litex/software/bios/ddrinit.c

153 lines
3.3 KiB
C

/*
* Milkymist SoC (Software)
* Copyright (C) 2012 Sebastien Bourdeauducq
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <stdlib.h>
#include <hw/dfii.h>
#include "ddrinit.h"
static void cdelay(int i)
{
while(i > 0) {
__asm__ volatile("nop");
i--;
}
}
static void setaddr(int a)
{
CSR_DFII_AH_P0 = (a & 0x1fe0) >> 5;
CSR_DFII_AL_P0 = a & 0x001f;
CSR_DFII_AH_P1 = (a & 0x1fe0) >> 5;
CSR_DFII_AL_P1 = a & 0x001f;
}
static void init_sequence(void)
{
int i;
printf("Sending initialization sequence...\n");
/* Bring CKE high */
setaddr(0x0000);
CSR_DFII_BA_P0 = 0;
CSR_DFII_CONTROL = DFII_CONTROL_CKE;
/* Precharge All */
setaddr(0x0400);
CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
/* Load Extended Mode Register */
CSR_DFII_BA_P0 = 1;
setaddr(0x0000);
CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
CSR_DFII_BA_P0 = 0;
/* Load Mode Register */
setaddr(0x0132); /* Reset DLL, CL=3, BL=4 */
//setaddr(0x0162); /* Reset DLL, CL=2.5, BL=4 */
CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
cdelay(200);
/* Precharge All */
setaddr(0x0400);
CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
/* 2x Auto Refresh */
for(i=0;i<2;i++) {
setaddr(0);
CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_CS;
cdelay(4);
}
/* Load Mode Register */
setaddr(0x0032); /* CL=3, BL=4 */
//setaddr(0x0062); /* CL=2.5, BL=4 */
CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS;
cdelay(200);
}
void ddrrd(char *startaddr)
{
char *c;
unsigned int addr;
int i;
if(*startaddr == 0) {
printf("ddrrd <address>\n");
return;
}
addr = strtoul(startaddr, &c, 0);
if(*c != 0) {
printf("incorrect address\n");
return;
}
setaddr(addr);
CSR_DFII_BA_P0 = 0;
CSR_DFII_COMMAND_P0 = DFII_COMMAND_CAS|DFII_COMMAND_CS|DFII_COMMAND_RDDATA;
cdelay(15);
for(i=0;i<8;i++)
printf("%02x", MMPTR(0xe0000834+4*i));
for(i=0;i<8;i++)
printf("%02x", MMPTR(0xe0000884+4*i));
printf("\n");
}
void ddrwr(char *startaddr)
{
char *c;
unsigned int addr;
int i;
if(*startaddr == 0) {
printf("ddrrd <address>\n");
return;
}
addr = strtoul(startaddr, &c, 0);
if(*c != 0) {
printf("incorrect address\n");
return;
}
for(i=0;i<8;i++) {
MMPTR(0xe0000814+4*i) = i;
MMPTR(0xe0000864+4*i) = 0xf0 + i;
}
setaddr(addr);
CSR_DFII_BA_P1 = 0;
CSR_DFII_COMMAND_P1 = DFII_COMMAND_CAS|DFII_COMMAND_WE|DFII_COMMAND_CS|DFII_COMMAND_WRDATA;
}
int ddrinit(void)
{
printf("Initializing DDR SDRAM...\n");
init_sequence();
setaddr(0x0000);
CSR_DFII_BA_P0 = 0;
CSR_DFII_COMMAND_P0 = DFII_COMMAND_RAS|DFII_COMMAND_CS;
cdelay(15);
return 1;
}