release/src-rt-6.x/linux/linux-2.6/drivers/video/kyro/STG4000OverlayDevice.c

   1 /*
   2  *  linux/drivers/video/kyro/STG4000OverlayDevice.c
   3  *
   4  *  Copyright (C) 2000 Imagination Technologies Ltd
   5  *  Copyright (C) 2002 STMicroelectronics
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License.  See the file COPYING in the main directory of this archive
   9  * for more details.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/types.h>
  15
  16 #include "STG4000Reg.h"
  17 #include "STG4000Interface.h"
  18
  19 /* HW Defines */
  20
  21 #define STG4000_NO_SCALING    0x800
  22 #define STG4000_NO_DECIMATION 0xFFFFFFFF
  23
  24 /* Primary surface */
  25 #define STG4000_PRIM_NUM_PIX   5
  26 #define STG4000_PRIM_ALIGN     4
  27 #define STG4000_PRIM_ADDR_BITS 20
  28
  29 #define STG4000_PRIM_MIN_WIDTH  640
  30 #define STG4000_PRIM_MAX_WIDTH  1600
  31 #define STG4000_PRIM_MIN_HEIGHT 480
  32 #define STG4000_PRIM_MAX_HEIGHT 1200
  33
  34 /* Overlay surface */
  35 #define STG4000_OVRL_NUM_PIX   4
  36 #define STG4000_OVRL_ALIGN     2
  37 #define STG4000_OVRL_ADDR_BITS 20
  38 #define STG4000_OVRL_NUM_MODES 5
  39
  40 #define STG4000_OVRL_MIN_WIDTH  0
  41 #define STG4000_OVRL_MAX_WIDTH  720
  42 #define STG4000_OVRL_MIN_HEIGHT 0
  43 #define STG4000_OVRL_MAX_HEIGHT 576
  44
  45 /* Decimation and Scaling */
  46 static u32 adwDecim8[33] = {
  47             0xffffffff, 0xfffeffff, 0xffdffbff, 0xfefefeff, 0xfdf7efbf,
  48             0xfbdf7bdf, 0xf7bbddef, 0xeeeeeeef, 0xeeddbb77, 0xedb76db7,
  49             0xdb6db6db, 0xdb5b5b5b, 0xdab5ad6b, 0xd5ab55ab, 0xd555aaab,
  50             0xaaaaaaab, 0xaaaa5555, 0xaa952a55, 0xa94a5295, 0xa5252525,
  51             0xa4924925, 0x92491249, 0x91224489, 0x91111111, 0x90884211,
  52             0x88410821, 0x88102041, 0x81010101, 0x80800801, 0x80010001,
  53             0x80000001, 0x00000001, 0x00000000
  54 };
  55
  56 typedef struct _OVRL_SRC_DEST {
  57         /*clipped on-screen pixel position of overlay */
  58         u32 ulDstX1;
  59         u32 ulDstY1;
  60         u32 ulDstX2;
  61         u32 ulDstY2;
  62
  63         /*clipped pixel pos of source data within buffer thses need to be 128 bit word aligned */
  64         u32 ulSrcX1;
  65         u32 ulSrcY1;
  66         u32 ulSrcX2;
  67         u32 ulSrcY2;
  68
  69         /* on-screen pixel position of overlay */
  70         s32 lDstX1;
  71         s32 lDstY1;
  72         s32 lDstX2;
  73         s32 lDstY2;
  74 } OVRL_SRC_DEST;
  75
  76 static u32 ovlWidth, ovlHeight, ovlStride;
  77 static int ovlLinear;
  78
  79 void ResetOverlayRegisters(volatile STG4000REG __iomem *pSTGReg)
  80 {
  81         u32 tmp;
  82
  83         /* Set Overlay address to default */
  84         tmp = STG_READ_REG(DACOverlayAddr);
  85         CLEAR_BITS_FRM_TO(0, 20);
  86         CLEAR_BIT(31);
  87         STG_WRITE_REG(DACOverlayAddr, tmp);
  88
  89         /* Set Overlay U address */
  90         tmp = STG_READ_REG(DACOverlayUAddr);
  91         CLEAR_BITS_FRM_TO(0, 20);
  92         STG_WRITE_REG(DACOverlayUAddr, tmp);
  93
  94         /* Set Overlay V address */
  95         tmp = STG_READ_REG(DACOverlayVAddr);
  96         CLEAR_BITS_FRM_TO(0, 20);
  97         STG_WRITE_REG(DACOverlayVAddr, tmp);
  98
  99         /* Set Overlay Size */
 100         tmp = STG_READ_REG(DACOverlaySize);
 101         CLEAR_BITS_FRM_TO(0, 10);
 102         CLEAR_BITS_FRM_TO(12, 31);
 103         STG_WRITE_REG(DACOverlaySize, tmp);
 104
 105         /* Set Overlay Vt Decimation */
