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 | |