Initial revision

1 files changed, 1764 insertions, 0 deletions

diff --git a/cpu/ppc4xx/spd_sdram.c b/cpu/ppc4xx/spd_sdram.c
new file mode 100644
index 0000000000..fc0c980c73
--- /dev/null
+++ b/cpu/ppc4xx/spd_sdram.c
@@ -0,0 +1,1764 @@
+/*
+ * (C) Copyright 2001
+ * Bill Hunter, Wave 7 Optics, williamhunter@attbi.com
+ *
+ * Based on code by:
+ *
+ * Kenneth Johansson ,Ericsson Business Innovation.
+ * kenneth.johansson@inn.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_W7O
+# define SPD_ERR(x) do { return 0; } while (0)
+#else
+# define SPD_ERR(x) do { printf(x); hang(); } while (0)
+#endif
+
+/*
+ * what we really want is
+ * (1/hertz) but we don't want to use floats so multiply with 10E9
+ *
+ * The error needs to be on the safe side so we want the floor function.
+ * This means we get an exact value or we calculate that our bus frequency is
+ * a bit faster than it really is and thus we don't progam the sdram controller
+ * to run to fast
+ */
+#define sdram_HZ_to_ns(hertz) (1000000000/(hertz))
+
+/* function prototypes */
+int spd_read(uint addr);			/* prototype */
+
+
+/*
+ * 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)
+{
+	int bus_period,tmp,row,col;
+	int total_size,bank_size,bank_code;
+	int ecc_on;
+	int mode = 4;
+	int bank_cnt = 1;
+
+	int sdram0_pmit=0x07c00000;
+	int sdram0_besr0=-1;
+	int sdram0_besr1=-1;
+	int sdram0_eccesr=-1;
+	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_rc = 70; /* This value not available in SPD_EEPROM */
+	int min_cas = 2;
+
+	/*
+	 * 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.
+	 */
+    	tmp = (mfdcr(pllmd) >> (31-6)) & 0xf;	/* get FBDV bits */
+	tmp = CONFIG_SYS_CLK_FREQ * tmp;	/* get plb freq */
+	bus_period = sdram_HZ_to_ns(tmp);	/* get sdram speed */
+
+     	/* Make shure we are using SDRAM */
+	if (spd_read(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 = spd_read(127) & 0x6;
+     if(tmp == 0x02){      	   /* only cas = 2 supported */
+     	  min_cas = 2;
+/*     	  t_ck = spd_read(9); */
+/*     	  t_ac = spd_read(10); */
+	  }
+     else if (tmp == 0x04){         /* only cas = 3 supported */
+     	  min_cas = 3;
+/*     	  t_ck = spd_read(9); */
+/*     	  t_ac = spd_read(10); */
+	  }
+     else if (tmp == 0x06){         /* 2,3 supported, so use 2 */
+     	  min_cas = 2;
+/*     	  t_ck = spd_read(23); */
+/*     	  t_ac = spd_read(24); */
+	  }
+     else {
+	     SPD_ERR("SDRAM - unsupported CAS latency \n");
+	}
+
+     /* get some timing values, t_rp,t_rcd
+     */
+     t_rp = spd_read(27);
+     t_rcd = spd_read(29);
+
+
+     /* The following timing calcs subtract 1 before deviding.
+      * this has effect of using ceiling intead 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) SPD_ERR("SDRAM - unsupported prech to act time (Trp)\n");
+     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)-4;
+	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 = spd_read(3);
+     col = spd_read(4);
+     tmp = spd_read(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(spd_read(7) != 0)
+	    SPD_ERR("SDRAM - unsupported module width\n");
+	tmp = spd_read(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 = spd_read(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 ( (spd_read(11)==2) && ((spd_read(6)==40) || (spd_read(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 = spd_read(31);
+	total_size=1<<22;	/* total_size = 4MB */
+	/* now multiply 4M by the smallest device roe 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 *= spd_read(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 (spd_read(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 );
+
+	mtsdram0( mem_besra , sdram0_besr0 );
+	mtsdram0( mem_besrb , sdram0_besr1 );
+	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 );
+	mtsdram0( mem_ecccf , sdram0_ecccfg );
+	mtsdram0( mem_eccerr, sdram0_eccesr );
+
+	/* 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 */