 106         tmp = STG4000_NO_DECIMATION;
 107         STG_WRITE_REG(DACOverlayVtDec, tmp);
 108
 109         /* Set Overlay format to default value */
 110         tmp = STG_READ_REG(DACPixelFormat);
 111         CLEAR_BITS_FRM_TO(4, 7);
 112         CLEAR_BITS_FRM_TO(16, 22);
 113         STG_WRITE_REG(DACPixelFormat, tmp);
 114
 115         /* Set Vertical scaling to default */
 116         tmp = STG_READ_REG(DACVerticalScal);
 117         CLEAR_BITS_FRM_TO(0, 11);
 118         CLEAR_BITS_FRM_TO(16, 22);
 119         tmp |= STG4000_NO_SCALING;      /* Set to no scaling */
 120         STG_WRITE_REG(DACVerticalScal, tmp);
 121
 122         /* Set Horizontal Scaling to default */
 123         tmp = STG_READ_REG(DACHorizontalScal);
 124         CLEAR_BITS_FRM_TO(0, 11);
 125         CLEAR_BITS_FRM_TO(16, 17);
 126         tmp |= STG4000_NO_SCALING;      /* Set to no scaling */
 127         STG_WRITE_REG(DACHorizontalScal, tmp);
 128
 129         /* Set Blend mode to Alpha Blend */
 130         /* ????? SG 08/11/2001 Surely this isn't the alpha blend mode,
 131            hopefully its overwrite
 132          */
 133         tmp = STG_READ_REG(DACBlendCtrl);
 134         CLEAR_BITS_FRM_TO(0, 30);
 135         tmp = (GRAPHICS_MODE << 28);
 136         STG_WRITE_REG(DACBlendCtrl, tmp);
 137
 138 }
 139
 140 int CreateOverlaySurface(volatile STG4000REG __iomem *pSTGReg,
 141                          u32 inWidth,
 142                          u32 inHeight,
 143                          int bLinear,
 144                          u32 ulOverlayOffset,
 145                          u32 * retStride, u32 * retUVStride)
 146 {
 147         u32 tmp;
 148         u32 ulStride;
 149
 150         if (inWidth > STG4000_OVRL_MAX_WIDTH ||
 151             inHeight > STG4000_OVRL_MAX_HEIGHT) {
 152                 return -EINVAL;
 153         }
 154
 155         /* Stride in 16 byte words - 16Bpp */
 156         if (bLinear) {
 157                 /* Format is 16bits so num 16 byte words is width/8 */
 158                 if ((inWidth & 0x7) == 0) {     /* inWidth % 8 */
 159                         ulStride = (inWidth / 8);
 160                 } else {
 161                         /* Round up to next 16byte boundary */
 162                         ulStride = ((inWidth + 8) / 8);
 163                 }
 164         } else {
 165                 /* Y component is 8bits so num 16 byte words is width/16 */
 166                 if ((inWidth & 0xf) == 0) {     /* inWidth % 16 */
 167                         ulStride = (inWidth / 16);
 168                 } else {
 169                         /* Round up to next 16byte boundary */
 170                         ulStride = ((inWidth + 16) / 16);
 171                 }
 172         }
 173
 174
 175         /* Set Overlay address and Format mode */
 176         tmp = STG_READ_REG(DACOverlayAddr);
 177         CLEAR_BITS_FRM_TO(0, 20);
 178         if (bLinear) {
 179                 CLEAR_BIT(31);  /* Overlay format to Linear */
 180         } else {
 181                 tmp |= SET_BIT(31);     /* Overlay format to Planer */
 182         }
 183
 184         /* Only bits 24:4 of the Overlay address */
 185         tmp |= (ulOverlayOffset >> 4);
 186         STG_WRITE_REG(DACOverlayAddr, tmp);
 187
 188         if (!bLinear) {
 189                 u32 uvSize =
 190                     (inWidth & 0x1) ? (inWidth + 1 / 2) : (inWidth / 2);
 191                 u32 uvStride;
 192                 u32 ulOffset;
