cpu/ppc4xx/spd_sdram.c

/*
 * (C) Copyright 2001
 * Bill Hunter, Wave 7 Optics, williamhunter@attbi.com
 *
 * Based on code by:
 *
 * Kenneth Johansson ,Ericsson AB.
 * kenneth.johansson@etx.ericsson.se
 *
 * hacked up by bill hunter. fixed so we could run before
 * serial_init and console_init. previous version avoided this by
 * running out of cache memory during serial/console init, then running
 * this code later.
 *
 * (C) Copyright 2002
 * Jun Gu, Artesyn Technology, jung@artesyncp.com
 * Support for IBM 440 based on OpenBIOS draminit.c from IBM.
 *
 * 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/processor.h>
#include <i2c.h>
#include <ppc4xx.h>

#ifdef CONFIG_SPD_EEPROM

/*
 * Set default values
 */
#ifndef	CFG_I2C_SPEED
#define	CFG_I2C_SPEED	50000
#endif

#ifndef	CFG_I2C_SLAVE
#define	CFG_I2C_SLAVE	0xFE
#endif

#ifndef  CONFIG_440              /* for 405 WALNUT board */

#define  SDRAM0_CFG_DCE          0x80000000
#define  SDRAM0_CFG_SRE          0x40000000
#define  SDRAM0_CFG_PME          0x20000000
#define  SDRAM0_CFG_MEMCHK       0x10000000
#define  SDRAM0_CFG_REGEN        0x08000000
#define  SDRAM0_CFG_ECCDD        0x00400000
#define  SDRAM0_CFG_EMDULR       0x00200000
#define  SDRAM0_CFG_DRW_SHIFT    (31-6)
#define  SDRAM0_CFG_BRPF_SHIFT   (31-8)

#define  SDRAM0_TR_CASL_SHIFT    (31-8)
#define  SDRAM0_TR_PTA_SHIFT     (31-13)
#define  SDRAM0_TR_CTP_SHIFT     (31-15)
#define  SDRAM0_TR_LDF_SHIFT     (31-17)
#define  SDRAM0_TR_RFTA_SHIFT    (31-29)
#define  SDRAM0_TR_RCD_SHIFT     (31-31)

#define  SDRAM0_RTR_SHIFT        (31-15)
#define  SDRAM0_ECCCFG_SHIFT     (31-11)

/* SDRAM0_CFG enable macro  */
#define SDRAM0_CFG_BRPF(x) ( ( x & 0x3)<< SDRAM0_CFG_BRPF_SHIFT )

#define SDRAM0_BXCR_SZ_MASK  0x000e0000
#define SDRAM0_BXCR_AM_MASK  0x0000e000

#define SDRAM0_BXCR_SZ_SHIFT (31-14)
#define SDRAM0_BXCR_AM_SHIFT (31-18)

#define SDRAM0_BXCR_SZ(x)  ( (( x << SDRAM0_BXCR_SZ_SHIFT) & SDRAM0_BXCR_SZ_MASK) )
#define SDRAM0_BXCR_AM(x)  ( (( x << SDRAM0_BXCR_AM_SHIFT) & SDRAM0_BXCR_AM_MASK) )

#ifdef CONFIG_SPDDRAM_SILENT
# define SPD_ERR(x) do { return 0; } while (0)
#else
# define SPD_ERR(x) do { printf(x); return(0); } while (0)
#endif

#define sdram_HZ_to_ns(hertz) (1000000000/(hertz))

/* function prototypes */
int spd_read(uint addr);


/*
 * This function is reading data from the DIMM module EEPROM over the SPD bus
 * and uses that to program the sdram controller.
 *
 * This works on boards that has the same schematics that the IBM walnut has.
 *
 * Input: null for default I2C spd functions or a pointer to a custom function
 * returning spd_data.
 */

long int spd_sdram(int(read_spd)(uint addr))
{
	int bus_period,tmp,row,col;
	int total_size,bank_size,bank_code;
	int ecc_on;
	int mode;
	int bank_cnt;

	int sdram0_pmit=0x07c00000;
#ifndef CONFIG_405EP /* not on PPC405EP */
	int sdram0_besr0=-1;
	int sdram0_besr1=-1;
	int sdram0_eccesr=-1;
#endif
	int sdram0_ecccfg;

	int sdram0_rtr=0;
	int sdram0_tr=0;

	int sdram0_b0cr;
	int sdram0_b1cr;
	int sdram0_b2cr;
	int sdram0_b3cr;

	int sdram0_cfg=0;

	int t_rp;
	int t_rcd;
	int t_ras;
	int t_rc;
	int min_cas;

	if(read_spd == 0){
		read_spd=spd_read;
	/*
	 * Make sure I2C controller is initialized
	 * before continuing.
	 */
		i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE);
	}


	/*
	 * Calculate the bus period, we do it this
	 * way to minimize stack utilization.
	 */
#ifndef CONFIG_405EP
    	tmp = (mfdcr(pllmd) >> (31-6)) & 0xf;	/* get FBDV bits */
	tmp = CONFIG_SYS_CLK_FREQ * tmp;	/* get plb freq */
#else
	{
		unsigned long freqCPU;
		unsigned long pllmr0;
		unsigned long pllmr1;
		unsigned long pllFbkDiv;
		unsigned long pllPlbDiv;
		unsigned long pllmr0_ccdv;

		/*
		 * Read PLL Mode registers
		 */
		pllmr0 = mfdcr (cpc0_pllmr0);
		pllmr1 = mfdcr (cpc0_pllmr1);

		pllFbkDiv = ((pllmr1 & PLLMR1_FBMUL_MASK) >> 20);
		if (pllFbkDiv == 0) {
			pllFbkDiv = 16;
		}
		pllPlbDiv = ((pllmr0 & PLLMR0_CPU_TO_PLB_MASK) >> 16) + 1;

		/*
		 * Determine CPU clock frequency
		 */
		pllmr0_ccdv = ((pllmr0 & PLLMR0_CPU_DIV_MASK) >> 20) + 1;
		if (pllmr1 & PLLMR1_SSCS_MASK) {
			freqCPU = (CONFIG_SYS_CLK_FREQ * pllFbkDiv) / pllmr0_ccdv;
		} else {
			freqCPU = CONFIG_SYS_CLK_FREQ / pllmr0_ccdv;
		}

		/*
		 * Determine PLB clock frequency
		 */
		tmp = freqCPU / pllPlbDiv;
	}
#endif
	bus_period = sdram_HZ_to_ns(tmp);	/* get sdram speed */

     	/* Make shure we are using SDRAM */
	if (read_spd(2) != 0x04){
          SPD_ERR("SDRAM - non SDRAM memory module found\n");
     	  }

/*------------------------------------------------------------------
  configure memory timing register

  data from DIMM:
  27	IN Row Precharge Time ( t RP)
  29	MIN RAS to CAS Delay ( t RCD)
  127   Component and Clock Detail ,clk0-clk3, junction temp, CAS
  -------------------------------------------------------------------*/

     /*
      * first figure out which cas latency mode to use
      * use the min supported mode
      */

	tmp = read_spd(127) & 0x6;
     if(tmp == 0x02){      	   /* only cas = 2 supported */
     	  min_cas = 2;
/*     	  t_ck = read_spd(9); */
/*     	  t_ac = read_spd(10); */
	  }
     else if (tmp == 0x04){         /* only cas = 3 supported */
     	  min_cas = 3;
/*     	  t_ck = read_spd(9); */
/*     	  t_ac = read_spd(10); */
	  }
     else if (tmp == 0x06){         /* 2,3 supported, so use 2 */
     	  min_cas = 2;
/*     	  t_ck = read_spd(23); */
/*     	  t_ac = read_spd(24); */
	  }
     else {
	     SPD_ERR("SDRAM - unsupported CAS latency \n");
	}

     /* get some timing values, t_rp,t_rcd,t_ras,t_rc
     */
     t_rp = read_spd(27);
     t_rcd = read_spd(29);
     t_ras = read_spd(30);
     t_rc = t_ras + t_rp;

