267 lines
		
	
	
		
			9.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
			
		
		
	
	
			267 lines
		
	
	
		
			9.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
/******************************************************************************
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 *   This source code is dual-licensed.  You may use it under the terms of the
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 *   GNU General Public License version 2, or under the license below.
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 *
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 *	 This source code has been made available to you by IBM on an AS-IS
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 *	 basis.	 Anyone receiving this source is licensed under IBM
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 *	 copyrights to use it in any way he or she deems fit, including
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 *	 copying it, modifying it, compiling it, and redistributing it either
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 *	 with or without modifications.	 No license under IBM patents or
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 *	 patent applications is to be implied by the copyright license.
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 *
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 *	 Any user of this software should understand that IBM cannot provide
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 *	 technical support for this software and will not be responsible for
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 *	 any consequences resulting from the use of this software.
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 *
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 *	 Any person who transfers this source code or any derivative work
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 *	 must include the IBM copyright notice, this paragraph, and the
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 *	 preceding two paragraphs in the transferred software.
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 *
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 *	 COPYRIGHT   I B M   CORPORATION 1995
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 *	 LICENSED MATERIAL  -  PROGRAM PROPERTY OF I B M
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 *
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 *****************************************************************************/
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#include <config.h>
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#include <asm/ppc4xx.h>
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#define _LINUX_CONFIG_H 1	/* avoid reading Linux autoconf.h file	*/
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#include <ppc_asm.tmpl>
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#include <ppc_defs.h>
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#include <asm/cache.h>
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#include <asm/mmu.h>
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/******************************************************************************
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 * Function:	ext_bus_cntlr_init
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 *
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 * Description:	Configures EBC Controller and a few basic chip selects.
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 *
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 *		CS0 is setup to get the Boot Flash out of the addresss range
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 *		so that we may setup a stack.  CS7 is setup so that we can
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 *		access and reset the hardware watchdog.
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 *
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 *		IMPORTANT: For pass1 this code must run from
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 *		cache since you can not reliably change a peripheral banks
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 *		timing register (pbxap) while running code from that bank.
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 *		For ex., since we are running from ROM on bank 0, we can NOT
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 *		execute the code that modifies bank 0 timings from ROM, so
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 *		we run it from cache.
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 *
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 * Notes:	Does NOT use the stack.
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 *****************************************************************************/
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	.section ".text"
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	.align	2
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	.globl	ext_bus_cntlr_init
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	.type	ext_bus_cntlr_init, @function
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ext_bus_cntlr_init:
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	mflr	r0
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	/********************************************************************
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	 * Prefetch entire ext_bus_cntrl_init function into the icache.
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	 * This is necessary because we are going to change the same CS we
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	 * are executing from.  Otherwise a CPU lockup may occur.
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	 *******************************************************************/
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	bl	..getAddr
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..getAddr:
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	mflr	r3			/* get address of ..getAddr */
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	/* Calculate number of cache lines for this function */
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	addi	r4, 0, (((.Lfe0 - ..getAddr) / CONFIG_SYS_CACHELINE_SIZE) + 2)
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	mtctr	r4
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..ebcloop:
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	icbt	r0, r3			/* prefetch cache line for addr in r3*/
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	addi	r3, r3, CONFIG_SYS_CACHELINE_SIZE /* move to next cache line */
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	bdnz	..ebcloop		/* continue for $CTR cache lines */
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	/********************************************************************
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	 * Delay to ensure all accesses to ROM are complete before changing
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	 * bank 0 timings. 200usec should be enough.
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	 * 200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles.
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	 *******************************************************************/
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	addis	r3, 0, 0x0
