arch/arm/mach-omap2/sdram-nokia.c

   1 /*
   2  * SDRC register values for Nokia boards
   3  *
   4  * Copyright (C) 2008, 2010-2011 Nokia Corporation
   5  *
   6  * Lauri Leukkunen <lauri.leukkunen@nokia.com>
   7  *
   8  * Original code by Juha Yrjola <juha.yrjola@solidboot.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/clk.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19
  20 #include <plat/io.h>
  21 #include "common.h"
  22 #include <plat/clock.h>
  23 #include <plat/sdrc.h>
  24
  25 #include "sdram-nokia.h"
  26
  27 /* In picoseconds, except for tREF (ns), tXP, tCKE, tWTR (clks) */
  28 struct sdram_timings {
  29         u32 casl;
  30         u32 tDAL;
  31         u32 tDPL;
  32         u32 tRRD;
  33         u32 tRCD;
  34         u32 tRP;
  35         u32 tRAS;
  36         u32 tRC;
  37         u32 tRFC;
  38         u32 tXSR;
  39
  40         u32 tREF; /* in ns */
  41
  42         u32 tXP;
  43         u32 tCKE;
  44         u32 tWTR;
  45 };
  46
  47 static const struct sdram_timings nokia_97dot6mhz_timings[] = {
  48         {
  49                 .casl = 3,
  50                 .tDAL = 30725,
  51                 .tDPL = 15362,
  52                 .tRRD = 10241,
  53                 .tRCD = 20483,
  54                 .tRP = 15362,
  55                 .tRAS = 40967,
  56                 .tRC = 56330,
  57                 .tRFC = 138266,
  58                 .tXSR = 204839,
  59
  60                 .tREF = 7798,
  61
  62                 .tXP = 2,
  63                 .tCKE = 4,
  64                 .tWTR = 2,
  65         },
  66 };
  67
  68 static const struct sdram_timings nokia_166mhz_timings[] = {
  69         {
  70                 .casl = 3,
  71                 .tDAL = 33000,
  72                 .tDPL = 15000,
  73                 .tRRD = 12000,
  74                 .tRCD = 22500,
  75                 .tRP = 18000,
  76                 .tRAS = 42000,
  77                 .tRC = 66000,
  78                 .tRFC = 138000,
  79                 .tXSR = 200000,
  80
  81                 .tREF = 7800,
  82
  83                 .tXP = 2,
  84                 .tCKE = 2,
  85                 .tWTR = 2
  86         },
  87 };
  88
  89 static const struct sdram_timings nokia_195dot2mhz_timings[] = {
  90         {
  91                 .casl = 3,
  92                 .tDAL = 30725,
  93                 .tDPL = 15362,
  94                 .tRRD = 10241,
  95                 .tRCD = 20483,
  96                 .tRP = 15362,
  97                 .tRAS = 40967,
  98                 .tRC = 56330,
  99                 .tRFC = 138266,
 100                 .tXSR = 204839,
 101
 102                 .tREF = 7752,
 103
 104                 .tXP = 2,
 105                 .tCKE = 4,
 106                 .tWTR = 2,
 107         },
 108 };
 109
 110 static const struct sdram_timings nokia_200mhz_timings[] = {
 111         {
 112                 .casl = 3,
 113                 .tDAL = 30000,
 114                 .tDPL = 15000,
 115                 .tRRD = 10000,
 116                 .tRCD = 20000,
 117                 .tRP = 15000,
 118                 .tRAS = 40000,
 119                 .tRC = 55000,
 120                 .tRFC = 140000,
 121                 .tXSR = 200000,
 122
 123                 .tREF = 7800,
 124
 125                 .tXP = 2,
 126                 .tCKE = 4,
 127                 .tWTR = 2
 128         },
 129 };
 130
 131 static const struct {
 132         long rate;
 133         struct sdram_timings const *data;
 134 } nokia_timings[] = {
 135         { 83000000, nokia_166mhz_timings },
 136         { 97600000, nokia_97dot6mhz_timings },
 137         { 100000000, nokia_200mhz_timings },
 138         { 166000000, nokia_166mhz_timings },
 139         { 195200000, nokia_195dot2mhz_timings },
 140         { 200000000, nokia_200mhz_timings },
 141 };
 142 static struct omap_sdrc_params nokia_sdrc_params[ARRAY_SIZE(nokia_timings) + 1];
 143
 144 static unsigned long sdrc_get_fclk_period(long rate)
 145 {
 146         /* In picoseconds */
 147         return 1000000000 / rate;
 148 }
 149
 150 static unsigned int sdrc_ps_to_ticks(unsigned int time_ps, long rate)
 151 {
 152         unsigned long tick_ps;
 153
 154         /* Calculate in picosecs to yield more exact results */
 155         tick_ps = sdrc_get_fclk_period(rate);
 156
 157         return (time_ps + tick_ps - 1) / tick_ps;
 158 }
 159 #undef DEBUG
 160 #ifdef DEBUG
 161 static int set_sdrc_timing_regval(u32 *regval, int st_bit, int end_bit,
 162                                 int ticks, long rate, const char *name)
 163 #else
 164 static int set_sdrc_timing_regval(u32 *regval, int st_bit, int end_bit,
 165                                int ticks)
 166 #endif
 167 {
 168         int mask, nr_bits;
 169
 170         nr_bits = end_bit - st_bit + 1;