 193                 /* Y component is 8bits so num 32 byte words is width/32 */
 194                 if ((uvSize & 0xf) == 0) {      /* inWidth % 16 */
 195                         uvStride = (uvSize / 16);
 196                 } else {
 197                         /* Round up to next 32byte boundary */
 198                         uvStride = ((uvSize + 16) / 16);
 199                 }
 200
 201                 ulOffset = ulOverlayOffset + (inHeight * (ulStride * 16));
 202                 /* Align U,V data to 32byte boundary */
 203                 if ((ulOffset & 0x1f) != 0)
 204                         ulOffset = (ulOffset + 32L) & 0xffffffE0L;
 205
 206                 tmp = STG_READ_REG(DACOverlayUAddr);
 207                 CLEAR_BITS_FRM_TO(0, 20);
 208                 tmp |= (ulOffset >> 4);
 209                 STG_WRITE_REG(DACOverlayUAddr, tmp);
 210
 211                 ulOffset += (inHeight / 2) * (uvStride * 16);
 212                 /* Align U,V data to 32byte boundary */
 213                 if ((ulOffset & 0x1f) != 0)
 214                         ulOffset = (ulOffset + 32L) & 0xffffffE0L;
 215
 216                 tmp = STG_READ_REG(DACOverlayVAddr);
 217                 CLEAR_BITS_FRM_TO(0, 20);
 218                 tmp |= (ulOffset >> 4);
 219                 STG_WRITE_REG(DACOverlayVAddr, tmp);
 220
 221                 *retUVStride = uvStride * 16;
 222         }
 223
 224
 225         /* Set Overlay YUV pixel format
 226          * Make sure that LUT not used - ??????
 227          */
 228         tmp = STG_READ_REG(DACPixelFormat);
 229         /* Only support Planer or UYVY linear formats */
 230         CLEAR_BITS_FRM_TO(4, 9);
 231         STG_WRITE_REG(DACPixelFormat, tmp);
 232
 233         ovlWidth = inWidth;
 234         ovlHeight = inHeight;
 235         ovlStride = ulStride;
 236         ovlLinear = bLinear;
 237         *retStride = ulStride << 4;     /* In bytes */
 238
 239         return 0;
 240 }
 241
 242 int SetOverlayBlendMode(volatile STG4000REG __iomem *pSTGReg,
 243                         OVRL_BLEND_MODE mode,
 244                         u32 ulAlpha, u32 ulColorKey)
 245 {
 246         u32 tmp;
 247
 248         tmp = STG_READ_REG(DACBlendCtrl);
 249         CLEAR_BITS_FRM_TO(28, 30);
 250         tmp |= (mode << 28);
 251
 252         switch (mode) {
 253         case COLOR_KEY:
 254                 CLEAR_BITS_FRM_TO(0, 23);
 255                 tmp |= (ulColorKey & 0x00FFFFFF);
 256                 break;
 257
 258         case GLOBAL_ALPHA:
 259                 CLEAR_BITS_FRM_TO(24, 27);
 260                 tmp |= ((ulAlpha & 0xF) << 24);
 261                 break;
 262
 263         case CK_PIXEL_ALPHA:
 264                 CLEAR_BITS_FRM_TO(0, 23);
 265                 tmp |= (ulColorKey & 0x00FFFFFF);
 266                 break;
 267
 268         case CK_GLOBAL_ALPHA:
 269                 CLEAR_BITS_FRM_TO(0, 23);
 270                 tmp |= (ulColorKey & 0x00FFFFFF);
 271                 CLEAR_BITS_FRM_TO(24, 27);
 272                 tmp |= ((ulAlpha & 0xF) << 24);
 273                 break;
 274
 275         case GRAPHICS_MODE:
 276         case PER_PIXEL_ALPHA:
 277                 break;
 278
 279         default:
 280                 return -EINVAL;
 281         }
 282
 283         STG_WRITE_REG(DACBlendCtrl, tmp);
 284
 285         return 0;
 286 }
 287
 288 void EnableOverlayPlane(volatile STG4000REG __iomem *pSTGReg)
 289 {
 290         u32 tmp;
 291         /* Enable Overlay */
 292         tmp = STG_READ_REG(DACPixelFormat);
