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/at91sam9_sdramc.h>
19#include <mach/at91_rstc.h>
20
21			.arm
22
23			.globl	at91sam9_alt_restart
24
25at91sam9_alt_restart:	ldr	r0, .at91_va_base_sdramc	@ preload constants
26			ldr	r1, =at91_rstc_base
27			ldr	r1, [r1]
28
29			mov	r2, #1
30			mov	r3, #AT91_SDRAMC_LPCB_POWER_DOWN
31			ldr	r4, =AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST
32
33			.balign	32				@ align to cache line
34
35			str	r2, [r0, #AT91_SDRAMC_TR]	@ disable SDRAM access
36			str	r3, [r0, #AT91_SDRAMC_LPR]	@ power down SDRAM
37			str	r4, [r1, #AT91_RSTC_CR]		@ reset processor
38
39			b	.
40
41.at91_va_base_sdramc:
42	.word AT91_VA_BASE_SYS + AT91_SDRAMC0
43