* ATI Mach32. Some hope.

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

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

/*
* ATI Mach32. Some hope.
* No support for accelerator so can only do up to 1024x768.
*
* All ATI Extended Registers are addressed using the modified index
* index = (0x02<<6)|(index & 0x3F);
* so registers 0x00->0x3F map to 0x80->0xBF, but we will only ever
* look at a few in the range 0xA0->0xBF. In this way we can stash
* them in the vga->crt[] array.
*/
enum {
Advfunc = 0x4AE8, /* Advanced Function Control Register */
Clocksel = 0x4AEE, /* Clock Select Register */
Misc = 0x36EE, /* Miscellaneous Register */
Membndry = 0x42EE, /* Memory Boundary Register */
Memcfg = 0x5EEE, /* Memory Control Register */
};

typedef struct {
ushort advfunc;
ushort clocksel;
ushort misc;
ushort membndry;
ushort memcfg;
} Mach32;

/*
* There are a number of possible clock generator chips for these
* boards, and I don't know how to find out which is installed, other
* than by looking at the board. So, pick a subset that will work for
* all.
*/
typedef struct {
ulong frequency;
uchar b8; /* <6> - divide by 2 */
uchar b9; /* <1> - bit <3> of frequency index */
uchar be; /* <4> - bit <2> of frequency index */
uchar misc; /* <3:2> - bits <1:0> of frequency index */
} Clock;

static Clock clocks[] = {
{ VgaFreq0, 0x40, 0x02, 0x00, 0x00, },
{ 32000000, 0x00, 0x00, 0x10, 0x04, },
{ 40000000, 0x00, 0x02, 0x10, 0x00, },
{ 44900000, 0x00, 0x02, 0x00, 0x0C, },
{ 65000000, 0x00, 0x02, 0x10, 0x0C, },
{ 75000000, 0x00, 0x02, 0x10, 0x08, },
{ 0, },
};

static ulong atix;

static uchar
atixi(uchar index)
{
outportb(atix, index);
return inportb(atix+1);
}

static void
atixo(uchar index, uchar data)
{
outportw(atix, (data<<8)|index);
}

static void
atixinit(Vga* vga, Ctlr*)
{
uchar b;
Mach32 *mach32;

/*
* We could try to read in a part of the BIOS and try to determine
* the extended register address, but since we can't determine the offset value,
* we'll just have to assume the defaults all round.
*/
atix = 0x1CE;

/*
* Unlock the ATI Extended Registers.
* We leave them unlocked from now on.
* Why does this chip have so many
* lock bits?
*/
if((b = atixi(0xB8)) & 0x3F)
atixo(0xB8, b & 0xC0);
b = atixi(0xAB);
atixo(0xAB, b & ~0x18);
atixo(0xB4, 0x00);
b = atixi(0xB9);
atixo(0xB9, b & ~0x80);
b = atixi(0xBE);
atixo(0xBE, b|0x09);

if(vga->private == 0)
vga->private = alloc(sizeof(mach32));
}

static void
snarf(Vga* vga, Ctlr* ctlr)
{
int i;
Mach32 *mach32;

atixinit(vga, ctlr);
for(i = 0xA0; i < 0xC0; i++)
vga->crt[i] = atixi(i);

mach32 = vga->private;
mach32->advfunc = inportw(Advfunc);
mach32->clocksel = inportw(Clocksel);
mach32->misc = inportw(Misc);
mach32->membndry = inportw(Membndry);
mach32->memcfg = inportw(Memcfg);

