linux/arch/arm/mach-at91/at91sam9g45_reset.S
Jean-Christophe PLAGNIOL-VILLARD 14f991a730 ARM: at91: Fix at91sam9g45 and at91cap9 reset
As on the other sam9 we need to cleanly shutdown the DDRAM before rebooting.

On those SoC the SDRAM/DDRAM controller is different. So, the assembly code
ends up being not cleanly combined with previous at91sam9_alt_restart function.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2012-01-20 17:22:50 +01:00

41 lines
981 B
ArmAsm

/*
* 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/at91sam9_ddrsdr.h>
#include <mach/at91_rstc.h>
.arm
.globl at91sam9g45_restart
at91sam9g45_restart:
ldr r0, .at91_va_base_sdramc0 @ preload constants
ldr r1, =at91_rstc_base
ldr r1, [r1]
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 .
.at91_va_base_sdramc0:
.word AT91_VA_BASE_SYS + AT91_DDRSDRC0