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/*
* (C) Copyright 2000-2006
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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; either version 2 of
* the License, or (at your option) any later version.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <asm/immap.h>
int checkboard (void) {
puts ("Board: iDMR\n");
return 0;
};
long int initdram (int board_type) {
int i;
/*
* After reset, CS0 is configured to cover entire address space. We
* need to configure it to its proper values, so that writes to
* CFG_SDRAM_BASE and vicinity during SDRAM controller setup below do
* now fall under CS0 (see 16.3.1 of the MCF5271 Reference Manual).
*/
/* Flash chipselect, CS0 */
/* ;CSAR0: Flash at 0xFF800000 */
mbar_writeShort(0x0080, 0xFF80);
/* CSCR0: Flash 6 waits, 16bit */
mbar_writeShort(0x008A, 0x1980);
/* CSMR0: Flash 8MB, R/W, valid */
mbar_writeLong(0x0084, 0x007F0001);
/*
* SDRAM configuration proper
*/
/*
* Address/Data Pin Assignment Reg.: enable address lines 23-21; do
* not enable data pins D[15:0], as we have 16 bit port to SDRAM
*/
mbar_writeByte(MCF_GPIO_PAR_AD,
MCF_GPIO_AD_ADDR23 |
MCF_GPIO_AD_ADDR22 |
MCF_GPIO_AD_ADDR21);
/* No need to configure BS pins - reset values are OK */
/* Chip Select Pin Assignment Reg.: set CS[1-7] to GPIO */
mbar_writeByte(MCF_GPIO_PAR_CS, 0x00);
/* SDRAM Control Pin Assignment Reg. */
mbar_writeByte(MCF_GPIO_PAR_SDRAM,
MCF_GPIO_SDRAM_CSSDCS_00 | /* no matter: PAR_CS=0 */
MCF_GPIO_SDRAM_SDWE |
MCF_GPIO_SDRAM_SCAS |
MCF_GPIO_SDRAM_SRAS |
MCF_GPIO_SDRAM_SCKE |
MCF_GPIO_SDRAM_SDCS_01);
/*
* Wait 100us. We run the bus at 50Mhz, one cycle is 20ns. So 5
* iterations will do, but we do 10 just to be safe.
*/
for (i = 0; i < 10; ++i)
asm(" nop");
/* 1. Initialize DRAM Control Register: DCR */
mbar_writeShort(MCF_SDRAMC_DCR,
MCF_SDRAMC_DCR_RTIM(0x10) | /* 65ns */
MCF_SDRAMC_DCR_RC(0x60)); /* 1562 cycles */
/*
* 2. Initialize DACR0
*
* CL: 11 (CL=3: 0x03, 0x02; CL=2: 0x1)
* CBM: cmd at A20, bank select bits 21 and up
* PS: 16 bit
*/
mbar_writeLong(MCF_SDRAMC_DACR0,
MCF_SDRAMC_DACRn_BA(CFG_SDRAM_BASE>>18) |
MCF_SDRAMC_DACRn_BA(0x00) |
MCF_SDRAMC_DACRn_CASL(0x03) |
MCF_SDRAMC_DACRn_CBM(0x03) |
MCF_SDRAMC_DACRn_PS(0x03));
/* Initialize DMR0 */
mbar_writeLong(MCF_SDRAMC_DMR0,
MCF_SDRAMC_DMRn_BAM_16M |
MCF_SDRAMC_DMRn_V);
/* 3. Set IP bit in DACR to initiate PALL command */
mbar_writeLong(MCF_SDRAMC_DACR0,
mbar_readLong(MCF_SDRAMC_DACR0) |
MCF_SDRAMC_DACRn_IP);
/* Write to this block to initiate precharge */
*(volatile u16 *)(CFG_SDRAM_BASE) = 0xa5a5;
/*
* Wait at least 20ns to allow banks to precharge (t_RP = 20ns). We
* wait a wee longer, just to be safe.
*/
for (i = 0; i < 5; ++i)
asm(" nop");
/* 4. Set RE bit in DACR */
mbar_writeLong(MCF_SDRAMC_DACR0,
mbar_readLong(MCF_SDRAMC_DACR0) |
MCF_SDRAMC_DACRn_RE);
/*
* Wait for at least 8 auto refresh cycles to occur, i.e. at least
* 781 bus cycles.
*/
for (i = 0; i < 1000; ++i)
asm(" nop");
/* Finish the configuration by issuing the MRS */
mbar_writeLong(MCF_SDRAMC_DACR0,
mbar_readLong(MCF_SDRAMC_DACR0) |
MCF_SDRAMC_DACRn_MRS);
/*
* Write to the SDRAM Mode Register A0-A11 = 0x400
*
* Write Burst Mode = Programmed Burst Length
* Op Mode = Standard Op
* CAS Latency = 3
* Burst Type = Sequential
* Burst Length = 1
*/
*(volatile u32 *)(CFG_SDRAM_BASE + 0x1800) = 0xa5a5a5a5;
return CFG_SDRAM_SIZE * 1024 * 1024;
};
int testdram (void) {
/* TODO: XXX XXX XXX */
printf ("DRAM test not implemented!\n");
return (0);
}
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