1 /* $NetBSD: vga_common.c,v 1.1 2002/10/15 17:30:44 junyoung Exp $ */ 2 3 /* 4 * Copyright (c) 1995, 1996 Carnegie-Mellon University. 5 * All rights reserved. 6 * 7 * Author: Chris G. Demetriou 8 * 9 * Permission to use, copy, modify and distribute this software and 10 * its documentation is hereby granted, provided that both the copyright 11 * notice and this permission notice appear in all copies of the 12 * software, derivative works or modified versions, and any portions 13 * thereof, and that both notices appear in supporting documentation. 14 * 15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 16 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 17 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 18 * 19 * Carnegie Mellon requests users of this software to return to 20 * 21 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 22 * School of Computer Science 23 * Carnegie Mellon University 24 * Pittsburgh PA 15213-3890 25 * 26 * any improvements or extensions that they make and grant Carnegie the 27 * rights to redistribute these changes. 28 */ 29 30 #include <sys/param.h> 31 #include <sys/device.h> 32 #include <machine/bus.h> 33 34 #include <dev/ic/mc6845reg.h> 35 #include <dev/ic/pcdisplayvar.h> 36 #include <dev/ic/vgareg.h> 37 #include <dev/ic/vgavar.h> 38 39 /* 40 * The following functions implement back-end configuration grabbing 41 * and attachment. 42 */ 43 int 44 vga_common_probe(bus_space_tag_t iot, bus_space_tag_t memt) 45 { 46 bus_space_handle_t ioh_vga, ioh_6845, memh; 47 u_int8_t regval; 48 u_int16_t vgadata; 49 int gotio_vga, gotio_6845, gotmem, mono, rv; 50 int dispoffset; 51 52 gotio_vga = gotio_6845 = gotmem = rv = 0; 53 54 if (bus_space_map(iot, 0x3c0, 0x10, 0, &ioh_vga)) 55 goto bad; 56 gotio_vga = 1; 57 58 /* read "misc output register" */ 59 regval = bus_space_read_1(iot, ioh_vga, 0xc); 60 mono = !(regval & 1); 61 62 if (bus_space_map(iot, (mono ? 0x3b0 : 0x3d0), 0x10, 0, &ioh_6845)) 63 goto bad; 64 gotio_6845 = 1; 65 66 if (bus_space_map(memt, 0xa0000, 0x20000, 0, &memh)) 67 goto bad; 68 gotmem = 1; 69 70 dispoffset = (mono ? 0x10000 : 0x18000); 71 72 vgadata = bus_space_read_2(memt, memh, dispoffset); 73 bus_space_write_2(memt, memh, dispoffset, 0xa55a); 74 if (bus_space_read_2(memt, memh, dispoffset) != 0xa55a) 75 goto bad; 76 bus_space_write_2(memt, memh, dispoffset, vgadata); 77 78 /* 79 * check if this is really a VGA 80 * (try to write "Color Select" register as XFree86 does) 81 * XXX check before if at least EGA? 82 */ 83 /* reset state */ 84 (void) bus_space_read_1(iot, ioh_6845, 10); 85 bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX, 86 20 | 0x20); /* colselect | enable */ 87 regval = bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR); 88 /* toggle the implemented bits */ 89 bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval ^ 0x0f); 90 bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX, 91 20 | 0x20); 92 /* read back */ 93 if (bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR) != (regval ^ 0x0f)) 94 goto bad; 95 /* restore contents */ 96 bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval); 97 98 rv = 1; 99 bad: 100 if (gotio_vga) 101 bus_space_unmap(iot, ioh_vga, 0x10); 102 if (gotio_6845) 103 bus_space_unmap(iot, ioh_6845, 0x10); 104 if (gotmem) 105 bus_space_unmap(memt, memh, 0x20000); 106 107 return (rv); 108 } 109