vidix/sis_bridge.c

   1 /*
   2  * VIDIX driver for SiS chipsets.
   3  * Video bridge detection for SiS 300 and 310/325 series.
   4  *
   5  * Copyright (C) 2003 Jake Page, Sugar Media
   6  * Based on SiS Xv driver
   7  * Copyright 2002-2003 by Thomas Winischhofer, Vienna, Austria
   8  *
   9  * This file is part of MPlayer.
  10  *
  11  * MPlayer is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * MPlayer is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29
  30 #include "dha.h"
  31 #include "sis_bridge.h"
  32 #include "sis_regs.h"
  33 #include "sis_defs.h"
  34
  35
  36 static void sis_ddc2_delay(unsigned short delaytime)
  37 {
  38     unsigned short i;
  39     int temp;
  40
  41     for (i = 0; i < delaytime; i++) {
  42         inSISIDXREG(SISSR, 0x05, temp);
  43     }
  44 }
  45
  46
  47 static int sis_do_sense(int tempbl, int tempbh, int tempcl, int tempch)
  48 {
  49     int temp;
  50
  51     outSISIDXREG(SISPART4, 0x11, tempbl);
  52     temp = tempbh | tempcl;
  53     setSISIDXREG(SISPART4, 0x10, 0xe0, temp);
  54     //usleep(200000);
  55     sis_ddc2_delay(0x1000);
  56     tempch &= 0x7f;
  57     inSISIDXREG(SISPART4, 0x03, temp);
  58     temp ^= 0x0e;
  59     temp &= tempch;
  60     return temp == tempch;
  61 }
  62
  63
  64 /* sense connected devices on 30x bridge */
  65 static void sis_sense_30x(void)
  66 {
  67     unsigned char backupP4_0d, backupP2_00, biosflag;
  68     unsigned char testsvhs_tempbl, testsvhs_tempbh;
  69     unsigned char testsvhs_tempcl, testsvhs_tempch;
  70     unsigned char testcvbs_tempbl, testcvbs_tempbh;
  71     unsigned char testcvbs_tempcl, testcvbs_tempch;
  72     unsigned char testvga2_tempbl, testvga2_tempbh;
  73     unsigned char testvga2_tempcl, testvga2_tempch;
  74     int myflag, result = 0, i, j, haveresult;
  75
  76     inSISIDXREG(SISPART4, 0x0d, backupP4_0d);
  77     outSISIDXREG(SISPART4, 0x0d, (backupP4_0d | 0x04));
  78
  79     inSISIDXREG(SISPART2, 0x00, backupP2_00);
  80     outSISIDXREG(SISPART2, 0x00, (backupP2_00 | 0x1c));
  81
  82     sis_do_sense(0, 0, 0, 0);
  83
  84     if (sis_vga_engine == SIS_300_VGA) {
  85             testvga2_tempbh = 0x00;
  86             testvga2_tempbl = 0xd1;
  87             testsvhs_tempbh = 0x00;
  88             testsvhs_tempbl = 0xb9;
  89             testcvbs_tempbh = 0x00;
  90             testcvbs_tempbl = 0xb3;
  91             biosflag = 0;
  92
  93         if (sis_vbflags & (VB_301B | VB_302B | VB_301LV | VB_302LV)) {
  94             testvga2_tempbh = 0x01;
  95             testvga2_tempbl = 0x90;
  96             testsvhs_tempbh = 0x01;
  97             testsvhs_tempbl = 0x6b;
  98             testcvbs_tempbh = 0x01;
  99             testcvbs_tempbl = 0x74;
 100         }
 101         inSISIDXREG(SISPART4, 0x01, myflag);
 102         if (myflag & 0x04) {
 103             testvga2_tempbh = 0x00;
 104             testvga2_tempbl = 0xfd;
 105             testsvhs_tempbh = 0x00;
 106             testsvhs_tempbl = 0xdd;
 107             testcvbs_tempbh = 0x00;
 108             testcvbs_tempbl = 0xee;
 109         }
 110         testvga2_tempch = 0x0e;
 111         testvga2_tempcl = 0x08;
 112         testsvhs_tempch = 0x06;
 113         testsvhs_tempcl = 0x04;
 114         testcvbs_tempch = 0x08;
 115         testcvbs_tempcl = 0x04;
 116
 117         if (sis_device_id == DEVICE_SIS_300) {
 118             inSISIDXREG(SISSR, 0x3b, myflag);
 119             if (!(myflag & 0x01)) {
 120                 testvga2_tempbh = 0x00;
 121                 testvga2_tempbl = 0x00;
