sstfb.c 43.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533
/*
 * linux/drivers/video/sstfb.c -- voodoo graphics frame buffer
 *
 *     Copyright (c) 2000-2002 Ghozlane Toumi <gtoumi@laposte.net>
 *
 *     Created 15 Jan 2000 by Ghozlane Toumi
 *
 * Contributions (and many thanks) :
 *
 * 03/2001 James Simmons   <jsimmons@infradead.org>
 * 04/2001 Paul Mundt      <lethal@chaoticdreams.org>
 * 05/2001 Urs Ganse       <ursg@uni.de>
 *	(initial work on voodoo2 port, interlace)
 * 09/2002 Helge Deller    <deller@gmx.de>
 *	(enable driver on big-endian machines (hppa), ioctl fixes)
 * 12/2002 Helge Deller    <deller@gmx.de>
 *	(port driver to new frambuffer infrastructure)
 * 01/2003 Helge Deller    <deller@gmx.de>
 *	(initial work on fb hardware acceleration for voodoo2)
 * 08/2006 Alan Cox 	   <alan@redhat.com>
 *	Remove never finished and bogus 24/32bit support
 *	Clean up macro abuse
 *	Minor tidying for format.
 * 12/2006 Helge Deller    <deller@gmx.de>
 *	add /sys/class/graphics/fbX/vgapass sysfs-interface
 *	add module option "mode_option" to set initial screen mode
 *	use fbdev default videomode database
 *	remove debug functions from ioctl
 */

/*
 * The voodoo1 has the following memory mapped address space:
 * 0x000000 - 0x3fffff : registers              (4MB)
 * 0x400000 - 0x7fffff : linear frame buffer    (4MB)
 * 0x800000 - 0xffffff : texture memory         (8MB)
 */

/*
 * misc notes, TODOs, toASKs, and deep thoughts

-TODO: at one time or another test that the mode is acceptable by the monitor
-ASK: Can I choose different ordering for the color bitfields (rgba argb ...)
      which one should i use ? is there any preferred one ? It seems ARGB is
      the one ...
-TODO: in  set_var check the validity of timings (hsync vsync)...
-TODO: check and recheck the use of sst_wait_idle : we don't flush the fifo via
       a nop command. so it's ok as long as the commands we pass don't go
       through the fifo. warning: issuing a nop command seems to need pci_fifo
-FIXME: in case of failure in the init sequence, be sure we return to a safe
        state.
- FIXME: Use accelerator for 2D scroll
-FIXME: 4MB boards have banked memory (FbiInit2 bits 1 & 20)
 */

/*
 * debug info
 * SST_DEBUG : enable debugging
 * SST_DEBUG_REG : debug registers
 *   0 :  no debug
 *   1 : dac calls, [un]set_bits, FbiInit
 *   2 : insane debug level (log every register read/write)
 * SST_DEBUG_FUNC : functions
 *   0 : no debug
 *   1 : function call / debug ioctl
 *   2 : variables
 *   3 : flood . you don't want to do that. trust me.
 * SST_DEBUG_VAR : debug display/var structs
 *   0 : no debug
 *   1 : dumps display, fb_var
 *
 * sstfb specific ioctls:
 *   		toggle vga (0x46db) : toggle vga_pass_through
 */

#undef SST_DEBUG


/*
 * Includes
 */

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fb.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <asm/io.h>
#include <linux/uaccess.h>
#include <video/sstfb.h>


/* initialized by setup */

static bool vgapass;		/* enable VGA passthrough cable */
static int mem;			/* mem size in MB, 0 = autodetect */
static bool clipping = 1;	/* use clipping (slower, safer) */
static int gfxclk;		/* force FBI freq in Mhz . Dangerous */
static bool slowpci;		/* slow PCI settings */

/*
  Possible default video modes: 800x600@60, 640x480@75, 1024x768@76, 640x480@60
*/
#define DEFAULT_VIDEO_MODE "640x480@60"

static char *mode_option __devinitdata = DEFAULT_VIDEO_MODE;

enum {
	ID_VOODOO1 = 0,
	ID_VOODOO2 = 1,
};

#define IS_VOODOO2(par) ((par)->type == ID_VOODOO2)

static struct sst_spec voodoo_spec[] __devinitdata = {
 { .name = "Voodoo Graphics", .default_gfx_clock = 50000, .max_gfxclk = 60 },
 { .name = "Voodoo2",	      .default_gfx_clock = 75000, .max_gfxclk = 85 },
};


/*
 * debug functions
 */

#if (SST_DEBUG_REG > 0)
static void sst_dbg_print_read_reg(u32 reg, u32 val) {
	const char *regname;
	switch (reg) {
	case FBIINIT0:	regname = "FbiInit0"; break;
	case FBIINIT1:	regname = "FbiInit1"; break;
	case FBIINIT2:	regname = "FbiInit2"; break;
	case FBIINIT3:	regname = "FbiInit3"; break;
	case FBIINIT4:	regname = "FbiInit4"; break;
	case FBIINIT5:	regname = "FbiInit5"; break;
	case FBIINIT6:	regname = "FbiInit6"; break;
	default:	regname = NULL;       break;
	}
	if (regname == NULL)
		r_ddprintk("sst_read(%#x): %#x\n", reg, val);
	else
		r_dprintk(" sst_read(%s): %#x\n", regname, val);
}

static void sst_dbg_print_write_reg(u32 reg, u32 val) {
	const char *regname;
	switch (reg) {
	case FBIINIT0:	regname = "FbiInit0"; break;
	case FBIINIT1:	regname = "FbiInit1"; break;
	case FBIINIT2:	regname = "FbiInit2"; break;
	case FBIINIT3:	regname = "FbiInit3"; break;
	case FBIINIT4:	regname = "FbiInit4"; break;
	case FBIINIT5:	regname = "FbiInit5"; break;
	case FBIINIT6:	regname = "FbiInit6"; break;
	default:	regname = NULL;       break;
	}
	if (regname == NULL)
		r_ddprintk("sst_write(%#x, %#x)\n", reg, val);
	else
		r_dprintk(" sst_write(%s, %#x)\n", regname, val);
}
#else /*  (SST_DEBUG_REG > 0) */
#  define sst_dbg_print_read_reg(reg, val)	do {} while(0)
#  define sst_dbg_print_write_reg(reg, val)	do {} while(0)
#endif /*  (SST_DEBUG_REG > 0) */

/*
 * hardware access functions
 */

/* register access */
#define sst_read(reg)		__sst_read(par->mmio_vbase, reg)
#define sst_write(reg,val)	__sst_write(par->mmio_vbase, reg, val)
#define sst_set_bits(reg,val)	__sst_set_bits(par->mmio_vbase, reg, val)
#define sst_unset_bits(reg,val)	__sst_unset_bits(par->mmio_vbase, reg, val)
#define sst_dac_read(reg)	__sst_dac_read(par->mmio_vbase, reg)
#define sst_dac_write(reg,val)	__sst_dac_write(par->mmio_vbase, reg, val)
#define dac_i_read(reg)		__dac_i_read(par->mmio_vbase, reg)
#define dac_i_write(reg,val)	__dac_i_write(par->mmio_vbase, reg, val)

static inline u32 __sst_read(u8 __iomem *vbase, u32 reg)
{
	u32 ret = readl(vbase + reg);
	sst_dbg_print_read_reg(reg, ret);
	return ret;
}

static inline void __sst_write(u8 __iomem *vbase, u32 reg, u32 val)
{
	sst_dbg_print_write_reg(reg, val);
	writel(val, vbase + reg);
}

static inline void __sst_set_bits(u8 __iomem *vbase, u32 reg, u32 val)
{
	r_dprintk("sst_set_bits(%#x, %#x)\n", reg, val);
	__sst_write(vbase, reg, __sst_read(vbase, reg) | val);
}

static inline void __sst_unset_bits(u8 __iomem *vbase, u32 reg, u32 val)
{
	r_dprintk("sst_unset_bits(%#x, %#x)\n", reg, val);
	__sst_write(vbase, reg, __sst_read(vbase, reg) & ~val);
}