 293         tmp |= SET_BIT(7);
 294         STG_WRITE_REG(DACPixelFormat, tmp);
 295
 296         /* Set video stream control */
 297         tmp = STG_READ_REG(DACStreamCtrl);
 298         tmp |= SET_BIT(1);      /* video stream */
 299         STG_WRITE_REG(DACStreamCtrl, tmp);
 300 }
 301
 302 static u32 Overlap(u32 ulBits, u32 ulPattern)
 303 {
 304         u32 ulCount = 0;
 305
 306         while (ulBits) {
 307                 if (!(ulPattern & 1))
 308                         ulCount++;
 309                 ulBits--;
 310                 ulPattern = ulPattern >> 1;
 311         }
 312
 313         return ulCount;
 314
 315 }
 316
 317 int SetOverlayViewPort(volatile STG4000REG __iomem *pSTGReg,
 318                        u32 left, u32 top,
 319                        u32 right, u32 bottom)
 320 {
 321         OVRL_SRC_DEST srcDest;
 322
 323         u32 ulSrcTop, ulSrcBottom;
 324         u32 ulSrc, ulDest;
 325         u32 ulFxScale, ulFxOffset;
 326         u32 ulHeight, ulWidth;
 327         u32 ulPattern;
 328         u32 ulDecimate, ulDecimated;
 329         u32 ulApplied;
 330         u32 ulDacXScale, ulDacYScale;
 331         u32 ulScale;
 332         u32 ulLeft, ulRight;
 333         u32 ulSrcLeft, ulSrcRight;
 334         u32 ulScaleLeft, ulScaleRight;
 335         u32 ulhDecim;
 336         u32 ulsVal;
 337         u32 ulVertDecFactor;
 338         int bResult;
 339         u32 ulClipOff = 0;
 340         u32 ulBits = 0;
 341         u32 ulsAdd = 0;
 342         u32 tmp, ulStride;
 343         u32 ulExcessPixels, ulClip, ulExtraLines;
 344
 345
 346         srcDest.ulSrcX1 = 0;
 347         srcDest.ulSrcY1 = 0;
 348         srcDest.ulSrcX2 = ovlWidth - 1;
 349         srcDest.ulSrcY2 = ovlHeight - 1;
 350
 351         srcDest.ulDstX1 = left;
 352         srcDest.ulDstY1 = top;
 353         srcDest.ulDstX2 = right;
 354         srcDest.ulDstY2 = bottom;
 355
 356         srcDest.lDstX1 = srcDest.ulDstX1;
 357         srcDest.lDstY1 = srcDest.ulDstY1;
 358         srcDest.lDstX2 = srcDest.ulDstX2;
 359         srcDest.lDstY2 = srcDest.ulDstY2;
 360
 361     /************* Vertical decimation/scaling ******************/
 362
 363         /* Get Src Top and Bottom */
 364         ulSrcTop = srcDest.ulSrcY1;
 365         ulSrcBottom = srcDest.ulSrcY2;
 366
 367         ulSrc = ulSrcBottom - ulSrcTop;
 368         ulDest = srcDest.lDstY2 - srcDest.lDstY1;       /* on-screen overlay */
 369
 370         if (ulSrc <= 1)
 371                 return -EINVAL;
 372
 373         /* First work out the position we are to display as offset from the
 374          * source of the buffer
 375          */
 376         ulFxScale = (ulDest << 11) / ulSrc;     /* fixed point scale factor */
 377         ulFxOffset = (srcDest.lDstY2 - srcDest.ulDstY2) << 11;
 378
 379         ulSrcBottom = ulSrcBottom - (ulFxOffset / ulFxScale);
 380         ulSrc = ulSrcBottom - ulSrcTop;
 381         ulHeight = ulSrc;
 382
 383         ulDest = srcDest.ulDstY2 - (srcDest.ulDstY1 - 1);
 384         ulPattern = adwDecim8[ulBits];
 385
 386         /* At this point ulSrc represents the input decimator */
 387         if (ulSrc > ulDest) {
 388                 ulDecimate = ulSrc - ulDest;
 389                 ulBits = 0;
 390                 ulApplied = ulSrc / 32;
 391
 392                 while (((ulBits * ulApplied) +
 393                         Overlap((ulSrc % 32),
 394                                 adwDecim8[ulBits])) < ulDecimate)
 395                         ulBits++;
 396
