Leaked source code of windows server 2003
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180 lines
4.2 KiB

/*++
Copyright (c) 1994-1995 International Buisness Machines Corporation
Copyright (c) 1994-1995 Microsoft Corporation
Module Name:
sdac.c
Abstract:
This module contains the code that initializes the S3 SDAC.
Environment:
Kernel mode
Revision History:
--*/
#include "s3.h"
#if defined(ALLOC_PRAGMA)
#pragma alloc_text(PAGE,InitializeSDAC)
#pragma alloc_text(PAGE,FindSDAC)
#endif
BOOLEAN
InitializeSDAC( PHW_DEVICE_EXTENSION HwDeviceExtension )
/*++
Routine Description:
Initializes the SDAC.
Arguments:
HwDeviceExtension - Supplies a pointer to the miniport's device extension.
Return Value:
Always TRUE
--*/
{
SDAC_PLL_PARMS
*SdacClk0;
ULONG
tablebase;
UCHAR
i,
clk,
dval,
old55;
tablebase = HwDeviceExtension->ActiveFrequencyEntry->Fixed.Clock;
clk = (UCHAR) tablebase;
tablebase = (tablebase < 8) ? 0 : ((tablebase - 2) / 6) * 6;
SdacClk0 = &SdacTable[tablebase];
clk -= (UCHAR) tablebase;
clk |= 0x20;
// set RS[2] with CR55[0];
VideoPortWritePortUchar(CRT_ADDRESS_REG, 0x55);
dval = VideoPortReadPortUchar(CRT_DATA_REG);
old55 = dval;
dval &= 0xfc;
dval |= 0x01;
VideoPortWritePortUchar(CRT_DATA_REG, dval);
VideoPortReadPortUchar(CRT_DATA_REG);
// Enhanced Command Register
if( HwDeviceExtension->ActiveFrequencyEntry->BitsPerPel == 16 )
VideoPortWritePortUchar(DAC_PIXEL_MASK_REG, 0x50);
else
VideoPortWritePortUchar(DAC_PIXEL_MASK_REG, 0x00);
// Program CLK0 registers
for( i = 2; i < 8; ++i ) // write registers f2 - f7 only
{
// make sure we don't run off the end of the table
if( (ULONG_PTR) &SdacClk0[i] >= (ULONG_PTR) &SdacTable[SDAC_TABLE_SIZE] )
break;
if( SdacClk0[i].m || SdacClk0[i].n )
{
VideoPortWritePortUchar(DAC_ADDRESS_WRITE_PORT, i);
VideoPortWritePortUchar(DAC_DATA_REG_PORT, SdacClk0[i].m);
VideoPortWritePortUchar(DAC_DATA_REG_PORT, SdacClk0[i].n);
}
}
// Program CLK1
VideoPortWritePortUchar(DAC_ADDRESS_WRITE_PORT, 0x0a);
VideoPortWritePortUchar(DAC_DATA_REG_PORT, 0x41);
VideoPortWritePortUchar(DAC_DATA_REG_PORT, 0x26);
// select CLK0 with the PLL control register
VideoPortWritePortUchar(DAC_ADDRESS_WRITE_PORT, 0x0e);
VideoPortWritePortUchar(DAC_DATA_REG_PORT, clk);
// restore CR55
VideoPortWritePortUchar(CRT_ADDRESS_REG, 0x55);
VideoPortWritePortUchar(CRT_DATA_REG, old55);
return( TRUE );
}
BOOLEAN
FindSDAC( PHW_DEVICE_EXTENSION HwDeviceExtension )
/*++
Routine Description:
Detects and S3 SDAC.
Arguments:
HwDeviceExtension - Supplies a pointer to the miniport's device extension.
Return Value:
TRUE if SDAC detected; FALSE if not.
--*/
{
UCHAR
regval,
old55;
// 4 consecutive reads of the SDAC's Pixel Mask Register cause
// the next access to that register to be redirected to the
// SDAC's Enhanced Command Register, additionally the 4th read
// returns 0x70 to identify the SDAC
// set CR55[0] to access the Pixel Mask Register
VideoPortWritePortUchar( CRT_ADDRESS_REG, 0x55 );
old55 = VideoPortReadPortUchar( CRT_DATA_REG );
VideoPortWritePortUchar( CRT_DATA_REG, (UCHAR) (old55 & 0xfc) );
// look for the SDAC's ID
VideoPortWritePortUchar( DAC_PIXEL_MASK_REG, 0 );
VideoPortWritePortUchar( DAC_PIXEL_MASK_REG, 0xff );
VideoPortReadPortUchar( DAC_PIXEL_MASK_REG );
VideoPortReadPortUchar( DAC_PIXEL_MASK_REG );
VideoPortReadPortUchar( DAC_PIXEL_MASK_REG );
regval = VideoPortReadPortUchar( DAC_PIXEL_MASK_REG );
if( (regval & 0xf0) == 0x70 )
{
// clear the redirection
VideoPortReadPortUchar( DAC_PIXEL_MASK_REG );
return( TRUE );
}
// restore the contents of register 55
VideoPortWritePortUchar( CRT_ADDRESS_REG, 0x55 );
VideoPortWritePortUchar( CRT_DATA_REG, old55 );
return( FALSE );
}