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/*
* reset AT91SAM9G20 as per errata
*
* (C) BitBox Ltd 2010
*
* unless the SDRAM is cleanly shutdown before we hit the
* reset register it can be left driving the data bus and
* killing the chance of a subsequent boot from NAND
*
* 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.
*/
#include <linux/linkage.h>
#include <asm/system.h>
#include <mach/hardware.h>
#include <mach/at91sam9_sdramc.h>
#include <mach/at91_rstc.h>
.arm
.globl at91sam9_alt_reset
at91sam9_alt_reset: mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #CR_I
mcr p15, 0, r0, c1, c0, 0 @ enable I-cache
ldr r0, .at91_va_base_sdramc @ preload constants
ldr r1, .at91_va_base_rstc_cr
mov r2, #1
mov r3, #AT91_SDRAMC_LPCB_POWER_DOWN
ldr r4, =AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST
.balign 32 @ align to cache line
str r2, [r0, #AT91_SDRAMC_TR] @ disable SDRAM access
str r3, [r0, #AT91_SDRAMC_LPR] @ power down SDRAM
str r4, [r1] @ reset processor
b .
.at91_va_base_sdramc:
.word AT91_VA_BASE_SYS + AT91_SDRAMC0
.at91_va_base_rstc_cr:
.word AT91_VA_BASE_SYS + AT91_RSTC_CR
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