[PATCH 5/6] ARM: at91: add ram controller DT support

quoted

diff --git a/arch/arm/mach-at91/include/mach/at91sam9x5.h b/arch/arm/mach-at91/include/mach/at91sam9x5.h
index a297a77..88e43d5 100644
--- a/arch/arm/mach-at91/include/mach/at91sam9x5.h
+++ b/arch/arm/mach-at91/include/mach/at91sam9x5.h

@@ -55,11 +55,6 @@
 #define AT91SAM9X5_BASE_USART2	0xf8024000
 
 /*
- * System Peripherals
- */
-#define AT91SAM9X5_BASE_DDRSDRC0	0xffffe800
-
-/*
  * Base addresses for early serial code (uncompress.h)
  */
 #define AT91_DBGU	AT91_BASE_DBGU0

diff --git a/arch/arm/mach-at91/setup.c b/arch/arm/mach-at91/setup.c
index 3e48b59..f86450d 100644
--- a/arch/arm/mach-at91/setup.c
+++ b/arch/arm/mach-at91/setup.c

@@ -315,12 +315,33 @@ static void at91_dt_rstc(void)
 	of_node_put(np);
 }
 
+static struct of_device_id ramc_ids[] = {
+	{ .compatible = "atmel,at91sam9260-sdramc" },
+	{ .compatible = "atmel,at91sam9g45-ddramc" },
+	{ /*sentinel*/ }
+};
+
+static void at91_dt_ramc(void)
+{
+	struct device_node *np;
+
+	np = of_find_matching_node(NULL, ramc_ids);
+	if (!np)
+		panic("unable to find compatible ram conroller node in dtb\n");

You really can't boot if this fails? A WARN is better if it allows you
to boot until at least your console is actually up.

if the restart is called you will have a oops so no it's a basic mandatory
device on at91

Best Regards,
J.