POL)
 425                 reduced_blanking = false;
 426         else if (polarities == V4L2_DV_HSYNC_POS_POL)
 427                 reduced_blanking = true;
 428         else
 429                 return false;
 430
 431         if (reduced_blanking && vsync == 8)
 432                 rb_v2 = true;
 433
 434         if (rb_v2 && active_width == 0)
 435                 return false;
 436
 437         if (!rb_v2 && vsync > 7)
 438                 return false;
 439
 440         if (hfreq == 0)
 441                 return false;
 442
 443         /* Vertical */
 444         if (reduced_blanking) {
 445                 if (rb_v2) {
 446                         v_bp = CVT_RB_V_BPORCH;
 447                         v_fp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
 448                         v_fp -= vsync + v_bp;
 449
 450                         if (v_fp < CVT_RB_V2_MIN_V_FPORCH)
 451                                 v_fp = CVT_RB_V2_MIN_V_FPORCH;
 452                 } else {
 453                         v_fp = CVT_RB_V_FPORCH;
 454                         v_bp = (CVT_RB_MIN_V_BLANK * hfreq) / 1000000 + 1;
 455                         v_bp -= vsync + v_fp;
 456
 457                         if (v_bp < CVT_RB_MIN_V_BPORCH)
 458                                 v_bp = CVT_RB_MIN_V_BPORCH;
 459                 }
 460         } else {
 461                 v_fp = CVT_MIN_V_PORCH_RND;
 462                 v_bp = (CVT_MIN_VSYNC_BP * hfreq) / 1000000 + 1 - vsync;
 463
 464                 if (v_bp < CVT_MIN_V_BPORCH)
 465                         v_bp = CVT_MIN_V_BPORCH;
 466         }
 467
 468         if (interlaced)
 469                 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
 470         else
 471                 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 472
 473         if (image_height < 0)
 474                 return false;
 475
 476         /* Aspect ratio based on vsync */
 477         switch (vsync) {
 478         case 4:
 479                 image_width = (image_height * 4) / 3;
 480                 break;
 481         case 5:
 482                 image_width = (image_height * 16) / 9;
 483                 break;
 484         case 6:
 485                 image_width = (image_height * 16) / 10;
 486                 break;
 487         case 7:
 488                 /* special case */
 489                 if (image_height == 1024)
 490                         image_width = (image_height * 5) / 4;
 491                 else if (image_height == 768)
 492                         image_width = (image_height * 15) / 9;
 493                 else
 494                         return false;
 495                 break;
 496         case 8:
 497                 image_width = active_width;
 498                 break;
 499         default:
 500                 return false;
 501         }
 502
 503         if (!rb_v2)
 504                 image_width = image_width & ~7;
 505
 506         /* Horizontal */
 507         if (reduced_blanking) {
 508                 int h_blank;
 509                 int clk_gran;
 510
 511                 h_blank = rb_v2 ? CVT_RB_V2_H_BLANK : CVT_RB_H_BLANK;
 512                 clk_gran = rb_v2 ? CVT_PXL_CLK_GRAN_RB_V2 : CVT_PXL_CLK_GRAN;
 513
 514                 pix_clk = (image_width + h_blank) * hfreq;
 515                 pix_clk = (pix_clk / clk_gran) * clk_gran;
 516
 517                 h_bp  = h_blank / 2;
 518                 hsync = CVT_RB_H_SYNC;
 519                 h_fp  = h_blank - h_bp - hsync;
 520
 521                 frame_width = image_width + h_blank;
 522         } else {
 523                 unsigned ideal_duty_cycle_per_myriad =
 524                         100 * CVT_C_PRIME - (CVT_M_PRIME * 100000) / hfreq;
 525                 int h_blank;
 526
 527                 if (ideal_duty_cycle_per_myriad < 2000)