 171         if (ticks >= 1 << nr_bits)
 172                 return -1;
 173         mask = (1 << nr_bits) - 1;
 174         *regval &= ~(mask << st_bit);
 175         *regval |= ticks << st_bit;
 176 #ifdef DEBUG
 177         printk(KERN_INFO "SDRC %s: %i ticks %i ns\n", name, ticks,
 178                         (unsigned int)sdrc_get_fclk_period(rate) * ticks /
 179                         1000);
 180 #endif
 181
 182         return 0;
 183 }
 184
 185 #ifdef DEBUG
 186 #define SDRC_SET_ONE(reg, st, end, field, rate) \
 187         if (set_sdrc_timing_regval((reg), (st), (end), \
 188                         memory_timings->field, (rate), #field) < 0) \
 189                 err = -1;
 190 #else
 191 #define SDRC_SET_ONE(reg, st, end, field, rate) \
 192         if (set_sdrc_timing_regval((reg), (st), (end), \
 193                         memory_timings->field) < 0) \
 194                 err = -1;
 195 #endif
 196
 197 #ifdef DEBUG
 198 static int set_sdrc_timing_regval_ps(u32 *regval, int st_bit, int end_bit,
 199                                 int time, long rate, const char *name)
 200 #else
 201 static int set_sdrc_timing_regval_ps(u32 *regval, int st_bit, int end_bit,
 202                                 int time, long rate)
 203 #endif
 204 {
 205         int ticks, ret;
 206         ret = 0;
 207
 208         if (time == 0)
 209                 ticks = 0;
 210         else
 211                 ticks = sdrc_ps_to_ticks(time, rate);
 212
 213 #ifdef DEBUG
 214         ret = set_sdrc_timing_regval(regval, st_bit, end_bit, ticks,
 215                                      rate, name);
 216 #else
 217         ret = set_sdrc_timing_regval(regval, st_bit, end_bit, ticks);
 218 #endif
 219
 220         return ret;
 221 }
 222
 223 #ifdef DEBUG
 224 #define SDRC_SET_ONE_PS(reg, st, end, field, rate) \
 225         if (set_sdrc_timing_regval_ps((reg), (st), (end), \
 226                         memory_timings->field, \
 227                         (rate), #field) < 0) \
 228                 err = -1;
 229
 230 #else
 231 #define SDRC_SET_ONE_PS(reg, st, end, field, rate) \
 232         if (set_sdrc_timing_regval_ps((reg), (st), (end), \
 233                         memory_timings->field, (rate)) < 0) \
 234                 err = -1;
 235 #endif
 236
 237 static int sdrc_timings(int id, long rate,
 238                         const struct sdram_timings *memory_timings)
 239 {
 240         u32 ticks_per_ms;
 241         u32 rfr, l;
 242         u32 actim_ctrla = 0, actim_ctrlb = 0;
 243         u32 rfr_ctrl;
 244         int err = 0;
 245         long l3_rate = rate / 1000;
 246
 247         SDRC_SET_ONE_PS(&actim_ctrla,  0,  4, tDAL, l3_rate);
 248         SDRC_SET_ONE_PS(&actim_ctrla,  6,  8, tDPL, l3_rate);
 249         SDRC_SET_ONE_PS(&actim_ctrla,  9, 11, tRRD, l3_rate);
 250         SDRC_SET_ONE_PS(&actim_ctrla, 12, 14, tRCD, l3_rate);
 251         SDRC_SET_ONE_PS(&actim_ctrla, 15, 17, tRP, l3_rate);
 252         SDRC_SET_ONE_PS(&actim_ctrla, 18, 21, tRAS, l3_rate);
 253         SDRC_SET_ONE_PS(&actim_ctrla, 22, 26, tRC, l3_rate);
 254         SDRC_SET_ONE_PS(&actim_ctrla, 27, 31, tRFC, l3_rate);
 255
 256         SDRC_SET_ONE_PS(&actim_ctrlb,  0,  7, tXSR, l3_rate);
 257
 258         SDRC_SET_ONE(&actim_ctrlb,  8, 10, tXP, l3_rate);
 259         SDRC_SET_ONE(&actim_ctrlb, 12, 14, tCKE, l3_rate);
 260         SDRC_SET_ONE(&actim_ctrlb, 16, 17, tWTR, l3_rate);
 261
 262         ticks_per_ms = l3_rate;
 263         rfr = memory_timings[0].tREF * ticks_per_ms / 1000000;
 264         if (rfr > 65535 + 50)
 265                 rfr = 65535;
 266         else
 267                 rfr -= 50;
 268
 269 #ifdef DEBUG
 270         printk(KERN_INFO "SDRC tREF: %i ticks\n", rfr);
 271 #endif
 272
 273         l = rfr << 8;
 274         rfr_ctrl = l | 0x1; /* autorefresh, reload counter with 1xARCV */
 275
 276         nokia_sdrc_params[id].rate = rate;
 277         nokia_sdrc_params[id].actim_ctrla = actim_ctrla;
 278         nokia_sdrc_params[id].actim_ctrlb = actim_ctrlb;
 279         nokia_sdrc_params[id].rfr_ctrl = rfr_ctrl;
 280         nokia_sdrc_params[id].mr = 0x32;
 281
 282         nokia_sdrc_params[id + 1].rate = 0;
 283
 284         return err;
 285 }
 286
 287 struct omap_sdrc_params *nokia_get_sdram_timings(void)
 288 {
 289         int err = 0;
 290         int i;
 291
 292         for (i = 0; i < ARRAY_SIZE(nokia_timings); i++) {
 293                 err |= sdrc_timings(i, nokia_timings[i].rate,
 294                                        nokia_timings[i].data);
 295                 if (err)
 296                         pr_err("%s: error with rate %ld: %d\n", __func__,
 297                                nokia_timings[i].rate, err);
 298         }
 299
 300         return err ? NULL : nokia_sdrc_params;
 301 }
 302