| 1 | /* $NetBSD: vga_common.c,v 1.11 2009/02/19 00:39:26 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 1.11 2009/02/19 00:39:26 jmcneill Exp $" ); |
| 32 | |
| 33 | #include <sys/param.h> |
| 34 | #include <sys/device.h> |
| 35 | #include <sys/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 | /* |
| 43 | * The following functions implement back-end configuration grabbing |
| 44 | * and attachment. |
| 45 | */ |
| 46 | int |
| 47 | vga_common_probe(bus_space_tag_t iot, bus_space_tag_t memt) |
| 48 | { |
| 49 | bus_space_handle_t ioh_vga, ioh_6845, memh; |
| 50 | u_int8_t regval; |
| 51 | u_int16_t vgadata; |
| 52 | int gotio_vga, gotio_6845, gotmem, mono, rv; |
| 53 | int dispoffset; |
| 54 | |
| 55 | gotio_vga = gotio_6845 = gotmem = rv = 0; |
| 56 | |
| 57 | if (bus_space_map(iot, 0x3c0, 0x10, 0, &ioh_vga)) |
| 58 | goto bad; |
| 59 | gotio_vga = 1; |
| 60 | |
| 61 | /* read "misc output register" */ |
| 62 | regval = bus_space_read_1(iot, ioh_vga, VGA_MISC_DATAR); |
| 63 | mono = !(regval & 1); |
| 64 | |
| 65 | if (bus_space_map(iot, (mono ? 0x3b0 : 0x3d0), 0x10, 0, &ioh_6845)) |
| 66 | goto bad; |
| 67 | gotio_6845 = 1; |
| 68 | |
| 69 | if (bus_space_map(memt, 0xa0000, 0x20000, 0, &memh)) |
| 70 | goto bad; |
| 71 | gotmem = 1; |
| 72 | |
| 73 | dispoffset = (mono ? 0x10000 : 0x18000); |
| 74 | |
| 75 | vgadata = bus_space_read_2(memt, memh, dispoffset); |
| 76 | bus_space_write_2(memt, memh, dispoffset, 0xa55a); |
| 77 | if (bus_space_read_2(memt, memh, dispoffset) != 0xa55a) |
| 78 | goto bad; |
| 79 | bus_space_write_2(memt, memh, dispoffset, vgadata); |
| 80 | |
| 81 | /* |
| 82 | * check if this is really a VGA |
| 83 | * (try to write "Color Select" register as XFree86 does) |
| 84 | * XXX check before if at least EGA? |
| 85 | */ |
| 86 | /* reset state */ |
| 87 | (void) bus_space_read_1(iot, ioh_6845, 10); |
| 88 | bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX, |
| 89 | 20 | 0x20); /* colselect | enable */ |
| 90 | regval = bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR); |
| 91 | /* toggle the implemented bits */ |
| 92 | bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval ^ 0x0f); |
| 93 | bus_space_write_1(iot, ioh_vga, VGA_ATC_INDEX, 20 | 0x20); |
| 94 | /* read back */ |
| 95 | if (bus_space_read_1(iot, ioh_vga, VGA_ATC_DATAR) != (regval ^ 0x0f)) |
| 96 | goto bad; |
| 97 | /* restore contents */ |
| 98 | bus_space_write_1(iot, ioh_vga, VGA_ATC_DATAW, regval); |
| 99 | |
| 100 | rv = 1; |
| 101 | bad: |
| 102 | if (gotio_vga) |
| 103 | bus_space_unmap(iot, ioh_vga, 0x10); |
| 104 | if (gotio_6845) |
| 105 | bus_space_unmap(iot, ioh_6845, 0x10); |
| 106 | if (gotmem) |
| 107 | bus_space_unmap(memt, memh, 0x20000); |
| 108 | |
| 109 | return (rv); |
| 110 | } |
| 111 | |