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