 122                 testvga2_tempch = 0x00;
 123                 testvga2_tempcl = 0x00;
 124             }
 125         }
 126     } else {
 127             testvga2_tempbh = 0x00;
 128             testvga2_tempbl = 0xd1;
 129             testsvhs_tempbh = 0x00;
 130             testsvhs_tempbl = 0xb9;
 131             testcvbs_tempbh = 0x00;
 132             testcvbs_tempbl = 0xb3;
 133             biosflag = 0;
 134
 135         if (sis_vbflags & (VB_301B | VB_302B | VB_301LV | VB_302LV)) {
 136                 if (sis_vbflags & (VB_301B | VB_302B)) {
 137                     testvga2_tempbh = 0x01;
 138                     testvga2_tempbl = 0x90;
 139                     testsvhs_tempbh = 0x01;
 140                     testsvhs_tempbl = 0x6b;
 141                     testcvbs_tempbh = 0x01;
 142                     testcvbs_tempbl = 0x74;
 143                 } else {
 144                     testvga2_tempbh = 0x00;
 145                     testvga2_tempbl = 0x00;
 146                     testsvhs_tempbh = 0x02;
 147                     testsvhs_tempbl = 0x00;
 148                     testcvbs_tempbh = 0x01;
 149                     testcvbs_tempbl = 0x00;
 150                 }
 151         }
 152         if (sis_vbflags & (VB_301 | VB_301B | VB_302B)) {
 153             inSISIDXREG(SISPART4, 0x01, myflag);
 154             if (myflag & 0x04) {
 155                 testvga2_tempbh = 0x00;
 156                 testvga2_tempbl = 0xfd;
 157                 testsvhs_tempbh = 0x00;
 158                 testsvhs_tempbl = 0xdd;
 159                 testcvbs_tempbh = 0x00;
 160                 testcvbs_tempbl = 0xee;
 161             }
 162         }
 163         if (sis_vbflags & (VB_301LV | VB_302LV)) {
 164             /* TW: No VGA2 or SCART on LV bridges */
 165             testvga2_tempbh = 0x00;
 166             testvga2_tempbl = 0x00;
 167             testvga2_tempch = 0x00;
 168             testvga2_tempcl = 0x00;
 169             testsvhs_tempch = 0x04;
 170             testsvhs_tempcl = 0x08;
 171             testcvbs_tempch = 0x08;
 172             testcvbs_tempcl = 0x08;
 173         } else {
 174             testvga2_tempch = 0x0e;
 175             testvga2_tempcl = 0x08;
 176             testsvhs_tempch = 0x06;
 177             testsvhs_tempcl = 0x04;
 178             testcvbs_tempch = 0x08;
 179             testcvbs_tempcl = 0x04;
 180         }
 181     }
 182
 183     /* XXX: ?? andSISIDXREG(SISCR, 0x32, ~0x14); */
 184     /* pSiS->postVBCR32 &= ~0x14; */
 185
 186     /* scan for VGA2/SCART */
 187     if (testvga2_tempch || testvga2_tempcl ||
 188         testvga2_tempbh || testvga2_tempbl) {
 189
 190         haveresult = 0;
 191         for (j = 0; j < 10; j++) {
 192             result = 0;
 193             for (i = 0; i < 3; i++) {
 194                 if (sis_do_sense(testvga2_tempbl, testvga2_tempbh,
 195                                  testvga2_tempcl, testvga2_tempch))
 196                     result++;
 197             }
 198             if ((result == 0) || (result >= 2))
 199                 break;
 200         }
 201         if (result) {
 202             if (biosflag & 0x01) {
 203                 if (sis_verbose > 1) {
 204                     printf
 205                         ("[SiS] SiS30x: Detected TV connected to SCART output\n");
 206                 }
 207                 sis_vbflags |= TV_SCART;
 208                 orSISIDXREG(SISCR, 0x32, 0x04);
 209                 /*pSiS->postVBCR32 |= 0x04; */
 210             } else {
 211                 if (sis_verbose > 1) {