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	ori	r3, r3, 0xA000		/* wait 200us from reset */
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	mtctr	r3
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..spinlp:
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	bdnz	..spinlp		/* spin loop */
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	/********************************************************************
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	 * Setup External Bus Controller (EBC).
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	 *******************************************************************/
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	addi	r3, 0, EBC0_CFG
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	mtdcr	EBC0_CFGADDR, r3
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	addis	r4, 0, 0xb040		/* Device base timeout = 1024 cycles */
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	ori	r4, r4, 0x0		/* Drive CS with external master */
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	mtdcr	EBC0_CFGDATA, r4
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	/********************************************************************
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	 * Change PCIINT signal to PerWE
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	 *******************************************************************/
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	mfdcr	r4, CPC0_CR1
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	ori	r4, r4, 0x4000
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	mtdcr	CPC0_CR1, r4
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	/********************************************************************
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	 * Memory Bank 0 (Flash Bank 0) initialization
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	 *******************************************************************/
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	addi	r3, 0, PB1AP
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	mtdcr	EBC0_CFGADDR, r3
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	addis	r4, 0, CONFIG_SYS_W7O_EBC_PB0AP@h
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	ori	r4, r4, CONFIG_SYS_W7O_EBC_PB0AP@l
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	mtdcr	EBC0_CFGDATA, r4
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	addi	r3, 0, PB0CR
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	mtdcr	EBC0_CFGADDR, r3
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	addis	r4, 0, CONFIG_SYS_W7O_EBC_PB0CR@h
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	ori	r4, r4, CONFIG_SYS_W7O_EBC_PB0CR@l
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	mtdcr	EBC0_CFGDATA, r4
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	/********************************************************************
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	 * Memory Bank 7 LEDs - NEEDED BECAUSE OF HW WATCHDOG AND LEDs.
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	 *******************************************************************/
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	addi	r3, 0, PB7AP
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	mtdcr	EBC0_CFGADDR, r3
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	addis	r4, 0, CONFIG_SYS_W7O_EBC_PB7AP@h
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	ori	r4, r4, CONFIG_SYS_W7O_EBC_PB7AP@l
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	mtdcr	EBC0_CFGDATA, r4
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	addi	r3, 0, PB7CR
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	mtdcr	EBC0_CFGADDR, r3
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	addis	r4, 0, CONFIG_SYS_W7O_EBC_PB7CR@h
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	ori	r4, r4, CONFIG_SYS_W7O_EBC_PB7CR@l
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	mtdcr	EBC0_CFGDATA, r4
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	/* We are all done */
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	mtlr	r0			/* Restore link register */
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	blr				/* Return to calling function */
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.Lfe0:	.size	ext_bus_cntlr_init,.Lfe0-ext_bus_cntlr_init
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/* end ext_bus_cntlr_init() */
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/******************************************************************************
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 * Function:	sdram_init
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 *
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 * Description:	Configures SDRAM memory banks.
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 *
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 *		Serial Presence Detect, "SPD," reads the SDRAM EEPROM
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 *		via the IIC bus and then configures the SDRAM memory
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 *		banks appropriately. If Auto Memory Configuration is
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 *		is not used, it is assumed that a 4MB 11x8x2, non-ECC,
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 *		SDRAM is soldered down.
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 *
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 * Notes:	Expects that the stack is already setup.
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 *****************************************************************************/
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	.section ".text"
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	.align	2
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	.globl	sdram_init
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	.type	sdram_init, @function
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sdram_init:
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	/* save the return info on stack */
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	mflr	r0			/* Get link register */
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	stwu	r1, -8(r1)		/* Save back chain and move SP */
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	stw	r0, +12(r1)		/* Save link register */
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	/*
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	 * First call spd_sdram to try to init SDRAM according to the
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	 * contents of the SPD EEPROM.  If the SPD EEPROM is blank or
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	 * erronious, spd_sdram returns 0 in R3.
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	 */
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	li	r3,0
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	bl	spd_sdram
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	addic.	r3, r3, 0		/* Check for error, save dram size */
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	bne	..sdri_done		/* If it worked, we're done... */
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	/********************************************************************
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	 * If SPD detection fails, we'll default to 4MB, 11x8x2, as this
