LXR linux/drivers/gpu/drm/nouveau/nvkm/subdev/fb/sddr2.c

   1/*
   2 * Copyright 2014 Roy Spliet
   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: Roy Spliet <rspliet@eclipso.eu>
  23 *          Ben Skeggs
  24 */
  25#include "priv.h"
  26
  27struct ramxlat {
  28        int id;
  29        u8 enc;
  30};
  31
  32static inline int
  33ramxlat(const struct ramxlat *xlat, int id)
  34{
  35        while (xlat->id >= 0) {
  36                if (xlat->id == id)
  37                        return xlat->enc;
  38                xlat++;
  39        }
  40        return -EINVAL;
  41}
  42
  43static const struct ramxlat
  44ramddr2_cl[] = {
  45        { 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 },
  46        /* The following are available in some, but not all DDR2 docs */
  47        { 7, 7 },
  48        { -1 }
  49};
  50
  51static const struct ramxlat
  52ramddr2_wr[] = {
  53        { 2, 1 }, { 3, 2 }, { 4, 3 }, { 5, 4 }, { 6, 5 },
  54        /* The following are available in some, but not all DDR2 docs */
  55        { 7, 6 },
  56        { -1 }
  57};
  58
  59int
  60nvkm_sddr2_calc(struct nvkm_ram *ram)
  61{
  62        int CL, WR, DLL = 0, ODT = 0;
  63
  64        switch (ram->next->bios.timing_ver) {
  65        case 0x10:
  66                CL  = ram->next->bios.timing_10_CL;
  67                WR  = ram->next->bios.timing_10_WR;
  68                DLL = !ram->next->bios.ramcfg_DLLoff;
  69                ODT = ram->next->bios.timing_10_ODT & 3;
  70                break;
  71        case 0x20:
  72                CL  = (ram->next->bios.timing[1] & 0x0000001f);
  73                WR  = (ram->next->bios.timing[2] & 0x007f0000) >> 16;
  74                break;
  75        default:
  76                return -ENOSYS;
  77        }
  78
  79        CL  = ramxlat(ramddr2_cl, CL);
  80        WR  = ramxlat(ramddr2_wr, WR);
  81        if (CL < 0 || WR < 0)
  82                return -EINVAL;
  83
  84        ram->mr[0] &= ~0xf70;
  85        ram->mr[0] |= (WR & 0x07) << 9;
  86        ram->mr[0] |= (CL & 0x07) << 4;
  87
  88        ram->mr[1] &= ~0x045;
  89        ram->mr[1] |= (ODT & 0x1) << 2;
  90        ram->mr[1] |= (ODT & 0x2) << 5;
  91        ram->mr[1] |= !DLL;
  92        return 0;
  93}
  94