 212                     printf
 213                         ("[SiS] SiS30x: Detected secondary VGA connection\n");
 214                 }
 215                 sis_vbflags |= VGA2_CONNECTED;
 216                 orSISIDXREG(SISCR, 0x32, 0x10);
 217                 /*pSiS->postVBCR32 |= 0x10; */
 218             }
 219         }
 220     }
 221
 222     /* scanning for TV */
 223
 224     /* XXX: ?? andSISIDXREG(SISCR, 0x32, ~0x03); */
 225     /* pSiS->postVBCR32 &= ~0x03; */
 226
 227     result = sis_do_sense(testsvhs_tempbl, testsvhs_tempbh,
 228                           testsvhs_tempcl, testsvhs_tempch);
 229
 230
 231     haveresult = 0;
 232     for (j = 0; j < 10; j++) {
 233         result = 0;
 234         for (i = 0; i < 3; i++) {
 235             if (sis_do_sense(testsvhs_tempbl, testsvhs_tempbh,
 236                              testsvhs_tempcl, testsvhs_tempch))
 237                 result++;
 238         }
 239         if ((result == 0) || (result >= 2))
 240             break;
 241     }
 242     if (result) {
 243         if (sis_verbose > 1) {
 244             printf
 245                 ("[SiS] SiS30x: Detected TV connected to SVIDEO output\n");
 246         }
 247         /* TW: So we can be sure that there IS a SVIDEO output */
 248         sis_vbflags |= TV_SVIDEO;
 249         orSISIDXREG(SISCR, 0x32, 0x02);
 250         //pSiS->postVBCR32 |= 0x02;
 251     }
 252
 253     if ((biosflag & 0x02) || (!(result))) {
 254         haveresult = 0;
 255         for (j = 0; j < 10; j++) {
 256             result = 0;
 257             for (i = 0; i < 3; i++) {
 258                 if (sis_do_sense(testcvbs_tempbl, testcvbs_tempbh,
 259                                  testcvbs_tempcl, testcvbs_tempch))
 260                     result++;
 261             }
 262             if ((result == 0) || (result >= 2))
 263                 break;
 264         }
 265         if (result) {
 266             if (sis_verbose > 1) {
 267                 printf
 268                     ("[SiS] SiS30x: Detected TV connected to COMPOSITE output\n");
 269             }
 270             sis_vbflags |= TV_AVIDEO;
 271             orSISIDXREG(SISCR, 0x32, 0x01);
 272             //pSiS->postVBCR32 |= 0x01;
 273         }
 274     }
 275
 276     sis_do_sense(0, 0, 0, 0);
 277
 278     outSISIDXREG(SISPART2, 0x00, backupP2_00);
 279     outSISIDXREG(SISPART4, 0x0d, backupP4_0d);
 280 }
 281
 282
 283 static void sis_detect_crt1(void)
 284 {
 285     unsigned char CR32;
 286     unsigned char CRT1Detected = 0;
 287     unsigned char OtherDevices = 0;
 288
 289     if (!(sis_vbflags & VB_VIDEOBRIDGE)) {
 290         sis_crt1_off = 0;
 291         return;
 292     }
 293
 294     inSISIDXREG(SISCR, 0x32, CR32);
 295
 296     if (CR32 & 0x20)
 297         CRT1Detected = 1;
 298     if (CR32 & 0x5F)
 299         OtherDevices = 1;
 300
 301     if (sis_crt1_off == -1) {
 302         if (!CRT1Detected) {
 303             /* BIOS detected no CRT1. */
 304             /* If other devices exist, switch it off */
 305             if (OtherDevices)
 306                 sis_crt1_off = 1;
 307             else
 308                 sis_crt1_off = 0;
 309         } else {
 310             /* BIOS detected CRT1, leave/switch it on */
 311             sis_crt1_off = 0;
 312         }
 313     }
 314     if (sis_verbose > 0) {
 315         printf("[SiS] %sCRT1 connection detected\n",
 316                sis_crt1_off ? "No " : "");
 317     }
 318 }
 319
 320 static void sis_detect_tv(void)
 321 {
 322     unsigned char SR16, SR38, CR32, CR38 = 0, CR79;