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	 * is the SMALLEST SDRAM size the 405 supports.  We can do this
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	 * because W7O boards have soldered on RAM, and there will always
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	 * be some amount present.  If we were using DIMMs, we should hang
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	 * the board instead, since it doesn't have any RAM to continue
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	 * running with.
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	 *******************************************************************/
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	/*
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	 * Disable memory controller to allow
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	 * values to be changed.
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	 */
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	addi    r3, 0, SDRAM0_CFG
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	mtdcr   SDRAM0_CFGADDR, r3
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	addis   r4, 0, 0x0
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	ori     r4, r4, 0x0
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	mtdcr   SDRAM0_CFGDATA, r4
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	/*
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	 * Set MB0CF for ext bank 0. (0-4MB) Address Mode 5 since 11x8x2
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	 * All other banks are disabled.
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	 */
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	addi	r3, 0, SDRAM0_B0CR
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	mtdcr	SDRAM0_CFGADDR, r3
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	addis	r4, 0, 0x0000		/* BA=0x0, SZ=4MB */
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	ori	r4, r4, 0x8001		/* Mode is 5, 11x8x2or4, BE=Enabled */
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	mtdcr	SDRAM0_CFGDATA, r4
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	/* Clear MB1CR,MB2CR,MB3CR to turn other banks off */
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	addi	r4, 0, 0		/* Zero the data reg */
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	addi	r3, r3, 4		/* Point to MB1CF reg */
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	mtdcr	SDRAM0_CFGADDR, r3		/* Set the address */
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	mtdcr	SDRAM0_CFGDATA, r4		/* Zero the reg */
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	addi	r3, r3, 4		/* Point to MB2CF reg */
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	mtdcr	SDRAM0_CFGADDR, r3		/* Set the address */
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	mtdcr	SDRAM0_CFGDATA, r4		/* Zero the reg */
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	addi	r3, r3, 4		/* Point to MB3CF reg */
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	mtdcr	SDRAM0_CFGADDR, r3		/* Set the address */
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	mtdcr	SDRAM0_CFGDATA, r4		/* Zero the reg */
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	/********************************************************************
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	 * Set the SDRAM Timing reg, SDTR1 and the refresh timer reg, RTR.
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	 * To set the appropriate timings, we assume sdram is
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	 * 100MHz (pc100 compliant).
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	 *******************************************************************/
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	/*
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	 * Set up SDTR1
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	 */
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	addi    r3, 0, SDRAM0_TR
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	mtdcr   SDRAM0_CFGADDR, r3
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	addis   r4, 0, 0x0086		/* SDTR1 value for 100Mhz */
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	ori     r4, r4, 0x400D
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	mtdcr   SDRAM0_CFGDATA, r4
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	/*
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	 * Set RTR
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	 */
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	addi    r3, 0, SDRAM0_RTR
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	mtdcr   SDRAM0_CFGADDR, r3
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	addis   r4, 0, 0x05F0		/* RTR refresh val = 15.625ms@100Mhz */
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	mtdcr   SDRAM0_CFGDATA, r4
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	/********************************************************************
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	 * Delay to ensure 200usec have elapsed since reset. Assume worst
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	 * case that the core is running 200Mhz:
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	 *	  200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles
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	 *******************************************************************/
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	addis   r3, 0, 0x0000
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	ori     r3, r3, 0xA000		/* Wait 200us from reset */
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	mtctr   r3
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..spinlp2:
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	bdnz    ..spinlp2		/* spin loop */
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	/********************************************************************
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	 * Set memory controller options reg, MCOPT1.
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	 *******************************************************************/
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	addi    r3, 0, SDRAM0_CFG
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	mtdcr   SDRAM0_CFGADDR, r3
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	addis   r4, 0, 0x80E0		/* DC_EN=1,SRE=0,PME=0,MEMCHK=0 */
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	ori     r4, r4, 0x0000		/* REGEN=0,DRW=00,BRPF=01,ECCDD=1 */
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	mtdcr   SDRAM0_CFGDATA, r4		/* EMDULR=1 */
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..sdri_done:
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	/* restore and return */
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	lwz	r0, +12(r1)		/* Get saved link register */
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	addi	r1, r1, +8		/* Remove frame from stack */
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	mtlr	r0			/* Restore link register */
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	blr				/* Return to calling function */
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.Lfe1:	.size	sdram_init,.Lfe1-sdram_init
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/* end sdram_init() */
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