     /* The following timing calcs subtract 1 before deviding.
      * this has effect of using ceiling instead of floor rounding,
      * and also subtracting 1 to convert number to reg value
      */
     /* set up CASL */
     sdram0_tr = (min_cas - 1) << SDRAM0_TR_CASL_SHIFT;
     /* set up PTA */
     sdram0_tr |= (((t_rp - 1)/bus_period) & 0x3) << SDRAM0_TR_PTA_SHIFT;
     /* set up CTP */
     tmp = ((t_rc - t_rcd - t_rp -1) / bus_period) & 0x3;
     if(tmp<1) tmp=1;
     sdram0_tr |= tmp << SDRAM0_TR_CTP_SHIFT;
     /* set LDF	= 2 cycles, reg value = 1 */
     sdram0_tr |= 1 << SDRAM0_TR_LDF_SHIFT;
     /* set RFTA = t_rfc/bus_period, use t_rfc = t_rc */
	tmp = ( (t_rc - 1) / bus_period)-3;
	if(tmp<0)tmp=0;
	if(tmp>6)tmp=6;
	sdram0_tr |= tmp << SDRAM0_TR_RFTA_SHIFT;
     /* set RCD = t_rcd/bus_period*/
     sdram0_tr |= (((t_rcd - 1) / bus_period) &0x3) << SDRAM0_TR_RCD_SHIFT ;


/*------------------------------------------------------------------
  configure RTR register
  -------------------------------------------------------------------*/
     row = read_spd(3);
     col = read_spd(4);
     tmp = read_spd(12) & 0x7f ; /* refresh type less self refresh bit */
     switch(tmp){
	case 0x00:
	  tmp=15625;
	  break;
	case 0x01:
	  tmp=15625/4;
	  break;
	case 0x02:
	  tmp=15625/2;
	  break;
	case 0x03:
	  tmp=15625*2;
	  break;
	case 0x04:
	  tmp=15625*4;
	  break;
	case 0x05:
	  tmp=15625*8;
	  break;
	default:
     	  SPD_ERR("SDRAM - Bad refresh period \n");
	}
	/* convert from nsec to bus cycles */
	tmp = tmp/bus_period;
	sdram0_rtr = (tmp & 0x3ff8)<<  SDRAM0_RTR_SHIFT;

/*------------------------------------------------------------------
  determine the number of banks used
  -------------------------------------------------------------------*/
	/* byte 7:6 is module data width */
	if(read_spd(7) != 0)
	    SPD_ERR("SDRAM - unsupported module width\n");
	tmp = read_spd(6);
	if (tmp < 32)
	    SPD_ERR("SDRAM - unsupported module width\n");
	else if (tmp < 64)
	    bank_cnt=1;		/* one bank per sdram side */
	else if (tmp < 73)
	    bank_cnt=2;	/* need two banks per side */
	else if (tmp < 161)
	    bank_cnt=4;	/* need four banks per side */
	else
	    SPD_ERR("SDRAM - unsupported module width\n");

	/* byte 5 is the module row count (refered to as dimm "sides") */
	tmp = read_spd(5);
	if(tmp==1);
	else if(tmp==2) bank_cnt *=2;
	else if(tmp==4) bank_cnt *=4;
	else bank_cnt = 8; 		/* 8 is an error code */

	if(bank_cnt > 4)	/* we only have 4 banks to work with */
	    SPD_ERR("SDRAM - unsupported module rows for this width\n");

	/* now check for ECC ability of module. We only support ECC
	 *   on 32 bit wide devices with 8 bit ECC.
	 */
	if ( (read_spd(11)==2) && (read_spd(6)==40) && (read_spd(14)==8) ){
	   sdram0_ecccfg=0xf<<SDRAM0_ECCCFG_SHIFT;
	   ecc_on = 1;
   	}
	else{
	   sdram0_ecccfg=0;
	   ecc_on = 0;
   	}

/*------------------------------------------------------------------
	calculate total size
  -------------------------------------------------------------------*/
	/* calculate total size and do sanity check */
	tmp = read_spd(31);
	total_size=1<<22;	/* total_size = 4MB */
	/* now multiply 4M by the smallest device row density */
	/* note that we don't support asymetric rows */
	while (((tmp & 0x0001) == 0) && (tmp != 0)){
	    total_size= total_size<<1;
	    tmp = tmp>>1;
	    }
	total_size *= read_spd(5);	/* mult by module rows (dimm sides) */

/*------------------------------------------------------------------
	map  rows * cols * banks to a mode
 -------------------------------------------------------------------*/

	switch( row )
	{
	case 11:
		switch ( col )
		{
		case 8:
			mode=4; /* mode 5 */
			break;
		case 9:
		case 10:
			mode=0; /* mode 1 */
			break;
		default:
	     	SPD_ERR("SDRAM - unsupported mode\n");
		}
		break;
	case 12:
		switch ( col )
		{
		case 8:
			mode=3; /* mode 4 */
			break;
		case 9:
		case 10:
			mode=1; /* mode 2 */
			break;
		default:
	     	SPD_ERR("SDRAM - unsupported mode\n");
		}
		break;
	case 13:
		switch ( col )
		{
		case 8:
			mode=5; /* mode 6 */
			break;
		case 9:
		case 10:
			if (read_spd(17) ==2 )
				mode=6; /* mode 7 */
			else
				mode=2; /* mode 3 */
			break;
		case 11:
			mode=2; /* mode 3 */
			break;
		default:
	     	SPD_ERR("SDRAM - unsupported mode\n");
		}
		break;
	default:
	     SPD_ERR("SDRAM - unsupported mode\n");
	}

/*------------------------------------------------------------------
	using the calculated values, compute the bank
	config register values.
 -------------------------------------------------------------------*/
	sdram0_b1cr = 0;
	sdram0_b2cr = 0;
	sdram0_b3cr = 0;

	/* compute the size of each bank */
	bank_size = total_size / bank_cnt;
	/* convert bank size to bank size code for ppc4xx
		by takeing log2(bank_size) - 22 */
	tmp=bank_size; 		/* start with tmp = bank_size */
	bank_code=0;			/* and bank_code = 0 */
	while (tmp>1){ 		/* this takes log2 of tmp */
		bank_code++;		/* and stores result in bank_code */
		tmp=tmp>>1;
		}				/* bank_code is now log2(bank_size) */
	bank_code-=22;				/* subtract 22 to get the code */

	tmp = SDRAM0_BXCR_SZ(bank_code) | SDRAM0_BXCR_AM(mode) | 1;
    	sdram0_b0cr = (bank_size) * 0 | tmp;
    	if(bank_cnt>1) sdram0_b2cr = (bank_size) * 1 | tmp;
    	if(bank_cnt>2) sdram0_b1cr = (bank_size) * 2 | tmp;
    	if(bank_cnt>3) sdram0_b3cr = (bank_size) * 3 | tmp;


	/*
	 *   enable sdram controller DCE=1
	 *  enable burst read prefetch to 32 bytes BRPF=2
	 *  leave other functions off
	 */

/*------------------------------------------------------------------
	now that we've done our calculations, we are ready to
	program all the registers.
 -------------------------------------------------------------------*/


#define mtsdram0(reg, data)  mtdcr(memcfga,reg);mtdcr(memcfgd,data)
	/* disable memcontroller so updates work */
	sdram0_cfg = 0;
	mtsdram0( mem_mcopt1, sdram0_cfg );

#ifndef CONFIG_405EP /* not on PPC405EP */
	mtsdram0( mem_besra , sdram0_besr0 );
	mtsdram0( mem_besrb , sdram0_besr1 );
	mtsdram0( mem_ecccf , sdram0_ecccfg );
	mtsdram0( mem_eccerr, sdram0_eccesr );
#endif
	mtsdram0( mem_rtr   , sdram0_rtr );
	mtsdram0( mem_pmit  , sdram0_pmit );
	mtsdram0( mem_mb0cf , sdram0_b0cr );
	mtsdram0( mem_mb1cf , sdram0_b1cr );
	mtsdram0( mem_mb2cf , sdram0_b2cr );
	mtsdram0( mem_mb3cf , sdram0_b3cr );
	mtsdram0( mem_sdtr1 , sdram0_tr );