 323     int temp = 0;
 324
 325     if (!(sis_vbflags & VB_VIDEOBRIDGE))
 326         return;
 327
 328     inSISIDXREG(SISCR, 0x32, CR32);
 329     inSISIDXREG(SISSR, 0x16, SR16);
 330     inSISIDXREG(SISSR, 0x38, SR38);
 331     switch (sis_vga_engine) {
 332     case SIS_300_VGA:
 333         if (sis_device_id == DEVICE_SIS_630_VGA)
 334             temp = 0x35;
 335         break;
 336     case SIS_315_VGA:
 337         temp = 0x38;
 338         break;
 339     }
 340     if (temp) {
 341         inSISIDXREG(SISCR, temp, CR38);
 342     }
 343
 344     if (CR32 & 0x47)
 345         sis_vbflags |= CRT2_TV;
 346
 347     if (CR32 & 0x04)
 348         sis_vbflags |= TV_SCART;
 349     else if (CR32 & 0x02)
 350         sis_vbflags |= TV_SVIDEO;
 351     else if (CR32 & 0x01)
 352         sis_vbflags |= TV_AVIDEO;
 353     else if (CR32 & 0x40)
 354         sis_vbflags |= (TV_SVIDEO | TV_HIVISION);
 355     else if ((CR38 & 0x04) && (sis_vbflags & (VB_301LV | VB_302LV)))
 356         sis_vbflags |= TV_HIVISION_LV;
 357     else if ((CR38 & 0x04) && (sis_vbflags & VB_CHRONTEL))
 358         sis_vbflags |= (TV_CHSCART | TV_PAL);
 359     else if ((CR38 & 0x08) && (sis_vbflags & VB_CHRONTEL))
 360         sis_vbflags |= (TV_CHHDTV | TV_NTSC);
 361
 362     if (sis_vbflags & (TV_SCART | TV_SVIDEO | TV_AVIDEO | TV_HIVISION)) {
 363         if (sis_vga_engine == SIS_300_VGA) {
 364             /* TW: Should be SR38 here as well, but this
 365              *     does not work. Looks like a BIOS bug (2.04.5c).
 366              */
 367             if (SR16 & 0x20)
 368                 sis_vbflags |= TV_PAL;
 369             else
 370                 sis_vbflags |= TV_NTSC;
 371         } else if ((sis_device_id == DEVICE_SIS_550_VGA)) {
 372             inSISIDXREG(SISCR, 0x79, CR79);
 373             if (CR79 & 0x08) {
 374                 inSISIDXREG(SISCR, 0x79, CR79);
 375                 CR79 >>= 5;
 376             }
 377             if (CR79 & 0x01) {
 378                 sis_vbflags |= TV_PAL;
 379                 if (CR38 & 0x40)
 380                     sis_vbflags |= TV_PALM;
 381                 else if (CR38 & 0x80)
 382                     sis_vbflags |= TV_PALN;
 383             } else
 384                 sis_vbflags |= TV_NTSC;
 385         } else if ((sis_device_id == DEVICE_SIS_650_VGA)) {
 386             inSISIDXREG(SISCR, 0x79, CR79);
 387             if (CR79 & 0x20) {
 388                 sis_vbflags |= TV_PAL;
 389                 if (CR38 & 0x40)
 390                     sis_vbflags |= TV_PALM;
 391                 else if (CR38 & 0x80)
 392                     sis_vbflags |= TV_PALN;
 393             } else
 394                 sis_vbflags |= TV_NTSC;
 395         } else {                /* 315, 330 */
 396             if (SR38 & 0x01) {
 397                 sis_vbflags |= TV_PAL;
 398                 if (CR38 & 0x40)
 399                     sis_vbflags |= TV_PALM;
 400                 else if (CR38 & 0x80)
 401                     sis_vbflags |= TV_PALN;
 402             } else
 403                 sis_vbflags |= TV_NTSC;
 404         }
 405     }
 406
 407     if (sis_vbflags &
 408         (TV_SCART | TV_SVIDEO | TV_AVIDEO | TV_HIVISION | TV_CHSCART |
 409          TV_CHHDTV)) {
 410         if (sis_verbose > 0) {
 411             printf("[SiS] %sTV standard %s\n",
 412                    (sis_vbflags & (TV_CHSCART | TV_CHHDTV)) ? "Using " :
 413                    "Detected default ",
 414                    (sis_vbflags & TV_NTSC) ? ((sis_vbflags & TV_CHHDTV) ?
