diff options
Diffstat (limited to 'arch/arm/mach-at91/at91sam9_alt_reset.S')
| -rw-r--r-- | arch/arm/mach-at91/at91sam9_alt_reset.S | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/at91sam9_alt_reset.S b/arch/arm/mach-at91/at91sam9_alt_reset.S new file mode 100644 index 00000000..7af2e108 --- /dev/null +++ b/arch/arm/mach-at91/at91sam9_alt_reset.S @@ -0,0 +1,40 @@ +/* + * 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 <mach/hardware.h> +#include <mach/at91_ramc.h> +#include <mach/at91_rstc.h> + + .arm + + .globl at91sam9_alt_restart + +at91sam9_alt_restart: ldr r0, =at91_ramc_base @ preload constants + ldr r0, [r0] + ldr r4, =at91_rstc_base + ldr r1, [r4] + + 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, #AT91_RSTC_CR] @ reset processor + + b . |