ARM: OMAP4: PM: Add SAR RAM support

This patch adds SAR RAM support on OMAP4430. SAR RAM used to save
and restore the HW context in low power modes.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/mach-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c
index 4a3d289..2489f5b 100644
--- a/arch/arm/mach-omap2/omap4-common.c
+++ b/arch/arm/mach-omap2/omap4-common.c
@@ -24,11 +24,14 @@
 #include <mach/hardware.h>
 
 #include "common.h"
+#include "omap4-sar-layout.h"
 
 #ifdef CONFIG_CACHE_L2X0
 static void __iomem *l2cache_base;
 #endif
 
+static void __iomem *sar_ram_base;
+
 void __init gic_init_irq(void)
 {
 	void __iomem *omap_irq_base;
@@ -118,3 +121,30 @@
 }
 early_initcall(omap_l2_cache_init);
 #endif
+
+void __iomem *omap4_get_sar_ram_base(void)
+{
+	return sar_ram_base;
+}
+
+/*
+ * SAR RAM used to save and restore the HW
+ * context in low power modes
+ */
+static int __init omap4_sar_ram_init(void)
+{
+	/*
+	 * To avoid code running on other OMAPs in
+	 * multi-omap builds
+	 */
+	if (!cpu_is_omap44xx())
+		return -ENOMEM;
+
+	/* Static mapping, never released */
+	sar_ram_base = ioremap(OMAP44XX_SAR_RAM_BASE, SZ_16K);
+	if (WARN_ON(!sar_ram_base))
+		return -ENOMEM;
+
+	return 0;
+}
+early_initcall(omap4_sar_ram_init);