linux-sg2042/arch/arm/mach-at91/at91sam9g45_reset.S

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/*
* reset AT91SAM9G45 as per errata
*
* Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcosoft.com>
*
* 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
*
* GPLv2 Only
*/
#include <linux/linkage.h>
#include <mach/hardware.h>
#include <mach/at91_ramc.h>
#include <mach/at91_rstc.h>
.arm
.globl at91sam9g45_restart
at91sam9g45_restart:
ldr r5, =at91_ramc_base @ preload constants
ldr r0, [r5]
ldr r4, =at91_rstc_base
ldr r1, [r4]
mov r2, #1
mov r3, #AT91_DDRSDRC_LPCB_POWER_DOWN
ldr r4, =AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST
.balign 32 @ align to cache line
str r2, [r0, #AT91_DDRSDRC_RTR] @ disable DDR0 access
str r3, [r0, #AT91_DDRSDRC_LPR] @ power down DDR0
str r4, [r1, #AT91_RSTC_CR] @ reset processor
b .