windows-nt/Source/XPSP1/NT/drivers/video/ms/weitek/mini/vga.c

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2020-09-26 03:20:57 -05:00
/*++
Copyright (c) 1993 Weitek Corporation
Module Name:
vga.c
Abstract:
This module contains VGA specific functions for the Weitek P9
miniport device driver.
Environment:
Kernel mode
Revision History may be found at the end of this file.
--*/
#include "p9.h"
#include "p9gbl.h"
#include "vga.h"
VOID
LockVGARegs(
PHW_DEVICE_EXTENSION HwDeviceExtension
)
/*++
Routine Description:
Arguments:
HwDeviceExtension - Pointer to the miniport driver's device extension.
pPal - Pointer to the array of pallete entries.
StartIndex - Specifies the first pallete entry provided in pPal.
Count - Number of palette entries in pPal
Return Value:
None.
--*/
{
//
// *** Don't lock it for ease of debug ***
//
// VGA_WR_REG(SEQ_INDEX_PORT, SEQ_MISC_INDEX);
// VGA_WR_REG(SEQ_DATA_PORT, VGA_RD_REG(SEQ_DATA_PORT) | SEQ_MISC_CRLOCK);
return;
}
VOID
UnlockVGARegs(
PHW_DEVICE_EXTENSION HwDeviceExtension
)
/*++
Routine Description:
Arguments:
HwDeviceExtension - Pointer to the miniport driver's device extension.
pPal - Pointer to the array of pallete entries.
StartIndex - Specifies the first pallete entry provided in pPal.
Count - Number of palette entries in pPal
Return Value:
None.
--*/
{
USHORT holdit;
VGA_WR_REG(SEQ_INDEX_PORT, SEQ_MISC_INDEX);
holdit = VGA_RD_REG(SEQ_DATA_PORT);
VGA_WR_REG(SEQ_DATA_PORT, holdit);
VGA_WR_REG(SEQ_DATA_PORT, holdit);
holdit = VGA_RD_REG(SEQ_DATA_PORT);
VGA_WR_REG(SEQ_DATA_PORT, holdit & ~(SEQ_MISC_CRLOCK));
return;
}