/*
 * wait for the fbi chip. ASK: what happens if the fbi is stuck ?
 *
 * the FBI is supposed to be ready if we receive 5 time
 * in a row a "idle" answer to our requests
 */

#define sst_wait_idle() __sst_wait_idle(par->mmio_vbase)

static int __sst_wait_idle(u8 __iomem *vbase)
{
	int count = 0;

	/* if (doFBINOP) __sst_write(vbase, NOPCMD, 0); */

	while(1) {
		if (__sst_read(vbase, STATUS) & STATUS_FBI_BUSY) {
			f_dddprintk("status: busy\n");
/* FIXME basically, this is a busy wait. maybe not that good. oh well;
 * this is a small loop after all.
 * Or maybe we should use mdelay() or udelay() here instead ? */
			count = 0;
		} else {
			count++;
			f_dddprintk("status: idle(%d)\n", count);
		}
		if (count >= 5) return 1;
/* XXX  do something to avoid hanging the machine if the voodoo is out */
	}
}


/* dac access */
/* dac_read should be remaped to FbiInit2 (via the pci reg init_enable) */
static u8 __sst_dac_read(u8 __iomem *vbase, u8 reg)
{
	u8 ret;

	reg &= 0x07;
	__sst_write(vbase, DAC_DATA, ((u32)reg << 8) | DAC_READ_CMD );
	__sst_wait_idle(vbase);
	/* udelay(10); */
	ret = __sst_read(vbase, DAC_READ) & 0xff;
	r_dprintk("sst_dac_read(%#x): %#x\n", reg, ret);

	return ret;
}

static void __sst_dac_write(u8 __iomem *vbase, u8 reg, u8 val)
{
	r_dprintk("sst_dac_write(%#x, %#x)\n", reg, val);
	reg &= 0x07;
	__sst_write(vbase, DAC_DATA,(((u32)reg << 8)) | (u32)val);
	__sst_wait_idle(vbase);
}

/* indexed access to ti/att dacs */
static u32 __dac_i_read(u8 __iomem *vbase, u8 reg)
{
	u32 ret;

	__sst_dac_write(vbase, DACREG_ADDR_I, reg);
	ret = __sst_dac_read(vbase, DACREG_DATA_I);
	r_dprintk("sst_dac_read_i(%#x): %#x\n", reg, ret);
	return ret;
}
static void __dac_i_write(u8 __iomem *vbase, u8 reg,u8 val)
{
	r_dprintk("sst_dac_write_i(%#x, %#x)\n", reg, val);
	__sst_dac_write(vbase, DACREG_ADDR_I, reg);
	__sst_dac_write(vbase, DACREG_DATA_I, val);
}

/* compute the m,n,p  , returns the real freq
 * (ics datasheet :  N <-> N1 , P <-> N2)
 *
 * Fout= Fref * (M+2)/( 2^P * (N+2))
 *  we try to get close to the asked freq
 *  with P as high, and M as low as possible
 * range:
 * ti/att : 0 <= M <= 255; 0 <= P <= 3; 0<= N <= 63
 * ics    : 1 <= M <= 127; 0 <= P <= 3; 1<= N <= 31
 * we'll use the lowest limitation, should be precise enouth
 */
static int sst_calc_pll(const int freq, int *freq_out, struct pll_timing *t)
{
	int m, m2, n, p, best_err, fout;
	int best_n = -1;
	int best_m = -1;

	best_err = freq;
	p = 3;
	/* f * 2^P = vco should be less than VCOmax ~ 250 MHz for ics*/
	while (((1 << p) * freq > VCO_MAX) && (p >= 0))
		p--;
	if (p == -1)
		return -EINVAL;
	for (n = 1; n < 32; n++) {
		/* calc 2 * m so we can round it later*/
		m2 = (2 * freq * (1 << p) * (n + 2) ) / DAC_FREF - 4 ;

		m = (m2 % 2 ) ? m2/2+1 : m2/2 ;
		if (m >= 128)
			break;
		fout = (DAC_FREF * (m + 2)) / ((1 << p) * (n + 2));
		if ((abs(fout - freq) < best_err) && (m > 0)) {
			best_n = n;
			best_m = m;
			best_err = abs(fout - freq);
			/* we get the lowest m , allowing 0.5% error in freq*/
			if (200*best_err < freq) break;
		}
	}
	if (best_n == -1)  /* unlikely, but who knows ? */
		return -EINVAL;
	t->p = p;
	t->n = best_n;
	t->m = best_m;
	*freq_out = (DAC_FREF * (t->m + 2)) / ((1 << t->p) * (t->n + 2));
	f_ddprintk ("m: %d, n: %d, p: %d, F: %dKhz\n",
		  t->m, t->n, t->p, *freq_out);
	return 0;
}

/*
 * clear lfb screen
 */
static void sstfb_clear_screen(struct fb_info *info)
{
	/* clear screen */
	fb_memset(info->screen_base, 0, info->fix.smem_len);
}


/**
 *      sstfb_check_var - Optional function.  Validates a var passed in.
 *      @var: frame buffer variable screen structure
 *      @info: frame buffer structure that represents a single frame buffer
 *
 *	Limit to the abilities of a single chip as SLI is not supported
 *	by this driver.
 */

static int sstfb_check_var(struct fb_var_screeninfo *var,
		struct fb_info *info)
{
	struct sstfb_par *par = info->par;
	int hSyncOff   = var->xres + var->right_margin + var->left_margin;
	int vSyncOff   = var->yres + var->lower_margin + var->upper_margin;
	int vBackPorch = var->left_margin, yDim = var->yres;
	int vSyncOn    = var->vsync_len;
	int tiles_in_X, real_length;
	unsigned int freq;

	if (sst_calc_pll(PICOS2KHZ(var->pixclock), &freq, &par->pll)) {
		printk(KERN_ERR "sstfb: Pixclock at %ld KHZ out of range\n",
				PICOS2KHZ(var->pixclock));
		return -EINVAL;
	}
	var->pixclock = KHZ2PICOS(freq);
	
	if (var->vmode & FB_VMODE_INTERLACED)
		vBackPorch += (vBackPorch % 2);
	if (var->vmode & FB_VMODE_DOUBLE) {
		vBackPorch <<= 1;
		yDim <<=1;
		vSyncOn <<=1;
		vSyncOff <<=1;
	}

	switch (var->bits_per_pixel) {
	case 0 ... 16 :
		var->bits_per_pixel = 16;
		break;
	default :
		printk(KERN_ERR "sstfb: Unsupported bpp %d\n", var->bits_per_pixel);
		return -EINVAL;
	}
	