 528                         ideal_duty_cycle_per_myriad = 2000;
 529
 530                 h_blank = image_width * ideal_duty_cycle_per_myriad /
 531                                         (10000 - ideal_duty_cycle_per_myriad);
 532                 h_blank = (h_blank / (2 * CVT_CELL_GRAN)) * 2 * CVT_CELL_GRAN;
 533
 534                 pix_clk = (image_width + h_blank) * hfreq;
 535                 pix_clk = (pix_clk / CVT_PXL_CLK_GRAN) * CVT_PXL_CLK_GRAN;
 536
 537                 h_bp = h_blank / 2;
 538                 frame_width = image_width + h_blank;
 539
 540                 hsync = frame_width * CVT_HSYNC_PERCENT / 100;
 541                 hsync = (hsync / CVT_CELL_GRAN) * CVT_CELL_GRAN;
 542                 h_fp = h_blank - hsync - h_bp;
 543         }
 544
 545         fmt->type = V4L2_DV_BT_656_1120;
 546         fmt->bt.polarities = polarities;
 547         fmt->bt.width = image_width;
 548         fmt->bt.height = image_height;
 549         fmt->bt.hfrontporch = h_fp;
 550         fmt->bt.vfrontporch = v_fp;
 551         fmt->bt.hsync = hsync;
 552         fmt->bt.vsync = vsync;
 553         fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
 554
 555         if (!interlaced) {
 556                 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
 557                 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
 558         } else {
 559                 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
 560                                       2 * vsync) / 2;
 561                 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
 562                                         2 * vsync - fmt->bt.vbackporch;
 563                 fmt->bt.il_vfrontporch = v_fp;
 564                 fmt->bt.il_vsync = vsync;
 565                 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
 566                 fmt->bt.interlaced = V4L2_DV_INTERLACED;
 567         }
 568
 569         fmt->bt.pixelclock = pix_clk;
 570         fmt->bt.standards = V4L2_DV_BT_STD_CVT;
 571
 572         if (reduced_blanking)
 573                 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
 574
 575         return true;
 576 }
 577 EXPORT_SYMBOL_GPL(v4l2_detect_cvt);
 578
 579 /*
 580  * GTF defines
 581  * Based on Generalized Timing Formula Standard
 582  * Version 1.1 September 2, 1999
 583  */
 584
 585 #define GTF_PXL_CLK_GRAN        250000  /* pixel clock granularity */
 586
 587 #define GTF_MIN_VSYNC_BP        550     /* min time of vsync + back porch (us) */
 588 #define GTF_V_FP                1       /* vertical front porch (lines) */
 589 #define GTF_CELL_GRAN           8       /* character cell granularity */
 590
 591 /* Default */
 592 #define GTF_D_M                 600     /* blanking formula gradient */
 593 #define GTF_D_C                 40      /* blanking formula offset */
 594 #define GTF_D_K                 128     /* blanking formula scaling factor */
 595 #define GTF_D_J                 20      /* blanking formula scaling factor */
 596 #define GTF_D_C_PRIME ((((GTF_D_C - GTF_D_J) * GTF_D_K) / 256) + GTF_D_J)
 597 #define GTF_D_M_PRIME ((GTF_D_K * GTF_D_M) / 256)
 598
 599 /* Secondary */
 600 #define GTF_S_M                 3600    /* blanking formula gradient */
 601 #define GTF_S_C                 40      /* blanking formula offset */
 602 #define GTF_S_K                 128     /* blanking formula scaling factor */
 603 #define GTF_S_J                 35      /* blanking formula scaling factor */
 604 #define GTF_S_C_PRIME ((((GTF_S_C - GTF_S_J) * GTF_S_K) / 256) + GTF_S_J)
 605 #define GTF_S_M_PRIME ((GTF_S_K * GTF_S_M) / 256)
 606
 607 /** v4l2_detect_gtf - detect if the given timings follow the GTF standard
 608  * @frame_height - the total height of the frame (including blanking) in lines.
 609  * @hfreq - the horizontal frequency in Hz.
