Merge with git://www.denx.de/git/u-boot.git

1 files changed, 918 insertions, 0 deletions

diff --git a/board/mpc7448hpc2/asm_init.S b/board/mpc7448hpc2/asm_init.S
new file mode 100644
index 0000000..a7a40a1
--- /dev/null
+++ b/board/mpc7448hpc2/asm_init.S
@@ -0,0 +1,918 @@
+/*
+ * (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
+
+	/* def CONFIG_DUAL_CPU
+	 * For MPC74xx processor, use MSSCR0[ID] bit to identify CPU number.
+	 */
+#if(1)
+	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)) /* 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(r5,0x00002481)	/* 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,r5,0x0001	/* Set pipeline depth */
+	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
+	/* wait until SDRAM initialization is complete */
+	beq	wait_init_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)
+	 */
+
+	/* BA=0,Size=512MB, ENable, No Addr.Translation */
+	LOAD_U32(r5, 0x00000011)
+	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.
+	 * Now there is only one processor in the 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
+	/* 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
+	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
+	/* right shift tRCD by 2 bits as per DDR2 spec */
+	rlwinm	r3,r3,30,2,31
+	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 */