43 строки
1.1 KiB
ArmAsm
43 строки
1.1 KiB
ArmAsm
/*
|
|
* 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/at91sam9_sdramc.h>
|
|
#include <mach/at91_rstc.h>
|
|
|
|
.arm
|
|
|
|
.globl at91sam9_alt_restart
|
|
|
|
at91sam9_alt_restart: ldr r0, .at91_va_base_sdramc @ preload constants
|
|
ldr r1, =at91_rstc_base
|
|
ldr r1, [r1]
|
|
|
|
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 .
|
|
|
|
.at91_va_base_sdramc:
|
|
.word AT91_VA_BASE_SYS + AT91_SDRAMC0
|