 610  * @vsync - the height of the vertical sync in lines.
 611  * @polarities - the horizontal and vertical polarities (same as struct
 612  *              v4l2_bt_timings polarities).
 613  * @interlaced - if this flag is true, it indicates interlaced format
 614  * @aspect - preferred aspect ratio. GTF has no method of determining the
 615  *              aspect ratio in order to derive the image width from the
 616  *              image height, so it has to be passed explicitly. Usually
 617  *              the native screen aspect ratio is used for this. If it
 618  *              is not filled in correctly, then 16:9 will be assumed.
 619  * @fmt - the resulting timings.
 620  *
 621  * This function will attempt to detect if the given values correspond to a
 622  * valid GTF format. If so, then it will return true, and fmt will be filled
 623  * in with the found GTF timings.
 624  */
 625 bool v4l2_detect_gtf(unsigned frame_height,
 626                 unsigned hfreq,
 627                 unsigned vsync,
 628                 u32 polarities,
 629                 bool interlaced,
 630                 struct v4l2_fract aspect,
 631                 struct v4l2_dv_timings *fmt)
 632 {
 633         int pix_clk;
 634         int  v_fp, v_bp, h_fp, hsync;
 635         int frame_width, image_height, image_width;
 636         bool default_gtf;
 637         int h_blank;
 638
 639         if (vsync != 3)
 640                 return false;
 641
 642         if (polarities == V4L2_DV_VSYNC_POS_POL)
 643                 default_gtf = true;
 644         else if (polarities == V4L2_DV_HSYNC_POS_POL)
 645                 default_gtf = false;
 646         else
 647                 return false;
 648
 649         if (hfreq == 0)
 650                 return false;
 651
 652         /* Vertical */
 653         v_fp = GTF_V_FP;
 654         v_bp = (GTF_MIN_VSYNC_BP * hfreq + 500000) / 1000000 - vsync;
 655         if (interlaced)
 656                 image_height = (frame_height - 2 * v_fp - 2 * vsync - 2 * v_bp) & ~0x1;
 657         else
 658                 image_height = (frame_height - v_fp - vsync - v_bp + 1) & ~0x1;
 659
 660         if (image_height < 0)
 661                 return false;
 662
 663         if (aspect.numerator == 0 || aspect.denominator == 0) {
 664                 aspect.numerator = 16;
 665                 aspect.denominator = 9;
 666         }
 667         image_width = ((image_height * aspect.numerator) / aspect.denominator);
 668         image_width = (image_width + GTF_CELL_GRAN/2) & ~(GTF_CELL_GRAN - 1);
 669
 670         /* Horizontal */
 671         if (default_gtf) {
 672                 u64 num;
 673                 u32 den;
 674
 675                 num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) -
 676                       ((u64)image_width * GTF_D_M_PRIME * 1000));
 677                 den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) *
 678                       (2 * GTF_CELL_GRAN);
 679                 h_blank = div_u64((num + (den >> 1)), den);
 680                 h_blank *= (2 * GTF_CELL_GRAN);
 681         } else {
 682                 u64 num;
 683                 u32 den;
 684
 685                 num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) -
 686                       ((u64)image_width * GTF_S_M_PRIME * 1000));
 687                 den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) *
 688                       (2 * GTF_CELL_GRAN);
 689                 h_blank = div_u64((num + (den >> 1)), den);
 690                 h_blank *= (2 * GTF_CELL_GRAN);
 691         }
 692
 693         frame_width = image_width + h_blank;
 694
 695         pix_clk = (image_width + h_blank) * hfreq;
 696         pix_clk = pix_clk / GTF_PXL_CLK_GRAN * GTF_PXL_CLK_GRAN;