	/* validity tests */
	if (var->xres <= 1 || yDim <= 0 || var->hsync_len <= 1  ||
	    hSyncOff <= 1  || var->left_margin <= 2  || vSyncOn <= 0 ||
	    vSyncOff <= 0 || vBackPorch <= 0) {
		return -EINVAL;
	}

	if (IS_VOODOO2(par)) {
		/* Voodoo 2 limits */
		tiles_in_X = (var->xres + 63 ) / 64 * 2;		

		if (var->xres  > POW2(11) || yDim >= POW2(11)) {
			printk(KERN_ERR "sstfb: Unsupported resolution %dx%d\n",
			         var->xres, var->yres);
			return -EINVAL;
		}

		if (var->hsync_len > POW2(9) || hSyncOff > POW2(11) ||
		    var->left_margin - 2 >= POW2(9) || vSyncOn >= POW2(13) ||
		    vSyncOff >= POW2(13) || vBackPorch >= POW2(9) ||
		    tiles_in_X >= POW2(6) || tiles_in_X <= 0) {
			printk(KERN_ERR "sstfb: Unsupported timings\n");
			return -EINVAL;
		}
	} else {
		/* Voodoo limits */
		tiles_in_X = (var->xres + 63 ) / 64;

		if (var->vmode) {
			printk(KERN_ERR "sstfb: Interlace/doublescan not supported %#x\n",
				var->vmode);
			return -EINVAL;
		}
		if (var->xres > POW2(10) || var->yres >= POW2(10)) {
			printk(KERN_ERR "sstfb: Unsupported resolution %dx%d\n",
			         var->xres, var->yres);
			return -EINVAL;
		}
		if (var->hsync_len > POW2(8) || hSyncOff - 1 > POW2(10) ||
		    var->left_margin - 2 >= POW2(8) || vSyncOn >= POW2(12) ||
		    vSyncOff >= POW2(12) || vBackPorch >= POW2(8) ||
		    tiles_in_X >= POW2(4) || tiles_in_X <= 0) {
			printk(KERN_ERR "sstfb: Unsupported timings\n");
			return -EINVAL;
		}
	}

	/* it seems that the fbi uses tiles of 64x16 pixels to "map" the mem */
	/* FIXME: i don't like this... looks wrong */
	real_length = tiles_in_X  * (IS_VOODOO2(par) ? 32 : 64 )
	              * ((var->bits_per_pixel == 16) ? 2 : 4);

	if (real_length * yDim > info->fix.smem_len) {
		printk(KERN_ERR "sstfb: Not enough video memory\n");
		return -ENOMEM;
	}

	var->sync &= (FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT);
	var->vmode &= (FB_VMODE_INTERLACED | FB_VMODE_DOUBLE);
	var->xoffset = 0;
	var->yoffset = 0;
	var->height  = -1;
	var->width   = -1;

	/*
	 * correct the color bit fields
	 */
	/* var->{red|green|blue}.msb_right = 0; */

	switch (var->bits_per_pixel) {
	case 16:	/* RGB 565  LfbMode 0 */
		var->red.length    = 5;
		var->green.length  = 6;
		var->blue.length   = 5;
		var->transp.length = 0;

		var->red.offset    = 11;
		var->green.offset  = 5;
		var->blue.offset   = 0;
		var->transp.offset = 0;
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

/**
 *      sstfb_set_par - Optional function.  Alters the hardware state.
 *      @info: frame buffer structure that represents a single frame buffer
 */
static int sstfb_set_par(struct fb_info *info)
{
	struct sstfb_par *par = info->par;
	u32 lfbmode, fbiinit1, fbiinit2, fbiinit3, fbiinit5, fbiinit6=0;
	struct pci_dev *sst_dev = par->dev;
	unsigned int freq;
	int ntiles;

	par->hSyncOff	= info->var.xres + info->var.right_margin + info->var.left_margin;

	par->yDim 	= info->var.yres;
	par->vSyncOn 	= info->var.vsync_len;
	par->vSyncOff	= info->var.yres + info->var.lower_margin + info->var.upper_margin;
	par->vBackPorch = info->var.upper_margin;

	/* We need par->pll */
	sst_calc_pll(PICOS2KHZ(info->var.pixclock), &freq, &par->pll);

	if (info->var.vmode & FB_VMODE_INTERLACED)
		par->vBackPorch += (par->vBackPorch % 2);
	if (info->var.vmode & FB_VMODE_DOUBLE) {
		par->vBackPorch <<= 1;
		par->yDim <<=1;
		par->vSyncOn <<=1;
		par->vSyncOff <<=1;
	}

	if (IS_VOODOO2(par)) {
		/* voodoo2 has 32 pixel wide tiles , BUT strange things
		   happen with odd number of tiles */
		par->tiles_in_X = (info->var.xres + 63 ) / 64 * 2;
	} else {
		/* voodoo1 has 64 pixels wide tiles. */
		par->tiles_in_X = (info->var.xres + 63 ) / 64;
	}

	f_ddprintk("hsync_len hSyncOff vsync_len vSyncOff\n");
	f_ddprintk("%-7d %-8d %-7d %-8d\n",
	           info->var.hsync_len, par->hSyncOff,
	           par->vSyncOn, par->vSyncOff);
	f_ddprintk("left_margin upper_margin xres yres Freq\n");
	f_ddprintk("%-10d %-10d %-4d %-4d %-8ld\n",
	           info->var.left_margin, info->var.upper_margin,
	           info->var.xres, info->var.yres, PICOS2KHZ(info->var.pixclock));

	sst_write(NOPCMD, 0);
	sst_wait_idle();
	pci_write_config_dword(sst_dev, PCI_INIT_ENABLE, PCI_EN_INIT_WR);
	sst_set_bits(FBIINIT1, VIDEO_RESET);
	sst_set_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
	sst_unset_bits(FBIINIT2, EN_DRAM_REFRESH);
	sst_wait_idle();

	/*sst_unset_bits (FBIINIT0, FBI_RESET); / reenable FBI ? */

	sst_write(BACKPORCH, par->vBackPorch << 16 | (info->var.left_margin - 2));
	sst_write(VIDEODIMENSIONS, par->yDim << 16 | (info->var.xres - 1));
	sst_write(HSYNC, (par->hSyncOff - 1) << 16 | (info->var.hsync_len - 1));
	sst_write(VSYNC,       par->vSyncOff << 16 | par->vSyncOn);

	fbiinit2 = sst_read(FBIINIT2);
	fbiinit3 = sst_read(FBIINIT3);

	/* everything is reset. we enable fbiinit2/3 remap : dac access ok */
	pci_write_config_dword(sst_dev, PCI_INIT_ENABLE,
	                       PCI_EN_INIT_WR | PCI_REMAP_DAC );

	par->dac_sw.set_vidmod(info, info->var.bits_per_pixel);

	/* set video clock */
	par->dac_sw.set_pll(info, &par->pll, VID_CLOCK);

	/* disable fbiinit2/3 remap */
	pci_write_config_dword(sst_dev, PCI_INIT_ENABLE,
	                       PCI_EN_INIT_WR);

	/* restore fbiinit2/3 */
	sst_write(FBIINIT2,fbiinit2);
	sst_write(FBIINIT3,fbiinit3);

	fbiinit1 = (sst_read(FBIINIT1) & VIDEO_MASK)
	            | EN_DATA_OE
	            | EN_BLANK_OE
	            | EN_HVSYNC_OE
	            | EN_DCLK_OE
		 /* | (15 << TILES_IN_X_SHIFT) */
	            | SEL_INPUT_VCLK_2X
		 /* | (2 << VCLK_2X_SEL_DEL_SHIFT)
	            | (2 << VCLK_DEL_SHIFT) */;
/* try with vclk_in_delay =0 (bits 29:30) , vclk_out_delay =0 (bits(27:28)
 in (near) future set them accordingly to revision + resolution (cf glide)
 first understand what it stands for :)
 FIXME: there are some artefacts... check for the vclk_in_delay
 lets try with 6ns delay in both vclk_out & in...
 doh... they're still there :\
*/