 397                 ulPattern = adwDecim8[ulBits];
 398                 ulDecimated =
 399                     (ulBits * ulApplied) + Overlap((ulSrc % 32),
 400                                                    ulPattern);
 401                 ulSrc = ulSrc - ulDecimated;    /* the number number of lines that will go into the scaler */
 402         }
 403
 404         if (ulBits && (ulBits != 32)) {
 405                 ulVertDecFactor = (63 - ulBits) / (32 - ulBits);        /* vertical decimation factor scaled up to nearest integer */
 406         } else {
 407                 ulVertDecFactor = 1;
 408         }
 409
 410         ulDacYScale = ((ulSrc - 1) * 2048) / (ulDest + 1);
 411
 412         tmp = STG_READ_REG(DACOverlayVtDec);    /* Decimation */
 413         CLEAR_BITS_FRM_TO(0, 31);
 414         tmp = ulPattern;
 415         STG_WRITE_REG(DACOverlayVtDec, tmp);
 416
 417         /***************** Horizontal decimation/scaling ***************************/
 418
 419         /*
 420          * Now we handle the horizontal case, this is a simplified verison of
 421          * the vertical case in that we decimate by factors of 2.  as we are
 422          * working in words we should always be able to decimate by these
 423          * factors.  as we always have to have a buffer which is aligned to a
 424          * whole number of 128 bit words, we must align the left side to the
 425          * lowest to the next lowest 128 bit boundary, and the right hand edge
 426          * to the next largets boundary, (in a similar way to how we didi it in
 427          * PMX1) as the left and right hand edges are aligned to these
 428          * boundaries normally this only becomes an issue when we are chopping
 429          * of one of the sides We shall work out vertical stuff first
 430          */
 431         ulSrc = srcDest.ulSrcX2 - srcDest.ulSrcX1;
 432         ulDest = srcDest.lDstX2 - srcDest.lDstX1;
 433 #ifdef _OLDCODE
 434         ulLeft = srcDest.ulDstX1;
 435         ulRight = srcDest.ulDstX2;
 436 #else
 437         if (srcDest.ulDstX1 > 2) {
 438                 ulLeft = srcDest.ulDstX1 + 2;
 439                 ulRight = srcDest.ulDstX2 + 1;
 440         } else {
 441                 ulLeft = srcDest.ulDstX1;
 442                 ulRight = srcDest.ulDstX2 + 1;
 443         }
 444 #endif
 445         /* first work out the position we are to display as offset from the source of the buffer */
 446         bResult = 1;
 447
 448         do {
 449                 if (ulDest == 0)
 450                         return -EINVAL;
 451
 452                 /* source pixels per dest pixel <<11 */
 453                 ulFxScale = ((ulSrc - 1) << 11) / (ulDest);
 454
 455                 /* then number of destination pixels out we are */
 456                 ulFxOffset = ulFxScale * ((srcDest.ulDstX1 - srcDest.lDstX1) + ulClipOff);
 457                 ulFxOffset >>= 11;
 458
 459                 /* this replaces the code which was making a decision as to use either ulFxOffset or ulSrcX1 */
 460                 ulSrcLeft = srcDest.ulSrcX1 + ulFxOffset;
 461
 462                 /* then number of destination pixels out we are */
 463                 ulFxOffset = ulFxScale * (srcDest.lDstX2 - srcDest.ulDstX2);
 464                 ulFxOffset >>= 11;
 465
 466                 ulSrcRight = srcDest.ulSrcX2 - ulFxOffset;
 467
 468                 /*
 469                  * we must align these to our 128 bit boundaries. we shall
 470                  * round down the pixel pos to the nearest 8 pixels.