 697
 698         hsync = (frame_width * 8 + 50) / 100;
 699         hsync = ((hsync + GTF_CELL_GRAN / 2) / GTF_CELL_GRAN) * GTF_CELL_GRAN;
 700
 701         h_fp = h_blank / 2 - hsync;
 702
 703         fmt->type = V4L2_DV_BT_656_1120;
 704         fmt->bt.polarities = polarities;
 705         fmt->bt.width = image_width;
 706         fmt->bt.height = image_height;
 707         fmt->bt.hfrontporch = h_fp;
 708         fmt->bt.vfrontporch = v_fp;
 709         fmt->bt.hsync = hsync;
 710         fmt->bt.vsync = vsync;
 711         fmt->bt.hbackporch = frame_width - image_width - h_fp - hsync;
 712
 713         if (!interlaced) {
 714                 fmt->bt.vbackporch = frame_height - image_height - v_fp - vsync;
 715                 fmt->bt.interlaced = V4L2_DV_PROGRESSIVE;
 716         } else {
 717                 fmt->bt.vbackporch = (frame_height - image_height - 2 * v_fp -
 718                                       2 * vsync) / 2;
 719                 fmt->bt.il_vbackporch = frame_height - image_height - 2 * v_fp -
 720                                         2 * vsync - fmt->bt.vbackporch;
 721                 fmt->bt.il_vfrontporch = v_fp;
 722                 fmt->bt.il_vsync = vsync;
 723                 fmt->bt.flags |= V4L2_DV_FL_HALF_LINE;
 724                 fmt->bt.interlaced = V4L2_DV_INTERLACED;
 725         }
 726
 727         fmt->bt.pixelclock = pix_clk;
 728         fmt->bt.standards = V4L2_DV_BT_STD_GTF;
 729
 730         if (!default_gtf)
 731                 fmt->bt.flags |= V4L2_DV_FL_REDUCED_BLANKING;
 732
 733         return true;
 734 }
 735 EXPORT_SYMBOL_GPL(v4l2_detect_gtf);
 736
 737 /** v4l2_calc_aspect_ratio - calculate the aspect ratio based on bytes
 738  *      0x15 and 0x16 from the EDID.
 739  * @hor_landscape - byte 0x15 from the EDID.
 740  * @vert_portrait - byte 0x16 from the EDID.
 741  *
 742  * Determines the aspect ratio from the EDID.
 743  * See VESA Enhanced EDID standard, release A, rev 2, section 3.6.2:
 744  * "Horizontal and Vertical Screen Size or Aspect Ratio"
 745  */
 746 struct v4l2_fract v4l2_calc_aspect_ratio(u8 hor_landscape, u8 vert_portrait)
 747 {
 748         struct v4l2_fract aspect = { 16, 9 };
 749         u8 ratio;
 750
 751         /* Nothing filled in, fallback to 16:9 */
 752         if (!hor_landscape && !vert_portrait)
 753                 return aspect;
 754         /* Both filled in, so they are interpreted as the screen size in cm */
 755         if (hor_landscape && vert_portrait) {
 756                 aspect.numerator = hor_landscape;
 757                 aspect.denominator = vert_portrait;
 758                 return aspect;
 759         }
 760         /* Only one is filled in, so interpret them as a ratio:
 761            (val + 99) / 100 */
 762         ratio = hor_landscape | vert_portrait;
 763         /* Change some rounded values into the exact aspect ratio */
 764         if (ratio == 79) {
 765                 aspect.numerator = 16;
 766                 aspect.denominator = 9;
 767         } else if (ratio == 34) {
 768                 aspect.numerator = 4;
 769                 aspect.denominator = 3;
 770         } else if (ratio == 68) {
 771                 aspect.numerator = 15;
 772                 aspect.denominator = 9;
 773         } else {
 774                 aspect.numerator = hor_landscape + 99;
 775                 aspect.denominator = 100;
 776         }
 777         if (hor_landscape)
 778                 return aspect;
 779         /* The aspect ratio is for portrait, so swap numerator and denominator */
 780         swap(aspect.denominator, aspect.numerator);
 781         return aspect;
 782 }
 783 EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);