	ntiles = par->tiles_in_X;
	if (IS_VOODOO2(par)) {
		fbiinit1 |= ((ntiles & 0x20) >> 5) << TILES_IN_X_MSB_SHIFT
		            | ((ntiles & 0x1e) >> 1) << TILES_IN_X_SHIFT;
/* as the only value of importance for us in fbiinit6 is tiles in X (lsb),
   and as reading fbinit 6 will return crap (see FBIINIT6_DEFAULT) we just
   write our value. BTW due to the dac unable to read odd number of tiles, this
   field is always null ... */
		fbiinit6 = (ntiles & 0x1) << TILES_IN_X_LSB_SHIFT;
	}
	else
		fbiinit1 |= ntiles << TILES_IN_X_SHIFT;

	switch (info->var.bits_per_pixel) {
	case 16:
		fbiinit1 |=  SEL_SOURCE_VCLK_2X_SEL;
		break;
	default:
		return -EINVAL;
	}
	sst_write(FBIINIT1, fbiinit1);
	if (IS_VOODOO2(par)) {
		sst_write(FBIINIT6, fbiinit6);
		fbiinit5=sst_read(FBIINIT5) & FBIINIT5_MASK ;
		if (info->var.vmode & FB_VMODE_INTERLACED)
			fbiinit5 |= INTERLACE;
		if (info->var.vmode & FB_VMODE_DOUBLE)
			fbiinit5 |= VDOUBLESCAN;
		if (info->var.sync & FB_SYNC_HOR_HIGH_ACT)
			fbiinit5 |= HSYNC_HIGH;
		if (info->var.sync & FB_SYNC_VERT_HIGH_ACT)
			fbiinit5 |= VSYNC_HIGH;
		sst_write(FBIINIT5, fbiinit5);
	}
	sst_wait_idle();
	sst_unset_bits(FBIINIT1, VIDEO_RESET);
	sst_unset_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
	sst_set_bits(FBIINIT2, EN_DRAM_REFRESH);
	/* disables fbiinit writes */
	pci_write_config_dword(sst_dev, PCI_INIT_ENABLE, PCI_EN_FIFO_WR);

	/* set lfbmode : set mode + front buffer for reads/writes
	   + disable pipeline */
	switch (info->var.bits_per_pixel) {
	case 16:
		lfbmode = LFB_565;
		break;
	default:
		return -EINVAL;
	}

#if defined(__BIG_ENDIAN)
	/* Enable byte-swizzle functionality in hardware.
	 * With this enabled, all our read- and write-accesses to
	 * the voodoo framebuffer can be done in native format, and
	 * the hardware will automatically convert it to little-endian.
	 * - tested on HP-PARISC, Helge Deller <deller@gmx.de> */
	lfbmode |= ( LFB_WORD_SWIZZLE_WR | LFB_BYTE_SWIZZLE_WR |
		     LFB_WORD_SWIZZLE_RD | LFB_BYTE_SWIZZLE_RD );
#endif
	
	if (clipping) {
		sst_write(LFBMODE, lfbmode | EN_PXL_PIPELINE);
	/*
	 * Set "clipping" dimensions. If clipping is disabled and
	 * writes to offscreen areas of the framebuffer are performed,
	 * the "behaviour is undefined" (_very_ undefined) - Urs
	 */
	/* btw, it requires enabling pixel pipeline in LFBMODE .
	   off screen read/writes will just wrap and read/print pixels
	   on screen. Ugly but not that dangerous */
		f_ddprintk("setting clipping dimensions 0..%d, 0..%d\n",
		            info->var.xres - 1, par->yDim - 1);

		sst_write(CLIP_LEFT_RIGHT, info->var.xres);
		sst_write(CLIP_LOWY_HIGHY, par->yDim);
		sst_set_bits(FBZMODE, EN_CLIPPING | EN_RGB_WRITE);
	} else {
		/* no clipping : direct access, no pipeline */
		sst_write(LFBMODE, lfbmode);
	}
	return 0;
}

/**
 *      sstfb_setcolreg - Optional function. Sets a color register.
 *      @regno: hardware colormap register
 *      @red: frame buffer colormap structure
 *      @green: The green value which can be up to 16 bits wide
 *      @blue:  The blue value which can be up to 16 bits wide.
 *      @transp: If supported the alpha value which can be up to 16 bits wide.
 *      @info: frame buffer info structure
 */
static int sstfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                           u_int transp, struct fb_info *info)
{
	struct sstfb_par *par = info->par;
	u32 col;

	f_dddprintk("sstfb_setcolreg\n");
	f_dddprintk("%-2d rgbt: %#x, %#x, %#x, %#x\n",
	            regno, red, green, blue, transp);
	if (regno > 15)
		return 0;

	red    >>= (16 - info->var.red.length);
	green  >>= (16 - info->var.green.length);
	blue   >>= (16 - info->var.blue.length);
	transp >>= (16 - info->var.transp.length);
	col = (red << info->var.red.offset)
	    | (green << info->var.green.offset)
	    | (blue  << info->var.blue.offset)
	    | (transp << info->var.transp.offset);
	
	par->palette[regno] = col;

	return 0;
}

static void sstfb_setvgapass( struct fb_info *info, int enable )
{
	struct sstfb_par *par = info->par;
	struct pci_dev *sst_dev = par->dev;
	u32 fbiinit0, tmp;

	enable = enable ? 1:0;
	if (par->vgapass == enable)
		return;
	par->vgapass = enable;

	pci_read_config_dword(sst_dev, PCI_INIT_ENABLE, &tmp);
	pci_write_config_dword(sst_dev, PCI_INIT_ENABLE,
			       tmp | PCI_EN_INIT_WR );
	fbiinit0 = sst_read (FBIINIT0);
	if (par->vgapass) {
		sst_write(FBIINIT0, fbiinit0 & ~DIS_VGA_PASSTHROUGH);
		printk(KERN_INFO "fb%d: Enabling VGA pass-through\n", info->node );
	} else {
		sst_write(FBIINIT0, fbiinit0 | DIS_VGA_PASSTHROUGH);
		printk(KERN_INFO "fb%d: Disabling VGA pass-through\n", info->node );
	}
	pci_write_config_dword(sst_dev, PCI_INIT_ENABLE, tmp);
}

static ssize_t store_vgapass(struct device *device, struct device_attribute *attr,
			const char *buf, size_t count)
{
	struct fb_info *info = dev_get_drvdata(device);
	char ** last = NULL;
	int val;

	val = simple_strtoul(buf, last, 0);
	sstfb_setvgapass(info, val);

	return count;
}

static ssize_t show_vgapass(struct device *device, struct device_attribute *attr,
			char *buf)
{
	struct fb_info *info = dev_get_drvdata(device);
	struct sstfb_par *par = info->par;
	return snprintf(buf, PAGE_SIZE, "%d\n", par->vgapass);
}

static struct device_attribute device_attrs[] = {
	__ATTR(vgapass, S_IRUGO|S_IWUSR, show_vgapass, store_vgapass)
	};

static int sstfb_ioctl(struct fb_info *info, unsigned int cmd,
			unsigned long arg)
{
	struct sstfb_par *par;
	u32 val;

	switch (cmd) {
	/* set/get VGA pass_through mode */
	case SSTFB_SET_VGAPASS:
		if (copy_from_user(&val, (void __user *)arg, sizeof(val)))
			return -EFAULT;
		sstfb_setvgapass(info, val);
		return 0;
	case SSTFB_GET_VGAPASS:
		par = info->par;
		val = par->vgapass;
		if (copy_to_user((void __user *)arg, &val, sizeof(val)))
			return -EFAULT;
		return 0;
	}

	return -EINVAL;
}


/*
 * Screen-to-Screen BitBlt 2D command (for the bmove fb op.) - Voodoo2 only
 */
#if 0
static void sstfb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
	struct sstfb_par *par = info->par;
	u32 stride = info->fix.line_length;
   
	if (!IS_VOODOO2(par))
		return;

	sst_write(BLTSRCBASEADDR, 0);
	sst_write(BLTDSTBASEADDR, 0);
	sst_write(BLTROP, BLTROP_COPY);
	sst_write(BLTXYSTRIDES, stride | (stride << 16));
	sst_write(BLTSRCXY, area->sx | (area->sy << 16));
	sst_write(BLTDSTXY, area->dx | (area->dy << 16));
	sst_write(BLTSIZE, area->width | (area->height << 16));
	sst_write(BLTCOMMAND, BLT_SCR2SCR_BITBLT | LAUNCH_BITBLT |
		(BLT_16BPP_FMT << 3) /* | BIT(14) */ | BIT(15) );
	sst_wait_idle();
}
#endif


