software/bios/ddrinit.c

   1 /*
   2  * Milkymist SoC (Software)
   3  * Copyright (C) 2012 Sebastien Bourdeauducq
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, version 3 of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20
  21 #include <hw/dfii.h>
  22
  23 #include "ddrinit.h"
  24
  25 static void cdelay(int i)
  26 {
  27         while(i > 0) {
  28                 __asm__ volatile("nop");
  29                 i--;
  30         }
  31 }
  32
  33 static void setaddr(int a)
  34 {
  35         CSR_DFII_AH_P0 = (a & 0x1fe0) >> 5;
  36         CSR_DFII_AL_P0 = a & 0x001f;
  37         CSR_DFII_AH_P1 = (a & 0x1fe0) >> 5;
  38         CSR_DFII_AL_P1 = a & 0x001f;
  39 }
  40
  41 static void init_sequence(void)
  42 {
  43         int i;
  44
  45         printf("Sending initialization sequence...\n");
  46
  47         /* Bring CKE high */
  48         setaddr(0x0000);
  49         CSR_DFII_BA_P0 = 0;
  50         CSR_DFII_CONTROL = DFII_CONTROL_CKE;
  51
  52         /* Precharge All */
  53         setaddr(0x0400);
  54         CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
  55
  56         /* Load Extended Mode Register */
  57         CSR_DFII_BA_P0 = 1;
  58         setaddr(0x0000);
  59         CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
  60         CSR_DFII_BA_P0 = 0;
  61
  62         /* Load Mode Register */
  63         setaddr(0x0132); /* Reset DLL, CL=3, BL=4 */
  64         CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
  65         cdelay(200);
  66
  67         /* Precharge All */
  68         setaddr(0x0400);
  69         CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
  70
  71         /* 2x Auto Refresh */
  72         for(i=0;i<2;i++) {
  73                 setaddr(0);
  74                 CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_CS;
  75                 cdelay(4);
  76         }
  77
  78         /* Load Mode Register */
  79         setaddr(0x0032); /* CL=3, BL=4 */
  80         CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
  81         cdelay(200);
  82 }
  83
  84 void ddrrd(char *startaddr)
  85 {
  86         char *c;
  87         unsigned int addr;
  88         int i;
  89
  90         if(*startaddr == 0) {
  91                 printf("ddrrd <address>\n");
  92                 return;
  93         }
  94         addr = strtoul(startaddr, &c, 0);
  95         if(*c != 0) {
  96                 printf("incorrect address\n");
  97                 return;
  98         }
  99
 100         setaddr(addr);
 101         CSR_DFII_BA_P0 = 0;
 102         CSR_DFII_COMMAND_P0 = DFII_COMMAND_CAS|DFII_COMMAND_CS|DFII_COMMAND_RDDATA;
 103         cdelay(15);
 104
 105         for(i=0;i<8;i++)
 106                 printf("%02x", MMPTR(0xe0000834+4*i));
 107         for(i=0;i<8;i++)
 108                 printf("%02x", MMPTR(0xe0000884+4*i));
 109         printf("\n");
 110 }
 111
 112 void ddrwr(char *startaddr)
 113 {
 114         char *c;
 115         unsigned int addr;
 116         int i;
 117
 118         if(*startaddr == 0) {
 119                 printf("ddrrd <address>\n");
 120                 return;
 121         }
 122         addr = strtoul(startaddr, &c, 0);
 123         if(*c != 0) {
 124                 printf("incorrect address\n");
 125                 return;
 126         }
 127
 128         for(i=0;i<8;i++) {
 129                 MMPTR(0xe0000814+4*i) = i;
 130                 MMPTR(0xe0000864+4*i) = 0xf0 + i;
 131         }
 132
 133         setaddr(addr);
 134         CSR_DFII_BA_P1 = 0;
 135         CSR_DFII_COMMAND_P1 = DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS|DFII_COMMAND_WRDATA;
 136 }
 137
 138 int ddrinit(void)
 139 {
 140         printf("Initializing DDR SDRAM...\n");
 141
 142         init_sequence();
 143
 144         setaddr(0x0000);
 145         CSR_DFII_BA_P0 = 0;
 146         CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CS;
 147         cdelay(15);
 148
 149         return 1;
 150 }