* Tvp302[056] Viewpoint Video Interface Palette.

#include <u.h>
#include <libc.h>
#include <bio.h>

#include "pci.h"
#include "vga.h"

/*
* Tvp302[056] Viewpoint Video Interface Palette.
* Assumes hooked up to an S3 86C928 or S3 Vision964.
*/
enum {
Index = 0x06, /* Index register */
Data = 0x07, /* Data register */

Id = 0x3F, /* ID Register */
Tvp3020 = 0x20,
Tvp3025 = 0x25,
Tvp3026 = 0x26,
};

/*
* The following two arrays give read (bit 0) and write (bit 1)
* permissions on the direct and index registers. Bits 4 and 5
* are for the Tvp3025. The Tvp3020 has only 8 direct registers.
*/
static uchar directreg[32] = {
0x33, 0x33, 0x33, 0x33, 0x00, 0x00, 0x33, 0x33,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
0x33, 0x33, 0x11, 0x33, 0x33, 0x33, 0x33, 0x33,
};

static uchar indexreg[64] = {
0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x00,
0x02, 0x02, 0x33, 0x00, 0x00, 0x00, 0x30, 0x30,
0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x30, 0x00,
0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
0x33, 0x33, 0x33, 0x33, 0x30, 0x30, 0x30, 0x30,
0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
0x33, 0x30, 0x33, 0x11, 0x11, 0x11, 0x22, 0x11,
};

/*
* Check the index register access is valid.
* Return the number of direct registers.
*/
static uchar
checkindex(uchar index, uchar access)
{
uchar crt55;
static uchar id;

if(id == 0){
crt55 = vgaxi(Crtx, 0x55) & 0xFC;
vgaxo(Crtx, 0x55, crt55|((Index>>2) & 0x03));
vgao(dacxreg[Index & 0x03], Id);

id = vgai(dacxreg[Data & 0x03]);
vgaxo(Crtx, 0x55, crt55);
}

if(index == 0xFF)
return id;

access &= 0x03;
switch(id){

case Tvp3020:
break;

case Tvp3025:
case Tvp3026:
access = access<<4;
break;

default:
Bprint(&stdout, "%s: unknown chip id - 0x%2.2X\n", tvp3020.name, id);
break;
}

if(index > sizeof(indexreg) || (indexreg[index] & access) == 0)
error("%s: bad register index - 0x%2.2X\n", tvp3020.name, index);

return id;
}

static uchar
tvp3020io(uchar reg, uchar data)
{
uchar crt55;

crt55 = vgaxi(Crtx, 0x55) & 0xFC;
vgaxo(Crtx, 0x55, crt55|((reg>>2) & 0x03));
vgao(dacxreg[reg & 0x03], data);

return crt55;
}

uchar
tvp3020i(uchar reg)
{
uchar crt55, r;

crt55 = vgaxi(Crtx, 0x55) & 0xFC;
vgaxo(Crtx, 0x55, crt55|((reg>>2) & 0x03));
r = vgai(dacxreg[reg & 0x03]);
vgaxo(Crtx, 0x55, crt55);

return r;
}

uchar
tvp3020xi(uchar index)
{
uchar crt55, r;

checkindex(index, 0x01);

crt55 = tvp3020io(Index, index);
r = vgai(dacxreg[Data & 0x03]);
vgaxo(Crtx, 0x55, crt55);

return r;
}

void
tvp3020o(uchar reg, uchar data)
{
uchar crt55;

crt55 = tvp3020io(reg, data);
vgaxo(Crtx, 0x55, crt55);
}

void
tvp3020xo(uchar index, uchar data)
{
uchar crt55;

checkindex(index, 0x02);

crt55 = tvp3020io(Index, index);
vgao(dacxreg[Data & 0x03], data);
vgaxo(Crtx, 0x55, crt55);
}

static void
options(Vga*, Ctlr* ctlr)
{
ctlr->flag |= Hclk2|Hextsid|Hpvram|Henhanced|Foptions;
}

static void
init(Vga* vga, Ctlr* ctlr)
{
ulong grade;
char *p;

