board/rmu/rmu.c

/*
 * (C) Copyright 2000
 * 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 <mpc8xx.h>

/* ------------------------------------------------------------------------- */

static long int dram_size (long int, long int *, long int);

/* ------------------------------------------------------------------------- */

#define	_NOT_USED_	0xFFFFCC25

const uint sdram_table[] =
{
	/*
	 * Single Read. (Offset 00h in UPMA RAM)
	 */
	0x0F03CC04, 0x00ACCC24, 0x1FF74C20, _NOT_USED_,
	_NOT_USED_, _NOT_USED_, _NOT_USED_, _NOT_USED_,

	/*
	 * Burst Read. (Offset 08h in UPMA RAM)
	 */
	0x0F03CC04, 0x00ACCC24, 0x00FFCC20, 0x00FFCC20,
	0x01FFCC20, 0x1FF74C20, _NOT_USED_, _NOT_USED_,
	_NOT_USED_, _NOT_USED_, _NOT_USED_, _NOT_USED_,
	_NOT_USED_, _NOT_USED_, _NOT_USED_, _NOT_USED_,

	/*
	 * Single Write. (Offset 18h in UPMA RAM)
	 */
	0x0F03CC02, 0x00AC0C24, 0x1FF74C25, _NOT_USED_,
	_NOT_USED_, _NOT_USED_, _NOT_USED_, _NOT_USED_,

	/*
	 * Burst Write. (Offset 20h in UPMA RAM)
	 */
	0x0F03CC00, 0x00AC0C20, 0x00FFFC20, 0x00FFFC22,
	0x01FFFC24, 0x1FF74C25, _NOT_USED_, _NOT_USED_,
	_NOT_USED_, _NOT_USED_, _NOT_USED_, _NOT_USED_,
	_NOT_USED_, _NOT_USED_, _NOT_USED_, _NOT_USED_,

	/*
	 * Refresh. (Offset 30h in UPMA RAM)
	 * (Initialization code at 0x36)
	 */
	0x0FF0CC24, 0xFFFFCC24, _NOT_USED_, _NOT_USED_,
	_NOT_USED_, _NOT_USED_, 0xEFFB8C34, 0x0FF74C34,
	0x0FFACCB4, 0x0FF5CC34, 0x0FFCC34, 0x0FFFCCB4,

	/*
	 * Exception. (Offset 3Ch in UPMA RAM)
	 */
	0x0FEA8C34, 0x1FB54C34, 0xFFFFCC34, _NOT_USED_
};

/* ------------------------------------------------------------------------- */


/*
 * Check Board Identity:
 */

int checkboard (void)
{
	puts ("Board: RMU\n") ;
	return (0) ;
}

/* ------------------------------------------------------------------------- */

long int initdram (int board_type)
{
    volatile immap_t     *immap  = (immap_t *)CFG_IMMR;
    volatile memctl8xx_t *memctl = &immap->im_memctl;
    long int size10 ;

    upmconfig(UPMA, (uint *)sdram_table, sizeof(sdram_table)/sizeof(uint));

	/* Refresh clock prescalar */
    memctl->memc_mptpr = CFG_MPTPR ;

    memctl->memc_mar  = 0x00000088;

	/* Map controller banks 1 to the SDRAM bank */
    memctl->memc_or1 = CFG_OR1_PRELIM;
    memctl->memc_br1 = CFG_BR1_PRELIM;

    memctl->memc_mamr = CFG_MAMR_10COL & (~(MAMR_PTAE)); /* no refresh yet */

    udelay(200);

    /* perform SDRAM initializsation sequence */

	memctl->memc_mcr  = 0x80002136 ; /* SDRAM bank 0 */
    udelay(1);

    memctl->memc_mamr |= MAMR_PTAE;	/* enable refresh */

    udelay (1000);

	/* Check Bank 0 Memory Size
	 * try 10 column mode
	 */

	size10 = dram_size (CFG_MAMR_10COL, (ulong *)SDRAM_BASE_PRELIM, SDRAM_MAX_SIZE) ;

    return (size10);
}

/* ------------------------------------------------------------------------- */

/*
 * Check memory range for valid RAM. A simple memory test determines
 * the actually available RAM size between addresses `base' and
 * `base + maxsize'. Some (not all) hardware errors are detected:
 * - short between address lines
 * - short between data lines
 */

static long int dram_size (long int mamr_value, long int *base, long int maxsize)
{
    volatile immap_t     *immap  = (immap_t *)CFG_IMMR;
    volatile memctl8xx_t *memctl = &immap->im_memctl;
    volatile long int	 *addr;
    ulong		  cnt, val;
    ulong		  save[32];	/* to make test non-destructive */
    unsigned char	  i = 0;

    memctl->memc_mamr = mamr_value;

    for (cnt = maxsize/sizeof(long); cnt > 0; cnt >>= 1) {
	addr = base + cnt;	/* pointer arith! */

	save[i++] = *addr;
	*addr = ~cnt;
    }

    /* write 0 to base address */
    addr = base;
    save[i] = *addr;
    *addr = 0;

    /* check at base address */
    if ((val = *addr) != 0) {
	*addr = save[i];
	return (0);
    }

    for (cnt = 1; cnt <= maxsize/sizeof(long); cnt <<= 1) {
	addr = base + cnt;	/* pointer arith! */

	val = *addr;
	*addr = save[--i];

	if (val != (~cnt)) {
	    return (cnt * sizeof(long));
	}
    }
    return (maxsize);
}