aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-at91/at91sam9g45_reset.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-at91/at91sam9g45_reset.S')
-rw-r--r--arch/arm/mach-at91/at91sam9g45_reset.S40
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 00000000000..0468be10980
--- /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