extdev.c

  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 && 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
 49bool
 50nvbios_extdev_skip_probe(struct nvkm_bios *bios)
 51{
 52	u8  ver, hdr, len, cnt;
 53	u16 data = extdev_table(bios, &ver, &hdr, &len, &cnt);
 54	if (data && ver == 0x40 && hdr >= 5) {
 55		u8 flags = nvbios_rd08(bios, data - hdr + 4);
 56		if (flags & 1)
 57			return true;
 58	}
 59	return false;
 60}
 61
 62static u16
 63nvbios_extdev_entry(struct nvkm_bios *bios, int idx, u8 *ver, u8 *len)
 64{
 65	u8 hdr, cnt;
 66	u16 extdev = extdev_table(bios, ver, &hdr, len, &cnt);
 67	if (extdev && idx < cnt)
 68		return extdev + idx * *len;
 69	return 0x0000;
 70}
 71
 72static void
 73extdev_parse_entry(struct nvkm_bios *bios, u16 offset,
 74		   struct nvbios_extdev_func *entry)
 75{
 76	entry->type = nvbios_rd08(bios, offset + 0);
 77	entry->addr = nvbios_rd08(bios, offset + 1);
 78	entry->bus = (nvbios_rd08(bios, offset + 2) >> 4) & 1;
 79}
 80
 81int
 82nvbios_extdev_parse(struct nvkm_bios *bios, int idx,
 83		    struct nvbios_extdev_func *func)
 84{
 85	u8 ver, len;
 86	u16 entry;
 87
 88	if (!(entry = nvbios_extdev_entry(bios, idx, &ver, &len)))
 89		return -EINVAL;
 90
 91	extdev_parse_entry(bios, entry, func);
 92	return 0;
 93}
 94
 95int
 96nvbios_extdev_find(struct nvkm_bios *bios, enum nvbios_extdev_type type,
 97		   struct nvbios_extdev_func *func)
 98{
 99	u8 ver, len, i;
100	u16 entry;
101
102	i = 0;
103	while ((entry = nvbios_extdev_entry(bios, i++, &ver, &len))) {
104		extdev_parse_entry(bios, entry, func);
105		if (func->type == type)
106			return 0;
107	}
108
109	return -EINVAL;
110}