ref: 17ebe55031ae6945ad1f671b69267a672328e4b1
dir: /sys/src/cmd/aux/vga/ch9294.c/
/* * Chrontel * CH9294 Dual Enhanced Graphics Clock Generator. */ #include <u.h> #include <libc.h> #include <bio.h> #include "pci.h" #include "vga.h" typedef struct { char* name[2]; ulong frequency[16]; } Pattern; static Pattern patterns[] = { { "e", "E", /* Tseng */ 50350000, 56644000, 65000000, 72000000, 80000000, 89800000, 63000000, 75000000, VgaFreq0, VgaFreq1, 31500000, 36000000, 40000000, 44900000, 50000000, 65000000, }, { "g", "G", /* S3, IIT */ VgaFreq0, VgaFreq1, 40000000, 72000000, 50000000, 77000000, 36000000, 44900000, 130000000, 120000000, 80000000, 31500000, 110000000, 65000000, 75000000, 94500000, }, { "k", "K", /* Avance Logic */ 50350000, 56644000, 89800000, 72000000, 75000000, 65000000, 63000000, 80000000, 57272000, 85000000, 94000000, 96000000, 100000000, 108000000, 110000000, 77000000, }, { 0, }, }; static void init(Vga* vga, Ctlr* ctlr) { Pattern *pattern; char *p; int f, fmin, index, divisor, maxdivisor; if(ctlr->flag & Finit) return; if(vga->f[0] == 0) vga->f[0] = vga->mode->frequency; if((p = strchr(ctlr->name, '-')) == 0) error("%s: unknown pattern\n", ctlr->name); p++; for(pattern = patterns; pattern->name[0]; pattern++){ if(strcmp(pattern->name[0], p) == 0) break; if(pattern->name[1] && strcmp(pattern->name[1], p) == 0) break; } if(pattern->name[0] == 0) error("%s: unknown pattern\n", ctlr->name); maxdivisor = 1; if(vga->ctlr && (vga->ctlr->flag & Hclkdiv)) maxdivisor = 8; fmin = vga->f[0]; for(index = 0; index < 16; index++){ for(divisor = 1; divisor <= maxdivisor; divisor <<= 1){ f = vga->f[0] - pattern->frequency[index]/divisor; if(f < 0) f = -f; if(f < fmin){ /*vga->f = pattern->frequency[index];*/ fmin = f; vga->d[0] = divisor; vga->i[0] = index; } } } if(fmin > (vga->f[0]*5)/100) error("%s: can't find frequency %ld\n", ctlr->name, vga->f[0]); ctlr->flag |= Finit; } Ctlr ch9294 = { "ch9294", /* name */ 0, /* snarf */ 0, /* options */ init, /* init */ 0, /* load */ 0, /* dump */ };