LXR linux/drivers/gpu/drm/nouveau/core/subdev/bios/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
  25#include <subdev/bios.h>
  26#include <subdev/bios/dcb.h>
  27#include <subdev/bios/extdev.h>
  28
  29static u16
  30extdev_table(struct nouveau_bios *bios, u8 *ver, u8 *hdr, u8 *len, u8 *cnt)
  31{
  32        u8  dcb_ver, dcb_hdr, dcb_cnt, dcb_len;
  33        u16 dcb, extdev = 0;
  34
  35        dcb = dcb_table(bios, &dcb_ver, &dcb_hdr, &dcb_cnt, &dcb_len);
  36        if (!dcb || (dcb_ver != 0x30 && dcb_ver != 0x40))
  37                return 0x0000;
  38
  39        extdev = nv_ro16(bios, dcb + 18);
  40        if (!extdev)
  41                return 0x0000;
  42
  43        *ver = nv_ro08(bios, extdev + 0);
  44        *hdr = nv_ro08(bios, extdev + 1);
  45        *cnt = nv_ro08(bios, extdev + 2);
  46        *len = nv_ro08(bios, extdev + 3);
  47
  48        return extdev + *hdr;
  49}
  50
  51static u16
  52nvbios_extdev_entry(struct nouveau_bios *bios, int idx, u8 *ver, u8 *len)
  53{
  54        u8 hdr, cnt;
  55        u16 extdev = extdev_table(bios, ver, &hdr, len, &cnt);
  56        if (extdev && idx < cnt)
  57                return extdev + idx * *len;
  58        return 0x0000;
  59}
  60
  61static void
  62extdev_parse_entry(struct nouveau_bios *bios, u16 offset,
  63                          struct nvbios_extdev_func *entry)
  64{
  65        entry->type = nv_ro08(bios, offset + 0);
  66        entry->addr = nv_ro08(bios, offset + 1);
  67        entry->bus = (nv_ro08(bios, offset + 2) >> 4) & 1;
  68}
  69
  70int
  71nvbios_extdev_parse(struct nouveau_bios *bios, int idx,
  72                    struct nvbios_extdev_func *func)
  73{
  74        u8 ver, len;
  75        u16 entry;
  76
  77        if (!(entry = nvbios_extdev_entry(bios, idx, &ver, &len)))
  78                return -EINVAL;
  79
  80        extdev_parse_entry(bios, entry, func);
  81
  82        return 0;
  83}
  84
  85int
  86nvbios_extdev_find(struct nouveau_bios *bios, enum nvbios_extdev_type type,
  87                   struct nvbios_extdev_func *func)
  88{
  89        u8 ver, len, i;
  90        u16 entry;
  91
  92        i = 0;
  93        while (!(entry = nvbios_extdev_entry(bios, i++, &ver, &len))) {
  94                extdev_parse_entry(bios, entry, func);
  95                if (func->type == type)
  96                        return 0;
  97        }
  98
  99        return -EINVAL;
 100}
 101