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/*
* btdacs.c:
*
* RAMDAC definition for Bt485
*
* NON-FUNCTIONAL
*/
#include <stdlib.h>
#include <stdio.h>
#include "libvga.h"
#include "timing.h"
#include "vgaregs.h"
#include "driver.h" /* for __svgalib_driver_report */
#include "ramdac.h"
/*
* RAMDAC definition for industry-standard AT&T20C498 DAC with 16-bit
* pixel port, and compatibles.
* Differently rated versions exist, such as 80, 110, 135 and 170 MHz.
* This code assumes the DAC is actually connected with a 16-bit path.
* (an example of a 498-compatible DAC being used with a 8-bit path
* is the Hercules Stingray Pro/V with the IC Works ZoomDAC).
*/
#ifdef INCLUDE_BT485_DAC_TEST
static int bt485_probe(void)
{
return 0;
}
#else
#define bt485_probe 0
#endif
#ifdef INCLUDE_BT485_DAC
static void bt485_init(void)
{
if (__svgalib_driver_report)
cprintf("svgalib: Using BT485 DAC, 135 MHz rated.\n");
}
static int bt485_map_clock(int bpp, int pixelclock)
{
return pixelclock;
if (bpp == 8 && pixelclock > 80000)
/* Use 16-bit path, clock doubling at RAMDAC. */
return pixelclock / 2;
if (bpp == 16)
return pixelclock;
if (bpp == 32)
return pixelclock * 2;
return pixelclock;
}
static int bt485_map_horizontal_crtc(int bpp, int pixelclock, int htiming)
{
return htiming
/* Not sure. */
if (bpp == 8 && pixelclock > 80000)
/* Use 16-bit path, clock doubling at RAMDAC. */
return htiming / 2;
if (bpp == 32)
return htiming * 2;
return htiming;
}
static void bt485_initializestate(unsigned char *regs, int bpp, int colormode,
int pixelclock)
{
regs[0] = 0;
if (colormode == CLUT8_8)
regs[0] = 0x02;
if (colormode == RGB16_555)
regs[0] = 0x10;
if (colormode == RGB16_565)
regs[0] = 0x30;
if (colormode == RGB32_888_B)
regs[0] = 0x50;
}
static void 485_qualify_cardspecs(CardSpecs * cardspecs, int dacspeed)
{
dacspeed = __svgalib_setDacSpeed(dacspeed, 135000);
cardspecs->maxPixelClock4bpp = 0;
cardspecs->maxPixelClock8bpp = dacspeed;
cardspecs->maxPixelClock16bpp = dacspeed;
cardspecs->maxPixelClock24bpp = 0;
cardspecs->maxPixelClock32bpp = dacspeed ;
cardspecs->mapClock = bt485_map_clock;
cardspecs->mapHorizontalCrtc = att20c498_map_horizontal_crtc;
}
DacMethods __svgalib_BT485_methods =
{
BT485,
"BT485 DAC",
0,
bt485_probe,
bt485_init,
bt485_qualify_cardspecs,
__svgalib_Sierra_32K_savestate,
__svgalib_Sierra_32K_restorestate,
bt485_initializestate,
1 /* State size. */
};
#endif