	/* SDRAM have a power on delay,  500 micro should do */
	udelay(500);
	sdram0_cfg = SDRAM0_CFG_DCE | SDRAM0_CFG_BRPF(1) | SDRAM0_CFG_ECCDD | SDRAM0_CFG_EMDULR;
	if(ecc_on) sdram0_cfg |= SDRAM0_CFG_MEMCHK;
	mtsdram0( mem_mcopt1, sdram0_cfg );


	/* kernel 2.4.2 from mvista has a bug with memory over 128MB */
#ifdef MVISTA_MEM_BUG
	if (total_size > 128*1024*1024 )
		total_size=128*1024*1024;
#endif
	return (total_size);
}

int spd_read(uint addr)
{
	char data[2];

	if (i2c_read(SPD_EEPROM_ADDRESS, addr, 1, data, 1) == 0)
		return (int)data[0];
	else
		return 0;
}

#else                             /* CONFIG_440 */

/*-----------------------------------------------------------------------------
|  Memory Controller Options 0
+-----------------------------------------------------------------------------*/
#define SDRAM_CFG0_DCEN           0x80000000  /* SDRAM Controller Enable      */
#define SDRAM_CFG0_MCHK_MASK      0x30000000  /* Memory data errchecking mask */
#define SDRAM_CFG0_MCHK_NON       0x00000000  /* No ECC generation            */
#define SDRAM_CFG0_MCHK_GEN       0x20000000  /* ECC generation               */
#define SDRAM_CFG0_MCHK_CHK       0x30000000  /* ECC generation and checking  */
#define SDRAM_CFG0_RDEN           0x08000000  /* Registered DIMM enable       */
#define SDRAM_CFG0_PMUD           0x04000000  /* Page management unit         */
#define SDRAM_CFG0_DMWD_MASK      0x02000000  /* DRAM width mask              */
#define SDRAM_CFG0_DMWD_32        0x00000000  /* 32 bits                      */
#define SDRAM_CFG0_DMWD_64        0x02000000  /* 64 bits                      */
#define SDRAM_CFG0_UIOS_MASK      0x00C00000  /* Unused IO State              */
#define SDRAM_CFG0_PDP            0x00200000  /* Page deallocation policy     */

/*-----------------------------------------------------------------------------
|  Memory Controller Options 1
+-----------------------------------------------------------------------------*/
#define SDRAM_CFG1_SRE            0x80000000  /* Self-Refresh Entry           */
#define SDRAM_CFG1_PMEN           0x40000000  /* Power Management Enable      */

/*-----------------------------------------------------------------------------+
|  SDRAM DEVPOT Options
+-----------------------------------------------------------------------------*/
#define SDRAM_DEVOPT_DLL          0x80000000
#define SDRAM_DEVOPT_DS           0x40000000

/*-----------------------------------------------------------------------------+
|  SDRAM MCSTS Options
+-----------------------------------------------------------------------------*/
#define SDRAM_MCSTS_MRSC          0x80000000
#define SDRAM_MCSTS_SRMS          0x40000000
#define SDRAM_MCSTS_CIS           0x20000000

/*-----------------------------------------------------------------------------
|  SDRAM Refresh Timer Register
+-----------------------------------------------------------------------------*/
#define SDRAM_RTR_RINT_MASK       0xFFFF0000
#define SDRAM_RTR_RINT_ENCODE(n)  (((n) << 16) & SDRAM_RTR_RINT_MASK)
#define sdram_HZ_to_ns(hertz)     (1000000000/(hertz))

/*-----------------------------------------------------------------------------+
|  SDRAM UABus Base Address Reg
+-----------------------------------------------------------------------------*/
#define SDRAM_UABBA_UBBA_MASK     0x0000000F

/*-----------------------------------------------------------------------------+
|  Memory Bank 0-7 configuration
+-----------------------------------------------------------------------------*/
#define SDRAM_BXCR_SDBA_MASK      0xff800000      /* Base address             */
#define SDRAM_BXCR_SDSZ_MASK      0x000e0000      /* Size                     */
#define SDRAM_BXCR_SDSZ_8         0x00020000      /*   8M                     */
#define SDRAM_BXCR_SDSZ_16        0x00040000      /*  16M                     */
#define SDRAM_BXCR_SDSZ_32        0x00060000      /*  32M                     */
#define SDRAM_BXCR_SDSZ_64        0x00080000      /*  64M                     */
#define SDRAM_BXCR_SDSZ_128       0x000a0000      /* 128M                     */
#define SDRAM_BXCR_SDSZ_256       0x000c0000      /* 256M                     */
#define SDRAM_BXCR_SDSZ_512       0x000e0000      /* 512M                     */
#define SDRAM_BXCR_SDAM_MASK      0x0000e000      /* Addressing mode          */
#define SDRAM_BXCR_SDAM_1         0x00000000      /*   Mode 1                 */
#define SDRAM_BXCR_SDAM_2         0x00002000      /*   Mode 2                 */
#define SDRAM_BXCR_SDAM_3         0x00004000      /*   Mode 3                 */
#define SDRAM_BXCR_SDAM_4         0x00006000      /*   Mode 4                 */
#define SDRAM_BXCR_SDBE           0x00000001      /* Memory Bank Enable       */

/*-----------------------------------------------------------------------------+
|  SDRAM TR0 Options
+-----------------------------------------------------------------------------*/
#define SDRAM_TR0_SDWR_MASK       0x80000000
#define   SDRAM_TR0_SDWR_2_CLK    0x00000000
#define   SDRAM_TR0_SDWR_3_CLK    0x80000000
#define SDRAM_TR0_SDWD_MASK       0x40000000
#define   SDRAM_TR0_SDWD_0_CLK    0x00000000
#define   SDRAM_TR0_SDWD_1_CLK    0x40000000
#define SDRAM_TR0_SDCL_MASK       0x01800000
#define   SDRAM_TR0_SDCL_2_0_CLK  0x00800000
#define   SDRAM_TR0_SDCL_2_5_CLK  0x01000000
#define   SDRAM_TR0_SDCL_3_0_CLK  0x01800000
#define SDRAM_TR0_SDPA_MASK       0x000C0000
#define   SDRAM_TR0_SDPA_2_CLK    0x00040000
#define   SDRAM_TR0_SDPA_3_CLK    0x00080000
#define   SDRAM_TR0_SDPA_4_CLK    0x000C0000
#define SDRAM_TR0_SDCP_MASK       0x00030000
#define   SDRAM_TR0_SDCP_2_CLK    0x00000000
#define   SDRAM_TR0_SDCP_3_CLK    0x00010000
#define   SDRAM_TR0_SDCP_4_CLK    0x00020000
#define   SDRAM_TR0_SDCP_5_CLK    0x00030000
#define SDRAM_TR0_SDLD_MASK       0x0000C000
#define   SDRAM_TR0_SDLD_1_CLK    0x00000000
#define   SDRAM_TR0_SDLD_2_CLK    0x00004000
#define SDRAM_TR0_SDRA_MASK       0x0000001C
#define   SDRAM_TR0_SDRA_6_CLK    0x00000000
#define   SDRAM_TR0_SDRA_7_CLK    0x00000004
#define   SDRAM_TR0_SDRA_8_CLK    0x00000008
#define   SDRAM_TR0_SDRA_9_CLK    0x0000000C
#define   SDRAM_TR0_SDRA_10_CLK   0x00000010
#define   SDRAM_TR0_SDRA_11_CLK   0x00000014
#define   SDRAM_TR0_SDRA_12_CLK   0x00000018
#define   SDRAM_TR0_SDRA_13_CLK   0x0000001C
#define SDRAM_TR0_SDRD_MASK       0x00000003
#define   SDRAM_TR0_SDRD_2_CLK    0x00000001
#define   SDRAM_TR0_SDRD_3_CLK    0x00000002
#define   SDRAM_TR0_SDRD_4_CLK    0x00000003

