* Clocks which require fiddling with the S3 registers

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

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

/*
* Clocks which require fiddling with the S3 registers
* in order to be loaded.
*/
static void
setcrt42(Vga* vga, Ctlr* ctlr, uchar index)
{
trace("%s->clock->setcrt42\n", ctlr->name);

vgao(MiscW, vga->misc & ~0x0C);
outportb(Crtx+1, 0x00);

vga->crt[0x42] = (vga->crt[0x42] & 0xF0)|index;
vgao(MiscW, vga->misc);
vgaxo(Crtx, 0x42, vga->crt[0x42]);
}

static void
icd2061aload(Vga* vga, Ctlr* ctlr)
{
ulong sdata;
int i;
uchar crt42;

trace("%s->clock->icd2061aload\n", ctlr->name);
/*
* The serial word to be loaded into the icd2061a is
* (2<<21)|(vga->i<<17)|((vga->n)<<10)|(vga->p<<7)|vga->d
* Always select ICD2061A REG2.
*/
sdata = (2<<21)|(vga->i[0]<<17)|((vga->n[0])<<10)|(vga->p[0]<<7)|vga->d[0];

/*
* The display should be already off to enable us to clock the
* serial data word into either MiscW or Crt42.
*
* Set the Misc register to make clock-select-out the contents of
* register Crt42. Must turn the sequencer off when changing bits
* <3:2> of Misc. Also, must set Crt42 to 0 before setting <3:2>
* of Misc due to a hardware glitch.
*/
vgao(MiscW, vga->misc & ~0x0C);
crt42 = vgaxi(Crtx, 0x42) & 0xF0;
outportb(Crtx+1, 0x00);

vgaxo(Seqx, 0x00, 0x00);
vgao(MiscW, vga->misc|0x0C);
vgaxo(Seqx, 0x00, 0x03);

/*
* Unlock the ICD2061A. The unlock sequence is at least 5 low-to-high
* transitions of CLK with DATA high, followed by a single low-to-high
* transition of CLK with DATA low.
* Using Crt42, CLK is bit0, DATA is bit 1. If we used MiscW, they'd
* be bits 2 and 3 respectively.
*/
outportb(Crtx+1, crt42|0x00); /* -DATA|-CLK */
outportb(Crtx+1, crt42|0x02); /* +DATA|-CLK */
for(i = 0; i < 5; i++){
outportb(Crtx+1, crt42|0x03); /* +DATA|+CLK */
outportb(Crtx+1, crt42|0x02); /* +DATA|-CLK */
}
outportb(Crtx+1, crt42|0x00); /* -DATA|-CLK */
outportb(Crtx+1, crt42|0x01); /* -DATA|+CLK */

/*
* Now write the serial data word, framed by a start-bit and a stop-bit.
* The data is written using a modified Manchester encoding such that a
* data-bit is sampled on the rising edge of CLK and the complement of
* the data-bit is sampled on the previous falling edge of CLK.
*/
outportb(Crtx+1, crt42|0x00); /* -DATA|-CLK (start-bit) */
outportb(Crtx+1, crt42|0x01); /* -DATA|+CLK */

for(i = 0; i < 24; i++){ /* serial data word */
if(sdata & 0x01){
outportb(Crtx+1, crt42|0x01); /* -DATA|+CLK */
outportb(Crtx+1, crt42|0x00); /* -DATA|-CLK (falling edge) */
outportb(Crtx+1, crt42|0x02); /* +DATA|-CLK */
outportb(Crtx+1, crt42|0x03); /* +DATA|+CLK (rising edge) */
}
else {
outportb(Crtx+1, crt42|0x03); /* +DATA|+CLK */
outportb(Crtx+1, crt42|0x02); /* +DATA|-CLK (falling edge) */
outportb(Crtx+1, crt42|0x00); /* -DATA|-CLK */
outportb(Crtx+1, crt42|0x01); /* -DATA|+CLK (rising edge) */
}
sdata >>= 1;
}

outportb(Crtx+1, crt42|0x03); /* +DATA|+CLK (stop-bit) */
outportb(Crtx+1, crt42|0x02); /* +DATA|-CLK */
outportb(Crtx+1, crt42|0x03); /* +DATA|+CLK */

/*
* We always use REG2 in the ICD2061A.
*/
setcrt42(vga, ctlr, 0x02);
}

static void
ch9294load(Vga* vga, Ctlr* ctlr)
{
trace("%s->clock->ch9294load\n", ctlr->name);

setcrt42(vga, ctlr, vga->i[0]);
}

static void
tvp3025load(Vga* vga, Ctlr* ctlr)
{
uchar crt5c, x;

trace("%s->clock->tvp3025load\n", ctlr->name);

