board/icu862/icu862.c

/*
 * (C) Copyright 2001
 * 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 <config.h>
#include <mpc8xx.h>

/*
 *  Memory Controller Using
 *
 *  CS0 - Flash memory            (0x40000000)
 *  CS1 - SDRAM                   (0x00000000}
 *  CS2 - S/UNI Ultra ATM155
 *  CS3 - IDT 77106 ATM25
 *  CS4 - DSP HPI
 *  CS5 - E1/T1 Interface device
 *  CS6 - PCMCIA device
 *  CS7 - PCMCIA device
 */

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

#define _not_used_	0xffffffff

const uint sdram_table[] = {
	/* single read. (offset 0 in upm RAM) */
	0x1f07fc04, 0xeeaefc04, 0x11adfc04, 0xefbbbc00,
	0x1ff77c47,

	/* MRS initialization (offset 5) */

	0x1ff77c34, 0xefeabc34, 0x1fb57c35,

	/* burst read. (offset 8 in upm RAM) */
	0x1f07fc04, 0xeeaefc04, 0x10adfc04, 0xf0affc00,
	0xf0affc00, 0xf1affc00, 0xefbbbc00, 0x1ff77c47,
	_not_used_, _not_used_, _not_used_, _not_used_,
	_not_used_, _not_used_, _not_used_, _not_used_,

	/* single write. (offset 18 in upm RAM) */
	0x1f27fc04, 0xeeaebc00, 0x01b93c04, 0x1ff77c47,
	_not_used_, _not_used_, _not_used_, _not_used_,

	/* burst write. (offset 20 in upm RAM) */
	0x1f07fc04, 0xeeaebc00, 0x10ad7c00, 0xf0affc00,
	0xf0affc00, 0xe1bbbc04, 0x1ff77c47, _not_used_,
	_not_used_, _not_used_, _not_used_, _not_used_,
	_not_used_, _not_used_, _not_used_, _not_used_,

	/* refresh. (offset 30 in upm RAM) */
	0x1ff5fc84, 0xfffffc04, 0xfffffc04, 0xfffffc04,
	0xfffffc84, 0xfffffc07, _not_used_, _not_used_,
	_not_used_, _not_used_, _not_used_, _not_used_,

	/* exception. (offset 3c in upm RAM) */
	0x7ffffc07, _not_used_, _not_used_, _not_used_
};

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

/*
 * Check Board Identity:
 */

int checkboard (void)
{
	puts ("Board: ICU862 Board\n");
	return 0;
}

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

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

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

long int initdram (int board_type)
{
	volatile immap_t *immap = (immap_t *) CFG_IMMR;
	volatile memctl8xx_t *memctl = &immap->im_memctl;
	long int size8, size9;
	long int size_b0 = 0;
	unsigned long reg;

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

	/*
	 * Preliminary prescaler for refresh (depends on number of
	 * banks): This value is selected for four cycles every 62.4 us
	 * with two SDRAM banks or four cycles every 31.2 us with one
	 * bank. It will be adjusted after memory sizing.
	 */
	memctl->memc_mptpr = CFG_MPTPR_2BK_8K;

	memctl->memc_mar = 0x00000088;

	/*
	 * Map controller bank 1 to the SDRAM bank at
	 * preliminary address - these have to be modified after the
	 * SDRAM size has been determined.
	 */
	memctl->memc_or1 = CFG_OR1_PRELIM;
	memctl->memc_br1 = CFG_BR1_PRELIM;

	memctl->memc_mamr = CFG_MAMR_8COL & (~(MAMR_PTAE));	/* no refresh yet */

	udelay (200);

	/* perform SDRAM initializsation sequence */

	memctl->memc_mcr = 0x80002105;	/* SDRAM bank 0 */
	udelay (200);
	memctl->memc_mcr = 0x80002230;	/* SDRAM bank 0 - execute twice */
	udelay (200);

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

	udelay (1000);

	/*
	 * Check Bank 0 Memory Size for re-configuration
	 *
	 * try 8 column mode
	 */
	size8 = dram_size (CFG_MAMR_8COL, (ulong *) SDRAM_BASE1_PRELIM,
					   SDRAM_MAX_SIZE);

	udelay (1000);

	/*
	 * try 9 column mode
	 */
	size9 = dram_size (CFG_MAMR_9COL, (ulong *) SDRAM_BASE1_PRELIM,
					   SDRAM_MAX_SIZE);

	if (size8 < size9) {		/* leave configuration at 9 columns */
		size_b0 = size9;
/*	debug ("SDRAM Bank 0 in 9 column mode: %ld MB\n", size >> 20);	*/
	} else {					/* back to 8 columns            */
		size_b0 = size8;
		memctl->memc_mamr = CFG_MAMR_8COL;
		udelay (500);
/*	debug ("SDRAM Bank 0 in 8 column mode: %ld MB\n", size >> 20);	*/
	}

	udelay (1000);

	/*
	 * Adjust refresh rate depending on SDRAM type, both banks
	 * For types > 128 MBit leave it at the current (fast) rate
	 */
	if ((size_b0 < 0x02000000)) {
		/* reduce to 15.6 us (62.4 us / quad) */
		memctl->memc_mptpr = CFG_MPTPR_2BK_4K;
		udelay (1000);
	}

	/*
	 * Final mapping
	 */

	memctl->memc_or1 = ((-size_b0) & 0xFFFF0000) | CFG_OR_TIMING_SDRAM;
	memctl->memc_br1 = (CFG_SDRAM_BASE & BR_BA_MSK) | BR_MS_UPMA | BR_V;

	/* adjust refresh rate depending on SDRAM type, one bank */
	reg = memctl->memc_mptpr;
	reg >>= 1;					/* reduce to CFG_MPTPR_1BK_8K / _4K */
	memctl->memc_mptpr = reg;

	udelay (10000);

	return (size_b0);
}

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

/*
 * 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);
}