ref: 02d09919941c8f33f93f9e643a2aebb1fea14a91
dir: /sys/src/cmd/aux/vga/edid.c/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <ndb.h>
#include "pci.h"
#include "vga.h"
static void
addmode(Modelist **l, Mode m)
{
Modelist *ll;
int rr;
rr = (m.frequency+m.ht*m.vt/2)/(m.ht*m.vt);
snprint(m.name, sizeof m.name, "%dx%d@%dHz", m.x, m.y, rr);
for(ll = *l; ll != nil; ll = *l){
if(strcmp(ll->name, m.name) == 0)
return;
l = &ll->next;
}
ll = alloc(sizeof(Modelist));
ll->Mode = m;
*l = ll;
}
/*
* Parse VESA EDID information. Based on the VESA
* Extended Display Identification Data standard, Version 3,
* November 13, 1997. See /public/doc/vesa/edidv3.pdf.
*
* This only handles 128-byte EDID blocks. Until I find
* a monitor that produces 256-byte blocks, I'm not going
* to try to decode them.
*/
/*
* Established timings block. There is a bitmap
* that says whether each mode is supported. Most
* of these have VESA definitions. Those that don't are marked
* as such, and we ignore them (the lookup fails).
*/
static char *estabtime[] = {
"720x400@70Hz", /* non-VESA: IBM, VGA */
"720x400@88Hz", /* non-VESA: IBM, XGA2 */
"640x480@60Hz",
"640x480@67Hz", /* non-VESA: Apple, Mac II */
"640x480@72Hz",
"640x480@75Hz",
"800x600@56Hz",
"800x600@60Hz",
"800x600@72Hz",
"800x600@75Hz",
"832x624@75Hz", /* non-VESA: Apple, Mac II */
"1024x768i@87Hz", /* non-VESA: IBM */
"1024x768@60Hz",
"1024x768@70Hz",
"1024x768@75Hz",
"1280x1024@75Hz",
"1152x870@75Hz", /* non-VESA: Apple, Mac II */
};
/*
* Decode the EDID detailed timing block. See pp. 20-21 of the standard.
*/
static int
decodedtb(Mode *m, uchar *p)
{
int ha, hb, hso, hspw, rr, va, vb, vso, vspw;
/* int hbord, vbord, dxmm, dymm, hbord, vbord; */
memset(m, 0, sizeof *m);
m->frequency = ((p[1]<<8) | p[0]) * 10000;
ha = ((p[4] & 0xF0)<<4) | p[2]; /* horizontal active */
hb = ((p[4] & 0x0F)<<8) | p[3]; /* horizontal blanking */
va = ((p[7] & 0xF0)<<4) | p[5]; /* vertical active */
vb = ((p[7] & 0x0F)<<8) | p[6]; /* vertical blanking */
hso = ((p[11] & 0xC0)<<2) | p[8]; /* horizontal sync offset */
hspw = ((p[11] & 0x30)<<4) | p[9]; /* horizontal sync pulse width */
vso = ((p[11] & 0x0C)<<2) | ((p[10] & 0xF0)>>4); /* vertical sync offset */
vspw = ((p[11] & 0x03)<<4) | (p[10] & 0x0F); /* vertical sync pulse width */
/* dxmm = (p[14] & 0xF0)<<4) | p[12]; /* horizontal image size (mm) */
/* dymm = (p[14] & 0x0F)<<8) | p[13]; /* vertical image size (mm) */
/* hbord = p[15]; /* horizontal border (pixels) */
/* vbord = p[16]; /* vertical border (pixels) */
m->x = ha;
m->y = va;
m->ht = ha+hb;
m->shb = ha+hso;
m->ehb = ha+hso+hspw;
m->vt = va+vb;
m->vrs = va+vso;
m->vre = va+vso+vspw;
if(p[17] & 0x80) /* interlaced */
m->interlace = 'v';
if(p[17] & 0x60) /* some form of stereo monitor mode; no support */
return -1;
/*
* Sync signal description. I have no idea how to properly handle the
* first three cases, which I think are aimed at things other than
* canonical SVGA monitors.
