board/mpc7448hpc2/asm_init.S

/*****************************************************************************
 * (C) Copyright 2004-05;  Tundra Semiconductor Corp.
 * 
 * Added automatic detect of SDC settings
 * Copyright (c) 2005 Freescale Semiconductor, Inc.
 * Maintainer tie-fei.zang@freescale.com
 * 
 * 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
 ****************************************************************************/

/*----------------------------------------------------------------------------
 * FILENAME: asm_init.s
 *
 * Originator: Alex Bounine
 *
 * DESCRIPTION:
 * Initialization code for the Tundra Tsi108 bridge chip
 *
 *---------------------------------------------------------------------------*/

#include <config.h>
#include <version.h>

#include <ppc_asm.tmpl>
#include <ppc_defs.h>
#include <asm/processor.h>

#include <tsi108.h>

/*===========================================================================
 * Build Configuration Options
 */

/* #define DISABLE_PBM       disables usage of PB Master */
/* #define SDC_HARDCODED_INIT  config SDRAM controller with hardcoded values */
/* #define SDC_AUTOPRECH_EN    enable SDRAM auto precharge */

/* ===========================================================================
 * Hardcoded SDC settings
 */

#ifdef SDC_HARDCODED_INIT

/* Micron MT9HTF6472AY-40EA1 : Unbuffered, 512MB, 400, CL3, Single Rank */

#define VAL_SD_REFRESH  (0x61A)
#define VAL_SD_TIMING   (0x0308336b)
#define VAL_SD_D0_CTRL  (0x07100021) /* auto-precharge disabled */
#define VAL_SD_D0_BAR   (0x0FE00000) /* 512MB @ 0x00000000 */
#define VAL_SD_D1_CTRL  (0x07100021) /* auto-precharge disabled */
#define VAL_SD_D1_BAR   (0x0FE00200) /* 512MB @ 0x20000000 */

#endif /* SDC_HARDCODED_INIT */

/*---------------------------------------------------------------------------
 CPU Configuration:

 CPU Address and Data Parity enables.

#define CPU_AP
#define CPU_DP

===========================================================================
 Macros

 !!! Attention !!! Macros LOAD_PTR, LOAD_U32 and LOAD_MEM defined below are
 expected to work correctly for the CSR space within 32KB range.

 LOAD_PTR and LOAD_U32 - load specified register with a 32 bit constant.
 These macros are absolutely identical except their names. This difference
 is provided intentionally for better readable code.
 -------------------------------------------------------------------------*/

#define LOAD_PTR(reg,const32) \
      addis reg,r0,const32@h; ori reg,reg,const32@l

#define LOAD_U32(reg,const32) \
      addis reg,r0,const32@h; ori reg,reg,const32@l

/* LOADMEM initializes a register with the contents of a specified 32-bit memory
 location, usually a CSR value.*/

#define LOAD_MEM(reg,addr32) \
      addis reg,r0,addr32@ha; lwz reg,addr32@l(reg)

#ifndef SDC_HARDCODED_INIT
sdc_clk_sync:
	/* MHz: 0,0,183,100,133,167,200,233 */
	.long	0,0,  6, 10,  8,  6,  5,  4  /* nSec */
#endif

/*===========================================================================
 board_asm_init() - early initialization function. Coded to be portable to
                    dual-CPU configuration.
 Checks CPU number and performs board HW initialization if called for CPU0.

 Registers used: r3,r4,r5,r6,r19,r29
===========================================================================

---------------------------------------------------------------------------
 NOTE: For dual-CPU configuration only CPU0 is allowed to configure Tsi108
       and the rest of the board. Current implementation demonstrates two
       possible ways to identify CPU number:
        - for MPC74xx platform: uses MSSCR0[ID] bit as defined in UM.
        - for PPC750FX/GX boards: uses WHO_AM_I bit reported by Tsi108.
---------------------------------------------------------------------------*/

    .globl board_asm_init
board_asm_init:

    mflr    r19          /* Save LR to be able return later. */

    bl icache_enable     /* Enable icache to reduce reads from flash. */

    /* Initialize pointer to Tsi108 register space
    -------------------------------------------------------------------------*/

    LOAD_PTR(r29,CFG_TSI108_CSR_RST_BASE)/* r29 - pointer to tsi108 CSR space */
    ori r4,r29,TSI108_PB_REG_OFFSET

