1/* 2 * reset AT91SAM9G20 as per errata 3 * 4 * (C) BitBox Ltd 2010 5 * 6 * unless the SDRAM is cleanly shutdown before we hit the 7 * reset register it can be left driving the data bus and 8 * killing the chance of a subsequent boot from NAND 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 */ 15 16#include <linux/linkage.h> 17#include <mach/hardware.h> 18#include <mach/at91_ramc.h> 19#include "at91_rstc.h" 20 21 .arm 22 23 .globl at91sam9_alt_restart 24 25at91sam9_alt_restart: ldr r0, =at91_ramc_base @ preload constants 26 ldr r0, [r0] 27 ldr r4, =at91_rstc_base 28 ldr r1, [r4] 29 30 mov r2, #1 31 mov r3, #AT91_SDRAMC_LPCB_POWER_DOWN 32 ldr r4, =AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST 33 34 .balign 32 @ align to cache line 35 36 str r2, [r0, #AT91_SDRAMC_TR] @ disable SDRAM access 37 str r3, [r0, #AT91_SDRAMC_LPR] @ power down SDRAM 38 str r4, [r1, #AT91_RSTC_CR] @ reset processor 39 40 b . 41