/*
 * FillRect 2D command (solidfill or invert (via ROP_XOR)) - Voodoo2 only
 */
#if 0
static void sstfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect) 
{
	struct sstfb_par *par = info->par;
	u32 stride = info->fix.line_length;

	if (!IS_VOODOO2(par))
		return;
   	
	sst_write(BLTCLIPX, info->var.xres);
	sst_write(BLTCLIPY, info->var.yres);
	
	sst_write(BLTDSTBASEADDR, 0);
	sst_write(BLTCOLOR, rect->color);
	sst_write(BLTROP, rect->rop == ROP_COPY ? BLTROP_COPY : BLTROP_XOR);
	sst_write(BLTXYSTRIDES, stride | (stride << 16));
	sst_write(BLTDSTXY, rect->dx | (rect->dy << 16));
	sst_write(BLTSIZE, rect->width | (rect->height << 16));
	sst_write(BLTCOMMAND, BLT_RECFILL_BITBLT | LAUNCH_BITBLT
		 | (BLT_16BPP_FMT << 3) /* | BIT(14) */ | BIT(15) | BIT(16) );
	sst_wait_idle();
}
#endif



/* 
 * get lfb size 
 */
static int __devinit sst_get_memsize(struct fb_info *info, __u32 *memsize)
{
	u8 __iomem *fbbase_virt = info->screen_base;

	/* force memsize */
	if (mem >= 1  && mem <= 4) {
		*memsize = (mem * 0x100000);
		printk(KERN_INFO "supplied memsize: %#x\n", *memsize);
		return 1;
	}

	writel(0xdeadbeef, fbbase_virt);
	writel(0xdeadbeef, fbbase_virt+0x100000);
	writel(0xdeadbeef, fbbase_virt+0x200000);
	f_ddprintk("0MB: %#x, 1MB: %#x, 2MB: %#x\n",
	           readl(fbbase_virt), readl(fbbase_virt + 0x100000),
	           readl(fbbase_virt + 0x200000));

	writel(0xabcdef01, fbbase_virt);

	f_ddprintk("0MB: %#x, 1MB: %#x, 2MB: %#x\n",
	           readl(fbbase_virt), readl(fbbase_virt + 0x100000),
	           readl(fbbase_virt + 0x200000));

	/* checks for 4mb lfb, then 2, then defaults to 1 */
	if (readl(fbbase_virt + 0x200000) == 0xdeadbeef)
		*memsize = 0x400000;
	else if (readl(fbbase_virt + 0x100000) == 0xdeadbeef)
		*memsize = 0x200000;
	else
		*memsize = 0x100000;
	f_ddprintk("detected memsize: %dMB\n", *memsize >> 20);
	return 1;
}


/* 
 * DAC detection routines 
 */

/* fbi should be idle, and fifo emty and mem disabled */
/* supposed to detect AT&T ATT20C409 and Ti TVP3409 ramdacs */

static int __devinit sst_detect_att(struct fb_info *info)
{
	struct sstfb_par *par = info->par;
	int i, mir, dir;

	for (i = 0; i < 3; i++) {
		sst_dac_write(DACREG_WMA, 0); 	/* backdoor */
		sst_dac_read(DACREG_RMR);	/* read 4 times RMR */
		sst_dac_read(DACREG_RMR);
		sst_dac_read(DACREG_RMR);
		sst_dac_read(DACREG_RMR);
		/* the fifth time,  CR0 is read */
		sst_dac_read(DACREG_RMR);
		/* the 6th, manufacturer id register */
		mir = sst_dac_read(DACREG_RMR);
		/*the 7th, device ID register */
		dir = sst_dac_read(DACREG_RMR);
		f_ddprintk("mir: %#x, dir: %#x\n", mir, dir);
		if (mir == DACREG_MIR_ATT && dir == DACREG_DIR_ATT) {
			return 1;
		}
	}
	return 0;
}

static int __devinit sst_detect_ti(struct fb_info *info)
{
	struct sstfb_par *par = info->par;
	int i, mir, dir;

	for (i = 0; i<3; i++) {
		sst_dac_write(DACREG_WMA, 0); 	/* backdoor */
		sst_dac_read(DACREG_RMR);	/* read 4 times RMR */
		sst_dac_read(DACREG_RMR);
		sst_dac_read(DACREG_RMR);
		sst_dac_read(DACREG_RMR);
		/* the fifth time,  CR0 is read */
		sst_dac_read(DACREG_RMR);
		/* the 6th, manufacturer id register */
		mir = sst_dac_read(DACREG_RMR);
		/*the 7th, device ID register */
		dir = sst_dac_read(DACREG_RMR);
		f_ddprintk("mir: %#x, dir: %#x\n", mir, dir);
		if ((mir == DACREG_MIR_TI ) && (dir == DACREG_DIR_TI)) {
			return 1;
		}
	}
	return 0;
}

/*
 * try to detect ICS5342  ramdac
 * we get the 1st byte (M value) of preset f1,f7 and fB
 * why those 3 ? mmmh... for now, i'll do it the glide way...
 * and ask questions later. anyway, it seems that all the freq registers are
 * really at their default state (cf specs) so i ask again, why those 3 regs ?
 * mmmmh.. it seems that's much more ugly than i thought. we use f0 and fA for
 * pll programming, so in fact, we *hope* that the f1, f7 & fB won't be
 * touched...
 * is it really safe ? how can i reset this ramdac ? geee...
 */
static int __devinit sst_detect_ics(struct fb_info *info)
{
	struct sstfb_par *par = info->par;
	int m_clk0_1, m_clk0_7, m_clk1_b;
	int n_clk0_1, n_clk0_7, n_clk1_b;
	int i;

	for (i = 0; i<5; i++ ) {
		sst_dac_write(DACREG_ICS_PLLRMA, 0x1);	/* f1 */
		m_clk0_1 = sst_dac_read(DACREG_ICS_PLLDATA);
		n_clk0_1 = sst_dac_read(DACREG_ICS_PLLDATA);
		sst_dac_write(DACREG_ICS_PLLRMA, 0x7);	/* f7 */
		m_clk0_7 = sst_dac_read(DACREG_ICS_PLLDATA);
		n_clk0_7 = sst_dac_read(DACREG_ICS_PLLDATA);
		sst_dac_write(DACREG_ICS_PLLRMA, 0xb);	/* fB */
		m_clk1_b= sst_dac_read(DACREG_ICS_PLLDATA);
		n_clk1_b= sst_dac_read(DACREG_ICS_PLLDATA);
		f_ddprintk("m_clk0_1: %#x, m_clk0_7: %#x, m_clk1_b: %#x\n",
			m_clk0_1, m_clk0_7, m_clk1_b);
		f_ddprintk("n_clk0_1: %#x, n_clk0_7: %#x, n_clk1_b: %#x\n",
			n_clk0_1, n_clk0_7, n_clk1_b);
		if ((   m_clk0_1 == DACREG_ICS_PLL_CLK0_1_INI)
		    && (m_clk0_7 == DACREG_ICS_PLL_CLK0_7_INI)
		    && (m_clk1_b == DACREG_ICS_PLL_CLK1_B_INI)) {
			return 1;
		}
	}
	return 0;
}


