LXR linux/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
  29static u8
  30nvbios_ramcfg_strap(struct nvkm_subdev *subdev)
  31{
  32        return (nvkm_rd32(subdev->device, 0x101000) & 0x0000003c) >> 2;
  33}
  34
  35u8
  36nvbios_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
  50u8
  51nvbios_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}
  79