1 /* $NetBSD: nouveau_nvkm_subdev_bios_extdev.c,v 1.3 2021/12/18 23:45:38 riastradh Exp $ */
2
3 /*
4 * Copyright 2012 Nouveau Community
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors: Martin Peres
25 */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_bios_extdev.c,v 1.3 2021/12/18 23:45:38 riastradh Exp $");
28
29 #include <subdev/bios.h>
30 #include <subdev/bios/dcb.h>
31 #include <subdev/bios/extdev.h>
32
33 static u16
extdev_table(struct nvkm_bios * bios,u8 * ver,u8 * hdr,u8 * len,u8 * cnt)34 extdev_table(struct nvkm_bios *bios, u8 *ver, u8 *hdr, u8 *len, u8 *cnt)
35 {
36 u8 dcb_ver, dcb_hdr, dcb_cnt, dcb_len;
37 u16 dcb, extdev = 0;
38
39 dcb = dcb_table(bios, &dcb_ver, &dcb_hdr, &dcb_cnt, &dcb_len);
40 if (!dcb || (dcb_ver != 0x30 && dcb_ver != 0x40 && dcb_ver != 0x41))
41 return 0x0000;
42
43 extdev = nvbios_rd16(bios, dcb + 18);
44 if (!extdev)
45 return 0x0000;
46
47 *ver = nvbios_rd08(bios, extdev + 0);
48 *hdr = nvbios_rd08(bios, extdev + 1);
49 *cnt = nvbios_rd08(bios, extdev + 2);
50 *len = nvbios_rd08(bios, extdev + 3);
51 return extdev + *hdr;
52 }
53
54 bool
nvbios_extdev_skip_probe(struct nvkm_bios * bios)55 nvbios_extdev_skip_probe(struct nvkm_bios *bios)
56 {
57 u8 ver, hdr, len, cnt;
58 u16 data = extdev_table(bios, &ver, &hdr, &len, &cnt);
59 if (data && ver == 0x40 && hdr >= 5) {
60 u8 flags = nvbios_rd08(bios, data - hdr + 4);
61 if (flags & 1)
62 return true;
63 }
64 return false;
65 }
66
67 static u16
nvbios_extdev_entry(struct nvkm_bios * bios,int idx,u8 * ver,u8 * len)68 nvbios_extdev_entry(struct nvkm_bios *bios, int idx, u8 *ver, u8 *len)
69 {
70 u8 hdr, cnt;
71 u16 extdev = extdev_table(bios, ver, &hdr, len, &cnt);
72 if (extdev && idx < cnt)
73 return extdev + idx * *len;
74 return 0x0000;
75 }
76
77 static void
extdev_parse_entry(struct nvkm_bios * bios,u16 offset,struct nvbios_extdev_func * entry)78 extdev_parse_entry(struct nvkm_bios *bios, u16 offset,
79 struct nvbios_extdev_func *entry)
80 {
81 entry->type = nvbios_rd08(bios, offset + 0);
82 entry->addr = nvbios_rd08(bios, offset + 1);
83 entry->bus = (nvbios_rd08(bios, offset + 2) >> 4) & 1;
84 }
85
86 int
nvbios_extdev_parse(struct nvkm_bios * bios,int idx,struct nvbios_extdev_func * func)87 nvbios_extdev_parse(struct nvkm_bios *bios, int idx,
88 struct nvbios_extdev_func *func)
89 {
90 u8 ver, len;
91 u16 entry;
92
93 if (!(entry = nvbios_extdev_entry(bios, idx, &ver, &len)))
94 return -EINVAL;
95
96 extdev_parse_entry(bios, entry, func);
97 return 0;
98 }
99
100 int
nvbios_extdev_find(struct nvkm_bios * bios,enum nvbios_extdev_type type,struct nvbios_extdev_func * func)101 nvbios_extdev_find(struct nvkm_bios *bios, enum nvbios_extdev_type type,
102 struct nvbios_extdev_func *func)
103 {
104 u8 ver, len, i;
105 u16 entry;
106
107 i = 0;
108 while ((entry = nvbios_extdev_entry(bios, i++, &ver, &len))) {
109 extdev_parse_entry(bios, entry, func);
110 if (func->type == type)
111 return 0;
112 }
113
114 return -EINVAL;
115 }
116