    /*-------------------------------------------------------------------------
     Check Processor Version Number */

    mfspr   r3, PVR
    rlwinm  r3,r3,16,16,23  /* get ((Processor Version Number) & 0xFF00) */

    cmpli   0,0,r3,0x8000   /* MPC74xx */
    bne     cont_brd_init

    /* ------------------------------------------
     For MPC744x/5x enable extended BATs[4-7]
     Sri: Set HIGH_BAT_EN and XBSEN, and SPD =1
          to disable prefetch 
     */

    mfspr   r5, HID0
    oris    r5, r5, 0x0080  /* Set HID0[HIGH_BAT_EN] bit #8 */
    ori     r5, r5, 0x0380    /* Set SPD,XBSEN,SGE bits #22,23,24 */
    mtspr   HID0, r5
    isync
    sync

    /* Adding code to disable external interventions in MPX bus mode */
    mfspr   r3, 1014
    oris    r3, r3, 0x0100 /* Set the EIDIS bit in MSSCR0:  bit 7 */
    mtspr   1014, r3
    isync
    sync

    /* Sri: code to enable FP unit */
    mfmsr   r3
    ori     r3, r3, 0x2000
    mtmsr   r3
    isync
    sync

#if(1) /* def CONFIG_DUAL_CPU
    -------------------------------------------------------------------------
     For MPC74xx processor, use MSSCR0[ID] bit to identify CPU number.
     */

    mfspr   r3,1014         /* read MSSCR0 */
    rlwinm. r3,r3,27,31,31  /* get processor ID number */
    mtspr   SPRN_PIR,r3     /* Save CPU ID */
    sync
    bne init_done
    b do_tsi108_init

cont_brd_init:

    /* An alternative method of checking the processor number (in addition
       to configuration using MSSCR0[ID] bit on MPC74xx). 
       Good for IBM PPC750FX/GX.
     */

    lwz r3,PB_BUS_MS_SELECT(r4) /* read PB_ID register */
    rlwinm. r3,r3,24,31,31      /* get processor ID number */

    bne init_done

#else

cont_brd_init:

#endif /* CONFIG_DUAL_CPU */

    /* Initialize Tsi108 chip
    ---------------------------------------------------------------------------
     */

do_tsi108_init:

    /*--------------------------------------------------------------------------
     Adjust HLP/Flash parameters. By default after reset the HLP port is set
     to support slow devices. Better performance can be achived when an optimal
     parameters are used for specific EPROM device.
     NOTE: This should be performed ASAP for the emulation platform because
     it has 5MHz HLP clocking.
     */

#ifdef CONFIG_TSI108EMU
    ori r4,r29,TSI108_HLP_REG_OFFSET
    LOAD_U32(r5,0x434422c0)
    stw r5,0x08(r4)            /* set HLP B0_CTRL0 */
    sync
    LOAD_U32(r5,0xd0012000)
    stw r5,0x0c(r4)            /* set HLP B0_CTRL1 */
    sync
#endif

    /* -------------------------------------------------------------------------
     * Initialize PB interface.
     */

    ori r4,r29,TSI108_PB_REG_OFFSET

#if (CFG_TSI108_CSR_BASE != CFG_TSI108_CSR_RST_BASE)
    /* Relocate (if required) Tsi108 registers. Set new value for PB_REG_BAR:
     * Note we are in the 32-bit address mode.
     */
    LOAD_U32(r5,(CFG_TSI108_CSR_BASE | 0x01)) /* value for PB_REG_BAR: BA + EN*/
    stw r5,PB_REG_BAR(r4)
    andis. r29,r5,0xFFFF
    sync

    ori r4,r29,TSI108_PB_REG_OFFSET
#endif

    /* Set PB Slave configuration register */

/*    LOAD_U32(r5,0x000024C7)  value for PB_SCR: TEA enabled,AACK delay = 7 */
    LOAD_U32(r5,0x00002481) /* value for PB_SCR: TEA enabled,AACK delay = 1 */
    lwz r3, PB_RSR(r4)      /* get PB bus mode */
    xori r3,r3,0x0001       /* mask PB_BMODE: r3 -> (0 = 60X, 1 = MPX) */
    rlwimi  r5,r3,14,17,17  /* for MPX: set DTI_MODE bit */
    stw r5,PB_SCR(r4)
    sync