 415                                               "480i HDTV" : "NTSC")
 416                    : ((sis_vbflags & TV_PALM) ? "PALM"
 417                       : ((sis_vbflags & TV_PALN) ? "PALN" : "PAL")));
 418         }
 419     }
 420
 421 }
 422
 423
 424 static void sis_detect_crt2(void)
 425 {
 426     unsigned char CR32;
 427
 428     if (!(sis_vbflags & VB_VIDEOBRIDGE))
 429         return;
 430
 431     /* CRT2-VGA not supported on LVDS and 30xLV */
 432     if (sis_vbflags & (VB_LVDS | VB_301LV | VB_302LV))
 433         return;
 434
 435     inSISIDXREG(SISCR, 0x32, CR32);
 436
 437     if (CR32 & 0x10)
 438         sis_vbflags |= CRT2_VGA;
 439 }
 440
 441
 442 /* Preinit: detect video bridge and sense connected devs */
 443 static void sis_detect_video_bridge(void)
 444 {
 445     int temp, temp1, temp2;
 446
 447
 448     sis_vbflags = 0;
 449
 450     if (sis_vga_engine != SIS_300_VGA && sis_vga_engine != SIS_315_VGA)
 451         return;
 452
 453     inSISIDXREG(SISPART4, 0x00, temp);
 454     temp &= 0x0F;
 455     if (temp == 1) {
 456         inSISIDXREG(SISPART4, 0x01, temp1);
 457         temp1 &= 0xff;
 458         if (temp1 >= 0xE0) {
 459             sis_vbflags |= VB_302LV;
 460             //pSiS->sishw_ext.ujVBChipID = VB_CHIP_302LV;
 461             if (sis_verbose > 1) {
 462                 printf
 463                     ("[SiS] Detected SiS302LV video bridge (ID 1; Revision 0x%x)\n",
 464                      temp1);
 465             }
 466
 467         } else if (temp1 >= 0xD0) {
 468             sis_vbflags |= VB_301LV;
 469             //pSiS->sishw_ext.ujVBChipID = VB_CHIP_301LV;
 470             if (sis_verbose > 1) {
 471                 printf
 472                     ("[SiS] Detected SiS301LV video bridge (ID 1; Revision 0x%x)\n",
 473                      temp1);
 474             }
 475         } else if (temp1 >= 0xB0) {
 476             sis_vbflags |= VB_301B;
 477             //pSiS->sishw_ext.ujVBChipID = VB_CHIP_301B;
 478             inSISIDXREG(SISPART4, 0x23, temp2);
 479             if (!(temp2 & 0x02))
 480                 sis_vbflags |= VB_30xBDH;
 481             if (sis_verbose > 1) {
 482                 printf
 483                     ("[SiS] Detected SiS301B%s video bridge (Revision 0x%x)\n",
 484                      (temp2 & 0x02) ? "" : " (DH)", temp1);
 485             }
 486         } else {
 487             sis_vbflags |= VB_301;
 488             //pSiS->sishw_ext.ujVBChipID = VB_CHIP_301;
 489             if (sis_verbose > 1) {
 490                 printf
 491                     ("[SiS] Detected SiS301 video bridge (Revision 0x%x)\n",
 492                      temp1);
 493             }
 494         }
 495
 496         sis_sense_30x();
 497
 498     } else if (temp == 2) {
 499
 500         inSISIDXREG(SISPART4, 0x01, temp1);
 501         temp1 &= 0xff;
 502         if (temp1 >= 0xE0) {
 503             sis_vbflags |= VB_302LV;
 504             //pSiS->sishw_ext.ujVBChipID = VB_CHIP_302LV;
 505             if (sis_verbose > 1) {
 506                 printf
 507                     ("[SiS] Detected SiS302LV video bridge (ID 2; Revision 0x%x)\n",
 508                      temp1);
 509             }
 510         } else if (temp1 >= 0xD0) {
 511             sis_vbflags |= VB_301LV;
 512             //pSiS->sishw_ext.ujVBChipID = VB_CHIP_301LV;
 513             if (sis_verbose > 1) {
 514                 printf
 515                     ("[SiS] Detected SiS301LV video bridge (ID 2; Revision 0x%x)\n",