/*
* Work out the part speed-grade from name. Name can have,
* e.g. '-135' on the end for 135MHz part.
*/
grade = 110000000;
if(p = strrchr(ctlr->name, '-'))
grade = strtoul(p+1, 0, 0) * 1000000;

/*
* If we don't already have a desired pclk,
* take it from the mode.
* Check it's within range.
*/
if(vga->f[0] == 0)
vga->f[0] = vga->mode->frequency;
if(vga->f[0] > grade)
error("%s: invalid pclk - %ld\n", ctlr->name, vga->f[0]);

/*
* Determine whether to use clock-doubler or not.
*/
if(vga->f[0] > 85000000){
vga->f[0] /= 2;
resyncinit(vga, ctlr, Uclk2, 0);
}

ctlr->flag |= Finit;
}

static void
load(Vga* vga, Ctlr* ctlr)
{
uchar x;

/*
* Input Clock Selection:
* VGA CLK0
* enhanced CLK1
* doubled if necessary.
*/
x = 0x00;
if(ctlr->flag & Uenhanced)
x |= 0x01;
if(ctlr->flag & Uclk2)
x |= 0x10;
tvp3020xo(0x1A, x);

/*
* Output Clock Selection:
* VGA default VGA
* enhanced RCLK=SCLK=/8, VCLK/4
*/
x = 0x3E;
if(ctlr->flag & Uenhanced)
x = 0x53;
tvp3020xo(0x1B, x);

/*
* Auxiliary Control:
* default settings - self-clocked, palette graphics, no zoom
* Colour Key Control:
* default settings - pointing to palette graphics
* Mux Control Register 1:
* pseudo colour
*/
tvp3020xo(0x29, 0x09);
tvp3020xo(0x38, 0x10);
tvp3020xo(0x18, 0x80);

/*
* Mux Control Register 2:
* VGA default VGA
* enhanced 8-bpp, 8:1 mux, 64-bit pixel-bus width
*/
x = 0x98;
if(ctlr->flag & Uenhanced){
if(vga->mode->z == 8)
x = 0x1C;
else if(vga->mode->z == 1)
x = 0x04;
}
tvp3020xo(0x19, x);

/*
* General Control:
* output sync polarity
* It's important to set this properly and to turn off the
* VGA controller H and V syncs. Can't be set in VGA mode.
*/
x = 0x00;
if((vga->misc & 0x40) == 0)
x |= 0x01;
if((vga->misc & 0x80) == 0)
x |= 0x02;
tvp3020xo(0x1D, x);
vga->misc |= 0xC0;
vgao(MiscW, vga->misc);

/*
* Select the DAC via the General Purpose I/O
* Register and Pins.
* Guesswork by looking at register dumps.
*/
tvp3020xo(0x2A, 0x1F);
if(ctlr->flag & Uenhanced)
x = 0x1D;
else
x = 0x1C;
tvp3020xo(0x2B, x);

ctlr->flag |= Fload;
}

static void
dump(Vga*, Ctlr* ctlr)
{
uchar access;
int i;

access = 0x01;
if(checkindex(0x00, 0x01) != Tvp3020)
access <<= 4;

printitem(ctlr->name, "direct");
for(i = 0; i < 8; i++){
if(directreg[i] & access)
printreg(tvp3020i(i));
else
printreg(0xFF);
}

printitem(ctlr->name, "index");
for(i = 0; i < sizeof(indexreg); i++){
if(indexreg[i] & access)
printreg(tvp3020xi(i));
else
printreg(0xFF);
}
}

Ctlr tvp3020 = {
"tvp3020", /* name */
0, /* snarf */
options, /* options */
init, /* init */
load, /* load */
dump, /* dump */
};