    /* Configure PB Arbiter */

    lwz r5,PB_ARB_CTRL(r4)      /* Read PB Arbiter Control Register */
    li r3, 0x00F0               /* ARB_PIPELINE_DEP mask */
#ifdef DISABLE_PBM
    ori r3,r3,0x1000            /* add PBM_EN to clear (enabled by default) */
#endif
    andc r5,r5,r3               /* Clear the masked bit fields */
/*    ori r5,r5,0x0040             Set pipeline depth 4
    ori r5,r5,0x0080             Set pipeline depth 8
    ori r5,r5,0x0020            !!!avb Testing: set pipeline depth 2 */
    ori r5,r5,0x0001
    stw r5,PB_ARB_CTRL(r4)

#if (0) /* currently using the default settings for PBM after reset */
    LOAD_U32(r5,0x) /* value for PB_MCR */
    stw r5,PB_MCR(r4)
    sync

    LOAD_U32(r5,0x) /* value for PB_MCMD */
    stw r5,PB_MCMD(r4)
    sync
#endif

/* Disable or enable PVT based on processor bus frequency
   1. Read CG_PWRUP_STATUS register field bits 18,17,16
   2. See if the value is < or > 133mhz (18:16 = 100)
   3. If > enable PVT 
   */

    LOAD_U32(r3,0xC0002234)
    lwz  r3,0(r3)
    rlwinm  r3,r3,16,29,31

    cmpi 0,0,r3,0x0004
    bgt sdc_init

#ifndef CONFIG_TSI108EMU
   /* FIXME:    Disable PB calibration control for any real Tsi108 board */
    li  r5,0x0101 /* disable calibration control */
    stw r5,PB_PVT_CTRL2(r4)
    sync
#endif

/*---------------------------------------------------------------------------
 Initialize SDRAM controller.
----------------------------------------------------------------------------*/

sdc_init:

#ifndef SDC_HARDCODED_INIT
    /* get SDC clock prior doing sdram controller autoconfig */
    ori r4,r29,TSI108_CLK_REG_OFFSET	/* r4 - ptr to CG registers */
    lwz r3, CG_PWRUP_STATUS(r4)		/* get CG configuration */
    rlwinm r3,r3,12,29,31			/* r3 - SD clk */
    lis r5,sdc_clk_sync@h
    ori r5,r5,sdc_clk_sync@l
       /* Sri:  At this point check if r3 = 001. If yes,
        * the memory frequency should be same as the 
        * MPX bus frequency
        */
    cmpi 0,0,r3,0x0001
    bne get_nsec
    lwz r6, CG_PWRUP_STATUS(r4)
    rlwinm r6,r6,16,29,31
    mr r3,r6

get_nsec:
    rlwinm r3,r3,2,0,31
    lwzx r9,r5,r3	/* get SD clk rate in nSec */
       /* ATTN: r9 will be used by SPD routine */
#endif /* !SDC_HARDCODED_INIT */

    ori r4,r29,TSI108_SD_REG_OFFSET /* r4 - ptr to SDRAM registers */

    /* Initialize SDRAM controller. SDRAM Size = 512MB, One DIMM. */

    LOAD_U32(r5,0x00)
    stw r5,SD_INT_ENABLE(r4)    /* Ensure that interrupts are disabled */
#ifdef ENABLE_SDRAM_ECC
    li r5, 0x01
#endif /* ENABLE_SDRAM_ECC */
    stw r5,SD_ECC_CTRL(r4)      /* Enable/Disable ECC */
    sync

#ifdef SDC_HARDCODED_INIT /* config sdram controller with hardcoded values */

    /* First read the CG_PWRUP_STATUS register to get the
       memory speed from bits 22,21,20 */

    LOAD_U32(r3,0xC0002234)
    lwz  r3,0(r3)
    rlwinm  r3,r3,12,29,31

    /* Now first check for 166, then 200, or default */

    cmpi 0,0,r3,0x0005
    bne check_for_200mhz

    /* set values for 166 Mhz memory speed */

    /* Set refresh rate and timing parameters */
    LOAD_U32(r5,0x00000515)
    stw r5,SD_REFRESH(r4)
    LOAD_U32(r5,0x03073368)
    stw r5,SD_TIMING(r4)
    sync

