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
28static u16
29extdev_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))
36		return 0x0000;
37
38	extdev = nv_ro16(bios, dcb + 18);
39	if (!extdev)
40		return 0x0000;
41
42	*ver = nv_ro08(bios, extdev + 0);
43	*hdr = nv_ro08(bios, extdev + 1);
44	*cnt = nv_ro08(bios, extdev + 2);
45	*len = nv_ro08(bios, extdev + 3);
46	return extdev + *hdr;
47}
48
49static u16
50nvbios_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
59static void
60extdev_parse_entry(struct nvkm_bios *bios, u16 offset,
61		   struct nvbios_extdev_func *entry)
62{
63	entry->type = nv_ro08(bios, offset + 0);
64	entry->addr = nv_ro08(bios, offset + 1);
65	entry->bus = (nv_ro08(bios, offset + 2) >> 4) & 1;
66}
67
68int
69nvbios_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
82int
83nvbios_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