/*
 * gfx, video, pci fifo should be reset, dram refresh disabled
 * see detect_dac
 */

static int sst_set_pll_att_ti(struct fb_info *info, 
		const struct pll_timing *t, const int clock)
{
	struct sstfb_par *par = info->par;
	u8 cr0, cc;

	/* enable indexed mode */
	sst_dac_write(DACREG_WMA, 0); 	/* backdoor */
	sst_dac_read(DACREG_RMR);	/* 1 time:  RMR */
	sst_dac_read(DACREG_RMR);	/* 2 RMR */
	sst_dac_read(DACREG_RMR);	/* 3 //  */
	sst_dac_read(DACREG_RMR);	/* 4 //  */
	cr0 = sst_dac_read(DACREG_RMR);	/* 5 CR0 */

	sst_dac_write(DACREG_WMA, 0);
	sst_dac_read(DACREG_RMR);
	sst_dac_read(DACREG_RMR);
	sst_dac_read(DACREG_RMR);
	sst_dac_read(DACREG_RMR);
	sst_dac_write(DACREG_RMR, (cr0 & 0xf0)
	              | DACREG_CR0_EN_INDEXED
	              | DACREG_CR0_8BIT
	              | DACREG_CR0_PWDOWN );
	/* so, now we are in indexed mode . dunno if its common, but
	   i find this way of doing things a little bit weird :p */

	udelay(300);
	cc = dac_i_read(DACREG_CC_I);
	switch (clock) {
	case VID_CLOCK:
		dac_i_write(DACREG_AC0_I, t->m);
		dac_i_write(DACREG_AC1_I, t->p << 6 | t->n);
		dac_i_write(DACREG_CC_I,
		            (cc & 0x0f) | DACREG_CC_CLKA | DACREG_CC_CLKA_C);
		break;
	case GFX_CLOCK:
		dac_i_write(DACREG_BD0_I, t->m);
		dac_i_write(DACREG_BD1_I, t->p << 6 | t->n);
		dac_i_write(DACREG_CC_I,
		            (cc & 0xf0) | DACREG_CC_CLKB | DACREG_CC_CLKB_D);
		break;
	default:
		dprintk("%s: wrong clock code '%d'\n",
		        __func__, clock);
		return 0;
		}
	udelay(300);

	/* power up the dac & return to "normal" non-indexed mode */
	dac_i_write(DACREG_CR0_I,
	            cr0 & ~DACREG_CR0_PWDOWN & ~DACREG_CR0_EN_INDEXED);
	return 1;
}

static int sst_set_pll_ics(struct fb_info *info,
		const struct pll_timing *t, const int clock)
{
	struct sstfb_par *par = info->par;
	u8 pll_ctrl;

	sst_dac_write(DACREG_ICS_PLLRMA, DACREG_ICS_PLL_CTRL);
	pll_ctrl = sst_dac_read(DACREG_ICS_PLLDATA);
	switch(clock) {
	case VID_CLOCK:
		sst_dac_write(DACREG_ICS_PLLWMA, 0x0);	/* CLK0, f0 */
		sst_dac_write(DACREG_ICS_PLLDATA, t->m);
		sst_dac_write(DACREG_ICS_PLLDATA, t->p << 5 | t->n);
		/* selects freq f0 for clock 0 */
		sst_dac_write(DACREG_ICS_PLLWMA, DACREG_ICS_PLL_CTRL);
		sst_dac_write(DACREG_ICS_PLLDATA,
		              (pll_ctrl & 0xd8)
		              | DACREG_ICS_CLK0
		              | DACREG_ICS_CLK0_0);
		break;
	case GFX_CLOCK :
		sst_dac_write(DACREG_ICS_PLLWMA, 0xa);	/* CLK1, fA */
		sst_dac_write(DACREG_ICS_PLLDATA, t->m);
		sst_dac_write(DACREG_ICS_PLLDATA, t->p << 5 | t->n);
		/* selects freq fA for clock 1 */
		sst_dac_write(DACREG_ICS_PLLWMA, DACREG_ICS_PLL_CTRL);
		sst_dac_write(DACREG_ICS_PLLDATA,
		              (pll_ctrl & 0xef) | DACREG_ICS_CLK1_A);
		break;
	default:
		dprintk("%s: wrong clock code '%d'\n",
		        __func__, clock);
		return 0;
		}
	udelay(300);
	return 1;
}

static void sst_set_vidmod_att_ti(struct fb_info *info, const int bpp)
{
	struct sstfb_par *par = info->par;
	u8 cr0;

	sst_dac_write(DACREG_WMA, 0); 	/* backdoor */
	sst_dac_read(DACREG_RMR);	/* read 4 times RMR */
	sst_dac_read(DACREG_RMR);
	sst_dac_read(DACREG_RMR);
	sst_dac_read(DACREG_RMR);
	/* the fifth time,  CR0 is read */
	cr0 = sst_dac_read(DACREG_RMR);

	sst_dac_write(DACREG_WMA, 0); 	/* backdoor */
	sst_dac_read(DACREG_RMR);	/* read 4 times RMR */
	sst_dac_read(DACREG_RMR);
	sst_dac_read(DACREG_RMR);
	sst_dac_read(DACREG_RMR);
	/* cr0 */
	switch(bpp) {
	case 16:
		sst_dac_write(DACREG_RMR, (cr0 & 0x0f) | DACREG_CR0_16BPP);
		break;
	default:
		dprintk("%s: bad depth '%u'\n", __func__, bpp);
		break;
	}
}

static void sst_set_vidmod_ics(struct fb_info *info, const int bpp)
{
	struct sstfb_par *par = info->par;

	switch(bpp) {
	case 16:
		sst_dac_write(DACREG_ICS_CMD, DACREG_ICS_CMD_16BPP);
		break;
	default:
		dprintk("%s: bad depth '%u'\n", __func__, bpp);
		break;
	}
}

/*
 * detect dac type
 * prerequisite : write to FbiInitx enabled, video and fbi and pci fifo reset,
 * dram refresh disabled, FbiInit remaped.
 * TODO: mmh.. maybe i should put the "prerequisite" in the func ...
 */


static struct dac_switch dacs[] __devinitdata = {
	{	.name		= "TI TVP3409",
		.detect		= sst_detect_ti,
		.set_pll	= sst_set_pll_att_ti,
		.set_vidmod	= sst_set_vidmod_att_ti },

	{	.name		= "AT&T ATT20C409",
		.detect		= sst_detect_att,
		.set_pll	= sst_set_pll_att_ti,
		.set_vidmod	= sst_set_vidmod_att_ti },
	{	.name		= "ICS ICS5342",
		.detect		= sst_detect_ics,
		.set_pll	= sst_set_pll_ics,
		.set_vidmod	= sst_set_vidmod_ics },
};

static int __devinit sst_detect_dactype(struct fb_info *info, struct sstfb_par *par)
{
	int i, ret = 0;

	for (i = 0; i < ARRAY_SIZE(dacs); i++) {
		ret = dacs[i].detect(info);
		if (ret)
			break;
	}
	if (!ret)
		return 0;
	f_dprintk("%s found %s\n", __func__, dacs[i].name);
	par->dac_sw = dacs[i];
	return 1;
}