 516                      temp1);
 517             }
 518         } else {
 519             sis_vbflags |= VB_302B;
 520             //pSiS->sishw_ext.ujVBChipID = VB_CHIP_302B;
 521             inSISIDXREG(SISPART4, 0x23, temp2);
 522             if (!(temp & 0x02))
 523                 sis_vbflags |= VB_30xBDH;
 524             if (sis_verbose > 1) {
 525                 printf
 526                     ("[SiS] Detected SiS302B%s video bridge (Revision 0x%x)\n",
 527                      (temp2 & 0x02) ? "" : " (DH)", temp1);
 528             }
 529         }
 530
 531         sis_sense_30x();
 532
 533     } else if (temp == 3) {
 534         if (sis_verbose > 1) {
 535             printf("[SiS] Detected SiS303 video bridge - not supported\n");
 536         }
 537     } else {
 538         /* big scary mess of code to handle unknown or Chrontel LVDS */
 539         /* skipping it for now */
 540         if (sis_verbose > 1) {
 541             printf
 542                 ("[SiS] Detected Chrontel video bridge - not supported\n");
 543         }
 544     }
 545
 546     /* this is probably not relevant to video overlay driver... */
 547     /* detects if brdige uses LCDA for low res text modes */
 548     if (sis_vga_engine == SIS_315_VGA) {
 549         if (sis_vbflags & (VB_302B | VB_301LV | VB_302LV)) {
 550                 inSISIDXREG(SISCR, 0x34, temp);
 551                 if (temp <= 0x13) {
 552                     inSISIDXREG(SISCR, 0x38, temp);
 553                     if ((temp & 0x03) == 0x03) {
 554                         //pSiS->SiS_Pr->SiS_UseLCDA = TRUE;
 555                         sis_vbflags |= VB_USELCDA;
 556                     } else {
 557                         inSISIDXREG(SISCR, 0x30, temp);
 558                         if (temp & 0x20) {
 559                             inSISIDXREG(SISPART1, 0x13, temp);
 560                             if (temp & 0x40) {
 561                                 //pSiS->SiS_Pr->SiS_UseLCDA = TRUE;
 562                                 sis_vbflags |= VB_USELCDA;
 563                             }
 564                         }
 565                     }
 566                 }
 567             if (sis_vbflags & VB_USELCDA) {
 568                 /* printf("Bridge uses LCDA for low resolution and text modes\n"); */
 569             }
 570         }
 571     }
 572
 573
 574 }
 575
 576
 577 /* detect video bridge type and sense connected devices */
 578 void sis_init_video_bridge(void)
 579 {
 580
 581     sis_detect_video_bridge();
 582
 583     sis_detect_crt1();
 584     //sis_detect_lcd();
 585     sis_detect_tv();
 586     sis_detect_crt2();
 587
 588     sis_detected_crt2_devices =
 589         sis_vbflags & (CRT2_LCD | CRT2_TV | CRT2_VGA);
 590
 591     // force crt2 type
 592     if (sis_force_crt2_type == CRT2_DEFAULT) {
 593         if (sis_vbflags & CRT2_VGA)
 594             sis_force_crt2_type = CRT2_VGA;
 595         else if (sis_vbflags & CRT2_LCD)
 596             sis_force_crt2_type = CRT2_LCD;
 597         else if (sis_vbflags & CRT2_TV)
 598             sis_force_crt2_type = CRT2_TV;
 599     }
 600
 601     switch (sis_force_crt2_type) {
 602     case CRT2_TV:
 603         sis_vbflags = sis_vbflags & ~(CRT2_LCD | CRT2_VGA);
 604         if (sis_vbflags & VB_VIDEOBRIDGE)
 605             sis_vbflags = sis_vbflags | CRT2_TV;
 606         else
 607             sis_vbflags = sis_vbflags & ~(CRT2_TV);
 608         break;
 609     case CRT2_LCD:
