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
  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 }