/*-----------------------------------------------------------------------------+
|  SDRAM TR1 Options
+-----------------------------------------------------------------------------*/
#define SDRAM_TR1_RDSS_MASK         0xC0000000
#define   SDRAM_TR1_RDSS_TR0        0x00000000
#define   SDRAM_TR1_RDSS_TR1        0x40000000
#define   SDRAM_TR1_RDSS_TR2        0x80000000
#define   SDRAM_TR1_RDSS_TR3        0xC0000000
#define SDRAM_TR1_RDSL_MASK         0x00C00000
#define   SDRAM_TR1_RDSL_STAGE1     0x00000000
#define   SDRAM_TR1_RDSL_STAGE2     0x00400000
#define   SDRAM_TR1_RDSL_STAGE3     0x00800000
#define SDRAM_TR1_RDCD_MASK         0x00000800
#define   SDRAM_TR1_RDCD_RCD_0_0    0x00000000
#define   SDRAM_TR1_RDCD_RCD_1_2    0x00000800
#define SDRAM_TR1_RDCT_MASK         0x000001FF
#define   SDRAM_TR1_RDCT_ENCODE(x)  (((x) << 0) & SDRAM_TR1_RDCT_MASK)
#define   SDRAM_TR1_RDCT_DECODE(x)  (((x) & SDRAM_TR1_RDCT_MASK) >> 0)
#define   SDRAM_TR1_RDCT_MIN        0x00000000
#define   SDRAM_TR1_RDCT_MAX        0x000001FF

/*-----------------------------------------------------------------------------+
|  SDRAM WDDCTR Options
+-----------------------------------------------------------------------------*/
#define SDRAM_WDDCTR_WRCP_MASK       0xC0000000
#define   SDRAM_WDDCTR_WRCP_0DEG     0x00000000
#define   SDRAM_WDDCTR_WRCP_90DEG    0x40000000
#define   SDRAM_WDDCTR_WRCP_180DEG   0x80000000
#define SDRAM_WDDCTR_DCD_MASK        0x000001FF

/*-----------------------------------------------------------------------------+
|  SDRAM CLKTR Options
+-----------------------------------------------------------------------------*/
#define SDRAM_CLKTR_CLKP_MASK       0xC0000000
#define   SDRAM_CLKTR_CLKP_0DEG     0x00000000
#define   SDRAM_CLKTR_CLKP_90DEG    0x40000000
#define   SDRAM_CLKTR_CLKP_180DEG   0x80000000
#define SDRAM_CLKTR_DCDT_MASK       0x000001FF

/*-----------------------------------------------------------------------------+
|  SDRAM DLYCAL Options
+-----------------------------------------------------------------------------*/
#define SDRAM_DLYCAL_DLCV_MASK      0x000003FC
#define   SDRAM_DLYCAL_DLCV_ENCODE(x) (((x)<<2) & SDRAM_DLYCAL_DLCV_MASK)
#define   SDRAM_DLYCAL_DLCV_DECODE(x) (((x) & SDRAM_DLYCAL_DLCV_MASK)>>2)

/*-----------------------------------------------------------------------------+
|  General Definition
+-----------------------------------------------------------------------------*/
#define DEFAULT_SPD_ADDR1   0x53
#define DEFAULT_SPD_ADDR2   0x52
#define ONE_BILLION         1000000000
#define MAXBANKS            4               /* at most 4 dimm banks */
#define MAX_SPD_BYTES       256
#define NUMHALFCYCLES       4
#define NUMMEMTESTS         8
#define NUMMEMWORDS         8
#define MAXBXCR             4
#define TRUE                1
#define FALSE               0

const unsigned long test[NUMMEMTESTS][NUMMEMWORDS] = {
    {0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000,
     0xFFFFFFFF, 0xFFFFFFFF},
    {0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF,
     0x00000000, 0x00000000},
    {0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA,
     0x55555555, 0x55555555},
    {0x55555555, 0x55555555, 0xAAAAAAAA, 0xAAAAAAAA, 0x55555555, 0x55555555,
     0xAAAAAAAA, 0xAAAAAAAA},
    {0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5,
     0x5A5A5A5A, 0x5A5A5A5A},
    {0x5A5A5A5A, 0x5A5A5A5A, 0xA5A5A5A5, 0xA5A5A5A5, 0x5A5A5A5A, 0x5A5A5A5A,
     0xA5A5A5A5, 0xA5A5A5A5},
    {0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55,
     0x55AA55AA, 0x55AA55AA},
    {0x55AA55AA, 0x55AA55AA, 0xAA55AA55, 0xAA55AA55, 0x55AA55AA, 0x55AA55AA,
     0xAA55AA55, 0xAA55AA55}
};


unsigned char spd_read(uchar chip, uint addr);

void get_spd_info(unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks);

void check_mem_type
                 (unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks);

void check_volt_type
                 (unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks);

void program_cfg0(unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks);

void program_cfg1(unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks);

void program_rtr (unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks);

void program_tr0 (unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks);

void program_tr1 (void);

void program_ecc (unsigned long  num_bytes);

unsigned
long  program_bxcr(unsigned long* dimm_populated,
                   unsigned char* iic0_dimm_addr,
                   unsigned long  num_dimm_banks);

/*
 * This function is reading data from the DIMM module EEPROM over the SPD bus
 * and uses that to program the sdram controller.
 *
 * This works on boards that has the same schematics that the IBM walnut has.
 *
 * BUG: Don't handle ECC memory
 * BUG: A few values in the TR register is currently hardcoded
 */

long int spd_sdram(void) {
    unsigned char iic0_dimm_addr[] = SPD_EEPROM_ADDRESS;
    unsigned long dimm_populated[sizeof(iic0_dimm_addr)];
    unsigned long total_size;
    unsigned long cfg0;
    unsigned long mcsts;
    unsigned long num_dimm_banks;               /* on board dimm banks */

    num_dimm_banks = sizeof(iic0_dimm_addr);

	/*
	 * Make sure I2C controller is initialized
	 * before continuing.
	 */
	i2c_init(CFG_I2C_SPEED, CFG_I2C_SLAVE);

    /*
     * Read the SPD information using I2C interface. Check to see if the
     * DIMM slots are populated.
     */
    get_spd_info(dimm_populated, iic0_dimm_addr, num_dimm_banks);

    /*
     * Check the memory type for the dimms plugged.
     */
    check_mem_type(dimm_populated, iic0_dimm_addr, num_dimm_banks);

    /*
     * Check the voltage type for the dimms plugged.
     */
    check_volt_type(dimm_populated, iic0_dimm_addr, num_dimm_banks);

    /*
     * program 440GP SDRAM controller options (SDRAM0_CFG0)
     */
    program_cfg0(dimm_populated, iic0_dimm_addr, num_dimm_banks);

    /*
     * program 440GP SDRAM controller options (SDRAM0_CFG1)
     */
    program_cfg1(dimm_populated, iic0_dimm_addr, num_dimm_banks);

    /*
     * program SDRAM refresh register (SDRAM0_RTR)
     */
    program_rtr(dimm_populated, iic0_dimm_addr, num_dimm_banks);

    /*
     * program SDRAM Timing Register 0 (SDRAM0_TR0)
     */
    program_tr0(dimm_populated, iic0_dimm_addr, num_dimm_banks);

    /*
     * program the BxCR registers to find out total sdram installed
     */
    total_size = program_bxcr(dimm_populated, iic0_dimm_addr,
        num_dimm_banks);

    /*
     * program SDRAM Clock Timing Register (SDRAM0_CLKTR)
     */
    mtsdram(mem_clktr, 0x40000000);

    /*
     * delay to ensure 200 usec has elapsed
     */
    udelay(400);

    /*
     * enable the memory controller
     */
    mfsdram(mem_cfg0, cfg0);
    mtsdram(mem_cfg0, cfg0 | SDRAM_CFG0_DCEN);