/*
 * Internal Routines
 */
static int __devinit sst_init(struct fb_info *info, struct sstfb_par *par)
{
	u32 fbiinit0, fbiinit1, fbiinit4;
	struct pci_dev *dev = par->dev;
	struct pll_timing gfx_timings;
	struct sst_spec *spec;
	int Fout;
	int gfx_clock;

	spec = &voodoo_spec[par->type];
	f_ddprintk(" fbiinit0   fbiinit1   fbiinit2   fbiinit3   fbiinit4  "
	           " fbiinit6\n");
	f_ddprintk("%0#10x %0#10x %0#10x %0#10x %0#10x %0#10x\n",
	            sst_read(FBIINIT0), sst_read(FBIINIT1), sst_read(FBIINIT2),
	            sst_read(FBIINIT3), sst_read(FBIINIT4), sst_read(FBIINIT6));
	/* disable video clock */
	pci_write_config_dword(dev, PCI_VCLK_DISABLE, 0);

	/* enable writing to init registers, disable pci fifo */
	pci_write_config_dword(dev, PCI_INIT_ENABLE, PCI_EN_INIT_WR);
	/* reset video */
	sst_set_bits(FBIINIT1, VIDEO_RESET);
	sst_wait_idle();
	/* reset gfx + pci fifo */
	sst_set_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
	sst_wait_idle();

	/* unreset fifo */
	/*sst_unset_bits(FBIINIT0, FIFO_RESET);
	sst_wait_idle();*/
	/* unreset FBI */
	/*sst_unset_bits(FBIINIT0, FBI_RESET);
	sst_wait_idle();*/

	/* disable dram refresh */
	sst_unset_bits(FBIINIT2, EN_DRAM_REFRESH);
	sst_wait_idle();
	/* remap fbinit2/3 to dac */
	pci_write_config_dword(dev, PCI_INIT_ENABLE,
				PCI_EN_INIT_WR | PCI_REMAP_DAC );
	/* detect dac type */
	if (!sst_detect_dactype(info, par)) {
		printk(KERN_ERR "sstfb: unknown dac type.\n");
		//FIXME watch it: we are not in a safe state, bad bad bad.
		return 0;
	}

	/* set graphic clock */
	gfx_clock = spec->default_gfx_clock;
	if ((gfxclk >10 ) && (gfxclk < spec->max_gfxclk)) {
		printk(KERN_INFO "sstfb: Using supplied graphic freq : %dMHz\n", gfxclk);
		 gfx_clock = gfxclk *1000;
	} else if (gfxclk) {
		printk(KERN_WARNING "sstfb: %dMhz is way out of spec! Using default\n", gfxclk);
	}

	sst_calc_pll(gfx_clock, &Fout, &gfx_timings);
	par->dac_sw.set_pll(info, &gfx_timings, GFX_CLOCK);

	/* disable fbiinit remap */
	pci_write_config_dword(dev, PCI_INIT_ENABLE,
	                       PCI_EN_INIT_WR| PCI_EN_FIFO_WR );
	/* defaults init registers */
	/* FbiInit0: unreset gfx, unreset fifo */
	fbiinit0 = FBIINIT0_DEFAULT;
	fbiinit1 = FBIINIT1_DEFAULT;
	fbiinit4 = FBIINIT4_DEFAULT;
	par->vgapass = vgapass;
	if (par->vgapass)
		fbiinit0 &= ~DIS_VGA_PASSTHROUGH;
	else
		fbiinit0 |= DIS_VGA_PASSTHROUGH;
	if (slowpci) {
		fbiinit1 |= SLOW_PCI_WRITES;
		fbiinit4 |= SLOW_PCI_READS;
	} else {
		fbiinit1 &= ~SLOW_PCI_WRITES;
		fbiinit4 &= ~SLOW_PCI_READS;
	}
	sst_write(FBIINIT0, fbiinit0);
	sst_wait_idle();
	sst_write(FBIINIT1, fbiinit1);
	sst_wait_idle();
	sst_write(FBIINIT2, FBIINIT2_DEFAULT);
	sst_wait_idle();
	sst_write(FBIINIT3, FBIINIT3_DEFAULT);
	sst_wait_idle();
	sst_write(FBIINIT4, fbiinit4);
	sst_wait_idle();
	if (IS_VOODOO2(par)) {
		sst_write(FBIINIT6, FBIINIT6_DEFAULT);
		sst_wait_idle();
	}

	pci_write_config_dword(dev, PCI_INIT_ENABLE, PCI_EN_FIFO_WR);
	pci_write_config_dword(dev, PCI_VCLK_ENABLE, 0);
	return 1;
}

static void  __devexit sst_shutdown(struct fb_info *info)
{
	struct sstfb_par *par = info->par;
	struct pci_dev *dev = par->dev;
	struct pll_timing gfx_timings;
	int Fout;

	/* reset video, gfx, fifo, disable dram + remap fbiinit2/3 */
	pci_write_config_dword(dev, PCI_INIT_ENABLE, PCI_EN_INIT_WR);
	sst_set_bits(FBIINIT1, VIDEO_RESET | EN_BLANKING);
	sst_unset_bits(FBIINIT2, EN_DRAM_REFRESH);
	sst_set_bits(FBIINIT0, FBI_RESET | FIFO_RESET);
	sst_wait_idle();
	pci_write_config_dword(dev, PCI_INIT_ENABLE,
	                       PCI_EN_INIT_WR | PCI_REMAP_DAC);
	/* set 20Mhz gfx clock */
	sst_calc_pll(20000, &Fout, &gfx_timings);
	par->dac_sw.set_pll(info, &gfx_timings, GFX_CLOCK);
	/* TODO maybe shutdown the dac, vrefresh and so on... */
	pci_write_config_dword(dev, PCI_INIT_ENABLE,
	                       PCI_EN_INIT_WR);
	sst_unset_bits(FBIINIT0, FBI_RESET | FIFO_RESET | DIS_VGA_PASSTHROUGH);
	pci_write_config_dword(dev, PCI_VCLK_DISABLE,0);
	/* maybe keep fbiinit* and PCI_INIT_enable in the fb_info struct
	 * from start ? */
	pci_write_config_dword(dev, PCI_INIT_ENABLE, 0);

}

/*
 * Interface to the world
 */
static int  __devinit sstfb_setup(char *options)
{
	char *this_opt;

	if (!options || !*options)
		return 0;

	while ((this_opt = strsep(&options, ",")) != NULL) {
		if (!*this_opt) continue;

		f_ddprintk("option %s\n", this_opt);

		if (!strcmp(this_opt, "vganopass"))
			vgapass = 0;
		else if (!strcmp(this_opt, "vgapass"))
			vgapass = 1;
		else if (!strcmp(this_opt, "clipping"))
		        clipping = 1;
		else if (!strcmp(this_opt, "noclipping"))
		        clipping = 0;
		else if (!strcmp(this_opt, "fastpci"))
		        slowpci = 0;
		else if (!strcmp(this_opt, "slowpci"))
		        slowpci = 1;
		else if (!strncmp(this_opt, "mem:",4))
			mem = simple_strtoul (this_opt+4, NULL, 0);
		else if (!strncmp(this_opt, "gfxclk:",7))
			gfxclk = simple_strtoul (this_opt+7, NULL, 0);
		else
			mode_option = this_opt;
	}
	return 0;
}


static struct fb_ops sstfb_ops = {
	.owner		= THIS_MODULE,
	.fb_check_var	= sstfb_check_var,
	.fb_set_par	= sstfb_set_par,
	.fb_setcolreg	= sstfb_setcolreg,
	.fb_fillrect	= cfb_fillrect, /* sstfb_fillrect */
	.fb_copyarea	= cfb_copyarea, /* sstfb_copyarea */
	.fb_imageblit	= cfb_imageblit,
	.fb_ioctl	= sstfb_ioctl,
};

static int __devinit sstfb_probe(struct pci_dev *pdev,
			const struct pci_device_id *id)
{
	struct fb_info *info;
	struct fb_fix_screeninfo *fix;
	struct sstfb_par *par;
	struct sst_spec *spec;
	int err;

