sdram.c

U-BOOT,著名的Bootloader程序

/*
 * (C) Copyright 2006
 * Sylvie Gohl,             AMCC/IBM, [e-mail]
 * Jacqueline Pira-Ferriol, AMCC/IBM, [e-mail]
 * Thierry Roman,           AMCC/IBM, [e-mail]
 * Alain Saurel,            AMCC/IBM, [e-mail]
 * Robert Snyder,           AMCC/IBM, [e-mail]
 *
 * (C) Copyright 2006-2007
 * Stefan Roese, DENX Software Engineering, [e-mail].
 *
 * 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
 */

/* define DEBUG for debug output */
#undef DEBUG

#include <common.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <ppc440.h>

/*-----------------------------------------------------------------------------+
 * Prototypes
 *-----------------------------------------------------------------------------*/
extern int denali_wait_for_dlllock(void);
extern void denali_core_search_data_eye(void);

#if defined(CONFIG_NAND_SPL)
/* Using cpu/ppc4xx/speed.c to calculate the bus frequency is too big
 * for the 4k NAND boot image so define bus_frequency to 133MHz here
 * which is save for the refresh counter setup.
 */
#define get_bus_freq(val)	133000000
#endif

/*************************************************************************
 *
 * initdram -- 440EPx's DDR controller is a DENALI Core
 *
 ************************************************************************/
phys_size_t initdram (int board_type)
{
#if !defined(CONFIG_NAND_U_BOOT) || defined(CONFIG_NAND_SPL)
#if !defined(CONFIG_NAND_SPL)
	ulong speed = get_bus_freq(0);
#else
	ulong speed = 133333333;	/* 133MHz is on the safe side	*/
#endif

	mtsdram(DDR0_02, 0x00000000);

	mtsdram(DDR0_00, 0x0000190A);
	mtsdram(DDR0_01, 0x01000000);
	mtsdram(DDR0_03, 0x02030602);
	mtsdram(DDR0_04, 0x0A020200);
	mtsdram(DDR0_05, 0x02020308);
	mtsdram(DDR0_06, 0x0102C812);
	mtsdram(DDR0_07, 0x000D0100);
	mtsdram(DDR0_08, 0x02430001);
	mtsdram(DDR0_09, 0x00011D5F);
	mtsdram(DDR0_10, 0x00000300);
	mtsdram(DDR0_11, 0x0027C800);
	mtsdram(DDR0_12, 0x00000003);
	mtsdram(DDR0_14, 0x00000000);
	mtsdram(DDR0_17, 0x19000000);
	mtsdram(DDR0_18, 0x19191919);
	mtsdram(DDR0_19, 0x19191919);
	mtsdram(DDR0_20, 0x0B0B0B0B);
	mtsdram(DDR0_21, 0x0B0B0B0B);
	mtsdram(DDR0_22, 0x00267F0B);
	mtsdram(DDR0_23, 0x00000000);
	mtsdram(DDR0_24, 0x01010002);
	if (speed > 133333334)
		mtsdram(DDR0_26, 0x5B26050C);
	else
		mtsdram(DDR0_26, 0x5B260408);
	mtsdram(DDR0_27, 0x0000682B);
	mtsdram(DDR0_28, 0x00000000);
	mtsdram(DDR0_31, 0x00000000);
	mtsdram(DDR0_42, 0x01000006);
	mtsdram(DDR0_43, 0x030A0200);
	mtsdram(DDR0_44, 0x00000003);
	mtsdram(DDR0_02, 0x00000001);

	denali_wait_for_dlllock();
#endif /* #ifndef CONFIG_NAND_U_BOOT */

#ifdef CONFIG_DDR_DATA_EYE
	/* -----------------------------------------------------------+
	 * Perform data eye search if requested.
	 * ----------------------------------------------------------*/
	denali_core_search_data_eye();
#endif

	/*
	 * Clear possible errors resulting from data-eye-search.
	 * If not done, then we could get an interrupt later on when
	 * exceptions are enabled.
	 */
	set_mcsr(get_mcsr());

	return (CFG_MBYTES_SDRAM << 20);
}