1 /* $NetBSD: vga_common.c,v 1.7 2006/02/19 15:16:53 jmcneill 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/cdefs.h> 31 __KERNEL_RCSID(0, "$NetBSD: vga_common.c,v 1.7 2006/02/19 15:16:53 jmcneill Exp $"); 32 33 #include <sys/param.h> 34 #include <sys/device.h> 35 #include <machine/bus.h> 36 37 #include <dev/ic/mc6845reg.h> 38 #include <dev/ic/pcdisplayvar.h> 39 #include <dev/ic/vgareg.h> 40 #include <dev/ic/vgavar.h> 41 42 #ifdef __i386__ 43 #include <arch/i386/bios/vesafbvar.h> 44 #endif 45 46 /* 47 * The following functions implement back-end configuration grabbing 48 * and attachment. 49 */ 50 int 51 vga_common_probe(bus_space_tag_t iot, bus_space_tag_t memt) 52 { 53 bus_space_handle_t ioh_vga, ioh_6845, memh; 54 u_int8_t regval; 55 u_int16_t vgadata; 56 int gotio_vga, gotio_6845, gotmem, mono, rv; 57 int dispoffset; 58 #ifdef __i386__ 59 struct device *dv; 60 struct vesafb_softc *vesafb; 61 #endif 62 63 gotio_vga = gotio_6845 = gotmem = rv = 0; 64 65 #ifdef __i386__ 66 for (dv = alldevs.tqh_first; dv; dv=dv->dv_list.tqe_next) 67 if (strncmp(dv->dv_xname, "vesafb", 6) == 0) { 68 vesafb = (struct vesafb_softc *)dv; 69 if (vesafb->sc_isconsole) 70 goto bad; 71 } 72 #endif 73 74 if (bus_space_map(iot, 0x3c0, 0x10, 0, &ioh_vga)) 75 goto bad; 76 gotio_vga = 1; 77 78 /* read "misc output register" */ 79 regval = bus_space_read_1(iot, ioh_vga, VGA_MISC_DATAR); 80 mono = !(regval & 1); 81 82 if (bus_space_map(iot, (mono ? 0x3b0 : 0x3d0), 0x10, 0, &ioh_6845)) 83 goto bad; 84 gotio_6845 = 1; 85 86 if (bus_space_map(memt, 0xa0000, 0x20000, 0, &memh)) 87 goto bad; 88 gotmem = 1; 89 90 dispoffset = (mono ? 0x10000 : 0x18000); 91 92 vgadata = bus_space_read_2(memt, memh, dispoffset); 93 bus_space_write_2(memt, memh, dispoffset, 0xa55a); 94 if (bus_space_read_2(memt, memh, dispoffset) != 0xa55a) 95 goto bad; 96 bus_space_write_2(memt, memh, dispoffset, vgadata); 97 98 /* 99 * check if this is really a VGA 100 * (try to write "Color Select" register as XFree86 does) 101 * XXX check before if at least EGA? 102 */ 103 /* reset state */ 104 (void) bus_space_read_1(iot, ioh_6845, 10); 105 bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX, 106 20 | 0x20); /* colselect | enable */ 107 regval = bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR); 108 /* toggle the implemented bits */ 109 bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval ^ 0x0f); 110 bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX, 20 | 0x20); 111 /* read back */ 112 if (bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR) != (regval ^ 0x0f)) 113 goto bad; 114 /* restore contents */ 115 bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval); 116 117 rv = 1; 118 bad: 119 if (gotio_vga) 120 bus_space_unmap(iot, ioh_vga, 0x10); 121 if (gotio_6845) 122 bus_space_unmap(iot, ioh_6845, 0x10); 123 if (gotmem) 124 bus_space_unmap(memt, memh, 0x20000); 125 126 return (rv); 127 } 128