1994/0624/pc/vgabt485.c (diff list | history)

pc/vgabt485.c on 1994/0624
1994/0624		#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include <libg.h> #include "screen.h" #include "vga.h" /* * Hardware graphics cursor support for * Brooktree Bt485 Monolithic True-Color RAMDAC. * Assumes hooked up to an S3 86C928. * * BUGS: * 64x64x2 cursor always used; * no support for interlaced mode. */ enum { AddrW = 0x00, /* Address register; palette/cursor RAM write */ Palette = 0x01, /* 6/8-bit color palette data */ Pmask = 0x02, /* Pixel mask register */ AddrR = 0x03, /* Address register; palette/cursor RAM read */ ColorW = 0x04, /* Address register; cursor/overscan color write */ Color = 0x05, /* Cursor/overscan color data */ Cmd0 = 0x06, /* Command register 0 */ ColorR = 0x07, /* Address register; cursor/overscan color read */ Cmd1 = 0x08, /* Command register 1 */ Cmd2 = 0x09, /* Command register 2 */ Status = 0x0A, /* Status */ Cmd3 = 0x1A, /* Command register 3 */ Cram = 0x0B, /* Cursor RAM array data */ Cxlr = 0x0C, /* Cursor x-low register */ Cxhr = 0x0D, /* Cursor x-high register */ Cylr = 0x0E, /* Cursor y-low register */ Cyhr = 0x0F, /* Cursor y-high register */ Nreg = 0x10, }; /* * Lower 2-bits of indirect DAC register * addressing. */ static ushort dacxreg[4] = { DACWx, DACData, DACMask, DACSts }; static uchar bt485io(uchar reg) { uchar crt55, cr0; crt55 = vgaxi(Crtx, 0x55) & 0xFC; if((reg & 0x0F) == Status){ /* * 1,2: Set indirect addressing for Status or * Cmd3 - set bit7 of Cr0. */ vgaxo(Crtx, 0x55, crt55|((Cmd0>>2) & 0x03)); cr0 = vgai(dacxreg[Cmd0 & 0x03])|0x80; vgao(dacxreg[Cmd0 & 0x03], cr0); /* * 3,4: Set the index into the Write register, * index == 0x00 for Status, 0x01 for Cmd3. */ vgaxo(Crtx, 0x55, crt55|((AddrW>>2) & 0x03)); vgao(dacxreg[AddrW & 0x03], (reg == Status) ? 0x00: 0x01); /* * 5,6: Get the contents of the appropriate * register at 0x0A. */ } return crt55; } static uchar bt485i(uchar reg) { uchar crt55, r; crt55 = bt485io(reg); vgaxo(Crtx, 0x55, crt55|((reg>>2) & 0x03)); r = vgai(dacxreg[reg & 0x03]); vgaxo(Crtx, 0x55, crt55); return r; } static void bt485o(uchar reg, uchar data) { uchar crt55; crt55 = bt485io(reg); vgaxo(Crtx, 0x55, crt55|((reg>>2) & 0x03)); vgao(dacxreg[reg & 0x03], data); vgaxo(Crtx, 0x55, crt55); } static Point hotpoint; static void load(Cursor *c) { uchar r; int x, y; lock(&pallettelock); /* * Turn cursor off; * put cursor into 64x64x2 mode and clear MSBs of address; * clear LSBs of address; */ r = bt485i(Cmd2) & 0xFC; bt485o(Cmd2, r); r = (bt485i(Cmd3) & 0xFC)|0x04; bt485o(Cmd3, r); bt485o(AddrW, 0x00); /* * Now load the cursor RAM array, both planes. * The cursor is 16x16, the array 64x64; put * the cursor in the top left. The 0,0 cursor * point is bottom-right, so positioning will * have to take that into account. */ for(y = 0; y < 64; y++){ for(x = 0; x < 64/8; x++){ if(x < 16/8 && y < 16) bt485o(Cram, c->clr[x+y*2]); else bt485o(Cram, 0x00); } } for(y = 0; y < 64; y++){ for(x = 0; x < 64/8; x++){ if(x < 16/8 && y < 16) bt485o(Cram, c->set[x+y*2]); else bt485o(Cram, 0x00); } } /* * Initialise the cursor hot-point * and enable the cursor. */ hotpoint.x = 64+c->offset.x; hotpoint.y = 64+c->offset.y; r = (bt485i(Cmd2) & 0xFC)|0x01; bt485o(Cmd2, r); unlock(&pallettelock); } static void enable(void) { uchar r; lock(&pallettelock); /* * Turn cursor off. */ r = bt485i(Cmd2) & 0xFC; bt485o(Cmd2, r); /* * Overscan colour, * cursor colour 1 (white), * cursor colour 2, 3 (black). */ bt485o(ColorW, 0x00); bt485o(Color, 0xFF); bt485o(Color, 0xFF); bt485o(Color, 0xFF); bt485o(Color, 0xFF); bt485o(Color, 0xFF); bt485o(Color, 0xFF); bt485o(Color, 0x00); bt485o(Color, 0x00); bt485o(Color, 0x00); bt485o(Color, 0x00); bt485o(Color, 0x00); bt485o(Color, 0x00); unlock(&pallettelock); /* * Finally, enable * the hardware cursor external operation mode; * cursor control enable for Bt485 DAC. * The #9GXE cards seem to need the 86C928 Bt485 support * enabled in order to work at all in enhanced mode. */ r = vgaxi(Crtx, 0x55)|0x20; vgaxo(Crtx, 0x55, r); r = vgaxi(Crtx, 0x45)|0x20; vgaxo(Crtx, 0x45, r); } static int move(Point p) { int x, y; if(canlock(&pallettelock) == 0) return 1; x = p.x+hotpoint.x; y = p.y+hotpoint.y; bt485o(Cxlr, x & 0xFF); bt485o(Cxhr, (x>>8) & 0x0F); bt485o(Cylr, y & 0xFF); bt485o(Cyhr, (y>>8) & 0x0F); unlock(&pallettelock); return 0; } static void disable(void) { uchar r; /* * Disable * cursor mode 3; * cursor control enable for Bt485 DAC; * the hardware cursor external operation mode. */ lock(&pallettelock); r = bt485i(Cmd2) & ~0x03; bt485o(Cmd2, r); unlock(&pallettelock); r = vgaxi(Crtx, 0x45) & ~0x20; vgaxo(Crtx, 0x45, r); r = vgaxi(Crtx, 0x55) & ~0x20; vgaxo(Crtx, 0x55, r); } Hwgc bt485hwgc = { "bt485hwgc", enable, load, move, disable, };