#define ATI68830_DAC    0
#define SIERRA_DAC      2
#define TI_DAC          4
#define BROOKTREE_DAC   6
#define ATT_DAC         8
#define INPUT_CLK_SEL	0x2ed
#define OUTPUT_CLK_SEL	0x2ea
#define MUX_CNTL        0x2eb
#define HORIZONTAL_OVERSCAN     0x62EE
#define ATT_MODE_CNTL   0x2ea
#define LOCAL_CNTL      0x32ee
#define NUM_ROM_BASE_RANGES 2


/*
;----------------------------------------------------------------------
; UNINIT_TI_DAC
;   Prepare DAC for 8514/A compatible mode
;----------------------------------------------------------------------
*/


void Uninit_ti_dac ()
{

    passth_8514(OFF);       // can only program DAC in 8514 mode

    switch (INP(CONFIG_STATUS_1+1)&0xe)
        {
        case TI_DAC:

            /* set EXT_DAC_ADDR field */

	    OUTPW (EXT_GE_CONFIG,0x201a);

	    /* INPut clock source is CLK0 */

	    OUTP (INPUT_CLK_SEL,0);

	    /* OUTPut clock is SCLK/1 and VCLK/1 */

	    OUTP (OUTPUT_CLK_SEL,0);

            /* set MUX CONTROL TO 8/16 */
            
	    OUTP (MUX_CNTL,0x1d);

            /* set default 8bpp pixel delay and blank adjust */


	    OUTPW (LOCAL_CNTL,INPW(LOCAL_CNTL) | 8);	// TI_DAC_BLANK_ADJUST is always on

            Set_blank_adj(0xc);

            /* set horizontal skew */

	    OUTP (HORIZONTAL_OVERSCAN,1);
            break;


        case ATT_DAC:

	    OUTPW(EXT_GE_CONFIG,0x101a);
	    OUTP(ATT_MODE_CNTL,0);


        default:           
            /* PIXEL_DELAY=0 */

            Set_blank_adj(0);
    
            /* set horizontal skew */

	    OUTPW(HORIZONTAL_OVERSCAN,0);
            break;
        }

//
// reset EXT_DAC_ADDR, put DAC in 6 bit mode, engine in 8 bit mode
//
    OUTPW(EXT_GE_CONFIG,0x1a);
    passth_8514(ON);
}


/*
;----------------------------------------------------------------------
; SET_BLANK_ADJ
;   Sets the blank adjust and pixel delay values
;   INPUT: blank adjust and pixel delay
;----------------------------------------------------------------------
*/


void Set_blank_adj(BYTE adjust)
{
BYTE misc;

    misc=INP(R_MISC_CNTL+1) & 0xf0 | adjust;

    OUTP(MISC_CNTL+1,misc);

}



/************************************************************************
 * passth_8514()
 *   Turn passthrough off (8514 mode) or on (vga passthrough)
 *   Note that this routine is specific to ATI graphics accelerators.
 *   Generic 8514/A routine should also include setting up CRT parameters
 *   to ensure that the DAC gets a reasonable clock rate.
 ************************************************************************/

void passth_8514(int status)
	{
	OUTP(DISP_CNTL,0x53);		/* disable CRT controller */

	if (status == OFF)
            {
	    OUTPW(ADVFUNC_CNTL,0x7);
	    OUTPW(CLOCK_SEL,INPW(CLOCK_SEL)|1);        /* slow down the clock rate */
            }
	else
            {
	    OUTPW(ADVFUNC_CNTL,0x6);
	    OUTPW(CLOCK_SEL,INPW(CLOCK_SEL)&0xfffe);	/* speed up the clock rate */
            }
	OUTP(DISP_CNTL,0x33);		/* enable CRT controller */
	}