*/
switch((p[17] & 0x18)>>3) {
case 0: /* analog composite sync signal*/
case 1: /* bipolar analog composite sync signal */
/* p[17] & 0x04 means serration: hsync during vsync */
/* p[17] & 0x02 means sync pulse appears on RGB not just G */
break;
case 2: /* digital composite sync signal */
/* p[17] & 0x04 means serration: hsync during vsync */
/* p[17] & 0x02 means hsync positive outside vsync */
break;
case 3: /* digital separate sync signal; the norm */
m->vsync = (p[17] & 0x04) ? '+' : '-';
m->hsync = (p[17] & 0x02) ? '+' : '-';
break;
}
/* p[17] & 0x01 is another stereo bit, only referenced if p[17] & 0x60 != 0 */
rr = (m->frequency+m->ht*m->vt/2) / (m->ht*m->vt);
snprint(m->name, sizeof m->name, "%dx%d@%dHz", m->x, m->y, rr);
return 0;
}
static int
vesalookup(Mode *m, char *name)
{
Mode **p;
for(p=vesamodes; *p; p++)
if(strcmp((*p)->name, name) == 0) {
*m = **p;
return 0;
}
return -1;
}
static int
decodesti(Mode *m, uchar *p)
{
int x, y, rr;
char str[20];
x = (p[0]+31)*8;
switch((p[1]>>6) & 3){
default:
case 0:
y = x;
break;
case 1:
y = (x*4)/3;
break;
case 2:
y = (x*5)/4;
break;
case 3:
y = (x*16)/9;
break;
}
rr = (p[1] & 0x1F) + 60;
sprint(str, "%dx%d@%dHz", x, y, rr);
return vesalookup(m, str);
}
Edid*
parseedid128(void *v)
{
static uchar magic[8] = { 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00 };
uchar *p, *q, sum;
int dpms, estab, i, m, vid;
Mode mode;
Edid *e;
e = alloc(sizeof(Edid));
p = (uchar*)v;
if(memcmp(p, magic, 8) != 0) {
free(e);
werrstr("bad edid header");
return nil;
}
sum = 0;
for(i=0; i<128; i++)
sum += p[i];
if(sum != 0) {
free(e);
werrstr("bad edid checksum");
return nil;
}
p += 8;
assert(p == (uchar*)v+8); /* assertion offsets from pp. 12-13 of the standard */
/*
* Manufacturer name is three 5-bit ascii letters, packed
* into a big endian [sic] short in big endian order. The high bit is unused.
*/
i = (p[0]<<8) | p[1];
p += 2;
e->mfr[0] = 'A'-1 + ((i>>10) & 0x1F);
e->mfr[1] = 'A'-1 + ((i>>5) & 0x1F);
e->mfr[2] = 'A'-1 + (i & 0x1F);
e->mfr[3] = '\0';
/*
* Product code is a little endian short.
*/
e->product = (p[1]<<8) | p[0];
p += 2;
/*
* Serial number is a little endian long, 0x01010101 = unused.
*/
e->serial = (p[3]<<24) | (p[2]<<16) | (p[1]<<8) | p[0];
p += 4;
if(e->serial == 0x01010101)
e->serial = 0;
e->mfrweek = *p++;
e->mfryear = 1990 + *p++;
assert(p == (uchar*)v+8+10);
/*
* Structure version is next two bytes: major.minor.
*/
e->version = *p++;
e->revision = *p++;
assert(p == (uchar*)v+8+10+2);
/*
* Basic display parameters / features.
*/
/*
* Video input definition byte: 0x80 tells whether it is
* an analog or digital screen; we ignore the other bits.
* See p. 15 of the standard.
*/
vid = *p++;
if(vid & 0x80)
e->flags |= Fdigital;
e->dxcm = *p++;
e->dycm = *p++;
e->gamma = 100 + *p++;
dpms = *p++;
if(dpms & 0x80)
e->flags |= Fdpmsstandby;
if(dpms & 0x40)
e->flags |= Fdpmssuspend;
if(dpms & 0x20)
e->flags |= Fdpmsactiveoff;
if((dpms & 0x18) == 0x00)
e->flags |= Fmonochrome;
if(dpms & 0x01)
e->flags |= Fgtf;
assert(p == (uchar*)v+8+10+2+5);
/*
* Color characteristics currently ignored.
*/
p += 10;
assert(p == (uchar*)v+8+10+2+5+10);
/*
* Timing information priority order (EDID 1.3 section 5)
* 1. Preferred Timing Mode (first detailed timing block)
* 2. Other Detailed Timing Mode, in order listed
* 3. Standard Timings, in order listed
* 4. Established Timings
*/
/*
* Detailed Timings
*/
p = (uchar*)v+8+10+2+5+10+3+16;
for(i=0; i<4; i++, p+=18)
if(p[0] || p[1]) /* detailed timing block: p[0] or p[1] != 0 */
if(decodedtb(&mode, p) == 0)
addmode(&e->modelist, mode);
assert(p == (uchar*)v+8+10+2+5+10+3+16+72);
/*
* Standard Timing Identifications: eight 2-byte selectors
* of more standard timings.