/*
* Memory size.
*/
switch((mach32->misc>>2) & 0x03){

case 0:
vga->vmz = 512*1024;
break;

case 1:
vga->vmz = 1024*1024;
break;

case 2:
vga->vmz = 2*1024*1024;
break;

case 3:
vga->vmz = 4*1024*1024;
break;
}

ctlr->flag |= Fsnarf;
}

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

static void
init(Vga* vga, Ctlr* ctlr)
{
Clock *clockp;
Mode *mode;

mode = vga->mode;

if(vga->f[0] == 0)
vga->f[0] = vga->mode->frequency;
for(clockp = clocks; clockp->frequency; clockp++){
if(clockp->frequency > vga->f[0]+100000)
continue;
if(clockp->frequency > vga->f[0]-100000)
break;
}
if(clockp->frequency == 0)
error("%s: no suitable clock for %lud\n",
ctlr->name, vga->f[0]);

vga->crt[0xB0] &= 0xDA;
vga->crt[0xB1] &= 0x87;
vga->crt[0xB5] &= 0x7E;
vga->crt[0xB6] &= 0xE2;
vga->crt[0xB3] &= 0xAF;
vga->crt[0xA6] &= 0xFE;
vga->crt[0xA7] &= 0xF4;

/*
* 256-colour linear addressing.
*/
if(mode->z == 8){
vga->graphics[0x05] = 0x00;
vga->attribute[0x10] &= ~0x40;
vga->crt[0x13] = (mode->x/8)/2;
vga->crt[0x14] = 0x00;
vga->crt[0x17] = 0xE3;

vga->crt[0xB0] |= 0x20;
vga->crt[0xB6] |= 0x04;
}
vga->attribute[0x11] = 0x00;
vga->crt[0xB6] |= 0x01;
vga->crt[0xBE] &= ~0x04;

/*
* Do the clock index bits.
*/
vga->crt[0xB9] &= 0xFD;
vga->crt[0xB8] &= 0x3F;
vga->crt[0xBE] &= 0xE5;

vga->crt[0xB8] |= clockp->b8;
vga->crt[0xB9] |= clockp->b9;
vga->crt[0xBE] |= clockp->be;
vga->misc |= clockp->misc;

if(vga->mode->interlace == 'v')
vga->crt[0xBE] |= 0x02;

/*
* Turn off 128Kb CPU address bit so
* we only have a 64Kb aperture at 0xA0000.
*/
vga->crt[0xBD] &= ~0x04;

ctlr->flag |= Finit;
}

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

/*
* Make sure we are in VGA mode,
* and that we have access to all the video memory through
* the 64Kb VGA aperture by disabling and linear aperture
* and memory boundary.
*/
outportw(Clocksel, 0x0000);
x = inportw(Memcfg) & ~0x0003;
outportw(Memcfg, x);
outportw(Membndry, 0x0000);

atixo(0xB0, vga->crt[0xB0]);
atixo(0xB1, vga->crt[0xB1]);
atixo(0xB5, vga->crt[0xB5]);
atixo(0xB6, vga->crt[0xB6]);
atixo(0xB3, vga->crt[0xB3]);
atixo(0xA6, vga->crt[0xA6]);
atixo(0xA7, vga->crt[0xA7]);
atixo(0xB8, vga->crt[0xB8]);
atixo(0xB9, vga->crt[0xB9]);
atixo(0xBE, vga->crt[0xBE]);
vgao(MiscW, vga->misc);

ctlr->flag |= Fload;
}

static void
dump(Vga* vga, Ctlr* ctlr)
{
int i;
Mach32 *mach32;

printitem(ctlr->name, "ATIX");
for(i = 0xA0; i < 0xC0; i++)
printreg(vga->crt[i]);

if((mach32 = vga->private) == 0)
return;

printitem(ctlr->name, "ADVFUNC");
Bprint(&stdout, "%.4ux\n", mach32->advfunc);
printitem(ctlr->name, "CLOCKSEL");
Bprint(&stdout, "%.4ux\n", mach32->clocksel);
printitem(ctlr->name, "MISC");
Bprint(&stdout, "%.4ux\n", mach32->misc);
printitem(ctlr->name, "MEMBNDRY");
Bprint(&stdout, "%.4ux\n", mach32->membndry);
printitem(ctlr->name, "MEMCFG");
Bprint(&stdout, "%.4ux\n", mach32->memcfg);
}

Ctlr mach32 = {
"mach32", /* name */
snarf, /* snarf */
options, /* options */
init, /* init */
load, /* load */
dump, /* dump */
};