	/* Enable device in PCI config. */
	if ((err=pci_enable_device(pdev))) {
		printk(KERN_ERR "cannot enable device\n");
		return err;
	}

	/* Allocate the fb and par structures.  */
	info = framebuffer_alloc(sizeof(struct sstfb_par), &pdev->dev);
	if (!info)
		return -ENOMEM;

	pci_set_drvdata(pdev, info);
	
	par  = info->par;
	fix  = &info->fix;
	
	par->type = id->driver_data;
	spec = &voodoo_spec[par->type];
	f_ddprintk("found device : %s\n", spec->name);

	par->dev = pdev;
	par->revision = pdev->revision;

	fix->mmio_start = pci_resource_start(pdev,0);
	fix->mmio_len	= 0x400000;
	fix->smem_start = fix->mmio_start + 0x400000;

	if (!request_mem_region(fix->mmio_start, fix->mmio_len, "sstfb MMIO")) {
		printk(KERN_ERR "sstfb: cannot reserve mmio memory\n");
		goto fail_mmio_mem;
	}

	if (!request_mem_region(fix->smem_start, 0x400000,"sstfb FB")) {
		printk(KERN_ERR "sstfb: cannot reserve fb memory\n");
		goto fail_fb_mem;
	}

	par->mmio_vbase = ioremap_nocache(fix->mmio_start,
					fix->mmio_len);
	if (!par->mmio_vbase) {
		printk(KERN_ERR "sstfb: cannot remap register area %#lx\n",
		        fix->mmio_start);
		goto fail_mmio_remap;
	}
	info->screen_base = ioremap_nocache(fix->smem_start, 0x400000);
	if (!info->screen_base) {
		printk(KERN_ERR "sstfb: cannot remap framebuffer %#lx\n",
		        fix->smem_start);
		goto fail_fb_remap;
	}

	if (!sst_init(info, par)) {
		printk(KERN_ERR "sstfb: Init failed\n");
		goto fail;
	}
	sst_get_memsize(info, &fix->smem_len);
	strlcpy(fix->id, spec->name, sizeof(fix->id));

	printk(KERN_INFO "%s (revision %d) with %s dac\n",
		fix->id, par->revision, par->dac_sw.name);
	printk(KERN_INFO "framebuffer at %#lx, mapped to 0x%p, size %dMB\n",
	        fix->smem_start, info->screen_base,
	        fix->smem_len >> 20);

	f_ddprintk("regbase_virt: %#lx\n", par->mmio_vbase);
	f_ddprintk("membase_phys: %#lx\n", fix->smem_start);
	f_ddprintk("fbbase_virt: %p\n", info->screen_base);

	info->flags	= FBINFO_DEFAULT;
	info->fbops	= &sstfb_ops;
	info->pseudo_palette = par->palette;

	fix->type	= FB_TYPE_PACKED_PIXELS;
	fix->visual	= FB_VISUAL_TRUECOLOR;
	fix->accel	= FB_ACCEL_NONE;  /* FIXME */
	/*
	 * According to the specs, the linelength must be of 1024 *pixels*
	 * and the 24bpp mode is in fact a 32 bpp mode (and both are in
	 * fact dithered to 16bit).
	 */
	fix->line_length = 2048; /* default value, for 24 or 32bit: 4096 */
	
	fb_find_mode(&info->var, info, mode_option, NULL, 0, NULL, 16);

	if (sstfb_check_var(&info->var, info)) {
		printk(KERN_ERR "sstfb: invalid video mode.\n");
		goto fail;
	}

	if (sstfb_set_par(info)) {
		printk(KERN_ERR "sstfb: can't set default video mode.\n");
		goto fail;
	}
	
	if (fb_alloc_cmap(&info->cmap, 256, 0)) {
		printk(KERN_ERR "sstfb: can't alloc cmap memory.\n");
		goto fail;
	}

	/* register fb */
	info->device = &pdev->dev;
	if (register_framebuffer(info) < 0) {
		printk(KERN_ERR "sstfb: can't register framebuffer.\n");
		goto fail_register;
	}

	sstfb_clear_screen(info);

	if (device_create_file(info->dev, &device_attrs[0]))
		printk(KERN_WARNING "sstfb: can't create sysfs entry.\n");


	printk(KERN_INFO "fb%d: %s frame buffer device at 0x%p\n",
	       info->node, fix->id, info->screen_base);

	return 0;

fail_register:
	fb_dealloc_cmap(&info->cmap);
fail:
	iounmap(info->screen_base);
fail_fb_remap:
	iounmap(par->mmio_vbase);
fail_mmio_remap:
	release_mem_region(fix->smem_start, 0x400000);
fail_fb_mem:
	release_mem_region(fix->mmio_start, info->fix.mmio_len);
fail_mmio_mem:
	framebuffer_release(info);
	return -ENXIO; 	/* no voodoo detected */
}

static void __devexit sstfb_remove(struct pci_dev *pdev)
{
	struct sstfb_par *par;
	struct fb_info *info;

	info = pci_get_drvdata(pdev);
	par = info->par;
	
	device_remove_file(info->dev, &device_attrs[0]);
	sst_shutdown(info);
	iounmap(info->screen_base);
	iounmap(par->mmio_vbase);
	release_mem_region(info->fix.smem_start, 0x400000);
	release_mem_region(info->fix.mmio_start, info->fix.mmio_len);
	fb_dealloc_cmap(&info->cmap);
	unregister_framebuffer(info);
	framebuffer_release(info);
}


static const struct pci_device_id sstfb_id_tbl[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_VOODOO ),
		.driver_data = ID_VOODOO1, },
	{ PCI_DEVICE(PCI_VENDOR_ID_3DFX, PCI_DEVICE_ID_3DFX_VOODOO2),
		.driver_data = ID_VOODOO2, },
	{ 0 },
};

static struct pci_driver sstfb_driver = {
	.name		= "sstfb",
	.id_table	= sstfb_id_tbl,
	.probe		= sstfb_probe,
	.remove		= __devexit_p(sstfb_remove),
};


static int __devinit sstfb_init(void)
{
	char *option = NULL;

	if (fb_get_options("sstfb", &option))
		return -ENODEV;
	sstfb_setup(option);

	return pci_register_driver(&sstfb_driver);
}

static void __devexit sstfb_exit(void)
{
	pci_unregister_driver(&sstfb_driver);
}


module_init(sstfb_init);
module_exit(sstfb_exit);

MODULE_AUTHOR("(c) 2000,2002 Ghozlane Toumi <gtoumi@laposte.net>");
MODULE_DESCRIPTION("FBDev driver for 3dfx Voodoo Graphics and Voodoo2 based video boards");
MODULE_LICENSE("GPL");

module_param(mem, int, 0);
MODULE_PARM_DESC(mem, "Size of frame buffer memory in MB (1, 2, 4 MB, default=autodetect)");
module_param(vgapass, bool, 0);
MODULE_PARM_DESC(vgapass, "Enable VGA PassThrough mode (0 or 1) (default=0)");
module_param(clipping, bool, 0);
MODULE_PARM_DESC(clipping, "Enable clipping (slower, safer) (0 or 1) (default=1)");
module_param(gfxclk, int, 0);
MODULE_PARM_DESC(gfxclk, "Force graphic chip frequency in MHz. DANGEROUS. (default=auto)");
module_param(slowpci, bool, 0);
MODULE_PARM_DESC(slowpci, "Uses slow PCI settings (0 or 1) (default=0)");
module_param(mode_option, charp, 0);
MODULE_PARM_DESC(mode_option, "Initial video mode (default=" DEFAULT_VIDEO_MODE ")");