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