    /*
     * wait for SDRAM_CFG0_DC_EN to complete
     */
    while(1) {
        mfsdram(mem_mcsts, mcsts);
        if ((mcsts & SDRAM_MCSTS_MRSC) != 0) {
            break;
        }
    }

    /*
     * program SDRAM Timing Register 1, adding some delays
     */
    program_tr1();

    /*
     * if ECC is enabled, initialize parity bits
     */

	return total_size;
}

unsigned char spd_read(uchar chip, uint addr) {
	unsigned char data[2];

	if (i2c_read(chip, addr, 1, data, 1) == 0)
		return data[0];
	else
		return 0;
}

void get_spd_info(unsigned long*   dimm_populated,
                  unsigned char*   iic0_dimm_addr,
                  unsigned long    num_dimm_banks)
{
    unsigned long dimm_num;
    unsigned long dimm_found;
    unsigned char num_of_bytes;
    unsigned char total_size;

    dimm_found = FALSE;
    for (dimm_num = 0; dimm_num < num_dimm_banks; dimm_num++) {
        num_of_bytes = 0;
        total_size = 0;

        num_of_bytes = spd_read(iic0_dimm_addr[dimm_num], 0);
        total_size = spd_read(iic0_dimm_addr[dimm_num], 1);

        if ((num_of_bytes != 0) && (total_size != 0)) {
            dimm_populated[dimm_num] = TRUE;
            dimm_found = TRUE;
#if 0
            printf("DIMM slot %lu: populated\n", dimm_num);
#endif
        }
        else {
            dimm_populated[dimm_num] = FALSE;
#if 0
            printf("DIMM slot %lu: Not populated\n", dimm_num);
#endif
        }
    }

    if (dimm_found == FALSE) {
        printf("ERROR - No memory installed. Install a DDR-SDRAM DIMM.\n\n");
        hang();
    }
}

void check_mem_type(unsigned long*   dimm_populated,
                    unsigned char*   iic0_dimm_addr,
                    unsigned long    num_dimm_banks)
{
    unsigned long dimm_num;
    unsigned char dimm_type;

    for (dimm_num = 0; dimm_num < num_dimm_banks; dimm_num++) {
        if (dimm_populated[dimm_num] == TRUE) {
            dimm_type = spd_read(iic0_dimm_addr[dimm_num], 2);
            switch (dimm_type) {
            case 7:
#if 0
                printf("DIMM slot %lu: DDR SDRAM detected\n", dimm_num);
#endif
                break;
            default:
                printf("ERROR: Unsupported DIMM detected in slot %lu.\n",
                    dimm_num);
                printf("Only DDR SDRAM DIMMs are supported.\n");
                printf("Replace the DIMM module with a supported DIMM.\n\n");
                hang();
                break;
            }
        }
    }
}


void check_volt_type(unsigned long*   dimm_populated,
                     unsigned char*   iic0_dimm_addr,
                     unsigned long    num_dimm_banks)
{
    unsigned long dimm_num;
    unsigned long voltage_type;

    for (dimm_num = 0; dimm_num < num_dimm_banks; dimm_num++) {
        if (dimm_populated[dimm_num] == TRUE) {
            voltage_type = spd_read(iic0_dimm_addr[dimm_num], 8);
            if (voltage_type != 0x04) {
                printf("ERROR: DIMM %lu with unsupported voltage level.\n",
                    dimm_num);
                hang();
            }
            else {
#if 0
                printf("DIMM %lu voltage level supported.\n", dimm_num);
#endif
            }
            break;
        }
    }
}

void program_cfg0(unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks)
{
    unsigned long dimm_num;
    unsigned long cfg0;
    unsigned long ecc_enabled;
    unsigned char ecc;
    unsigned char attributes;
    unsigned long data_width;
    unsigned long dimm_32bit;
    unsigned long dimm_64bit;

    /*
     * get Memory Controller Options 0 data
     */
    mfsdram(mem_cfg0, cfg0);

    /*
     * clear bits
     */
    cfg0 &= ~(SDRAM_CFG0_DCEN | SDRAM_CFG0_MCHK_MASK |
              SDRAM_CFG0_RDEN | SDRAM_CFG0_PMUD |
              SDRAM_CFG0_DMWD_MASK |
              SDRAM_CFG0_UIOS_MASK | SDRAM_CFG0_PDP);


    /*
     * FIXME: assume the DDR SDRAMs in both banks are the same
     */
    ecc_enabled = TRUE;
    for (dimm_num = 0; dimm_num < num_dimm_banks; dimm_num++) {
        if (dimm_populated[dimm_num] == TRUE) {
            ecc = spd_read(iic0_dimm_addr[dimm_num], 11);
            if (ecc != 0x02) {
                ecc_enabled = FALSE;
            }

            /*
             * program Registered DIMM Enable
             */
            attributes = spd_read(iic0_dimm_addr[dimm_num], 21);
            if ((attributes & 0x02) != 0x00) {
                cfg0 |= SDRAM_CFG0_RDEN;
            }

            /*
             * program DDR SDRAM Data Width
             */
            data_width =
                (unsigned long)spd_read(iic0_dimm_addr[dimm_num],6) +
                (((unsigned long)spd_read(iic0_dimm_addr[dimm_num],7)) << 8);
            if (data_width == 64 || data_width == 72) {
                dimm_64bit = TRUE;
                cfg0 |= SDRAM_CFG0_DMWD_64;
            }
            else if (data_width == 32 || data_width == 40) {
                dimm_32bit = TRUE;
                cfg0 |= SDRAM_CFG0_DMWD_32;
            }
            else {
                printf("WARNING: DIMM with datawidth of %lu bits.\n",
                    data_width);
                printf("Only DIMMs with 32 or 64 bit datawidths supported.\n");
                hang();
            }
            break;
        }
    }

    /*
     * program Memory Data Error Checking
     */
    if (ecc_enabled == TRUE) {
        cfg0 |= SDRAM_CFG0_MCHK_GEN;
    }
    else {
        cfg0 |= SDRAM_CFG0_MCHK_NON;
    }

    /*
     * program Page Management Unit
     */
    cfg0 |= SDRAM_CFG0_PMUD;

    /*
     * program Memory Controller Options 0
     * Note: DCEN must be enabled after all DDR SDRAM controller
     * configuration registers get initialized.
     */
    mtsdram(mem_cfg0, cfg0);
}

void program_cfg1(unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks)
{
    unsigned long cfg1;
    mfsdram(mem_cfg1, cfg1);

    /*
     * Self-refresh exit, disable PM
     */
    cfg1 &= ~(SDRAM_CFG1_SRE | SDRAM_CFG1_PMEN);

    /*
     * program Memory Controller Options 1
     */
    mtsdram(mem_cfg1, cfg1);
}

void program_rtr (unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks)
{
    unsigned long dimm_num;
    unsigned long bus_period_x_10;
    unsigned long refresh_rate = 0;
    unsigned char refresh_rate_type;
    unsigned long refresh_interval;
    unsigned long sdram_rtr;
    PPC440_SYS_INFO sys_info;

    /*
     * get the board info
     */
    get_sys_info(&sys_info);
    bus_period_x_10 = ONE_BILLION / (sys_info.freqPLB / 10);


    for (dimm_num = 0;  dimm_num < num_dimm_banks; dimm_num++) {
        if (dimm_populated[dimm_num] == TRUE) {
            refresh_rate_type = 0x7F & spd_read(iic0_dimm_addr[dimm_num], 12);
            switch (refresh_rate_type) {
            case 0x00:
                refresh_rate = 15625;
                break;
            case 0x011:
                refresh_rate = 15625/4;
                break;
            case 0x02:
                refresh_rate = 15625/2;
                break;
            case 0x03:
                refresh_rate = 15626*2;
                break;
            case 0x04:
                refresh_rate = 15625*4;
                break;
            case 0x05:
                refresh_rate = 15625*8;
                break;
            default:
                printf("ERROR: DIMM %lu, unsupported refresh rate/type.\n",
                    dimm_num);
                printf("Replace the DIMM module with a supported DIMM.\n");
                break;
            }

            break;
        }
    }

    refresh_interval = refresh_rate * 10 / bus_period_x_10;
    sdram_rtr = (refresh_interval & 0x3ff8) <<  16;