 471                  */
 472                 ulScaleLeft = ulSrcLeft;
 473                 ulScaleRight = ulSrcRight;
 474
 475                 /* shift fxscale until it is in the range of the scaler */
 476                 ulhDecim = 0;
 477                 ulScale = (((ulSrcRight - ulSrcLeft) - 1) << (11 - ulhDecim)) / (ulRight - ulLeft + 2);
 478
 479                 while (ulScale > 0x800) {
 480                         ulhDecim++;
 481                         ulScale = (((ulSrcRight - ulSrcLeft) - 1) << (11 - ulhDecim)) / (ulRight - ulLeft + 2);
 482                 }
 483
 484                 /*
 485                  * to try and get the best values We first try and use
 486                  * src/dwdest for the scale factor, then we move onto src-1
 487                  *
 488                  * we want to check to see if we will need to clip data, if so
 489                  * then we should clip our source so that we don't need to
 490                  */
 491                 if (!ovlLinear) {
 492                         ulSrcLeft &= ~0x1f;
 493
 494                         /*
 495                          * we must align the right hand edge to the next 32
 496                          * pixel` boundary, must be on a 256 boundary so u, and
 497                          * v are 128 bit aligned
 498                          */
 499                         ulSrcRight = (ulSrcRight + 0x1f) & ~0x1f;
 500                 } else {
 501                         ulSrcLeft &= ~0x7;
 502
 503                         /*
 504                          * we must align the right hand edge to the next
 505                          * 8pixel` boundary
 506                          */
 507                         ulSrcRight = (ulSrcRight + 0x7) & ~0x7;
 508                 }
 509
 510                 /* this is the input size line store needs to cope with */
 511                 ulWidth = ulSrcRight - ulSrcLeft;
 512
 513                 /*
 514                  * use unclipped value to work out scale factror this is the
 515                  * scale factor we want we shall now work out the horizonal
 516                  * decimation and scaling
 517                  */
 518                 ulsVal = ((ulWidth / 8) >> ulhDecim);
 519
 520                 if ((ulWidth != (ulsVal << ulhDecim) * 8))
 521                         ulsAdd = 1;
 522
 523                 /* input pixels to scaler; */
 524                 ulSrc = ulWidth >> ulhDecim;
 525
 526                 if (ulSrc <= 2)
 527                         return -EINVAL;
 528
 529                 ulExcessPixels = ((((ulScaleLeft - ulSrcLeft)) << (11 - ulhDecim)) / ulScale);
 530
 531                 ulClip = (ulSrc << 11) / ulScale;
 532                 ulClip -= (ulRight - ulLeft);
 533                 ulClip += ulExcessPixels;
 534
 535                 if (ulClip)
 536                         ulClip--;
 537
 538                 /* We may need to do more here if we really have a HW rev < 5 */
 539         } while (!bResult);
 540
 541         ulExtraLines = (1 << ulhDecim) * ulVertDecFactor;
 542         ulExtraLines += 64;
 543         ulHeight += ulExtraLines;
 544
 545         ulDacXScale = ulScale;
 546
 547
 548         tmp = STG_READ_REG(DACVerticalScal);
 549         CLEAR_BITS_FRM_TO(0, 11);
 550         CLEAR_BITS_FRM_TO(16, 22);      /* Vertical Scaling */
 551
 552         /* Calculate new output line stride, this is always the number of 422
 553            words in the line buffer, so it doesn't matter if the
 554            mode is 420. Then set the vertical scale register.
 555          */
 556         ulStride = (ulWidth >> (ulhDecim + 3)) + ulsAdd;
 557         tmp |= ((ulStride << 16) | (ulDacYScale));      /* DAC_LS_CTRL = stride */
 558         STG_WRITE_REG(DACVerticalScal, tmp);
 559
 560         /* Now set up the overlay size using the modified width and height
 561            from decimate and scaling calculations
 562          */
 563         tmp = STG_READ_REG(DACOverlaySize);
 564         CLEAR_BITS_FRM_TO(0, 10);
 565         CLEAR_BITS_FRM_TO(12, 31);
 566
 567         if (ovlLinear) {
 568                 tmp |=
 569                     (ovlStride | ((ulHeight + 1) << 12) |
 570                      (((ulWidth / 8) - 1) << 23));
 571         } else {
 572                 tmp |=
 573                     (ovlStride | ((ulHeight + 1) << 12) |
 574                      (((ulWidth / 32) - 1) << 23));
 575         }
 576
 577         STG_WRITE_REG(DACOverlaySize, tmp);
 578
 579         /* Set Video Window Start */
 580         tmp = ((ulLeft << 16)) | (srcDest.ulDstY1);
 581         STG_WRITE_REG(DACVidWinStart, tmp);
 582
 583         /* Set Video Window End */
 584         tmp = ((ulRight) << 16) | (srcDest.ulDstY2);
 585         STG_WRITE_REG(DACVidWinEnd, tmp);
 586
 587         /* Finally set up the rest of the overlay regs in the order
 588            done in the IMG driver
 589          */
 590         tmp = STG_READ_REG(DACPixelFormat);
 591         tmp = ((ulExcessPixels << 16) | tmp) & 0x7fffffff;
 592         STG_WRITE_REG(DACPixelFormat, tmp);
 593
 594         tmp = STG_READ_REG(DACHorizontalScal);
 595         CLEAR_BITS_FRM_TO(0, 11);
 596         CLEAR_BITS_FRM_TO(16, 17);
 597         tmp |= ((ulhDecim << 16) | (ulDacXScale));
 598         STG_WRITE_REG(DACHorizontalScal, tmp);
 599
 600         return 0;
 601 }