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