    /* Initialize DIMM0 control and BAR registers */
    LOAD_U32(r5,VAL_SD_D0_CTRL)   /* auto-precharge disabled */
#ifdef SDC_AUTOPRECH_EN
    oris r5,r5,0x0001   /* set auto precharge EN bit */
#endif
    stw r5,SD_D0_CTRL(r4)
    LOAD_U32(r5,VAL_SD_D0_BAR)
    stw r5,SD_D0_BAR(r4)
    sync

    /* Initialize DIMM1 control and BAR registers
     *  (same as dimm 0, next 512MB, disabled)
     */
    LOAD_U32(r5,VAL_SD_D1_CTRL)  /* auto-precharge disabled */
#ifdef SDC_AUTOPRECH_EN
    oris r5,r5,0x0001   /* set auto precharge EN bit */
#endif
    stw r5,SD_D1_CTRL(r4)
    LOAD_U32(r5,VAL_SD_D1_BAR)
    stw r5,SD_D1_BAR(r4)
    sync

    b sdc_init_done

check_for_200mhz:

    cmpi 0,0,r3,0x0006
    bne set_default_values

    /* set values for 200Mhz memory speed */

    /* Set refresh rate and timing parameters */
    LOAD_U32(r5,0x0000061a)
    stw r5,SD_REFRESH(r4)
    LOAD_U32(r5,0x03083348)
    stw r5,SD_TIMING(r4)
    sync

    /* Initialize DIMM0 control and BAR registers */
    LOAD_U32(r5,VAL_SD_D0_CTRL)   /* auto-precharge disabled */
#ifdef SDC_AUTOPRECH_EN
    oris r5,r5,0x0001   /* set auto precharge EN bit */
#endif
    stw r5,SD_D0_CTRL(r4)
    LOAD_U32(r5,VAL_SD_D0_BAR)
    stw r5,SD_D0_BAR(r4)
    sync

    /* Initialize DIMM1 control and BAR registers
     *  (same as dimm 0, next 512MB, disabled)
     */
    LOAD_U32(r5,VAL_SD_D1_CTRL)  /* auto-precharge disabled */
#ifdef SDC_AUTOPRECH_EN
    oris r5,r5,0x0001   /* set auto precharge EN bit */
#endif
    stw r5,SD_D1_CTRL(r4)
    LOAD_U32(r5,VAL_SD_D1_BAR)
    stw r5,SD_D1_BAR(r4)
    sync

    b sdc_init_done

set_default_values:

    /* Set refresh rate and timing parameters */
    LOAD_U32(r5,VAL_SD_REFRESH)
    stw r5,SD_REFRESH(r4)
    LOAD_U32(r5,VAL_SD_TIMING)
    stw r5,SD_TIMING(r4)
    sync

    /* Initialize DIMM0 control and BAR registers */
    LOAD_U32(r5,VAL_SD_D0_CTRL)   /* auto-precharge disabled */
#ifdef SDC_AUTOPRECH_EN
    oris r5,r5,0x0001   /* set auto precharge EN bit */
#endif
    stw r5,SD_D0_CTRL(r4)
    LOAD_U32(r5,VAL_SD_D0_BAR)
    stw r5,SD_D0_BAR(r4)
    sync

    /* Initialize DIMM1 control and BAR registers
     *  (same as dimm 0, next 512MB, disabled)
     */
    LOAD_U32(r5,VAL_SD_D1_CTRL)  /* auto-precharge disabled */
#ifdef SDC_AUTOPRECH_EN
    oris r5,r5,0x0001   /* set auto precharge EN bit */
#endif
    stw r5,SD_D1_CTRL(r4)
    LOAD_U32(r5,VAL_SD_D1_BAR)
    stw r5,SD_D1_BAR(r4)
    sync

#else /* !SDC_HARDCODED_INIT */
        
    bl tsi108_sdram_spd 	/* automatically detect SDC settings */
     
#endif /* SDC_HARDCODED_INIT */

sdc_init_done:

#ifdef DISABLE_PBM
    LOAD_U32(r5,0x00000030)     /* PB_EN + OCN_EN */
#else
    LOAD_U32(r5,0x00000230)     /* PB_EN + OCN_EN + PB/OCN=80/20 */
#endif /* DISABLE_PBM */

#ifdef CONFIG_TSI108EMU
    oris r5,r5,0x0010   /* set EMULATION_MODE bit */
#endif

    stw r5,SD_CTRL(r4)
    eieio
    sync

    /* Enable SDRAM access */

    oris r5,r5,0x8000   /* start SDC: set SD_CTRL[ENABLE] bit */
    stw r5,SD_CTRL(r4)
    sync

wait_init_complete:
    lwz r5,SD_STATUS(r4)
    andi.   r5,r5,0x0001
    beq wait_init_complete  /* wait until SDRAM initialization is complete */

/*---------------------------------------------------------------------------
 Map SDRAM into the processor bus address space
---------------------------------------------------------------------------*/

    ori r4,r29,TSI108_PB_REG_OFFSET

    /* Setup BARs associated with direct path PB<->SDRAM */

    /* PB_SDRAM_BAR1:
       provides a direct path to the main system memory (cacheable SDRAM) */

    LOAD_U32(r5, 0x00000011)  /* BA=0,Size=512MB, ENable, No Addr.Translation */
    stw r5,PB_SDRAM_BAR1(r4)
    sync

    /* Make sure that PB_SDRAM_BAR1 decoder is set
       (to allow following immediate read from SDRAM) */
    lwz r5,PB_SDRAM_BAR1(r4)
    sync

    /* PB_SDRAM_BAR2:
       provides non-cacheable alias (via the direct path) to main system memory.
       Size = 512MB, ENable, Addr.Translation - ON,
       BA = 0x0_40000000, TA = 0x0_00000000 */

    LOAD_U32(r5, 0x40010011)
    stw r5,PB_SDRAM_BAR2(r4)
    sync

    /* Make sure that PB_SDRAM_BAR2 decoder is set
      (to allow following immediate read from SDRAM) */
    lwz r5,PB_SDRAM_BAR2(r4)
    sync


init_done:

    /* All done. Restore LR and return. */
    mtlr    r19
    blr

#if (0)
/*===========================================================================
 init_cpu1

 This routine enables CPU1 on the dual-processor system.
===========================================================================*/

    .global enable_cpu1
enable_cpu1:

    lis r3,Tsi108_Base@ha       /* Get Grendel CSR Base Addr */
    addi    r3,r3,Tsi108_Base@l
    lwz r3,0(r3)                /* R3 = CSR Base Addr */
    ori r4,r3,TSI108_PB_REG_OFFSET
    lwz r3,PB_ARB_CTRL(r4)      /* Read PB Arbiter Control Register */
    ori r3,r3,0x0200            /* Set M1_EN bit */
    stw r3,PB_ARB_CTRL(r4)

    blr
#endif

/*===========================================================================
 enable_EI

 Enable CPU core external interrupt
===========================================================================*/

    .global enable_EI
enable_EI:
    mfmsr    r3
    ori      r3,r3,0x8000   /* set EE bit */
    mtmsr    r3
    blr

/*===========================================================================
 disable_EI

 Disable CPU core external interrupt
===========================================================================*/

    .global disable_EI
disable_EI:
    mfmsr   r3
    li  r4,-32768   /* aka "li  r4,0x8000" */
    andc r3,r3,r4   /* clear EE bit */
    mtmsr   r3
    blr

#ifdef ENABLE_SDRAM_ECC
/*===========================================================================
 enable_ECC

 enables SDRAM ECC
===========================================================================*/

    .global enable_ECC
enable_ECC:
    ori r4,r29,TSI108_SD_REG_OFFSET
    lwz r3,SD_ECC_CTRL(r4)      /* Read SDRAM ECC Control Register */
    ori r3,r3,0x0001            /* Set ECC_EN bit */
    stw r3,SD_ECC_CTRL(r4)
    blr

/*===========================================================================
 clear_ECC_err

 Clears all pending SDRAM ECC errors
 (normally after SDRAM scrubbing/initialization)
===========================================================================*/