    /*
     * program Refresh Timer Register (SDRAM0_RTR)
     */
    mtsdram(mem_rtr, sdram_rtr);
}

void program_tr0 (unsigned long* dimm_populated,
                  unsigned char* iic0_dimm_addr,
                  unsigned long  num_dimm_banks)
{
    unsigned long dimm_num;
    unsigned long tr0;
    unsigned char wcsbc;
    unsigned char t_rp_ns;
    unsigned char t_rcd_ns;
    unsigned char t_ras_ns;
    unsigned long t_rp_clk;
    unsigned long t_ras_rcd_clk;
    unsigned long t_rcd_clk;
    unsigned long t_rfc_clk;
    unsigned long plb_check;
    unsigned char cas_bit;
    unsigned long cas_index;
    unsigned char cas_2_0_available;
    unsigned char cas_2_5_available;
    unsigned char cas_3_0_available;
    unsigned long cycle_time_ns_x_10[3];
    unsigned long tcyc_3_0_ns_x_10;
    unsigned long tcyc_2_5_ns_x_10;
    unsigned long tcyc_2_0_ns_x_10;
    unsigned long tcyc_reg;
    unsigned long bus_period_x_10;
    PPC440_SYS_INFO sys_info;
    unsigned long residue;

    /*
     * get the board info
     */
    get_sys_info(&sys_info);
    bus_period_x_10 = ONE_BILLION / (sys_info.freqPLB / 10);

    /*
     * get SDRAM Timing Register 0 (SDRAM_TR0) and clear bits
     */
    mfsdram(mem_tr0, tr0);
    tr0 &= ~(SDRAM_TR0_SDWR_MASK | SDRAM_TR0_SDWD_MASK |
             SDRAM_TR0_SDCL_MASK | SDRAM_TR0_SDPA_MASK |
             SDRAM_TR0_SDCP_MASK | SDRAM_TR0_SDLD_MASK |
             SDRAM_TR0_SDRA_MASK | SDRAM_TR0_SDRD_MASK);

    /*
     * initialization
     */
    wcsbc = 0;
    t_rp_ns = 0;
    t_rcd_ns = 0;
    t_ras_ns = 0;
    cas_2_0_available = TRUE;
    cas_2_5_available = TRUE;
    cas_3_0_available = TRUE;
    tcyc_2_0_ns_x_10 = 0;
    tcyc_2_5_ns_x_10 = 0;
    tcyc_3_0_ns_x_10 = 0;

    for (dimm_num = 0; dimm_num < num_dimm_banks; dimm_num++) {
        if (dimm_populated[dimm_num] == TRUE) {
            wcsbc = spd_read(iic0_dimm_addr[dimm_num], 15);
            t_rp_ns  = spd_read(iic0_dimm_addr[dimm_num], 27) >> 2;
            t_rcd_ns = spd_read(iic0_dimm_addr[dimm_num], 29) >> 2;
            t_ras_ns = spd_read(iic0_dimm_addr[dimm_num], 30);
            cas_bit = spd_read(iic0_dimm_addr[dimm_num], 18);

            for (cas_index = 0; cas_index < 3; cas_index++) {
                switch (cas_index) {
                case 0:
                    tcyc_reg = spd_read(iic0_dimm_addr[dimm_num], 9);
                    break;
                case 1:
                    tcyc_reg = spd_read(iic0_dimm_addr[dimm_num], 23);
                    break;
                default:
                    tcyc_reg = spd_read(iic0_dimm_addr[dimm_num], 25);
                    break;
                }

                if ((tcyc_reg & 0x0F) >= 10) {
                    printf("ERROR: Tcyc incorrect for DIMM in slot %lu\n",
                        dimm_num);
                    hang();
                }

                cycle_time_ns_x_10[cas_index] =
                    (((tcyc_reg & 0xF0) >> 4) * 10) + (tcyc_reg & 0x0F);
            }

            cas_index = 0;

            if ((cas_bit & 0x80) != 0) {
                cas_index += 3;
            }
            else if ((cas_bit & 0x40) != 0) {
                cas_index += 2;
            }
            else if ((cas_bit & 0x20) != 0) {
                cas_index += 1;
            }

            if (((cas_bit & 0x10) != 0) && (cas_index < 3)) {
                tcyc_3_0_ns_x_10 = cycle_time_ns_x_10[cas_index];
                cas_index++;
            }
            else {
                if (cas_index != 0) {
                    cas_index++;
                }
                cas_3_0_available = FALSE;
            }

            if (((cas_bit & 0x08) != 0) || (cas_index < 3)) {
                tcyc_2_5_ns_x_10 = cycle_time_ns_x_10[cas_index];
                cas_index++;
            }
            else {
                if (cas_index != 0) {
                    cas_index++;
                }
                cas_2_5_available = FALSE;
            }

            if (((cas_bit & 0x04) != 0) || (cas_index < 3)) {
                tcyc_2_0_ns_x_10 = cycle_time_ns_x_10[cas_index];
                cas_index++;
            }
            else {
                if (cas_index != 0) {
                    cas_index++;
                }
                cas_2_0_available = FALSE;
            }

            break;
        }
    }

    /*
     * Program SD_WR and SD_WCSBC fields
     */
    tr0 |= SDRAM_TR0_SDWR_2_CLK;                /* Write Recovery: 2 CLK */
    switch (wcsbc) {
    case 0:
        tr0 |= SDRAM_TR0_SDWD_0_CLK;
        break;
    default:
        tr0 |= SDRAM_TR0_SDWD_1_CLK;
        break;
    }

    /*
     * Program SD_CASL field
     */
    if ((cas_2_0_available == TRUE) &&
        (bus_period_x_10 >= tcyc_2_0_ns_x_10)) {
        tr0 |= SDRAM_TR0_SDCL_2_0_CLK;
    }
    else if((cas_2_5_available == TRUE) &&
        (bus_period_x_10 >= tcyc_2_5_ns_x_10)) {
        tr0 |= SDRAM_TR0_SDCL_2_5_CLK;
    }
    else if((cas_3_0_available == TRUE) &&
        (bus_period_x_10 >= tcyc_3_0_ns_x_10)) {
        tr0 |= SDRAM_TR0_SDCL_3_0_CLK;
    }
    else {
        printf("ERROR: No supported CAS latency with the installed DIMMs.\n");
        printf("Only CAS latencies of 2.0, 2.5, and 3.0 are supported.\n");
        printf("Make sure the PLB speed is within the supported range.\n");
        hang();
    }

    /*
     * Calculate Trp in clock cycles and round up if necessary
     * Program SD_PTA field
     */
    t_rp_clk = sys_info.freqPLB * t_rp_ns / ONE_BILLION;
    plb_check = ONE_BILLION * t_rp_clk / t_rp_ns;
    if (sys_info.freqPLB != plb_check) {
        t_rp_clk++;
    }
    switch ((unsigned long)t_rp_clk) {
    case 0:
    case 1:
    case 2:
        tr0 |= SDRAM_TR0_SDPA_2_CLK;
        break;
    case 3:
        tr0 |= SDRAM_TR0_SDPA_3_CLK;
        break;
    default:
        tr0 |= SDRAM_TR0_SDPA_4_CLK;
        break;
    }

    /*
     * Program SD_CTP field
     */
    t_ras_rcd_clk = sys_info.freqPLB * (t_ras_ns - t_rcd_ns) / ONE_BILLION;
    plb_check = ONE_BILLION * t_ras_rcd_clk / (t_ras_ns - t_rcd_ns);
    if (sys_info.freqPLB != plb_check) {
        t_ras_rcd_clk++;
    }
    switch (t_ras_rcd_clk) {
    case 0:
    case 1:
    case 2:
      tr0 |= SDRAM_TR0_SDCP_2_CLK;
      break;
    case 3:
      tr0 |= SDRAM_TR0_SDCP_3_CLK;
      break;
    case 4:
      tr0 |= SDRAM_TR0_SDCP_4_CLK;
      break;
    default:
      tr0 |= SDRAM_TR0_SDCP_5_CLK;
      break;
    }