/*
* Crt5C bit 5 is RS4.
* Clear it to select TVP3025 registers for
* the calls to tvp302xo().
*/
crt5c = vgaxi(Crtx, 0x5C);
vgaxo(Crtx, 0x5C, crt5c & ~0x20);

tvp3020xo(0x2C, 0x00);
tvp3020xo(0x2D, vga->d[0]);
tvp3020xo(0x2D, vga->n[0]);
tvp3020xo(0x2D, 0x08|vga->p[0]);

tvp3020xo(0x2F, 0x01);
tvp3020xo(0x2F, 0x01);
tvp3020xo(0x2F, vga->p[0]);
x = 0x54;
if(vga->ctlr && (vga->ctlr->flag & Uenhanced))
x = 0xC4;
tvp3020xo(0x1E, x);

vgaxo(Crtx, 0x5C, crt5c);
vgao(MiscW, vga->misc);

ctlr->flag |= Fload;
}

static void
tvp3026load(Vga* vga, Ctlr* ctlr)
{
trace("%s->clock->tvp3026load\n", ctlr->name);

if((vga->misc & 0x0C) != 0x0C && vga->mode->z == 1){
tvp3026xo(0x1A, 0x07);
tvp3026xo(0x18, 0x80);
tvp3026xo(0x19, 0x98);
tvp3026xo(0x2C, 0x2A);
tvp3026xo(0x2F, 0x00);
tvp3026xo(0x2D, 0x00);
tvp3026xo(0x39, 0x18);
setcrt42(vga, ctlr, 0);
}
else if(vga->mode->z == 8){
tvp3026xo(0x1A, 0x05);
tvp3026xo(0x18, 0x80);
tvp3026xo(0x19, 0x4C);
tvp3026xo(0x2C, 0x2A);
tvp3026xo(0x2F, 0x00);
tvp3026xo(0x2D, 0x00);

tvp3026xo(0x2C, 0x00);
tvp3026xo(0x2D, 0xC0|vga->n[0]);
tvp3026xo(0x2D, vga->m[0] & 0x3F);
tvp3026xo(0x2D, 0xB0|vga->p[0]);
while(!(tvp3026xi(0x2D) & 0x40))
;

tvp3026xo(0x39, 0x38|vga->q[1]);
tvp3026xo(0x2C, 0x00);
tvp3026xo(0x2F, 0xC0|vga->n[1]);
tvp3026xo(0x2F, vga->m[1]);
tvp3026xo(0x2F, 0xF0|vga->p[1]);
while(!(tvp3026xi(0x2F) & 0x40))
;

setcrt42(vga, ctlr, 3);
}

ctlr->flag |= Fload;
}

static struct {
char* name;
void (*load)(Vga*, Ctlr*);
} clocks[] = {
{ "icd2061a", icd2061aload, },
{ "ch9294", ch9294load, },
{ "tvp3025clock", tvp3025load, },
{ "tvp3026clock", tvp3026load, },
{ 0 },
};

static void
init(Vga* vga, Ctlr* ctlr)
{
char name[Namelen+1], *p;
int i;

if(vga->clock == 0)
return;

/*
* Check we know about it.
*/
strncpy(name, vga->clock->name, Namelen);
name[Namelen] = 0;
if(p = strchr(name, '-'))
*p = 0;
for(i = 0; clocks[i].name; i++){
if(strcmp(clocks[i].name, name) == 0)
break;
}
if(clocks[i].name == 0)
error("%s: unknown clock \"%s\"\n", ctlr->name, vga->clock->name);

if(vga->clock->init && (vga->clock->flag & Finit) == 0)
(*vga->clock->init)(vga, vga->clock);

/*
* If we don't already have a desired pclk,
* take it from the mode.
*/
if(vga->f[0] == 0)
vga->f[0] = vga->mode->frequency;
if(vga->f[0] != VgaFreq0 && vga->f[0] != VgaFreq1)
vga->misc |= 0x0C;

ctlr->flag |= Finit;
}

static void
load(Vga* vga, Ctlr* ctlr)
{
char name[Namelen+1], *p;
int i;

if(vga->clock == 0 || (vga->clock->flag & Fload))
return;

strncpy(name, vga->clock->name, Namelen);
name[Namelen] = 0;
if(p = strchr(name, '-'))
*p = 0;

for(i = 0; clocks[i].name; i++){
if(strcmp(clocks[i].name, name))
continue;
clocks[i].load(vga, ctlr);
if(strcmp(clocks[i].name, "icd2061a") == 0){
clocks[i].load(vga, ctlr);
clocks[i].load(vga, ctlr);
}

ctlr->flag |= Fload;
return;
}
}

Ctlr s3clock = {
"s3clock", /* name */
0, /* snarf */
0, /* options */
init, /* init */
load, /* load */
0, /* dump */
};