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#include <u.h>
#include <libc.h>
#include <bio.h>
#include "pci.h"
#include "vga.h"
/*
* ATT21C498 16-Bit Interface RAMDAC
* PrecisionDAC Technology
*/
enum {
Cr0 = 0x00, /* Control register 0 */
Midr = 0x01, /* Manufacturer's identification register */
Didr = 0x02, /* Device identification register */
Rtest = 0x03, /* Red signature analysis register */
Gtest = 0x04, /* Green signature analysis register */
Btest = 0x05, /* Blue signature analysis register */
Nir = 0x06, /* number of indirect registers */
};
static void
attdacio(uchar reg)
{
int i;
/*
* Access to the indirect registers is accomplished by reading
* Pixmask 4 times, then subsequent reads cycle through the
* indirect registers. Any I/O write to a direct register resets
* the sequence.
*/
inportb(PaddrW);
for(i = 0; i < 4+reg; i++)
inportb(Pixmask);
}
uchar
attdaci(uchar reg)
{
uchar r;
attdacio(reg);
r = inportb(Pixmask);
inportb(PaddrW);
return r;
}
void
attdaco(uchar reg, uchar data)
{
attdacio(reg);
outportb(Pixmask, data);
inportb(PaddrW);
}
static void
options(Vga*, Ctlr* ctlr)
{
ctlr->flag |= Hpclk2x8|Foptions;
}
static void
init(Vga* vga, Ctlr* ctlr)
{
ulong grade, pclk;
char *p;
/*
* Part comes in -170, -130 and -110MHz speed-grades.
* In 8-bit mode the max. PCLK is 80MHz for the -110 part
* and 110MHz for the others. In 2x8-bit mode, the max.
* PCLK is the speed-grade, using the 2x doubler.
* We can use mode 2 (2x8-bit, internal clock doubler)
* if connected to a suitable graphics chip, e.g. the
* S3 Vision864.
* 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(vga->ctlr && ((vga->ctlr->flag & Hpclk2x8) && vga->mode->z == 8))
pclk = grade;
else{
if(grade == 110000000)
pclk = 80000000;
else
pclk = 110000000;
}
/*
* 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;
/*
* Determine whether to use 2x8-bit mode or not.
* If yes and the clock has already been initialised,
* initialise it again.
*/
if(vga->ctlr && (vga->ctlr->flag & Hpclk2x8) && vga->mode->z == 8 && vga->f[0] > 80000000){
vga->f[0] /= 2;
resyncinit(vga, ctlr, Upclk2x8, 0);
}
if(vga->f[0] > pclk)
error("%s: invalid pclk - %ld\n", ctlr->name, vga->f[0]);
ctlr->flag |= Finit;
}
static void
load(Vga* vga, Ctlr* ctlr)
{
uchar mode, x;
/*
* Put the chip to sleep.
*/
x = attdaci(Cr0);
attdaco(Cr0, x|0x04);
mode = 0x00;
if(ctlr->flag & Upclk2x8)
mode = 0x20;
/*
* Set the mode in the RAMDAC, setting 6/8-bit colour
* as appropriate and waking the chip back up.
*/
if(vga->mode->z == 8 && 0)
mode |= 0x02;
attdaco(Cr0, mode);
ctlr->flag |= Fload;
}
static void
dump(Vga*, Ctlr* ctlr)
{
int i;
printitem(ctlr->name, "");
for(i = 0; i < Nir; i++)
printreg(attdaci(i));
}
Ctlr att21c498 = {
"att21c498", /* name */
0, /* snarf */
options, /* options */
init, /* init */
load, /* load */
dump, /* dump */
};
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