    /*
     * Program SD_LDF field
     */
    tr0 |= SDRAM_TR0_SDLD_2_CLK;

    /*
     * Program SD_RFTA field
     * FIXME tRFC hardcoded as 75 nanoseconds
     */
    t_rfc_clk = sys_info.freqPLB / (ONE_BILLION / 75);
    residue = sys_info.freqPLB % (ONE_BILLION / 75);
    if (residue >= (ONE_BILLION / 150)) {
        t_rfc_clk++;
    }
    switch (t_rfc_clk) {
    case 0:
    case 1:
    case 2:
    case 3:
    case 4:
    case 5:
    case 6:
        tr0 |= SDRAM_TR0_SDRA_6_CLK;
        break;
    case 7:
        tr0 |= SDRAM_TR0_SDRA_7_CLK;
        break;
    case 8:
        tr0 |= SDRAM_TR0_SDRA_8_CLK;
        break;
    case 9:
        tr0 |= SDRAM_TR0_SDRA_9_CLK;
        break;
    case 10:
        tr0 |= SDRAM_TR0_SDRA_10_CLK;
        break;
    case 11:
        tr0 |= SDRAM_TR0_SDRA_11_CLK;
        break;
    case 12:
        tr0 |= SDRAM_TR0_SDRA_12_CLK;
        break;
    default:
        tr0 |= SDRAM_TR0_SDRA_13_CLK;
        break;
    }

    /*
     * Program SD_RCD field
     */
    t_rcd_clk = sys_info.freqPLB * t_rcd_ns / ONE_BILLION;
    plb_check = ONE_BILLION * t_rcd_clk / t_rcd_ns;
    if (sys_info.freqPLB != plb_check) {
        t_rcd_clk++;
    }
    switch (t_rcd_clk) {
    case 0:
    case 1:
    case 2:
        tr0 |= SDRAM_TR0_SDRD_2_CLK;
        break;
    case 3:
        tr0 |= SDRAM_TR0_SDRD_3_CLK;
        break;
    default:
        tr0 |= SDRAM_TR0_SDRD_4_CLK;
        break;
    }

#if 0
    printf("tr0: %x\n", tr0);
#endif
    mtsdram(mem_tr0, tr0);
}

void program_tr1 (void)
{
    unsigned long tr0;
    unsigned long tr1;
    unsigned long cfg0;
    unsigned long ecc_temp;
    unsigned long dlycal;
    unsigned long dly_val;
    unsigned long i, j, k;
    unsigned long bxcr_num;
    unsigned long max_pass_length;
    unsigned long current_pass_length;
    unsigned long current_fail_length;
    unsigned long current_start;
    unsigned long rdclt;
    unsigned long rdclt_offset;
    long max_start;
    long max_end;
    long rdclt_average;
    unsigned char window_found;
    unsigned char fail_found;
    unsigned char pass_found;
    unsigned long * membase;
    PPC440_SYS_INFO sys_info;

    /*
     * get the board info
     */
    get_sys_info(&sys_info);

    /*
     * get SDRAM Timing Register 0 (SDRAM_TR0) and clear bits
     */
    mfsdram(mem_tr1, tr1);
    tr1 &= ~(SDRAM_TR1_RDSS_MASK | SDRAM_TR1_RDSL_MASK |
             SDRAM_TR1_RDCD_MASK | SDRAM_TR1_RDCT_MASK);

    mfsdram(mem_tr0, tr0);
    if (((tr0 & SDRAM_TR0_SDCL_MASK) == SDRAM_TR0_SDCL_2_5_CLK) &&
       (sys_info.freqPLB > 100000000)) {
        tr1 |= SDRAM_TR1_RDSS_TR2;
        tr1 |= SDRAM_TR1_RDSL_STAGE3;
        tr1 |= SDRAM_TR1_RDCD_RCD_1_2;
    }
    else {
        tr1 |= SDRAM_TR1_RDSS_TR1;
        tr1 |= SDRAM_TR1_RDSL_STAGE2;
        tr1 |= SDRAM_TR1_RDCD_RCD_0_0;
    }

    /*
     * save CFG0 ECC setting to a temporary variable and turn ECC off
     */
    mfsdram(mem_cfg0, cfg0);
    ecc_temp = cfg0 & SDRAM_CFG0_MCHK_MASK;
    mtsdram(mem_cfg0, (cfg0 & ~SDRAM_CFG0_MCHK_MASK) | SDRAM_CFG0_MCHK_NON);

    /*
     * get the delay line calibration register value
     */
    mfsdram(mem_dlycal, dlycal);
    dly_val = SDRAM_DLYCAL_DLCV_DECODE(dlycal) << 2;

    max_pass_length = 0;
    max_start = 0;
    max_end = 0;
    current_pass_length = 0;
    current_fail_length = 0;
    current_start = 0;
    rdclt_offset = 0;
    window_found = FALSE;
    fail_found = FALSE;
    pass_found = FALSE;
#ifdef DEBUG
    printf("Starting memory test ");
#endif
    for (k = 0; k < NUMHALFCYCLES; k++) {
        for (rdclt = 0; rdclt < dly_val; rdclt++)  {
            /*
             * Set the timing reg for the test.
             */
            mtsdram(mem_tr1, (tr1 | SDRAM_TR1_RDCT_ENCODE(rdclt)));

            for (bxcr_num = 0; bxcr_num < MAXBXCR; bxcr_num++) {
                mtdcr(memcfga, mem_b0cr + (bxcr_num<<2));
                if ((mfdcr(memcfgd) & SDRAM_BXCR_SDBE) == SDRAM_BXCR_SDBE) {
                    /* Bank is enabled */
                    membase = (unsigned long*)
                        (mfdcr(memcfgd) & SDRAM_BXCR_SDBA_MASK);

                    /*
                     * Run the short memory test
                     */
                    for (i = 0; i < NUMMEMTESTS; i++) {
                        for (j = 0; j < NUMMEMWORDS; j++) {
                            membase[j] = test[i][j];
                            ppcDcbf((unsigned long)&(membase[j]));
                        }

                        for (j = 0; j < NUMMEMWORDS; j++) {
                            if (membase[j] != test[i][j]) {
                                ppcDcbf((unsigned long)&(membase[j]));
                                break;
                            }
                            ppcDcbf((unsigned long)&(membase[j]));
                        }

                        if (j < NUMMEMWORDS) {
                            break;
                        }
                    }

                    /*
                     * see if the rdclt value passed
                     */
                    if (i < NUMMEMTESTS) {
                        break;
                    }
                }
            }

            if (bxcr_num == MAXBXCR) {
                if (fail_found == TRUE) {
                    pass_found = TRUE;
                    if (current_pass_length == 0) {
                        current_start = rdclt_offset + rdclt;
                    }

                    current_fail_length = 0;
                    current_pass_length++;

                    if (current_pass_length > max_pass_length) {
                        max_pass_length = current_pass_length;
                        max_start = current_start;
                        max_end = rdclt_offset + rdclt;
                    }
                }
            }
            else {
                current_pass_length = 0;
                current_fail_length++;

                if (current_fail_length >= (dly_val>>2)) {
                    if (fail_found == FALSE) {
                        fail_found = TRUE;
                    }
                    else if (pass_found == TRUE) {
                        window_found = TRUE;
                        break;
                    }
                }
            }
        }
#ifdef DEBUG
        printf(".");
#endif
        if (window_found == TRUE) {
            break;
        }

        tr1 = tr1 ^ SDRAM_TR1_RDCD_MASK;
        rdclt_offset += dly_val;
    }
#ifdef DEBUG
    printf("\n");
#endif

