diff options
Diffstat (limited to 'arch/arm/mach-at91/at91sam9g45_reset.S')
| -rw-r--r-- | arch/arm/mach-at91/at91sam9g45_reset.S | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/at91sam9g45_reset.S b/arch/arm/mach-at91/at91sam9g45_reset.S new file mode 100644 index 000000000000..0468be10980b --- /dev/null +++ b/arch/arm/mach-at91/at91sam9g45_reset.S @@ -0,0 +1,40 @@ +/* + * 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 |