111 lines
3.2 KiB
C
111 lines
3.2 KiB
C
/* $NetBSD: vga_common.c,v 1.11 2009/02/19 00:39:26 jmcneill Exp $ */
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/*
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* Copyright (c) 1995, 1996 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Author: Chris G. Demetriou
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: vga_common.c,v 1.11 2009/02/19 00:39:26 jmcneill Exp $");
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#include <sys/param.h>
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#include <sys/device.h>
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#include <sys/bus.h>
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#include <dev/ic/mc6845reg.h>
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#include <dev/ic/pcdisplayvar.h>
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#include <dev/ic/vgareg.h>
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#include <dev/ic/vgavar.h>
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/*
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* The following functions implement back-end configuration grabbing
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* and attachment.
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*/
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int
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vga_common_probe(bus_space_tag_t iot, bus_space_tag_t memt)
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{
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bus_space_handle_t ioh_vga, ioh_6845, memh;
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u_int8_t regval;
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u_int16_t vgadata;
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int gotio_vga, gotio_6845, gotmem, mono, rv;
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int dispoffset;
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gotio_vga = gotio_6845 = gotmem = rv = 0;
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if (bus_space_map(iot, 0x3c0, 0x10, 0, &ioh_vga))
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goto bad;
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gotio_vga = 1;
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/* read "misc output register" */
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regval = bus_space_read_1(iot, ioh_vga, VGA_MISC_DATAR);
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mono = !(regval & 1);
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if (bus_space_map(iot, (mono ? 0x3b0 : 0x3d0), 0x10, 0, &ioh_6845))
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goto bad;
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gotio_6845 = 1;
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if (bus_space_map(memt, 0xa0000, 0x20000, 0, &memh))
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goto bad;
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gotmem = 1;
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dispoffset = (mono ? 0x10000 : 0x18000);
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vgadata = bus_space_read_2(memt, memh, dispoffset);
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bus_space_write_2(memt, memh, dispoffset, 0xa55a);
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if (bus_space_read_2(memt, memh, dispoffset) != 0xa55a)
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goto bad;
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bus_space_write_2(memt, memh, dispoffset, vgadata);
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/*
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* check if this is really a VGA
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* (try to write "Color Select" register as XFree86 does)
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* XXX check before if at least EGA?
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*/
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/* reset state */
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(void) bus_space_read_1(iot, ioh_6845, 10);
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bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX,
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20 | 0x20); /* colselect | enable */
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regval = bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR);
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/* toggle the implemented bits */
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bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval ^ 0x0f);
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bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX, 20 | 0x20);
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/* read back */
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if (bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR) != (regval ^ 0x0f))
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goto bad;
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/* restore contents */
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bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval);
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rv = 1;
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bad:
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if (gotio_vga)
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bus_space_unmap(iot, ioh_vga, 0x10);
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if (gotio_6845)
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bus_space_unmap(iot, ioh_6845, 0x10);
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if (gotmem)
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bus_space_unmap(memt, memh, 0x20000);
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return (rv);
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}
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