    /*
     * make sure we find the window
     */
    if (window_found == FALSE) {
       printf("ERROR: Cannot determine a common read delay.\n");
       hang();
    }

    /*
     * restore the orignal ECC setting
     */
    mtsdram(mem_cfg0, (cfg0 & ~SDRAM_CFG0_MCHK_MASK) | ecc_temp);

    /*
     * set the SDRAM TR1 RDCD value
     */
    tr1 &= ~SDRAM_TR1_RDCD_MASK;
    if ((tr0 & SDRAM_TR0_SDCL_MASK) == SDRAM_TR0_SDCL_2_5_CLK) {
        tr1 |= SDRAM_TR1_RDCD_RCD_1_2;
    }
    else {
        tr1 |= SDRAM_TR1_RDCD_RCD_0_0;
    }

    /*
     * set the SDRAM TR1 RDCLT value
     */
    tr1 &= ~SDRAM_TR1_RDCT_MASK;
    while (max_end >= (dly_val<<1)) {
        max_end -= (dly_val<<1);
        max_start -= (dly_val<<1);
    }

    rdclt_average = ((max_start + max_end) >> 1);
    if (rdclt_average >= 0x60)
        while(1);

    if (rdclt_average < 0) {
        rdclt_average = 0;
    }

    if (rdclt_average >= dly_val) {
        rdclt_average -= dly_val;
        tr1 = tr1 ^ SDRAM_TR1_RDCD_MASK;
    }
    tr1 |= SDRAM_TR1_RDCT_ENCODE(rdclt_average);

#if 0
    printf("tr1: %x\n", tr1);
#endif
    /*
     * program SDRAM Timing Register 1 TR1
     */
    mtsdram(mem_tr1, tr1);
}

unsigned long program_bxcr(unsigned long* dimm_populated,
                           unsigned char* iic0_dimm_addr,
                           unsigned long  num_dimm_banks)
{
    unsigned long dimm_num;
    unsigned long bxcr_num;
    unsigned long bank_base_addr;
    unsigned long bank_size_bytes;
    unsigned long cr;
    unsigned long i;
    unsigned long temp;
    unsigned char num_row_addr;
    unsigned char num_col_addr;
    unsigned char num_banks;
    unsigned char bank_size_id;


    /*
     * Set the BxCR regs.  First, wipe out the bank config registers.
     */
    for (bxcr_num = 0; bxcr_num < MAXBXCR; bxcr_num++) {
        mtdcr(memcfga, mem_b0cr + (bxcr_num << 2));
        mtdcr(memcfgd, 0x00000000);
    }

    /*
     * reset the bank_base address
     */
    bank_base_addr = CFG_SDRAM_BASE;

    for (dimm_num = 0; dimm_num < num_dimm_banks; dimm_num++) {
        if (dimm_populated[dimm_num] == TRUE) {
            num_row_addr = spd_read(iic0_dimm_addr[dimm_num], 3);
            num_col_addr = spd_read(iic0_dimm_addr[dimm_num], 4);
            num_banks    = spd_read(iic0_dimm_addr[dimm_num], 5);
            bank_size_id = spd_read(iic0_dimm_addr[dimm_num], 31);

            /*
             * Set the SDRAM0_BxCR regs
             */
            cr = 0;
            bank_size_bytes = 4 * 1024 * 1024 * bank_size_id;
            switch (bank_size_id) {
            case 0x02:
                cr |= SDRAM_BXCR_SDSZ_8;
                break;
            case 0x04:
                cr |= SDRAM_BXCR_SDSZ_16;
                break;
            case 0x08:
                cr |= SDRAM_BXCR_SDSZ_32;
                break;
            case 0x10:
                cr |= SDRAM_BXCR_SDSZ_64;
                break;
            case 0x20:
                cr |= SDRAM_BXCR_SDSZ_128;
                break;
            case 0x40:
                cr |= SDRAM_BXCR_SDSZ_256;
                break;
            case 0x80:
                cr |= SDRAM_BXCR_SDSZ_512;
                break;
            default:
                printf("DDR-SDRAM: DIMM %lu BxCR configuration.\n",
                    dimm_num);
                printf("ERROR: Unsupported value for the banksize: %d.\n",
                   bank_size_id);
                printf("Replace the DIMM module with a supported DIMM.\n\n");
                hang();
            }

            switch (num_col_addr) {
            case 0x08:
                cr |= SDRAM_BXCR_SDAM_1;
                break;
            case 0x09:
                cr |= SDRAM_BXCR_SDAM_2;
                break;
            case 0x0A:
                cr |= SDRAM_BXCR_SDAM_3;
                break;
            case 0x0B:
                cr |= SDRAM_BXCR_SDAM_4;
                break;
            default:
                printf("DDR-SDRAM: DIMM %lu BxCR configuration.\n",
                   dimm_num);
                printf("ERROR: Unsupported value for number of "
                   "column addresses: %d.\n", num_col_addr);
                printf("Replace the DIMM module with a supported DIMM.\n\n");
                hang();
            }

            /*
             * enable the bank
             */
            cr |= SDRAM_BXCR_SDBE;

            /*------------------------------------------------------------------
            | This next section is hardware dependent and must be programmed
            | to match the hardware.
            +-----------------------------------------------------------------*/
            if (dimm_num == 0) {
                for (i = 0; i < num_banks; i++) {
                    mtdcr(memcfga, mem_b0cr + (i << 2));
                    temp = mfdcr(memcfgd) & ~(SDRAM_BXCR_SDBA_MASK |
                                              SDRAM_BXCR_SDSZ_MASK |
                                              SDRAM_BXCR_SDAM_MASK |
                                              SDRAM_BXCR_SDBE);
                    cr |= temp;
                    cr |= bank_base_addr & SDRAM_BXCR_SDBA_MASK;
                    mtdcr(memcfgd, cr);
                    bank_base_addr += bank_size_bytes;
                }
            }
            else {
                for (i = 0; i < num_banks; i++) {
                    mtdcr(memcfga, mem_b2cr + (i << 2));
                    temp = mfdcr(memcfgd) & ~(SDRAM_BXCR_SDBA_MASK |
                                              SDRAM_BXCR_SDSZ_MASK |
                                              SDRAM_BXCR_SDAM_MASK |
                                              SDRAM_BXCR_SDBE);
                    cr |= temp;
                    cr |= bank_base_addr & SDRAM_BXCR_SDBA_MASK;
                    mtdcr(memcfgd, cr);
                    bank_base_addr += bank_size_bytes;
                }
            }
        }
    }

    return(bank_base_addr);
}

void program_ecc (unsigned long  num_bytes)
{
    unsigned long bank_base_addr;
    unsigned long current_address;
    unsigned long end_address;
    unsigned long address_increment;
    unsigned long cfg0;

    /*
     * get Memory Controller Options 0 data
     */
    mfsdram(mem_cfg0, cfg0);

    /*
     * reset the bank_base address
     */
    bank_base_addr = CFG_SDRAM_BASE;

    if ((cfg0 & SDRAM_CFG0_MCHK_MASK) != SDRAM_CFG0_MCHK_NON) {
        mtsdram(mem_cfg0, (cfg0 & ~SDRAM_CFG0_MCHK_MASK) |
            SDRAM_CFG0_MCHK_GEN);

        if ((cfg0 & SDRAM_CFG0_DMWD_MASK) == SDRAM_CFG0_DMWD_32) {
            address_increment = 4;
        }
        else {
            address_increment = 8;
        }

        current_address = (unsigned long)(bank_base_addr);
        end_address = (unsigned long)(bank_base_addr) + num_bytes;

        while (current_address < end_address) {
            *((unsigned long*)current_address) = 0x00000000;
            current_address += address_increment;
        }

        mtsdram(mem_cfg0, (cfg0 & ~SDRAM_CFG0_MCHK_MASK) |
            SDRAM_CFG0_MCHK_CHK);
    }
}

#endif /* CONFIG_440 */

#endif /* CONFIG_SPD_EEPROM */