drivers/gpu/drm/nouveau/nvkm/subdev/bios/ramcfg.c

   1 /*
   2  * Copyright 2013 Red Hat Inc.
   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: Ben Skeggs <bskeggs@redhat.com>
  23  */
  24 #include <subdev/bios.h>
  25 #include <subdev/bios/bit.h>
  26 #include <subdev/bios/ramcfg.h>
  27 #include <subdev/bios/M0203.h>
  28
  29 static u8
  30 nvbios_ramcfg_strap(struct nvkm_subdev *subdev)
  31 {
  32         return (nvkm_rd32(subdev->device, 0x101000) & 0x0000003c) >> 2;
  33 }
  34
  35 u8
  36 nvbios_ramcfg_count(struct nvkm_bios *bios)
  37 {
  38         struct bit_entry bit_M;
  39
  40         if (!bit_entry(bios, 'M', &bit_M)) {
  41                 if (bit_M.version == 1 && bit_M.length >= 5)
  42                         return nvbios_rd08(bios, bit_M.offset + 2);
  43                 if (bit_M.version == 2 && bit_M.length >= 3)
  44                         return nvbios_rd08(bios, bit_M.offset + 0);
  45         }
  46
  47         return 0x00;
  48 }
  49
  50 u8
  51 nvbios_ramcfg_index(struct nvkm_subdev *subdev)
  52 {
  53         struct nvkm_bios *bios = subdev->device->bios;
  54         u8 strap = nvbios_ramcfg_strap(subdev);
  55         u32 xlat = 0x00000000;
  56         struct bit_entry bit_M;
  57         struct nvbios_M0203E M0203E;
  58         u8 ver, hdr;
  59
  60         if (!bit_entry(bios, 'M', &bit_M)) {
  61                 if (bit_M.version == 1 && bit_M.length >= 5)
  62                         xlat = nvbios_rd16(bios, bit_M.offset + 3);
  63                 if (bit_M.version == 2 && bit_M.length >= 3) {
  64                         /*XXX: is M ever shorter than this?
  65                          *     if not - what is xlat used for now?
  66                          *     also - sigh..
  67                          */
  68                         if (bit_M.length >= 7 &&
  69                             nvbios_M0203Em(bios, strap, &ver, &hdr, &M0203E))
  70                                 return M0203E.group;
  71                         xlat = nvbios_rd16(bios, bit_M.offset + 1);
  72                 }
  73         }
  74
  75         if (xlat)
  76                 strap = nvbios_rd08(bios, xlat + strap);
  77         return strap;
  78 }