    .global clear_ECC_err
clear_ECC_err:
    ori r4,r29,TSI108_SD_REG_OFFSET
/*    lwz r3,SD_INT_STATUS(r4)       Read SDRAM ECC Control Register */
    ori r3,r0,0x0030                /* ECC_UE_INT + ECC_CE_INT bits */
    stw r3,SD_INT_STATUS(r4)
    blr

#endif /* ENABLE_SDRAM_ECC */

#ifndef SDC_HARDCODED_INIT

/********************************************************************
 * SDRAM SPD Support
 */

#define	SD_I2C_CTRL1	(0x400)
#define	SD_I2C_CTRL2	(0x404)
#define SD_I2C_RD_DATA	(0x408)
#define SD_I2C_WR_DATA 	(0x40C)

/*
 * SDRAM SPD Support Macros
 */

#define SPD_DIMM0	(0x00000100)
#define SPD_DIMM1	(0x00000200) /* SPD_DIMM1 was 0x00000000 */

#define SPD_RDIMM			(0x01)
#define SPD_UDIMM			(0x02)

#define SPD_CAS_3			0x8
#define SPD_CAS_4			0x10
#define SPD_CAS_5			0x20

#define ERR_NO_DIMM_FOUND		(0xdb0)
#define ERR_TRAS_FAIL			(0xdb1)
#define ERR_TRCD_FAIL			(0xdb2)
#define ERR_TRP_FAIL			(0xdb3)
#define ERR_TWR_FAIL			(0xdb4)
#define ERR_UNKNOWN_PART		(0xdb5)
#define ERR_NRANK_INVALID		(0xdb6)
#define ERR_DIMM_SIZE			(0xdb7)
#define ERR_ADDR_MODE			(0xdb8)
#define ERR_RFRSH_RATE			(0xdb9)
#define ERR_DIMM_TYPE			(0xdba)
#define ERR_CL_VALUE			(0xdbb)
#define ERR_TRFC_FAIL			(0xdbc)

/* READ_SPD requirements:
 * byte - byte address in SPD device (0 - 255)
 * r3 = will return data read from I2C Byte location
 * r4 - unchanged (SDC base addr)
 * r5 - clobbered in routine (I2C status)
 * r10 - number of DDR slot where first SPD device is detected
 */

#define READ_SPD(byte_num)	\
	addis r3, 0, byte_num@l;\
	or	r3, r3, r10;\
	ori r3, r3, 0x0A;\
	stw r3, SD_I2C_CTRL1(r4);\
	li r3, I2C_CNTRL2_START;\
	stw r3, SD_I2C_CTRL2(r4);\
	eieio;\
	sync;\
	li r3, 0x100;\
1:				;\
	addic. r3, r3, -1;\
 	bne 1b;\
2:		  ;\
	lwz r5, SD_I2C_CTRL2(r4);\
	rlwinm.	r3,r5,0,23,23;\
	bne 2b;\
	rlwinm.	r3,r5,0,3,3;\
	lwz r3, SD_I2C_RD_DATA(r4)

#define SPD_MIN_RFRSH	(0x80)
#define SPD_MAX_RFRSH	(0x85)

refresh_rates: /* in nSec */
	.long	15625	/* Normal (0x80) */
	.long	3900	/* Reduced 0.25x (0x81) */
	.long	7800	/* Reduced 0.5x (0x82) */
	.long	31300	/* Extended 2x (0x83) */
	.long	62500	/* Extended 4x (0x84) */
	.long	125000	/* Extended 8x (0x85) */

/*===========================================================================
 * tsi108_sdram_spd
 *
 * Inittializes SDRAM Controller using DDR2 DIMM Serial Presence Detect data
 * Uses registers: r4 - SDC base address (not changed)
 *				   r9 - SDC clocking period in nSec
 * Changes registers: r3,r5,r6,r7,r8,r10,r11
 *==========================================================================*/

tsi108_sdram_spd:

	li r10,SPD_DIMM0
	xor	r11,r11,r11		/* DIMM Base Address: starts from 0 */

do_first_dimm:

	/**************************************
	 * Program Refresh Rate	Register
	 */

	READ_SPD(12)	/* get Refresh Rate */
	beq check_next_slot
	li r5, ERR_RFRSH_RATE
	cmpi 0,0,r3,SPD_MIN_RFRSH
	ble spd_fail
	cmpi 0,0,r3,SPD_MAX_RFRSH
	bgt spd_fail
	addi r3,r3,-SPD_MIN_RFRSH
	rlwinm r3,r3,2,0,31
	lis r5,refresh_rates@h
	ori r5,r5,refresh_rates@l
	lwzx r5,r5,r3	/* get refresh rate in nSec */
	divwu r5,r5,r9	/* calculate # of SDC clocks */
	stw r5,SD_REFRESH(r4)	/* Set refresh rate */
	sync

	/**************************************
	 * Program SD Timing Register
	 */

	li r7, 0		/* clear r7 prior parameter collection */

	READ_SPD(20)	/* get DIMM type: Registered or Unbuffered */
	beq	spd_read_fail
	li r5, ERR_DIMM_TYPE
	cmpi 0,0,r3,SPD_UDIMM
	beq do_cl
	cmpi 0,0,r3,SPD_RDIMM
	bne spd_fail
	oris r7,r7,0x1000	/* set SD_TIMING[DIMM_TYPE] bit */

do_cl:
	READ_SPD(18)	/* Get CAS Latency */
	beq	spd_read_fail
	li r5,ERR_CL_VALUE
	andi. r6,r3,SPD_CAS_3
	beq cl_4
	li r6,3
	b set_cl
cl_4:
	andi. r6,r3,SPD_CAS_4
	beq cl_5
	li r6,4
	b set_cl
cl_5:
	andi. r6,r3,SPD_CAS_5
	beq spd_fail
	li r6,5
set_cl:
	rlwimi r7,r6,24,5,7

	READ_SPD(30)	/* Get tRAS */
	beq	spd_read_fail
	divwu r6,r3,r9
	mullw r8,r6,r9
	subf. r8,r8,r3
	beq	set_tras
	addi r6,r6,1
set_tras:
	li r5,ERR_TRAS_FAIL
	cmpi 0,0,r6,0x0F	/* max supported value */
	bgt spd_fail
	rlwimi r7,r6,16,12,15

	READ_SPD(29)	/* Get tRCD */
	beq	spd_read_fail
	rlwinm r3,r3,30,2,31/* right shift tRCD by 2 bits as per DDR2 spec */
	divwu r6,r3,r9
	mullw r8,r6,r9
	subf. r8,r8,r3
	beq	set_trcd
	addi r6,r6,1
set_trcd:
	li r5,ERR_TRCD_FAIL
	cmpi 0,0,r6,0x07	/* max supported value */
	bgt spd_fail
	rlwimi r7,r6,12,17,19

	READ_SPD(27)	/* Get tRP value */
	beq	spd_read_fail
	rlwinm r3,r3,30,2,31	/* right shift tRP by 2 bits as per DDR2 spec */
	divwu r6,r3,r9
	mullw r8,r6,r9
	subf. r8,r8,r3
	beq	set_trp
	addi r6,r6,1
set_trp:
	li r5,ERR_TRP_FAIL
	cmpi 0,0,r6,0x07	/* max supported value */
	bgt spd_fail
	rlwimi r7,r6,8,21,23

	READ_SPD(36)	/* Get tWR value */
	beq	spd_read_fail
	rlwinm r3,r3,30,2,31	/* right shift tWR by 2 bits as per DDR2 spec */
	divwu r6,r3,r9
	mullw r8,r6,r9
	subf. r8,r8,r3
	beq	set_twr
	addi r6,r6,1
set_twr:
	addi r6,r6,-1		/* Tsi108 SDC always gives one extra clock */
	li r5,ERR_TWR_FAIL
	cmpi 0,0,r6,0x07	/* max supported value */
	bgt spd_fail
	rlwimi r7,r6,5,24,26

	READ_SPD(42)	/* Get tRFC */
	beq	spd_read_fail
	li r5, ERR_TRFC_FAIL
	/* Tsi108 spec: tRFC=(tRFC + 1)/2 */
	addi r3,r3,1
	rlwinm. r3,r3,31,1,31 /* divide by 2 */
	beq spd_fail
	divwu r6,r3,r9
	mullw r8,r6,r9
	subf. r8,r8,r3
	beq	set_trfc
	addi r6,r6,1
set_trfc:
	cmpi 0,0,r6,0x1F	/* max supported value */
	bgt spd_fail
	rlwimi r7,r6,0,27,31

	stw	r7,SD_TIMING(r4)
	sync

	/*=====================================================================
	 * The following two registers are set on per-DIMM basis.
	 * The SD_REFRESH and SD_TIMING settings are common for both DIMMS
	 *=====================================================================
	 */

do_each_dimm:

	/*****************************************
	 * Program SDRAM DIMM Control Register
	 */

	li r7, 0		/* clear r7 prior parameter collection */

	READ_SPD(13)		/* Get Primary SDRAM Width */
	beq	spd_read_fail
	cmpi 0,0,r3,4	/* Check for 4-bit SDRAM */
	beq do_nbank
	oris r7,r7,0x0010	/* Set MEM_WIDTH bit */

do_nbank:
	READ_SPD(17)		/* Get Number of banks on SDRAM device */
	beq	spd_read_fail
	/* Grendel only distinguish betw. 4 or 8-bank memory parts */
	li r5,ERR_UNKNOWN_PART	/* non-supported memory part */
	cmpi 0,0,r3,4
	beq do_nrank
	cmpi 0,0,r3,8
	bne spd_fail
	ori r7,r7,0x1000

do_nrank:
	READ_SPD(5)	/* Get # of Ranks */
	beq	spd_read_fail
	li r5,ERR_NRANK_INVALID
	andi. r6,r3,0x7	/* Use bits [2..0] only */
	beq do_addr_mode
	cmpi 0,0,r6,1
	bgt spd_fail
	rlwimi r7,r6,8,23,23

do_addr_mode:
	READ_SPD(4)	/* Get # of Column Addresses */
	beq	spd_read_fail
	li r5, ERR_ADDR_MODE
	andi. r3,r3,0x0f	/* cut off reserved bits */
	cmpi 0,0,r3,8
	ble spd_fail
	cmpi 0,0,r3,15
	bgt spd_fail
	addi r6,r3,-8	/* calculate ADDR_MODE parameter */
	rlwimi r7,r6,4,24,27	/* set ADDR_MODE field */

set_dimm_ctrl:
#ifdef SDC_AUTOPRECH_EN
    oris r7,r7,0x0001   /* set auto precharge EN bit */
#endif
	ori r7,r7,1	/* set ENABLE bit */
	cmpi 0,0,r10,SPD_DIMM0
	bne 1f
	stw r7,SD_D0_CTRL(r4)
	sync
	b set_dimm_bar
1:
	stw r7,SD_D1_CTRL(r4)
	sync


	/********************************************
	 * Program SDRAM DIMMx Base Address Register
	 */

set_dimm_bar:
	READ_SPD(5)		/* get # of Ranks */
	beq	spd_read_fail
	andi.r7,r3,0x7
	addi r7,r7,1
	READ_SPD(31)	/* Read DIMM rank density */
	beq	spd_read_fail
	rlwinm r5,r3,27,29,31
	rlwinm r6,r3,3,24,28
	or r5,r6,r5		/* r5 = Normalized Rank Density byte */
	lis r8, 0x0080		/* 128MB >> 4 */
	mullw r8,r8,r5		/* r8 = (rank_size >> 4) */
	mullw r8,r8,r7		/* r8 = (DIMM_size >> 4) */
	neg r7,r8
	rlwinm r7,r7,28,4,31
	or r7,r7,r11		/* set ADDR field */
	rlwinm r8,r8,12,20,31
	add r11,r11,r8		/* set Base Addr for next DIMM */

	cmpi 0,0,r10,SPD_DIMM0
	bne set_dimm1_size
	stw r7,SD_D0_BAR(r4)
	sync
	li r10,SPD_DIMM1
	READ_SPD(0)
	bne do_each_dimm
	b spd_done

set_dimm1_size:
	stw r7,SD_D1_BAR(r4)
	sync
spd_done:
	blr

check_next_slot:
	cmpi 0,0,r10,SPD_DIMM1
	beq spd_read_fail
	li r10,SPD_DIMM1
	b do_first_dimm
spd_read_fail:
	ori	r3,r0,0xdead
	b err_hung
spd_fail:
	li	r3,0x0bad
	sync
err_hung:   /* hang here for debugging */
    nop
    nop
    b err_hung

#endif /* !SDC_HARDCODED_INIT */