LXR linux/drivers/gpu/drm/nouveau/nvkm/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#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}
 111