 610         sis_vbflags = sis_vbflags & ~(CRT2_TV | CRT2_VGA);
 611         if ((sis_vbflags & VB_VIDEOBRIDGE) /* XXX: && (pSiS->VBLCDFlags) */
 612             )
 613             sis_vbflags = sis_vbflags | CRT2_LCD;
 614         else {
 615             sis_vbflags = sis_vbflags & ~(CRT2_LCD);
 616             if (sis_verbose > 0) {
 617                 printf
 618                     ("[SiS] Can't force CRT2 to LCD, no panel detected\n");
 619             }
 620         }
 621         break;
 622     case CRT2_VGA:
 623         if (sis_vbflags & VB_LVDS) {
 624             if (sis_verbose > 0) {
 625                 printf("[SiS] LVDS does not support secondary VGA\n");
 626             }
 627             break;
 628         }
 629         if (sis_vbflags & (VB_301LV | VB_302LV)) {
 630             if (sis_verbose > 0) {
 631                 printf
 632                     ("[SiS] SiS30xLV bridge does not support secondary VGA\n");
 633             }
 634             break;
 635         }
 636         sis_vbflags = sis_vbflags & ~(CRT2_TV | CRT2_LCD);
 637         if (sis_vbflags & VB_VIDEOBRIDGE)
 638             sis_vbflags = sis_vbflags | CRT2_VGA;
 639         else
 640             sis_vbflags = sis_vbflags & ~(CRT2_VGA);
 641         break;
 642     default:
 643         sis_vbflags &= ~(CRT2_TV | CRT2_LCD | CRT2_VGA);
 644     }
 645
 646     /* CRT2 gamma correction?? */
 647
 648     /* other force modes: */
 649     /*  have a 'force tv type' (svideo, composite, scart) option? */
 650     /*  have a 'force crt1 type' (to turn it off, etc??) */
 651
 652     /* TW: Check if CRT1 used (or needed; this eg. if no CRT2 detected) */
 653     if (sis_vbflags & VB_VIDEOBRIDGE) {
 654
 655         /* TW: No CRT2 output? Then we NEED CRT1!
 656          *     We also need CRT1 if depth = 8 and bridge=LVDS|630+301B
 657          */
 658         if ((!(sis_vbflags & (CRT2_VGA | CRT2_LCD | CRT2_TV))) || (     /*(pScrn->bitsPerPixel == 8) && */
 659                                                                       ((sis_vbflags & (VB_LVDS | VB_CHRONTEL)) || ((sis_vga_engine == SIS_300_VGA) && (sis_vbflags & VB_301B))))) {
 660             sis_crt1_off = 0;
 661         }
 662         /* TW: No CRT2 output? Then we can't use hw overlay on CRT2 */
 663         if (!(sis_vbflags & (CRT2_VGA | CRT2_LCD | CRT2_TV)))
 664             sis_overlay_on_crt1 = 1;
 665
 666     } else {                    /* TW: no video bridge? */
 667
 668         /* Then we NEED CRT1... */
 669         sis_crt1_off = 0;
 670         /* ... and can't use CRT2 for overlay output */
 671         sis_overlay_on_crt1 = 1;
 672     }
 673
 674     /* tvstandard options ? */
 675
 676     // determine using CRT1 or CRT2?
 677     /* -> NO dualhead right now... */
 678     if (sis_vbflags & DISPTYPE_DISP2) {
 679         if (sis_crt1_off) {
 680             sis_vbflags |= VB_DISPMODE_SINGLE;
 681             /* TW: No CRT1? Then we use the video overlay on CRT2 */
 682             sis_overlay_on_crt1 = 0;
 683         } else                  /* TW: CRT1 and CRT2 - mirror or dual head ----- */
 684             sis_vbflags |= (VB_DISPMODE_MIRROR | DISPTYPE_CRT1);
 685     } else {                    /* TW: CRT1 only ------------------------------- */
 686         sis_vbflags |= (VB_DISPMODE_SINGLE | DISPTYPE_CRT1);
 687     }
 688
 689     if (sis_verbose > 0) {
 690         printf("[SiS] Using hardware overlay on CRT%d\n",
 691                sis_overlay_on_crt1 ? 1 : 2);
 692     }
 693
 694 }