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/videodev2.h>
  26#include <linux/v4l2-dv-timings.h>
  27#include <media/v4l2-dv-timings.h>
  28#include <linux/math64.h>
  29
  30MODULE_AUTHOR("Hans Verkuil");
  31MODULE_DESCRIPTION("V4L2 DV Timings Helper Functions");
  32MODULE_LICENSE("GPL");
  33
  34const 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};
 148EXPORT_SYMBOL_GPL(v4l2_dv_timings_presets);
 149
 150bool 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}
 176EXPORT_SYMBOL_GPL(v4l2_valid_dv_timings);
 177
 178int 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}
 196EXPORT_SYMBOL_GPL(v4l2_enum_dv_timings_cap);
 197
 198bool 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}
 225EXPORT_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 */
 237bool 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}
 265EXPORT_SYMBOL_GPL(v4l2_match_dv_timings);
 266
 267void 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}
 328EXPORT_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 */
 382bool 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}
 552EXPORT_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 */
 600bool 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}
 710EXPORT_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 */
 721struct 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}
 758EXPORT_SYMBOL_GPL(v4l2_calc_aspect_ratio);
 759