u-boot/board/freescale/m5235evb/m5235evb.c

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/*
* (C) Copyright 2000-2003
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* Copyright (C) 2004-2007 Freescale Semiconductor, Inc.
* TsiChung Liew (Tsi-Chung.Liew@freescale.com)
*
* 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 <config.h>
#include <common.h>
#include <asm/immap.h>
DECLARE_GLOBAL_DATA_PTR;
int checkboard(void)
{
puts("Board: ");
puts("Freescale M5235 EVB\n");
return 0;
};
phys_size_t initdram(int board_type)
{
volatile sdram_t *sdram = (volatile sdram_t *)(MMAP_SDRAM);
volatile gpio_t *gpio = (volatile gpio_t *)(MMAP_GPIO);
u32 dramsize, i, dramclk;
/*
* When booting from external Flash, the port-size is less than
* the port-size of SDRAM. In this case it is necessary to enable
* Data[15:0] on Port Address/Data.
*/
gpio->par_ad =
GPIO_PAR_AD_ADDR23 | GPIO_PAR_AD_ADDR22 | GPIO_PAR_AD_ADDR21 |
GPIO_PAR_AD_DATAL;
/* Initialize PAR to enable SDRAM signals */
gpio->par_sdram =
GPIO_PAR_SDRAM_SDWE | GPIO_PAR_SDRAM_SCAS | GPIO_PAR_SDRAM_SRAS |
GPIO_PAR_SDRAM_SCKE | GPIO_PAR_SDRAM_SDCS(3);
dramsize = CONFIG_SYS_SDRAM_SIZE * 0x100000;
for (i = 0x13; i < 0x20; i++) {
if (dramsize == (1 << i))
break;
}
i--;
if (!(sdram->dacr0 & SDRAMC_DARCn_RE)) {
dramclk = gd->bus_clk / (CONFIG_SYS_HZ * CONFIG_SYS_HZ);
/* Initialize DRAM Control Register: DCR */
sdram->dcr = SDRAMC_DCR_RTIM_9CLKS |
SDRAMC_DCR_RTIM_6CLKS | SDRAMC_DCR_RC((15 * dramclk) >> 4);
/* Initialize DACR0 */
sdram->dacr0 =
SDRAMC_DARCn_BA(CONFIG_SYS_SDRAM_BASE) | SDRAMC_DARCn_CASL_C1 |
SDRAMC_DARCn_CBM_CMD20 | SDRAMC_DARCn_PS_32;
asm("nop");
/* Initialize DMR0 */
sdram->dmr0 = ((dramsize - 1) & 0xFFFC0000) | SDRAMC_DMRn_V;
asm("nop");
/* Set IP (bit 3) in DACR */
sdram->dacr0 |= SDRAMC_DARCn_IP;
/* Wait 30ns to allow banks to precharge */
for (i = 0; i < 5; i++) {
asm("nop");
}
/* Write to this block to initiate precharge */
*(u32 *) (CONFIG_SYS_SDRAM_BASE) = 0xA5A59696;
/* Set RE (bit 15) in DACR */
sdram->dacr0 |= SDRAMC_DARCn_RE;
/* Wait for at least 8 auto refresh cycles to occur */
for (i = 0; i < 0x2000; i++) {
asm("nop");
}
/* Finish the configuration by issuing the MRS. */
sdram->dacr0 |= SDRAMC_DARCn_IMRS;
asm("nop");
/* Write to the SDRAM Mode Register */
*(u32 *) (CONFIG_SYS_SDRAM_BASE + 0x400) = 0xA5A59696;
}
return dramsize;
};
int testdram(void)
{
/* TODO: XXX XXX XXX */
printf("DRAM test not implemented!\n");
return (0);
}