*/
p = (uchar*)v+8+10+2+5+10+3;
for(i=0; i<8; i++, p+=2)
if(decodesti(&mode, p+2*i) == 0)
addmode(&e->modelist, mode);
assert(p == (uchar*)v+8+10+2+5+10+3+16);
p = (uchar*)v+8+10+2+5+10+3+16;
for(i=0; i<4; i++, p+=18){
if(p[0] || p[1])
continue;
/* monitor descriptor block */
switch(p[3]) {
case 0xFF: /* monitor serial number (13-byte ascii, 0A terminated) */
if(q = memchr(p+5, 0x0A, 13))
*q = '\0';
memset(e->serialstr, 0, sizeof(e->serialstr));
strncpy(e->serialstr, (char*)p+5, 13);
break;
case 0xFE: /* ascii string (13-byte ascii, 0A terminated) */
break;
case 0xFD: /* monitor range limits */
e->rrmin = p[5];
e->rrmax = p[6];
e->hrmin = p[7]*1000;
e->hrmax = p[8]*1000;
if(p[9] != 0xFF)
e->pclkmax = p[9]*10*1000000;
break;
case 0xFC: /* monitor name (13-byte ascii, 0A terminated) */
if(q = memchr(p+5, 0x0A, 13))
*q = '\0';
memset(e->name, 0, sizeof(e->name));
strncpy(e->name, (char*)p+5, 13);
break;
case 0xFB: /* extra color point data */
break;
case 0xFA: /* extra standard timing identifications */
for(i=0; i<6; i++)
if(decodesti(&mode, p+5+2*i) == 0)
addmode(&e->modelist, mode);
break;
}
}
assert(p == (uchar*)v+8+10+2+5+10+3+16+72);
/*
* Established timings: a bitmask of 19 preset timings.
*/
p = (uchar*)v+8+10+2+5+10;
estab = (p[0]<<16) | (p[1]<<8) | p[2];
p += 3;
for(i=0, m=1<<23; i<nelem(estabtime); i++, m>>=1)
if(estab & m)
if(vesalookup(&mode, estabtime[i]) == 0)
addmode(&e->modelist, mode);
assert(p == (uchar*)v+8+10+2+5+10+3);
return e;
}
Flag edidflags[] = {
Fdigital, "digital",
Fdpmsstandby, "standby",
Fdpmssuspend, "suspend",
Fdpmsactiveoff, "activeoff",
Fmonochrome, "monochrome",
Fgtf, "gtf",
0
};
void
printflags(Flag *f, int b)
{
int i;
for(i=0; f[i].bit; i++)
if(f[i].bit & b)
Bprint(&stdout, " %s", f[i].desc);
Bprint(&stdout, "\n");
}
void
printedid(Edid *e)
{
Modelist *l;
printitem("edid", "mfr");
Bprint(&stdout, "%s\n", e->mfr);
printitem("edid", "serialstr");
Bprint(&stdout, "%s\n", e->serialstr);
printitem("edid", "name");
Bprint(&stdout, "%s\n", e->name);
printitem("edid", "product");
Bprint(&stdout, "%d\n", e->product);
printitem("edid", "serial");
Bprint(&stdout, "%lud\n", e->serial);
printitem("edid", "version");
Bprint(&stdout, "%d.%d\n", e->version, e->revision);
printitem("edid", "mfrdate");
Bprint(&stdout, "%d.%d\n", e->mfryear, e->mfrweek);
printitem("edid", "size (cm)");
Bprint(&stdout, "%dx%d\n", e->dxcm, e->dycm);
printitem("edid", "gamma");
Bprint(&stdout, "%.2f\n", e->gamma/100.);
printitem("edid", "vert (Hz)");
Bprint(&stdout, "%d-%d\n", e->rrmin, e->rrmax);
printitem("edid", "horz (Hz)");
Bprint(&stdout, "%d-%d\n", e->hrmin, e->hrmax);
printitem("edid", "pclkmax");
Bprint(&stdout, "%lud\n", e->pclkmax);
printitem("edid", "flags");
printflags(edidflags, e->flags);
for(l=e->modelist; l; l=l->next){
printitem("edid", l->name);
Bprint(&stdout, "\n\t\tclock=%g\n", l->frequency/1.e6);
Bprint(&stdout, "\t\tshb=%d ehb=%d ht=%d\n", l->shb, l->ehb, l->ht);
Bprint(&stdout, "\t\tvrs=%d vre=%d vt=%d\n", l->vrs, l->vre, l->vt);
Bprint(&stdout, "\t\thsync=%c vsync=%c %s\n",
l->hsync?l->hsync:'?',
l->vsync?l->vsync:'?',
l->interlace?"interlace=v" : "");
}
}