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>

arch/arm/mach-omap2/common.h

@@ -182,6 +182,7 @@ static inline void __iomem *omap4_get_scu_base(void)
 
 extern void __init gic_init_irq(void);
 extern void omap_smc1(u32 fn, u32 arg);
+extern void __iomem *omap4_get_sar_ram_base(void);
 
 #ifdef CONFIG_SMP
 /* Needed for secondary core boot */

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 @@ static int __init omap_l2_cache_init(void)
 }
 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);

arch/arm/mach-omap2/omap4-sar-layout.h

@@ -0,0 +1,22 @@
+/*
+ * omap4-sar-layout.h: OMAP4 SAR RAM layout header file
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ *	Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef OMAP_ARCH_OMAP4_SAR_LAYOUT_H
+#define OMAP_ARCH_OMAP4_SAR_LAYOUT_H
+
+/*
+ * SAR BANK offsets from base address OMAP44XX_SAR_RAM_BASE
+ */
+#define SAR_BANK1_OFFSET		0x0000
+#define SAR_BANK2_OFFSET		0x1000
+#define SAR_BANK3_OFFSET		0x2000
+#define SAR_BANK4_OFFSET		0x3000
+
+#endif

arch/arm/plat-omap/include/plat/omap44xx.h

@@ -45,6 +45,7 @@
 #define OMAP44XX_WKUPGEN_BASE		0x48281000
 #define OMAP44XX_MCPDM_BASE		0x40132000
 #define OMAP44XX_MCPDM_L3_BASE		0x49032000
+#define OMAP44XX_SAR_RAM_BASE		0x4a326000
 
 #define OMAP44XX_MAILBOX_BASE		(L4_44XX_BASE + 0xF4000)
 #define OMAP44XX_HSUSB_OTG_BASE		(L4_44XX_BASE + 0xAB000)