109 lines
3.1 KiB
C
109 lines
3.1 KiB
C
/* $NetBSD: vga_common.c,v 1.1 2002/10/15 17:30:44 junyoung Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1995, 1996 Carnegie-Mellon University.
|
|
* All rights reserved.
|
|
*
|
|
* Author: Chris G. Demetriou
|
|
*
|
|
* Permission to use, copy, modify and distribute this software and
|
|
* its documentation is hereby granted, provided that both the copyright
|
|
* notice and this permission notice appear in all copies of the
|
|
* software, derivative works or modified versions, and any portions
|
|
* thereof, and that both notices appear in supporting documentation.
|
|
*
|
|
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
|
|
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
|
|
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
|
|
*
|
|
* Carnegie Mellon requests users of this software to return to
|
|
*
|
|
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
|
|
* School of Computer Science
|
|
* Carnegie Mellon University
|
|
* Pittsburgh PA 15213-3890
|
|
*
|
|
* any improvements or extensions that they make and grant Carnegie the
|
|
* rights to redistribute these changes.
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/device.h>
|
|
#include <machine/bus.h>
|
|
|
|
#include <dev/ic/mc6845reg.h>
|
|
#include <dev/ic/pcdisplayvar.h>
|
|
#include <dev/ic/vgareg.h>
|
|
#include <dev/ic/vgavar.h>
|
|
|
|
/*
|
|
* The following functions implement back-end configuration grabbing
|
|
* and attachment.
|
|
*/
|
|
int
|
|
vga_common_probe(bus_space_tag_t iot, bus_space_tag_t memt)
|
|
{
|
|
bus_space_handle_t ioh_vga, ioh_6845, memh;
|
|
u_int8_t regval;
|
|
u_int16_t vgadata;
|
|
int gotio_vga, gotio_6845, gotmem, mono, rv;
|
|
int dispoffset;
|
|
|
|
gotio_vga = gotio_6845 = gotmem = rv = 0;
|
|
|
|
if (bus_space_map(iot, 0x3c0, 0x10, 0, &ioh_vga))
|
|
goto bad;
|
|
gotio_vga = 1;
|
|
|
|
/* read "misc output register" */
|
|
regval = bus_space_read_1(iot, ioh_vga, 0xc);
|
|
mono = !(regval & 1);
|
|
|
|
if (bus_space_map(iot, (mono ? 0x3b0 : 0x3d0), 0x10, 0, &ioh_6845))
|
|
goto bad;
|
|
gotio_6845 = 1;
|
|
|
|
if (bus_space_map(memt, 0xa0000, 0x20000, 0, &memh))
|
|
goto bad;
|
|
gotmem = 1;
|
|
|
|
dispoffset = (mono ? 0x10000 : 0x18000);
|
|
|
|
vgadata = bus_space_read_2(memt, memh, dispoffset);
|
|
bus_space_write_2(memt, memh, dispoffset, 0xa55a);
|
|
if (bus_space_read_2(memt, memh, dispoffset) != 0xa55a)
|
|
goto bad;
|
|
bus_space_write_2(memt, memh, dispoffset, vgadata);
|
|
|
|
/*
|
|
* check if this is really a VGA
|
|
* (try to write "Color Select" register as XFree86 does)
|
|
* XXX check before if at least EGA?
|
|
*/
|
|
/* reset state */
|
|
(void) bus_space_read_1(iot, ioh_6845, 10);
|
|
bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX,
|
|
20 | 0x20); /* colselect | enable */
|
|
regval = bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR);
|
|
/* toggle the implemented bits */
|
|
bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval ^ 0x0f);
|
|
bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX,
|
|
20 | 0x20);
|
|
/* read back */
|
|
if (bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR) != (regval ^ 0x0f))
|
|
goto bad;
|
|
/* restore contents */
|
|
bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval);
|
|
|
|
rv = 1;
|
|
bad:
|
|
if (gotio_vga)
|
|
bus_space_unmap(iot, ioh_vga, 0x10);
|
|
if (gotio_6845)
|
|
bus_space_unmap(iot, ioh_6845, 0x10);
|
|
if (gotmem)
|
|
bus_space_unmap(memt, memh, 0x20000);
|
|
|
|
return (rv);
|
|
}
|